Numbers, Distribution and Habitat Status of The Amur Tiger
6/14/97
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RELAYED TEXT STARTS HERE:
Headline: Numbers, Distribution and Habitat Status of The Amur Tiger
Source: glas:mishaj in cdp:env.siberia
Date: 6/14/97
Authors: E.N. Matyllshkin, 0.G. Pikunov, Y.M. Dunishenko, D.G. Miquelle,
l.G, Nikolaev, E.N. Smirnov, G.P. Salkina, V.K. Abramov, V.I. Basylllikov,
V.G. Yyudin, and V.G. Korkishko
NUMBERS, DISTRIBUTION AND HABITAT STATUS OF THE AMUR TIGER IN THE RUSSIAN
FAR EAST:
Conducted by:
E.N. Matyllshkin, 0.G. Pikunov, Y.M. Dunishenko, D.G. Miquelle,
l.G, Nikolaev, E.N. Smirnov, G.P. Salkina, V.K. Abramov, V.I.
Basylllikov, V.G. Yyudin, and V.G. Korkishko
Conducted under the auspices of the USAID Russian Far East Environmental
Policy and Technology Project
1996
Final report to the USAID Russian Far
East Environmental Policy and Technology Project.
Acknowledgments. We wish to thank USAID, which provided the
financial, logistical, and administrative support necessary to
conduct this project, and to World Wide Fund for Nature- Germany*
which provided key financial assistance. We also wish to thank
Primorsky and Khabarovsky Krai Administrations for their support
of this project. Anastasia Strokova translated the text into
English (with editing by Dale Miquelle) and Katerina Nikolaeva
developed the computer database and made editorial corrections to
text. Finally, our sincere thanks to the many forest guards,
conservation officers, and hunters who provided their time,
talent, and knowledge to this census.
Table of Contents
1. Introduction...............................................1
2. Study area and conditions for the census...................4
3. Methods....................................................6
4. Results...................................................11
4.1. Number and distribution of tigers in the Russian Far
East.................................................11
Primorsky Krai....................................11
Khabarovsky Krai..................................17
4.2. Analysis of data on litter size..................... 20
4.3. Data on tiger mortality..............................22
5. Discussion of results and conclusions.................... 23
Literature Cited.............................................26
1. INTRODUCTION.
Russia has primary responsibility for conservation of the Amu or
Siberian tiger (Panthera tigrus altaica). One of five remaining
tiger subspecies of the original eight recognized subspecies, the
Amur tiger is distinguishable by a number of morphological and
ecological traits. At least 80-90% of the world-wide population
of this animal resides in the Russian Far East. There are
probably no more than 20 Amur tigers inhabiting adjacent regions
of northeast China (Lu Binxin 1993), and there are only
unconfirmed reports that Amur tigers remain on the Korean
peninsula.
For the last one hundred years the Amur tiger population in
Russia has fluctuated dramatically, from a relatively high number
at the beginning of the century through a critical low in the
late 1930's and early 1940's, when an estimated 20-30 animals
remained in the Russian Far East (Kaplanov 1948). Although
Kaplanov's estimate may be conservative, a population of probably
no more than 50 (in the early 1940's) gradually increased up to
the 1990's, and may have reached an estimated 300-400
individuals. According to the data obtained from the census
conducted in the winter of 1984-1985, there were approximately
250 tigers found in the entire Russian Far East (Pikunov 1990),
and a questionnaire survey indicated 338-350 tigers in 1990 in
Primorye alone (Mescheryakov and Kucherenko 1990) (Table 1). The
main factor responsible for the near extinction of this
subspecies in the middle of this century was human persecution.
The implementation of protective legislation in 1947 was a
turning point for the tiger in Russia. Since that time
conservation of this subspecies has become a key priority for
regional and federal ecological policies. The latest confirmation
of this fact is the Russian Federation's Resolution #795, "On the
conservation of Amur tigers and other rare and endangered species
of wild flora and fauna on the territory of Primorsky and
Khabarovsky Krais," and the approval in July, 1996 by the Russian
Federation Ministry of Environmental and Natural Resources
Protection of a base document developed at a fine scale
resolution, "Strategy for Amur Tiger Conservation in Russia".
Although this species is not immediately threatened with
extinction, there is serious concern for its future. With the
exceptions of zapovedniks (reserves) and other protected areas,
most forest lands within the range of tigers have been subjected
logging operations. Ungulate numbers have decreased everywhere,
resulting in an obvious imbalance between populations of key prey
species and the tiger itself Most importantly, axiomatic increase
in poaching has occurred since the beginning of the 1990's, which
is largely a result of new opportunities for selling tiger bones.
Tiger products, believed to have powerful medicinal properties,
are sold in the majority of East-Asian countries. As a result, it
is estimated that poaching has resulted in a 10% annual removal
rate for the last five years (Pikunov 1994), equaling or perhaps
exceeding reproductive potential of the population. The present
situation is unlikely to change in the near future. Thus,
monitoring the status of the population, and possible changes in
tiger distribution, is vitally important.
Assessing the status of the Amur tiger population may be
conducted in two possible ways* by sampling key count units, and
then extrapolating to the entire population, or simultaneously
censuring the entire range of tigers. Data collection on key
sample units does not require as great a financial expense, and
could be conducted at regular intervals. However, when conducting
a census on rare and sparsely distributed species there is the
potential risk of serious mistakes when extrapolating to large,
unsampled regions. On the other hand, a detailed range assessment
is a costly process that is difficult to organize, and is
therefore, likely to be repeated only at infrequent intervals.
However, a full survey of the existing range of the Amur tiger is
the only way to get a complete picture of the present status of
the population (with details on its present distribution), and an
assessment of population dynamics. Most importantly, a full range
survey provides a "snapshot" of the whole range of the tiger
population, and its internal structure.
Two methods have been used over the last half century to assess
the status of the tiger population in the Russian Far East,
starting with the pioneering work of L. G. Kaplanov (1948): 1)
special census efforts, with focus on key areas - such as in
zapovedniks; and 2) censuses over large territories. Wide-ranging
censuses of tigers in Primorsky and Khabarovsky Krais have been
frequently conducted in the last 30 years, and over time the
range of territory covered has increased, and data collection has
been more standardized (Table 1). In comparison with similar work
on tigers in south Asia, censuses in the Russian Far East have a
great advantage in that they are conducted during winter when an
almost continuous snow cover provides an excellent tracking
media. For this reason, and the fact that track registration is
mostly performed by professional hunters working on hunting units
they are intimately familiar with, the estimates of tiger
population size in Russia, including all the inevitable
systematic errors, is still much more reliable than similar
assessments in India or Sumatra (Sankhala 1979, Karanth 1987,
1993, Faust and Tilson 1994, Ramono and SantiapUlai 1994).
The need for a tiger census over its entire range was stated in
the resolution of the International symposium "Amur tiger -
problems of population conservation" (Khabarovsk, March, 1993),
in the "Amur Tiger Program", adopted by an international working
group (Gaivoron, June 1994), and in the resolution of the
international conference "Ecology and conservation of the Amur
tiger" (Vladivostok, March 1995). In the Amur Tiger Program, it
was emphasized that "accurate and current information about the
condition of the Amur tiger population, and about threats to its
habitat is fundamental for the evaluation of population viability
and for the practical realization of conservation plan".
The objectives of the project "Numbers, distribution, and habitat
status of the Amur tiger in the Russian Far East," were:
---- to estimate the number of tigers, and to delineate
characteristics of then- distribution within existing range,
---- to determine areas of minimum and maximum densities, to
define areas at risk of fragmentation, and to assess the
integrity of existing habitat;
---- to characterize, as much as possible, the sex-age structure
of the Amur tiger population and to determine its reproductive
potential;
----to assess the present status (and long-term trends) of the
Amur tiger population, and to develop recommendations for
long-term conservation of the species in the Russian Far East.
E. N. Matyushkin was appointed head of the project (Moscow State
University and The Commission on Large Predators, TO RAN), 1. 0.
Suslov was responsible for overseeing the tiger census for the
Primorsky Krai Administration (Vladivostok, Primorsky Krai
Hunting Board), D. G. Pikunov was Primorsky Krai Coordinator
(Vladivostok, Pacific Institute of Geography DVO RAN), and Y. M.
Dunishenko was Khabarovsky Krai Coordinator (Khabarovsk, DVO
VNIIOZ). Seven additional specialists with extensive e*erience in
similar projects acted as regional coordinators: V. K. Abramov
(Ussurisky Zapovednik), V. 1. Bazylnikov (Primorsky Krai Hunting
Board), V. G. Korkishko (Kedrovya Pad Zapovednik), I. G. Nikolaev
(Institute of Biology and Soils, DVO RAN), G. P. Salkina
(Lazovsky Zapovednik), E. N. Smimov (Sikhote-Aim Zapovednik), and
V. G. Yudin (Institute of Biology and Soils, DVO RAN).
D. G. Miquelle, biodiversity manager of the USAID Russian Far
East Environmental Policy and Technology (EFT) Project,
coordinated tile project. Miquelle oversaw organization and
collection of data, coordinated discussion of results with
coordinators, and prepared data for input into a GIS database,
which was developed by a group of specialists including W. T.
Merrill (Co-operative Fish and Wildlife Research Unit, University
of Idaho) and S. Krasnepeev (The Institute of Geography and
Scientific Research Association of the Primorsky Regional
Association of Indigenous Peoples', T. Bechtold (The Ecology
Center, Missoula Montana)* and V. Kulikov (The Wildlife
Foundation of Khabarovsk).
Financial, logistical, and administrative support for "Tiger
census-96" was provided by the USAID Russian Far East
Environmental Policy and Technology Project. Additional financial
assistance was provided by World Wide Fund for Nature
(WWF-Germany).
2. STUDY AREA AND CONDITIONS FOR THE CENSUS
The entire territory inhabited by tigers in the Russian Far East
that was incorporated into the census, stretches north to south
for almost one thousand kilometers. This region is mainly
represented by the Sikhote-Aim Mountain Range, which varies from
200-300 kilometers in width at different latitudes. Also included
in the census was the edge of Eastern-Manchurian mountain system,
which crosses into Russia from China at several places in
south-west Primorye (Pogranichny, Khankaisky, Ussurisky,
Nadezhdinsky, and Khasansky Raions), and where tigers were
present in earlier censuses. The total area covered in 1995-96
winter census was 193,520 km/2, during the simultaneous count
(see below) on February 10-12, 134,621 km/2 were covered. A
synchronized census, employing one technique, over the entire
range of the Amur tiger is unprecedented.
Practically the entire region censured is mountainous, as the
Sikhote-Aim Mountains provide the majority of the remaining
habitat for the Amur tiger. Generally, peaks are 500- 800 meters
above the sea level, with only a few reaching 1000 m or more.
River basins are characterized by a *oxlike" profile, with flat
river bottoms ranging in width from several tens of meters up to
a kilometer and more. Mountain ridges are straight and can extend
without dramatic changes in height for considerable distances,
while slopes are moderately to very steep. Ridges rise above
rivers and creeks 300-500 m, but 250-300 m is more typical. Large
cliffs are not numerous and distributed sporadically, although
small rocky outcrops and isolated cliffs are usually located on
steep river slopes, especially on narrow spurs stretching down to the
basins.
The territory included in the census is completely forest
covered. Typical tiger habitats are valley and mountain "cedar,"
Korean pine (Pinus koraiensis) - broadleaved forests with a
complex composition and structure. The large majority of these
forests have been selectively logged at various times in the
past. The past history of logging and fire has resulted in much
of the region being comprised of secondary broad-leaved forests,
especially oak (Quercus spp.) and birch (Betula spp.) stands. A
broad zone of oak and other secondary forests have formed along
the periphery of Sikhote-Ann and at the lower elevations,
including lands managed for agricultural production. Above
700-800 m, spruce (Pices spp.)-fir (Abies spp.) forests prevail
in central Sikhote-Aim. This elevational boundary for the
predominantly coniferous forest type increases to the south, and
decreases northward, until, at 47*20" latitude, coniferous
forests occur along the coastline.
The main forms of economic activity in the Sikhote-Aim ecosystem
are logging and hunting. There are also regions with intensive
mining activity, primarily in the remote parts of Sikhote-Ann.
Wide-ranging agricultural activity occurs on the periphery of the
Sikhote-Aim Mountains, and in the interior along the wide river
basins. Settlements are scattered throughout tiger range, but
tile associated road network is dense in some places,
especially where intensive logging has occurred.
The most important tiger habitat - primary and secondary Korean
pine- broadleaved forests - occupy the central position in the
sequence of landscape changes associated with elevational
changes. These forest types are squeezed between a strip of
almost unbroken agricultural lands along the periphery of
Sikhote-Aim, and the coniferous forests at higher elevations in
the interior. Accordingly, in the northern limits of tiger range,
suitable habitat extends in the form of two "peninsulas", one on
the interior, western macroslope of the Sikhote-Ahn mountains,
the second along the coastline (Figure 2).
This general knowledge of tiger habitat formed the basis for
developing a census network: count units in each region began at
the edge of agricultural lands and continued into the upper
reaches of basins, excluding large tracts of spruce-fir "taiga",
although in some northern basins (e.g., the Samarga and Botchi),
large expenses of spruce-fir were included in the census area.
Along the Sikhote-Alin periphery, where habitat fragmentation and
human impact is more common, the area of individual count units
was substantially smaller than those in remote taiga regions
(Figure 1). Most count units covered a section of a basin or
small river for 10-30 kilometers. Survey routes within count
units were determined on the basis of natural, topographic and
hydrological features. Survey routes were selected to increase
the probability of encountering tiger tracks: tiger movements are
characterized by a generally well defined pattern in relation to
topographic and hydrological features (riverbeds, terraces, base
of slopes, mountain ridges) that serve as orientation points
(Matyushkin 1977). Routes most preferred by tigers, especially in
deep snow, are forest roads and snowmobile trails.
In winter, nearly the entire range of Amur tigers is usually
snow-covered. However, there may be considerable differences in
height and state of snow cover between regions. In the 1995-1996
winter snow cover was complete in most of the region by December.
By the time of the simultaneous census (see below), snow depth
ranged from 40 to 60 cm in valleys on the western macroslope of
middle Sikhote-Alin, and 15-25 cm in the southeastern Sikhote-
Alin (e.g. Lazovsky Zapovednik), although a narrow strip of
coastline remained partially free of snow. During and immediately
preceding the simultaneous census, there was no snowfall
sufficient to cover tiger tracks in any region of the census. In
general, snow conditions were favorable for the census work,
except in southwestern Primorye, where complete, lasting snow
cover never occurred.
3. METHODS
The Amur tiger census was conducted in the winter of 1995-1996 on
all potential habitat, as delineated from previous censuses in
the Sikh ate-Ann Range (Primorsky and Khabarovsky Krais) and in
the spurs of the eastern Manchurian Mountains (southwest
Primorsky Krai). The entire territory was spht into 8 regions
based on administrative boundaries of Raions (districts or
counties) - one "raion group" in Khabarovsky Krai and seven in
Primorye (Table 2). One specialist was designated coordinator for
each raion group. This division of the study area greatly
facilitated organisation and analysis of material, and provided a
basis for analysis of geographical differences in characteristics
of the tiger population (e.g., density, reproduction), conditions
of tiger habitat, and for developing conservation
recommendations.
Coordinators were responsible for the following raions:
PRIMORSKY KRAI:
Pikunov -- Pozharsky, Krasnoarmeisky (excluding tile Amm
Basin), Pogranicluly, Ussllriysky (the western
half)* Nadezildulsky (basins west of the Razdolnaya
River), Khasansky (the northern part, inclusive of
the Amba Basin);
Nikolaev -- Dalnerechensky, Kirovsky, Lesozavodsky,
Yakovievsky;
Yudin -- Spassky, Chemigovsky,
Abramov -- Anuchinsky, Mikhailovsky, Ussurisky (eastern part),
Shkotovsky, and vicinity of Vladivostok;
Salkina -- Chuguevsky, Lazovsky, Partizansky;
Bazylnikov -- Kavalerovsky, Olginsky;
Smirnov -- Temeisky, Krasnoarmeisky (the Armu basin),
Dalnegorsky;
Korkishko -- Khasansky.
KHABAROVSKY KRAI:
Dunishenko -- Bikinsky, Vyazemsky, Laze, Komsomolsky, Nanaisky,
Sovgavansky, Khabarovsky.
The study area was split into 652 count units (516 in Primorsky
Krai, 136 in Khabarovsky Krai) (Figure 1). Within each count unit
designated field workers were responsible for recording data on
presence/absence of tigers, measuring track size, directional
movement of tigers, date of occurrence, and providing first
estimates of sex and age.
Coordinators and regional hunting specialists selected field
workers based on their experience in count units, and their
specific knowledge about tiger habitat and movement patterns of
tigers within individual count units. The majority of field
workers were either professional hunters, zapovednik forest
technicians, or rangers working at zakazniks (wildlife refuges),
trade hunting or sport hunting units: thus, most field workers
had already worked within a count unit for many years. In total,
655 field workers were involved in the census.
The area of count units ranged in size from 20,000 to 60,000 ha,
depending on the estimated number of tigers within a general
region, the pattern of tiger distribution, forest types, forest
fragmentation, density of wild ungulates, density of roads, and
snow conditions. As a result, the potential for fully covering
count units varied.
A field "diary" was provided for each count unit and each
coordinator or regional specialist provided instructions for each
field worker, who at the same time signed a contract to conduct
the work. The field diary contained detailed instructions on
procedures and data sheets for collecting and reporting data of
the following types: all occurrences of tiger tracks, track size,
perceived changes in number of tigers compared to previous years,
any information on tiger deaths over the last 10 years,
information on past and present occurrences of tigresses with
cubs on the count unit, ungulate numbers (based on track counts,
and the field counters assessment of numbers), occurrences of
kills made by tigers on wild prey, and occurrences of tiger
depredation on domestic animals. Additionally, several questions
were asked to assess the attitude of field workers towards
tigers. Information on tigers was collected in field diaries as
two separate count periods:
1. All-winter track count: from November (beginning with the
first snow fall) to February, and, in some cases, until March,
2. Simultaneous census: conducted during February 10-12, 1996.
The timing for the simultaneous census was selected to coincide
with simultaneous counts of earlier censuses (in 1979 and 1985).
Census routes during the simultaneous census were no less than 25
km in each count unit, and were delineated to include all places
within the count unit where tiger tracks had been encountered in
the previous months.
Tiger tracks on count units were recorded both on diary data
sheets and maps (scale 1:100,000) with a unique track number,
estimated date of passage by the animal, width of the pad on the
front paw, estimate of sex, and presence of cubs (and their pad
width). The all- winter count and the simultaneous census were
reported separately.
Regional coordinators organized and summarized data from field
worker diaries in the following man or
- a summary map (scale 1:100,000) was prepared for all tiger
tracks encountered during the simultaneous census of February
10-12;
- an analogous map was developed for tracks reported from the
all-winter data set,
- based on these maps, identification of individuals was based
on: a comparison of track sizes and individual characteristics;
probable or exact information on date a track was created,
existing data on potential 24-hour travel distances of different
sex and age classes, determined from winter tracking (Yudakov and
Nikolaev 1987), and values of average linear daily travel
distances and diameter athome ranges, according to the results of
radio-tracking (MiqueUe and Smirnov unpublished). For mapping
general locations of individuals, a larger scale map (1:500,000)
was used.
To better organize original material for estimating tiger
numbers, the simultaneous and the all-winter counts were compiled
separately, and the all-winter database was additionally
separated into two periods: "November - December and
January-March. These 3 data sets were analyzed in the following
order: simultaneous census, all winter track registration in
January- March, and finally, all-winter track registration from
November-December.
All individual tigers delineated on the basis of track criteria
were divided into 2 reliability classes: positive and
questionable delineation (when delineation criteria were at their
maximum values or when there was unreliable information in the
field data, it was unclear whether some sets of tracks
represented new animals). Use of the criteria was not always
rigid. On occasion an evaluation of the available information was
based on the field experience of the coordinator. Identification
of individuals was especially problematic at boundaries of raion
groups, where there was a risk of double counting tigers that
used both sides. To avoid the potential for over counting, all
the original data along boundaries were analyzed jointly by
coordinators of adjacent raions.
In summarizing results, two rigid sets of criteria for
identification of individuals were developed based on the track
registration data: "soft" (criteria boundaries were smaller,
resulting in larger count estimates) and "hard" (criteria
boundaries were larger, resulting in smaller count estimates).
These criteria provided a control that effectively limited
subjective decisions on identifying individuals Use of these
criteria gave assuring results. However, in consideration of the
fact that original material was quite heterogeneous, we chose to
confine ourselves to the traditional data processing method, and
to conduct a detailed analysis in the
future.
The area of suitable tiger habitat was calculated by each
coordinator for his/her census region using existing material.
The following land formations were not included as tiger habitat:
settlements, non-forested sections, swamps, high elevation alpine
communities, spruce-fir forests or bums on former spruce-fir
forests, and areas with excessively deep snow cover in winter
(above 100 cm) which effectively excludes tigers.
The area inhabited by tigers was calculated by summing the area
of count units where tiger tracks were encountered during the
all-winter or simultaneous census. The relative density of tiger
tracks per 10 km of census route (Fig. 3 and 4) and individuals
per 1000 km* of suitable habitat in administrative raions was
determined (Fig. 6* Table 4). Relative track density provides an
estimate of tiger distribution without relying on an estimate of
tigers numbers.
Data from the all-winter count and simultaneous census were
summed by administrative raions (Tables 3 and 4), by raion
groups, and for Primorsky and Khabarovsky Krais (Table 5).
Determination of track distribution along the periphery of tiger
territory provided the basis for delineating distribution
boundaries of Amur tigers in the winter of 1995-1996 (Figures 2
and 3).
Delineating the sex-age structure of the tiger population was
based on measurements of track size. There is a considerable
database for estimating sex of tigers from track sizes, based on
measurements of the width of main pad of the front paw of known
sex and age tigers. Besides information from zoos (Matyushkin and
Yudakov 1974), there are data on tigers in the wild that died or
were killed in nature (Nikolaev and Yudin 1993), and also on
animals captured and radio-collared (Miquelle and Smirnov
unpublished). Thanks to help of Ms. S. Christie, EEP Tiger
Coordinator, this year we obtained additional track size data
from captive tigers. Data from 130 tigers of determined sex and
age confirm previous assessments (Matyushkin and Yudakov, 1974).
We summarize the main points here.
With very few exceptions, tracks with pad width equal or
exceeding 10.5 cm represent males. Tracks ranging in size from 8
to 10.5 cm include both adult (and subadult) tigresses and
subadult males, although females are the predominant sex in this
category. "Many zoo- raised males exceed 10.5 cm in their second
year, similar measurements have been made on young males still
traveling in a family group in the wild (Miquellle and Smirnov
unpublished). In general, pad size stabilizes when males reach
3-4 years of age. Identification of tigresses is reliable when
smaller tracks (representing cubs) are found in association with
them, and in these cases, all measurements of tigress pad width
are within the 8 to 10 cm range. Track measurements of cubs in
association with mothers in winter usually range in size from 6.5
to 8 cm, but as already noted, can reach 10.5 cm.
Because of the difficulties in differentiating sex of animals by
track size, a considerable percentage of animals are recorded as
unknown sex (Table 6). Accordingly, assessment of the sex ratio
of the Amur tiger population from available census data should be
made cautiously.
Litter size dynamics were analyzed using material from both the
present census and reports of field workers who recorded presence
of litters on their count unit between 1989- 1996. With this data
we attempted to assess changes in litter size associated with
geographic variation, yearly variation, and variation over the
winter.
All field workers were requested to report information on tiger
deaths in their field diaries. Additional information was
acquired verbally by questioning field counters, employees of
state hunting management services and local villagers. These data
were used to compare the extent of poaching activity for the
periods 1985 to 1990 and 1991 to 1996, when available evidence
suggested a surge in poaching due to new opportunities to sell
tiger products.
Tiger population density (Figure 6) and location of identified
individuals throughout Primorsky and Khabarovsky Krais (Figure 5)
were first mapped by each specialist for his/her region, and
subsequently generalized by krai coordinators. Tiger distribution
maps (Figures 5 and 6) include the number of positively
identified individuals only.
The summary map of tiger distribution in the Russian Far-East
(Figure 5) represents the collective effort of all coordinators,
who rolled on the reports of field workers, but also used their
knowledge of the region and their experience gained during
research on Amur tigers. The technique of data collection and
analysis used in the present census was generally similar to
those used in previously censuses (particularly, the last three
censuses). Similarity in methodology allows us to compare
results, and assess long-term trends in the dynamics of the Amur
tiger population.
4. RESULTS
4.1 NUMBER AND DISTRIBUTION OF TIGERS IN THE RUSSIAN FAR EAST
PRIMORSKY KRAI
Results of the census confirmed that in addition to the main
population of tigers in the Silkhote-Alin Mountain Range, tigers
occur in two small, isolated habitat fragments near the Chinese
border in the West and Southwest regions of Primorsky Krai
(Figures 2 and 5).
WESTERN RAION GROUP. This fragment of habitat includes parts of
Pogranichny and Khankaisky Raions in Primorsky Krai. Suitable
tiger habitat comprises less than 240,000- 250,000 ha. It is
divided from the Sikhote-Alin population by extensive
non-forested Prikhankaiskaya lowlands, and from the Southwestern
habitat fragment by non-forested and agricultural lands of the
Razdolnaya River Basin.
Tigers have been rare in this habitat fragment for at least 30-40
years. No more than 4 individuals were found in this area in 1970
(Yudakov and Nikolaev 1973), no tigers tracks were found in
1978-1979 (Pikunov et al. 1983) and tigers were apparently absent
almost to the end of the 1980's. Tigers reappeared again at the
beginning of the 1990's, but there was likely never more than 4-6
individuals. High and stable number of ungulates, especially of
wild boar, has not resulted in an increase of this
"micropopulation" probably due to intensive tiger poaching,
typical for such hunting units where intensive sport hunting of
ungulates occurs. The range of all tigers using this region no
doubt extends into China despite the existence of a fenced
boundary along the Russian Border Protection Zone. Tiger poaching
is likely occurring in China as well as Russia.
It has been speculated that this Western population of tigers may
retain contact with the Southwestern population through the
territory of Heilongliang Province, China. However, contact seems
unlikely due to a high human population in this territory and the
absence of suitable tiger habitat.
Apparently tigers periodically disperse in the Western habitat
fragment by passing through the Prikhankaiskaya lowlands (such
occurrences have been reported), or via Ussuriysky and Oktyabrsky
Raions of Primorsky Krai by following the country border. The
second route seems more likely. Considering the complexities of
current natural resource utilization polcies, and the current
state of environmental protection organizations, the likelihood
of an increase in the number of tigers in the western habitat
fragment is low.
For the entire winter period of 1995-1996 tiger tracks were
located near the Chinese border in the upper basin of the Right
Komissarovka River. Two adult individuals appeared here at
different times: a male tiger with pad width of 10.5 cm, and a
female (9.0 cm) with two cubs (8.5 and 8.0 cm.) that wandered
independently. All four individuals periodically crossed the
country border into China.
SOUTHWESTERN RAION GROUP. The area of suitable tiger habitat in
this region is 350- 400,000 ha. Movement of individuals between
this region and Sikhote-Aim are likely to occur through the area
between Teryokhovka and Baranovsky villages, where spurs of the
Sikhote-Alin Mountains closely approach the eastern edge of
Borisovskoe Plateau. The number of tigers in this region has
varied from 2 -3 individuals in 1970 to 14 in 1985, including
individuals that range hack and forth between China and Russia.
In the southern part of this region a narrow band of habitat,
surrounded by non-forested lands and the coastline of the Sea of
Japan, forces most tigers to range on both sides of the
international border. The upper reaches of river basins and the
whole western part of the region is presently the best available
habitat because it is protected by the border patrol guards. Due
to strategic location and special status, these regions contain
well-protected black fir-Korean pine-broadleaved forests, high
and stable numbers of wild ungulates, a low density road network
and in general a low level of disturbance. The best potential for
protecting tiger habitat occurs on the Borisovskoe Plateau
Zakaznik, Barsovy Zakaznik and Kedrovaya Pad Zapovednik.
Presently, the ungulates of this region are under intensive
hunting pressure from the residents of Vladivostok and Ussurisk.
Suppression of tiger numbers is most likely due to poaching and
official shooting of tigers causing depredation problems at deer
farms. A minimum of 5 individuals were counted within Khasansky
Raion in the winter of 1995-1996: 2 males, I tigress with a cub
and I individual of undetermined sex. Tracks of the latter were
registered from the Barabashevka middle drainage to the Amba and
Gryazllaya Rivers by two adjacent coordinators. One male tiger
was reported in Nadezhdinsky Raion, tracks most often appearing
in the Gomaya Basin and on the right bank of the Borisovka River.
It's quite possible that this male, as well as the two inhabiting
southern Khasansky Raion, travel between Russia and China. The
presence of a single individual of undetermined sex was observed
in the western half of Ussuriysky Raion (in the Krounovka Basin).
In summary, the maximum number of individuals identified in the
Southwestern Raion Group was: 3 adult males, 3 females (one of
which had one cub), and 2 individuals of undetermined sex, for a
total of 8 individuals (7 adults and I young).
The rest of the raion groups included in the winter census of
1995-1996 are situated within the Sikhote-Alin Mountain Range.
Each of these regions are examined separately.
NORTHWESTERN RAION GROUP. This region includes the western
Sikhote-Aim macroslope in the northern and central regions of
Primorsky Krai. This isolated and sparsely populated territory
retains relatively intact Korean pine-broadleaved forests, and
for the last 25 years has been considered one of the best remain
blocks of tiger habitat. In the past, 20-300/0 of the Sikhote-Aim
tiger population inhabited this region.
In the 1970 census the maximum number of tigers was reported in
the Malinovka (Vaku) and middle Big Ussurka (lman) Basins. As
intensive development of this region proceeded, the core region
of this population shifted to the north and was concentrated in
the Bikin River Basin in the 1980's and 90's. The results of the
1979 and 1985 censuses indicated that the density of tigers in
this region was exceeded only by Sikhote-Aim and Lazovsky
Zapovedniks. Results of the present census also demonstrated that
the middle and upper portions of the Malinovka Basins retain a
very high number of tigers, similar to that found in the 1970's.
This raion group occupies 59,355 km/2, but suitable tiger habitat
occurs only on approximately 80% of the region (48,268 km*)
(Table 5). Besides non-forested lands, high elevation spruce-fir,
small-leaved deciduous, and larch forests near the crest of the
Sikhote- Alin Mountains hold deep snows that effectively limits
use by tigers in winter.
Suitable tiger habitat in the raion group was divided into 199
count units (averaging 26,700 ha) that were the basis for
gathering information on tigers in the region. Permanent snow
cover was complete by the beginning of November, and by the time
of the simultaneous census (February I0-12), snow depths had
reached 30-40 cm or more throughout most of the territory.
On the one hand, heavy snow made the census easier because in
deep snow tigers prefer to move on frozen rivers and creeks,
roads, sled trails and paths where travel is easier. On the other
hand, chances of not counting individuals that remain for long
periods within a small territory increase. However, the risk of a
poor count is not that high in this raion group, as most field
workers were local residents with extensive experience working in
the taiga.
The total number of tigers in the Northwestern Raion Group was
estimated at 108-133 individuals (Tables 4 and 5), including
32-35 males, 36-46 females, 20 individuals of undetermined sex
and age, and 20-32 cubs. Average population density was 2.6-2.7
individuals/LOCO km/2, with a maximum of 4.7 individuals /1000
km/2 in the Malinovka, Kabarga, Kedrovka, Zolotaya, and upper
Okhotnichya Basins (Table 4). A decrease in tiger numbers in the
region probably began in the early I990's. The status of the prey
base throughout this region is generally poor, and can be
considered critical in the number of places. In some
places densities of wild boar and elk has decreased drastically.
The following general tendencies were noted in the Raion Group:
1. In comparison to 1979 and 1985, the number of litters has
decreased. For example, in the middle and upper Bikin Basin
previous censuses indicated 5-7 tigresses with litters, but the
1995-1996 census revealed only three tigresses with cubs in the
same region at the beginning of the winter. By the end of January
and during the simultaneous count, no tracks of litters were
encountered, and their fate remained unknown.
2. The population decreased slightly in the central portion of
the territory along the central basins, with a relative increase
in the upper reaches of basins. This change was probably
associated with a decrease in the number of wild boar, worsening
of habitat quality, and greater frequency of tiger poaching near
settlements.
3. On the whole, the number and density of this subpopulation is
close to the 1985 level. Intensified poaching and increasing
frequency of conflicts between tigers and humans has probably
prevented any potential increase in tiger numbers. Conditions for
tigers are worsening especially in the more populated western
part of this region, where ungulate numbers decreased to very low
levels after the extremely snowy winter of 1994-1995.
SOUTHERN RAION GROUP. This raion group includes the southern and
southwestern Sikhote-Aim Mountains, and Ussurisky Zapovednik.
Within existing tiger range this region is under the most
pressure. This is the most heavily populated area of the Russian
Far East, and consequently, high levels of disturbance, low and
unstable numbers of ungulates, and systematic official and
unofficial hunting of tigers has put a constant strain on the
tiger population. Habitat conditions for tigers are
deteriorating. Liquidation of former infrastructures controlling
use of natural resources, and the recent collapse of a legal J*
framework for managing hunting units, has resulted in decreased
protection of wildlife and of all natural resources, including
the tiger. This situation is typical over the entire range of
tigers, but especially critical in this raion group.
Suitable tiger habitat was divided into 112 count units covering
941,000 ha of suitable tiger habitat. A total of 70-79 tigers was
counted in this region, including: 19-23 males, 21- 26 females,
11 cubs, and 19 animals of undetermined sex (Tables 4 and 5).
Regional coordinators and their assistants believe the tiger
population in this raion group is currently in a "depressed"
condition: a small percentage of the females were with litters,
which usually consisted of only one cub, while at the same time a
high percentage of the population is adult males. This situation
appears to be due to an insufficient prey base (ungulate
densities are low here) and shooting of tigers. Ussurisky
Zapovedluk has a well preserved natural ecosystem, but it is a
very small area (40,432 ha). Nonetheless, there is a
concentration of tigers here because it is the only remaining
reserve in the raion group. In the last 5-7 years there has been
significant decreases in tiger habitat and tiger numbers. If the
present trend continues* in 4-5 years tigers will be a rarity in
the southern Sikhote-Ann region.
NORTHEASTERN RAION GROUP. This region includes Sikhote-Alin
Zapovednik, which perhaps represents the best remaining habitat
within the present range of the Amur tiger. This conclusion is
confirmed by all censuses, including this one, conducted in the
Russian Far East.
The census results are as follows. Approximately 75% of Temeisky
Raion was surveyed. Relatively large "blank spots** occurred in
the upper reaches of Samarga, Maximovka and Velikaya Kema River
basins. The same situation was common in Krasnoarmeisky Raion
where approximately 3000 km* of the Upper Arma was not surveyed.
However, according to all available information and reports of
local hunters, sign of tigers is rarely observed in this region.
There were considerable difficulties in organizing the census in
Dalnegorsky Raion, and consequently, only the simultaneous census
was conducted on most of this territory. Due to the high human
density, well developed industrial complex, dense network of
roads, high logging activity (and a resulting low density of
ungulates), there were few tigers reported in this region.
Difficulties in organization are probably similar to those
observed throughout Primorsky Krai, and are largely related to
the dissolution of the wildlife management structure (upon which
earlier censuses were based).
The simultaneous count was conducted in all 92 count units in
this raion group, and the all-winter count was conducted in 85 of
those units. Approximately 80% of the raion group was surveyed.
Weather conditions were good for the census: snow cover averaged
15-20 cm in the southern part of the region and 50-60 cm in the
northern and upper portions of the river basins.
Sex and age structure of the 86-98 tigers counted in this raion
group was: 13-17 males, 22-26 females, 32 individuals of
undetermined sex, and 19-23 cubs (Tables 4, 5, and 6).
In general, the tiger population in this raion group appears to
be on the rise: in the south the density has stabilized and a
steady increase is being observed in the north. The region can be
ostensibly divided into two parts: the Zapovednik and adjacent
territories, and other regions. The Zapovednik and adjacent
territories are well-protected lands with high ungulate
densities, and consequently more than half of all tigers counted
use this area, even though it comprises less than 30% of the
raion group. Outside the Zapovednik and adjacent areas, where
there is presently little protection, the existence of tigers can
only be attributed to the low human population inhabiting the
taiga. There exist several serious threats to the future
conservation of the tiger in the region. Two such threats for
tiger survival are the plans for development of the
Sukpai-Agzu-Nelma road (opening up one of the last unlogged river
basins, the Samarga, to exploitation) and the activity of the
joint Russian-Korean logging enterprise "Hyundai" in Svetlaya.
The Svetlaya port has become an open market for exporting tiger
products to Korea and China.
SOUTHEASTERN RAION GROUP. This region, including Lazovsky
zapovednik plays a very important role in tiger conservation, as
indicated by the results of the present and three previous
censuses. Density of tigers is similar to that observed in the
Northwest and Northeast Raion Groups, and Lazovsky State
Zapovednik represents some of the best available habitat,
comparable to Sikhote-Ann Zapovednik and the middle Bikin Basin.
Habitat conditions here are especially favorable for tigers,
although this region is more highly developed and densely
populated than the raion groups to the north. Since the early
1970's there has been a consistent increase in tiger numbers,
especially in the Zapovednik and adjacent territories.
Population growth probably proceeded into the early 1990's. With
the dramatic increase in tiger poaching (beginning in the early
1990's), tiger numbers have decreased throughout the Southeast
except within the Zapovednik.
Results of 1995-1996 census indicated 80-82 tigers in this raion
group: 21-22 males, 23-24 females, 23 cubs, and 18 tigers of
undetermined sex (Tables 4, 5, and 6). Tiger distribution in the
southeast is not even. Maximum population density (5-7
individuals / I000 km/2) exists within Lazovsky Zapovednik and
adjacent territories, in unprotected areas, density ranged from 2
to 4 individuals / 1000 km/2. A decrease in ungulate numbers has
been noticed throughout the entire raion group except within the
Zapovedluk. The abundance of tiger prey is probably inadequate,
although the region differs from the others in that there exists
relatively high numbers of deer and goral.
The status of the tiger population in the Southeast is adequate,
although the majority of field workers noted a decrease in tiger
numbers since 1989-1990. All available habitat appears to be
filled, so that population numbers are regulated by both trophic
factors and intensive poaching.
KHABAROVSKY KRAI
Northern Raton Group. A minimum of 64 tigers was estimated to
reside in Khabarovsk Krai in the winter of 1995-1996, including 8
cubs (6 litters) and 8 young animals that were categorized as
cubs based on the standardized criteria. It is likely that only 3
of these 8 young animals were in reality cubs: the other 5 were
likely individuals of undetermined sex, whose small track size
were actually measurement errors. Additionally, 4 adult
individuals and one adult female with two cubs were classified as
questionable. Among them was a female that used the Upper Gorbun
Basin (Bikinsky Raion) and may also have used adjacent Primorye
basins (and thus be counted twice), females in units 21-47
(Podhoryonok-Matai) were identified as two different individuals
based on the criteria (they may have been one animal), two
individuals of undetermined sex using units 98-99 (Nelta-Moken);
and a male in unit #85 (Matai, Ivanov Creek).
Several mistakes may have been made during the collection and
processing of information. Reports of two females with cubs at
Sol most likely represent two lynxes that passed along tiger
tracks, a female in the Upper Gorbun is likely animal #3 from
count unit #9, and the other animals either traveled widely or
were incorrectly located on maps. Despite these potential errors,
the maximum count in the winter of 1995-1996 is no more than 71
individuals. It is preferable to use the minimum value, 64
individuals, as a more conservative estimate.
Population density averaged 1.6 individuals per 1000 km* (Table
5). Density was at a minimum on the periphery of tiger range and
practically equal elsewhere, if Khabarovsky Raion - where tigers
live in an isolated habitat fragment on the Big Khekhtsir Range -
is not included. Tigers in the Big Khekhtsir Range and adjacent
regions are probably unimportant as they are likely to soon
disappear. According to archival material, animals had been
absent in this territory since 1937, yet appeared again after
more than 50 years. At the time of the census, the area inhabited
by tigers in Khabarovsky Krai was 33,633 km/2, representing 61%
of potentially suitable tiger habitat (55,000 km*). The term
"suitable" tiger habitat is difficult to define in Khabarovsky
Krai as because tigers presently inhabit some forested regions
where the species was absent at the end of tile 1980's, a time
when tile tiger population was at a maximum.
The second indicator, area presently inhabited by tigers, is more
suitable for analysis. In comparison to data from 1993-1994, the
distribution of tigers in the southern part of the Krai has
contracted 20.4%, in Komsomolsky Raion 47.60/0, and in
Sovgavansky Raion only 13.7% (either the population increase
continued longer here or coverage of this raion was insufficient
in the 1993-1994 census). In Nanaisky Raion and Raion imeni Lazo,
the decrease in distribution is probably seasonal, and caused by
deep snows in the mountains. In these two raions, no major
changes in the range of tigers was noted, except for habitat
contraction in the already fragmented Sukpai Basin. However,
habitat losses were quite obvious in Vyazemsky and Bikinsky
Raions, where tigers abandoned development sites along the
mountain bases. Consequently, the range boundary has shifted to
the east. In Kollasomolsky Raion the same kind of development has
contracted the range boundary to the south. These changes may be
a result of stabilizing numbers and a tendency for decrease in
numbers at the center of the range. It is likely that tiger
distribution will continue to shrink in the future.
Based on the fact that there has been a considerable decrease in
cattle depredation, the number of tigers entering settlements,
and the number of pandering" tigers (animals without a permanent
home range), it can be concluded that the number of tigers is
close to being balanced with the density of prey populations,
with a slight predominance of predators. The present situation
also suggests that, when the tiger population reached a maximum
(1987- 1990), there were likely 90-100 individuals in Khabarovsky
Krai, and density throughout much of the range was practically
the same: 2.2-2.4 individuals / 1000 km/2. However, in the
central part of the range tiger density was likely twice these
estimates. We can estimate the potential number of tigers in
Khabarovsk Krai with an extrapolation based on the present-day
area of suitable habitat and average density of tigers. This
estimate, 120-130 animals, is approximately 2.5 times less than
the number estimated for the middle of the 19th century, and
approximately twice more than the present census indicated.
It should be noted that not all 64 tigers occurred only within
the territory of Khabarovsky Krai. In Bikinsky, Vyazemsky Raions
and in Raion imeni Lazo, 8-10 animals commonly ranged into
Primorsky Krai. Movements are most typical in the first half of
winter before deep snows cover mountain passes. Therefore, in
November there is typically an "invasion" of predators. Wandering
and dispersing tigers arrive from the Bikin, Samarga, and Edinka
Basins. This pattern was especially noticeable when the tiger
population was increasing, and new animals appeared through
ecological corridors near Podhoryonok, Matei, and Katan. It was
probably these animals that ended up in Solontsovy, Shumniy,
Vyazemsky and a number of other smaller villages. If there is a
dramatic decrease in tiger numbers, a reverse process may be
predicted, that is, a shrinking of tiger range in towards optimal
habitat.
The sex-age structure of the population in Khabarovsk Krai group
was: 20 males (31.2%), 17 females (26.50/0) (including 6 females
with cubs - 9.4%),11 adult and subadult individuals of
undetermined sex (17.2%),16 cubs (25.0%) (including 8 cubs still
with tigresses - 12.50/0). These results are based on data
provided by field workers and subsequently checked by
coordinators with specific criteria. Assessment of sex and age
structure with this kind of data is difficult, and there is the
potential for many errors. Nevertheless, the sex ratio of the
adult population indicating a majority of males (1:1.18) is
consistent with the results of our analysis on sex composition of
litters during a period of low numbers, beginning in the 1960's,
also indicating a predominance of males (1:1.2). The number of
cubs determined to be traveling without females is unlikely. As
mentioned above, this number is not likely to exceed 3
individuals according to verifiable data. If we make such an
adjustment in the data, there would be 5 less cubs, and 5 more
animals of undetermined sex. Consequently, cubs would comprise
17.2% of the population, instead of 25%. The category
"individuals of undetermined sex" includes both young males and
subadult females. If we assume that the average percentage of
cubs in the population has been no more than 20% for the last two
years, then on the whole young animals of undetermined sex should
represent about 30% (19- 21 individuals) of the population,
taking into account mortality.
Thus, the territory of Khabarovsk Krai was inhabited by 45-50
adult tigers at the end of the 1996 winter, including 20-23
mature females. Consequently, tigresses with litters comprised
26-30% of the population. The average litter size was 1.33
cubs/adult female by the end of the winter. According to these
calculations, reproductive output in the last year was far below
the potential. It appears that in the last three years
reproduction approximately equaled mortality; consequently
population growth is likely only in the areas with especially
favorable conditions.
In summary, results of the 1995-1996 winter census of Amur tigers
in the Russian Far- East indicated the following:
males 108-121;
females 132-143 (52-58 with cubs),
undetermined sex 90-107;
cubs 85-105,
and a total of 415-476 Amur tigers within the Russian Far East.
A breakdown for each of the Krais indicates the following:
in PRIMORSKY KRAI:
adult tigers (includes subadults) 282 - 318
cubs 69 - 87
total number in Primorye Krai 351 - 405
in KHABAROVSKY KRAI:
adult tigers (includes subadults) 48 - 53
cubs 16 - 18
total number in Khabarovsky Krai 64 - 71
TOTAL POPULATION OF ADULTS AND SUBADULTS 330 - 371
TOTAL POPULATION OF ADULTS, SUBADULTS AND CUBS 415 - 476
Data on the sex-age structure of the population is presented in
Table 6 by raion and raion groups. Population density was
calculated for the adult segment of the population, including
individuals of undetermined sex and age. Maximum adult tiger
density estimates (including animals "questionably identified")
were calculated for in Tables 4 and 5, but minimum density
estimates (without questionably identified" individuals) are used
in Figure 6.
4.2 ANALYSIS OF DATA ON LITTER SIZE
Information on 528 litters of tigers over the last 12 years was
reported in field diaries by field workers (mostly hunters) and
wildlife management specialists who personally saw tracks of
females with cubs in their hunting sections. Because the data is
based on personal observations we be believe it is fairly
reliable. It is likely that many litters were reported by several
people. However, we were able to conduct a "retrospective"
analysis, which, while it may not be extremely accurate,
nonetheless can act as an indicator of geographic variation and
dynamics of Amur tiger reproductive parameters (Table 7). The
data allow us to compare trends in reproduction performance of
the population on the periphery of the range and in the center of
the subspecies distribution. Average litter size across raion
groups varies by as much as 22% (Table 7). Lower productivity in
the southern part of the range may be one reason why there has
been a decrease in numbers in such raions as Mikhailovsky,
Chuguevsky, Anuchinsky, and Shkotovsky, where, 10-15 years ago,
density was the highest.
Analysis of geographic variation in reproduction indicates
regions of high productivity, and provides an indicator for
prioritizing areas needing protection. Average litter size was
largest in the Southeastern Raion Group of Olginsky, Partizansky,
and Lazovsky Raions, in the Northeastern Group in Temeisky Raion,
and in the Northwestern Group including Dalnerechensky,
Kjasnoarmeisky, and Pozharsky Raions. Based on litter size it is
determined that the best "tiger" raions in 1996 were Olginsky,
Partizansky, and Dalnerechensky. In other words, within each
raion group there is a pattern similar to that observed over the
entire range* a decrease in reproductive output from the center
to the periphery of a region. This fact can be clearly
demonstrated by looking at litter size in each raion of the large
Northwestern Raion Group: Pozharsky - 1.77, Krasnoarmeisky -
1.80; Dalnerechensky - 1.94; Lesozavodsky - 1.8, Kirovsky - 1.78,
and Yakovievsky - 1.67. This variation can be explained by
geographic variation in habitat quahty: in the higher mountains
there is more snow and fewer prey, while in the lower reaches of
basins human disturbance is greater. The middle sections of river
basins represent the **golden center". These regions are
responsible for producing the majority of young, but
unfortunately, such **reproduction centers" are contracting in
size.
An analysis of changes in tiger litter sizes over years (Table 8)
suggests that, since 1993, there has been a steady decrease in
the reproductive rate, on average, by 8.8%. It is interesting to
note that the number of elk and wild boar in Khabarovsky Krai is
also decreasing at approximately the same rate. We can use this
data to predict that litter size will likely decrease to an even
smaller average size in 1996-1997. An increase in the number of
wild boar and a stabilization of the elk population at low levels
in the coming 2-3 years could be a stimulus for tiger
reproduction (or for an increase in survival), but it is not
likely to result in an increase in population size. After this
period, there is a high probability that insufficient food
resources will result in increased depredations by tigers, and a
greater threat to human life, thus forcing an increase in
official shootings.
The average litter size of Amur tigers in winter was 1.66-1.7
cubs. More than half of all females (52%) have 2 cubs, even in
winter when some mortality has already occurred (Table 7).
According to our long-term observations, annual loss of cubs
ranges from 16.0 to 26.4%. The higher mortality estimate was
based on data obtained in Khabarovsk in 1994, when 18 of 34 cubs
died over a two year period. Presently, litter size (at birth) is
estimated at 2 to 2.3 cubs, but only slightly more than one
individual reaches the age of sexual maturity. An attempt to
track changes in litter size through the winter (Table 9) does
not provide a clear picture due to the insufficient number of
observations in October, March, and April, when there is no snow
and few hunters in the taiga. If data for November and February
are representative, the results indicate a tendency for litter
size to decrease approximately by 6.80/0. These results, and
additional data from Khabarovski Krai, indicate that no less than
15% of cubs are lost in winter.
Monitoring litter size provides important information for
understanding the dynamics of reproduction in the Amur tiger
population, and for predicting changes in population size.
Moreover, this type of information is considerably easier to
obtain than a complete census.
Information provided by zoos and publications indicate that the
sex ratio of cubs is close to 1:1 at birth. Data based on capture
of 142 cubs in the wild confirms that on average equal numbers of
males and females are born in the wild. However, sex ratios
change over time: female cubs were more common up until 1947
(1:0.67), from 1947 to 1970 males were the majority (1:1.5), and
from 1975 to 1989, during a period of rapid population growth,
females dominated again (1:0.65 - 20 females and 13 males out of
43 captured animals). Since 1990- males were again more common
(1:1.2). This information is especially important for
understanding mechanisms of change in tiger numbers and for
predicting future trends. Periodic increase in the female
proportion of the population, a reduction in age at first
breeding, (noted, for instance, by various scientists at the end
of the 1980s), and an increase in litter size are the three
factors that can boost the reproductive rate and result in rapid
population growth. Apparently, population increase is also a
response to an increase in food resources and a "open niche".
Supporting evidence comes from the fact that the highest density
of wild boar occurred at the end of the 1960's. Elk numbers were
probably also at a maximum at this tune, or, in any case, no less
than 3 times as high as present numbers, based on comparisons at
permanent census plots in Khabarovsky Krai.
In the early 1990's, a natural decrease in tiger numbers
coincided with an unprecedented increase in poaching. Similar
scenarios are typical for virtually any species that is
commercially exploited. As more people become involved, the more
effective the exploitation becomes, but, as a rule, improvement
of hunter abilities, additional equipment, and use of special
capture equipment reach their highest level of intensity late,
when the animal population is already decreasing. Analogous
patterns associated with population peaks and decreases are well
known in predator-prey systems.
Judging by the present-day sex ratio and a natural decrease in
population growth rates, the tiger population is presently going
through a period of stabilization, with a negative growth rate
that is largely a result of decreasing habitat quality and
quantity, and on-going poaching.
4.3 DATA ON TIGER MORTALITY
By 1985 a major decrease in wild ungulate numbers occurred within
tiger range due to a series of hard winters. At the same time,
conflicts with human beings, depredation on domestic animals and
at deer farms, and tiger incursions into villages became more
frequent. As a consequence, the number of official and
non-official shootings has increased (Table 10).
By the beginning of the 1990's ungulate numbers had increased or
stabilized in many raions. At the same time, that segment of the
tiger population that was accustomed to cattle depredation and
entering settlements had been largely removed. However, a new
threat developed, namely commercial poaching, which arose from
the new found possibility of selling tiger products abroad (pelts
and derivatives of tiger carcasses). Tiger bones and other parts
of the carcass have always been in high demand in many Asian
countries, where they are considered to be one of the most
valuable ingredients in traditional Asian (Tibetan) medicine.
Expanding international ties provided an easy avenue for moving
tiger products through Vladivostok and Khabarovsk.
The information presented in Table 10 is based on responses of
field workers to the question in the field diary: "Do you know
any cases of tiger deaths?". We believe this summary is far from
complete. More than 90% of the field workers did not answer the
question, or gave information that was already generally
well-known. According to other calculations, an average of 40 to
50-70 tigers could have been Idled annually (Pikunov 1994,
Nikolaev and Yudin 1993). This estimate, together with natural
losses, may exceed the reproductive potential of the population.
Considering the results of the present tiger census, the sex-age
structure of the population, its reproductive potential, and
comparison of the results with the previous census of 1984-1985,
it is likely that one of the main factors regulating tiger
numbers in Russia today is poaching caused by a great demand and
high prices of tiger products.
5. DISCUSSION OF RESULTS AND CONCLUSIONS
According to the results of 1995-1996 winter census, the range of
Amur tigers in the Russian Far East occupies an area of
approximately 156,500 km/2, including 123,000 km/2 in Primorsky
Krai, and 33,500 km/2 in Khabarovsky Krai: (Table 5, Figure 2).
It appears that animals inhabit nearly all forested lands within
the present range (at least periodically). Potential
fragmentation points of the population within the massive
Sikhote-Aim Range are not significant or are stable. Thus, for
the most part this territory has retained its integrity to date,
with the exception that at the northern limits of tiger range,
fragmentation of some localized subpopulations is occurring (in
the Sukpaiskaya, Samarginskaya, Botchinskaya regions) that could
result in complete isolation from neighboring subpopulations.
However, localized habitat fragments associated with small,
isolated mountain ranges -Samursky and Khekhtsirsky- separated
from the Sikhote-Aim, have already become **islands' (Table 11).
Isolation of the Western (Pogranichny) and Southwestern habitat
fragments from the main population is even more dramatic. Contact
between these isolated subpopulations with the main population in
Sikhote-Aim is possible by disperses and nomadic individuals that
are always present in the population. This category of animals
includes young animals starting an independent life, adult males,
and occasionally, even females with cubs. However, during the
period of the census, there were no resident individuals located
in potential contact zones between habitat fragments and the main
range.
The potential for range fragmentation is not yet a threat
throughout the greater portion of Sikhote-Ann. Though there
exists great ecological variation within this mountainous
landscape, the Amur tiger population still retains its integrity
as a single population. At the same time, fragmentation points
are appearing; one of which, near Svetlaya in Temeisky Raion,
threatens to separate the above-mentioned Samarginskaya
subpopulation. This danger is also very real for the
"Sinegorskaya* subpopulation in Spassky and Chemigovsky Raions of
Primorye, and for the Anyuiskoy subpopulation in Khabarovsky
Krai. If these small subpopulations ever become isolated, they
are likely to quickly disappear.
Tiger distribution in the Sikhote-Aim Mountain Range, as revealed
by the census, confirmed that highest densities occur on
zapovedniks (Sikhote-Aim, Lazovsky, and Ussurisky Reserves) and
areas adjacent to them (Figure 6). The same trend was noted in
previous censuses, but the difference was less dramatic. For
example, in the 1970-1980's large areas of (unprotected lands
were also considered high quality habitat (the middle Bikin
Basin, the Malinovka (Vaku), Ussuri and other river basins). The
growing discrepancy is likely caused primarily by poaching, and
secondarily by deteriorating habitat conditions on unprotected
lands. Degradation of tiger habitat, and a reduction of suitable
habitat for this species will inevitably continue. Despite this,
existent zapovedniks cannot guarantee survival of the Amur tiger
because their combined area is too small and disconnected. In
order to resolve this problem a network of large, interconnected
tiger preservations** must be established which includes
zapovedniks as core areas. A limited land-use regime would be
implemented over much of the reservation lands. Delineation of
large "protected zones" was proposed following the results of
1984-1985 census *Pikunov and Bragin 1985, Pikunov 1990). A more
relaxed, traditional land-use regime can be applied for
ecological corridors that link main reservations into one system.
At the same time, it is important to raise the prestige and
status of hunting (wildlife) management organizations, increase
ungulate densities on hunting territories, more strictly regulate
hunting, and forcefully suppress poaching.
The last detailed inventory of the tiger population in Primorsky
Krai (1984-1985) indicated that tigers occupied approximately
110,000 km/2. The slight increase in tiger range (to 123,000 km/2
in Primorye) reflects the range expansion in northern
Sikhote-Aim, into marginal tiger habitat, such as the Samarga
Basin, the Upper Bikin, Big Ussurka, Ussuri, etc. Possibly this
expansion occurred simultaneously with the decrease in tiger
densities in more typical regions along the central portions of
river basins. In regions newly colonized by tigers, heavy snow
winters typically result in a decline in their number, especially
if associated with a decline in previous years of the key prey
species - wild boar and elk.
Estimation of tiger numbers was based on a procedure which
included, as an essential component, the coordinator's knowledge
and experience of the peculiarities of tigers in each count unit.
In addition, as mentioned above, during data processing, and
prior to analysis, a new system of rigid criteria was developed
for identifying individual tigers This new system consisted of
two sets of criteria* "soft** and "hard" (which resulted,
respectively, in larger and smaller estimates of population
size). These criteria were based on an assessment of changes in
track parameters, 24-hour linear movements for males and females,
total home range size, and other measurements. The values for
these criteria was taken from published materials and unpublished
data from radio-tracking studies on tigers in Sikhote-Aim
Zapovednik. The criteria provided clear orientation points, and a
single methodology to assess census results by different
coordinators.
For the majority of coordinators, results of using the
traditional census technique to count tigers fell between the
ranges determined by the hard and soft criteria. However, within
zapovedniks, without exception coordinators* estimates exceeded
those based on the set of soft criteria. Obviously, an additional
assessment is required for complete uniformity of census results.
It is noteworthy that the ratio of tracks per positively
identified individual varied among coordinators: from 10-11
tracks (Pikunov, Nikolaev) to 6-7 tracks (Smirnov, Salkina).
Within regions assigned to each coordinator, usually 10 to 20% of
suitable tiger habitat was not covered by the census due to
variety of problems. Consequently, some underestimation of the
population likely occurred in these areas. However, it is very
likely that this error is compensated for by an overestimation in
several regions. Thus, these errors likely negate each other, and
do not greatly distort the results of the census.
A review of previous census data and other population estimates
suggest that the Amur tiger population was increasing into the
late 1980's. Since 1990-1991 a decrease in tiger numbers has been
the result of a decreasing prey base and wide-spread poaching.
Thanks to the efforts of scientists, international and Russian
organizations, and a decrease in the demand for tiger products,
poaching pressure has decreased, providing a basis for cautious
optimism. nonetheless, it is impossible to give a completely
positive prognosis for the future. An imbalanced ratio between
the tiger and key prey species is presently strongly pronounced
in many regions' and conditions continue to worsen. Considering
the present difficult economic situation, we can not count on
quick, positive changes in hunting management, or the eradication
of poaching. The strategy for tiger conservation must remain one
of complete protection of the species. The results of this census
lay the foundation for delineating an extensive set of
recommendations for tiger conservation. With the completion of
the census, we now have a good estimate of the number of tigers
in the Russian Far East, and where they are distributed. This
information provides a basis for estimating the minimum viable
population of tigers, and for delineating a conservation plan to
insure the long-term survival of the Amur tiger.
LITERATURE CITED
Abramov, K. G. 1965. Amur tiger and relic fauna of the Far East.
Notes of the Primorski Branch of the Geographical Society, USSR.
K24).
Anonymous. 1994. Amur Tiger Program: action plan for conservation
of Panthera tigris altaica. International group for the
conservation of the Amur tiger.
Faust, T., and R. Tilson, 1994. Estimating how many tigers are in
Sumatr: a beginning. pp. 11-38 in: Sumatran tiger population and
habitat viability analysis report. Padang, West Sumatra.
Kaplanov, L. G. 1948. The tiger in Sikhote-Aim. pp. 18-49 in
"Tiger, elk, moose". MOEP, Moscow.
Karanth, K. U. 1987. Tigers in India: a critical review of field
censuses. pp. 118-132 in Tigers of the world: the biology,
biopolitics, management and conservation of an endangered
species. Noyes Publications. Park Ridge, N. J.
Karanth, K. U. 1993. Relevance of big cat numbers to their
conservation. Cat News 19:11-12.
Kazarinov, A. P. 1972. Status, distribution, and numbers of
tigers in the Far East. pp. 401- 402 in: Zoological
problems in Siberia. Siberian Branch of the Institute of Biology,
USSR Academy of Sciences. Nauka, Moscow.
Kudzin, K. F. 1966. Tigers of Primorye. pp. 8-53 in Agricultural
production sssss in Siberia and the Far East. MSK USSR
Matyushkin, E. N. 1977. Choice of routes and establishment of
territories of the Amur tiger. pp. 146-178 in Behavior of
Mammals. Nauka Press, Moscow.
Matyushkin, E. N., and A. G. Yudakov. 1974. Tracks of the Amur
tiger. Hunting and Hunting Economy 5: 12-17.
Mescheryakov, V. S., and S. P. Kucherenko. 1990. Number of tigers
and ungulates in Primorsky Krai; recommendations for protection
and rational use. Final report. All Soviet Scientific Research
Institute of Hunting Management, Far East Division of Primorye
Commercial Hunting, and Primorsky Cooperative for Commercial
Hunting. Nikolaev, 1. G., and V. G. Yudin. 1993. Tiger and man in
conflict situations. Bull. MOEP Dept. Biology 98(3):23-36.
Pikunov, D. G. 1990. Number of tigers in the Far East USSR. 5th
Meeting of the All-Soviet Theological Society.
Pikunov, D. G., B. 1. Bazilnikov, B. N. Ribachook. 1983. pp.
130-131 in: Present area, numbers, and structure of the
distribution of tigers in Primorsky Krai. Rare Species of mammals
in the USSR and their protection. Nauka, Moscow.
Pikunov, D. G., and A. P. Bragul. 1987. Organization and census
methods for the Amur tiger. Organization and methods of surveying
commercial and rare species of mammals and birds in the Far East.
DVNT AN USSR, Vladivostok.
Sankhala, K. 1979. Tigers in the wild - their distribution and
habitat preference. pp. 43-59 in: "1st International Tiger
Symposium". Zool. Garten Leipzig.
Widodo, R., and C. Santiapl Uai. Conservation of Sumatran tigers
in Indonesia. pp. 85-92 in: Sumatran tiger population and habitat
viability analysis report. Padang, West Sumatra.
Yudakov, A. G., and I. G. Nikolaev. 1973. Status of the Amur
tiger (Panthera tigris altaica) in Primorsky Krai. Zool. J.
52(6):909-919.