Chapter 8:
Daily Travel Distance and 24-Hour Activity Rhythm
Until quite recently, it was generally accepted as fact that the Amur
tiger regularly completes extremely long journeys.š The source of this idea
was, apparently, statements by N. A. Baikov (1925) that tigers can cover
a distance of 80 or even 100 km over the course of 24 hours during their
search for prey.š An estimate of the distance traveled per day by these animals
that was based on information from winter tracking was first given by L.
G. Kaplanov (1948) as being 20-50 km.š However, the data of L. G. Kaplanov
pertain to a period when the population was at an extremely low density.š
Since that time, the situation has changed greatly: in many regions, including
our long-term study site, the population density of tigers has now approximated
the natural density that is a response to the ecological capacity of the
land.
Although in recent years new information on the ecology of the Amur tiger
has accumulated rather rapidly, a clear lack of adequate data allowing us
to approach a determination of the daily travel distance of the animals
on a methodologically rigorous basis has been felt up until the present
time.š The index characterizing the movements of the animals over the course
of a 24-hr period is of interest from various perspectives.š Without this
index, it is impossible to analyze the daily activity rhythm of tigers.š
At the same time, the daily travel distance allows us to form judgments about
the characteristics of territory use by tigers and about the animals' energetic
expenditures during the search for and the capture of prey.š Finally, knowledge
of the daily travel distance plays an essential role during a census of tigers.
Determining a tiger's daily travel distance over a 24-hr period by means
of tracking is not a simple task.š If we were to equate daily travel distance
to the distance between two long-term lairs, it would be possible to allow
considerable errors to enter into our estimate.š An interchange of activity
phases over the course of 24 hours occurs frequently in tigers.š In addition,
this rhythm cannot be fitted into any sort of simple, unchangeably repeating
pattern.š In order to maintain the maximum degree of objectivity in the
estimation of daily travel distance, we regarded it as necessary to proceed
on the basis of precisely recorded distances that had been walked by the
animals during a definite time period (Yudakov & Nikolaev 1979).š Such
precisely determined data points are relatively few in the total aggregate
of the data collected.š They are based on direct encounters with animals,
on the appearance of their footprints somewhere at a reliably determined
time, on the "referencing" of observations to the beginning and end of snowfalls
or to times of formation of a snow crust or to thawing periods.š Data from
a long period of tracking, in which the "daily (or 24-hour)" sections of
the path are separated out with a greater or lesser degree of probability,
are included only as a supplement to these data. š
š
Male Tigers:
1. On January 17, 1971, a fresh track was discovered on a road running
along the valley of Petrov Stream.š The track was "cut off" (i.e.,
enclosed within a circle of paths made by an observer) at 11:00 hrs.š Later
on during tracking, we succeeded in establishing the fact that the animal
had stayed at this time on a mountain spur between two small narrow side
valleys.š The tiger was separated from the advancing human by a distance
of several hundred meters.š Then the tiger traveled to the mouth of Tigrovyi
Stream, where he appeared not earlier than 17:00 hrs, since his tracks crossed
over the tracks left by a person at that time.š The tiger completed a path
that was 6 km in length (with 2 km of this distance being along a road) in
not less than 6 hours.š On this section of the tiger's path, we noted one
unsuccessful hunt and three laying places that were used for short periods.
2. The footprints of an animal that had gone towards a human observer
and had then retreated upon the person's approach were encountered at 19:00
hrs on a road in the valley of Bogdanov Stream on January 31, 1972.š From
here, the tiger moved to the slopes of the right bank of Bol'shoi Stream,
where we found his long-term lair in a wild boar den.š A snowstorm began in
the middle of the night of February 1-2 that continued until noon on February
2.š The tiger spent all this time in his lair, since his footprints upon emerging
from this place, which were tracked later, were not even lightly covered
with snow.š The tiger had covered a distance of 17 km from the site of his
encounter with the human up to his lair. The tiger spent almost two days
(minus 5-7 hours) on this journey (together with the subsequent long rest
period).š In addition to the lair mentioned above, two more long-term lairs
were found along the path of this tiger, one of which clearly pertained to
the dark portion of the 24-hr period.š Also, we discovered 24 laying sites
that had been used for short periods.š The tiger twice hunted for Manchurian
deer and once for wild boar; all hunts were unsuccessful.
3. Clear weather and the thaws that had been observed during the time of
the male tiger's movements on March 7, 8, and 9th, 1972, allowed us to record
two of his daily travels with precision.š Having arisen from his laying site
after noon on March 7, the tiger walked 6 km on wet snow (Fig. 10), i.e., up until the end of the daytime
thaw.š After going 3 km farther, he once again laid down for a long time.š
We discovered the next day's lair, where the animal stayed on March 8, at
a distance of 8 km from his last lair.š The animal also got up from this lair
after noon. The path that he had walked over the course of 24 hours equaled
17 km.š Twenty-five laying places that were used for short periods (in addition
to the long-term lairs) were noted over this distance.
The tiger's path for the following 24-hour period--up to the day lair
of March 9--was determined by using the very same signs and added up to 18
km (13 km of which were walked along a road).š The tiger killed a Manchurian
deer near the road along this path.š There was a long night lair near the
prey (i.e., at the kill site).š However, the corpse of the Manchurian
deer remained almost untouched.š There were 19 laying places that the tiger
used for brief periods on this section of his path.
4.š We tracked a path of total length 144 km (17 km of this along a road)
for the same male tiger (i.e., the one mentioned in note # 3).š This
distance, including two paths, each walked over 24 hours (and which have been
described above), was walked over the course of 19 days.š The beginning of
this segment was determined with a precision of + 24 hours.š The male
tiger crossed the valley of Bol'shoi Stream somewhat earlier than did a tigress
that had walked at this place on the morning of February 29.š After more
than half a month had passed (after noon on March 18), he was frightened away
by observers, who had continuously followed his tracks.š Along this 144 km-long
path, the tiger had killed a young wild boar (which had been eaten in its
entirety) and two Manchurian deer (about 3/4 of one of them was eaten, the
second was scarcely touched).š Furthermore, together with the tigress, the
male ate a wild boar that she had killed; he also fed on the remains of his
old prey (the Manchurian deer), which he had killed a month earlier.š We
found 20 long-term lairs and 224 laying places that had been used for brief
periods.š Of seven long-term resting sites, where the time the tiger spent
at them has been established precisely, six were diurnal sites (three near
prey) and one, also at a kill site, was a nocturnal resting site.
5.š On November 24, 1972, the tiger, having arisen from the diurnal lair
on which he had stayed during a snowstorm, walked 4 km along a logging road
and came upon the tracks of a person who had passed here at 18:00 hrs on
that same day.š The site where he came upon the human's tracks was also taken
as the beginning of the precisely recorded segment of his path.š The tiger
appeared on the road soon after the human, since by around 23:00 hrs (when
the snowstorm ended), he had already walked 6 km along the road (having left
behind him seven laying sites that he had used for brief periods).š Following
along that same road, the tiger, after covering a distance of 10 km (as measured
from the beginning of the segment) laid down for a long time to one side
of the roadbed.š Not far from here (6 km), there was a cabin past which the
animal walked at 6:00-8:00 hrs on the morning of November 25.š At this time,
the observers were located in the cabin.š At a distance of 700 m from our
wintering quarters (i.e., the cabin), the tiger left the road and
went toward the river, where his long-term lair was later found (the animal
tried to steal a Manchurian deer, but he was unsuccessful in this).š The
tiger walked another 1.5 km farther and then turned from the road onto a
slope.
Figure 10.š The tracks of the "Emperor" tiger on wet snow.
At 18:30 hours on November 25, the tiger, which was already following the road in the reverse direction, abandoned the road, having been alarmed by an automobile that was driving up to the cabin.š Soon he once again emerged onto the road and moved farther along it.š The maneuvers of the tiger were discovered when the automobile drove away from the wintering cabin and caught up with the tiger; we saw the animal from the road as it passed swiftly by us.š The daily travel distance of the tiger, from 18:00 hrs on November 24 until 18:45 hrs on November 25, equaled 23.7 km (of which 21.3 km were walked along a road).š This path was split up into several segments.š The tiger walked 16 km along the road from November 24 (after 18:00 hrs) until 6:00-8:00 hrs on November 25 (i.e., during the night).š Here he had two laying places that he used for extended periods (one of them used during a hunt that took place near morning) and 13 short-term resting places; here he had also made two unsuccessful hunting attempts on Manchurian deer.š From 6:00-8:00 hrs on November 25 up until 18:45 hrs on that same day, the tiger walked 7.7 km, of which 5.3 km constituted his path along the road during the dark part of the 24-hr period.š The tiger walked the remaining 2.4 km during the day.š We noted 3 long-term lairs and 17 laying places used for short periods over the distance that made up the tiger's daily journey.
6. The next daily path of the male tiger was followed beginning from
the end of the segment of his route that we have just described.š This journey
concluded with an encounter between the tiger and an observer on a road at
19:30 hrs on December 26.š At the beginning of the segment in question, the
tiger, which had been disturbed by a moving automobile, laid down for a long
time, having moved away from the road for a distance of 70 m; then he returned
to the road.š Walking 8 km farther, he left the road and proceeded for 6
km along a slope and a river valley.š Then, he again appeared on a road,
and walked along it for a distance of 11 km.š After this, the tiger turned
into the forest and, after going a distance of 13 km, crossed in daytime
over a mountain spur, which divided the valley of the main river from its
tributary.š In this way, he emerged onto another road, one running along
the valley of the tributary.š Here, after going 3 km on his route, the tiger
encountered a human at 19:30 hrs.š In this case, it was precisely established
that the animal emerged onto the road during the dark part of the 24-hr period.š
This time the tiger covered a distance of 41 km over the course of 24 hours.š
This was the maximum distance calculated from all our data.š At night, the
tiger walked 22 km on a road and 6 km off the road.š On this path, we noted
29 laying places used for brief periods and one long-term lair.š The diurnal
journey equaled 13 km; here we found 31 laying places used for brief stops
and 3 long-term lairs.š We noted one unsuccessful hunt on a Manchurian deer,
which the tiger pursued for a distance of approximately 2 km.
7. On December 15, 1972, a fresh track of a tiger was discovered on
a road along a valley of a stream.š Having turned off the road, the animal
soon killed and almost completely ate a yearling wild boar.š The tiger, having
returned to the road, walked along it for 7 km.š Then he crossed over a mountain
spur, which resembled a promontory, into a valley of the river and headed
upward along the valley.š A diurnal lair was found at the foothills of the
slope.š Moving farther along the valley, the tiger ran across the footprints
of a human, who had passed along the shore of the river.š The time of the
tiger's appearance at the person's tracks can be established with a precision
of several hours.š It was clear that the animal had already walked here by
December 16.š In this manner, the journey of the tiger over the course of
24 hours comprised 17 km (3 km of which was walked along a road).š In addition
to the diurnal lair, two more long-term lairs, one of them with prey, were
observed on this segment of his route.š The number of short-term laying places
was 38.
8.š The section of the route that has just been described can be taken
as the beginning of a long journey, which took the tiger approximately 13
days.š The end of this segment is located at a lair that dated to December
28 on a mountain spur that the tiger used for a long time.š In total, the
tiger walked 115 km (40 km along a road) over the course of 13 days.š Prey
(yearling wild boar) was found four times over this distance.š All the piglets
that the tiger caught were completely eaten.š Three unsuccessful hunts on
Manchurian deer and one unsuccessful hunt on a wild boar were noted.š Long-term
lairs numbered 18, of which 4 were associated with prey.š All (five) long-term
lairs that we succeeded in linking to a definite part of the 24-hr period
were used during the daytime.š We found 285 laying places that were used
for brief periods.
Tigresses:
9.š During a snowstorm on the night of March 9-10, 1971, the tigress left
the road, which had been laid down alongside the valley of a stream, and
killed a dog after walking 1.8 km along her path.š The clear weather, which
arrived on March 11 after the snowstorm, allowed us to establish that the
animal remained with the prey (at the kill site) on this day.š Early on the
morning of March 12, the tracks of the tigress were once again observed along
a road; these footprints were not there on March 11.š Thus, the tigress spent
not less than 1.5 days (i.e., not less than 36 hours) with the prey;
the dog was completely eaten.š Before once again going out onto the road,
the animal walked in closed, loop-like path near the prey. Apparently, this
was on the evening of March 11.š The length of this looped path was approximately
4 km.š In total, from the time of leaving the road (before the attack on
the dog), and up until her return to the road, the tigress had walked a distance
of 7.5 km.š This journey involves a time interval of not less than 1.5 days
and not more than 2 days.š In addition to a long-term lair near the dog that
she had killed, 16 laying places that the tigress had used for brief periods
were noted along the her path.
10. On January 22, 1972, in the valley of Bol'shoi Stream, a fresh track
of a tigress, which had traveled along the right bank of the stream, was
discovered.š At 14:00 hrs a human passed by this site, but no tiger tracks
were present at that time.š The tiger tracks had already appeared by 16:00
hrs on that same day.š Thus, the tigress crossed over this area between 14:00
hrs and 16:00 hrs.
On the morning of January 26 (the tracks were not present on the eve of this
day), the tigress passed by here going in the opposite direction not far
from the location of her footprints that we had noted earlier.š Over the
course of 3.5 days, the tigress walked about 29 km.š Within the limits of
this segment of her path were found the remains of a yearling wild boar that
the tigress had killed; the tigress ate approximately 25% of the prey.š In
addition to the long-term lair near the prey, we found yet another long-term
lair and 41 laying places that the tigress had used for brief periods (and
which had melted away to varying degrees).
11. On February 29, 1972, the tigress crossed a road in the valley of
Bol'shoi Stream.š She had walked here during the early morning; her footprints
were not present during the evening of the previous day.š Over the course
of the following 6.5 days, the animal traveled 56 km, having left behind
her over this distance 5 long-term lairs (2 of them with prey) and 45 laying
places used for brief periods. Three of these long-term lairs (including
those near prey) were clearly diurnal lairs.š The tigress killed a wild boar,
which she ate jointly with the male tiger, and a yearling Manchurian deer.š
The Manchurian deer was almost completely consumed by her.š
12. This segment of our tracking is a direct continuation of the previous
one.š On the evening of March 6, the tigress emerged onto a road that had
been laid down along the valley of a river.š The fact that she had been walking
during the daytime prior to this can be judged from the nature of the footprints,
which are clearly imprinted on wet snow.š The thaw took place during the
daylight hours; during the night, the temperature dropped to freezing, and
the snow became covered with an ice rind.š This time, we followed the animal
itself, only remaining a short distance behind her.š The tigress walked along
the road for 8 km, she also completed this journey despite the encroaching
darkness.š Such a conclusion is supported, in particular, by the absence
of characteristic departures from the road, such departures reflecting the
reaction of tigers to approaching vehicles.š At night, the movement of logging
trucks is a very rare event at this site.š The tigress turned from the road
onto a slope where her nocturnal lair was found.š The tigress arose from
her lair early on the morning of March 7. Her exit from the lair in the early
morning hours is supported by the fact that her subsequent journey over a
distance of 6 km right up to the site of her daytime lair ran over a snow
crust.
She abandoned her daytime lair in the middle of the day.š After going a distance
of 300 m, she laid down right in the sun, and rolled in the snow.š From this
site, the animal continued her path while the daytime thaw was still in progress.š
After going 6 km across wet snow, the tigress killed a roe deer.š The prey
was quickly and almost completely eaten.š The animal rested in the full sun
near the prey.š In the evening, the tigress moved farther on.š After going
a distance of 1.5 km on her path from the site of the successful hunt, the
animal began to walk on a snow crust.š
In addition to the lairs that we have noted, we found six briefly used
laying places (two of which were used during hunts) along the path from the
daytime lair to the kill site.š After consumption of the prey, yet another
short-term laying place and an unsuccessful hunt on a wild boar were noted.š
In sum, the tigress walked 22 km over the course of 24 hours (10 km of this
was walked along a road) with three long-term lairs (one with the prey) and
eight laying places used for brief periods.š If the present segment of the
path is added to the previous segment, then the distance of the entire journey
constituted 78 km walked over the course of 7.5 days.
13.š During the night of January 11-12, 1973, a male tiger walked along a
road in the valley of a stream; a tigress appeared on his track on the morning
of January 12th.š Avoiding the track of the male, she headed upward along
the valley of the stream.š After following her path for a distance of 7 km,
we found a laying place.š After walking a further 6 km, the tigress surmounted
a divide, after which she hunted successfully, killing a yearling wild boar.š
Her daytime lair was found nearby.š Approximately 1/3 of the prey was eaten.š
At 17:00 hrs on January 13, the remains of the piglet had still not managed
to freeze solid.š The tigress departed not long before the appearance of
an observer.š The animal covered a path of length 13 km over a time period
of a little more than 24 hours.š Two unsuccessful attempts to prey upon a
wild boar and upon a Manchurian deer were noted on this section of her path.š
Only one briefly-used laying place was observed on this segment.
14.š During the night of February 24-25, the tigress walked along a road
that ran along a river valley, then she crossed over to the opposite bank
of the river.š After almost 10 days, at 12:20 hours on March 6, the animal
was frightened away from its prey, an adult wild boar about half of which
had been eaten.š The tigress lived for a long time near the kill site of
the prey.š We found a track stretching from the remaining scraps left from
the tiger's kill to a den made by wild boar, where the tigress rested.š In
total, the tigress traveled for 39 km (only 1.5 km of which was walked along
a road) over the course of 9.5 days.š In addition to the adult wild boar,
she had killed and completely eaten a piglet during this time period.š There
were five unsuccessful hunts (one on a roe deer, and two each on wild boar
and Manchurian deer).š The tigress approached a yearling wild boar, which
had laid down in its den and which had died of starvation, in the valley
of a stream.š She dragged the boar to one side of the den, but she did not
begin to eat it.šš The long-term lairs along her path numbered five, two
of which were with prey (one was used at night while the other was used during
daylight).š We found 39 laying places that the tigress used for short periods
of time.
* * *
On the basis of the data that we have examined, the following mean indices
can be derived.š They are somewhat conditional, since the daily travel distance
of tigers is well known to be variable depending on whether the tiger is
traveling about his territory or is keeping to a particular section of his
territory, whether he hunts successfully or unsuccessfully, or whether he
is searching for prey or is eating prey that he has already killed.š Nevertheless,
the mean index reflects the degree of mobility of tigers, and characterizes
the temporal utilization of their territories by the animals.š The mean daily
travel distance of male tigers equals 9.6 km, while the maximum daily distance
is 41 km.š The latter value deviates quite sharply from the remaining values
and pertains to the travels of a male tiger (the "Lazy" tiger) that primarily
occurred along roads.š It is important to remember that the animal in question,
which did not possess his own permanent territory, led a nomadic way of life.š
It is difficult to determine the minimum daily travel distance of tigers,
since, while consuming prey and resting near the prey, this distance at times
does not exceed several hundred meters.
For tigresses, the mean value for travel over the course of 24 hours
is 7 km, while the maximum daily travel distance is 22 km.š These figures
pertain, as has already been mentioned, to tigresses without offspring.š
We did not succeed in obtaining such precise data on the daily travels of
a family that includes cubs.š The very nature of the tracks of families with
offspring (the cubs' tracks, their movements, and also those of the tigress
on small sectors of land) prevents such reliable determinations.š On the
basis of particular observations, it is possible to assume that females with
small cubs travel less than tigresses without cubs.š The well-known observations
of L. G. Kaplanov (1948) can also serve as illustrations of this statement.
In sum, the results that we have produced force us to reconsider the traditional
idea of the Amur tiger as an animal that is characterized by relatively rapid
and extremely wide-ranging travels within the area it inhabits.š Sedentary
tigers, which are guaranteed prey, rarely carry out long travels (Yudakov
& Nikolaev 1979).š Basing his ideas on observations made in the Sikhote-Alin
Nature Reserve, E. N. Matyushkin (1977) arrived at similar conclusions: in
his opinion, "in the presence of favorable food conditions, the 24-hour travel
distance of tigers does not normally exceed 15-20 km" (p. 167).
The daily travel distance of the animals cannot be identified with the distance
between two long-term lairs.š According to our data, the maximum distance
between two such lairs for males is significantly less than the maximum daily
travel distance: 21 km vs. 41 km.š Such differences can also be seen in the
case of tigresses: 15 km vs. 22 km.š Although the mean number of long-term
lairs for one 24-hour period is close to 1, their number can reach 5 over
the course of 24 hours.š The number of short-term laying places bears evidence
concerning the frequency of alternation between periods of activity and rest.š
For males, the number is, on average, equal to 15 per 10 km of their route,
while in the case of females the average equals 9 per 10 km of their route.š
These laying places that are not used for extended periods of time can also
be melted away to a greater or lesser degree; the demarcation between them
and the long-term lairs is in many instances one based on convention.š
With the Amur tiger, long rest periods are not strictly confined to a definite
part of the 24-hr cycle, although in general the animal prefers to rest in
the daytime.š Of 55 long-term lairs, for which we succeeded in establishing
the time of day with sufficient precision, 42 (76%) were used the daytime.š
In this regard, the preferential siting of the tigers' long-term lairs on
south-facing slopes (i.e., on sites that are well heated by the sun)
is also significant.š Approximately one third of the lairs, both diurnal
and nocturnal, that the predators left behind them were located near the
kill sites of their prey.
Summarizing the information presented above, the Amur tiger can be characterized
as an animal for which frequent changes in their activity phase typically
occur over the course of a 24-hour period.š Here the daily activity rhythm
of the animals is very plastic: deviations from a pattern of "daytime rest-night
travel" are observed quite often.š If it is correct to state that the Amur
tiger can complete long journeys over a short time period, then it is just
as true to make the opposite claim: that, during settled life on a defined
territory, their travel distances over the course of a 24-hour period lie
within quite narrow limits.