Seasonal and sexual variation
in diel activity rhythms of pine marten Martes martes
in the Bia³owie¿a National Park (Poland)
Zalewski A. 2001. Seasonal and sexual variation in diel activity rhythms of pine marten
Martes martes in the Bia³owie¿a National Park (Poland). Acta Theriologica 46: 295–304.
From 1991–1996, the activity rhythms of 14 radio-collared pine martens Martes
martes (Linnaeus, 1758) (6 males and 8 females) were studied in the pristine deciduous
and mixed forests of the Bia³owie¿a National Park. Tracking data (5823 h) indicated
that the activity rhythms of pine martens varied between sexes and seasons. In spring,
male activity peaked at 20.00–00.00 h, whereas in summer and autumn–winter, activity
was bimodal, peaking at 18.00–22.00 h and 02.00–04.00 h. Female activity in spring was
more evenly distributed than that of males, but in summer their activity peaked at
20.00–00.00 h, while in autumn–winter females had a bimodal rhythm with peaks at
18.00–20.00 h and 02.00–06.00 h. In breeding females, activity rhythms changed in the
course of pregnancy and nursing. On average, martens started their activity 73±209
(SD) min before sunset and finished 87 ± 245 min after sunrise. Females became active
earlier than males but both sexes terminated activity at the same time. For both males
and females the daily activity rhythm was not related to the diurnal course of
Mammal Research Institute, Polish Academy of Sciences, 17-230 Bia³owie¿a, Poland,
Key words:Martes martes, activity rhythms, thermal stress, Bia³owie¿a National Park
Animals adapt their circadian activity to diurnal variation in their environment,
food availability, predation risk, and reproduction constraints (Aschoff 1964, Daan
and Aschoff 1982). Each of these factors plays a different role relative to season but
two factors have often been used as an explanation of predator’s activity rhythms:
predator-prey synchronisation and predation risk. It is assumed that increased
predator-prey synchronisation of activity leads to increased predator hunting
success. Many studies focus on this factor as an explanation of predators activity
rhythms (Ables 1969, Gerell 1969, Schuh et al. 1971, Curio 1976, Koop and
Velimirov 1982, Zielinski et al. 1983, Ferguson et al. 1988, Lodé 1995, Lariviere and
Messier 1997). The pine marten Martes martes (Linnaeus, 1758) prey mainly on
small rodents but the composition of their diet changes between seasons (Grakov
1981, Jêdrzejewski et al. 1993). In Bia³owie¿a National Park, bank voles Clethrio-
Acta Theriologica 46 (3): 295–304, 2001.
PL ISSN 0001–7051
nomys glareolus are the preferred prey species throughout the year and constitute,
on average, 32% of the biomass consumed by martens (Jêdrzejewski et al. 1993).
Avoidance of predation by small and medium-sized predators themselves has also
been suggested as the only adequate explanation of patterns of activity (Geffen and
Macdonald 1993, Drew and Bissonette 1997). The pine marten is a medium-sized
mustelid and could be killed by many predators and raptors (Korpimäki and
Norrdahl 1989, Lindström et al. 1995, Okarma et al. 1997).
Seasonal variation of activity patterns, however, was strongly affected by
variation of weather and reproduction constrains. Since the pine marten has a thin,
elongated body conductive to rapid heat loss (Iversen 1972), its activity rhythm
may be influenced by variation in diel temperature. At low temperature martens
curtailed their activity, however, they were mostly active at night (Zalewski 2000).
In winter, the American marten Martes americana was active during daylight
hours when temperature was higher than during the night (Thompson and Colgan
1991). Male pine martens are 33% larger than females. As a consequence females
need to reduce their activity during periods of cooler temperature much more than
males. In winter, the smaller females need to be active more often due to higher
possibility of starvation but they are active for a shorter duration (Zalewski 2000).
It could be expected that females would be active more evenly in the day.
The different investment in parental care by males and females can also affect
activity, and sexual differences in activity pattern are likely to occur, especially in
spring and summer. At this time females invest their energy in parental care in
order to maximise breeding success. In spring, females leave their cubs for short
periods, but duration of activity did not differ from that in males (Zalewski 2000).
Thus female activity is more evenly distributed during the day, which make them
more active in daylight hours. This could result in females running a higher
predation risk by raptors.
In this paper, I examine circadian rhythms of pine marten activity over a five-
-year period in the last remnant of pristine deciduous and mixed forests in the
European lowlands, where the pine martens exist amongst very rich communities
of prey and other predators (Jêdrzejewska and Jêdrzejewski 1998). The area has
not been exploited for timber and the level of human penetration is very low.
Therefore, human impact on marten behaviour is negligible. In this paper, I
analysed: (1) seasonal variation in activity rhythms of pine marten; (2) differences
in the daily activity rhythms between male and female; (3) variation of females
activity rhythms in pregnancy and nursing.
The study was conducted in an area of north-east Poland (52°43’N, 23°54’E) within the strict
reserve of Bia³owie¿a National Park (47.5 km2– BNP). The Park is part of a large primeval woodland
covering over 1250 km2, in which old-growth forest areas are dominated by oak-lime-hornbeam stands
(44.4% of area) comprising hornbeam Carpinus betulus, oak Quercus robur and lime Tilia cordata,as
well as scattered spruce Picea abies. Two other main forest types are mixed coniferous (dominated by
296 A. Zalewski
spruce and pine Pinus silvestris) and ash-alder (dominated by black alder Alnus glutinosa and ash
Fraxinus excelsior). More detailed information on the vegetation of BNP is given by Faliñski (1986).
Old-growth forests of BNP are characterised by various age of trees (mean age of tree stands is 130
years), the presence of snags and downed logs of large diameter, and small gaps in the canopy. Human
penetration (mainly pedestrian tourists) of the National Park is very low and only occurs in the
south-western part of the study area.
The climate is transitional between continental and Atlantic types but continental features prevail
(Olszewski 1986). During the study (1991–1996), January or February were the coldest months, with
average monthly temperature reaching as low as –8.5°C, and a maximum snow cover of 63 cm. The
warmest month was July, with average monthly temperature reaching a high of 22.5°C. More detailed
information about the area as well as maps of the terrain are given by Jêdrzejewska and Jêdrzejewski
Material and methods
From 1991 to 1996, 6 male and 8 female pine martens were captured in box traps and equipped
with radio-collars (AVM or Lotek; 12–25 g). Martens were located at least once daily and on some days
they were monitored continuously for a time span of 4–24 h. During such continuous radiotracking,
locations were taken at 15-min intervals. Marten behaviour was categorised as active (frequently
switching pulse amplitude) or inactive (pulse amplitude unchanging). Since slight movements of the
animal in a resting site could have been confused with true locomotor activity, the activity was
recorded as occurring in the resting site if the marten’s spatial position did not change despite a slight
variation in the signal. In total, 23 294 activity fixes (5823 h) were recorded (15203 for males and 8091
for females). For analysis of the diel activity rhythms in each season, the total number of fixes during
2-hour periods were taken as 100 so active fixes were thus calculated as percentages. Pooled data from
three seasons: spring (16 March – 15 June), summer (16 June – 15 October) and autumn–winter (16
October – 15 March) were analysed. The first date upon which natal dens were located was accepted as
parturition date, although such estimates may be 2–4 days after the actual birth.
Circadian rhythms of marten activity were also correlated with diel course of ambient temperature
measured in 1960, in oak-lime hornbeam forest of BNP at 0.2 m above ground (Olszewski 1986). In
1960, average temperature in January (–4.5°C) was within the range of mean January temperatures in
my study period (–0.9 to –8.5°C). The mean daily snow cover in 1960 was 6.2 cm, again within the
range recorded in 1991–1996 (1.7 to 20.7 cm).
Diel distribution of martens activity was not homogenous. Generally, activity
levels were higher between 18.00–06.00 h followed by a decline during daylight
hours (Fig. 1). In both sexes activity varied significantly between seasons (G-test
for homogeneity of percentages: males – Gfrom 25.5 to 38.0, p< 0.01, df = 11;
females – Gfrom 49.3 to 69.5, p< 0.001, df = 11). In spring, male activity peaked at
20.00–00.00 h (91 and 87% of active fixes) and was at its lowest at 08.00–14.00 h
(9–10%, Fig. 1). In summer, males displayed a bimodal activity rhythm with peaks
at 18.00–22.00 h (75 and 77% of active fixes) and 02.00–04.00 h (79% of active fixes;
Fig. 1). Daylight activity (minimum 10% between 12.00–14.00 h) was noticeably
higher in summer than during any other season. In autumn–winter, male martens
also displayed a bimodal rhythm of activity with a maximum of 50–60% of active
Activity rhythms of pine marten 297
298 A. Zalewski
Fig. 1. Circadian activity rhythms of male (n= 6) and female (n= 8) pine martens Martes martes
during spring (15 March–15 June), summer (16 June–15 October) and autumn–winter (16 October–15
March) in the Bia³owie¿a National Park (Poland) in 1991–1996. For each 2-hour period fixes when
martens were found active were calculated as percentage of all fixes taken at 15-min intervals. Total n
fixes in 2-h periods varied from 83 to 1741. Dark horizontal bars indicate the shortest and the longest
time from sunset to sunrise in each season.
Active out of a resting site (moving) Sunset to sunrise tim
Active in a resting site
12 16 20 004 08 12
12 16 20 00408 12
12 16 20 004 08 12 12 16 20 004 08 12
12 16 20 004 08 12
12 16 20 00408 12
Autumn - winter
In spring, female activity rhythms were more evenly distributed than those of
males. Their level of activity shown for 2-hour periods varied from 29% to 63%,
except between 04.00–10.00 h, when it was lower (13–18%, Fig. 1). In summer,
female activity peaked between 20.00–00.00 h (89–91% of active fixes). In autumn–
–winter, females, like males, had a bimodal activity rhythm, exhibiting a bigeminus
pattern (Aschoff 1966) with the first peak markedly higher than the second.
These data show different rhythms of activity in males and females, especially in
spring (spring: G= 62.4, p< 0.001; summer: G= 22.3, p< 0.05; autumn–winter:
G= 42.4, p< 0.05, df = 11 in each case). In spring, females were more active than
males between 10.00–16.00 h (Gfrom 4.5 to 17.9, p< 0.05, df = 1) but males were
significantly more active between 20.00–00.00 h (G= 8.2 and 12.5, p< 0.01,
df = 1; Fig 1). In summer, the activity rhythms of the sexes were closer than at any
other season but there were still significant differences between 22.00–00.00 h
(G= 6.9, p< 0.01, df = 1) and 02.00–04.00 h (G= 4.0, p< 0.05, df = 1). During
autumn– –winter, females decreased their activity to a much greater extent than
males between 20.00–00.00 h (G= 6.6 and 18.6, p< 0.05, df = 1) and 02.00–04.00 h
(G= 6.3, p< 0.05, df = 1) but were more active between 10.00–14.00 (G= 6.3 and
5.2, p< 0.05, df = 1; Fig. 1). Marten activity at resting sites was always of short
duration (on average 0.3–1.1% of all fixes in 2-h periods, ie 5–24 min/day) with the
exception of females in spring (on average 3.6% of fixes, ie 51 min/day; Fig. 1).
In all seasons daily ambient temperatures are lowest between 03.00–06.00 h.
The daily activity pattern of both males and females was not positively related to
the diurnal course of temperature (Kendall’s coefficient of rank correlation: for
males tfrom –0.27 to –0.30; for females tfrom 0.09 to 0.24; p> 0.05). However,
between 04.00 and 08.00 h, when ambient temperature was at its lowest, martens
often decreased their activity (especially females in spring).
For breeding females activity rhythms changed during the course of pregnancy
and nursing. Indeed, in the last month of her pregnancy, female 6 was even active
between 14.00–06.00 h (Fig. 2). During the first month of the cubs’ life, activity
rhythms of all lactating females showed two peaks and similarly all females
decreased their activity between 02.00 to 10.00 h. In the same period, however,
females were generally more active at their resting sites, especially between
06.00–22.00 h. Periods of activity at the resting site decreased during the second
month of the cub’s life and two females were again active outside the resting site
between 14.00–02.00 h (Fig. 2).
On average, martens started their activity 73 min (SD ± 209) before sunset and
terminated it 87 ± 245 min after sunrise. However, the onset and cessation of
activity was highly variable according to both sex and season (Table 1). Overall
females started their activity earlier than males (two-way Kruskal-Wallis ANOVA:
H= 6.4 , p< 0.01) and both sexes started activity earlier in summer and later in
winter (H= 45.9, p< 0.001). Males and females both terminated activity at the
same time (H= 0.05, ns) with termination time later in summer than in winter
(H= 40.1, p< 0.001; Table 1).
Activity rhythms of pine marten 299
300 A. Zalewski
10 14 18 22 02 06 10
10 14 18 22 02 06 10 10 14 18 22 02 06 10
10 14 18 22 02 0610 10 14 18 22 02 0 610
10 14 18 22 02 06 10
10 14 18 22 02 06 10
6(15 Mar - 16 Apr 1993)
6(17 Apr - 18 May 1993)
(16 May - 17 Jun 1992)
(4 Apr - 5 May 1992)
(6 May - 7 Jun 1992)
(7 May - 8 Jun 1992)
(19 May - 20 Jun 1993)
Active out of den
Active in den
First month after parturition
Second month after parturition
Percentage of fixes
Fig. 2. Circadian activity rhythms of female pine martens during their pregnancy, the first and the
second month after parturition in the Bia³owie¿a National Park. Total nfixes in 4-h periods varied
from 40 to 150.
The results show that the activity rhythms of pine martens varied significantly
between sexes and seasons. The differences between sexes could be due to
differences in the reproduction investment of both sexes and this was most evident
during spring. In this season, females care for their cubs (Grakov 1981). They leave
the cubs for short bouts because unattended cubs may be susceptible to thermal
stress (Frost and Krohn 1997). In spring, the activity of females was more evenly
distributed throughout the day than that of males. Similar behaviour has been
observed in females of other predator species (Paragi et al. 1994, Lariviere and
Messier 1997). The even distribution of female activity during this season was
apparently related to their care for young, thus producing more frequent activity
bouts in a day, although each bout was of shorter duration than those of males
(Zalewski 2000). However, both sexes were active for a similar duration (Zalewski
2000). Therefore, female activity started earlier in the day compared to males
because they often had breaks in their activity to care for their cubs. In spring,
females decreased their activity during the coldest part of the day (04.00–08.00 h)
returning to their den at that time. This was particularly marked during the first
month of a cub’s life. In spring, females were also active longer in dens than at any
other season, especially during the first month of cub’s life. Females choose
breeding sites in high cavities of trees (Zalewski 1997), where the risk of predation
is low. These sites are accessible only to other martens. It is possible that reversal of
activity between males and females is affected by male predation on cubs. However,
there is no evidence of intraspecific predation. In America, male martens were
Activity rhythms of pine marten 301
Table 1. Daily onset and cessation of activity period in relation to sunset and sunrise for pine martens
Martes martes in the Bia³owie¿a National Park, 1991–1996. Positive and negative values indicate time
(min) following and preceding sunset or sunrise, respectively. n– number of observation.
Onset of activity in relation to sunset
Cessation of activity in relation to sunrise
martens nAverage (SD) nAverage (SD)
Males 17 +90 (178) 17 +113 (185)
Females 21 +210 (151) 16 +113 (275)
Males 27 +125 (137) 23 +224 (143)
Females 7 +250 (166) 14 +254 (170)
Males 16 –190 (208) 19 –76 (128)
Females 12 –55 (94) 11 –209 (292)
observed in breeding dens, scent marking or robbing the female of her prey, but not
killing cubs (Jones et al. 1997). In summer, both males and females synchronized
their activity pattern due to mating season.
In the Bia³owie¿a National Park, the daily activity pattern of both males and
females were not related to the diurnal course of temperature during any season. In
Ontario, American martens experiencing severe weather conditions remained in
their resting sites all night and confined much of their activity to daylight hours
when temperature were highest (Thompson and Colgan 1991). In California, the
winter activity of martens was distributed more homogeneously throughout 24 h
cycles (Zielinski et al. 1983, Martin 1987). In BNP, pine martens were only active
during the night in the winter, despite the fact that temperatures were lowest then.
In winter, however, females decreased their activity in colder periods of the night.
Other studies have recorded only nocturnal activity amongst pine marten popu-
lations (Marchesi 1989). Drew and Bissonette (1997) suggest that the avoidance of
daylight by American martens was due to higher predation risk. This explanation
cannot be applied to pine martens in BNP. European pine martens are killed by the
lynx Lynx lynx, red fox Vulpes vulpes or large raptors (Nyholm 1970, Korpimäki
and Norrdahl 1989, Pulliainen 1981, Lindström et al. 1995, Okarma et al. 1997). In
BNP, most of raptors are absent in winter (Pugacewicz 1996), while lynx and red
fox are mainly nocturnal (Schmidt 1999, R. Kowalczyk, pers. comm). In winter,
therefore, predation risks for martens seems to be even higher at night.
It is often assumed that predators synchronise their activity rhythms with that
of their main prey (Ables 1969, Mikkola 1970, Curio 1976, Zielinski et al. 1983,
Weber et al. 1994, Lodé 1995). Yellow-necked mice Apodemus flavicollis were active
at night (Buchalczyk 1964, Wójcik and Wo³k 1985) and the activity pattern of pine
martens correlated with that of this species. However, martens consistently preyed
on mice less than could have been expected from the proportion of mice in the total
biomass of forest rodents determined by trapping (Jêdrzejewski et al. 1993). This
suggests that the activity rhythms of both predator and prey are not related but
depend on other factors and synchronisation of predator-prey patterns of activities
do not implicate predator specialisation in this prey. Bank vole are the preferred
prey species by pine marten (Jêdrzejewski et al. 1993). In spring and summer, bank
voles showed activity patterns with several peaks throughout the day and night
(Buchalczyk 1964, Wójcik and Wo³k 1985). During these two seasons, the activity
patterns of both male and female pine martens did not synchronise with those of
bank voles. In autumn, however, bank voles’ activity displayed two peaks: at
18.00–20.00 h and 04.00–08.00 h (Buchalczyk 1964, Wójcik and Wo³k 1985). This
coincided with the circadian rhythm of pine marten activities (especially males) at
this time of year.
In conclusion, reproduction clearly affected the intersexual variation in the
circadian rhythm of marten activity. However, marten activity behaviour does not
clearly relate to the activity rhythms of its main prey nor to thermal stress. There is
no evidence either to suggest that martens are active at night to avoid predation.
302 A. Zalewski
Acknowledgements: I wish to thank the technical staff of MRI (E. Bujko and K. Zub), students of
Farnborough College of Technology (England), Warsaw University, the Jagiellonian University in
Kraków, and Earthwatch Research Corps for their help in field work. Special thanks go to
Dr B. Jêdrzejewska for her help in the preparation of this manuscript. My thanks to Prof S. W.
Buskirk and Z. Pucek for their comments on an earlier draft. The study was supported partly by the
Mammal Research Institute PAS budget and partly by a KBN 6 P205 080 06 grant.
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Received 1 June 2001, accepted 22 June 2001.
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