Social structure and habitat preferences of moose population in Biebrza National Park Mammal Research Institute, Polish Academy of Sciences, Białowieża Project: Biodiversity protection of Red Bog (Czerwone Bagno) - relic of raised bogs in Central Europe Włodzimierz Jędrzejewski Bogumiła Jędrzejewska Tomasz Borowik Kris Hundertmark Marcin Górny
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Social structure and habitat preferences of moose population in Biebrza National Park
Social structure and habitat preferences of moose population in Biebrza National Park. Włodzimierz Jędrzejewski Bogumiła Jędrzejewska Tomasz Borowik Kris Hundertmark Marcin Górny. Mammal Research Institute, Polish Academy of Sciences, Białowieża - PowerPoint PPT Presentation
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Social structure and habitat preferences of moose population in Biebrza National Park
Mammal Research Institute, Polish Academy of Sciences, BiałowieżaProject: Biodiversity protection of Red Bog (Czerwone Bagno) - relic of raised bogs in Central Europe
• Observations by park personnel– group size and composition– location– date
• 1998-2010 (most from Sept. 2006-February 2010)• 1534 observations• 2770 total moose• Classified as adult male, adult female, juvenile, or calf• 2041 adults of known sex
Sexual segregation• Sexes use different areas/habitats outside of the mating season
• Common in ungulates with body-size dimorphism
– Larger difference in body size is associated with more extreme sexual segregation
• Some hypotheses (among others)
– Predator avoidance by females and calves
• Females choose less risky environments whereas males choose riskier environments to gain back
condition after breeding season
– Food selection
• Females (smaller body size) seek out high-quality forage
• Males (larger body size) seek out more abundant but more fibrous forage due to their gut
morphology
– Activity budget
• Larger-bodied males spend more time ruminating and less time feeding than
smaller-bodied females and therefore can’t synchronize movements
Moose group dynamics• Group size: mean = 1.6 (SD 1.3), range = 1—20 • Adult males: 1—11• Adult females: 1—8 • 67% of all observations are singletons (cows with calves
included)
Group type for multi-adult groupsG = 1.76, p = 0.18
Month; LS Means
Vertical bars denote 0.95 confidence intervals
1 2 3 4 5 6 7 8 9 10 11 12
Month
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
Gro
up s
ize
F = 4.68, p < 0.0001
Open Closed
Season Mean SD Mean SD t P(1-tailed)
Spring 1.89 1.33 1.79 1.14 -0.69 0.25
Summer 1.42 1.20 1.45 1.09 0.18 0.43
Fall 1.68 1.83 1.47 1.07 -1.67 0.048
Winter 1.74 1.05 1.44 0.89 -2.55 0.0055
Group size by habitat closure by season (α’ = 0.0127)
Are the sexes distributed differently across the landscape?
• Create 2041 random points within the park
• Compare with 2041 observations of adults
• Tested moose locations vs. random locations– Dispersion significantly different (p < 0.0001)
• Tested males vs. females seasonally– Šidák correction for multiple comparisons: α’ =
0.0127– Winter (21 Oct.—30 Apr.) p < 0.0001 – Spring (1 May—30 June) p = 0.011– Summer (1 July—20 Sept.) p = 0.005– Rut (21 Sept.—20 Oct.) p = 0.35
Are the sexes distributed differently across the landscape?
Social segregation
• Measured by social segregation coefficient– Varies from 0 (complete aggregation) to 1
(complete segregation)
What habitat characteristics are driving the segregation of the sexes?
• Classify observations by habitat characteristics• Account for potential location error
Forest
Meadow
100 m
• Classify observations by habitat characteristics• Account for potential location error• Characterize random points in the same manner
to represent available habitat• Randomly assign a sex to each random point• Use stepwise logistic regression to identify
factors influencing space use
What habitat characteristics are driving the segregation of the sexes?
Possible predictors
Landscape metrics• Distance to road• Distance to village• Distance to arable land• Distance to railway• Distance to forest edge• Distance to marsh/water
• Group size in Biebrza moose is small• Group size in open habitats is greater than in closed habitats,
particularly in winter• Mixed-sex groups are not common, males and females are equally
solitary• Moose in Biebrza segregate outside of the breeding season on a
very fine scale• In general, open habitats were avoided and forested habitats were
selected• Males have a higher preference for deciduous forest in winter and
summer and are farther from roads• Females have a higher preference for coniferous forest in winter
and are closer to roads• Females use coniferous forest more in winter than do males• Marsh habitat, although generally avoided, is very important during