Social structure and habitat preferences of moose population in Biebrza National Park

1. 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 Project: Biodiversity protection of Red Bog (Czerwone Bagno) - relic of raised bogs in Central Europe

2. Biebrza National Park

3. Biebrza Moose Data • Observations by park personnel • group size and composition • location • date • 1998-2010 (most from Sept. 2006-February2010) • 1534 observations • 2770 total moose • Classified as adult male, adult female, juvenile, or calf • 2041 adults of known sex

5. 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

6. 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)

9. Group type for multi-adult groupsG = 1.76, p = 0.18

11. F = 4.68, p < 0.0001

13. Group size by habitat closure by season (α’ = 0.0127)

14. Are the sexes distributed differently across the landscape? • Create 2041 random points within the park • Compare with 2041 observations of adults

15. Are the sexes distributed differently across the landscape? • 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

16. Social segregation • Measured by social segregation coefficient • Varies from 0 (complete aggregation) to 1 (complete segregation)

17. What habitat characteristics are driving the segregation of the sexes? • Classify observations by habitat characteristics • Account for potential location error

18. Forest 100 m Meadow

19. What habitat characteristics are driving the segregation of the sexes? • 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

20. Possible predictors Landscape metrics Habitat metrics Deciduous forest Coniferous forest Other forest Marsh Meadow Arable land/orchard Wetland (yes/no) Edge (yes/no) • Distance to road • Distance to village • Distance to arable land • Distance to railway • Distance to forest edge • Distance to marsh/water • Year • Season Temporal metrics

21. How do moose respond to those factors? Selection coefficients • = (use – availability)/(use + availability) • – 1 (complete avoidance) to +1 (complete preference)

22. Habitat selection * * * * * Males ≠ females

23. * * * * * * * *Males ≠ females

24. Importance of marsh to calving • 16 May-15 June • 90% of all female locations in marsh • 50% of all male locations in marsh (40% in deciduous forest) Use

25. Selection during calving

26. What patterns are there in space use that could lead to segregation? • Use variables identified by logistic regression • Test sex × location (random vs. observed) • Test sex × season × location

27. observed random F M F M deciduous coniferous

28. observed random F M Distance to road calving breeding calving breeding winter winter summer summer

29. observed random F M coniferous forest calving calving breeding breeding winter winter summer summer

30. observed random F M deciduous forest calving calving breeding breeding winter winter summer summer

31. observed random Distance to forest edge M F calving calving breeding breeding winter winter summer summer

32. Conclusions • 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 the calving season

33. Thankyou