1. Linking spatial and temporal patterns in resource availability, individual performance, & population dynamics.

2. Primary thesis objectives Determine how much individual detail is needed in models of population dynamics. Relate explicitly spatial and temporal variation in resource abundance to individual “success”.

3. For today…. Population level dynamics of red squirrels in Kluane valley Temporal/spatial variation in resource abundance and territory sizes Red Squirrel (Tamiasciuris hudsonicus)

4. Population dynamics

5. 1. Population dynamics: –Holistic approach assumes: Habitat is homogeneous All individuals are identical –Reductionist approach assumes: individual level of detail is important Go with Holistic View - for now

6. Midden locations 60 m

7. SU KL

8. Female densities

9. Population models 4 competing models Density independent: N t+1 = N t e a Density dependent: N t+1 = N t e a+bNt Delayed density dependent: N t+1 = N t e a+bNt+cNt-1 Response Surface model: N t+1 = N t e a+bNt+cNt-1+dNt 2 +eNt-1 2 +fNtNt-1 AICc used to compare model fit to data

10. Population models: AICc results

11. Population models: Density dependence?? SU

12. What about food?? KL

13. Population summary Food and density effects appear to differ between these ‘populations’ KL - Density independent/Density dependent SU - Density dependent Habitat quality too???

14. Why are they different? Different birth rates, survival patterns? – λ-contribution analysis (λ=e r ) which life-history characteristic best-tracks changes in population growth-rate? »begin to tease apart what life-history is related to changes in the population growth rate (ie. fecundity, survival) »also, investigate spatial variation in this “key-factor” within each population, and relate to territory ‘quality’

16. CONES AND TERRITORY SIZE

17. Annual cone production White spruce - a masting species Cone index - count top 3m of tree Cone calibration - count all cones!! 3m Actual cone range: 1 - 2774 y=1.185*x r 2 =0.996

18. ***** Spruce Cones 198819901992199419961998 2000 0 50 100 150 200 250 300 350

19. *****

20. Methods: - individual squirrels visually observed - territorial behaviours & locations noted - 100 % MCP 60 m 1994 and 2001 Territory size

21. Temporal patterns *****

22. *****

23. Linking food availability to reproductive output

24. Number of offspring per female per year. ANOVA P > 0.05 NS *****

25. Number of squirrels weaned per female per year. ANOVA P < 0.001 *****

26. Number of squirrels born surviving to one year. ANOVA P < 0.001 *****

27. Territory size decreases after a mast year, otherwise size appears mostly constant No significant effect of resource fluctuations on litter size, BUT significant effect on juvenile survival to weaning, 1-yr Territory Size - temporal summary

28. Recall: assumption of spatial homogeneity IS IT?

29. Spatial vegetation patterns Vegetation transects every 60m - 3 transects 120 0, 240 0, 360 0 - each transect 4m x 25m Kriged surfaces based on transects (10m 2 cell size) - ws density - ws density >5cm dbh, alive - bark beetle killed trees - aspen - willow

30. 60 m Total white spruce density

31. 60 m Midden placement (total ws den)

32. 60 m White spruce (>5cm dbh, alive) density

33. 60 m Bark beetle killed spruce density

34. 60 m Aspen density

35. 60 m Willow density

36. Spatial patterns in territory size

37. 60 m White spruce (>5cm dbh, alive) density and August 2002 territories

38. 60 m White spruce (>5cm dbh, alive) density, June and August territories

39. 60 m 123 110 170 84 166 579 293 399 139 120 286 95 58 28 41 101 333 57 579 258 429 700 310 652 735 175 400 248 1034 143 122 70 119 40 90 Number of white spruce (>5cm dbh) and August territories

40. Spatial patterns in cone production IS IT SPATIALLY HOMOGENEOUS??? Additional cone count trees established in 2002 Modelling cone production - independent variables: dbh, density of surrounding trees, dbh of surrounding trees, location (r 2 = 0.38) plus.. slope, aspect, height, basal light class (r 2 = 0.60)

41. Cone Production 2002

42. Cone Production 2003

43. p<0.05 Change in June territory size 2002-03

44. Goal - to map variation in habitat quality = c c c c c c +

45. Continuing Objectives Continue to develop cone production models Link spatial and temporal cone availabity and territory size to territory quality & “success” Investigate individual contributions to overall population dynamics

46. Long-Term Food Add Thoughts What happens to territory size when under constant high food conditions? Will females maintain high reproductive output under high food? What’s the key factor for recruitment? (What is the effect of lack of cues for increased cone production?)

49. Summer 2002 – field methods 1. Territory mapping

50. Population growth rate

51. NS paired t-test June and August 2002 territory sizes. (paired data only)

52. ** Changes in an individual’s territory size