Variation in Bird Nests Between Southern Ontario and Northern Manitoba. Carla A. Crossman, Vanya G. Rohwer, and Paul R. Martin

Transcription

1 Variation in Bird Nests Between Southern Ontario and Northern Manitoba Carla A. Crossman, Vanya G. Rohwer, and Paul R. Martin

2 Geographic Variation

3 Local Adaptation the same form or similar forms occur in similar environments in a number of different species, especially in unrelated species (due to convergence) West-Eberhard 1992

4 Nests are Important Huge investment House eggs and young Act as a buffer Conserve energy

5 Nests are Diverse

6 Previous Studies Few studies Some evidence of variation Focused on single species

7 Study Sites Churchill, Manitoba (Northern Manitoba) Elgin, Ontario (Southern Ontario)

8 Study Species

9 Study Species American Robin (Turdus migratorius)

10 Study Species American Robin (Turdus migratorius) Savannah Sparrow (Passerculus sandwichensis)

11 Study Species American Robin (Turdus migratorius) Savannah Sparrow (Passerculus sandwichensis) Yellow Warbler (Dendroica petechia)

12 Study Species American Robin (Turdus migratorius) Savannah Sparrow (Passerculus sandwichensis) Yellow Warbler (Dendroica petechia) American Goldfinch (Carduelis tristis) Common Redpoll (Carduelis flammea)

13 Study Species American Robin (Turdus migratorius) But Carla Savannah Sparrow (Passerculus sandwichensis) Yellow Warbler (Dendroica petechia) American Goldfinch (Carduelis tristis) Common Redpoll (Carduelis flammea) Goldfinches and Redpolls are 2 different species!!!

14 Study Species American Robin (Turdus migratorius) Savannah Sparrow (Passerculus sandwichensis) Yellow Warbler (Dendroica petechia) American Goldfinch (Carduelis tristis) Common Redpoll (Carduelis flammea)

15 Study Questions Does variation in bird nests exist between Churchill, Manitoba and Southern Ontario? If so How is variation achieved? How does this compare across species?

16 Data Collection Nest Wall Thickness (mm) Nest Collection (n=5) Nest Mass (g)

17 Nest Composition

18 Churchill Elgin

19 Results * * * * * * p <0.05

20 Results * But Carla What about changes in body/clutch size? * * * * * p <0.05

21 Results * * * * * * p <0.05

22 Mass (g) 240 American Robin Mass (g) 8 Savannah Sparrow Mass (g) * Carduelis * Mass (g) * Yellow Warbler * * *

23 Main Findings Nests were heavier in Churchill vs. Elgin Nests had heavier nest walls in Churchill vs. Elgin Each species achieved this in a different way Savannah Sparrows were different

24 Main Findings Nests were heavier in Churchill vs. Elgin But Carla Nests had heavier nest walls in Churchill vs. Elgin You had a sample size of 5 Each species achieved this in a different way Savannah Sparrows were different

25 Main Findings Nests were heavier in Churchill vs. Elgin Nests had heavier nest walls in Churchill vs. Elgin Each species achieved this in a different way Savannah Sparrows were different

26 Possible Mechanisms

27 Possible Mechanisms But Carla Its flippin cold up north, and warmer down south It s obviously temperature

28 Climate Possible Mechanisms

29 Possible Mechanisms Climate Predation

30 Possible Mechanisms Climate Predation Parasitism

31 Possible Mechanisms Climate Predation Parasitism Life History Strategies

32 Savannah Sparrows But Carla What s up with Savannah Sparrows?

33 Savannah Sparrows Ground Nest Above-Ground Nest

34 Main Findings A common set of selective pressures within each site selects for variation in nests

35 Acknowledgements Vanya Rohwer Dr. Paul Martin Queen s University Biological Station R. Barcarse, M. Conboy, S. Jones, S. Machler, and D. Moore Churchill Northern Study Centre (Northern Research Fund)