This study examines the potential population-level impacts of climate change on Bicknell's Thrush, a vulnerable montane forest songbird. Using occupancy models, the researchers predict that a 1°C increase in mean July temperature would reduce available Bicknell's Thrush habitat by 67%, fragmenting it into fewer (29 vs. 128) and larger patches. This loss of habitat is expected to decrease the species' occupancy, colonization rates, and increase extinction rates. While some persistence may be possible in remaining high quality habitat patches under small amounts of warming, the authors conclude that over 1°C of warming could threaten the long-term persistence of Bicknell's Thrush in Vermont.

1. Population-level implications for climate change for a montane forest songbird Sarah J K Frey Allan M Strong Kent P McFarland AOU 2009 Philadelphia

2. Mountains & Climate Change

4. Vulnerable to climate change

6. Fewer & smaller patches = HABITAT LOSS (Rodenhouse et al. 2008 Mitig Adapt Strateg Glob Change) Remaining habitat will likely change in quality (Beckage et al. 2008 PNAS) alteration of successional processes Predictions – Hypotheses

7. If this is happening, then BITH populations will have to respond in one of 3 ways Predictions – Hypotheses

8. Change their behavior (adapt to the new conditions) Predictions – Hypotheses

9. 2. Move to a new location (latitude or elevation) Predictions – Hypotheses

10. 3. Decline/go extinct Predictions – Hypotheses

11. Multi-season Occupancy Model (MacKenzie et al. 2003 Ecology) Population Parameters Occupancy  Colonization Detection  Extinction Methods - Model Between seasons Colonization or extinction 1,2,3 1,2,3 1,2,3 1,2,3 Surveys Seasons 1 2 3 4 Occupancy & detection Within seasons

12. Habitat Covariates Local = boreal basal area (BBA) (Beckage et al. 2008 PNAS) Landscape = patch size (Lambert et al. 2005 Wilson Bull) Methods - Model

13. Climcalc(http://www.pnet.sr.unh.edu/climcalc/) Mean July Temp (MJT) calculated - lat, long, elv, slp, asp Current MJT envelope for BITH habitat Methods – Landscape Climate Data

14. Landscape: + 1° C to MJT envelope Local (BBA): MJT inc. over time (amnt. of time for 1° C inc. = 7 yrs.) Northeast Climate Data (www.northeastclimatedata.org) A1 Scenario Methods – Warming Predictions

15. Current & future (+1°C) maps of predicted habitat amount (landscape) & suitability (patch) Compared amount and quality of habitat Estimated occupancy, colonization, and extinction now and with 1°C of warming Methods – Population Predictions

16. Occupancy (Boreal Basal Area * Patch Size) Colonization (Boreal Basal Area) Extinction (Boreal Basal Area + Patch Size) Detection (Survey + Patch Size) Methods - Model

17. No time lag – once pixel moves out of MJT envelope, it is no longer available as habitat Boreal basal area is a good indicator of local habitat quality Beckage et al. 2008 model realistically represents changes in the composition of local habitat over time Lambert et al. 2005 model is a realistic representation of current potential habitat availability at the landscape scale Model Assumptions

18. Results - Landscape # of patches decreased from 128 to 29 Total amount of habitat reduced by 67%

19. Results - Landscape # of patches decreased from 128 to 29 Total amount of habitat reduced by 67%

20. Results - Local Avg. patch size increased 44.6% (90.5 to 130.8 ha) Remaining patches = higher quality BBA 29.1 - 60.6 m2/ha Total BBA decreased 31.3%

21. Results - Local Avg. patch size increased 44.6% (90.5 to 130.8 ha) Remaining patches = higher quality BBA 29.1 - 60.6 m2/ha Total BBA/patch decreased 31.3%

22. Results - Population parameters occupancy colonization

23. Results - Occupancy Current

24. Results - Occupancy +1OC

25. Results - Colonization Current

26. Results - Colonization +1OC

27. Colonization least influenced by changes in landscape scale features, although total area available for colonization decreased by 66.8% Results - Population parameters

28. Results - Extinction Current

29. Results - Extinction +1OC

30. Population implications are primarily related to the total amount of habitat lost Composition of montane patches altered – less so than overall amount of habitat Loss of lower elevation sites likely has less of an impact - represent marginal habitat (?) Conclusions

31. Under small amounts of warming, Bicknell’s Thrush may be able to persist in the remaining high quality patches > 1°C of warming may call into question the long term persistence of this species in Vermont Conclusions

32. Landscape - Increased Warming

33. Landscape - Increased Warming

34. Landscape - Increased Warming

35. Hope for Bicknell’s ?

36. 70+ year dataset on Mt. Washington (NH) shows that warming at high elevations may be occurring at a slower rate than at lower elevations (Seidel et al. 2009 Arctic, Antarctic, and Alpine Research) Hope for Bicknell’s?

38. Juliette Juillerat

39. HéctorSlongo

40. Katie Pindell

41. Oregon State University

42. Bett’s Landscape Ecology Lab