Rimmer, C. C., Vermont Center for Ecostudies, Norwich, Vermont, USA, crimmer@vtecostudies.org; Hart, J. A., Vermont Center for Ecostudies, Norwich, Vermont, USA, jhart@vtecostudies.org; Dettmers, R. P., U.S. Fish and Wildlife Service, Hadley, Maasachusetts, USA, Randy_Dettmers@fws.gov; Whittam, B., Bird Studies Canada, Sackville, New Brunswick, Canada, bwhittam@bsc-eoc.org; McFarland, K. P., Vermont Center for Ecostudies, Norwich, Vermont, USA, kmcfarland@vtecostudies.org; Aubry, Y., Canadian Wildlife Service, Ste. Foy, Québec, Canada, Yves.Aubry@ec.gc.ca Abstract: Bicknell’s Thrush is among the Nearctic-Neotropical migrants of highest conservation priority in North America. Its rarity (estimated global population of < 50,000 individuals), restricted breeding and winter distributions, habitat specialization, and vulnerability to multiple rangewide threats are compounded by incomplete knowledge about its overall status. The species exhibits a complex mating system and a highly skewed breeding adult sex ratio. Sexual habitat segregation may occur in winter, and females appear to be limited at some point in the annual cycle. Recent population trend data show conflicting results, with sharply declining populations in Maritime Canada and stable or slightly increasing trends in the U.S. On the species’ Greater Antillean wintering grounds, where an estimated 90% of the global population occurs on Hispaniola, loss of forested habitats has been severe and is ongoing. The International Bicknell’s Thrush Conservation Group (IBTCG) formed in 2007 to develop and implement a scientifically-based conservation action plan for the species. We will present an overview of the conservation challenges facing Bicknell’s Thrush, highlight the IBTCG’s primary goals and recommendations, and assess the prospects for this at-risk species.

3. Partners In Flight = North America Watch List IUCN Red List = Vulnerable ABC/Audubon WatchList = Red List Canada = Candidate for Federal Listing USFWS = Special Concern ME, NH, NY, VT = Special Concern www.bicknellsthrush.org

4. George J. Wallace c. 1935 Eugene P. Bicknell c. 1881

5. The New Generation of BITHnologists Henri R. Ouellet, 1995

6. BITH Migratory Range “ Islands” north and south Migration routes/patterns = ??

7. Bicknell’s Thrush Distribution in the U.S. 5 km² 263 km² 88 km² 496 km² 261 km²

9. Threats to Breeding Habitats

10. “ Only a freak ornithologist would think of leaving the trails for more than a few feet.” George J. Wallace, 1936

12. BITH habitat declines sharply with rising temperature 0 20 40 60 80 100 120 140 160 +0 +1 +2 +3 +4 +5 +6 +7 Mean July Temp. Change (°C ) Relative to 1950-1980 BITH Habitat (1,000 ha) Low emissions 2.8°C High emissions 5.9°C

13. Complex Breeding System Polygynandry: Both males and females mate with multiple partners; paternity is highly mixed Nesting Female Male Home Range r r r r r

14. n=4 n=4 n=10 n=3 n=5 n=7 Overall mean = 2.2 males : female Breeding Adult Sex Ratios

15. Hispaniola: winter stronghold of BITH Dominican Republic Haiti DR: ~10% original forest remains Haiti: 1-2% original forest left

16. Limiting Factors in Winter Habitats

17. % Unprotected Wet Broadleaf Forest 65.9 Dense Conifer Forest 39.3 Semi-humid Broadleaf Forest 75.9

18. Strong evidence that females are limited during annual cycle When and where?

19. Where are Females Limited? Nest 1:1 sex ratio in clutch Fledge Post Fledging Dispersal 1:1 1:1 Fall Migration 1:1 ? 1:1 ? Ratio ? Spring Migration Ratio ? Breeding Grounds >2:1 Cloud Forest >1:1 Rain Forest <1:1 Habitat and Territory Selection

20. What do we know about BITH populations?

21. Bicknell’s Thrush in the White Mountains: 7% Annual Decline 9 Years 17 Routes 2002-2008 declines in Canada: New Brunswick – 20%, Nova Scotia – 19%

22. BITH relative abundance on U.S. routes surveyed annually, 2001-2008

23. www.bicknellsthrush.org/ International Bicknell’s Thrush Conservation Group (IBTCG) www.bicknellsthrush.org Developing a Conservation Action Plan

24. IBTCG structure: inclusive, flexible Breeding and Migration Research Breeding and Migration Forestry Wintering Grounds Coordination Committee Breeding and Migration Monitoring

25. Over-winter Survival Fecundity Autumn Migratory Survival & Seasonal Interactions Spring Migratory Survival & Seasonal Interactions Winter Habitat Amount/quality Direct Mortality Physiological Condition Introduced Predators More Catastrophic Weather Atmospheric Phenomenon (Hg, Pb, Acid Rain) Climate Change Increased Drought & Wind Natural Fires Subsistence Farming & Logging Disease, Parasites, etc. Feral Domestic Animals Human-caused Fires Low Genetic Diversity Breeding Habitat Amount/quality Direct Mortality Breeding Season Survival + Physiological Condition Atmospheric Phenomenon (Hg, Pb, Acid Rain) Climate Change Cone-Squirrel Cycle Disruption Forest Conversion Increased Rain & Wind Forestry Practices Incidental Take Forest Succession Male-biased Sex Ratio Human Disturbance Industrial Development Disease, Parasites, etc. Coastal Development Δ in Prey Emergence Forest Pathogens

26. Over-winter Survival Fecundity Autumn Migratory Survival & Seasonal Interactions Spring Migratory Survival & Seasonal Interactions Amount of Winter Habitat Direct Mortality Physiological Condition Amount of Breeding Habitat Direct Mortality Breeding Season Survival + Physiological Condition Track effects of climate change ID Important Migratory Sites Determine Forestry Effects Assess Effects of Acid Deposition Monitor Responses to Development Track effects of climate change Develop Forest Mgmt Guidelines and Habitat Supply Analysis ID Where Deforestation is Occurring Prioritize Remaining Forest for Protection Habitat Use and Survival Relative to Land Use and Condition Protection & Restoration of Key Habitats

28. Wintering Grounds Conservation Actions Protect, restore, and manage current and potential winter habitat Investigate overwinter survival and demography relative to local habitat condition and quality (connectivity, seasonal carry-over effects) Expand resources and reach of BITH Habitat Protection Fund Clarify BITH distribution and habitat use on other Greater Antillean islands Involve and build capacity of in-country partners