Ecology and Conservation of Spruce-Fir Birds
Identifying Climate Change Refugia
As a postdoc at UMass I am working on identifying forest refugia for spruce-fir obligate bird species in the face of ongoing climate warming. Collaborators on this project are developing forest models that describe the distribution and structure of spruce-fir forests currently and into the future under various climate change and disturbance scenarios. I combine these forest structure models with bird occurrence data to develop habitat selection and distribution models for spruce fir obligate species. I also use nesting data for focal species to model nesting phenology and reproductive success as functions of forest structure and composition. Bird distributions and demographic parameters will then be modeled into the future, and refugia will be identified as areas where species richness and reproductive success remain high.
Collaborators: Dave King (UMass), Tony D'Amato (U of Minnesota), Jane Foster (U of Minnesota), Aaron Weiskittel (U of Maine) |
Regional Population Trends
Spruce-fir birds are underrepresented in continent-scale monitoring programs due to the inaccessibility of the habitat. Long term population trends in spruce-fir birds are therefore poorly understood and, for many species, are yet to be examined on a broad geographic scale. I combine point count data from 16 local and regional survey programs in the eastern United States, controlling for the effects of survey protocol in the estimation of detection probabilities and abundance, to analyze population trends at multiple spatial scales for 14 spruce-fir species. Six species show overall significant declines, including Evening Grosbeak, Olive-sided Flycatcher, Yellow-bellied Flycathcer, and Bicknell’s Thrush which each show significant overall declines, and did not significantly increase at any individual survey. Spruce-fir obligate species, those that utilize only spruce-fir habitat, were more likely to significantly decline than species that use spruce-fir in addition to other habitat types.
Collaborators: Dave King, Bill DeLuca (UMass), Gerald Niemi (U Minnesota Duluth), Michale Glennon (Wildlife Conservation Society), Judith Scarl (Vermont Center for Ecostudies), Dan Lambert (High Branch Conservation Services) |
Habitat Selection and Community Composition
Spruce-fir bird community composition varies slightly across sites and across an elevation gradient. Determining what aspects of the local environment drive species occurrences will be important to accurately predict community responses to climate change or habitat disturbances. Collaborators and I are working to quantify forest structure at a number of low and high elevation spruce-fir sites across northeastern North America, and determine how these factors influence community composition.
Collaborators: Sara Scanga (Utica College), Jeremy Kirchman (New York State Museum), Alyssa Fitzgerald (U at Albany) |
Occupancy of Red Squirrels Across Elevational Gradients
Evidence suggests red squirrels in high elevation spruce-fir forest experience major biannual fluctuations in abundance in response to availability of spruce and fir cone masts. In years with high squirrel abundance, bird nests are depredated at higher rates and reproductive success in birds decreases. It has been suggested that warming climates my decrease the periodicity of cone masts so that squirrels will become more consistently abundant at high elevations, adding increased pressure on an already threatened bird community. Toni Lyn Morelli and I are working to model squirrel occupancy across time and elevation to determine whether squirrels are shifting upslope and becoming more consistently abundant in high elevation forests.
Collaborators: Toni Lyn Morelli (Northeast Climate Science Center) |
Taxonomy, Status, and Habitat Association of Gray-cheeked Thrush in Newfoundland and Labrador
Gray-cheeked Thrush (Catharus minimus ) is listed as “vulnerable” in Newfoundland and Labrador and is experiencing unexplained precipitous declines. However, federal protection and recovery planning for Gray-cheeked Thrush has been inhibited by uncertain taxonomic boundaries between putative subspecies and the closely related Bicknell’s Thrush (Catharus bicknelli ), and a lack of current information on distribution, abundance, and habitat needs of this species. Collaborators and I are working to fill these gaps in knowledge by conducting phylogeographic and phylogenetic analyses in Catharus Thrushes, and quantifying Gray-cheeked Thrush occurrence and habitat use in Newfoundland and Labrador.
Collaborators: Alyssa Fitzgerald (U at Albany), Darroch Whitacker (Parks Canada), Jeremy Kirchman (New York State Museum), Ian Warkentin (Memorial University). |