Development of Robust Bird-based Climate Change Indicator

Science Center Objects

The Challenge: Appropriate ecological indicators of climate change can be used to measure concurrent changes in ecological systems, inform management decisions, and project the consequences of climate change. Breeding bird distributions are predicted to be sensitive to changes in climate, and could be useful climate-change indicators. We seek to develop robust bird-based, climate-change indicators using data from the North American Breeding Bird Survey (BBS), a geographically and temporally (1966 – present) extensive data set on breeding bird distributions in North America.

The Science: Imperfect detection and use of static species distributionmodels challenge the development of reliable indicators from BBS data. Imperfect detection may obscure biological processes behind observation error, while static models assume that current relationships between climate and species distributions reflect long-term equilibria, an unlikely scenario. Using dynamic, correlated-detection occupancy models, recently developed by colleagues at USGS-PWRC, we will estimate the probability of species presence across their ranges. Correlated detection models can estimate detection probabilities from spatially replicated surveys. Furthermore, these dynamic models estimate transition probabilities, which allow projections for species that are not in equilibrium (Figs. 2 & 3).

The Future: Over the next year, building on the work of Clement and others (2016; Global Change Biology 22:3273-3285), we will estimate a suite of avian population distribution parameters and evaluate their utility for developing indicators of climate change. Such indicators can be used to track changes in species distributions and to test hypotheses about the effects of climate change. For example, changes in range size or boundaries in successive years can provide a metric reflecting expansions or contractions in range size over time in response to climate change. Other ecological hypotheses predict increases in rates of local colonization at northern edges of species ranges and increased local extinction at the southern edges of species ranges. The current work can also be used to test additional hypotheses that predict that the effect of climate change on the size, location, and dynamics of ranges will depend on the ecological niches of different species.