Investigating Relationships between Landbird Demographics and Climate/Weather

Climate and weather have strong influences on avian population dynamics, affecting both reproductive success and annual survival.  Such influences can affect birds during the breeding season, on the wintering grounds, or during migration.  Short term annual variation in seasonal precipitation, for example, may influence the potential reproductive success of a local breeding population.  In the longer term climate shift will cause corresponding shifts in the geographic range of a species by altering the spatial distribution of tolerable ranges of environmental factors, which in turn determine the spatial distribution of breeding, stopover, or overwintering habitat.  Increasingly we find that MAPS data reveals such relationships.

Climate research is a growing interest at IBP.  In 2002 we researched the effects of two major ocean-atmosphere phenomena, the El-Nino Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO), on avian demographics among 31 species that breed in national forests of the Pacific Northwest.  These studies revealed that annual variation in both oceanic oscillations explained between 50 and 90% of annual variation in reproductive success of the 31 species.  For Neotropical migrants ENSO-driven pre-spring migration conditions in Western Mexico correlated highly with subsequent reproductive success.  For resident and short-distance migrants reproductive success was a function of NAO-driven conditions on the breeding grounds in Washington and Oregon.  This research resulted in the following publication:

Nott, M.P., DeSante, D.F., Siegel, R.B., and P. Pyle. 2002. Influences of the El Niño/Southern Oscillation and the North Atlantic Oscillation on avian productivity in forests of the Pacific Northwest of North America. Global Ecology and Biogeography 11:333-342. (summarized here)

Nott (2002) also reported on the effects of weather (and landscape) on landbird survival and reproductive success but used data collected in Texas in Texas.  In this study, we related annual indices of reproductive success and apparent annual survival rates to seasonal climate indices, and also to Texas-wide temperature and precipitation data. We then related station- and species-specific indices of reproductive success, counts of adults and young, and several estimates of avian diversity to landscape variables obtained from analyses of 1-kilometer radii National Land Cover Data maps surrounding each station. PDF (10MB).

Evidence of strong relationships between spatio-temporal patterns in avian demographics and corresponding patterns of climate and weather is accumulating.  Analyses of a subset of data from the Pacific Northwest study (Nott et al. 2005) revealed strong regional-scale relationships between two oceanic influences and annual productivity (Nott et al. 2002).  More recently techniques were developed for detecting finer-scaled relationships using data from the Global Precipitation Climatology Project (GPCP), and the Normalized Difference Vegetation Index.

A small report exemplifies seasonal patterns of precipitation (GPCP) associated with the 2.5 degree blocks that banding locations (DoD installations) lie within.  These data have been used to model MAPS data towards resolving temporal patterns in demographics and elucidating migration connectivity networks (manuscript in prep.):

Nott, M. P. and N. Michel. 2006. Management strategies for reversing declines in landbirds of conservation concern on military installations: Enhanced species-landscape models of avian demographics. The Institute for Bird Populations, Pt. Reyes Station, CA. A report to the Legacy Resources Management Office, Washington. D.C.. PDF (1.47MB)

[BACK]

This page was last updated 12/29/2006