Search USGS⌕ Search

USGS · 5224291

Sexual selection affects local extinction and turnover in bird communities

Abstract

Predicting extinction risks has become a central goal for conservation and evolutionary biologists interested in population and community dynamics. Several factors have been put forward to explain risks of extinction, including ecological and life history characteristics of individuals. For instance, factors that affect the balance between natality and mortality can have profound effects on population persistence. Sexual selection has been identified as one such factor. Populations under strong sexual selection experience a number of costs ranging from increased predation and parasitism to enhanced sensitivity to environmental and demographic stochasticity. These findings have led to the prediction that local extinction rates should be higher for species/populations with intense sexual selection. We tested this prediction by analyzing the dynamics of natural bird communities at a continental scale over a period of 21 years (1975-1996), using relevant statistical tools. In agreement with the theoretical prediction, we found that sexual selection increased risks of local extinction (dichromatic birds had on average a 23% higher local extinction rate than monochromatic species). However, despite higher local extinction probabilities, the number of dichromatic species did not decrease over the period considered in this study. This pattern was caused by higher local turnover rates of dichromatic species, resulting in relatively stable communities for both groups of species. Our results suggest that these communities function as metacommunities, with frequent local extinctions followed by colonization. Anthropogenic factors impeding dispersal might therefore have a significant impact on the global persistence of sexually selected species.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Paul F. Doherty, G. Sorci, J. Andrew Royle, J.E. Hines, J.D. Nichols, T. Boulinier. 2003-04-07. Sexual selection affects local extinction and turnover in bird communities. https://doi.org/10.1073/pnas.0836953100

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

The scope and severity of bat fatalities at US wind energy facilities

Wind turbines are a major source of bat fatalities in the United States, yet the magnitude and species-specific patterns of these fatalities have remained poorly quantified because monitoring has been site-specific, unstandardized, and not designed for landscape-level synthesis. In the most comprehensive analysis to date, we synthesized 499 post-construction monitoring reports and developed a multi-species Bayesian hierarchical framework with an adapted N-mixture model to pool information across sites and estimate total fatalities for ten bat species across the conterminous United States from 1981-2024. Our analysis predicts approximately 18.7 million bat fatalities over this period, with substantially higher species-specific totals than previously estimated. Our framework provides the first landscape-level analysis that can predict fatalities for unmonitored locations and years, identify landscape-level drivers of fatalities, produce a multi-decade hindcast of cumulative losses due to wind energy, and map where species-specific risk is highest. Although limitations and uncertainty remain, the magnitude of predicted fatalities may be comparable to total losses from white-nose syndrome, another major threat to North American bat populations. These threats affect largely different species, suggesting their impacts may compound, but updated population-level impact assessments could reveal potential cumulative effects. Our estimates of species-specific covariate relationships with rotor-swept area, ground clearance, land cover, and proximity to rivers, highlight opportunities to help reduce impacts through wind turbine design and siting. This work establishes a generalizable landscape-level framework for evaluating wildlife fatalities at wind energy facilities and highlights how coordinated monitoring, data sharing, and population-level impact assessments could further inform conservation efforts.

conterminous United States↗

Extensive glacier loss in the coterminous United States

Glaciers populate the mountain ranges of the western conterminous United States and despite their importance to alpine hydrology, their area and volume change have never been comprehensively evaluated. Since the mid-Twentieth Century about one-quarter of the glaciers have disappeared and the overall area and volume are reduced by one-third. The pattern of glacier shrinkage suggests most glaciers in the Conterminous US are largely maintained by local topographic influences due to their small size. These results are critical to understanding evolving high alpine hydrology and important to ecosystem processes.

conterminous United States↗

Oak masting breaks down in a highly fragmented, pollen limited landscape

Masting, the production of variable and synchronous seed crops, is common among wind pollinated trees, and periodic pollen limitation is thought to be an important component of the process of masting. However, little is known either about the dynamics of mast seed production or pollen limitation in isolated trees. We tracked seed production of valley oak ( Quercus lobata ) over 11 years in a highly fragmented landscape in California’s Central Valley in which many trees lacked conspecific neighbors within 500 m. We found that oaks with closer neighbors produced more acorns on average than oaks with fewer neighbors. Consistent with theories linking mast seeding and pollination, the isolation effect was most apparent in the highest seed production years. While individual trees showed substantial interannual variation in seed production, we observed little synchrony in seed production among individuals compared to intact oak populations throughout California. Our results indicate that highly fragmented populations suffer signs of pollen limitation and do not produce synchronous seed crops. Fragmentation, alongside climate change, is a dimension of global change that interrupts the typical seed production dynamics of trees.

California↗