Multidirectional abundance shifts among North American birds and the relative influence of multifaceted climate factors

Abstract

Shifts in species distributions are major fingerprint of climate change. Examining changes in species abundance structures at a continental scale enables robust evaluation of climate change influences, but few studies have conducted these evaluations due to limited data and methodological constraints. In this study, we estimate temporal changes in abundance from North American Breeding Bird Survey data at the scale of physiographic strata to examine the relative influence of different components of climatic factors and evaluate the hypothesis that shifting species distributions are multidirectional in resident bird species in North America.We quantify the direction and velocity of the abundance shifts of 57 permanent resident birds over 44 years using a centroid analysis. For species with significant abundance shifts in the centroid analysis, we conduct a more intensive correlative analysis to identify climate components most strongly associated with composite change of abundance within strata. Our analysis focus on two contrasts: the relative importance of climate extremes vs. averages, and of temperature vs. precipitation in strength of association with abundance change. Our study shows that 36 species had significant abundance shifts over the study period. The average velocity of the centroid is 5.89 kmÁyr À1 . The shifted distance on average covers 259 km, 9% of range extent. Our results strongly suggest that the climate change fingerprint in studied avian distributions is multidirectional. Among 6 directions with significant abundance shifts, the northwestward shift was observed in the largest number of species (n = 13). The temperature/average climate model consistently has greater predictive ability than the precipitation/extreme climate model in explaining strata-level abundance change. Our study shows heterogeneous avian responses to recent environmental changes. It highlights needs for more species-specific approaches to examine contributing factors to recent distributional changes and for comprehensive conservation planning for climate change adaptation. K E Y W O R D Sabundance shift, bird, breeding bird survey, climate change fingerprint, climate change metrics, climate change velocity, density shift, multidirectional distribution shift --

Differential winter and breeding range shifts: Implications for avian migration distances

“…Westward shifts were common; 37.6% of the species had significant westward longitude shifts in their breeding COA. Our results are consistent with two recent analyses of North American birds that also found high occurrences of avian abundances shifting west during the breeding season (Currie & Venne, ; Huang et al, ). Additionally, Fei et al () examined 86 tree species across the eastern United States and most commonly observed westward range shifts over the course of 30 years.…”

“…Recent literature emphasizes species‐specific multidirectional shifts in distributions (Currie & Venne, ; Fei et al, ; Gillings, Balmer, & Fuller, ; Huang et al, ; VanDerWal et al, ). Complex interactions between temperature and precipitation are driving species‐specific responses to changes in climate (Garcia, Cabeza, Rahbek, & Araújo, ; Tingley, Koo, Moritz, Rush, & Beissinger, ; Tingley et al, ; VanDerWal et al, ).…”

“…Multidirectional shifts—shifts having a latitude and longitude component—can be evaluated by incorporating measures of central tendency of a species range. Using central tendency measures, multidirectional shifts have been documented in North America and Europe for various birds, trees and plant species (Ash, Givnish, & Waller, ; Currie & Venne, ; Fei et al, ; Huang, Sauer, & Dubayah, ; Pavón‐Jordán et al, 2019).…”

“…We expect that winter COA shifts will occur more rapidly northward than their breeding range counterparts. Our expectations are derived from recent studies of North American Birds which have documented northward winter range expansion (La Sorte & Thompson, ) but more species‐specific variability of movements in the breeding season (Currie & Venne, ; Huang et al, ). Second, we test the hypothesis that the distance between winter and breeding COAs has not changed; therefore, migration distances have been unaffected.…”

Patterns and mechanisms of heterogeneous breeding distribution shifts of North American migratory birds

“…Our results highlight that distributional responses to global change are highly variable, and that southward shifts are a possible strategy for coping with change, despite a lack of hypotheses in the literature predicting southward shifts. Our results that 55% of centroid shifts were northward and 44% of shifts were southward are similar to other multispecies studies of distribution shifts (Zuckerberg et al , Currie and Venne , Huang et al ). We did not find strong predictors of southward shifts in breeding distribution centroid, similar to other studies that have shown southward shifts in distributions without clear evidence of an effect of life history (Zuckerberg et al ).…”