Which are the phenologically flexible species? A case study with common passerine birds

Abstract

One of the most consensual ecological effects of the current climate warming is the alteration of the environmental timing of ecosystems. Phenological shifts, at different levels of food webs, are predicted to have major effects on species assemblages. Indeed it is unlikely that all species should be able to respond to the phenological shifts of their environment evenly. Yet questions remain about the specific traits that predict the ability of a species to track the temporal fluctuations of its environment. In this study, we use data from the French Constant Effort Site ringing program over a 20 years period (1989–2008) to estimate the ability of 20 common passerine species to adjust their breeding phenology to spring temperature variations. We show that the sensitivity of species breeding phenology to climate relates to species mean migration distance, species’ thermal and habitat niche breadth and brain mass. Species with the broadest ecological and thermal niches, the shortest mean migration distances and the largest brains were most able to adjust their breeding phenology to temperature variations. Our results thus identify long distance migrants and ecological specialists as species that could most suffer from the future expected climate change and suggests phenological adjustment as one possible mechanism underlying the replacement of specialist species by more generalist ones, the so called functional biotic homogenization.

Phenological Changes in the Southern Hemisphere

“…However, recently published studies from the northern hemisphere provide useful pointers for future investigations. Amongst passerines in France, for example, species with the broadest ecological and thermal niches, shortest mean migration distances and largest brains were most able to adjust their phenology, indicating that specialists and long distance migrants are more at risk [84]. The migration of Barn Swallows Hirundo rustica from southern Africa appears to be constrained by the need to complete their moult before leaving their non-breeding grounds [27], [85].…”

Migratory New World Blackbirds (Icterids) Are More Neophobic than Closely Related Resident Icterids

“…Thirdly, strong neophobia delays exploitation of newly emerging resources. Thus, strong neophobic reactions in migrants may contribute to negative population developments [52] in our increasingly faster changing environment. One of the most neophobic species in our study was the rusty blackbird.…”

Flexibility in phenology and habitat use act as buffers to long‐term population declines in UK passerines

“…Resource use, both habitat and diet, together with average 1st clutch laying based, in most cases, on changes in photoperiod (Dawson 2008) though it has been suggested that climatic conditions on their journey to the breeding grounds may also impact species ' ability to adjust their phenology (Moussus et al 2010). Resource use, both habitat and diet, together with average 1st clutch laying based, in most cases, on changes in photoperiod (Dawson 2008) though it has been suggested that climatic conditions on their journey to the breeding grounds may also impact species ' ability to adjust their phenology (Moussus et al 2010).…”

“…moult, migration, breeding) take place at the most appropriate time of the year (Stenseth and Mysterud 2002, Bradshaw and Holzapfel 2006, Dawson 2008, Carey 2009). Strong selection pressure for matching off spring needs with peak food abundance and minimizing the cost of reproduction at the egg-laying stage can result in fl exibility and diff erential responses amongst a range of species traits (Visser 2008, Carey 2009, Moussus et al 2010. If changes in environmental conditions (due either to climate change or habitat transformation) alter the optimal timing for breeding, species ' adaptation potential will depend on their ability to alter their phenology.…”

“…Hence, exploring trade-off s between phenology or phenological fl exibility and other ecological characteristics may provide insight into mechanisms underlying the links between phenology and population trends. Moussus et al (2010) showed that the degree of fl exibility in phenology was associated not only with climatic and ecological niche breath but also with migration. However, the degree of fl exibility in these traits additionally may be constrained by other characteristics such as migration.…”