Barn swallows long-distance migration occurs between significantly temperature-correlated areas

Abstract

Organisms are routinely confronted with crucial decisions on the best time and place to perform fundamental activities. However, unpredictable spatio-temporal variation in ecological factors makes life-history optimization difficult particularly for long-distance migrants, which are putatively blind of conditions thousands of kilometers and weeks ahead along their journey. Here we challenge, on a hierarchy of geographical scales, the common wisdom that migratory birds have no clue to ecological conditions at destination. Using ringing data of the inter-continental migrating barn swallow (Hirundo rustica), we show that temperatures at breeding sites and at times of arrival from migration are more correlated with those at actual wintering sites and at times of departure than with those at other sites and at periods before/after departure. Hence, individual swallows have clues to adjust timing of spring migration based on expected conditions at destination, and they apparently choose wintering sites to increase availability of such information.

The start of migration correlates with arrival timing, and the total speed of migration increases with migration distance in migratory songbirds: a cross-continental analysis

“…This study illustrates the high potential for the start of migration to affect variation in arrival timing if the within-species effects quantified here correctly characterize within-individual effects. Since the anthropogenic changes in the climate and environment at wintering grounds are unlikely to coincide with the changes in breeding areas [133], but see also Pancerasa et al [134], it is not a phenotypic response alone but also an evolutionary shift in the start of spring migration that most likely explains the advanced breeding area arrival timing [6, 13]. Additionally, environmental conditions phenotypically affect the total speed of migration through an influence of varying feeding conditions at stopover sites on the total stopover duration [30, 77] and an influence of varying wind conditions on ground speed [31].…”

Demography of Common Swifts (Apus apus) breeding in the UK associated with local weather but not aphid biomass

“…The Swift differs from these hirundines in both foraging strategy (reaching higher altitudes) and nesting strategy (tending to nest in more urban areas), but all show distinct migratory strategies (e.g. Pancerasa et al 2018Pancerasa et al , Åkesson et al 2020.…”

Temporospatial Shifts in Sandhill Crane Staging in the Central Platte River Valley in Response to Climatic variation and Habitat Change

“…For analyses, we included mean daily average temperatures and the mean Palmer Drought Severity Index (PDSI) values at all wintering sites for the months of January and February. Mean daily average temperatures across seasonal periods have been used to assess the effect of climatic variation and climate change on bird migration distances (Visser et al 2009), timing of arrival on breeding grounds (McKinney et al 2012), and a host of other phenological and chronological questions (Thackeray et al 2016, Pancerasa et al 2018. Seasonal PDSI values have been linked to the timing of nest initiation (Brown and Brown 2014) as well as habitat use (Igl and Johnson 1999).…”