Patterns of life‐history traits in open‐nesting palearctic passerines as a function of the climatic variation of their ranges

Abstract

Latitude, a surrogate of climatic conditions, is commonly used in the examination of life‐history variation. However, the climatic mechanisms underlying latitudinal life‐history variation have only rarely been tested. Here, we test whether the number of climates to which species are subjected in their ranges predicts geographical life‐history variation. In particular, we examine whether eurytopic species, the range of which covers more climates, show different reproductive effort to stenotopic species, which are distributed over climatically more homogeneous environments. We examined female body mass, egg mass controlled for female body mass, clutch size and the number of breeding attempts per season for 34 sedentary and short‐distance migratory passerine species of the Western Palearctic. For each species, we assessed how many climate zones extend over the species’ wintering and breeding ranges. We found that avian body mass, and also clutch size, significantly increases with the number of climatic zones extended over the species’ wintering range. In turn, species whose breeding ranges span more climates show more breeding attempts per season. Whereas the mass of a single egg declines, clutch size increases with increasing climatic variation in breeding ranges. Our study suggests that the level of climatic variation over species’ ranges during and outside the breeding season might be responsible for variation in life‐history traits in open‐nesting Western Palearctic passerines.

Climate change and annual survival in a temperate passerine: partitioning seasonal effects and predicting future patterns

“…Effects of variation in reproductive investment on subsequent survival have been widely reported in other short‐lived species (Askenmo 1979, Nur 1984, Reid 1987), as well as in some long‐lived species (Deschamps et al 2009). However, few studies have shown an effect of variation in climate on this productivity versus survival tradeoff (Thomas et al 2001, Václav and Sánchez 2008, Moreno and Møller 2011), and the underlying mechanisms remain poorly understood (Harshman and Zera 2007, Deschamps et al 2009).…”

“…Such shifts are driven largely by local changes in population size as a result of altered productivity and survival (Huntley et al 2007, Leech andCrick 2007). The mechanisms underpinning such demographic changes are not well understood (Seavy et al 2008, Balbontín et al 2009, van de Pol et al 2010, despite increasing evidence that incorporating demographic mechanisms into predictive models of future climate change impacts greatly improves their performance (Buckley et al 2010, Bykova et al 2012. In order to improve predictive capacity it is essential to advance understanding of how variation in climate drives demographic processes, by using historical data to uncover detailed relationships between climate and demography.…”

Population changes in Czech passerines are predicted by their life‐history and ecological traits

“…Fox 2004), we expected that these population data would be of sufficient quality for further analyses. Our focus on passerine species only was motivated by an attempt to focus better on an analysis of life histories with a relatively homogeneous dataset without outlying values (see Václav & Sanchez 2008). Passerine species are a monophyletic and highly diversified group and they thus compose a suitable dataset to test our proposed hypotheses.…”

Ecological and environmental factors related to variation in egg size of New World flycatchers

“…Despite marked differences among several avian life‐ history traits within Nearctic and Neotropical regions (Ricklefs , Martin , ), detailed descriptions of geographical variation are mostly restricted to clutch size (Jetz et al ) in the Northern Hemisphere (Ricklefs , Václav and Sánchez ). Clutch size varies considerably from tropical to boreal regions (Lack , Jetz et al ), but it varies little across the Austral and Neotropical America (ANA) among most bird species (Skutch , Ricklefs ).…”