Environmental conditions but not nest composition affect reproductive success in an urban bird

Abstract

Environmental conditions during development are critical for survival and can affect the expression of behavioral and life-history traits (Lindström, 1999;Metcalfe & Monaghan, 2001). Changes in external conditions are particularly relevant for oviparous species (e.g., reptiles and birds). In these species, embryos develop inside an egg and are potentially exposed to environmental shifts that can involve suboptimal conditions for development (Ackerman & Lott, 2004;Ar & Sidis, 2002). In order to reduce such environmental variation, egg-laying species, and birds in particular, have evolved a suite of incubation strategies and behavioral adaptations (Deeming, 2002a;Deeming & Ferguson, 1991).In birds, eggs are often incubated by breeding individuals in nests (Deeming, 2002a(Deeming, , 2016. The incubating bird forms a functional unit with its nest, providing appropriate conditions for the development of embryos (Deeming, 2016). The functional properties of the birdnest unit can be shaped by the behavior of the incubating individual

The delayed effect of climatic conditions on pre‐fledging nestling haematocrit in a suboscine species in Patagonia

“…This is likely to be the case in our field sites too where invertebrates are subject to the same weather limitations. Our findings on precipitation are also supported by Capilla‐Lasheras et al (2021) who found that high precipitation in the first 10 days of nestling development correlated with less nestlings successfully fledging. That study uses precipitation averages from the first 10 days of nestling development whilst our study is more specific, giving exact days when this is most important.…”

“…Unless climate breakdown comes to a halt, nestling haematocrit will likely become sub‐optimum in both locations and as a result nestling fitness will suffer. This may also impact post‐fledging survival rates and longevity in the future as has been observed in other passerines (Facey et al 2020, Brown et al 2021, Capilla‐Lasheras et al 2021).…”

“…For example, one study by Arct et al (2022) found that nestling weight and the environmental temperature just after hatching could predict their pre‐fledging weight. Another study by Capilla‐Lasheras et al (2021) found that high rainfall in the first ten days after hatching lowers the number of successful fledglings. Another study conducted in tropical rainforests on Cyphorhinus phaeocephalus (song wrens) found that as precipitation decreased across a geographical gradient, nestling haematocrit decreased (Busch et al 2011).…”

“…Interestingly, temperature and precipitation were not collinear in this study as tropical rainforests can maintain consistent temperatures but vary in precipitation. Precipitation was more influential on nestling haematocrit over ambient temperature, because in heavy precipitation, adults could not forage as much and therefore provided less food for nestlings which resulted in lower body weight and haematocrit (Capilla-Lasheras et al 2021, Arct et al 2022. The aforementioned studies show that the timing of climatic conditions are crucial in producing the best offspring and ensuring the best chances for post-fledging survival.…”

A Review of the Roles Materials Play in Determining Functional Properties of Bird Nests

“…Artificially heating Tree Swallow nests also had no effect on the number of feathers added to the nest during building or the reproductive outcome of the clutch (Holland & Shutler 2018). Capilla-Lasheras et al (2021) also concluded that the numbers of feathers in Tree Sparrow Passer montanus nests did not have an importance in protecting eggs or nestlings against fluctuations in environmental conditions.…”