Lund University, Department of Biology, Section for Evolutionary Ecology, Sölvegatan 37, SE-223 62 Lund, Sweden
Lund University, Department of Biology, Section for Evolutionary Ecology, Sölvegatan 37, SE-223 62 Lund, Sweden.
J Exp Biol. 2021 Jan 12;224(Pt 1):jeb237743. doi: 10.1242/jeb.237743.
Incubating birds trade off self-maintenance for keeping eggs warm. This causes lower incubation temperature in more challenging conditions, with consequences for a range of offspring traits. It is not yet clear how low developmental temperature affects cold tolerance early in life. This is ecologically important because before full thermoregulatory capacity is attained, precocial chicks must switch between foraging and being brooded when their body temperature declines. Hence, we studied how cold tolerance during conditions similar to a feeding bout in the wild was affected by incubation temperature in Japanese quail (). Cold-incubated (35.5°C) chicks took the longest to develop, hatched at a smaller size, and remained smaller during their first week of life compared with chicks incubated at higher temperatures (37.0 and 38.5°C). This was reflected in increased cooling rate and reduced homeothermy, probably on account of reductions in both heat-producing capacity and insulation. Lower cold tolerance could exacerbate other temperature-linked phenotypic effects and, hence, also the trade-off between future and current reproduction from the perspective of the incubating parent.
孵化中的鸟类会在自我维持和孵卵保暖之间做出权衡。这会导致在更具挑战性的条件下孵化温度更低，从而影响一系列后代特征。目前还不清楚低温发育对生命早期的耐寒性有何影响。这在生态学上很重要，因为在完全获得体温调节能力之前，早成性雏鸟的体温下降时，必须在觅食和被孵化之间切换。因此，我们研究了在类似于野外觅食期间的条件下，孵化温度如何影响日本鹌鹑（）的耐寒性。与在较高温度（37.0 和 38.5°C）下孵化的雏鸟相比，在 35.5°C 下孵化的雏鸟发育时间最长，孵化时体型较小，并且在生命的第一周内体型仍然较小。这反映在冷却速度增加和体温调节能力降低上，这可能是由于产热能力和隔热能力的降低所致。较低的耐寒性可能会加剧与温度相关的其他表型效应，因此也会加剧从孵化亲代的角度来看，未来和当前繁殖之间的权衡。
