The incubation environment does not explain significant variation in heart rate plasticity among avian embryos.

The conditions an organism experiences during development can modify how they plastically respond to short-term changes in their environment later in life. This can be adaptive because the optimal average trait value and the optimal plastic change in trait value in response to the environment may differ across different environments. For example, early developmental temperatures can adaptively modify how reptiles, fish and invertebrates metabolically respond to temperature.

Early-life telomeres are influenced by environments acting at multiple temporal and spatial scales.

An individual's telomere length early in life may reflect or contribute to key life-history processes sensitive to environmental variation. Yet, the relative importance of genetic and environmental factors in shaping early-life telomere length is not well understood as it requires samples collected from multiple generations with known developmental histories. We used a confirmed pedigree and conducted an animal model analysis of telomere lengths obtained from nestling house sparrows (Passer domesticus) sampled over a span of 22 years.

Variation in Embryonic Metabolic Reaction Norms and the Role of the Environment.

AbstractEarly developmental environments can shape how organisms respond to later environments, but despite the potential for this phenomenon to alter the evolution of phenotypes and their underlying mechanisms in variable environments, details of this process are not understood. For example, both temperature and parental age can alter offspring metabolic plasticity and growth within species, yet the extent of such effects is unknown. We measured the reaction norms of embryonic heart rate in response to egg temperature and the change in egg mass over the incubation period in wild house sparrows.

Quantitative Evaluation of Tactile Foraging Behavior in Pekin and Muscovy Ducks.

Ducks have developed a variety of foraging strategies that utilize touch sensitive bills to match their ecological niche within wetlands. These techniques include diving, sieving, dabbling, and grazing. Ducks exhibiting tactile specialization in foraging outperform visual and non-tactile foraging ducks in behavioral experiments and have a higher percentage of light-touch mechanoreceptor neurons expressing Piezo2 in the trigeminal ganglia.

Temperature-mediated plasticity in incubation schedules is unlikely to evolve to buffer embryos from climatic challenges in a seasonal songbird.

Phenotypic plasticity is hypothesized to facilitate adaptive responses to challenging conditions, such as those resulting from climate change. However, tests of the key predictions of this 'rescue hypothesis', that variation in plasticity exists and can evolve to buffer unfavourable conditions, remain rare. Here, we investigate among-female variation in temperature-mediated plasticity of incubation schedules and consequences for egg temperatures using the chestnut-crowned babbler (Pomatostomus ruficeps) from temperate regions of inland south-eastern Australia.

Advancing breeding phenology does not affect incubation schedules in chestnut-crowned babblers: Opposing effects of temperature and wind.

Projecting population responses to climate change requires an understanding of climatic impacts on key components of reproduction. Here, we investigate the associations among breeding phenology, climate and incubation schedules in the chestnut-crowned babbler (), a 50 g passerine with female-only, intermittent incubation that typically breeds from late winter (July) to early summer (November). During daylight hours, breeding females spent an average of 33 min on the nest incubating (hereafter on-bouts) followed by 24-min foraging (hereafter off-bouts), leading to an average daytime nest attentiveness of 60%.