Programmed DNA elimination drives rapid genomic innovation in two thirds of all bird species.

Bird genomes are among the most stable in terms of synteny and gene content across vertebrates. However, germline-restricted chromosomes (GRCs) represent a striking exception where programmed DNA elimination confines large-scale genomic changes to the germline. GRCs are known to occur in songbirds (oscines), but have been studied only in a few species of Passerides such as the zebra finch, the key model for passerine genomics.

Linking performance to powerhouse: mitochondrial aerobic metabolism in blood cells reflects flight endurance of house sparrows ().

Identifying the physiological mechanisms underpinning inter-individual differences in performance and fitness remains a key challenge in organismal biology. Variation in mitochondrial aerobic metabolism has been suggested to underlie inter-individual variation in performance, but this remains seldom tested, partly because of the need to use terminal sampling for assessing mitochondrial parameters. To fill this knowledge gap, we investigated whether inter-individual variation in mitochondrial aerobic parameters measured from less-invasively taken samples (i.

Spatial extent and age-related bioaccumulation of fluoride in the bones of house sparrows around aluminium smelting operations.

Industrial fluoride emissions negatively impact animal health and remain elevated over large areas surrounding point sources. Here, we examined the geographic and demographic determinants of fluoride exposure in 42 house sparrows (Passer domesticus) from 14 sites around two aluminium smelting operations in Australia. We found that mean bone fluoride concentrations increased with age and were significantly higher in adult (1062 mg/kg) than in juvenile (603 mg/kg) house sparrows.

Independent evolution of atypical sperm morphology in a passerine bird.

Spermatozoa exhibit striking morphological variation across the animal kingdom. In passerine birds, sperm exhibit considerable variation in size, yet the basic sperm phenotype is highly conserved; sperm are filiform, the head is corkscrew-shaped, and the midpiece is elongated and twisted around the flagellum. A significant departure from this typical sperm morphology has been reported in the sister species, the Eurasian bullfinch (Pyrrhula pyrrhula) and Azores bullfinch (P.

Telomere length declines with mean blood lead concentration in an urban passerine.

Lead (Pb) is a highly toxic and widespread environmental pollutant and can severely harm body tissues as well as DNA. Pb could potentially damage telomeres, whose length and shortening rate are linked with cellular senescence, physiological state, and mortality. Yet, studies investigating Pb and telomere dynamics in natural systems remain inconclusive.

Relationships between ambient temperature and diurnal variation in physiological responses to acute handling and restraint stress in the house sparrow, Passer domesticus.

Climate change is altering the frequency and intensity of environmental extremes, and the diurnal rates of environmental change. The daily reaction norms of wild animals show spatial and temporal plasticity to allow appropriate physiological responses to predictable environmental challenges, but these responses have rarely been quantified in wild birds. We addressed this by determining whether physiological stress indices (corticosterone [CORT], glucose [GLU], and circulating heat shock proteins [Hsp]) vary with ambient temperature (T) or time of day across a 6 latitudinal gradient (32-38 S).

Experimental demonstration of functional divergence in mitochondrial metabolism between two finch subspecies subjected to a thermal challenge.

Whilst there is a growing appreciation that mitochondrial divergence across lineages is not selectively neutral, less work has examined the functional differences that may exist in closely divergent taxa. We measured mitochondrial oxygen consumption in the blood of two subspecies of an Australian songbird-the long-tailed finch, Poephila acuticauda-before and after ten days of heat treatment at 40°C to explore mitochondrial metabolic plasticity in response to thermal stress. There were significant differences between subspecies in the efficiency of oxidative phosphorylation, with P.

Germline mutation rates and fine-scale recombination parameters in zebra finch.

Most of our understanding of the fundamental processes of mutation and recombination stems from a handful of disparate model organisms and pedigree studies of mammals, with little known about other vertebrates. To gain a broader comparative perspective, we focused on the zebra finch (Taeniopygia castanotis), which, like other birds, differs from mammals in its karyotype (which includes many micro-chromosomes), in the mechanism by which recombination is directed to the genome, and in aspects of ontogenesis. We collected genome sequences from three generation pedigrees that provide information about 80 meioses, inferring 202 single-point de novo mutations, 1,088 crossovers, and 275 non-crossovers.

Animal social networks are robust to changing association definitions.

Unlabelled: The interconnecting links between individuals in an animal social network are often defined by discrete, directed behaviours, but where these are difficult to observe, a network link (edge) may instead be defined by individuals sharing a space at the same time, which can then be used to infer a social association. The method by which these associations are defined should be informed by the biological significance of edges, and therefore often vary between studies. Identifying an appropriate measure of association remains a challenge to behavioural ecologists.

Same data, different analysts: variation in effect sizes due to analytical decisions in ecology and evolutionary biology.

Although variation in effect sizes and predicted values among studies of similar phenomena is inevitable, such variation far exceeds what might be produced by sampling error alone. One possible explanation for variation among results is differences among researchers in the decisions they make regarding statistical analyses. A growing array of studies has explored this analytical variability in different fields and has found substantial variability among results despite analysts having the same data and research question.

Constant companions: wild zebra finch pairs display extreme spatial cohesion.

Many animals maintain long-term monogamous partnerships, but the extent to which partners associate varies substantially and has implications for the scope of cooperation between pair members. Zebra finches () are monogamously paired for life and maintain continuous partnerships, raising questions as to if and how they maintain pair cohesion despite being non-territorial and having only short-range acoustic signals. While zebra finches are the best-studied songbird in captivity, their social and spatial behaviour in the wild is poorly understood.

Spread of yellow-bill-color alleles favored by selection in the long-tailed finch hybrid system.

Carotenoid pigments produce the yellow and red colors of birds and other vertebrates. Despite their importance in social signaling and sexual selection, our understanding of how carotenoid ornamentation evolves in nature remains limited. Here, we examine the long-tailed finch Poephila acuticauda, an Australian songbird with a yellow-billed western subspecies acuticauda and a red-billed eastern subspecies hecki, which hybridize where their ranges overlap.

Mutation and recombination parameters in zebra finch are similar to those in mammals.

Most of our understanding of the fundamental processes of mutation and recombination stems from a handful of disparate model organisms and pedigree studies of mammals, with little known about other vertebrates. To gain a broader comparative perspective, we focused on the zebra finch (), which, like other birds, differs from mammals in its karyotype (which includes many micro-chromosomes), in the mechanism by which recombination is directed to the genome, and in aspects of ontogenesis. We collected genome sequences from three generation pedigrees that provide information about 80 meioses, inferring 202 single-point mutations, 1,174 crossovers, and 275 non-crossovers.

Correction to: 'Unscrambling variation in avian eggshell colour and patterning in a continent-wide study' (2019), by L'Herpiniere .

[This corrects the article DOI: 10.1098/rsos.181269.

House Sparrows as Sentinels of Childhood Lead Exposure.

Our understanding of connections between human and animal health has advanced substantially since the canary was introduced as a sentinel of toxic conditions in coal mines. Nonetheless, the development of wildlife sentinels for monitoring human exposure to toxins has been limited. Here, we capitalized on a three-decade long child blood lead monitoring program to demonstrate that the globally ubiquitous and human commensal house sparrow () can be used as a sentinel of human health risks in urban environments impacted by lead mining.

Blood lead increases and haemoglobin decreases in urban birds along a soil contamination gradient in a mining city.

Lead contaminated soil is a persistent global threat to the health of animal populations. Nevertheless, links between soil lead and its adverse effects on exposed wildlife remain poorly understood. Here, we explore local geographic patterns of exposure in urban birds along a gradient of lead contamination in Broken Hill, an Australian mining city.

The ecology of zebra finch song and its implications for vocal communication in multi-level societies.

Acoustic signalling is crucial in affecting movements and in social interactions. In species with dynamic social structures, such as multi-level societies, acoustic signals can provide a key mechanism allowing individuals to identify and find or avoid each other and to exchange information. Yet, if the spacing between individuals regularly exceeds the maximum signalling range, the relation between movements and signals becomes more complex.

Mitonuclear interactions impact aerobic metabolism in hybrids and may explain mitonuclear discordance in young, naturally hybridizing bird lineages.

Understanding genetic incompatibilities and genetic introgression between incipient species are major goals in evolutionary biology. Mitochondrial genes evolve rapidly and exist in dense gene networks with coevolved nuclear genes, suggesting that mitochondrial respiration may be particularly susceptible to disruption in hybrid organisms. Mitonuclear interactions have been demonstrated to contribute to hybrid dysfunction between deeply divergent taxa crossed in the laboratory, but there are few empirical examples of mitonuclear interactions between younger lineages that naturally hybridize.

High nest failure in a zebra finch population and persistent nest predation by a monitor lizard.

Predation is well known to have substantial effects on behaviour and fitness in many animals. In songbirds, nest predation is rarely observed directly, so that research focusses primarily on the consequences of predation and less on the behaviour of the predator. Here, we report predation data in a zebra finch () nest box population, highlighting a 22-min-long sequence, captured on video, of a sand goanna () predating a zebra finch nest in the wild.

Exposure to Sublethal Concentrations of Lead (Pb) Affects Ecologically Relevant Behaviors in House Sparrows (Passer domesticus).

Global contamination of environments with lead (Pb) poses threats to many ecosystems and populations. While exposure to Pb is toxic at high concentrations, recent literature has shown that lower concentrations can also cause sublethal, deleterious effects. However, there remains relatively little causal investigation of how exposure to lower concentrations of environmental Pb affects ecologically important behaviors.

Heat stress conditions affect the social network structure of free-ranging sheep.

Extreme weather conditions, like heatwave events, are becoming more frequent with climate change. Animals often modify their behaviour to cope with environmental changes and extremes. During heat stress conditions, individuals change their spatial behaviour and increase the use of shaded areas to assist with thermoregulation.

Correction to: 'Fission-fusion dynamics in sheep: the influence of resource distribution and temporal activity patterns' (2023) by Della Libera .

[This corrects the article DOI: 10.1098/10.1098/rsos.

Fission-fusion dynamics in sheep: the influence of resource distribution and temporal activity patterns.

Fission-fusion events, i.e. changes to the size and composition of animal social groups, are a mechanism to adjust the social environment in response to short-term changes in the cost-benefit ratio of group living.

Effects of heat waves on telomere dynamics and parental brooding effort in nestlings of the zebra finch (Taeniopygia castanotis) transitioning from ectothermy to endothermy.

Heat waves are predicted to be detrimental for organismal physiology with costs for survival that could be reflected in markers of biological state such as telomeres. Changes in early life telomere dynamics driven by thermal stress are of particular interest during the early post-natal stages of altricial birds because nestlings quickly shift from being ectothermic to endothermic after hatching. Telomeres of ectothermic and endothermic organisms respond differently to environmental temperature, but few investigations within species that transition from ectothermy to endothermy are available.

Longitudinal covariation of testosterone and sperm quality across reproductive stages in the zebra finch.

Birds that breed opportunistically maintain partial activation of reproductive systems to rapidly exploit environmental conditions when they become suitable for breeding. Maintaining reproductive systems outside of a breeding context is costly. For males, these costs are thought to include continual exposure to testosterone.