Spatial variation in avian bill size is associated with temperature extremes in a major radiation of Australian passerines.

Morphology is integral to body temperature regulation. Recent advances in understanding of thermal physiology suggest a role of the avian bill in thermoregulation. To explore the adaptive significance of bill size for thermoregulation we characterized relationships between bill size and climate extremes.

Shape-shifting: changing animal morphologies as a response to climatic warming.

Many animal appendages, such as avian beaks and mammalian ears, can be used to dissipate excess body heat. Allen's rule, wherein animals in warmer climates have larger appendages to facilitate more efficient heat exchange, reflects this. We find that there is widespread evidence of 'shape-shifting' (changes in appendage size) in endotherms in response to climate change and its associated climatic warming.

Too hot to handle? Behavioural plasticity during incubation in a small, Australian passerine.

Global warming and intensifying extreme heat events may affect avian reproductive success and costs, particularly in hot, arid environments. It is unclear how breeding birds alter their behaviour in response to rapid climate change, and whether such plasticity will be sufficient to offset rising temperatures. We examine whether a small, open-cup nesting, passerine - the Jacky Winter Microeca fascinans - in semi-arid Australia, exhibits similar levels of behavioural plasticity when incubating under high temperatures as low, and how heat impacts upon parental effort, body mass change and reproductive success.

Australian songbird body size tracks climate variation: 82 species over 50 years.

The observed variation in the body size responses of endotherms to climate change may be explained by two hypotheses: the size increases with climate variability () and the size shrinks as mean temperatures rise (). Across 82 Australian passerine species over 50 years, shrinking was associated with annual mean temperature rise exceeding 0.012°C driven by rising winter temperatures for arid and temperate zone species.

Effects of extreme weather on two sympatric Australian passerine bird species.

Despite abundant evidence that natural populations are responding to climate change, there are few demonstrations of how extreme climatic events (ECEs) affect fitness. Climate warming increases adverse effects of exposure to high temperatures, but also exposure to cold ECEs. Here, we investigate variation in survival associated with severity of summer and winter conditions, and whether survival is better predicted by ECEs than mean temperatures using data from two coexisting bird species monitored over 37 years in southwestern Australia, red-winged fairy-wrens, and white-browed scrubwrens, Changes in survival were associated with temperature extremes more strongly than average temperatures.

Are long-term widespread avian body size changes related to food availability? A test using contemporaneous changes in carotenoid-based color.

Recent changes in global climate have been linked with changes in animal body size. While declines in body size are commonly explained as an adaptive thermoregulatory response to climate warming, many species do not decline in size, and alternative explanations for size change exist. One possibility is that temporal changes in animal body size are driven by changes in environmental productivity and food availability.

Individual and demographic consequences of reduced body condition following repeated exposure to high temperatures.

Although the lethal consequences of extreme heat are increasingly reported in the literature, the fitness costs of exposure to sublethal high air temperatures, typically identified in the 30-40 degrees C range, are poorly understood. We examine the effect of high (> or = 35 degrees C) daily maxima on body condition of a semiarid population of White-plumed Honeyeaters, Ptilotula penicillatus, monitored between 1986 and 2012. During this 26-yr period, temperature has risen, on average, by 0.

Dynamic size responses to climate change: prevailing effects of rising temperature drive long-term body size increases in a semi-arid passerine.

Changes in animal body size have been widely reported as a correlate of contemporary climate change. Body size affects metabolism and fitness, so changing size has implications for resilience, yet the climatic factors that drive size variation remain poorly understood. We test the role of mean and extreme temperature, rainfall, and remotely sensed primary productivity (NDVI) as drivers of body size in a sedentary, semi-arid Australian passerine, Ptilotula (Lichenostomus)penicillatus, over 23 years.

Morphometric measurements of dragonfly wings: the accuracy of pinned, scanned and detached measurement methods.

Large-scale digitization of museum specimens, particularly of insect collections, is becoming commonplace. Imaging increases the accessibility of collections and decreases the need to handle individual, often fragile, specimens. Another potential advantage of digitization is to make it easier to conduct morphometric analyses, but the accuracy of such methods needs to be tested.

Declining body size: a third universal response to warming?

A recently documented correlate of anthropogenic climate change involves reductions in body size, the nature and scale of the pattern leading to suggestions of a third universal response to climate warming. Because body size affects thermoregulation and energetics, changing body size has implications for resilience in the face of climate change. A review of recent studies shows heterogeneity in the magnitude and direction of size responses, exposing a need for large-scale phylogenetically controlled comparative analyses of temporal size change.

Phylogeny and evolution of the Meliphagoidea, the largest radiation of Australasian songbirds.

The Meliphagoidea comprises the largest radiation of Australasian passerines. Here we present the first detailed molecular phylogenetic analysis of its families and genera, particularly the Acanthizidae, using sequences from nine gene regions including both mitochondrial and nuclear DNA. Our results support some suggested relationships but challenge other groupings, particularly in Meliphagidae and Acanthizidae.

Shifting latitudinal clines in avian body size correlate with global warming in Australian passerines.

Intraspecific latitudinal clines in the body size of terrestrial vertebrates, where members of the same species are larger at higher latitudes, are widely interpreted as evidence for natural selection and adaptation to local climate. These clines are predicted to shift in response to climate change. We used museum specimens to measure changes in the body size of eight passerine bird species from south-eastern Australia over approximately the last 100 years.

Recognition of other species' aerial alarm calls: speaking the same language or learning another?

Alarm calls given by other species potentially provide a network of information about danger, but little is known about the role of acoustic similarity compared with learning in recognition of heterospecific calls. In particular, the aerial 'hawk' alarm calls of passerines provide a textbook example of signal design because many species have converged on a design that thwarts eavesdropping by hawks, and call similarity might therefore allow recognition. We measured the response of fairy-wrens (Malurus cyaneus) to playback of acoustically similar scrubwren (Sericornis frontalis) aerial alarm calls.