A window on the past: male ornamental plumage reveals the quality of their early-life environment

It is well established that the expression of many ornamental traits is dependent on the current condition of the bearer. However, conditions experienced in early life are also known to be important for an individual's subsequent fitness and therefore, directly or indirectly, for the fitness of their mate. Specifically, a recent hypothesis suggests that sexually selected traits might be sensitive to conditions experienced during early-life development and thereby function as honest indicators of developmental history. Whether this applies to colourful male plumage, however, is largely unknown. We tested this idea with a field experiment by manipulating neonatal nutrition in a sexually dichromatic passerine, the hihi (Notymystis cincta). We found that carotenoid supplementation increased nestling plasma carotenoid concentration, which was in turn correlated with increased yellow saturation in male breeding plumage after moulting. We also found that the post-moult luminance (lightness) of the white ear-tufts tended to be reduced in males that had received an all-round nutritional supplement as nestlings. Black breeding plumage was not affected by neonatal nutritional treatment. Although the mechanisms that generate colourful plumage are evidently diverse, our results show that at least some parts of this display are accurate indicators of environmental conditions during development

Birdstrikes and barcoding: can DNA methods help make the airways safer?

While flying remains one of the safest means of travel, reported birdstrikes on aircraft have risen. This is a result of increased aircraft flight movements, changes in agricultural methods and greater environmental awareness contributing to growing populations of hazardous bird species, as well as more diligent reporting of incidents. Measures to mitigate this hazard require accurate data about the species involved; however, the remains of birds from these incidents are often not easy to identify. Reported birdstrikes include a substantial number where the species cannot be determined from morphology alone. DNA barcoding offers a reliable method of identifying species from very small amounts of organic material such as blood, muscle and feathers. We compare species identification based on morphological criteria and identifications based on mitochondrial cytochrome c oxidase subunit I DNA barcoding methods for New Zealand species. Our data suggest that DNA-based identification can substantially add to the accuracy of species identifications, and these methods represent an important addition to existing procedures to improve air safety. In addition, we outline simple and effective protocols for the recovery and processing of samples for DNA barcodingNo Full Tex

Extreme reversed sexual size dimorphism in the extinct New Zealand moa Dinornis

The ratite moa (Aves; Dinornithiformes) were massive graviportal browsers weighing up to 250kg (ref. 1) that dominated the New Zealand biota until their extinction approximately 500yr ago. Despite an extensive Quaternary fossil record, moa taxonomy remains problematic 1-4 and currently 11 species are recognized. Three Dinornis species were found throughout New Zealand and differed markedly in size (1-2 m height at back) and mass (from ∼34 to 242kg)1. Surprisingly, ancient mitochondrial DNA sequences show that the three species were genetically indistinguishable within each island, but formed separate North and South Island clades. Here we show, using the first sex-linked nuclear sequences from an extinct species, that on each island the three morphological forms actually represent just one species, whose size varied markedly according to sex and habitat. The largest females in this example of extreme reversed sexual size dimorphism were about 280% the weight and 150% the height of the largest males, which is unprecedented among birds and terrestrial mammals. The combination of molecular and palaeontological data highlights the difficulties of analysing extinct groups, even those with detailed fossil records