Michael S. Webster

Group-living social systems are common in nature, but the adaptive benefits of these social systems and how they relate to mating systems have not been well studied. White-winged Fairywrens have one of the most complex and enigmatic avian social systems. Group territories are occupied and defended by up to 20 adults in brown plumage and 1 adult male in ornamented plumage (vivid blue and white on mainland Australia; black and white on 2 islands off the west coast), with up to 5 pairs breeding on each group territory, often with assistance from helpers. The adaptive benefits of this social structure and how it relates to the species’ mating system have not been studied. Here we present a field study of 2 populations (1 island, 1 mainland) during 2 consecutive breeding seasons in which we documented the social structure of adults and quantified the genetic relationships between 205 adults, 34 juveniles, and 158 nestlings. First- and second-order kin relationships between adults were more commonly observed across group territories than within, and although more than 70% of nestlings were sired by extrapair males, most extrapair sires were from outside of the social group territory. When social mates were first- or second-order kin, extrapair males were almost always unrelated, and extrapair males tended to be in better condition than the pair males they cuckolded. Our results do not clearly support previously suggested hypotheses (kin selection or cuckoldry) for this species’ complex social structure. The functional benefits of this social system remain enigmatic.

Sexually-selected ornaments typically confer reproductive benefits, but ornamented and unornamented male phenotypes often co-occur in the same population. Reduced social costs are one potential compensatory benefit of unornamented male phenotypes, but few studies have tested this hypothesis in a natural context. Here we present a field-based experiment testing whether ornamented plumage carries social costs in the red-backed fairywren (Malurus melanocephalus), a small Australian songbird that exhibits delayed but flexible plumage maturation. Only one-quarter of one-year-old male red-backed fairywrens acquire ornamented plumage, but young ornamented males obtain greater reproductive success than males that retain brown, female-like plumage. We experimentally tested whether ornamented plumage is associated with social costs by implanting brown one-year-old males with testosterone to induce molt into ornamented plumage, then recorded the resulting social interactions. Testosterone-implanted males developed ornamentation and were chased and attacked more often by conspecific males than were control-implanted males without ornamentation, supporting the hypothesis that molt into ornamented plumage is socially costly. However, despite these apparent costs, some one-year-old males naturally acquired ornamented plumage after pairing with a female. Paired one-year-olds who naturally acquired ornamented plumage exhibited smaller home ranges than the unpaired, implanted males in their natal groups. Post-hoc simulations suggested that smaller home ranges could result in fewer interactions with neighbors, meaning smaller home ranges may reduce the social costs associated with acquiring ornamentation. We discuss the aspects of manipulating ornamentation with testosterone and suggest that our results add to growing evidence that social costs can enforce the honesty of sexually-selected ornaments.

Biodiversity collections in the United States hold over a billion specimens and are essential to understanding the history of life on Earth, as well as patterns of biodiversity in response to environmental change. Each specimen is linked by metadata to an organism's name and the place and time of its collection. Extensive data have been collected on Earth's geology, hydrology, climate, and organisms—past and present—but the data remain largely fragmented. We report in the present article on community discussions to develop a roadmap and identify action items for the Building an Integrated, Open, Findable, Accessible, Interoperable, and Reusable (BIOFAIR) Data Network, directly linking the various types of biological and environmental data. The roadmap is organized into five themes: stocktaking and gap analysis, technological capacity building, best practices, education and training, and community building. Together, these themes chart a path from initial resource inventories and skill building to infrastructure development, cross‑disciplinary collaboration, and the establishment of FAIR‑compliant workflows and governance.