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ABSTRACT Nest sharing by birds, or the phenomenon where multiple individuals of different species contribute genetically and parentally to offspring in a single nest, is a rare form of cooperative breeding that has only occasionally been reported in socially monogamous birds. Here we describe, both behaviorally and genetically, the unique case of two female birds, a western kingbird (Tyrannus verticalis) and a western kingbird × scissor‐tailed flycatcher (T. forficatus) hybrid, simultaneously occupying (and likely co‐incubating eggs in) a single nest. Both females provisioned nestlings, and they did this in two consecutive years (producing four fledglings each year). Genomic data from the females revealed that they were unrelated, and parentage analyses revealed that both females contributed genetically to at least one of the offspring, and at least two fathers were involved. These observations represent the first reported case of nest sharing involving a hybrid individual and the first case within the family Tyrannidae. 

Why parasites occur in certain hosts in certain locations has been a long-standing question among ecological and evolutionary parasitologists. Encounter and compatibility filters summarize the likelihood that a host and parasite will physically interact and establish an infection upon contact. Encounter and compatibility filters are not fixed and, among multiple locations, the abiotic environmental characteristics and biotic community composition that contribute to the filters often vary spatially and temporally. Abiotic variation may directly affect hosts or parasites —particularly parasites with one or more free-living stages— whereas the local biotic community may dilute or amplify parasite transmission. Unlike directly transmitted parasites, complex-life cycle parasites use multiple hosts, thus having life cycles that, we hypothesize, are highly susceptible to the effects of spatiotemporal environmental variation. We modeled infection probability relationships of endohelminths from post-metamorphic wood frogs (Rana [Lithobates] sylvatica) and northern leopard frogs (Rana pipiens) with wetland characteristics, landscape composition, and the anuran species within the local community. Parasites included complex-life cycle trematodes that use amphibians as definitive hosts (Haematoloechus spp., Glypthelmins quieta) or as intermediate hosts (Alaria sp., Neodiplostomum sp., echinostomatids, Lechriorchis) and nematodes with direct or indirect life cycles (Cosmocercoides, Oswaldocruzia). Although our results demonstrate that distributions of parasites with complex and direct life cycles are correlated with some abiotic and biotic characteristics of the environment, there were few general trends. Each parasite's distribution had its own unique relationship with wetland, landscape, and amphibian-community variables and there was overall low predictability for most species. One landscape feature — the number of wetlands within the vicinity of the site of amphibian capture — was commonly included in top models for leopard frogs and could be associated with how definitive hosts (e.g., amphibians, mammals, birds) and intermediate hosts (e.g., snails, odonates) use the landscape. The amphibian community at any given site also commonly affected infection probabilities, such that the local presence of other species tended to reduce infection probabilities in sampled frogs, lending support to the dilution effect at the landscape level. Our research highlights the need to consider spatiotemporal sampling, environmental variation, and host-community variation when studying parasite prevalence in any given component community. 

Ex situ conservation, translocation, and reintroduction are becoming increasingly important for species restoration. In amphibians, however, effects of captive stress on adults and subsequent effects on their offspring that are later reintroduced into the wild are largely unknown. Using Fowler’s toads (Anaxyrus fowleri) as a model species, we investigated effects of increased captive stress on corticosterone (CORT) concentration in adult toads. We then examined CORT levels in their tadpole offspring, which we reared in natural ponds to simulate conditions of a reintroduced population. We found no significant effects of captive stress on adult or offspring CORT levels. However, despite poor model performance due to low sample size, baseline CORT of sires (but not dams) was the best predictor of, and negatively correlated with, baseline CORT and change in CORT in offspring. Our study provides a unique perspective on the potential translation of stress from parent to offspring and points to a need for a closer examination of paternal effects in cases of cross-generational studies in amphibians. 

We present the complete genome sequences of 11 species of kingbirds. Illumina sequencing was performed on genetic material from wild-caught and museum specimens. The reads were assembled using ade novomethod followed by a finishing step. The raw and assembled data are publicly available via Genbank. 

The non-breeding season is an understudied, yet likely critical, period for many species. Understanding species’ resource requirements, and determining when limited resources and increased densities may lead to intraspecific competition and demographic partitioning, may aid species conservation efforts. Monitoring species’ resource requirements during the non-breeding season may be more important in highly modified ecosystems, such as intensive agricultural landscapes, where anthropogenic pressures may further limit resources. The Loggerhead Shrike (Lanius ludovicianus) is a rapidly declining avian species that winters in agricultural areas in the southeastern United States, but little is known about their ecology or potential demographic partitioning in this context. To fill these knowledge gaps, we compared multi-scale habitat selection, survival, and space use across age and sex classes of shrikes inhabiting an agricultural landscape in Arkansas, USA. We found that habitat selection differed among demographic classes. Specifically, females preferred areas with more fallow cover, utility wires, and anthropogenic perches, whereas males preferred areas with more agricultural fields and ditches and less soybean cover. However, overall, shrikes exhibited numerous similarities in habitat selection, generally preferring areas with greater developed land cover (within a predominantly agricultural landscape), greater water availability, and taller perches. Despite the observed variability in habitat selection, no differences in apparent seasonal and annual survival rates or home range size existed among groups. However, non-breeding dispersal distance between years differed by age class, with older individuals being more site faithful than younger individuals. We suggest that the demographic habitat partitioning we detected may reflect adaptive differential life history strategies associated with age and sex classes, but further study of habitat selection by Loggerhead Shrikes across seasons and habitat types will help clarify the variation, importance, and potential carry-over effects of non-breeding habitat partitioning.