Go west, young bunting: recent climate change drives rapid movement of a Great Plains hybrid zone.

Describing how hybrid zones respond to anthropogenic influence can illuminate how the environment regulates both species distributions and reproductive isolation between species. In this study, we analyzed specimens collected from the Passerina cyanea x P. amoena hybrid zone between 2004 and 2007 and between 2019 and 2021 to explore changes in genetic structure over time. This comparison follows a previous study that identified a significant westward shift of the Passerina hybrid zone during the latter half of the twentieth century. A second temporal comparison of hybrid zone genetic structure presents unique potential to describe finer-scale dynamics and to identify potential mechanisms of observed changes more accurately. After concluding that the westward movement of the Passerina hybrid zone has accelerated in recent decades, we investigated potential drivers of this trend by modeling the influence of bioclimatic and landcover variables on genetic structure. We also incorporated eBird data to determine how the distributions of P. cyanea and P. amoena have responded to recent climate and landcover changes. We found that the distribution of P. cyanea in the northern Great Plains has shifted west to track a moving climatic niche, supporting anthropogenic climate change as a key mediator of introgression in this system.

Estimating hybridization in the wild using citizen science data: A path forward.

Genomic evidence of introgression in natural populations has reinvigorated the study of hybridization in recent years. Still, it is largely unknown how frequently individual organisms mate across species lines. Recently, Justyn et al. suggested that eBird, one of the world's largest citizen science databases, may supply adequate data for estimating hybridization rates. Here, we compare Justyn et al.'s estimates-and their conclusions that hybridization is rare-with estimates from museum and molecular data. We also estimate hybridization using eBird observations from areas and times when hybridization is possible, namely, in contact zones during the breeding season. These estimates are all considerably higher than those reported in Justyn et al., emphasizing that inferences from multiple datasets can differ radically. Finally, we demonstrate an approach for predicting the location of hybrid zones using eBird data, which can be done with high confidence and with unprecedented resolution. We show that citizen science data, far from settling the question of how frequently bird species hybridize, instead offer a promising step toward more focused study of hybrid zones.

Infections Associated with Temporary External Fixation.

Infections associated with external fixation are thought to be related to the fixator construct, the length of time a fixator is on the limb and the injury severity score (ISS). Patients who had temporary external fixation applied for lower extremity fractures were included. Charts were reviewed for prevalence of infection, loss of reduction or other external fixator modification. Other variables were length of time the fixator was applied and the length of hospitalization. Seventy-five patients with 80 fractures met our study criteria. Of 80 fractures, 23 (28.8%) were associated with infection at the fracture site. Average time to conversion from external fixation to definitive fixation was 13.23 ± 19.8 for infected fractures and 20.03 ± 17.08 (p = 0.137) for those without infection. We did not find that the length of time a fixator was applied was associated with an increased infection rate of the fracture site, the pin sites or other regions. (Journal of Surgical Orthopaedic Advances 29(2):73-76, 2020).