Jeremy Summers, Dieter Lukas, Corina J. Logan, Nancy ChenPlease use the format "First name initials family name" as in "Marie S. Curie, Niels H. D. Bohr, Albert Einstein, John R. R. Tolkien, Donna T. Strickland"
<p>---This is a POST-STUDY manuscript for the PREREGISTRATION, which received in principle acceptance in 2020 from Dr. Sebastián González (reviewed by Caroline Nieberding, Tim Parker, and Pizza Ka Yee Chow; <a href="https://doi.org/10.24072/pci.ecology.100062">10.24072/pci.ecology.100062</a>). We are now submitting the first of the three resulting manuscripts for its post-study peer review. It would be ideal if the post-study review could be handled by the same recommender and reviewers for continuity (note that we are not in a rush and are happy to wait if it means we can have the same recommender and reviewers). For instructions on how to evaluate a post-study (Stage 2) manuscript that received pre-study in principle recommendation by PCI Ecology, please see the guidelines for <a href="https://rr.peercommunityin.org/help/guide_for_recommenders#h_6759646236401613643390905">recommenders</a> and <a href="https://rr.peercommunityin.org/help/guide_for_reviewers#h_6720026472751613309075757">reviewers</a> at PCI Registered Reports. Please note that the Introduction, Hypothesis, and Methods sections are not available for review at this stage because they were pre-approved.---</p>
<p><br>Species ranges are set by limitations in factors including climate tolerances, habitat use, and dispersal abilities. Understanding the factors governing species range dynamics remains a challenge that is ever more important in our rapidly changing world. Species ranges can shift if environmental changes affect available habitat, or if the niche or habitat connectivity of a species changes. We tested how changes in habitat availability, niche, or habitat connectivity could contribute to divergent range dynamics in a sister-species pair. The great-tailed grackle (Quiscalus mexicanus) has expanded its range northward from Texas to Nebraska in the past 40 years, while its closest relative, the boat-tailed grackle (Quiscalus major), has remained tied to the coasts of the Atlantic Ocean and the Gulf of Mexico as well as the interior of Florida. We created species distribution and connectivity models trained on citizen science data from 1970-1979 and 2010-2019 to determine how the availability of habitat, the types of habitat occupied, and range-wide connectivity have changed for both species. We found that the two species occupy distinct habitats and that the great-tailed grackle has shifted to occupy a larger breadth of urban, arid environments farther from natural water sources. Meanwhile, the boat-tailed grackle has remained limited to warm, wet, coastal environments. We found no evidence that changes in habitat connectivity affected the ranges of either species. Overall, our results suggest that the great-tailed grackle has shifted its realized niche as part of its rapid range expansion, while the range dynamics of the boat-tailed grackle may be shaped more by climate change. The expansion in habitats occupied by the great-tailed grackle is consistent with observations that species with high behavioral flexibility can rapidly expand their geographic range by using human-altered habitat. This investigation identifies how opposite responses to anthropogenic change could drive divergent range dynamics, elucidating the factors that have and will continue to shape species ranges.</p>
Geographic range expansion, habitat, niche, connectivity, range dynamics, anthropogenic environmental change, grackle
Behaviour & Ethology, Biogeography, Dispersal & Migration, Human impact, Landscape ecology, Preregistrations, Species distributions
