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Biology subjects

MacPherson, M.

Publications and source records attributed to MacPherson, M..

3 recordsLinked to original sources

Predicting Bird Distributions Under Global Change

An introduction to predictive distribution modelling for conservation to encourage novel perspectives. The rapid pace and potentially irreversible consequences of global change create an urgent need to predict the spatial responses of biota for conservation to better inform the prioritization and management of terrestrial habitats and prevent future extinctions. Here, we provide an accessible entry point to the field to guide near-future work building predictive species distribution models (SDMs) by synthesizing a technical framework for the proactive conservation of avian biodiversity. Our framework offers a useful approach to navigate the challenges surrounding the large spatio-temporal resolution of datasets and datasets that favor hypothesis testing at broad spatio-temporal scales and coarse resolutions, which can affect our ability to assess the validity of current predicted distributions. We explain how to improve the accuracy of predictive models by determining the extent to which: 1) dispersal limitation impacts the rate of range shifts, 2) taxa are rare at their range limits, and 3) land use and climate change interact. Finally, we offer approaches to filling knowledge gaps by creatively leveraging existing methods and data sources. RESUMENUna introduccion a la modelizacion predictiva de la distribucion para la conservacion con el fin de fomentar nuevas perspectivas. El rapido ritmo y las consecuencias potencialmente irreversibles del cambio global crean una necesidad urgente de predecir las respuestas espaciales de la biota para la conservacion, con el fin de informar mejor la priorizacion y gestion de los habitats terrestres y prevenir futuras extinciones. Aqui proporcionamos un punto de entrada accesible al campo para guiar el trabajo del futuro proximo en la construccion de modelos predictivos de distribucion de especies (SDM), sintetizando un marco tecnico para la conservacion proactiva de la biodiversidad aviar. Nuestro marco ofrece un enfoque util para navegar por los retos que rodean a la gran resolucion espacio-temporal de los conjuntos de datos y a los conjuntos de datos que favorecen la comprobacion de hipotesis a escalas espacio-temporales amplias y resoluciones gruesas, lo que puede afectar a nuestra capacidad para evaluar la validez de las distribuciones predichas actuales. Explicamos como mejorar la precision de los modelos predictivos determinando hasta que punto 1) la limitacion de la dispersion influye en el ritmo de los cambios de area de distribucion, 2) los taxones son raros en los limites de su area de distribucion, y 3) el uso del suelo y el cambio climatico interactuan. Por ultimo, proponemos enfoques para colmar las lagunas de conocimiento aprovechando de forma creativa los metodos y fuentes de datos existentes.

ecology

Morphology of migration: Associations between wing shape, bill morphology, and migration in kingbirds (Tyrannus)

Morphology is closely linked to locomotion and diet in animals. In animals that undertake long-distance migrations, limb-morphology is under selection to maximize mobility and minimize energy expenditure. Migratory behaviors also interact with diet, such that migratory animals tend to be dietary generalists, while sedentary taxa tend to be dietary specialists. Despite a hypothesized link between migration status and morphology, phylogenetic comparative studies have yielded conflicting findings. We tested for evolutionary associations between migratory status and limb and bill morphology across kingbirds, a pan-American genus of birds with migratory, partially migratory, and sedentary taxa. Migratory kingbirds had longer wings, in agreement with expectations if selection favors improved aerodynamics for long-distance migration. We also found an association between migratory status and bill shape, such that more migratory taxa had wider, deeper, and shorter bills compared to sedentary taxa. However, there was no difference in intraspecific morphological variation among migrants, partial migrants, and residents, suggesting that dietary specialization has evolved independently of migration strategy. The evolutionary links between migration, diet, and morphology in kingbirds uncovered here further strengthen ecomorphological associations that underlie long-distance seasonal movements in animals.

evolutionary biology

Using Touchscreen Equipped Operant Chambers to Study Comparative Cognition. Benefits, Limitations, and Advice.

Operant chambers are small enclosures used to test animal behavior and cognition. While traditionally reliant on simple technologies for presenting stimuli (e.g., lights and sounds) and recording responses made to basic manipulanda (e.g., levers and buttons), an increasing number of researchers are beginning to use Touchscreen-equipped Operant Chambers (TOCs). These TOCs have obvious advantages, namely by allowing researchers to present a near infinite number of stimuli as well as increased flexibility in the types of responses that can be made and recorded. Here, we trained wild-caught adult and juvenile great-tailed grackles (Quiscalus mexicanus) to complete experiments using a TOC. We have learned much from these efforts, and outline the advantages and disadvantages of these two approaches. We report data from our training sessions and discuss important modifications we made to facilitate animal engagement and participation in various tasks. Finally, we provide a "training guide" for creating experiments using PsychoPy, a free and open-source software that we have found to be incredibly useful during these endeavors. This article, therefore, should serve as a useful resource to those interested in switching to or maintaining a TOC, or who similarly wish to use a TOC to test the cognitive abilities of non-model species or wild-caught individuals.

animal behavior and cognition