Browsing by Subject "Reptiles"
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Item Reassessing middle and inner ear morphometrics in the estimation of auditory capabilities in reptiles(2021-05) Nelson, Jasmine R.; Clarke, Julia A.Hearing, which facilitates the localization of sound and perception of acoustic communication, is directly measurable in living reptiles, but must be indirectly inferred in extinct taxa from morphological proxies. Current proxies utilize only measurements of the inner ear and do not use phylogenetic statistical approaches. Here, we use phylogenetic least squares regressions incorporating morphometrics of the middle and inner ears of extant reptiles (e.g. endosseous cochlear duct length, oval window area) to predict hearing acuity (hearing range, best frequency, minimum, and maximum hearing frequency). We use measures of hearing acuity obtained from audiograms and X-ray Computed Tomography data from a sample of 56 reptiles to develop a reptile model, and a subset of this dataset to develop Aves-specific (n=25) and Lepidosauria-specific (n=27) models. The best-fitting models, assessed through the Akaike Information Criterion (AICc) with small sample correction, were used in estimating the hearing of a sample of extinct reptiles. We find clade-specific relationships among ear measures and hearing, with models including middle ear values performing best. We recover significantly lower hearing estimates than previously estimated. These proxies will allow for more accurate estimates of hearing and a better understanding of hearing shifts in deep timeItem A review of the impacts of invasive grasses on herpetofauna(2015-08) Wright, Ian Michael; Gilbert, Lawrence E.; Leibold, Mathew ASpecies invasions pose one of the greatest threats to the maintenance and stability of biodiversity in ecosystems across the globe (Vitousek 1990). Plant species in particular are uniquely predisposed to successfully invade and establish themselves in novel habitats. In the United States alone invasive plants are responsible for nearly 35 billion dollars in economic and environmental damage. Grasslands are among the most productive ecosystems in the US and their biodiversity is threatened by continual introduction of alien grass species. These invasive grasses have a variety of direct and indirect effects on native grassland communities and have the ability to alter fire regimes, displace native species, and simplify grassland food webs. Little is known about the impacts invasive grasses have to amphibians and reptiles but there is evidence to suggest that these and other small organisms suffer direct mortality, impoverished prey sources, and reduced reproductive opportunities as a consequence of grass invasions. Here I summarize the current literature surrounding invasive grass impacts on herpetofauna and suggest topics of further research.