Date of Award

2023

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Biology

First Advisor

Dr. James Watling

Abstract

Aim: The aims of this study were to compare the locations of climate refugia and diversity patterns of the Neotropical tribe Pseudoboini and to provide critical analysis of the potential role of climatic stability and ecological specialization in the contemporary and historical distribution of this group of snakes. We expected species with narrow ecological requirements to occupy climatically stable areas, whereas generalists and arboreal species would occupy areas with more variable climate.

Location: South America

Methods: We compiled observations from the scientific literature and herpetological notes (1844-2019) with additional data from museum collections throughout South America to create a database of geographical occurrences and ecological observations of pseudoboines. We used paleo and contemporary climate models from WorldClim to assess climatically stable areas and create niche models for species potential distributions during four time periods. We then tested the congruence between climate stable areas with contemporary regional hotspots of Pseudoboini and examined whether variation in the geographic pattern of whole distributions or range cores (areas predicted to be suitable through all time periods) was related to ecological specialization.

Results: Out of 49 Pseudoboini taxa, only 33 species had diet and microhabitat data, and 43 species had sufficient occurrences for paleo distributions to be modeled. We found that areas of 6 climate stability held significantly higher richness of Pseudoboini compared to unstable areas and that this pattern was consistent through time except during the Last Glacial Maximum. However, not all species relied on stable climates to the same degree, with terrestrial and fossorial species relying more on climate stability than arboreal species and those with generalist diets.

Main conclusions: Climate refugia held a higher number of pseudoboine snake species, particularly those occupying fossorial habitats and with specialist diets. Arboreality and diet generalization might have favored species persistence during periods of climatic change. Under current scenarios of land use change, climate change, and species population declines, understanding the role of climate refugia can promote the prioritization of such areas for conservation strategies. Furthermore, we considered how museum collections data, niche modeling and natural history notes can provide insights into biogeographical and macroecological questions regarding a diverse and infrequently encountered group of reptiles.

Download

Included in

Biology Commons

Share

COinS