Presentation Title

Ecology of Xantusia vigilis: Modeling the Climatic Niche of a Desert Lizard

Faculty Mentor

Stephen Adolph

Start Date

23-11-2019 1:15 PM

End Date

23-11-2019 1:30 PM

Location

Markstein 213

Session

oral 3

Type of Presentation

Oral Talk

Subject Area

biological_agricultural_sciences

Abstract

Xantusia vigilis, more commonly known as desert night lizards, live abundantly in arid regions of southwestern North America. They avoid exposure to extreme temperatures by lodging under rocks and branches. Previous research shows that fecundity of X. vigilis positively correlates with winter precipitation. Anthropogenic climate change is causing an unprecedented increase in Arctic temperatures, which could cause less precipitation in Southwest North America. Recent publications using correlative species distribution models (SDMs) predict that Joshua trees, X. vigilis’s primary habitat, may become extinct due to climate-induced range shifts in the near future. These changing climate conditions could also shift the distribution of X. vigilis. To test this hypothesis, we modeled the current distribution of X. vigilis and projected the models into the future to determine their potential range shift. We used three different SDM algorithms: Maxent, general linear regression, and random forest, which correlate rasterized environmental data with 1583 distinct occurrence locations of X. vigilis. We used 1 km2-resolution rasters of 10 independent BIOCLIM metrics (averaged from 1970-2000) and elevation. The results from our SDM models are very consistent with published geographic ranges. The significant overlap between models reflects the narrow environmental niche occupied by X. Vigilis, distinguishing areas with dry summers and cold winters as suitable. Furthermore, we observe similarity between the niches of X. vigilis and Y. brevifolia through spatial overlap and principal component analysis. This implies that X. vigilis often inhabit, but do not depend exclusively on, Y. brevifolia for shelter. Model projection to 2070 reveals a significant range shift northeast. Assuming that X. vigilis have a small dispersal potential, their feasible range could constrict by as much as 50 percent. In conjunction with Y. Brevifolia’s range constriction and resource scarcity in extreme droughts these results reveal an uncertain future for the species.

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Nov 23rd, 1:15 PM Nov 23rd, 1:30 PM

Ecology of Xantusia vigilis: Modeling the Climatic Niche of a Desert Lizard

Markstein 213

Xantusia vigilis, more commonly known as desert night lizards, live abundantly in arid regions of southwestern North America. They avoid exposure to extreme temperatures by lodging under rocks and branches. Previous research shows that fecundity of X. vigilis positively correlates with winter precipitation. Anthropogenic climate change is causing an unprecedented increase in Arctic temperatures, which could cause less precipitation in Southwest North America. Recent publications using correlative species distribution models (SDMs) predict that Joshua trees, X. vigilis’s primary habitat, may become extinct due to climate-induced range shifts in the near future. These changing climate conditions could also shift the distribution of X. vigilis. To test this hypothesis, we modeled the current distribution of X. vigilis and projected the models into the future to determine their potential range shift. We used three different SDM algorithms: Maxent, general linear regression, and random forest, which correlate rasterized environmental data with 1583 distinct occurrence locations of X. vigilis. We used 1 km2-resolution rasters of 10 independent BIOCLIM metrics (averaged from 1970-2000) and elevation. The results from our SDM models are very consistent with published geographic ranges. The significant overlap between models reflects the narrow environmental niche occupied by X. Vigilis, distinguishing areas with dry summers and cold winters as suitable. Furthermore, we observe similarity between the niches of X. vigilis and Y. brevifolia through spatial overlap and principal component analysis. This implies that X. vigilis often inhabit, but do not depend exclusively on, Y. brevifolia for shelter. Model projection to 2070 reveals a significant range shift northeast. Assuming that X. vigilis have a small dispersal potential, their feasible range could constrict by as much as 50 percent. In conjunction with Y. Brevifolia’s range constriction and resource scarcity in extreme droughts these results reveal an uncertain future for the species.