An Ecological Niche Model to Predict Range Expansion of the Eastern Gray Squirrel in California
Open accessAbstract
The eastern gray squirrel, Sciurus carolinensis (EGS) has been introduced to California and has expanded its geographic range since initial introductions. In this study we projected the potential future geographic range of the EGS in California using Maxent to create an ecological niche model. Location data were obtained over the time period of 2004–2015 from museum specimens, wildlife rehabilitation centers, the California Department of Public Health, the California Roadkill Observation System, and non-iNaturalist citizen science observations. Research grade data from iNaturalist was obtained over the time period of 2004–2018. Range and habitat suitability maps were developed by mapping in ArcGIS. Three threshold selection methods were used to create different estimates of the potential future range of the EGS in California. The first method used the 10th percentile logistic threshold, the second used the minimum training presence logistic threshold, and the third used Jenks Natural Breaks. We propose that Jenks Natural Breaks has distinct advantages over the other two methods for estimating the potential future range of the introduced EGS in California, because it provides information on the habitat suitability ranking throughout California, whereas the other methods only provide a binary suitable/unsuitable map.
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Eastern gray squirrels are extremely common across the United States and are currently expanding their range.
“Eastern gray squirrels are extremely common across the United States and are currently expanding their range (Benson, 2013;Creley et al., 2019).”
From Of Rarity and Symbolism: Understanding Human Perceptions of Charismatic Color Morphs (2024) · cites this paper as Creley et al., 2019
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Huang, S.-Y., Zhu, J.-J., Zhai, K., Wang, Y., Wei, H.-X., Xu, Z., & Gu, X.-R. (2022) · Forests · doi:10.3390/f13081192 · Cited by 33 · see citing works
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Comia-Geneta, G., Reyes-Haygood, S. J., Salazar-Golez, N. L., Seladis-Ocampo, N. A., Samuel-Sualibios, M. R., Dagamac, N. H., & Buebos-Esteve, D. (2024) · Modeling Earth Systems and Environment · doi:10.1007/s40808-024-02005-3 · Cited by 16
“Jenks was used because its classifications are grounded in the natural groupings of the data (Creley et al. 2019).”
Du, Y.-B., Wang, X., Ashraf, S., Tu, W.-S., Xi, Y., Cui, R., Chen, S., Yu, J.-J., Han, L., Gu, S.-M., et al. (2024) · Global Change Biology · doi:10.1111/gcb.17137 · Cited by 16 · see citing works
Zhao, X., Zheng, Y., Wang, W., Wang, Z., Zhang, Q., Liu, J.-C., & Zhang, C.-T. (2023) · Forests · doi:10.3390/f14020438 · Cited by 13
Continent-wide recent emergence of a global pathogen in African amphibians
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Tran, T., Carter, B. E., & Vardaro, J. C. C. (2022) · Biological Invasions · doi:10.1007/s10530-022-02859-7 · Cited by 12
Of Rarity and Symbolism: Understanding Human Perceptions of Charismatic Color Morphs
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“Eastern gray squirrels are extremely common across the United States and are currently expanding their range (Ben-son, 2013; Creley et al., 2019).”
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“As some research demonstrated, the fixed threshold approach is not optimal [19–21], thus the MaxEnt results here were imported into ArcGIS 10.4.1 and reclassified into five categories (Very Low, Low, Medium, High, Very High) representing the suitability values using Jenks Natural Breaks Classification [22,23].”
MethodInfluentialChen, S., Chen, R., Zeng, X., Chen, X., Qin, X., Zhang, Z.-X., & Sun, Y. (2022) · Forests · doi:10.3390/f13081239 · Cited by 5
Exploring the distribution and habitat preferences of Polytrichaceae (Bryophyta) in Tibet, China
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Richmond, J. Q., Kingston, J., Ewing, B. A. I., Bear, W. M., Hathaway, S. A., Lee, C., Swift, C. C., Preston, K. L., Schultz, A. J., Kus, B. E., et al. (2023) · Bulletin Southern California Academy of Sciences · doi:10.3160/0038-3872-122.2.101 · Cited by 1 · see citing works
“…al. 2010; Muchlinski and Garcia 2017), its capacity to use corridor habitat to expand eastward away from the coast (King 2004; Tremor et al. 2017; Creley et al. 2019), combined with its known potential to displace the native Western Gray Squirrel should the two come into contact (Sciurus…”
Background
- Authors
- Creley, C. M., Shilling, F. M., & Muchlinski, A. E.
- Affiliations
- California State University Los Angeles (US)
- University of California, Davis (US)
- Corresponding author
- Creley, Carly M.
- ORCID
- Shilling, Fraser M.
- Venue
- Bulletin, Southern California Academy of Sciences
- Published
- 2019-04-17
- Volume
- 118
- Issue
- 1
- Pages
- 58
- ISSN
- 0038-3872 (ISSN-L)
- OpenAlex
- W2939488305
- Cited by
- 14
- References
- 12
- Citations by year
- 2025: 1 · 2024: 4 · 2023: 5 · 2022: 2 · 2021: 2
- FWCI
- 1.51
- Type
- journal article
- Language
- en
- Open access
- Licence
- cc-by-nc-sa
- Locations
- Bulletin Southern California Academy of Sciences (publishedVersion)
- Occidental College Scholar (Occidental College) (submittedVersion)
- Biodiversity Heritage Library (Smithsonian Institution) (submittedVersion, cc-by-nc-sa)
- Topics
- Physical Sciences › Environmental Science › Ecological Modeling › Species Distribution and Climate Change
- Physical Sciences › Environmental Science › Ecology › Animal Ecology and Behavior Studies
- Physical Sciences › Environmental Science › Ecology › Wildlife Ecology and Conservation
- Keywords
- Sciurus carolinensis, introduced species, range expansion, ecological niche modeling, MaxEnt, habitat suitability, Jenks natural breaks, citizen science observations, California
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