Spatial patterns of reproduction suggest marginal habitat limits continued range expansion of black bears at a forest‐desert ecotone
Abstract Investigating spatial patterns of animal occupancy and reproduction in peripheral populations can provide insight into factors that form species range boundaries. Following historical extirpation, American black bears (Ursus americanus) recolonized the western Great Basin in Nevada from the...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2023-11-01
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| Series: | Ecology and Evolution |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/ece3.10658 |
| _version_ | 1797448602047479808 |
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| author | Sean M. Sultaire Robert A. Montgomery Patrick J. Jackson Joshua J. Millspaugh |
| author_facet | Sean M. Sultaire Robert A. Montgomery Patrick J. Jackson Joshua J. Millspaugh |
| author_sort | Sean M. Sultaire |
| collection | DOAJ |
| description | Abstract Investigating spatial patterns of animal occupancy and reproduction in peripheral populations can provide insight into factors that form species range boundaries. Following historical extirpation, American black bears (Ursus americanus) recolonized the western Great Basin in Nevada from the Sierra Nevada during the late 1900s. This range expansion, however, has not continued further into the Great Basin despite the presence of additional habitat. We aimed to quantify whether reduced reproduction toward the range edge contributes to this range boundary. We analyzed black bear detections from 100 camera traps deployed across black bear distribution in western Nevada using a multistate occupancy model that quantified the probability of occupancy and reproduction (i.e., female bears with cubs occupancy) in relation to changes in habitat type and habitat amount toward the range boundary. We detected a strong effect of habitat amount and habitat type on the probability of black bear occupancy and reproduction. At similar levels of landscape‐scale habitat amount (e.g., 50%), estimated probability of occupancy for adult bears in piñon‐juniper woodlands near the range boundary was 0.39, compared to ~1.0 in Sierra Nevada mixed‐conifer forest (i.e., core habitat). Furthermore, estimated probability of cub occupancy, conditional on adult bear occupancy, in landscapes with 50% habitat was 0.32 in Great Basin piñon‐juniper woodlands, compared to 0.92 in Sierra Nevada mixed‐conifer forest. Black bear range in the western Great Basin conforms to the center–periphery hypothesis, with piñon‐juniper woodland at the range edge supporting ecologically marginal habitat for the species compared to habitat in the Sierra Nevada. Further geographic expansion of black bears in the Great Basin may be limited by lower occupancy of reproducing females in piñon‐juniper woodland. Center–periphery range dynamics may be common in large carnivore species, as their dispersal ability allows them to colonize low‐quality habitat near range edges. |
| first_indexed | 2024-03-09T14:13:53Z |
| format | Article |
| id | doaj.art-8f8d6bb645dd49ab97f6325cbf6827ab |
| institution | Directory Open Access Journal |
| issn | 2045-7758 |
| language | English |
| last_indexed | 2024-03-09T14:13:53Z |
| publishDate | 2023-11-01 |
| publisher | Wiley |
| record_format | Article |
| series | Ecology and Evolution |
| spelling | doaj.art-8f8d6bb645dd49ab97f6325cbf6827ab2023-11-29T05:44:08ZengWileyEcology and Evolution2045-77582023-11-011311n/an/a10.1002/ece3.10658Spatial patterns of reproduction suggest marginal habitat limits continued range expansion of black bears at a forest‐desert ecotoneSean M. Sultaire0Robert A. Montgomery1Patrick J. Jackson2Joshua J. Millspaugh3Wildlife Biology Program University of Montana Missoula Montana USADepartment of Biology University of Oxford Oxford UKNevada Department of Wildlife Reno Nevada USAWildlife Biology Program University of Montana Missoula Montana USAAbstract Investigating spatial patterns of animal occupancy and reproduction in peripheral populations can provide insight into factors that form species range boundaries. Following historical extirpation, American black bears (Ursus americanus) recolonized the western Great Basin in Nevada from the Sierra Nevada during the late 1900s. This range expansion, however, has not continued further into the Great Basin despite the presence of additional habitat. We aimed to quantify whether reduced reproduction toward the range edge contributes to this range boundary. We analyzed black bear detections from 100 camera traps deployed across black bear distribution in western Nevada using a multistate occupancy model that quantified the probability of occupancy and reproduction (i.e., female bears with cubs occupancy) in relation to changes in habitat type and habitat amount toward the range boundary. We detected a strong effect of habitat amount and habitat type on the probability of black bear occupancy and reproduction. At similar levels of landscape‐scale habitat amount (e.g., 50%), estimated probability of occupancy for adult bears in piñon‐juniper woodlands near the range boundary was 0.39, compared to ~1.0 in Sierra Nevada mixed‐conifer forest (i.e., core habitat). Furthermore, estimated probability of cub occupancy, conditional on adult bear occupancy, in landscapes with 50% habitat was 0.32 in Great Basin piñon‐juniper woodlands, compared to 0.92 in Sierra Nevada mixed‐conifer forest. Black bear range in the western Great Basin conforms to the center–periphery hypothesis, with piñon‐juniper woodland at the range edge supporting ecologically marginal habitat for the species compared to habitat in the Sierra Nevada. Further geographic expansion of black bears in the Great Basin may be limited by lower occupancy of reproducing females in piñon‐juniper woodland. Center–periphery range dynamics may be common in large carnivore species, as their dispersal ability allows them to colonize low‐quality habitat near range edges.https://doi.org/10.1002/ece3.10658black bear reproductioncenter–periphery hypothesisGreat Basinmultistate occupancy modelpiñon‐juniper woodlandrange boundary |
| spellingShingle | Sean M. Sultaire Robert A. Montgomery Patrick J. Jackson Joshua J. Millspaugh Spatial patterns of reproduction suggest marginal habitat limits continued range expansion of black bears at a forest‐desert ecotone Ecology and Evolution black bear reproduction center–periphery hypothesis Great Basin multistate occupancy model piñon‐juniper woodland range boundary |
| title | Spatial patterns of reproduction suggest marginal habitat limits continued range expansion of black bears at a forest‐desert ecotone |
| title_full | Spatial patterns of reproduction suggest marginal habitat limits continued range expansion of black bears at a forest‐desert ecotone |
| title_fullStr | Spatial patterns of reproduction suggest marginal habitat limits continued range expansion of black bears at a forest‐desert ecotone |
| title_full_unstemmed | Spatial patterns of reproduction suggest marginal habitat limits continued range expansion of black bears at a forest‐desert ecotone |
| title_short | Spatial patterns of reproduction suggest marginal habitat limits continued range expansion of black bears at a forest‐desert ecotone |
| title_sort | spatial patterns of reproduction suggest marginal habitat limits continued range expansion of black bears at a forest desert ecotone |
| topic | black bear reproduction center–periphery hypothesis Great Basin multistate occupancy model piñon‐juniper woodland range boundary |
| url | https://doi.org/10.1002/ece3.10658 |
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