Elevated road segment (ERS) passage design may provide enhanced connectivity for amphibians, reptiles, and small mammals
IntroductionDesigns for safe and effective road crossing structures for small animals are typically under-road microtunnels and culverts which have varying levels of effectiveness reported in the scientific literature. Many species, particularly migratory amphibians, may have limited ability to find...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2023-05-01
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| Series: | Frontiers in Ecology and Evolution |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/fevo.2023.1145322/full |
| _version_ | 1797821461344288768 |
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| author | Cheryl S. Brehme Stephanie Barnes Brittany Ewing Philip Gould Cassie Vaughan Michael Hobbs Charles Tornaci Sarah Holm Hanna Sheldon Jon Fiutak Robert N. Fisher |
| author_facet | Cheryl S. Brehme Stephanie Barnes Brittany Ewing Philip Gould Cassie Vaughan Michael Hobbs Charles Tornaci Sarah Holm Hanna Sheldon Jon Fiutak Robert N. Fisher |
| author_sort | Cheryl S. Brehme |
| collection | DOAJ |
| description | IntroductionDesigns for safe and effective road crossing structures for small animals are typically under-road microtunnels and culverts which have varying levels of effectiveness reported in the scientific literature. Many species, particularly migratory amphibians, may have limited ability to find and use passages if they are too far apart, resulting in substantial barrier effects.MethodsWe designed a novel open elevated passage (elevated road segment: ERS), similar to a low terrestrial bridge, that could theoretically be built to any length based upon species needs and movement characteristics. A 30 m length prototype ERS was installed along a forest road with a history of amphibian road mortality in Sierra National Forest, Fresno County, CA, USA. From 2018 to 2021, we monitored small animal activity under the ERS in relation to surrounding roadside and forest habitats using active infrared cameras.ResultsWe documented a total of 8,815 unique use events, using species specific independence criteria, across 22 species of amphibians (3), reptiles (4), and small mammals (15). Poisson regression modeling of taxonomic group activity under the ERS, roadside and forest, showed that amphibian activity was highest in the forest habitat, no differences were observed for reptiles, and small mammal activity was highest under the ERS. However, mean activity estimates under the ERS were equal to or greater than the open roadside habitat for all 22 species, suggesting that adding cover objects, such as downed logs and vegetation may further enhance passage use.DiscussionOverall, results showed that the design of the ERS crossing has potential to provide high connectivity for a wide range of amphibian, reptile, and small mammal species while reducing road mortality. ERS systems can also be used in areas with challenging terrain and other hydrological and environmental constraints. Incorporating current road ecology science, we provide supplemental ERS concept designs for secondary roads, primary roads and highways to help increase the options available for road mitigation planning for small animals. |
| first_indexed | 2024-03-13T09:53:02Z |
| format | Article |
| id | doaj.art-e323d1f998c9434796f49fcd698b7115 |
| institution | Directory Open Access Journal |
| issn | 2296-701X |
| language | English |
| last_indexed | 2024-03-13T09:53:02Z |
| publishDate | 2023-05-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Ecology and Evolution |
| spelling | doaj.art-e323d1f998c9434796f49fcd698b71152023-05-24T05:33:18ZengFrontiers Media S.A.Frontiers in Ecology and Evolution2296-701X2023-05-011110.3389/fevo.2023.11453221145322Elevated road segment (ERS) passage design may provide enhanced connectivity for amphibians, reptiles, and small mammalsCheryl S. Brehme0Stephanie Barnes1Brittany Ewing2Philip Gould3Cassie Vaughan4Michael Hobbs5Charles Tornaci6Sarah Holm7Hanna Sheldon8Jon Fiutak9Robert N. Fisher10U.S. Geological Survey, Western Ecological Research Center, San Diego, CA, United StatesU.S. Forest Service, Sierra National Forest, Prather, CA, United StatesU.S. Geological Survey, Western Ecological Research Center, San Diego, CA, United StatesU.S. Geological Survey, Western Ecological Research Center, San Diego, CA, United StatesU.S. Forest Service, Sierra National Forest, Prather, CA, United StatesHobbs Ecology, San Jose, CA, United StatesDokken Engineering, San Diego, CA, United StatesDokken Engineering, San Diego, CA, United StatesDokken Engineering, San Diego, CA, United StatesAnthony Hardwood Composites and Emtek Matting Solutions, Sheridan, AR, United StatesU.S. Geological Survey, Western Ecological Research Center, San Diego, CA, United StatesIntroductionDesigns for safe and effective road crossing structures for small animals are typically under-road microtunnels and culverts which have varying levels of effectiveness reported in the scientific literature. Many species, particularly migratory amphibians, may have limited ability to find and use passages if they are too far apart, resulting in substantial barrier effects.MethodsWe designed a novel open elevated passage (elevated road segment: ERS), similar to a low terrestrial bridge, that could theoretically be built to any length based upon species needs and movement characteristics. A 30 m length prototype ERS was installed along a forest road with a history of amphibian road mortality in Sierra National Forest, Fresno County, CA, USA. From 2018 to 2021, we monitored small animal activity under the ERS in relation to surrounding roadside and forest habitats using active infrared cameras.ResultsWe documented a total of 8,815 unique use events, using species specific independence criteria, across 22 species of amphibians (3), reptiles (4), and small mammals (15). Poisson regression modeling of taxonomic group activity under the ERS, roadside and forest, showed that amphibian activity was highest in the forest habitat, no differences were observed for reptiles, and small mammal activity was highest under the ERS. However, mean activity estimates under the ERS were equal to or greater than the open roadside habitat for all 22 species, suggesting that adding cover objects, such as downed logs and vegetation may further enhance passage use.DiscussionOverall, results showed that the design of the ERS crossing has potential to provide high connectivity for a wide range of amphibian, reptile, and small mammal species while reducing road mortality. ERS systems can also be used in areas with challenging terrain and other hydrological and environmental constraints. Incorporating current road ecology science, we provide supplemental ERS concept designs for secondary roads, primary roads and highways to help increase the options available for road mitigation planning for small animals.https://www.frontiersin.org/articles/10.3389/fevo.2023.1145322/fullroad ecologyroad crossingpassageherpetofaunadesigntunnel |
| spellingShingle | Cheryl S. Brehme Stephanie Barnes Brittany Ewing Philip Gould Cassie Vaughan Michael Hobbs Charles Tornaci Sarah Holm Hanna Sheldon Jon Fiutak Robert N. Fisher Elevated road segment (ERS) passage design may provide enhanced connectivity for amphibians, reptiles, and small mammals Frontiers in Ecology and Evolution road ecology road crossing passage herpetofauna design tunnel |
| title | Elevated road segment (ERS) passage design may provide enhanced connectivity for amphibians, reptiles, and small mammals |
| title_full | Elevated road segment (ERS) passage design may provide enhanced connectivity for amphibians, reptiles, and small mammals |
| title_fullStr | Elevated road segment (ERS) passage design may provide enhanced connectivity for amphibians, reptiles, and small mammals |
| title_full_unstemmed | Elevated road segment (ERS) passage design may provide enhanced connectivity for amphibians, reptiles, and small mammals |
| title_short | Elevated road segment (ERS) passage design may provide enhanced connectivity for amphibians, reptiles, and small mammals |
| title_sort | elevated road segment ers passage design may provide enhanced connectivity for amphibians reptiles and small mammals |
| topic | road ecology road crossing passage herpetofauna design tunnel |
| url | https://www.frontiersin.org/articles/10.3389/fevo.2023.1145322/full |
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