Highway underpasses offer little fragmentation relief for desert bighorn sheep near Mojave National Preserve, CA
To improve wildlife connectivity across the U.S., managers need to identify and prioritize movement barriers in need of mitigation. Roadway barriers may be semi-permeable and allow some movement either at-grade or via non-wildlife underpasses, but permeability can depend on species-specific behavior...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
California Department of Fish and Wildlife
2024-03-01
|
| Series: | California Fish and Wildlife Journal |
| Subjects: | |
| Online Access: | https://journal.wildlife.ca.gov/2024/03/28/highway-underpasses-offer-little-fragmentation-relief-for-desert-bighorn-sheep-near-mojave-national-preserve-ca/ |
| _version_ | 1797227571067224064 |
|---|---|
| author | Christina M. Aiello Nathan L. Galloway Kristin Fratella Paige R. Prentice Neal W. Darby Debra L. Hughson Clinton W. Epps |
| author_facet | Christina M. Aiello Nathan L. Galloway Kristin Fratella Paige R. Prentice Neal W. Darby Debra L. Hughson Clinton W. Epps |
| author_sort | Christina M. Aiello |
| collection | DOAJ |
| description | To improve wildlife connectivity across the U.S., managers need to identify and prioritize movement barriers in need of mitigation. Roadway barriers may be semi-permeable and allow some movement either at-grade or via non-wildlife underpasses, but permeability can depend on species-specific behaviors and underpass characteristics. We used a combination of trail cameras and GPS collars to monitor desert bighorn (Ovis canadensis nelsoni) movement near highways and use of non-wildlife underpasses along I-15 and I-40 near Mojave National Preserve, CA. After year 1, we installed guzzlers near target underpasses in a before-after-control-impact (BACI) framework to assess changes in desert bighorn detection over 2 years post-installation. GPS collar data confirmed that desert bighorn moved close enough to 10 of 11 focal underpasses to easily access and use these structures to cross I-15 and I-40. Trail cameras at five sites recorded desert bighorn using habitat very near underpasses and even resting in a culvert tunnel, but no data indicated desert bighorn used underpasses or culverts to cross either highway. Meanwhile, species including coyote (Canis latrans), bobcat (Lynx rufus), and feral burro (Equus asinus) regularly used monitored underpasses. Adding a novel water resource did not significantly increase desert bighorn detection rate on underpass cameras at impact sites relative to control sites after 2 years, and no images suggested bighorn used the installed guzzlers. Patterns of desert bighorn habitat use in the region and lack of observed highway crossings during the study indicate generally low permeability of I-15 and I-40 for this species and a mismatch between non-wildlife underpass locations, design, and desert bighorn behavior. |
| first_indexed | 2024-04-24T14:42:55Z |
| format | Article |
| id | doaj.art-85702a755d724e0aa60ae74324065ed5 |
| institution | Directory Open Access Journal |
| issn | 2689-419X 2689-4203 |
| language | English |
| last_indexed | 2024-04-24T14:42:55Z |
| publishDate | 2024-03-01 |
| publisher | California Department of Fish and Wildlife |
| record_format | Article |
| series | California Fish and Wildlife Journal |
| spelling | doaj.art-85702a755d724e0aa60ae74324065ed52024-04-02T20:45:07ZengCalifornia Department of Fish and WildlifeCalifornia Fish and Wildlife Journal2689-419X2689-42032024-03-01110110.51492/cfwj.110.5Highway underpasses offer little fragmentation relief for desert bighorn sheep near Mojave National Preserve, CAChristina M. Aiello0https://orcid.org/0000-0002-2399-5464Nathan L. Galloway1https://orcid.org/0000-0002-0614-2988Kristin Fratella2Paige R. Prentice3Neal W. Darby4Debra L. Hughson5https://orcid.org/0000-0002-3707-1836Clinton W. Epps6https://orcid.org/0000-0001-6577-1840Oregon State UniversityNational Park ServiceOregon Department of Fish and WildlifeOregon State University and California Department of Fish and WildlifeNational Park ServiceNational Park ServiceOregon State UniversityTo improve wildlife connectivity across the U.S., managers need to identify and prioritize movement barriers in need of mitigation. Roadway barriers may be semi-permeable and allow some movement either at-grade or via non-wildlife underpasses, but permeability can depend on species-specific behaviors and underpass characteristics. We used a combination of trail cameras and GPS collars to monitor desert bighorn (Ovis canadensis nelsoni) movement near highways and use of non-wildlife underpasses along I-15 and I-40 near Mojave National Preserve, CA. After year 1, we installed guzzlers near target underpasses in a before-after-control-impact (BACI) framework to assess changes in desert bighorn detection over 2 years post-installation. GPS collar data confirmed that desert bighorn moved close enough to 10 of 11 focal underpasses to easily access and use these structures to cross I-15 and I-40. Trail cameras at five sites recorded desert bighorn using habitat very near underpasses and even resting in a culvert tunnel, but no data indicated desert bighorn used underpasses or culverts to cross either highway. Meanwhile, species including coyote (Canis latrans), bobcat (Lynx rufus), and feral burro (Equus asinus) regularly used monitored underpasses. Adding a novel water resource did not significantly increase desert bighorn detection rate on underpass cameras at impact sites relative to control sites after 2 years, and no images suggested bighorn used the installed guzzlers. Patterns of desert bighorn habitat use in the region and lack of observed highway crossings during the study indicate generally low permeability of I-15 and I-40 for this species and a mismatch between non-wildlife underpass locations, design, and desert bighorn behavior.https://journal.wildlife.ca.gov/2024/03/28/highway-underpasses-offer-little-fragmentation-relief-for-desert-bighorn-sheep-near-mojave-national-preserve-ca/connectivitycrossing structuresovis canadensismammalswildlife corridors |
| spellingShingle | Christina M. Aiello Nathan L. Galloway Kristin Fratella Paige R. Prentice Neal W. Darby Debra L. Hughson Clinton W. Epps Highway underpasses offer little fragmentation relief for desert bighorn sheep near Mojave National Preserve, CA California Fish and Wildlife Journal connectivity crossing structures ovis canadensis mammals wildlife corridors |
| title | Highway underpasses offer little fragmentation relief for desert bighorn sheep near Mojave National Preserve, CA |
| title_full | Highway underpasses offer little fragmentation relief for desert bighorn sheep near Mojave National Preserve, CA |
| title_fullStr | Highway underpasses offer little fragmentation relief for desert bighorn sheep near Mojave National Preserve, CA |
| title_full_unstemmed | Highway underpasses offer little fragmentation relief for desert bighorn sheep near Mojave National Preserve, CA |
| title_short | Highway underpasses offer little fragmentation relief for desert bighorn sheep near Mojave National Preserve, CA |
| title_sort | highway underpasses offer little fragmentation relief for desert bighorn sheep near mojave national preserve ca |
| topic | connectivity crossing structures ovis canadensis mammals wildlife corridors |
| url | https://journal.wildlife.ca.gov/2024/03/28/highway-underpasses-offer-little-fragmentation-relief-for-desert-bighorn-sheep-near-mojave-national-preserve-ca/ |
| work_keys_str_mv | AT christinamaiello highwayunderpassesofferlittlefragmentationrelieffordesertbighornsheepnearmojavenationalpreserveca AT nathanlgalloway highwayunderpassesofferlittlefragmentationrelieffordesertbighornsheepnearmojavenationalpreserveca AT kristinfratella highwayunderpassesofferlittlefragmentationrelieffordesertbighornsheepnearmojavenationalpreserveca AT paigerprentice highwayunderpassesofferlittlefragmentationrelieffordesertbighornsheepnearmojavenationalpreserveca AT nealwdarby highwayunderpassesofferlittlefragmentationrelieffordesertbighornsheepnearmojavenationalpreserveca AT debralhughson highwayunderpassesofferlittlefragmentationrelieffordesertbighornsheepnearmojavenationalpreserveca AT clintonwepps highwayunderpassesofferlittlefragmentationrelieffordesertbighornsheepnearmojavenationalpreserveca |