If You Build It Will They Come? Snake Use of Artificial Refugia within an Industrial Scale Vineyard
Law, Valerie
Department of Natural Resource Sciences Thompson Rivers University
Kamloops, British Columbia, Canada
valerie-law@hotmail.com
Bishop, Christine
Climate Change and Environment Canada Richmond, British Columbia, Canada
Larsen, Karl W. Department of Natural Resource Sciences Thompson Rivers University
Kamloops, British Columbia, Canada klarsen@tru.ca
The Okanagan region of British Columbia (BC) has been subjected to large-scale agricultural expansion due to a land base and climate optimal for agriculture. The subsequent conversion of the native shrub steppe habitat directly impacts snake populations endemic to the area. Finding ways to enable snakes to use vineyards for hunting has obvious benefits to both snakes and vineyard production through predation on small mammals. However, for venomous rattlesnakes, this can be a significant challenge requiring ways to ensure the safety of both snakes and vineyard workers. This study has been investigating a novel way to approach this situation through the creation of artificial pockets of habitat (‘refugia’). Eight refugia composed of subterranean chambers, artificial rock piles, and native flora were built within a vineyard in Oliver, BC. Over the spring/summers of 2015-2017 chamber external air temperatures were monitored. Internal chambers became cooler like due to the establishment of vegetation provided stable temperatures below the voluntary maximum of snakes. Wildlife cameras within the chambers reveal relatively higher levels of visits by snakes (rattlesnakes, gophersnakes, and racers) in refugia near the periphery of the vineyard. Rodents (snake prey) also utilize the refugia quite extensively. However, analysis of these data revealed no significance between snake use, rodent use, or ambient air temperature. Behavioural analysis of camera footage suggests snakes are predominantly utilizing these spaces for their foraging opportunities rather than thermal refuge. Spaciousness of chambers has been suggested to reduce suitability for snake use. Overall, with further modification, these areas could offer the potential to provide spatial separation between snakes and workers.