An Unusual Host-Parasite Relationship: Factors Affecting the Rate at Which Burrowing Owls are Bugged by Fleas
Abstract
An interesting host-parasite relationship occurs between Western Burrowing Owls (Athene cunicularia hypugaea) and Pulex irritans (Siphonaptera: Family Pulidae), commonly named the “human flea.” P. irritans is a cosmopolitan species of flea that typically parasitizes mammals, which makes its association with Burrowing Owls remarkable. Moreover, the association between P. irritans and Burrowing Owls essentially occurs only in the Pacific Northwest region of the United States, even though both species have broader distributions. Molecular studies confirm that P. irritans feed from Burrowing Owls, so these fleas are truly parasitic on owls, and that Burrowing Owls are not simply phoretic hosts. Although this association was first reported in the early 1900s, most aspects remain poorly understood. We were interested in understanding factors underlying spatial and temporal variation in fleas on Burrowing Owls. Using long-term data (1997 - 2023, > 900 nests) we explored patterns in P. irritans abundance on Burrowing Owl nestlings in the Morley Nelson Snake River Birds of Prey National Conservation Area, located in southwestern Idaho, U.S.A. We found that fleas declined over this time period, winter precipitation and summer temperature affected flea abundance, individual nest sites varied across time in flea abundance, and flea abundance did not differ for sites in agricultural and non-agricultural settings. Our poster explores these and other relationships about factors affecting distribution and abundance of P. irritans on Burrowing Owl nestlings.
An Unusual Host-Parasite Relationship: Factors Affecting the Rate at Which Burrowing Owls are Bugged by Fleas
An interesting host-parasite relationship occurs between Western Burrowing Owls (Athene cunicularia hypugaea) and Pulex irritans (Siphonaptera: Family Pulidae), commonly named the “human flea.” P. irritans is a cosmopolitan species of flea that typically parasitizes mammals, which makes its association with Burrowing Owls remarkable. Moreover, the association between P. irritans and Burrowing Owls essentially occurs only in the Pacific Northwest region of the United States, even though both species have broader distributions. Molecular studies confirm that P. irritans feed from Burrowing Owls, so these fleas are truly parasitic on owls, and that Burrowing Owls are not simply phoretic hosts. Although this association was first reported in the early 1900s, most aspects remain poorly understood. We were interested in understanding factors underlying spatial and temporal variation in fleas on Burrowing Owls. Using long-term data (1997 - 2023, > 900 nests) we explored patterns in P. irritans abundance on Burrowing Owl nestlings in the Morley Nelson Snake River Birds of Prey National Conservation Area, located in southwestern Idaho, U.S.A. We found that fleas declined over this time period, winter precipitation and summer temperature affected flea abundance, individual nest sites varied across time in flea abundance, and flea abundance did not differ for sites in agricultural and non-agricultural settings. Our poster explores these and other relationships about factors affecting distribution and abundance of P. irritans on Burrowing Owl nestlings.