|
|
Journal
Publications
Hoberg E.P., Kutz S.J., Nagy J., Jenkins E.,
Elkin B., Branigan M., and Cooley D. 2002 Protostrongylus stilesi
(Nematoda: Protostrongylidae): Ecological Isolation and Putative
Host-Switcing Between Dall’s Sheep and Muskoxen in a Contact Zone
Comparative Parasitology 69(1)
(PDF
= 91 KB)
Abstract:
The occurrence of Protostrongylus stilesi in a
population of introduced muskoxen, Ovibos moschatus wardi, on the Arctic
Coastal Plain, Yukon Territory (YT) and Northwest Territories (NT), Canada,
is consistent with a contemporary colonization event from Dall’s sheep, Ovis
dalli dalli, which indicates that host specificity may be ecologically based
and contextual for this parasite. Colonization of muskoxen by P. stilesi may
be a predictable event in zones of sympatry with Dall’s sheep; exposure to
infection may coincide with occupation of winter ranges of Dall’s sheep by
muskoxen during the summer season. Disruption of contemporary ecological
isolating barriers can result from anthropogenically or climatologically
driven habitat perturbation, and result from management practices that
influence the distribution of ungulate hosts. Thus, if zones of contact
become more extensive or the temporal limits on allopatry are relaxed, we
may observe increasing instances of host switching by parasites or pathogens
at the interface of newly emerging ecotones. Impacts to northern systems
linked to climatologically and anthropogenically driven global change and
the effects of management must be tracked within the context of biodiversity
survey and inventory and archival collections, as foundations for monitoring
ecosystem-level perturbations. A developing interface for muskoxen, wild
sheep, and parasites along the Mackenzie River ecotone represents a natural
model or field laboratory to examine these processes. Additonally,
lungworms, Protostrongylus spp., had not been reported in muskoxen, and a
new geographic record for
this nematode was established in Dall’s sheep from the northern Richardson
Mountains, NT. |
