Lack of Reproduction in Muskoxen and Arctic Hares Caused by Early Winter

A lack of young muskoxen (Ovibos moschatus) and arctic hares (Lepus arcticus)
in the Eureka area of Ellesmere Island, Northwest Territories (now Nunavut),
Canada, was observed during summer 1998, in contrast to most other years since
1986. Evidence of malnourished muskoxen was also found. Early winter weather
and a consequent 50% reduction of the 1997 summer replenishment period appeared
to be the most likely cause, giving rise to a new hypothesis about conditions
that might cause adverse demographic effects in arctic herbivores.

The study area included a 150 km2 region of the Fosheim Peninsula in a 180o arc
north of Eureka, Ellesmere Island, Nunavut, Canada (all within about 9 km of
80oN, 86oW). The area, extending from Eureka Sound to Remus Creek and from
Slidre Fiord to Eastwind Lake, included shoreline, hills, lowlands, creek
bottoms, and the west side of Blacktop Ridge. An associate, Layne Adams, and I
spent 1-11 July 1998 in this area on all-terrain vehicles, following a pair of
wolves Canis lupus (Mech, 1994). Adams and I also surveyed the surrounding area
with binoculars for prey animals, in much the same manner that my assistants
and I have practiced for one to six weeks each summer in the same area since
1986 (Mech, 1995, 1997). Because both muskoxen and arctic hares were common
residents of the area during most years and were not the focus of our studies,
no standardized counts were made. However, general field notes were sufficient
to document that during most summers both species and their young were present.