Population demography of high arctic caribou on Banks and Melville Islands

Nicholas C Larter,John A Nagy

doi:10.7557/2.23.5.1696

Abstract

Caribou numbers, Rangifer tarandus pearyi, (excluding calves) on Banks Island were estimated (standard error of the estimate) at 1005 (SE&plusmn;133) in 1992, 709 (SE&plusmn;128) in 1994 and 436 (SE&plusmn;71) in 1998; no paired estimates were different (P&lt;0.05). On Melville Island caribou numbers were similar in 1987 and 1997 with estimates of 729 (SE&plusmn;104) and 787 (SE&plusmn;97), respectively. We conducted annual sex and age classification surveys during July on Banks Island from 1994-2000 and on Melville Island from 1998-2000. The number of calves per 100 &gt;two-year-old females ranged from 24.0 in 1994 to 74.3 in 1998 on Banks Island, and from 44.8 in 1999 to 80.0 in 1998 on Melville Island. Recruitment rate ranged from 18.6% during 1997/1998 to 27.5% during 1999/2000 on Banks Island and from 16.7% during 1997/1998 to 25.0% during 1999/2000 on Melville Island. There has been an increasing trend in the rate of recruitment on both islands during the last three years of the study.

Highlights

Peary caribou (Rangifer tarandus pearyi) inhabit the Canadian High Arctic and were designated as an endangered subspecies by the Committee on the Status of Endangered Species in Canada (COSEWIC) in 1991
Banks Island was stratified into eight strata based upon a combination of geographic area and muskox density determined from previous surveys
Island (Table 1) were excluded from the calcula¬ calf production has been highly variable for both tions

Summary

Introduction

Peary caribou (Rangifer tarandus pearyi) inhabit the Canadian High Arctic and were designated as an endangered subspecies by the Committee on the Status of Endangered Species in Canada (COSEWIC) in 1991. Current estimates of Peary caribou numbers are lower than the first estimates determined in the 1960s and 1970s. Severe winter weather has been associated with die-offs throughout the High Arctic and is believed to be the major cause of the reduction in numbers (Parker et al, 1975; Gunn, 1992). Data to critically assess causes are lacking. Over much of the Peary caribou range few systematic population surveys have been conducted and the periods between surveys can be measured in decades. Data on estimates of calf production, survival and recruitment are limited (Larter & Nagy, 2000a).

Methods

Results

Conclusion