RANGE EXPANSION OF COYOTES, CANIS LATRANS, THREATENS A REMNANT HERD OF CARIBOU, RANGIFER TARANDUS, IN SOUTHEASTERN QUEBEC

The autumn calfcow ratio of a remnant Caribou herd in Gaspesie Park, Q uebec, declined from approximate to 20-30 calves per 100 females in 19 84-1985 to only four in 1987, after Coyotes colonized the area. Twenty adult female Caribou were radiotagged in November of the same year, a nd examination of blood samples and vaginal swabs did not detect disea ses likely to affect fecundity. The following spring, 13 of 19 (68%) r adio-collared Caribou were observed to be followed by a calf at the ti me of parturition, but only one neonate survived until the following a utumn. In 1989 and 1490, 25 radio-tagged calves were monitored and 16 of them died in the course of the summer. Likely cause of death was de termined for 11 cases and suggested that Coyotes were responsible for 7 deaths, Black Bears for 3 and Golden Eagle for 1. The mortality rate of neonates was higher for the Caribou group inhabiting the eastern p ortion of the park than for the other group which used the centre of t he park. Calves surviving until autumn exhibited low mortality during their first winter of life: 8 of 9 survived this season during three w inters. Between 1987 and 1992, annual survival of adults exceeded 0.90 on average; most deaths occurred during the harsh winter of 1990-1991 , and Coyote predation was possible in a maximum of two of six cases. Predators were reduced in the park and surroundings between 1990 and 1 992 in order to improve calf survival. Recruitment was sufficient to r eplace mortality after 1988 for the Caribou group occupying the centre of the park, but it remained at about 10 calves:100 females until 199 2 for the group inhabiting the eastern part of the park, at which time calf survival finally improved.