"Wolves from heavily hunted populations in northern Canada show elevated stress and reproductive hormones — physiological effects that could have evolutionary implications — according to a study published Wednesday in the scientific journal Functional Ecology. Hunting can disrupt a wolf pack’s complex social structure, alter normal reproductive behaviour and introduce chronic stress that “may have evolutionary consequences,” the study found. Hunting can also decrease pack size, resulting in altered predation patterns, increased time spent defending kill sites from scavengers and may lead to increased conflict with humans and livestock, the study added." - Jessie

" A collaboration of researchers from B.C., Alberta, and Israel studied hair samples from 103 tundra/taiga wolves from Nunavut and the Northwest Territories against 45 wolves from the boreal forests of Alberta and the Northwest Territories. The tundra-taiga wolves hunt primarily caribou and live in an open landscape where they are easily killed by hunters on snowmobiles. The boreal wolves eat primarily moose and live in a forest landscape where they are killed at a much reduced rate by traps and snares. Wolves have a complex social structure, with usually just the dominant pair in a pack having one litter of pups per year. Large-scale killing of wolves disrupts that structure, leading to increased reproductive rates and altered genetic structure and behaviour. Heather Bryan, who conducted the research as part of her PhD research at the University of Calgary, said the hormones are found in minute amounts in the hair, comparable to measuring 10 granules of salt dissolved in 30 Olympic-sized swimming pools. “Despite the low concentrations, our measurements on hair revealed that wolves from heavily hunted populations had higher progesterone, testosterone, and cortisol,” she said." - Jessie

" Stress and reproductive hormones accumulate in growing hair from the blood vessel that supplies the hair follicle and surrounding glands. There was no significant difference between wolves with dark and light-coloured fur. Elevated levels of the reproductive hormone, testosterone, in both male and female wolves are thought to be linked to hunting. Increased levels of progesterone, a hormone produced during pregnancy, likely reflects an unusually higher proportion of breeding females. States the study: “When social structure is disrupted, multiple litters per social group become more common, in part because dominant individuals can no longer prevent subordinates from breeding.” Participants included University of Calgary, Raincoast Conservation Foundation, University of Victoria, Hakai Beach Institute, and Israel’s Bar-Ilan University. Paul Paquet, adjunct geography professor at the University of Victoria, noted: “The effects of stress are often subtle, but the resulting harm can be acute, chronic, and permanent, sometimes spanning generations.” A study of a smaller population of 30 boreal wolves subject to a predator-control program to protect endangered mountain caribou farther south in Alberta also showed elevated levels of cortisol, a stress hormone." - Jessie