Dramatic decline in wildlife: Report
WWF-Canada study finds populations among species on the decline have dropped by 83 per cent on average
A new report from WWF-Canada paints a dire picture of Canada’s wildlife, finding that fully half of the species monitored have declined since 1970.
Among the species that are on the decline, populations have dropped by a whopping 83 per cent on average, according to the living planet index, a measure of biodiversity based on population trends.
“The sheer magnitude of it is really very, very sobering,” said David Miller, president and CEO of WWF-Canada.
The study includes iconic species like the woodland caribou, which has been losing habitat to logging, mining, and oil and gas development, as well as lesser-known species like the piping plover, a small shorebird that’s dropping in numbers due to development and beach use.
Altogether, the report includes 3,689 populations of 903 vertebrate species in Canada that have been monitored between 1970 and 2014. Researchers compiled existing data from government databases, academic analyses and community-based monitoring initiatives. It’s the first report of its kind in a decade.
“Pretty much in every region, there’s some group of species that is declining,” said James Snider, vice-president of science, research and innovation for WWFCanada.
The major threats to biodiversity, according to the report, are habitat loss, climate change, pollution, unsustainable harvesting and invasive species.
It’s not all bad news, however. Though the report finds that 451 monitored species are on the decline, another 407 have increased in abundance since 1970. Some of those are animals that have adapted well to living alongside humans. Others have been targeted by specific conservation efforts. Birds of prey, for instance, have been on the upswing since the banning of DDT, a pesticide that was found to thin their eggshells.
The report also takes aim at Canada’s Species At Risk Act (SARA), enacted in 2002. The results show at-risk species may have actually declined faster since SARA came into force, though it may take decades before some species show the benefits of the act.
Miller said part of the problem is the time it takes to officially list species at risk and then take steps to protect them. The St. Lawrence beluga, for example, was listed as threatened in 2005, but a recovery strategy wasn’t published until 2012. The whale was upgraded to endangered in 2017.
“There needs to be a sense of urgency,” Miller said.
Still, some scientists argue that the living planet index should be taken with a grain of salt. Stephen Buckland, a statistics professor at the University of St. Andrews in the U.K., said such biodiversity indicators can be misleading.
For one thing, there’s often more research available on at-risk species than on healthy ones, which could mean the living planet index includes a disproportionate amount of data from populations in decline. That could skew the overall results, he said. “You’d expect the biases to reflect more decline than there is.”
Buckland, who published a paper on this issue in the journal Biological Conservation in August, is reluctant to criticize the living planet index too harshly, because it’s undoubtedly true that many vertebrates are dwindling in numbers.
“There’s hard evidence of decline in a number of species for anthropogenic reasons, and the extinction rate is a lot greater now,” Buckland said.
Still, he believes it’s “really pretty impossible to get a scheme that will hold water” for biodiversity monitoring on a large scale, and worries that this index, despite good intentions, is “quite badly biased.”
“I’m not sure it does any favours in the long term,” he said.