Climate change is an absolute threat to many wildlife species, but the full picture is more nuanced than previously understood, a new study found.
The study published this month in Nature shows that conservation efforts over the last five decades have not been in vain.
The research team developed a statistical model that analyzed data from more than 14,000 vertebrae populations in the Living Planet Database, according to an SFU news release on the study.
"They found that extreme declines in a minority of populations were driving down the trend statistics, while most species’ populations were generally stable."
Dan Greenberg, an SFU postdoctoral researcher who worked on the study as a PhD student, is among the contributors to the McGill University-led research.
The study by Jennifer Thuncher on Scribd
He said when they looked at the data more closely, some short analyses of species were impacting the overall outlook.
"Previous analyses have estimated a mean vertebrate decline of more than 50% since 1970," reads the study. "We show, however, that this estimate is driven by less than 3% of vertebrate populations; if these extremely declining populations are excluded, the global trend switches to an increase."
What this means is that things are still declining but for every decline, something else seems to be doing alright.
"It seems that things are changing, but we don't really have a good grasp on how or why they are changing," he said.
"There are regions where there are just general declines — where the overall signature does suggest that species are declining. We did find those. We found that in things like birds in the Indo-pacific realm; reptiles in Europe and Asia, but for most regions of the world and most groups, it seems that about as many species and populations that were declining, there was about as many that were increasing or stable."
Some species, like coyotes, do well around humans, Greenberg said. Others are not doing well at all, and we are in danger of losing them.
In B.C, vertebrate species that appear to be suffering declines include: white sturgeon, northern leopard frog, Oregon spotted frog, woodland caribou, fisher, western painted turtle, various populations of steelhead, the Rufous hummingbird and the barn swallow.
Asked if he is worried this study will be used to disregard climate change impacts, Greenberg said he hopes that is not how the data is interpreted.
"The very simple way of looking at it is that things are fine if everything balanced, but of course what I want to emphasize... that still means we are poised to lose species and we are poised to lose population," he said, adding we don't really have the full picture yet.
Greenberg said more data on species is needed to understand fully what is happening, and what kind of world future generations are going to inherit.
"We might not just want a world that is filled with rats and raccoons. But a bit little more diversity in the sort of species we encounter and the ecosystems that we like to go out and play in," he said.
People would be surprised to learn that even in Canada, we don't have a lot of data on some species.
"At best, we often maybe have one or maybe three populations [of a species] we have studied, but for most species, we have no populations we have data for," he said. "Even here in an economically advanced country, we still have a pretty coarse grasp on how things are changing."
He said that new citizen science initiatives like iNaturalist and eBird can play a role in filling the gaps in data where scientists don’t have the capacity to do the research.
Find out more about B.C.'s species here.
