How often do researchers check to see whether actions taken to help endangered species work?
Despite many years and millions of dollars invested, research tracking the outcome of conservation action taken to protect or help recover endangered species is often lacking.
“There was far less research than we were hoping for,” said Allison Binley, a postdoctoral researcher at Cornell University’s Lab of Ornithology.
Many species at risk continue to decline in the U.S. and Canada despite years of efforts to reverse negative trends and improve habitats. At least part of this can be blamed on a lack of knowledge—scientists don’t always know all the factors causing species decline. In many cases, wildlife professionals do what they think is best for species without having any real data to back up their plans. Sometimes this is unavoidable—even the experts don’t always know if a plan is going to work beforehand.
But part of the problem with ongoing declines has to do with a failure to track the outcomes of conservation actions—information that could help future efforts. Environment and Climate Change Canada was interested in learning more about how and why researchers studied some conservation outcomes and not others. They commissioned a review study tracking the research on threatened and endangered wildlife listed under Canada’s Species at Risk Act (SARA) from Binley, who was working on her PhD research in conservation biology at Carleton University in Ottawa at the time, and her colleagues.
For the research published recently in Conservation Science and Practice, the team focused on the 209 species listed as endangered under SARA. In 2022, they did a peer-reviewed literature search for studies conducted on those species. They then manually filtered these studies out, looking for those that assessed conservation action or measured the outcome of an action. This usually meant whether the authors of the papers measured a population change or a change in average physical fitness for populations due to the conservation measures.
They only found evidence of this kind of research for 82 of those listed species.
“We found that a lot of the species had very little research available in general—any research, let alone research on conservation outcomes,” Binley said.
Which endangered species are most studied?
Some of the listed species that received little attention were not necessarily a surprise—other research has shown that less charismatic species aren’t a popular in the literature. In Binley’s review, this meant that a lot of listed mollusks, lichens and mosses lacked research on whether conservation action helped the species. Meanwhile, plenty of research was conducted on birds and mammals.
They also found that a small proportion of the overall research for a charismatic species like caribou (Rangifer tarandus) focused on how to conserve and protect them. Most studies focused on aspects like migration, nutrition and other aspects of their physiology and ecology.
The news wasn’t all bad, though. Binley and her team’s review found that protected areas seem to work well for endangered species like the Vancouver Island marmot (Marmota vancouverensis) and the eastern persius duskywing (Erynnis persius persius), both listed as endangered under SARA. They also found that agricultural actions designed to help species, like alternative farming methods or leaving some wild spaces between crops, were often effective, helping species like Henlow’s sparrows (Ammodramus henslowii), listed as endangered under SARA, and vesper sparrows (Pooecetes gramineus affinis), also endangered.
“It was really exciting to see that a lot of agricultural actions that are designed to help species did really well,” Binley said.
Other conservation actions that tended to have more variable effects—sometimes good and sometimes bad—were prescribed burns and alternative timber harvesting treatments. “Prescribed burns are a really important habitat action for some species, but not for others,” Binley said.
Here again, a common problem was a lack of follow-up research, the review found. For example, a lot of studies claimed that prescribed burns restored sagebrush habitat important for greater sage-grouse (Centrocercus urophasianus) and other species, but there wasn’t much follow-up research to see whether this actually happened.
The need for publishing about failures
Binley stressed that it’s not always important just to publish research lauding conservation successes in the long run. “It’s incredibly valuable when a study is published that shows that something didn’t work,” she said. But there is an unfortunate bias against publishing about failures in conservation.
It’s also important to take long-term views on some measures. For example, research revealed that creating better agricultural landscapes for Henslow’s sparrows didn’t work for the first 20 years. But after 30 years, modifications such as allowing more wild space in farms began to show good results.
“It can take decades even to notice that a species is in decline and then decades to fix it,” Binley said.
The review revealed that most studies only lasted an average of three to four years—about the length of your average political cycle or university degree. “There’s not a lot of funding for someone to work on something for 30 years,” she said.
