Each year, tens of thousands of animals across Minnesota find themselves in the compassionate care of wildlife rehabilitators, brought to rescue centers because of injuries, illness, or human-related conflicts. 

The Raptor Center (TRC) at the University of Minnesota College of Veterinary Medicine (CVM) plays a critical role in this effort, admitting over 1,000 birds annually. As a leader in avian rehabilitation, research, and education, TRC not only provides lifesaving care but also advances the understanding and conservation of raptors, setting a gold standard for wildlife rehabilitation.

So when the Migratory Bird Division of the US Fish and Wildlife Service (USFWS) was looking for information about the contributions of rehabilitation to conservation, TRC was an obvious partner.

Dr. Juli Ponder, CVM professor and former director of TRC, is very familiar with the field’s unknowns. 

“We’re so data deficient when it comes to understanding the outcomes of wildlife rehabilitation,” she says. And while many consider the effort to save an individual wild creature as an end in itself, understanding if and how rehabilitation contributes to overall species preservation and ecosystem health is crucial when it comes to allocating scarce conservation resources.

The USFWS reached out to Ponder to commission a report that would identify knowledge gaps and potential tools for improved data collection on the impact of avian wildlife rehabilitation. She worked with Dr. Michelle Willette, fellow CVM professor and senior veterinarian at TRC, along with CVM veterinary public health and preventive medicine (VPHPM) residents Drs. Janice Mladonicky and Margaret Sirolli, to develop the report.

“We needed to take a systematic look at what the existing research tells us in order to know where to go from here,” Ponder says.

Flying blind

Ponder, Willette, and their team conducted a comprehensive assessment of the published research on post-release outcomes of rehabilitated avian wildlife. They wanted to understand the direct impacts of wildlife rehabilitation and also to address its indirect contributions to overall conservation efforts.

What stood out the most was the need for more and better information. 

The work to track and understand outcomes is resource-intensive, and wildlife rehabilitation efforts, generally volunteer- and donor-driven, often operate on a shoestring budget.

Given these financial realities, the team was not surprised to find that the majority of existing research evaluated animals’ post-release survival following an oil spill. The Oil Pollution Act of 1990—passed after the infamous Exxon Valdez tanker spilled almost 11 million gallons of crude oil into Alaska’s Prince William Sound—created the legal framework requiring polluters to assess their environmental impact. The mandate for post-spill research (funded by those responsible) means that it has outsized representation in wildlife rehabilitation research generally.

In addition, the team found a lack of consensus about how “success” is defined when it comes to rehabilitation outcomes. Most of the published research did not specify a definition of success. Among those that did, some consider survival of the released animals (defined using varying time frames) as the key metric to success, while others focus on the released animals’ contribution to species reproduction as the primary metric.

Despite these gaps, a number of studies documented benefits in terms of post-release survival (with significant species variation), along with many indirect benefits. These indirect impacts include ecosystem monitoring; contributions to knowledge bases of biology, ecology, veterinary medicine, and disease; and public health and education. 

“These indirect benefits—to animals, people, and the environment—demonstrate the interconnectedness of the health and welfare across species,” Willette says.

Charting a path forward

Among the team’s recommendations, standardization of terminology and data collection represent the greatest needs—reflecting the decentralized nature of the systems in place.

Wildlife rehabilitation services in the U.S. are something of an improvised tapestry, consisting of a patchwork of efforts among government agencies, nonprofits, and passionate volunteers with the aim of caring for orphaned, sick, and injured wild animals to release them back into the wild. 

One of the challenges in creating a comprehensive picture of the contributions of wildlife rehabilitation is that it is regulated primarily at both the federal and state levels, so processes for permitting and reporting vary widely across the country.

“With the number of animals going through wildlife rehab centers each year, these reports have the potential to offer us a rich source of data,” Ponder says, adding the reports currently can’t be utilized because of the lack of standardization. “If we can integrate data across centers, we would have a wealth of information we don’t have.”

That data could not only offer a broader sense of the impact of wildlife rehabilitation, but it could also provide a source for information about ecological red flags with widespread impacts that might not otherwise be detected.

Willette sees significant potential for how wildlife rehabilitation can help to advance other areas as well: “As wildlife rehabilitation science continues to advance, the sector is increasingly collaborating with wildlife managers and scientific institutions to decrease human-wildlife conflict, advance wildlife and medicine studies, inform public policy, and complement ongoing wildlife conservation efforts.”

Find the team’s full report on the USFWS website, and learn more about The Raptor Center here.