Brazil is one of the most biodiverse countries in the world, but the nation’s wild animals are under heavy pressure from human activities. In this study, researchers examined more than a decade of records from a large wild animal rehabilitation center in southeastern Brazil. They wanted to know what types of animals were being brought in, when, and why, and what happened to them in the end. They analyzed birds and mammals separately and grouped them into broad types, such as songbirds, raptors, rodents, and primates. For each group, the researchers looked at:

• The main reasons for admission;
• Admission patterns across the seasons;
• Final outcomes; and
• Links between reasons for admission and final outcomes.

Trends And Outcomes For Birds

Between 2012 and 2023, the center admitted 23,441 birds representing 329 species. Most were songbirds (82%), followed by raptors (12%), waterfowl (3%), landfowl (2%), and shorebirds (1%). There was a trend towards increasing admissions over the years.

The reason for admission was known for about 87% of cases. The top causes were wildlife trafficking (43%) and “requested removals” (41%), where members of the public asked authorities to remove the birds from human spaces. Other common reasons for admission included being hit by vehicles, dog and cat attacks, and injuries from kite strings.

These issues were seasonal, with some being more common at certain times of year for certain groups. For example, trafficked songbirds were most often admitted in April, May, July, and November, while requested removals of waterfowl were highest in July. Kite string injuries peaked in March for songbirds and July for raptors.

Overall, outcomes for the birds were poor. Among those with data available, about 63% died, while 20% were released back into the wild. Around 17% ended up in permanent captivity such as zoos or conservation centers because they lacked the skills or were physically incapable of surviving on their own in the wild. Although death was the most common outcome for all bird groups, raptors had a somewhat better chance of release (23%), particularly if their reason for admission was a removal request.

Trends And Outcomes For Mammals

The center admitted 12,395 mammals from 73 species over the same 12-year period. Most were opossums (70%), followed by primates (13%), rodents, rabbits, and hares (8%), carnivores (4.5%), armadillos, sloths, and anteaters (2%), and ungulates (2%). As with birds, mammal admissions went up over time.

The reason for admission was known for about 72% of cases. The top cause was requested removals (49%). Other common reasons for admission included dog attacks, vehicle collisions, injuries of unknown cause, and electrocution from power lines.

Different kinds of mammals faced different threats throughout the year. For instance, opossums were often admitted for dog attacks and requested removals, which were highest in September and October, respectively. Electrocutions peaked for primates between March and June. Vehicle collisions impacted carnivores the most in September and ungulates the most in July.

As with birds, most mammals didn’t survive or return to the wild. Among those with a recorded outcome, about 68% died, 17% were released, and 14% ended up in permanent captivity. Again, while death was the most common outcome for all mammal groups, armadillos, sloths, and anteaters were much more likely to be released (37%), particularly if their reason for admission was a removal request.

Human Causes, Human Solutions

Overall, the study shows that, similar to other countries, human activities are behind most of the reasons wild animals end up in rehabilitation centers in Brazil. They also have a significant impact on whether the rescued animals live, die, or spend the rest of their lives in captivity.

Issues such as requested removals, vehicle collisions, dog attacks, power lines, and kite strings all play a major role in harming Brazil’s wild animals and keeping many from returning to their natural habitats. Thus, the authors highlight the need for more effective preventative measures, including:

• Wildlife crossings, directional fences, and adequate signage to reduce vehicle collisions
• Modifications to cables and poles to minimize the risk of electrocutions
• Prohibiting the use of kite strings coated with sharp materials like glass (a common practice in the popular activity of kite fighting) to lessen injuries
• Stricter laws and penalties to tackle wildlife trafficking

The authors also encourage more effective education aimed at the general public to inform them about the different species of animals found within the country and their natural behaviors. This could help people make more informed decisions on when intervention is necessary, as animals who don’t actually need rescuing can contribute to overcrowded rehabilitation centers. This could also empower them to more closely monitor their dogs and cats to prevent attacks, particularly at times of year when wild animals are most vulnerable. Lastly, the authors suggest improving Brazil’s rehabilitation centers themselves through more specialized training and increased funding.