University of Montana graduate student Mary Venegas is leading research to assess the lingering effects of historic mining on songbird populations near Anaconda, Montana. The project focuses on how heavy metal contamination from past smelter operations may still be affecting wildlife in the area.
Venegas, who grew up in Venezuela and later studied at UM’s Wildlife Biology program, works with nestling songbirds to determine if restoration efforts have been effective. “One of the great things about studying baby songbirds is that at this age their nervous system hasn’t developed yet,” Venegas said. “They don’t have the instinct to be afraid, so they’re easier and safer to handle than adult birds.”
Her research takes place in gulches surrounding Mount Haggin, where remediation is challenging due to steep terrain. While significant restoration has occurred in residential areas since the Environmental Protection Agency designated Anaconda a Superfund site in 1983, remote landscapes remain harder to treat. Erosion control measures such as planting vegetation and installing man-made structures have been implemented to reduce soil loss and prevent contaminants from spreading into waterways.
“These gulches should be covered in lodgepole pine,” Venegas said. “But we had to build mine shafts and houses for miners. So we were logging everything.”
Venegas collects blood and fecal samples from nestling birds across sites with varying levels of contamination. These samples are analyzed for heavy metals and dietary content, helping researchers understand whether local food sources contribute to contamination found in the birds.
“Baby birds are what we call ‘locally grown,’” she explained. “The adult bird is not going to go further than a few hundred meters to forage for food, so the nestlings are getting fed from their immediate surroundings. So when we find heavy metal contaminants in the babies, we know those came directly from the bugs which came directly from the soil of this area.”
She emphasized that handling young birds does not cause parents to abandon nests: “One myth I’ll bust right now is that you will not keep a parent bird from its nest if you touch a nestling,” Venegas said. “Parents will consistently go back to the nest after we’ve handled the nestlings. The issue with handling is scent trails, so you don’t want to handle them too long or often and leave a scent that predators could follow. But the parents will never give up on their babies.”
Venegas’s work is funded by the Natural Resource Damage Program alongside Montana Fish, Wildlife and Parks (FWP). It aims not only to gauge current impacts but also inform future land management decisions.
“The hard part is just balancing how to get enough data while keeping birds safe” she said. “But it’s never an option for them not to be safe.”
According to Venegas, birds serve as ecological indicators due to their abundance and position within food chains: “Birds are great ecological indicators,” she said. “Their abundance means you can go anywhere and see birds. You can have multiple species that tell you different stories depending on their behaviors or diets. They’re in a good position in the food chain that gives you an idea of what’s happening at the levels below them. And they’re cute – that’s another good reason to study them.”
The findings will help agencies like NRDP and FWP evaluate whether decades of remediation have succeeded or need adjustment: “One of my hopes for this project is that it will help inform restoration efforts in this watershed and other watersheds,” Venegas said. “Maybe we need to revisit the plan for the area around Mount Haggin or simply apply this knowledge to other systems.”
“This project is not just about the wildlife we’re targeting,” she added. “It’s about the impacts of mining and metal contaminants, which affect all parts of the food chain, including us.”
Her research forms part of broader efforts by UM’s Bird Ecology Lab (UMBEL) investigating terrestrial impacts from mining—an area less studied compared with waterway-focused research.
“Mining is an ever-present activity of humans,” Venegas said. “We mine a lot and we will continue to do so, so understanding the impacts of those activities is super important for understanding our past, present and future.”
