Nutrition’s fundamental role in raptor rehabilitation
About 1,000 sick and injured raptors pass through The Raptor Center’s clinic every year. For each of these patients, proper nutrition is a cornerstone of healing and rehabilitation. It is also intensely personal.
“Diets are tailored to the individual and its nutritional health,” explains Lori Arent, MS, assistant director at TRC. Clinicians assess new patients thoroughly, using stats like weight, hydration status, and gastrointestinal tract (GIT) function to build a nutritional plan. Some admittees are a healthy weight. Others are starving.
“There’s definitely some general protocols that we follow, so it’s not like creating the wheel every time.” Pellet egestion, for instance, influences every raptor’s diet. This process takes place inside the gizzard. It grinds indigestible matter into a compact pellet that is then regurgitated.
Egestion is energy-intensive, and some patients need to devote most of their energy to healing. “If a bird comes in and it’s really, really thin, that’s when we’ll start with the liquid diet,” says Arent. “We start very slowly to get their system moving and provide them with some energy so that they can then form those pellets.”
Gavaging, or “tube feeding,” is crucial for severely dehydrated raptors and those with beak or mandible damage. Staff administer the nutrient-rich formula via a lubricated tube, which passes down the esophagus and directly to the stomach.
Soon, patients graduate to clean meat: breast meat, liver, and organs. This mixture is free of fur, feathers, and bone, making it easy to digest. Those who respond well move on to skinned meat. The gradual reintroduction of bone helps staff gently gauge patient GIT function.
“We try to get them onto whole food as soon as we can,” Arent says, “because that’s really where they will gain weight.” But proceeding to whole food too quickly can overload the system. Staff look out for excessive weight gain and problematic behavior, like food begging in hungry young raptors. “If the bird isn’t responding well or processing the type of nutrition we’re giving him, we recognize that pretty quickly.”
What’s on the menu?
Both TRC’s patients and resident educational ambassadors receive items that reflect their natural diet. This includes a wide variety of responsibly sourced poultry, rodents, and fish.
That fish? Locally caught. “We have a handful of people that we know and trust,” Arent explains. These donors deliver fresh sunfish, bluegills, and other panfish to the Center. A special permit allows TRC’s freezers to exceed more than the legal fishing limit, allowing for multiple same-day drop-offs.
Some donations, like wild game, are off limits. Lead poisoning and bacterial contamination are just too risky. “The birds in our care are already suffering from some type of ailment, and they have added stress in their systems,” explains Arent.
Instead, TRC sources poultry and rodents from dedicated, quality-assured breeding operations. Bird-eaters dine on quail from “down in Owatonna” and “day-old chicks from a hatchery in Iowa.” Sometimes adult poultry comes right from the University of Minnesota campus, courtesy of the Department of Animal Science and its Poultry Teaching and Research facility. Rodent-eaters enjoy rats and mice provided by RodentPro in Indiana.
Occasionally, circumstances require live feeding: when testing a patient’s vision and foot function, for instance. But live prey is mostly reserved for birds that have never hunted before.
TRC treats around 120 young raptors each year. A handful of them, Arent says, “are starving for no physical reason.” These raptors were likely separated from their parents too early. They’re in a crucial formative period—a strong drive to always search for prey will be necessary for their survival. “It’s tough being a young raptor.”
Between 60 and 70 percent of young raptors don’t survive their first year, largely because they fail to thrive after leaving the nest. TRC staff can’t teach them all the basics. “But what we can do,” explains Arent, “is make sure that when they see something appropriate, they go after it quickly.”
At mealtime, staff place a black pan containing one or two mice in the enclosure. The raptor has 10 minutes at most before the pan’s removed.
“We want those birds to be quick,” Arent says. “Our belief is you really want to give them short windows of opportunity, which is what they’ll be faced with in the wild.”
Compliments to the chefs!
There is no one “master chef” running TRC’s kitchen. “It’s a team effort,” says Arent. Each patient under active medical care is assigned to a clinician responsible for its diet. Upon transitioning to rehabilitative care, a new clinician takes over. Volunteers help prep food and provide medications.
Meals are an important vehicle for medication and nutritional supplements, most of which come in flavorless powder form. “Raptors really don’t have a good sense of taste anyway,” says Arent. “We put medications in gel caps so the bird gets the full dose and just sprinkle special raptor vitamins on their food every other day.”
Juicy meat is great for hiding pills—rat belly is a favorite— but wiser birds force staff to get creative. One method involves hand-feeding the concealed pill in between bites of something extra irresistible, like liver.
Clinicians use creative problem-solving at every stage of a patient’s journey. In rehab, for example, multiple birds of the same species are often housed together. This can make mealtime challenging among more aggressive raptors. Arent cites red-tailed hawks as an example. “Every now and then, we’ll get a bird who is just so food aggressive that we have to house it separately.”
Housing arrangements can grow complicated. Depending on the season, TRC may have anywhere from 40 to 100 birds at any given time. “It’s staggering how much money we pay to feed not just our rehab birds but the education collection as well,” Arent says. “TRC spends about $35,000 on food every year. It is a basic need.”
There are a lot of beaks to feed—and TRC is hungry to help.