The Raptor Center

What better partnership than between birds and trees? On May 29, a crew from Mississippi Park Connection planted gravel beds of young trees in TRC’s ambassador bird courtyard. TRC is one of about a dozen partners in a project to establish community tree nurseries for saplings to be transplanted in the fall along the Mississippi River, an important flyway for raptors and other birds.

These gravel beds are a project from Plant for the Future, which aims to address the loss of tree canopy along the Mississippi. Diversifying the canopy will increase resilience to climate change and reduce our urban forests’ vulnerability to invasive pests and insect threats. The gravel beds in TRC’s courtyard include Pin Oak, American Hazelnut, Shagbark Hickory, Black Cherry, and Black Walnut trees.

Why gravel beds? Newly planted trees often struggle to survive because their small root systems are unable to supply enough water and nutrients. According to Park Connection, using a gravel bed drastically increases the survival rate of young trees because they are able to develop a larger and heartier root stock, which helps in reducing transplant shock at the time of planting.

These photos show Park Connection staff planting the gravel bed, with peregrine falcon Palisade and barred owl Florida looking on.

Other sites hosting community gravel tree nurseries this summer include the Science Museum of Minnesota and Surly Brewing. We’re pleased to be part of this partnership! For more information on the community nurseries, check out

As warm weather and longer days return to Minnesota, so do the migrating species of birds, returning from their southern wintering grounds. Of raptor species, the broad-winged hawk (BWHA) and osprey (OSPR) travel particularly far, flying 4-7K miles from Central and South America. Now that they’re back, TRC’s raptor hospital is again seeing patients from those species. As of May 31, the hospital had admitted 5 OSPR since April 18 and 9 BWHA since April 25.

It’s particularly gratifying to see the return of the osprey each spring because a few decades ago, they were highly endangered due to habitat loss, DDT, and human interference. Here in the Twin Cities metro area, the Rivers Park District began a program in 1984 to restore the population. https://www.threeriversparks.org/blog/osprey-reintroduction-great-success-story Now the osprey are a familiar sight, nesting on human-made platforms, ball field lights, and other high places, preferably near water, since they feed almost exclusively on fish.

Each April, the University of Minnesota’s Landscape Arboretum switches on its live Osprey Cam, https://arb.umn.edu/osprey-cam, which allows people to view a nesting pair.

These photos show a current OSPR patient in TRC's hospital, a BWHA patient in an outdoor flight session in preparation for its imminent release, and a close-up of a BWHA.

It’s another foster success story!

When our specially trained baby volunteers go out to rescue a young raptor in need, they scout the scene to look for a viable nest, siblings, and parents. The goal is always to return the young bird to its home nest after being released from care. If the baby can’t be returned to its original nest because it was destroyed and no parents are present, we look for an appropriate foster nest that has young raptors of a similar age.

On May 12, an older nestling barred owl (BDOW), patient 26-0268, arrived from Blue Earth, MN, with minor wing swelling and a bit skinny, but otherwise healthy. No nest or parent owls were located, so this bird was in need of a foster family.

Two days later, another BDOW nestling of similar age arrived from a north suburb of the Twin Cities with minor wing bruising and swelling, similar to owlet 26-0268. In this case, our baby volunteer located a nest with parents and a sibling.

After a short stay in the clinic, we were able to reunite this young BDOW, patient 26-0272, with its family. On May 21, patient 26-0268 successfully joined the family as a foster.

These photos show the two young BDOWs upon admission to TRC’s raptor hospital. Today the two step-siblings are doing well together at -0272’s home nest!

Thanks to supporters such as Xcel Energy Minnesota , our team continues to support the rescue, care, feeding, and renesting of young raptors in need around the state during baby season.

Pictured here is baby great horned owl (GHOW) patient 26-0216, 3-4 weeks old, brought to TRC’s raptor hospital in late April after falling from a nest that had disintegrated. Our specially trained baby volunteers were observing and playing owl calls in the area, but ultimately, no siblings or adults were seen at the site. Thankfully, this young GHOW was successfully fostered with another owl parent and sibling. The second photo shows our former GHOW patient with its new step-sibling a few days later.

Early last week, TRC received a call letting us know about a baby northern saw-whet owl (NSWO) in Sherburne County, MN, that had fallen from a tree cut down the night before. Not long after, a caller in western Minnesota reported finding two owl chicks after cutting down a cottonwood tree. These two reported cases serve as reminders to wait whenever possible till after nesting season to prune or remove trees, even dead ones, which can house cavity-nesting owls and woodpeckers.

The NSWO nestling was brought to TRC’s raptor hospital, where an examination showed irritation from caked mud on the chick’s body and feet. This baby’s siblings did not survive, but after getting a bath and a couple of days in care, this chick was medically cleared. The chick, which was of branching age, was taken back and reunited with its parents.

Nesting season generally lasts from February to August, so it’s best to remove or prune trees in late fall and early winter. If work cannot wait, be sure to inspect the tree for nests, and consider consulting an arborist for expert advice.

A variety of resources are available to help homeowners care for their trees in ways that protect wildlife, and to locate arborists.

Tree Care Resources
https://mntca.umn.edu/resources

Find a UMN Tree Care Advisor
https://mntca.umn.edu/find-tca

DNR Tree Care
https://www.dnr.state.mn.us/treecare/index.html

UMN Extension: How to Hire a Tree Care Professional
https://extension.umn.edu/planting-and-growing-guides/how-hire-tree-care-professional

(Photo of saw-whet owlet by cut-down tree courtesy of Jason Freichels)

TRC recently reached an important milestone in our efforts to monitor highly pathogenic avian influenza virus (HPAI) in raptors. Our hospital has tested over 5,000 individual raptors for active infection with HPAI.

The HPAI virus arrived in Minnesota in March 2022, and TRC quickly swung into action, changing daily operations to develop quarantine protocols and take a leading role in testing for the virus. TRC medical director Dr. Dana said, “By testing every single raptor that comes to our hospital for avian influenza, we are not only keeping our hospital functioning safely, we are contributing to disease monitoring for the region, and our testing can serve as an ‘early warning system’ that protects both Minnesota’s wildlife and its agricultural economy.”

She further explained, “We’ve mapped seasonal trends, identifying that the risk to Minnesota raptors—and farms—spikes from fall through early spring. In the fall of 2025, we detected the virus in a Bald Eagle 10 days before it appeared in a commercial poultry flock. This vital lead time allows farmers to tighten biosecurity and protect their livelihoods.”

Since the start of the outbreak in March of 2022, all new patients are admitted and housed in a biosecure quarantine space until they test negative for the disease. Staff wear full personal protective equipment while working in the space, including Tyvek, fitted respirators, shoe covers, hair covers, gloves, and eye protection.

Funding for the HPAI monitoring project was provided by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources (LCCMR).

Our disease surveillance data is available publicly on our website and updated on a routine basis, so it is accessible to everyone.

https://raptor.umn.edu/about-us/our-research/HPAI

Once a baby raptor is treated at TRC’s hospital and medically cleared for release, we aim to reunite them ASAP with their families in their home nests. Unfortunately, this isn’t always possible. So TRC staff and volunteers are always keeping an eye out for other nests that may provide successful fostering opportunities.

If a baby needs to remain in care at our raptor hospital beyond 48 hours and there is no sibling left “holding” the home nest, the parents may abandon it. But all is not lost! Young raptors can also be placed into foster families that already have a chick of about the same age. The adult owls will care for it as one of their own.

On March 23, we admitted a sibling pair of 4-5 week-old great horned owls from Northern Iowa. Their nest had blown down in a storm, and no foster nests were available locally. The babies were found to be healthy, although one had unusually dark brown eyes instead of yellow eyes. Dr. Dana explained, “The bird never had any inflammation or discomfort or signs of visual compromise. It may have been a genetic difference or perhaps some trauma that was mostly resolved by the time the chick came to us.”

On April 15, after their few weeks in care at TRC’s raptor hospital, a site was found where both siblings could be fostered together, and this pair of owl babies from Iowa got their second chance at life in a nest in Minnesota.

These photos show the great horned owl siblings upon admission to our hospital, comparing their eye color, and the two chicks perched together while in our care.

The great horned owl, though a formidable raptor, is not a nest-builder. So TRC often provides owl parents with artificial nests when we return their young from a medical stay with us.

When nesting season begins, prospective owl parents seek out old abandoned nests built by other species like hawks, crows, and squirrels. These nests might be sufficient to hold a female owl as she quietly incubates her eggs, but not chicks once they become active and start moving about. In addition, spring rains fall, winds blow, and these old nests often break down, resulting in babies falling to the ground. It’s a big reason so many young great horned owls arrive at TRC’s raptor hospital every spring.

When brought into our raptor hospital, the owlets get a complete physical exam, and if medically cleared by our veterinary staff, are reunited with their parents as soon as possible. Keeping raptor families together is the goal!

If the original nest is intact, that’s where we place the baby. But safely returning these chicks may require adding an artificial nest to the home tree. TRC has plenty of these at the ready thanks to the hard work of our volunteers, who come together each winter for a nest-building party in advance of the spring baby season. Using a wire basket as a base structure, the volunteers weave in sticks and branches to make the artificial nest as natural-looking as possible. Later, the nest is completed by adding natural materials such as leaves, pine needles, and any nesting material found on the ground on site.

When artificial nests are needed, they are placed where parents have easy access to resume care, and the youngsters are protected from the elements. The new nest is supported by existing branches and the tree and wired in for stability. Sometimes this requires calling on TRC’s intrepid volunteer arborists who climb great heights to attach nests to trees and carefully place the chick in the new nest.

In these photos, you can see the whole process, from the nest-making party to the successful renesting of some owl chicks! (Nest photos courtesy of Colin Jones)