Minnesota EagleCam Update

minnesota department of natural resources

EagleCam Update


 January 29, 2018


Courtship behaviors

We have exciting updates on the new EagleCam.  If you’ve checked in lately you’ve noticed a bit of housekeeping activity as the eagles organize their nest, adding sticks and arranging them as part of their breeding ritual. Nest building occurs prior to mating, usually beginning one to three months beforehand. Photographers in the area have captured some dramatic courtship displays, including some entertaining and breathtaking swoops, cartwheels and stick exchanges in mid-air. Eagles do not mate in the air, contrary to popular belief, but we caught a rare sight at the nest last week.  Check our Facebook page for video of the pair mating in the nest! They will mate several times a day, on nearby branches or in the nest.  This means that egg laying could begin in as little as 10 days.

A coveted nest

This weekend, and over the past few weeks, there have been a variety of bald eagle visitors to the nest, and many people have expressed concerns that the resident male has vanished.  We believe the male is fiercely defending his territory, keeping him too busy to visit the nest itself.  He has been seen in the area, and we also believe he is still the mate. The visitors have ranged in age  from one-year-old juveniles to adults, attempting to claim the nest, the female or both.  The resident female is fiercely defending her nest, and she makes it very clear that her male is the only male she will tolerate. 

Night visitors

The infrared imaging feature on the new camera has proven to be very informative.  White-footed mice and raccoons are regular nighttime visitors.  Our scientists believe the mice also use the eagles’ nest for their nests!  They feed on the “nestovers” from the eagles and use the feathers and fur for making their little homes within the large eagle nest. The raccoons also have been cleaning up the leftover food, but they’ve been warned by the eagles that their visits will soon need to end. 

Webcam issues

Poor quality streaming from the webcam has been frustrating for viewers and cam operators as well.  We are working hard on these issues and have ruled out a number of factors. The camera itself is running fine. We have no doubt that the pixilation is happening somewhere else, but we can’t pinpoint it yet. The microphone placed in the nest is not working. It’s not part of, nor attached to, the camera.  The mic will be replaced, but not until the chicks are banded.  Xcel Energy generously provides the bucket truck to get us to the nest, and we reserve these favors for necessity.  They have one truck for this region that reaches high enough for camera access, and demand for this truck is high.  We ask that you remain patient while we work out the bugs of this brand-new system.

Winter adaptation

Many birds and other animals have a variety of physical and behavioral adaptations and strategies that allow them to survive even the coldest weather. Here’s a look at ways these amazing birds survive and keep us entertained throughout the long winter months.

Birds have a higher metabolism rate and thus, a higher body temperature than humans, making it a challenge to maintain this body heat in the winter. Many birds will spend the fall taking advantage of abundant food sources to fatten up for winter -- something we humans try to avoid.

Feathers are excellent insulators and many grow extra feathers during a fall molt, adding about 20 percent to their weight in winter. Their feet are covered with specialized scales that minimize heat loss and they can constrict the blood flow to their legs and feet so blood flows only to their major organs. This means less energy is required to circulate blood and less warmth is lost.

Yes, birds do shiver, especially in extreme conditions. Shivering is a short-term strategy that raises their metabolic rate so they can generate more body heat. Shutting the heat down is also an important strategy. Birds can turn their legs into heat exchange stations, a term called “countercurrent heat exchange.” Because the veins and arteries in their feet and legs are located near each other, the warm blood leaving their body is cooled before it reaches the extremity (like a foot). Similarly, cool blood is warmed before entering the body. By cooling the blood before it reaches the foot, they do not lose as much heat (less energy loss). By warming the blood before it enters the body, they are less likely to get chilled by the cold blood.

Behaviorally, birds use a variety of techniques to conserve body heat.

  • Fluffing out their feathers to create pockets of air for additional insulation.
  • Tucking their beaks into their feathery shoulders to breathe in the warm air of their body.
  • Crouching to cover both legs with their wings feathers to shield them from the wind and cold.
  • Turning their backs to the sun to take advantage of solar heating on a sunny day.
  • Roosting together in shrubs or empty bird houses to conserve much needed heat.

Many birds will go into “torpor” to conserve energy. When an animal is in a state of torpor, its body temperature is lowered and its heart, metabolic and respiration rates are slowed to conserve energy and calorie output. It’s a short-term strategy (a few hours or overnight) for surviving frigid temperatures and severe storms.

But how can a bird successfully hatch its eggs in the dead of winter?

A few birds, such as the bald eagle and great horned owl, rely heavily on a brood patch, a bare spot on the belly that facilitates heat transfer to the egg during incubation. Interestingly, both male and female bald eagles develop a brood patch and share in the incubation duties. This is not true of the great horned owl.

Get warm and feathery

EagleCam viewers can rest assured that the bald eagles are well equipped to raise their young in the frigid Minnesota winters. Anyone can help other birds and nongame wildlife stay warm in winter by donating to the Nongame Wildlife Program tax checkoff. Just look for the “loon line” on Minnesota income tax and state property tax forms and give a gift to help continue efforts to provide quality habitat for all endangered, threatened and nongame species. It may just help warm your winter!

Minnesota Nongame Wildlife Program 

The  EagleCam and associated technology are paid for and maintained by the DNR’s Nongame Wildlife Program, which is largely supported by voluntary contributions.  Recognized as one of the most successful programs of its kind in the United States, the Nongame Wildlife program helps hundreds of Minnesota species through habitat restorations, surveys and monitoring, technical guidance, and outreach and education  – critters such as bees, butterflies, songbirds, loons, frogs, turtles and bats, as well as eagles. Donations to the Nongame Wildlife Program are matched dollar for dollar by the Reinvest in Minnesota (RIM) license plate fund. They’re also tax-deductible.  Learn more at http://www.dnr.state.mn.us/eco/nongame/index.html.