Winter is here and with it comes excellent opportunities to view an abundance of raptors looking to survive it’s harsh months.
Winter can be a tough time for raptors. With a limited food supply and sometimes frigid temperatures, many first year raptors do not make it through these cold months. Those that do will be well positioned to survive and reproduce for years down the road.
In todays world, a variety of human related factors threaten Golden Eagle (Aquila chrysaetos) populations. Native habitat/prey loss, wind energy development, electrocution, and lead poisoning all pose threats to the Golden Eagle.
This Golden Eagle, in it’s first year of life, will have a difficult time navigating these perils. But these are resilient, long-lived birds. If this eagle can survive it’s first, and most difficult year of life, it stands of good chance of living a long time. Maybe 20 years or more.
Northern Harriers (Circus cyaneus) are amazing raptors. A cross between diurnal raptor and owl (look at that facial disc!), these low-flying birds cruise hillsides, open country, wetlands, and agricultural areas looking for birds and small mammals to pounce on.
Harriers hunt low, facing their head down and listening for the slightest sound that might indicate prey movement. Their owl-like facial disc collects sound and amplifies it, just like a parabolic microphone.
Notoriously difficult to trap, little is known about Northern Harrier migratory and seasonal movements. This hatch-year male was trapped in September at the Goshutes Raptor Migration Site in northeastern Nevada by biologists working for HawkWatch International. A uniquely numbered band was placed on the bird. Hopefully it will be trapped again to help biologist learn more about Northern Harrier migratory movements.
This particular hatch-year Gyrfalcon was trapped less than one-mile from his nest more than a month after fledging. The nest produced a total of 4 fledglings, and his 3 siblings appeared to have wondered further from the nest. Perhaps this little male is having trouble hunting on his own and finding enough food.
Several times this summer we witnessed young Gyrfalcons more than a month out of the nest still following and begging for food from their parents. At what point do the parents stop feeding their own offspring and thus force them to hunt for themselves? I imagine it depends a lot on the individual differences between parents.
I suspect this male was no longer being fed by his parents given his low body weight. Hopefully he’ll quickly learn to no longer depend on his parents for food and become the formidable hunter he was born to be.
These roughly 30-day old Rough-legged Hawk nestlings stand stoically in the stick nest constructed by their dutiful parents. They would be due to fledge from this cliff around 36 to 45 days of age.
I observed this particular nest from a distance some two weeks earlier. At that time the nestlings were a good deal smaller and still mostly covered in downy white. The adult female stood guard over her nestlings almost the entire time while the male was out tirelessly hunting for prey. Almost on cue, once an hour, the male would fly in with a prey item clenched between his small talons.
The male would often deliver the prey item directly to the nest, and then almost immediately leave to begin hunting again to feed his hungry nestlings. The female would then takeover, breaking up the meal into smaller digestible pieces to be fed directly to the young ones. The whole process would take only 1-2 minutes. It appeared that most prey items were small mammals such as voles.
Presently there will be juvenile Rough-legged Hawks abound, testing their new-found ability to fly over the Seward Peninsula of northwest Alaska. Soon after they must venture into new territory as they begin their first southward migration to the lower 48.
Another month, another raptor: the Peregrine Falcon, Falco peregrinus.
We’ve been learning a lot about Gyrfalcons recently because of my work with the Gyrfalcon Conservation Project, but there are many other raptor species on the Seward Peninsula of Alaska. Golden Eagles, Rough-legged Hawks, Northern Harriers, Short-eared Owls, and Peregrine Falcons also call this place their summer home.
Not that long ago, the Peregrine Falcon was listed as an endangered species after populations plummeted from the negative effects of the pesticide DDT. After the banning of DDT, the Peregrine has since been de-listed and can now be found breeding in many major North American cities.
It’s great to find them swooping around their traditional breeding grounds way up north, doing what falcons do.
If you keep up on the Wild Lens blog, this months raptor photograph will come as no surprise: the Gyrfalcon.
For the better part of four weeks I have been studying the worlds largest falcon for The Peregrine Fund and Boise State University’s Gyrfalcon Conservation Project. We now have three nest cameras successfully installed at various Gyrfalcon eyries on the Seward Peninsula in northwest Alaska.
These nest cameras are collecting valuable information on the quantity and diversity of prey adult Gyrfalcon are bringing to their nestlings. This information will help us researchers determine what affects climate change is having on Gyrfalcon diet throughout the breeding season.
All of the previous Raptor of the Month photographs, as well as previous 52-week blog photos can be found at the Wild Lens blog or on Flickr.
Standing a whopping 3-feet in height, the tallest owl in North America inhabits the northern boreal forests and western mountains. Feeding on mainly small mammals, Great-grays are perhaps most famous for a hunting technique termed “snow plunging.”
While the ground of the Wallowa-Whitman National Forest of eastern Oregon was clear of snow, I still had the privilege of watching this Great-gray Owl make several hunting attempts; each time plunging into the grassy meadows of a mature Ponderosa Pine forest.
While I never observed the owl successfully capture it’s prey, it was amazing to watch the bird repeatedly plunge to the ground, seemingly unaware of my existence.
Adult Ferruginous Hawk. Photograph by Neil Paprocki.
While I was hoping to highlight a different raptor species every month for this ‘raptor photograph of the month’ 2014 project, this Ferruginous Hawk was just too cool to pass up (and quite honestly I didn’t have anything better to replace it).
I had the chance to briefly return to central Utah at the beginning of March. I made a quick stop by my favorite Buteo location where I photographed January’s Ferruginous Hawk and was not disappointed. The Rough-legged Hawks were now mostly gone and the agricultural fields consisted of mainly Red-tails and Ferruginous Hawks, although a few Bald Eagles could be seen in the distance.
Someday I hope to capture this species with a more interesting background than just a plain blue sky. And I promise next month will feature something besides a Ferruginous or Rough-legged Hawk. Until then, enjoy all those birds that are passing through on migration or returning to their breeding grounds. April is one of the best months to go birding.
Rough-legged Hawk portrait. Photograph by Neil Paprocki
Our raptor for February 2014 is the Rough-legged Hawk. This time of year always makes me a bit sad as I know the Roughies are making their way poleward, back to their arctic breeding grounds. While some birds will stay on their wintering grounds into April, we won’t see most of these birds again until October or November of 2014.
This adult male was captured and banded using a mouse-baited bal-chatri trap on February 17. In addition to banding this bird, several morphometric measurements were taken to help scientists better understand the differences between males and females of the species.
Below are a series of three photos detailing the wing and tail plumage of this ATY (After-third Year) adult male Rough-legged Hawk.