Who can see in the dark, fly silently, and hear their prey beneath deep snow? Owls!
Owls live on every continent except Antarctica, some in extreme heat, others in extreme cold. How do they thrive in the nighttime world? PBS NATURE explores their special talents on Owl Power, premiering next Wednesday, February 18.
The show explains some amazing facts about owls. Did you know that … Their eyes take up 70% of their skull. Their ear tufts aren’t for hearing, they’re for expressing moods(!). Owls can hear the sound-frequency of a mouse 10 times better than we can. And, to an owl the night is 2.5 times brighter than it is for us.
And there are cool video segments including…
A thermal-sensing camera shows what’s really happening at night!
The barn owl’s slow flight style is compared to a peregrine and a greylag goose.
Great gray owl babies fall branch to branch when they “fledge” from the nest.
Super-sensitive microphones record the sounds of a pigeon, a peregrine and a barn owl in flight. Only the barn owl is completely silent. (Of course, peregrines don’t need to be silent … just very fast!)
Click on the screenshot above for a preview, then watch Owl Power on PBS next Wednesday February 18, 8pm EST/7pm CST. In Pittsburgh it’s on WQED.
In some cultures and for some people, crows have a bad reputation. Their black feathers and eerily intelligent behavior have linked them with bad luck and death. Even those of us who like crows are upset when we see them take birds’ eggs and nestlings. Our distaste for this extends to other members of the corvid family as well.
Some game and conservation organizations kill corvids believing this will help the small birds that corvids prey upon. Does it? A recent study published in Ibis says “No.”
The Institute of Research in Game Resources (IREC) studied 326 interactions between corvids and their prey in Europe and North America. They monitored 67 prey bird species including passerines and game birds.
When researchers removed all predators from the study areas the prey-bird populations increased but when they removed only the corvids there wasn’t much change. In fact, some prey populations suffered in the absence of crows!
Crows had an impact on reproductive success but this didn’t make much difference to the species’ populations. Study author Beatriz Arroyo said: “In 81% of cases studied, corvids did not present a discernible impact on their potential prey. Furthermore, in 6% of cases, some apparently beneficial relationships were even observed.”
So is it good conservation practice to kill corvids? “This method of managing populations is frequently ineffective and unnecessary,” says Arroyo.
Did you know that red-tailed hawks don’t have red tails until they’re more than two years old?
In January Rachel Baer photographed this immature hawk dining at Oakmont’s Riverside Park. You can see that his tail is brown with horizontal stripes. Here’s how you know he’s less than two years old:
Adult red-tailed hawks have rusty red tails (click here to see) but, as Cornell Lab of Ornithology explains, immature birds usually molt into adult plumage — including the red tail — at the beginning of their second year.
During their first winter (age 6 months) and second winter (age 1.5 years) they look like the hawk Rachel photographed.
Here’s the top side of his tail, brown and striped.
And the underside — white (not even faintly rusty) with faint brown stripes.
In the spring of their second year (age 2.0 years) red-tailed hawks begin to replace their brown tail feathers with red ones. That summer their tails show both colors. Click here to see a red-tail with a half-red tail.
By their third winter (age 2.5 years) their red tails advertize their maturity. They’re now full adults and ready to court in the spring.
Of course, there are always exceptions. Cornell’s Birds of North America Online says that 5-10% of immature red-tails can molt into adult basic plumage at age 1.
(*) NOTE: Red-tailed hawks are widespread across North America and the subspecies look different. This blog post describes the eastern subspecies of the red-tailed hawk, Buteo jamaicensis borealis. (The click-through image of a red-tail with a partially red-tail is a dark western bird.)
An immature peregrine falcon banded at Pittsburgh’s Gulf Tower last spring has been hanging out in Wetzel County, West Virginia this winter.
Staff at Wetzel County Emergency Services in New Martinsville wondered about the bands on this “hawk” so they took a picture on January 23 and sent it to the banding lab at Patuxent Wildlife Research Center in Maryland.
Patuxent knew the bands were issued to a peregrine in Pennyslvania so they sent the photo to Art McMorris asking if he recognized them. Indeed, he did.
On icy winter afternoons, just before sunset, intrepid birders gather at Pittsburgh’s Point where the Allegheny and Monongahela Rivers form the Ohio. Dressed in their warmest clothes they stand around on the ice gazing through their scopes and cameras. On January 31, Tim Vechter was among them and took these pictures.
Whatcha lookin’ at?
While the weather is icy, the gulls stay in Pittsburgh.
Each evening the flock starts small. Birders wait and watch as the gulls gather. Among the thousands of ring-billed and hundreds of herring gulls there’s bound to be a couple of rare birds from the Arctic.
That evening Tim photographed two rarities including this glaucous gull identified by his bulky build, white wing tips (herring and ring-billed gulls have black wingtips) and pink legs.
On rare occasions something goes wrong during the first cell division and an individual bird is born a bilateral gynandromorph. In other words, side-to-side (bilaterally) exactly half the body is female (gyn) and the other half male (andro). The dividing line is always vertical from head to tail. To understand how this happens, read this 2010 blog post on bird chromosomes: Anatomy: W and Z
In bird species where males and females look the same it’s hard to tell this has happened but in sexually dimorphic species like the northern cardinal or evening grosbeak, it’s easy to see.
This particular cardinal from Rock Island, Illinois is now famous because he-she was studied extensively by Professor Brian Peer and Robert Motz of Western Illinois University. Their findings — “Observations of a Bilateral Gynandromorph Northern Cardinal (Cardinalis cardinalis)” — were recently published in The Wilson Journal of Ornithology and featured in Science magazine.
One week from today — February 13-16 — the Great Backyard Bird Count will take a real-time snapshot of the birds in North America and beyond.
Since 1998 the Great Backyard Bird Count has enlisted volunteers like us to count the birds we see for four days in mid-February. We count them in our backyards or anywhere we choose. Last year more than 142,000 volunteers tallied birds in 135 countries. Most of us count in North America so the northern cardinal and dark-eyed junco were the #1 and #2 birds. Click here to see which species was #3.
Counting is so easy you can participate from your kitchen window! Just fill your feeders, sit back with a cup of your favorite beverage, and tally the highest count of each species for at least 15 minutes. Then submit your observations online. Don’t be daunted. It’s really easy. Click here for instructions from Cornell Lab.