Some cities have great birds.
Even though New York is the largest city in the U.S. they have a wide variety of habitat and some great places to go birding. I didn’t know about Bayswater until Gintaras Baltusis, a long time follower of this blog, told me about it.
Gintaras was in Queens at Bayswater Park last weekend to photograph airplanes approaching JFK airport. While he was focused on airplanes this osprey came over with a newly caught fish.
Nice!
(photo by Gintaras Baltusis)
Birds love to perch on wires and power poles, the bigger the bird the bigger the wire. Unfortunately this affinity poses a threat to very large birds because their long wings can touch two wires at the same time and electrocute them. Vultures are especially vulnerable because they roost in large gregarious groups. If they jostle their buddies too much … ooops!
Cape vultures (Gyps coprotheres) of southern Africa, like most Gyps species, are declining. They are listed as threatened because of decreased carrion for their chicks, poisoning from medication in livestock carcasses, electrocution and collision with wires, and exploitation for traditional medicine/religion.
Cape vultures live a long time and reproduce slowly so significant losses of any kind pose a problem. There are protected areas in southern Africa where the vultures aren’t exposed to so many threats but there is also a growing power grid.
W. Louis Phipps and his team decided to find out how cape vultures used the power grid so they affixed GPS trackers on nine cape vultures — five adults and four immatures — to see where they would go. The results were somewhat surprising.
The cape vultures’ home range is larger than expected; some traveled more than 600 miles one way. Given the opportunity to travel the power corridors, that’s what they did. Cape vultures are cliff birds so the power towers gave them high perches and clear sight lines in formerly useless habitat. The study also found that the vultures fed more often on private farmland than in protected areas. (The vultures would say, “Well, that’s where the food was.”)
It’s the classic Catch-22. The power corridors have expanded the cape vultures’ range but the wires sometimes kill them. In a declining population it makes a difference.
For more information read the full study here at PLOS One.
(photo from Wikimedia Commons. Click on the image to see the original)
At Hawk Mountain Sanctuary, this fall’s high count of 1,338 broad-winged hawks flew by the watch on September 20. That number sounds large but those hawks join all their cohorts from North America to pass a small strip of land between the mountains and the Gulf of Mexico near Veracruz.
The Veracruz Hawk Watch is called the River of Raptors because more than 100,000 hawks per day may pass through between the September 20 and October 25. During the first two weeks of the watch almost all of them are broad-winged hawks. On September 23 the broad-wing count at River of Raptors in Cardel was 354,091.
Above, a slideshow video from a 2011 birding trip to Veracruz celebrates the hawk migration and shows the birds and scenery in the area. (Sorry about the ads.)
Below, a very short video shows the “river of raptors.” A huge kettle of hawks circles up, then tails off in a broad river to the left, heading south. The Spanish title of this video “Vortex Cambiando a Una Linea Ancha” means “Vortex Switching to a Wide Line.”
Wish I’d been there…
(videos from YouTube)
Great Gray Owl nest Aitkin Co 640×360 from Sparky Stensaas on Vimeo.
Have you ever seen a great gray owlet?
Most of us haven’t because the bird nests in bogs in the remote north woods.
Last summer photonaturalist Sparky Stensaas jumped at the chance to film a family of great gray owls at their nest in Aitkin County, Minnesota.
His video captured the owlets when they were just ready to leave the nest. They’re fluffy and almost cute — except they have to grow up to match their beaks.
I’m impressed at how wise and old Mother Owl looks as she watches nearby. I am also very impressed by the constant noise and vision of bugs flying close to the camera. Were there mosquitoes in the bog? Need I ask?
Play the imbedded video above or click here to watch the full screen video on Vimeo.
These babies are growing up great.
(video by Sparky Stensaas, thephotonaturalist.com)
p.s. A quiz for those who can bird by ear! Can you identify the bird songs in the background?
July 29, 2013
A troubling plan slipped under the radar of Easterners who care about barred owls and native birds.
In the Pacific Northwest, northern spotted owls have been listed as threatened since 1990 under the Endangered Species Act. The number one cause for their decline is the logging of old-growth forest. The logging stopped in the national forests in 1991 but the spotted owl continues to decline, especially in smaller forest tracts left behind by logging.
Barred owls are distant relatives of the northern spotted owl and formerly lived only east of the Great Plains. In the 100 years barred owls have slowly spread north and west and now inhabit the Pacific Northwest as well.
In recent years biologists studying spotted owls noticed the spotteds declined in zones where barreds increased, so U.S. Fish and Wildlife Service has proposed killing barred owls as an experiment to see if this helps the northern spotted owl.
The proposal, published in March 2012 as a Draft Environmental Impact Statement, included a public comment period. We may not have noticed the proposal but westerners saw and commented.
The comments were overwhelmingly negative from “Don’t do it!” to “This is stupid!” to an excellent letter by biologist Elizabeth Ellis who has studied northern spotted owl populations and pointed out the flaws in the proposal including the lack of barred owl population studies (it is threatened in parts of its range!), unknown human contribution — if any — to the barred owl’s range movement, the fact that the proposal tracts where barred owls have gained a foothold are known to be too small to adequately protect the northern spotted owl, and the wisdom of using limited management funds to kill an unstudied species.
If I’d had a chance to comment I would have said… (stepping up on my soapbox)…
Humans directly caused the disappearance of 90% of the Pacific Northwest old growth forest. When species are going extinct because of our actions we have a choice: Do we cut down the last 10% of the forest or stop logging? We can control the things that humans do, however…
We cannot control the rest of Nature. Humans did not actively introduce the barred owl. We don’t fully know why it arrived. It is hubris to think we can control what’s happening by killing it.
The barred owl is so closely related to the northern spotted owl that the two can interbreed. The barred owl may be adding strong genes that the spotted owls need to survive. Interbreeding is anathema to species purists but it’s how nature works. Would we cull blue-winged warblers because they interbreed with and seem to out-compete the less abundant golden-winged warbler? Culling native birds to protect a favorite species is a dangerous precedent.
The Pacific Northwest is not an isolated island so barred owls will continue to naturally arrive in the northern spotted owl’s territory. If the proposed experiment works the culling will have to continue as long as humans have the stomach and the money to do it.
I could go on and on…
At this point it is up to U.S. Fish and Wildlife Service to decide whether to go forward with their plan. I hope they drop it like a hot potato!
(stepping down from my soapbox…)
Thanks for listening.
Click here for information from the U.S. Fish and Wildlife website on their plan to kill 3,600 barred owls in the Pacific Northwest.
(barred owl in Florida, photo by Chuck Tague)
Some raptors have special techniques for finding food. This one has used trains and motorcycles.
Aplomado falcons (Falco femoralis) are native to grassland and marshland from Mexico to South America where they eat birds, insects and small vertebrates. Sometimes they hunt while soaring or from a perch but when hunting birds they prefer to fly fast through thickets to flush them from cover. This technique is similar to a Coopers hawk.
Mated pairs like to hunt cooperatively. The male makes a distinctive “chip” sound to call his mate to a hunt. Sometimes the female will even come off the nest to participate. The male corners the prey by hovering above the thicket. The female flies through and flushes it.
When his mate can’t come out to hunt, what’s a guy to do? Borrow a motorcycle.
Aplomados have figured out that our large, loud vehicles scare small birds into flight. According to Birds of North America online, one researcher reported an aplomado following a motorcycle to pick off small birds flushed from the side of the road. Another reported a falcon flying with a train and switching sides to check out the ditches.
These falcons were extirpated from the U.S. in the 1950’s and only recently made a comeback in New Mexico and south Texas, partly on their own and partly thanks to reintroduction programs.
When I travel southwest to find an aplomado I wonder … will it help to watch for motorcycles?
(photo from Shutterstock.com)
What does this bird …
… have in common with this roller coaster?
The roller coaster was named for him.
The SheiKra roller coaster in Busch Gardens Tampa amusement park dives 200 feet at 70 miles an hour. In the photo above, the sloped run takes the cars up. The dive section is so vertical you could mistake it for a support strut. Yow!
The coaster was named for the shikra (Accipiter badius), a hawk of Asia and Africa, because the hawk will dive vertically to capture prey.
He looks a lot like a Coopers hawk because both are accipters. In fact he’s very similar in lifestyle and size to our sharp-shinned hawk. When they’re upset they nearly sound the same. Here’s the voice of a shikra, and here’s the voice of a sharpie.
I would not know of the shikra’s existence except for a Wikipedia article that featured the roller coaster. When it mentioned a bird I had to look.
I love these connections.
(both photos from Wikimedia Commons. Click on an image to see its original)
Browsing through photos on Wikimedia Commons, this portrait of a falcon caught my eye. He’s one of six species of falcons found in Australia, new to me because he doesn’t occur in North America. The only falcon we all have in common is the peregrine.
The brown falcon (Falco berigora) is slightly smaller than a peregrine and has a different lifestyle. Rather than capture prey in the air he uses a perch-and-pounce method to capture small mammals, lizards and snakes, small birds, and insects. This is similar to the red-tailed hawk’s hunting technique.
Brown falcons don’t need to fly fast. Their wing beats are slow and they glide in a shallow V the way northern harriers do.
Though they share characteristics with hawks, Perth Raptor Care says they have a lot of personality. Click here for a video at Arkive.org that gives you a window on the lives of brown falcons: contending with crows, sharing with a mate, feeding the “kids.”
I love their brown pantaloons.
(photo from Wikimedia Commons. Click on the image to see the original)
.jpg)
Any parent can tell you that raising kids is hard work and even harder if there are multiple infants the same age. (Think triplets!)
Most birds experience this multiple effect every time they nest. In fact, the work is so exhausting that having “extra” kids beyond their normal clutch size decreases the parents’ life expectancy in some species.
This was shown in studies of common kestrels in Europe in the 1980s.
A team led by Cor Dijkstra artificially lowered and raised brood sizes of common kestrels by removing eggs from some nests and adding them to others. Kestrel parents whose brood size of five remained normal or was reduced to three experienced the typical winter mortality of 29%. On the flip side, adults whose broods were augmented were much more likely to die the next winter. 60% of the kestrels who raised two extra chicks were dead by the following March.
For thousands and thousands of years the clutch size of the common kestrel has been honed by the deaths of those who raised too many. The birds settled on the number five. More than that can kill them!
(photo of common kestrel nest in Germany from Wikimedia Commons. Click on the image to see the original.
Today’s Tenth Page is inspired by page 521 of Ornithology by Frank B. Gill.)
So many of us have been watching the bald eagles’ nest in Pittsburgh’s Hays neighborhood that we’ve begun to think of them as “our” eagles.
Last Saturday, June 29, was a big day for the young eaglet. After weeks of flapping she lifted off. Tom Moeller photographed her flying for the very first time.
Above she takes off from the area of the nest. Below she crosses over to fly toward her father’s perch. She is huge!
The entire photo series of her first flight is here on Tom Moeller’s Picasa site.
Do you want to watch Pittsburgh’s eagles on the Fourth of July? Join the Audubon Society of Western PA at the observation area on the Great Allegheny Passage Bike Trail on July 4 from 10:00 am until 1:00 pm. They’ll have binoculars and spotting scopes on hand for you to see the eagles. Check their Facebook page for more information.
Click here for a map showing how to get there. –> Park near the Glenwood Bridge at Sandcastle’s back lot and walk less than half a mile on the bike trail.
(photos by Tom Moeller)