Watering holes are places of abundant wildlife in Arizona’s Sonoran desert as captured on this trail cam in the borderlands. One of the night visitors is a ringtail (Bassariscus astutus), a member of the raccoon family, shown above. (There are two embedded videos below; please wait for them to refresh.)
When water crosses political boundaries animals cross, too, back and forth from Arizona to Mexico. But now the Border Wall makes most of that impossible.
In 2013 US Fish & Wildlife proposed an experiment: Kill 3,600 barred owls (Strix varia) in the Pacific Northwest to keep them away from their close relative, the northern spotted owl (Strix occidentalis). Barred owls had spent 100 years expanding westward to the Pacific coast where they became more successful than their habitat-constrained spotted cousins and even interbred with them. Though barred owls are native to North America and moved west on their own, USFW dubbed them “invasive” and proposed killing them wherever found near spotted owls.
Nationwide comments on the culling proposal were overwhelmingly negative but local comments were in favor. The experiment went forward and barred owls were killed according to plan. The final paper describes barred owl “removal”.
Barred owls detected in treatment areas were removed using 12-gauge shotguns and well-established field protocols (20, 22, 23). A total of 2,485 barred owls were removed from treatment segments of five different study areas during the experiment (Table 1). The mean number of barred owls removed per year was highly variable among study areas, ranging from a low of 15.8 barred owls per year in Green Diamond (GDR), to a high of 251.5 barred owls per year in the Oregon Coast Range (COA).
The five locations where removal occurred, called “treatment” areas, and the number of barred owls killed are shown in the screenshot of Table 1.
Interestingly at two of the five study sites — Hoopa-Willow Creek and Green Diamond, California — the killing of 494 barred owls made little to no difference for the spotted owls. Click here for the graph that shows this.
However, USFW declared the experiment a success and recently drafted a new “Barred Owl Management” proposal to continue killing barred owls and expand the project further in California. The draft is currently in its 60-day public comment period: November 17, 2023 – January 16, 2024 during which we are free to express our opinion.
Public Comments Processing; Attn: Docket No. FWS-R1-ES-2022-0074
U.S. Fish and Wildlife Service Headquarters, MS: PRB/3W
5275 Leesburg Pike
Falls Church, VA 22041–380
p.s. Here’s what I thought of this idea 10 years ago. I haven’t changed my mind.
Songbird migration is quiet now and birds, when they’re found, are in mixed species flocks.
On 7 November, Charity Kheshgi and I encountered agitated golden-crowned kinglets, tufted titmice and dark-eyed juncos but it took us a while to find what they were upset about. This red morph screech-owl was hiding above our heads in a small oak.
An exception to the mixed species flocking rule is our “murder” of crows. My guess is that Pittsburgh’s winter crow flock is 90% American and 10% fish crows, but who can tell? They look alike.
In late afternoon crows stage in the trees in Shadyside and Squirrel Hill, then head west at sunset. 6,000 to 10,000 pass by my building on their way to the roost.
At sunset black birds in a darkened sky are impossible to photograph but it’s another story at sunrise. Click on the photo below for a closeup of crows in the brightening sky.
Leaves littered the ground this week and the air was filled with the sound of leaf blowers. 🙁
Most of the trees were bare in Schenley Park by Friday 10 November.
And finally, a reminder that the rut is still in progress and deer are crossing roads. This duo showed up at a Squirrel Hill polling place on Election Day at a place surrounded by roads. So watch out.
On 18 October while Jim McCollum was taking photos of the Hays bald eagles a raven showed up and began to harass the new male eagle, nicknamed “V.”
10/18 – The new fella went for a fly about and got jumped by a Raven. The Raven chased him all over the sky. This guy needs to work on his fighting skills.
A little tidbit I read recently. Crows will lite on eagles backs and peck at their necks. The eagles don’t fight back just soar higher and higher until for lack of oxygen the crow passes out and falls off the eagles back. I’m not sure about the validity but it’s a good story!
At what altitude does lack of oxygen affect birds?
Birds are the champions of high altitude and can breed and exercise (fly) at altitudes that kill humans. Some species are so well adapted to high altitude that they fly as high as a jet, over the Himalayas where humans die without supplemental oxygen. Even our North American songbirds fly high …
Migrating birds in the Caribbean(*) are mostly observed around 10,000 feet, although some are found half and some twice that high. Generally long-distance migrants seem to start out at about 5,000 feet and then progressively climb to around 20,000 feet.
In case you missed it (ICYMI) there’s a new resident male bald eagle at Hays. The old male disappeared in early September. The new guy was obvious by late September.
“Dad” was one of the original eagle pair at Hays where nesting began in 2013. Pictured below in 2020 they fledged 20 youngsters in 10 years. The female was 4-5 years old when she arrived (14-15 years old now), but he was a full adult so no one knew his age. Bald eagles can live 30 years.
The newcomer, nicknamed V for visitor, became obvious as he set out to accomplish two important things in his early days of residence.
Vigorously defend his new territory against other males,
Court his new mate and cement their pair bond.
This extra level of activity drew Hays eagle fans’ attention to his presence. Viewers have seen V chase away other bald eagles and mate with the Hays female.
This is typical behavior among new peregrines, too. Long time residents don’t work hard to show who’s boss, but the newcomers do. The first time it happened at the Cathedral of Learning peregrine nest it took me a while realize that new behavior was a clue. See how I figured out the first male switchover at Pitt in this vintage article: Who is he? New male at Pitt.
Meanwhile V and the Hays female will be busy getting to know each other as nesting season approaches in December.
On Saturday 17 September, my friends Mary and Bea were walking to the Bloomfield Saturday Market when they couldn’t help but notice a red-tailed hawk (Buteo jamaicensis) hunting on the lawn at Shadyside Hospital. Mary stopped to take his picture.
Perched on the blue sign, I can tell the bird is immature because his tail isn’t rusty red. In early June he was still in the nest. Soon he learned to fly, then to hunt. Now, months later, he can feed himself but he’s not an expert. It takes time and luck to get a meal.
In autumn young red-tails disperse on their first migration and every place they stop is completely new to them. Those that grew up in urban environments are unbothered by traffic and people so they may gravitate to open areas near buildings in search of prey.
This hawk was so focused on hunting that he ignored Mary while she took his picture. Read more about the hawk’s single mindedness in this article from 2009.
p.s. This red-tail may have been attracted to the noise of house sparrows tweeting inside that bright green hedge. There are always lots of them in there, but they shut up as soon as I look so I rarely see one. As far as I know, I’m the only one — other than a hawk — that peers inside that hedge. 😉
Every year young Cooper’s hawks (Accipiter cooperii) fledge in June/July and learn to hunt in July/August. As soon as they’re self sufficient they disperse, and then they start to migrate.
Cooper’s hawks eat birds for a living so they migrate with their prey. Their peak migration continues now through mid October at the Allegheny Front Hawk Watch.
How did they get to this point? Let’s take a look back to August as some young Cooper’s hawks perfect their hunting techniques in New Jersey. It involves a lot of jumping.
The three owls pictured here live in Pittsburgh’s city parks but are hard to find in August. The best time of year to see a great-horned owl, above, is in late winter or early spring. Steve Gosser photographed this one in Frick Park in April 2019.
Though barred owls have nested successfully in Frick Park, I didn’t see any this year. In July 2022 two youngsters ventured further from their parents at dusk, photographed by Charity Kheshgi.
This roost on the main trail in Schenley Park was the best place to find an eastern screech-owl in winter, but it has not been used for several years. Nowadays listen for angry songbirds to tell you about the owls. They told me where to find a young eastern screech-owl in early June.
Last week I mentioned the Eurasian eagle-owl, Flaco, who lives in Central Park, NYC.
Happy 6th month of freedom today to Flaco, the Central Park Eurasian eagle-owl. When I saw him hunt for possibly the first time, I was surprised and glad. He hunts with ease now and I am happy for his continued success and wellbeing! Photo taken recently after midnight.#birdcpppic.twitter.com/RNirtnBjeG
A decade ago we thought climate change was a slow moving train but now it’s heating up so fast that new calculations predict we will hit the +1.5°C (2.7°C) global temperature mark in the next five years. The National Audubon Society’s Climate Initiative predicts that most bird species will shift northward. Unfortunately our national symbol, the bald eagle, will leave much of its favorite range in the U.S.
… The Audubon Society predicts that three-quarters of the bald eagles’ current summer range will become unsuitable for the birds in about 60 years.
“A lot of their breeding is going to shift completely into Canada and Alaska. So the lower 48 is looking less ideal for breeding conditions for the species,” said Brooke Bateman, senior scientist at the National Audubon Society.
At +1.5°C — in the next five+ years — the biggest decrease will be in a swath of the Southeast and Lower Mississippi Valley. This screenshot map of bald eagle climate vulnerability is tiny on purpose so that you’ll view it on the Audubon website. Click here, then scroll down to see the maps for winter/summer.
A global temperature rise of +3.0°C will reduce bald eagle nests in a huge swath of the U.S. from Maryland, Virginia and North Carolina westward to Nebraska and Arkansas. This is unhappy news for Pittsburgh where red indicates a 15% loss of bald eagle nests under the +3.0°C scenario. [Again, view this map on the Audubon website. Click here, then scroll down to see the maps for winter/summer.]
Sadly, climate change will prompt our national bird to move away from home.
Read more about the Audubon climate change report at Yale Climate Connections. See the affect of climate change on the bald eagle’s range in the Audubon Field Guide:
Last week while in Tidewater Virginia, I noticed that turkey vultures dominated the airspace. On our way to Pittsburgh yesterday, soaring red-tailed hawks made me feel like “I’m home.”
Red-tailed hawks (Buteo jamaicensis) live quite near us in southwestern Pennsylvania, especially in the city. Here are a few shots of our most common hawk, thanks to local photographers.
(photo credits in the captions, click on the links to see the photographers’ websites)