On 31 July my sister watched more than two dozen tree swallows swarm over her yard in Tidewater Virginia. They were feasting on flying bugs for about 20 minutes, and then they were gone.
After they finish breeding, tree swallows (Tachycineta bicolor) gather in ever-growing flocks in July and August and begin their southward migration. In transit they seek out swarms of insects that may include true flies (Diptera), dragonflies and damselflies (Odonata).
Peak tree swallow migration occurs in early to mid-fall. I was at Cape Cod on 1 October 2017 when I witnessed a huge flock at West Dennis Beach. Abundant bugs attracted the tree swallows; abundant swallows attracted a falcon who captured one in his talons (top right of photo below).
If you live in the Mississippi or Atlantic flyways, or at their wintering grounds in Florida or Louisiana, there’s still time to see swarms of tree swallows. Watch their annual movements in this weekly abundance animation from eBird.
Yesterday it was at or near 90°F for most of the day. No peregrines were visible when I walked around the Cathedral of Learning at 11am but by 5:45pm the nestbox area had been in the shade for several hours and had cooled off enough to attract Ecco and Carla.
Peregrines are not courting at this time of year but when a pair stays on territory year round they develop and maintain their pair bond through bowing at the nest. Yesterday they bowed for eight minutes at 5:45pm, then joined each other for 16 minutes at 6:20pm.
The question sounds foolish but … Can pigeons play Wordle?
Seven years ago a pigeon behavioral study found that the birds can recognize 4-letter English words and tell the difference between real words and mere jumbles of letters. This was the first time anyone knew that a non-primate species had this ability.
Their 4-letter prowess is described in the vintage article below. Do you think they can they deal with 5 letters? Can they play Wordle?
Midway Atoll hosts the largest Laysan albatross (Phoebastria immutabilis) nesting colony in the world where more than 600,000 pairs raise young each year. The birds are absent in September but return to court in November, lay eggs in December, and hatch in February.
There are so many birds that it’s hard to count.
After the eggs hatch the chicks begin to wander in March while their parents hunt at sea. By May the chicks start to grow adult feathers but it will take two more months before they are ready to fledge in July. During this period they are everywhere …
In open spaces …
… near buildings …
… under trees and on the roads.
On the Fourth of July a rain shower prompted the chicks to flap their wings, shown in two videos below. You can hear the raindrops on the audio tracks.
Thousands of young Laysan albatross simulate flying by flapping their wings during a rain shower at Midway Atoll National Wildlife Refuge, July 4, 2024. (video by USFWS volunteer Dan Rapp)
As soon as they fly, Laysan albatross youngsters leave Midway for a life at sea. USFWS Pacific says they are “likely to move towards Japan or Alaska, but their known range extends to Mexico, too.” They won’t return to Midway Atoll until they are three years old. They don’t breed until age seven or eight.
Our largest swallow, the purple martin (Progne subis), has a very short breeding period in North America. In Pennsylvania they arrive in late April and fledge young in mid July.
As soon as the fledglings fly well, adults and young leave the nesting area and spend their nights in a communal roost.
Flocking begins as soon as nestlings fledge; birds of all ages assemble in roosts before fall departure. This may represent nonbreeding activity rather than a specific response to upcoming migration, because the species is highly social and flocks in large roosts throughout the overwintering period.
Since the breeding period is earlier in the South, roosts in the Carolinas fill up in July and contain so many birds that their early morning departure can be seen on weather radar. This happened last week in Wilmington, North Carolina.
Flowers, insects and birds were active this week though the end of the week was so humid that it felt like the tropics. Here’s a trail of photos from Duck Hollow, Aspinwall Riverfront Park, Schenley Park and my own neighborhood.
Don’t forget to check out the two photos at the end: A mystery match-the-leaves moth or butterfly and some amazing bird behavior.
With false sunflowers (Heliopsis helianthoides) at their peak in Schenley Park, the red aphids are out in full force.
Wineberry is already forming fruits.
I found a moth or butterfly that I could not identify at Duck Hollow. It was impossible to get close for a photo so this is the best I could do. Perched on Japanese knotweed. Can you tell me what it is?
And here’s some bird behavior I’ve never seen before: Two red-tailed hawks are perched on the hoist rope of this enormous crane on O’Hara Street near Thackeray on 29 June. This crane spends five days a week moving back and forth. I’m amazed that they decided to test it on a Saturday. Can you see them? If not, click here for a marked-up photo.
p.p.s. See Karen’s comment below in which she identifies it as a Bad-wing moth (Dyspteris abortivaria). So my next question is, Why is it called a bad wing? –> And see J’s comment with the answer!
In May I encountered a building that showed me how to think like a bird. Here is the building. What do you see?
Sky. Trees. Four buildings. Railings. Stairs.
At street level we see stairs, railings, trees, white buildings but not the building we are close enough to touch. The Effron Music Building at Princeton University virtually disappears in its reflections.
Facing the glass you can see through it to suspended wooden practice rooms, yet the surface of the Effron Music Building still reflects its surroundings.
Now, imagine you are the size of a songbird.
What do you see instead of the window glass? Leaves. Branches.
What do you see instead of the glass? Sky. Trees.
What do you see here? Lots and lots of trees and an inviting backyard to fly into.
These optical illusions are why glass kills one billion birds every year in the U.S. That’s 2.7 million birds per day.
Towering skyscrapers might seem like the most obvious culprits [of bird deaths], yet Loss’s team found that 56 percent of the mortality occurs at low-rises (4-11 stories tall); 44 percent at residences (1-3 stories tall), and less than 1 percent at high-rises (12 stories and up).
56% of the deaths are at 4-11 story buildings: offices, apartments and academic buildings such as 5-story Craig Hall at Pitt where a juvie peregrine died in 2012.
Low-rise buildings are more likely to cause bird deaths when they reflect trees in the glass. I noticed that the Effron Music Building does not have greenery anywhere near the reflective surface so it probably doesn’t cause many bird deaths.
Our homes, however, have landscaping that reflects on the glass. 44% of bird deaths are at 1-3 story residences.
Do birds hit your windows at home? Take a look at your windows. Think like a bird. What do you see?
PREVENT BIRDS FROM HITTING YOUR WINDOWS AT HOME: Reflective glass must be treated on the outside to alter the entire look of the windows. The treatment must make the birds see a wall or a mesh too small to fly through. Here are tips from Fatal Light Awareness Program in Toronto and the American Bird Conservancy
If you watch peregrines you know how improbable it is that you will ever see one make its first flight. In 23 years of watching peregrines I’ve seen it once, maybe twice. I have no photographic evidence but I know of two Pittsburgh examples.
So what does it look like when a peregrine chick makes its first flight? Wakefield Cathedral, UK (@WfldPeregrines) has so many cameras on their peregrines that the moment was captured on 17 June.
Yesterday morning when the heat index was 96°F, Carla sunbathed for 20 minutes at the Pitt peregrine nest. Her fanned tail shows us why she was doing it. Not only does sunbathing kill feather lice, it eases the discomfort of molting. Carla is molting her tail feathers two at a time.
Carla began her sunbathing session after she and Ecco bowed briefly over the scrape. She might have stayed longer but her youngster “Blue” showed up. Carla and Ecco are both avoiding their “kids” in an effort to make them independent.
Carla and Ecco bow at the nest, 26 June 2024 11:26am