This month a flock of 100 to 200 common grackles has been hanging out at Frick Park, chattering in the trees and swirling in a dense flock whenever they’re disturbed. This is typical fall behavior for grackles and blackbirds but I wondered why they picked the park.
According to Birds of the World, common grackles (Quiscalus quiscula) are not very territorial during the breeding season and drop all rivalry in fall and winter. On migration and at overwintering sites they prefer to roost and feed in huge flocks, sometimes mixed with other blackbirds and some robins.
Common grackles roost near plentiful food but they don’t require wild places. Urban roosts are often favored on tree-lined streets or in parks. Their fall roosts in New Jersey can contain 3,000-500,000 birds (of which grackles comprise 33%).
This flock at Patuxent in Maryland looks to be 100% grackles.
The huge grackle flocks probably won’t stay in southwestern PA for the winter. By December they are further south, as shown on the eBird Dec-Feb map below.
Like elephants, albatrosses can hear low frequency sounds below our range of hearing, a skill that’s very useful for their lifestyle.
Wandering albatrosses (Diomedea exulans) spend their lives making incredibly long journeys over the ocean. They are known to circumnavigate the Southern Ocean three times in one year, a distance of more than 75,000 miles (120,000 km).
To do this with the least amount of effort, they have the longest wingspan of any living bird — 8 to 12 feet (2.5 to 3.66m) — and use the wind to glide as much as possible.
The best gliding happens at updrafts over the water and the best updrafts are caused by large waves. So how do wandering albatrosses find those large waves? They hear them from very far away, possibly 1,000 miles.
According to Science Magazine, “Big waves produce a very low frequency sound, below 20 hertz, that can travel thousands of kilometers, particularly when they collide with long distance swells, such as when storms develop.”
Would an albatross approach or avoid these waves in the Southern Ocean?
To figure out how the birds choose where to go, Samantha Patrick of University of Liverpool and her team tagged 89 albatrosses with GPS trackers at their breeding grounds on Crozet Island near Antarctica. When the birds returned a year later to breed again, researchers retrieved the tags and analyzed the data.
Geophysicists on the team combined the biologger recordings with infrasound monitoring data from Kerguelen Island in the Southern Ocean to build “soundscape” maps on the birds’ journeys. …
During their long-distance flights, the birds tended to change course whenever they encountered a loud infrasound, the team reports. The infrasounds often indicate wave turbulence, even storms—though it’s not yet clear how the birds make use of this information. The infrasound clearly impacted the birds’ behavior, although the scientists couldn’t identify a clear pattern of whether they avoided or aimed for these low frequencies.
When peregrine falcons migrate down the Pacific Coast in autumn they often pause at Canada’s Fraser River Delta to hunt shorebirds. Pacificnorthwestkate (@pnwkate) filmed one working a sandpiper flock at Roberts Bank.
Peregrines on the hunt hope to separate a single bird from the crowd because they cannot catch anything in such a tight flock. When a lone bird can’t keep up it becomes the peregrine’s dinner.
A new study, published this month in Phys.org, looked at the interaction from the peregrines’ perspective and found that the falcons haze the dunlin flocks to keep them moving. Peregrine hunting success improved at the end of those 3-5 hours of continuous flying because the dunlin had to stop for a rest.
The hunting data showed that dunlins were at greatest risk of predation just before and just after high tide, and spent most of the riskiest period flocking. However, there was a sharp increase in kills two hours after high tide, because the dunlins were not flocking despite elevated risk. [They were resting.]
So the dunlin changed their behavior to avoid peregrine predation and the peregrines changed their behavior to wear out the dunlin. Peregrines have more stamina that dunlin.
The region around the Gulf of Naples is very volcanic. There are vents at Solfatara in Pozzuoli where sulfurous steam emerges in an old crater. Pompeii and Vesuvius are across the Gulf.
Nonetheless it’s a lovely place to live by the Mediterranean. Towns, including Pozzuoli, Agnano and Bacoli, dot the crater edges and the flats between them. The area’s population is 500,000.
In September the magma under Campi Flegrei began shifting again and caused more than 1,100 earthquakes in a month, some as strong as 4.0 and 4.2 on the Richter scale. The Guardian reported on 3 October: “The Italian government is planning for a possible mass evacuation of tens of thousands of people who live around the Campi Flegrei supervolcano near Naples.”
Years ago I learned that birds can sense when an earthquake is coming and they take flight before it hits. I suspect that the birds at Campi Flegrei are flying more than usual lately.
Read more about birds and earthquakes in this vintage article from 2016.
Fallen leaves in Schenley Park, Nov 2016 (photo by Kate St. John)
6 October 2023
In October we see woolly bear caterpillars (Pyrrharctia isabella) out in the open crossing the trails. Woolly bears overwinter as caterpillars so this month they’re busy looking for the perfect place to spend the winter in leaf litter, under bark, or beneath a fallen log.
Woolly bear, Isabella Tiger Moth caterpillar, 3 Oct 2018 (photo by Kate St. John)
Leaf litter is key winter habitat for a lot of insects including springtails, millipedes, earthworms, butterflies and moths.
Millipede(*) Hays Woods, Sept 2023 (photo by Kate St. John)
If you’ve been thinking about “wilding” your yard — even just a little bit — now is a great time to start. Leave the leaves. You don’t have to leave it messy. Here’s advice on what to do.
Leaving the leaves and other plant debris doesn’t have to mean sacrificing your yard to the wilderness. The leaves don’t need to be left exactly where they fall. You can rake them into garden beds, around tree bases, or into other designated areas. Too many leaves can kill grass, but in soil they can suppress weeds, retain moisture, and boost nutrition.
Avoid shredding leaves with a mower. Raking or blowing are alternatives that will keep leaves whole for the best cover and protect the insects and eggs already living there.
If you decide you need to clean up the leaves and debris in spring, make sure you wait until late in the season so as not to destroy all the life you’ve worked to protect.
Take a break this weekend. Don’t bag those leaves! Just push them aside for wildlife.
(photos by Kate St. John and from Wikimedia Commons)
(*) p.s. The millipede was easy to photograph because it was dead, probably the victim of a parasitic fungus that prompts the millipede to climb high on a twig before it dies. I wrote down the name of the fungus when I took the picture but cannot read my writing. Perhaps it’s Anthrophaga myriapodia.
The blackpoll’s transoceanic path was proven in a 2015 study by Bill DeLuca and the Vermont Center for Ecostudies. VCE writes:
Bill DeLuca (Northeast Climate Science Center) and VCE solved this great modern-day avian mystery. Using light-level geolocators attached to Blackpoll Warblers in Vermont and Nova Scotia, DeLuca and colleagues documented the longest distance non-stop overwater flights ever recorded for a migratory songbird. During October, Blackpoll Warblers initiate a ~3-day non-stop transoceanic flight of ~2500 km from the north Atlantic Coast to Hispaniola and Puerto Rico. Radar data show migrating songbirds fly at 2,600 to 20,000 feet while making this journey. After a few weeks, they fly onto Columbia or Venezuela where they overwinter. Their spring migration route takes them over Cuba to Florida, where they journey up the eastern US seaboard to reach their breeding grounds in late May.
Of course I wondered if blackpoll warblers sleep in flight during their 3 day transoceanic trip, but we won’t find out any time soon. Blackpolls are way too small to wear the sleep monitoring gear used on the great frigatebird.
(photo from Wikimedia Commons, maps from eBird Weekly Abundance; click on the captions to see the originals)
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.
Two juvenile Cooper’s hawks in Frick Park, 14 July 2022 (photo by Charity Kheshgi)
22 September 2023
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.
Ecco watches while Carla preens, 15 Sep 2023, 3:54pm
16 September 2023
Yesterday Ecco and Carla spent lots of time hanging out together at the Pitt peregrine nest. The snapshot camera’s motion detector captured their activity.
Beginning at 3:50pm the pair spent 45 minutes together, bowing, preening, and watching. When Ecco left, Carla continued on the perch for another half hour, then stretched and departed at 5:00pm.
Two minutes later Ecco landed at the exact same spot on the perch. Because female peregrines are larger than males, the switch from Carla to Ecco made it look as if the bird shrank.
Ecco preened for more than an hour, then stretched and vaulted up to leave at 6:13pm. All told, the peregrines were present on camera for nearly 2.5 hours.
This slideshow shows 144 minutes of their interactions in only 1 minute and 15 seconds. If you miss the captions on the first pass, don’t worry, the slideshow repeats.
Except for a few rare sightings in Florida, flamingos seen in the U.S. are not from the wild, they’re escapees from a zoo. Then suddenly last week, after Hurricane Idalia, flamingos have been popping up all over.
At top, 16 flamingos visited Fred Howard County Park near Tarpon Springs, FL. Below, 6 flamingos stopped by St. Mark’s National Wildlife Refuge, 30 miles south of Tallahassee.
The groups have often been a mix of pink adults and gray youngsters.
As of Saturday evening the totals were:
100+ in Florida
11 at Pea Island, North Carolina
2 in South Carolina
2 in Virginia
3 in Alabama
5 in Tennessee
UPDATE on 4 Sep 2023: 1 in Kentucky
and 2 in OHIO! at Caesar Creek State Park. These were seen for only a day and then gone.
American flamingos (Phoenicopterus ruber) are native to the northern shore of South America, the Caribbean islands, Cuba, and the Yucatan in Mexico. Hurricane Idalia plowed through a few of those locations.
This WKRG video on 27 August shows Hurricane Idalia gaining strength as it spans the Caribbean, overlaying part of the Yucatan and all of Cuba. The flamingos would have felt it coming and flown north and northeast to get out of its way. Notice the lower speed winds (shades of green) on the edge of the weather map. The green wind track is where most of the flamingos have been found.
Considering the storm track, the flamingos are probably from Cuba and the Yucatan including at least one banded bird.
Given all the discussion about the flamingos now appearing all over Florida (and farther north), this eBird list from Amy Grimm is especially relevant. This afternoon, Grimm documented 8 flamingos at Marathon, in the Florida Keys, and noted that “One has large yellow band on the right leg code DXCL, small silver band on left leg.” Do the bands mean it’s escaped from captivity? No. This combination — yellow PVC band on one leg with 4-letter code in black letters, ordinary band on other leg — has been used for years in the ongoing project to band American Flamingos in the big colony at Rio Lagartos, on the north coast of Mexico’s Yucatan Peninsula.
