Category Archives: Bird Behavior

Leave The Leaves

Bird Behavior, Songbirds
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)

It also shelters salamanders and newts …

Red eft among the leaf litter in West Virginia (photo from Wikimedia Commons)

… and provides an insect hunting ground for birds including eastern towhees, dark-eyed juncos, robins and mockingbirds.

Eastern towhee, male (photo from Wikimedia Commons)

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. 

— Xerxes Society: Leave the Leaves: Winter Habitat Protection

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.

Do Blackpolls Sleep in Flight Over the Atlantic?

Bird Anatomy, Bird Behavior, Migration
Blackpoll warbler in PA, Oct 2020 (photo from Wikimedia Commons)

5 October 2023

Some birds are champion fliers, staying airborne for days or months at a time. Scientists wondered if birds sleep in flight and proved that they do in a 2016 study of great frigatebirds, finding that the birds either “sleep with one half of their brains active, or with both hemispheres shut down at the same time.” Read more in this vintage article, Asleep in Flight.

Blackpoll warblers (Setophaga striata) are also champion fliers making a non-stop fall migration over the Atlantic Ocean of 1,900 miles in 72 to 88 hours. Traveling at 27 mph, they launch from the east coast between Nova Scotia and South Carolina and fly to their only stopover in Puerto Rico or Hispaniola (Haiti & Dominican Republic), then on to northern South America.

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.

— Vermont Center for Ecostudies: Blackpoll Warbler

Notice in this eBird abundance map for the week of 2 Nov that blackpolls are:

  • bunched up on the East Coast from Massachusetts to North Carolina
  • at a stopover on Puerto Rico and
  • early migrants have already arrived in South America.
Blackpoll warbler weekly abundance map, week of 2 Nov 2007-2021 (map from eBird Status and Trends)

Watch them throughout the year in this eBird abundance animation.

Blackpoll warbler weekly abundance map (animation from eBird Status and Trends)

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)

ebird species migration weekly abundance trends

Young Red-Tail Hunts at the Hospital

Bird Behavior, Birds of Prey

28 September 2023

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.

Single-mindedness

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. 😉

(photos by Mary Tuttle)

Juvenile Cooper’s Hawks Learn to Hunt

Bird Behavior, Birds of Prey
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.

video embedded from PTZtv on YouTube

(credits and links are in the captions)

Peregrines Together in September

Bird Behavior, Peregrines
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.

(photos from the National Aviary snapshot falconcam at Univ of Pittsburgh)

Flamingos Have Been Popping Up All Over

Bird Behavior, Water and Shore, Weather & Sky

3 September 2023

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.
  • UPDATE on 7 Sept 2023: 2 flamingos in Franklin County, PA pictured below: First reported on eBird on 7 Sept but apparently present for 2 days prior as well.

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.

Range map of American flamingo (Phoenicopterus ruber) from Wikipedia

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.

video from WKRG News on YouTube

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.

— Kenn Kaufman at ABA Rare Bird Alert Facebook Group

Flamingo sightings will end as the birds head home. For now, enjoy them in videos.

video from Tampa Bay Times on YouTube
video embedded from @10TampaBay on YouTube

(credits are in the captions)

Out of Sight, But Not Out of Mind

Bird Behavior, Peregrines
Ecco and Carla bow at the nest, 31 August 2023, 4:17pm (photo from the National Aviary snapshot camera at Univ of Pittsburgh)

1 September 2023

The National Aviary’s streaming camera is off for the season so the Pitt peregrines are virtually out of sight, but they are not off my mind. Every day I check the Cathedral of Learning’s ledges to see where they’re perched and I look at the snapshot camera in case they’ve been to the nest.

Activity at the nest picked up this week because fall is coming and migration is underway. The length of day is similar to spring and they’re taking an interest in songbird migration as prey flies overhead at night.

Ecco and Carla bowed at the nest three times yesterday, including an extended bowing session, to strengthen their pair bond and their claim on the nest.

All of Pitt’s resident peregrines(*) stay home for the winter and I expect Ecco and Carla to do the same. They don’t need to migrate because there’s plenty of food in the winter (pigeons and starlings) and their “cliff” is too valuable to lose by vacating it for six months.

So I’m still watching. The Pitt peregrines may be out of sight but they are not out of my mind.

(*) There’s a lot of history that allows me to say that. Peregrines have lived at the Cathedral of Learning for 22 years, spanning 8 adult birds.

(photos from the National Aviary snapshot camera at Univ of Pittsburgh)

Sleeping On Migration

Bird Behavior, Migration
Sparrow asleep in New Mexico (photo by Larry Lamsa via Flickr Creative Commons license)

31 August 2023

Migration is exhausting work and since warblers migrate at night, they must rest and refuel during the day. Food and good cover are both essential at their rest stops. Sleeping is a dangerous activity where predators lurk.

A study published in Current Biology, August 2019, revealed one way that migrating warblers manage these dangers and demands: They adjust their sleep postures depending on their physical condition and physiological needs. Plump, well-muscled birds tend to sleep with their heads held upright, while scrawnier warblers tuck their heads into their feathers, a posture that makes them more vulnerable to predation but helps them conserve their much needed energy.

— New York Times: Some Migratory Birds Sleep Better Than Others, August 2019

Fit warblers can afford to be vigilant. They puff up and sleep in a watchful posture, sometimes out in the open. This makes them ready to escape at a moment’s notice.

Sardinian warbler asleep on a branch (photo from Wikimedia Commons)

Exhausted warblers hide in thickets and tuck their heads under their wings. This provides much needed rest and protects against heat loss but makes them vulnerable to predators. Interestingly, these same birds sleep less than those in good condition because they have to spend more time foraging.

Bird sleeping with head tucked under wing (photo from Wikimedia Commons)

Some long distance migrants, such as the ocean-going great frigatebird, can sleep in flight.

Great frigatebird in flight (photo from Wikimedia Commons)

A 2016 study equipped great frigatebirds (Fregata minor) with EEG equipment and proved that they sleep while flying though they get less sleep in the air than on land. Read more in this vintage article.

Asleep In Flight

It would be nice to safely sleep while doing other things. Yawn! I’m ready right now.

(photos from Wikimedia Commons, see links in the captions)

Peregrine Family Life in August

Bird Behavior, Peregrines
“Mother and son on the ledge right now” 17 July 2023 (tweeted by @FaBPeregrines)

25 August 2023

Because the Pitt peregrines had no eggs this year I miss seeing their young on camera. To fill that gap I’ve been following the Fulham and Barnes Peregrines at Charing Cross Hospital in London, UK whose daily lives are chronicled by @FaBPeregrines.

Azina, Tom and their son P6T (named for his band number) are frequently seen on camera, even in late August. P6T’s dispersal from his natal site is on a later schedule than we’re used to in Pittsburgh.

Juvenile peregrines in Pittsburgh fledge in early June and leave in July. At Fulham and Barnes, P6T fledged in the fourth week of May and is still hanging around in late August. His persistence gives us an opportunity to watch a peregrine family in late summer when the youngster hunts on his own.

Notice how the ledge is cluttered with prey on 23 August compared how clean it was on 17 July, at top . Someone has been messy. 😉

Follow this peregrine family @FaBPeregrines on X, formerly known as Twitter.

(tweeted by @FaBPeregrines)

Never Use Sticky Tape for Lanternflies! It Kills Birds!

Bird Behavior, Insects, Spotted Lanternflies
embedded photo from Audubon News: Downy Woodpecker found in Brooklyn. Photo: Sarah Valeri

22 August 2023

Invasive spotted lanternflies are swarming over Pittsburgh right now, especially near the railroad tracks. Everyone wants to kill them but the first solution that comes up on any Google search is a very, very bad one. NEVER EVER use sticky tape to capture insects. Glue tape kills birds!

Audubon News, the source of the embedded photo above, wrote about the hazards of glue tape last March: Meant to Catch Spotted Lanternflies, Glue Traps Are a Horrifying Hazard for Birds. Only 10% of the trapped birds survive, even if they’re taken to a rehabber.

Raven Ridge Wildlife Center in Lancaster County, PA has years of experience with the harm caused by glue tape. This Facebook report from 17 August 2023 is just one of them. Three of the four trapped woodpeckers died and the fourth is in trouble.

So what can you do to kill lanternflies?

For trees use the Circle Trap. You can make it yourself. Instructions found here.

For home, make a simple vinegar trap :

Spotted lanternfly and insect vinegar trap (photo by John English)

Straight white vinegar plus dish liquid — maybe a 1/2 tsp — to break the surface tension. (Insect by-catch in this photo: a cicada.) Thanks to John English for this suggestion.

For personal combat there are lots of solutions: Electric “Tennis Racket” bug zappers, the Bug a Salt Gun, etc. found via Amazon searches.

Electric “tennis racket” bug zappers via Amazon search
The Bug a Salt gun via Amazon search

Watch a champion spotted lanternfly killer use these tools in a video from VICENews:

video from VICENews on YouTube

p.s. Why are spotted lanternflies more prevalent near railroad tracks? They arrived as egg masses stuck to railcars and hatched from there. Their host tree is the Ailanthus, an invasive weed that grows along the rail lines. They were first found in southwestern PA at a rail yard in Beaver County in 2020.

(photo and video credits are in the captions)