Category Archives: Nesting & Courtship

Now The Rain Gets In

18 November 2020

It didn’t rain much last July but when it did I noticed something puzzling on the Pitt peregrine falconcam(*). The nest was getting wet where it ought to be dry. Was the roof leaking?

A week ago the problem became acute when it rained hard all day on 11 November. By the end of the day pieces of brown debris were on the nest surface, probably from the roof. Now the rain really gets in!

If you look closely at falconcam still photos you can see papery pieces of roof hanging from above, erosion in the right corner where the rain drips, and debris from the roof on the nest surface.

Though we can’t see the roof from either camera, a snapshot of the awning gives us a hint of the roof’s condition. The red circle shows a place that lost its waterproof coating, exposing the under layer. The awning is deteriorating too, though more slowly.

The nestbox was built and installed in late 2007 (or early January 2008) after the Cathedral of Learning was spray-washed. I believe the box and walls are made of solid plastic but the roof and awning appear to be a composite material that has been weathering for 13 years.

This fall we’ll arrange for repairs so the nestbox is in good condition for the 2021 nesting season. Like maintaining a very small home, repairs are inevitable.

(*) Streaming of the Pitt peregrine falconcam is seasonal. It ended for the year on 31 July 2020.

(snapshots from the National Aviary falconcams at Univ of Pittsburgh)

If You Think Cowbirds Are Bad …

Just like brown-headed cowbirds (Molothrus ater), common cuckoos (Cuculus canorus) in Eurasia are obligate brood parasites that never raise their young. Cuckoos lay their eggs in the nests of smaller birds that foster the cuckoo chicks as their own. A stark difference between cowbirds and cuckoos, though, is their size. Cuckoo chicks can be 10 times larger than their hosts!

Compare the Eurasian reed warbler (Acrocephalus scirpaceus) feeding a common cuckoo chick, above, to the brown headed cowbird chick with its song sparrow (Melospiza melodia) foster parent below.

Brown-headed cowbird chick begging from song sparrow host (photo from Wikimedia Commons)

The cowbird is slightly larger than its host but the cuckoo chick when it leaves the nest will be 10 times the reed warbler’s weight.

This situation can be even more bleak, as shown in a Twitter post by John Deakins.

So if you think cowbirds are bad, consider common cuckoos.

p.s. I asked folks to tell me the identity of the foster parent standing on the chick’s back. Janet Campagna suggests meadow pipit — which looks right to me. Meadow pipits are one of three species most often parasitized by common cuckoos.

(photos from Wikimedia Commons plus an embedded photo from Twitter; click on the captions/tweet to see the originals)

Last Round of Cowbird Babies

Brown-headed cowbird youngster begs from a song sparrow foster parent (photo from Wikimedia Commons)

On a late July visit to Washington’s Landing (Herr’s Island) I saw two song sparrow families with begging fledglings. Unfortunately the begging youngsters were brown-headed cowbirds, not song sparrows.

Female brown-headed cowbirds lay their eggs in the nests of smaller birds.  Each cowbird chick is raised, not by its own mother, but by foster parents of another species. To make matters worse, cowbird parents lurk near the foster nest to make sure their own baby survives. They remove the host’s eggs or kill the foster parents’ young to give their own chick a better chance.

Cowbirds parasitize many species but are especially fond of song sparrows and yellow warblers. Yellow warblers are well aware of cowbird eggs and will “abandon” the nest by building a new nest on top of the old one. Experienced song sparrows get upset but don’t have an immediate solution.

However, song sparrows have a secret weapon — their breeding season is longer. Their first of two to four broods may begin before cowbirds are ready to lay eggs while the last nest starts after cowbirds are done.

In Pennsylvania brown-headed cowbirds stop laying in early July while song sparrows are still going strong. What I saw at Washington’s Landing was this year’s last round of cowbird babies.

(photo from Wikimedia Commons; click on the caption to see the original)

The Threesome Continues

27 July 2020

Last Friday Mary Ann Pike noticed that Terzo and Morela were spending a lot of time at the Pitt peregrine nest and commented:

Seems like Morela and Terzo have been swapping shifts at the nest today. I saw Morela this morning, then Terzo early afternoon for a while, now Morela is there again. What a strange situation with Ecco in the mix. I wonder if he hangs around Oakland somewhere when he’s not on camera. It seems like the other 2 must be spending most of their time in Oakland but under normal circumstances they wouldn’t let a third Peregrine hang around.

Mary Ann Pike, 24 July 2020, 4:33pm

We didn’t realize it on Friday but Terzo and Morela were probably vigilant because Ecco was nearby. He appeared on camera before dawn.

In the video below Ecco arrives at 5:33am to bow with Morela. After he leaves Morela pauses for 45 seconds, then we hear a peregrine wailing at 3:28 in the video. The wailing continues intermittently over the next three minutes. Was it Terzo complaining that Ecco was there?

The rest of 24 July was very busy. Morela and Terzo bowed at 8:30a and 3:30p.

Morela and Terzo court, 24 July 2020, 8:30am

Terzo sunbathed and watched for two hours.

Then Morela hung out and preened for three hours. I’m happy to see that Morela’s flipped primary feather is gone.

Terzo and Morela courted at dawn on Sunday morning. There was no sign of Ecco but I’m sure he’ll return.

However, the threesome continues at the Pitt peregrine nest.

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

p.s. The National Aviary falconcam streaming service ends on 31 July 2020. It will resume next February.

Young Raptors As Home Wreckers

Immature bald eagle, March 2015 (photo by Steve Gosser)

Something is happening among nesting bald eagles in the James River watershed that may explain what we’re seeing among peregrines in western Pennsylvania. There are lots of eagles at the James River but less nesting success than in the past. The Center for Conservation Biology in Williamsburg, Virginia has figured out why.

CCB has been conducting bald eagle nesting surveys every March since the 1970s. Seven years after DDT was banned they found only one pair of bald eagles in the watershed. This year there are 319 pairs.

Meanwhile, “eagle productivity has dropped as the population has grown and breeding density has increased.” The number of eaglets per nest peaked at 1.6+ in the mid 1990s but has dropped to only 1.05 today.

Lower nesting success is not a food problem, it’s a competition problem. CCB explains:

The mechanism causing the decline does not appear to be traditional resource competition where pairs scramble for their share of limited fish. Rather, the mechanism appears to be young marauding eagles that are disrupting territory holders and competing for a limited set of viable breeding territories.

Young bald eagles are harassing adult pairs in an attempt to gain a territory — so much so that some pairs fail to nest successfully.

Adult and immature bald eagles jousting (photo by Steve Gosser)

This sounds like what happened at the Cathedral of Learning peregrine nest this year. In February a young male, Ecco, showed up at the Pitt nest and persistently vied for the site — so much so that Morela didn’t lay eggs until May and her eggs were never incubated. Hmmmm.

Young bald eagles are home wreckers. Maybe young peregrines are, too.

Read more about the James River bald eagle population at CCB’s James River Eagle Population Continues to Soar While Productivity Continues to Fall.

(photos by Steve Gosser)

Song Sparrow Babies At The Nest

Song sparrow nestlings and parents, 12 July 2020 (screenshot from Bob Donnan video)

17 July 2020

This month a pair of song sparrows is nesting in a hanging basket above Bob Donnan’s deck in southwestern Pennsylvania. Bob wanted to see them better without disturbing them, so he set up a nest camera and is publishing YouTube videos of their activity. This week the babies grew a lot.

Bob’s 12 July 2020 video opens with both parents feeding four nestlings. Only about three days old, the nestlings are featherless and their eyes are closed. After the feeding ‘papa’ bird leaves while ‘mama’ remains to tidy the nest. She picks up something that looks like a worm and eats it — a fecal sac from one of her nestlings.

Later we hear ‘papa’ sparrow singing in the background while ‘mama’ shelters her young and appears to pant. It’s hot. Bob has been trying to provide extra shade because the sparrows’ air traffic has made the flowers droop. (Click here or on the screenshot at top to see the 12 July video.)

Three days later, 15 July, the babies are growing fast. The three remaining nestlings jump up to feed when mama arrives. They look so tall! Click on the image below to see Bob’s 15 July video.

Song sparrow nestlings, 15 July 2020 (screenshot from video by Bob Donnan)

Song sparrows babies mature so fast that they leave the nest at only 10 days old, even earlier in the heat of summer.

The nest on Bob’s deck will be empty soon. You have to look quickly to see song sparrow babies at the nest.

p.s. Bob has a great selection of “how to” landscaping videos on his Bobscaping YouTube channel.

Follow-up videos: (18 July) Junior! Get Back in the Nest!

(screenshots from videos by Bob Donnan; click on the images to see the videos)

Pair Bonding With Ecco

Ecco and Morela touch beaks at the Pitt peregrine nest, 11 July 2020, 5:45am

13 July 2020

It’s almost mid-July yet two peregrine falcons, Ecco and Morela, are pair bonding at the Pitt peregrine nest in a very serious way. On Saturday 11 July they courted twice and touched beaks in a close bond before dawn.

For five months Morela has had two suitors, Terzo and Ecco. In early June Terzo was a constant presence, then Ecco reappeared on 16 June and both males courted her twice on 25 June. After that Terzo faded away and Morela was alone until Ecco reappeared on 9 July.

I should have seen him coming. My first hint was when Morela spent five hours roosting at the nest rail on the night of 8-9 July from 9p to 2a. Female peregrines usually don’t roost at the nest outside the breeding season. Here she is on the 8 July 2020 “Night in a Minute” video.

The next morning, Morela and Ecco courted for almost four minutes.

The 10th of July was quiet but they returned before dawn on 11 July, courting for three minutes and touching beaks. Beak-touching is more intimate than merely bowing. These two are hitting it off as a couple.

Less than three hours later, at 8:27a, Morela returned with a full crop and courted with Ecco for another three minutes.

I don’t put a lot of stock in the permanence of Morela’s bond with Ecco since he and Terzo trade places so often. However, it’s intriguing to see that she’s so close to Ecco.

Meanwhile, here’s something to ponder …

Why does Morela have a flipped primary feather?

Female peregrines usually molt their primaries during incubation (April/May) so I was surprised to see one of Morela’s primaries is flipped on her right wing. The feather was normal until the morning of 27 June when Morela returned to the nest rail. She preened and stayed there for five hours as shown in the Day in a Minute video .

So far the flipped feather has stayed in that position for 16 days. If it had flipped due to molting, the new feather would have pushed it out by now. So I wonder, was Morela in an aerial battle on 27 June? Even if we knew the answer, we’ll never know who her adversary was.

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

Piping Plovers Dance For Love

Piping plover at West Meadow Beach, NY (photo from Wikimedia Commons)

7 July 2020

For such a tiny shorebird, male piping plovers (Charadrius melodus) have an elaborate courtship dance. The best part of it — the “tattoo” — was tweeted last Friday by the Ontario Piping Plover Conservation Program.

There’s more to the dance than that. In the run-up to copulation the male

  • Calls to his mate while scraping a nest in the sand, tossing away twigs and debris.
  • Approaches her in a low gliding crouch with his head below the horizontal.
  • Pauses near her, raises his head up high and beats a tattoo with his feet, faster and faster, closer and closer.
  • When he’s ready he mounts, still moving his feet up and down while on her back. He may stay in this position without copulating for more than a minute.
  • After or during copulation he may grab her by the nape of the neck. Though this looks vicious she doesn’t seem to mind.
  • And then they walk away and preen.

You can see all of these behaviors in this longer video from Montrose Beach, Illinois.

If all goes well, the dance results in some very cute baby birds.

Piping plover chick at West Meadow Beach, NY (photo from Wikimedia Commons)

(photos from Wikimedia Commons; click on the captions to see the originals)

What Peregrine Season Might Have Been

Return of the Peregrine Trailer from Brian McClatchy on Vimeo.

5 July 2020

Pittsburgh’s peregrine nesting season was disappointing this year, from the failed on-camera nest at the Cathedral of Learning, to the many un-monitored nests during the COVID-19 shutdown.

As compensation here’s the trailer for a beautiful 2013 video, The Return of the Peregrine, filmed in Germany.

This is what peregrine season might have been. Fingers crossed for next year!

(video embedded from Vimeo)

Not The Soap Opera We Thought

Ecco with Morela at the Pitt peregrine nest, 3 March 2020

2 July 2020

This spring the unresolved rivalry between two male peregrines — Terzo and Ecco — at the Cathedral of Learning made for a disappointing nesting season but generated a lot of speculation. Now that we know more about the Downtown peregrines we can lay one bit of speculation to rest.

Back on 15 March when Terzo and Ecco’s rivalry was spinning like a revolving door, I was surprised to see the Downtown female peregrine Dori appear on camera at Pitt. At the time I couldn’t help wondering, “Is the unbanded male Dori’s new mate who is shopping in Oakland because he doesn’t like the Downtown site?” … This led to speculation that Ecco was two-timing between the two nests. No, he is not.

Ecco has not been two-timing between Pitt and Downtown because (1) he’s not Dori’s mate and (2) he would have been way too busy Downtown to visit Morela at certain critical times.

Dori’s mate: On 28 June we learned from Lori Maggio’s photos that the Downtown male peregrine is banded. (Ecco is not banded.)

Adult male peregrine with silver colored right leg band, Downtown Pittsburgh, 2020-06-28 (photo by Lori Maggio)
Close-up of silver colored right leg band on Downtown Pittsburgh adult peregrine, 2020-06-28 (photo by Lori Maggio)

Critical timing: Here’s one example.

We learned on 28 June that the Downtown peregrine nest produced at least two young, probably more, who fledged approximately 25 to 30 June 2020. Parent peregrines are always extremely busy during the fledging period as they watch, feed and protect their naive young. During that period the Downtown adults had no time to make jaunts to other territories.

Meanwhile at Pitt, Ecco spent a busy day courting Morela multiple times on 25 June.

Morela and Ecco, 25 June 2020, 7:32am

Even if we didn’t know Dori’s real mate, this timing indicates Ecco has nothing to do with the Downtown nest.

So, Ecco isn’t two-timing. Frankly he’s having trouble being a successful one-timer.

My apologies for sending us all down this speculative rabbit hole. I should have brushed off Dori’s visit as curiosity on her part. I’ve seen other females visit the Pitt nest during turbulent times. Magnum visited twice in 2016 during Hope’s first turbulent year.

As much as I know peregrines I never learn that they’re surprising.

(photos from the National Aviary falconcam at Univ of Pittsburgh and Lori Maggio)