All posts by Kate St. John

Imprinting Error

In 2011 crane watchers in Homer, Alaska noticed that a single Canada goose was convinced he was a sandhill crane. How did this happen? And can it be undone?

As described by Encyclopedia Britannica, imprinting is a form of learning in which a very young animal fixes its attention on the first object it sees, hears, or is touched by and thereafter follows that object.

Imprinting is especially important for nidifugous birds — species that walk away from the nest shortly after hatching — because they must immediately follow their mother in order to survive. They imprint by sight and the lesson lasts a lifetime. If the first thing they see is their mother or another member of their own species, life is good. If not, they grow up believing they are another species and will never find a mate.

Imprinting happens at different times for different species so wildlife centers use surrogacy techniques, described here at the Wildlife Center of Virginia, to insure that baby birds don’t imprint on humans. If they do they cannot be released in the wild.

Human imprinting is well known among cranes so caregivers in the Whooping Crane Recovery Program dress in crane costumes when in sight of the young birds.

Whooping crane costume worn by biologists (photo by Steve Hillebrand, USFWS)

Birds use filial imprinting but there are other forms. Studies have shown that we humans prefer the first computer software we use and then compare all new software to that first and favorite app. It’s a form of imprinting called Baby Duck Syndrome. “I don’t like this; it doesn’t work like Microsoft Word.” Quack! Quack!

As for the Canada goose in the video, observers speculated that the bird’s mother laid his egg in sandhill crane nest. When he hatched he saw a sandhill crane and imprinted on the wrong species. He’s the victim of an imprinting error.

(video by Nina Faust on YouTube. photos from Wikimedia Commons; click on the captions to see the original)

Watch a Nest in Bermuda

Screenshot from the Bermuda cahow cam at Cornell Lab

Nesting season began last month for this pair of Bermuda cahows when the female laid her single egg on 10 January 2019. The parents are now taking turns at incubation duty. They expect the egg to hatch in early March.

Watch them in their nest burrow at Cornell Lab’s Bermuda Cahow Cam.

And for a preview of things to come, here’s a video of last year’s activity.

(screenshot from the Bermuda cahow cam and a video of 2018 Bermuda cahow highlights, both from Cornell Lab of Ornithology)

Zooming Past Jupiter

What is it like to get close to Jupiter?

In this NASA video a robotic spacecraft called Juno makes its sixteenth fly-by (Perijove) since arriving in mid-2016. Its closest approach is almost dizzying. I feel better when the spacecraft zooms away and we see the swirling clouds.

Did you notice that Jupiter is on the sound track, too? The fourth movement of Gustav Holst’s The Planets is called Jupiter, The Bringer of Jollity. Listen to the entire majestic movement here.

This video was featured on NASA’s Astronomy Picture of the Day on 5 February 2019.

Pittsburgh Parks Listening Tour, Now Through April

Schenley Park, Panther Hollow lake, April 2017 (photo by Kate St. John)

If you live in the City of Pittsburgh and visit our parks you’ll want to participate in this survey, available now through April 2019.

Pittsburgh has 165 parks sprinkled throughout our neighborhoods from small playgrounds to regional parks — Schenley, Frick, Riverview, Highland and the future Hays Woods. The City’s goal is to have well maintained parks within a 10-minute walk of every resident.

Perhaps you’ve noticed that infrastructure is crumbling in many of them. The park system gets big donations for capital improvements (bricks & mortar) but not for maintenance, so we have new buildings like the Frick Environmental Center but deteriorating playgrounds, landscape and trails. How do we fix that inequity and how much will it cost?

The City of Pittsburgh and Pittsburgh Parks Conservancy have teamed up for the Parks Listening Tour, a citywide initiative to hear what neighbors love about our parks and what they would love to improve.

The Listening Tour includes meetings in every neighborhood and online tools. Attend a meeting to find out more or go online to view the presentation and take the survey. Click here for the schedule and online tools.

This is your chance to speak up for the parks. Your comments will shape their future.

(acknowledgements: text and tour logo from the Pittsburgh Parks Conservancy, photo of Schenley Park by Kate St. John)

Count Birds, Feb 15-18

One week from today — February 15-18 — the Great Backyard Bird Count will take a real-time snapshot of birds around the world. You can help.

Since 1998 the Great Backyard Bird Count (GBBC) has enlisted volunteers like us to count the birds we see for four days in mid-February.  Last year our worldwide effort counted 6,459 species and nearly 29 million birds!

Everything you need to know is at including this slideshow that explains how to do it. It’s as easy at 1-2-3.

  1. Register for an eBird or GBBC account if you don’t already have one. (GBBC uses eBird so you don’t need both.)
  2. Count birds for at least 15 minutes during the four-day period.  You can count in more than one place and longer than 15 mins if you wish. Keep track of the highest number of each species you see with a separate checklist for each new day, for each new location, or for the same location if you counted at a different time of day.
  3. Use your computer or the eBird mobile app to submit your observations.

If you love to take photographs submit your best shots to the GBBC photo contest. Click here for contest information.

You can count birds anywhere —  in your backyard, in a park, at the shore, or on a hike.  If the weather’s bad, stay indoors and count birds at your feeders.

On your mark… Get set… Go! February 15-18, 2019

(2019 poster from

Island Disappears In Rising Seas

Location of Dogger Bank (image from NASA via Wikimedia Commons)

Climate change is giving us extreme weather, melting glaciers and rising seas. It’s not the first time we humans lived through this but the last event was during the Stone Age and nobody wrote it down.

During the last Ice Age England was connected to Europe. As the glaciers receded people moved to the land between. Dogger Bank was the highest ground, about 100 feet above sea level.

100 feet sounds like a safe height, right? Nope. The glaciers kept melting. Dogger Bank disappeared 8,200 years ago.

Many islands face this fate in the 21st century including Tangier Island, Virginia (map below) and the island nations of Kiribati and the Maldives with 100,000 to 400,000 residents respectively.

Location of Tangier Island, Virginia, threatened by sea level rise, via Google maps
Sunset in the Maldives (photo from Wikimedia Commons)

Like Dogger Bank they’re going underwater. Read more in this vintage article about Dogger Bank In the Age of Rising Seas.

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

Peregrines Are Pairing Up

Peregrine pair at Cuyahoga Valley National Park, Nov 2018 (photo by Chad+Chris Saladin)

While we wait for the first egg at the Hays bald eagle nest, other raptors are getting into a breeding mood. Red-tailed hawks are soaring together. Peregrines are pairing up.

Pittsburgh’s peregrines won’t lay eggs until March but they’re already busy claiming territory, attracting mates, and courting. You’ll see them perching near each other in prominent locations, engaging in spectacular courtship flights, the male bringing food for his lady, and the pair bowing at the nest (only visible on a falconcam). This activity makes February and March my favorite months for peregrine watching.

Claiming territory is a blatant activity but the peregrine’s first egg date is nearly impossible to determine without a falconcam. Unlike bald eagles, peregrines nest on inaccessible ledges and don’t begin incubation until the next to last egg has been laid. The only sign that they’re incubating is that you see only one peregrine for more than a month; the other one’s on the nest.

Thanks to the falconcam at the University of Pittsburgh’s Cathedral of Learning we know that the resident female, Hope, lays her first egg between March 6 and 15. She and her mate Terzo are already courting as seen on Monday Feb 4. Watch them on the National Aviary’s streaming falconcam.

Hope and Terzo bow at the Cathedral of Learning nest, 4 Feb 2019 (photo from the National Aviary falconcam)

Visit the sites below to see Pittsburgh’s peregrines in person. Every site (except Pitt) needs additional observers and every observation is useful. You can help! Leave a comment if you want to join.

RegionNesting Territory
City of PittsburghCathedral of Learning
Downtown Pittsburgh
Monongahela WatershedWestinghouse Bridge
Elizabeth Bridge
Ohio River ValleyMcKees Rocks Bridge
Neville Island I-79 Bridge
Monaca/Beaver bridges
Allegheny River ValleyHarmar: Hulton Bridge
Tarentum Bridge
Kittanning: Graff Bridge

For additional information and resources see my Peregrine FAQs page.

(photo by Chad+Chris Saladin of the peregrine pair at Cuyahoga Valley National Park, Ohio. Yes, they perch in trees there.)

How To Tell A Raven From A Crow

Common raven (photo by Marge Van Tassel)

Ravens (Corvus corax) are becoming more common in Pittsburgh but you might not notice them because they resemble crows (Corvus brachyrhynchos).

In the past month I’ve looked closely at pairs and solo crows. Sometimes I discover they’re ravens. Here are tips for telling them apart, listed from easiest to hardest.

  • Tail shape: In flight ravens have wedge-shaped tails, crows have straight-across or curved-tip tails.
  • Sound: The raven’s call is a rough “Brock! Brock!” Crows say “Caw! Caw!” Ravens also say a lot of bizarre things.
  • Flight style: Ravens soar and sometimes tumble, crows flap. If you see a soaring corvid it’s a raven.
  • Social behavior: In Pittsburgh, ravens travel alone or in pairs, crows travel in big flocks or family groups of 3-4. (In Los Angeles there are flocks of ravens.)
  • Size (not always helpful): Ravens are larger, the size of a red-tailed hawk.
  • Silhouette: Because the raven’s tail is longer and wider, his head looks relatively small and pointy.
  • Beak: Ravens have big powerful beaks, crows do not.

These silhouettes illustrate two field marks. On the left, two crows have straight-across or curved tips on their tails. On the right, the solo raven has a wedge-shaped tail and his head looks relatively small and pointy.

Two American crows on the left, one raven on the right (photos by stonebird on Flickr and Shutterstock)

Sound is the best field mark if the birds are calling. This audio clip from Xeno Canto has a raven in the foreground (Brock! Brock!) and crows cawing in the background.

Raven calling, Crows in the background (recording made in Massachusetts by Will Sweet, Xeno Canto 453945)

Ravens also have an amazing vocal repertoire including these unusual sounds: The Bell call, a machine sound, a water drop, “taco taco” and much more.

Still stumped on how to tell the difference? Here are additional tips and a quiz from The Raven Diaries.

(photo credits: raven in flight by Marge Van Tassel. Comparison: two crows by stonebird on Flickr, raven silhouette from Shutterstock in 2010)

p.s. Click here for an audio treat that includes ravens calling in almost-human voices, recorded in the Adirondacks near Vermontville, NY.

Waiting For The First Eagle Egg

Hays bald eagle pair, 3 Feb 2019 (photo by Dan Dasynich)

Bald eagle nesting season has come to western Pennsylvania. Our favorite pair at Hays Woods finished their new nest in early winter and are spending lots of time together. The Hays eaglecam is up and running. Everyone’s ready for eggs.

Yesterday Dan Dasynich spent time on the Three Rivers Heritage Trail taking photos of the eagles. He captured this one just after they had a mating session. Then the male flew off downriver.

Because the Hays pair has been on camera for five years we have details of their nesting history. From 2014 through 2018 the female laid her first egg between February 10 and February 19.

Her earliest date was in an unusual year. In 2017 she laid her first egg on February 10 but the nest tree blew down on February 12 so the pair built another nest very quickly. She laid her first egg in the replacement nest on 20 Feb 2017.

If history is any guide, the first egg is one to two weeks away. Meanwhile the Hays eagles are putting finishing touches on the nest, the male is bringing food for his lady, and they mate many times.

When will the first egg arrive? Watch for it on Audubon Society of Western PA’s camera at Hays, PA Bald Eagle Nest

Eagle eggs are coming soon.

(photo by Dan Dasynich)

UPDATE: First egg was laid on Tuesday 12 Feb 2019 at 6:45pm

First egg at Hays bald eagle nest, 12 Feb 2019, 6:45pm (photo from the Hays eaglecam at ASWP)

Baby Eagle Owl At The Aviary

Baby Eurasian eagle owl at the National Aviary, 18 Jan 2019 (photo courtesy National Aviary)

Super Bowl Sunday is “Superb Owl Sunday”

Hatched at the National Aviary on 12 January 2019, this Eurasian eagle owl chick is growing up fast. In the photo above he’s six days old.

His parents are education birds at the National Aviary and he(*) will be, too. To prepare him for this role he’s being hand-raised with lots of love and attention and began close encounters with a few Aviary visitors at the tender age of 17 days.

By the time he’s four weeks old he’ll look like this owlet — one of his siblings from 2013.

Baby Eurasian Eagle Owl at the National Aviary, April 2013 (photo courtesy of the National Aviary)

When he grows up he’ll look like his parents. By then he’ll be a very big bird.

Eurasian Eagle Owl adult at the National Aviary (photo courtesy National Aviary)

Eurasian eagle owls (Bubo bubo) are virtually the world’s largest owl. Native to Europe and Asia, they can weigh up to 10 pounds with a wingspan more than six feet long. That’s 1.5 times larger than North America’s great horned owl. You can tell the difference between the two species — even in photographs — when they open their eyes. Adult Eurasian eagle owls have orange eyes. Great horned owls have yellow eyes.

Watch the owlet grow up at the National Aviary‘s Avian Care Center window or schedule a close encounter to meet him in person. Participants can touch the chick’s downy feathers, take photos, and interact with him under the supervision of National Aviary animal care experts. The number of encounters is limited and available for only a few weeks. Click here to sign up for an owlet encounter.

(photos courtesy of the National Aviary)

(*) I said “he” in this article but we really don’t the owlet’s sex without a DNA test!