Category Archives: Bird Behavior

Evacuate!

Southeast U.S. radar image, 15 Sept 2018, 5:08 EDT (image from National Weather Service)

Birds can sense when bad weather is coming. If it’s going to be dangerous and they have some lead time they get out of the way.  Hurricane Florence gave them plenty of time to prepare.

Weather radar shows us where it’s raining by detecting objects in the sky.  When masses of birds are on the move they show up on radar, though less intense than steady rain. Flocks of birds look green on radar and are only detected when near radar stations.  Since most birds migrate at night, that’s when to watch.

This radar image from 5:08am on Saturday September 15 shows the rain bands of Hurricane Florence swirling over the Carolinas. Notice that there’s no rain for miles surrounding the circle of the storm but there are intense green blobs southwest of Florence over the Florida panhandle.

Thousands of birds! They’ve heard the news and they’re leaving the area.  Evacuate!

p.s. Read more about birds on radar here and an article about birds escaping storms by flying hundreds of miles out of their way 

(image from National Weather Service)

Too Hot!

Great blue heron gular fluttering (photo from Wikimedia Commons)

With highs over 90 degrees and dewpoints at 70 it’s just too hot in Pittsburgh! We’re coping by staying indoors with air conditioning but what do birds do?

This great blue heron in Florida is using at least five techniques for staying cool. 

  • He’s gular fluttering which looks like panting.  Herons are one of several kinds of birds that can vibrate the skin, muscles and bones of their throats to increase heat loss. See more here
  • He has wet belly feathers.  Aaahhhhh!
  • He’s exposing the skin on his legs to cool them off.
  • He’s holding his wings slightly open to cool off his “armpits” and
  • He’s standing in the shade.

He could also try soaring where it’s cooler or sleeking his body feathers to squeeze heat out of his downy undercoat.  (Maybe he’s doing the squeeze thing. I can’t tell.)

That’s all that most birds can do to cope with heat, but the ostrich has an additional amazing solution. 

When a body is warmer than the surrounding air it loses heat.  We know this happens in winter but the ostrich makes it work in summer.  He raises his body temperature in a controlled fashion —  4.2o C (7.5o F) during the day — so that his body loses heat to the outdoors. 

Male ostrich, bare legs (photo from Wikimedia Commons)

For us, it would be like having a fever on a hot day. 

No thanks! It’s too hot already!

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

Crows At Work

Carrion crow picking up (photo from Wikimedia Commons)

On Labor Day, let’s watch some crows at work.

At a theme park in France trained crows are showing humans not to litter.  At least that’s one of the ideas behind teaching crows to pick up cigarette butts at Puy du Fou.

The historical theme park in Les Epresses, France has falconers who conduct live bird shows featuring falcons, owls, vultures and crows.  One day one of the crows picked up litter instead of the prop he was cued for.  The crowd was impressed.

Management was impressed too so now they have six trained crows who pick up cigarette butts in exchange for a treat.

The crows love their job. Their trainer says they’d do it all day if you let them.  Click here or on the image below to watch the crows in action.

Screenshot from AFP video

Read more in this article from Popular Science.

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

Rescuing Baby Puffins

Earlier this month we learned that mayflies have a fatal attraction to outdoor lights.  So do fledgling puffins!

In August and September young puffins, called pufflings, make their first flight from their nesting islands in Newfoundland.  Guided by the light of the moon they head for the open ocean.  Unfortunately, when it’s foggy or moonless they’re confused by outdoor lights and head inland where they become stranded and die.

Years ago Juergen and Elfie Schau of Germany noticed stranded pufflings near their summer home at Witless Bay, Newfoundland so they rescued them and returned them to the sea.  Soon their neighbors joined them and in 2011 the project grew into the Canadian Parks and Wilderness Society’s (CPAWS) annual Puffin and Petrel Patrol.

Travelers from around the world come to Witless Bay in late summer to help rescue baby puffins. The stranded birds are captured in small nets, placed in carriers, and released in the morning when the birds can see where they need to go — out to sea.

The video above shows a typical puffling rescue day at Witless Bay, NL. Look closely and you’ll see that this is the same beach where I saw the capelin rolling in July!  Newfoundland is awesome!!

Read more about the Puffin and Petrel Patrol in this article from Mother Nature Network. Thanks to John English for sharing it.

(video by CBC News: The National on YouTube)

I Don’t Care How Big You Are!

Red-winged blackbird attacks bald eagle, May 2018 (photo by Steve Gosser)
Red-winged blackbird attacks bald eagle, May 2018 (photo by Steve Gosser)

Though red-winged blackbirds don’t have sharp beaks and talons, they’re fearless when they’re nesting.  It doesn’t matter how big the other bird is.  They chase it away.

Back in May, Steve Gosser saw a red-winged blackbird attack a bald eagle.

In 2011 Steve Valasek saw one attack the largest bird on earth.  On Throw Back Thursday, see what happened in this vintage article:  I Don’t Care How Big You Are!

 

(photo of red-winged blackbird attacking a bald eagle by Steve Gosser)

Eagle Productivity Drops For a Good Reason

Juvenile bald eagle at Hays, H8, 23 June 2018 (photo by Dana Nesiti)
Juvenile bald eagle at Hays, H8, 23 June 2018 (photo by Dana Nesiti)

Bald eagles have made an amazing comeback since the days of DDT.  From less than 900 birds nationwide in the early 1960s to more than 20,000 in the U.S. in 2007, their population more than doubled in Pennsylvania in the last 10 years.

At some point the number of nesting bald eagles will reach Pennsylvania’s carrying capacity.  What happens then?  How do bald eagles respond to match available food and nest sites?   We can look to Virginia for the answer.

Since 1964 the Center for Conservation Biology in Williamsburg has monitored and mapped bald eagle nests in the James River watershed.  Every year they do a flyover of the entire area to count both nests and chicks. Their eagle population grew from none in 1976 to a record 289 nests in 2018.  Meanwhile the number of chicks per nest — called “productivity” — rose sharply in the early years of recovery and now is dropping.  CCB announced this trend in two articles:

To see how this works, I have made a slideshow of two graphs from the Center for Conservation Biology’s article.  The bar chart is the count of nesting pairs, 0 to 289.  The line chart, the arc, is the average number of chicks per nest, 0 to 1.6.

As you can see, the number of nesting pairs continues to increase while the number of chicks per nest moves down.

CCB reports that in 2018 the number of chicks reached 1.09 and adds, “The two opposing trends appear to continue the population’s path to stability.”

“Productivity decline” sounds bad but it’s actually good news.  Breeding eagles respond naturally to accommodate lots of adults in the habitat.

So what does this mean for Pennsylvania’s bald eagles?

If the James River experience applies here, we’ll still see an increasing number of bald eagle nests that will eventually average one eaglet per nest.  We know bald eagles can produce more if they need to.  The good news is, they don’t need to.

 

p.s. See how rapidly the James River nest count grew!   Click here for CCB’s maps of the James River bald eagle population, 1990-2017.

(photo of juvenile bald eagle H8 at the Hays nest site by Dana Nesiti. Slideshow of two graphs from the Center for Conservation Biology article Eagle Productivity Continues to Slide.)

Merlin Attack! Raven or Crow?

Merlin attacks a big black corvid at Renews, NL (photo by Trina Anderson)
Merlin attacks a raven at Renews, NL, 10 July 2018 (photo by Trina Anderson)

Last week in Newfoundland our birding tour witnessed an amazing bird interaction when a merlin attacked a big black corvid in the air.  It happened so fast that we had to think hard about the birds’ identities.

Yes the attacker was a merlin —  a small, streaky dark, very fast falcon that made this sound as it attacked. (Xeno-canto XC332445: alarm calls of merlin pair recorded by Pritam Baruah in Churchill, MB, August 2016)

But was the big black bird a crow or a raven?

Fellow traveler Trina Anderson captured the action with her camera. Before we saw her photos we could only identify the corvid by size and behavior.  We decided “raven” based on the relative size of the two birds and the behavior of the raven.

  • Merlins are 2/3 the size of a crow but less than half the size of a raven.  Overhead the merlin was tiny compared to the bird it attacked, so it had to be a raven. Trina’s photos show the size difference.
  • The black bird barely flapped during the interaction and it flipped upside down in flight (see the last photo). Crows flap hard when they’re under attack and they don’t fly upside down.
  • During the fight it was hard to see the diagnostic field mark — the tail — but Trina’s next photo shows the corvid has a wedge-shaped tail. That means “raven.”
Merlin attacks a corvid, Renews, NL, 10 July 2018 (photo by Trina Anderson)
Merlin attacks raven, Renews, NL, 10 July 2018 (photo by Trina Anderson)
Merlin attack! Raven flips upside down, Renews, NL, 10 July 2010 (photo by Trina Anderson)
Merlin attacks! Raven flips upside down, Renews, NL, 10 July 2010 (photo by Trina Anderson)

It’s hard to tell ravens from crows unless you have some practice.  Get tips on how to tell them apart in this 3 minute video from The Raven Diaries: Ravens vs Crows, they’re different!

 

(photos by Trina Anderson. See more of photos of our Newfoundland trip in her Flickr album.)

Do You Like Blue Jays?

Do you like blue jays?

I do, but I often encounter people who don’t.

Everyone agrees that blue jays are pretty but a lot of people don’t like their manner.  When a blue jay enters the room, he takes up a lot of space.

Lesley The Bird Nerd changed her mind about blue jays as she got to know them in her backyard in Canada.  She learned about their intelligence and faithfulness, and how to identify them as individuals.

Watch her video to see what’s cool about blue jays.  Lesley saves the best for last.

 

p.s. Blue jay faces are unique. Here’s Lesley’s video on how she identifies them as individuals.

(video by Lesley The Bird Nerd. Subscribe to her videos here.)

Thank You For Eating Them

Hays bald eagle female returns with a rat to feed her fledgling, H8, 23 June 2018 (photo by Dana Nesiti)
Hays bald eagle female returns with a rat to feed her fledgling, H8, 23 June 2018 (photo by Dana Nesiti)

We often complain when birds of prey eat “our” songbirds, rabbits, chipmunks and squirrels but there’s one prey item that no one quarrels about.

Last weekend Dana Nesiti posted a photo series at Eagles of Hays PA:  The mother bald eagle brought food for her fledgling, H8, who quickly crowded her and grabbed for it. The prey was nearly lost in the scuffle.  (click here for the photo album)

What did she bring him for dinner?  A rat!

Thank goodness birds of prey are eating rats. I’ve seen red-tailed hawks eat them, too.

On Throw Back Thursday, read about a red-tail that’s Performing a Public Service.

 

p.s. If you see a hawk eating a rat, it’s not a peregrine falcon.  Peregrines catch their prey in flight. Rats don’t fly.  😮

(photos by Dana Nesiti)

Uses Tools

When I was in grade school we learned that using tools was one thing that made humans different from animals.  This false distinction ended years later when we (officially) noticed that monkeys and parrots use tools.

So do green herons.

Rather than hoping a fish will come within reach, green herons will use live bait or lures to attract them.  Live bait works best but bread is easier to find where humans have thrown it to the ducks.

Watch this green heron use a slice of bread to lure a fish.

Why does he toss and retrieve the bread over and over?  He has a particular fish in mind.  Wait and see.

 

(video from YouTube)