Mar 12 2015

TBT: Conspicuous

Red-tailed hawk soaring (photo by Cris Hamilton)

Throw Back Thursday (TBT):

Red-tailed hawks are conspicuous now as they soar to claim territory and court their mates.

Click here for a timely article from 2009 that describes what they’re doing.

Watch for the male’s Sky Dance.

 

(photo of a soaring red-tailed hawk by Cris Hamilton)

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Mar 11 2015

Bobble Buffleheads

Spring is finally here and the early birds are on their way north.  Among them are bufflehead ducks whose body shape and courtship behavior would earn them a different name if they needed one today.

Buffleheads (Bucephala albeola) are small black and white ducks that nest in tree cavities from western Quebec to Alaska.  Males are striking black and white, females mostly black, and they’re named buffleheads — “buffalo heads” — because the male’s head looks large and out of scale for his size.

Watch the video above and you’ll see three males “use their heads” to impress the lone female.  They are bobbing like crazy!  Apparently, the bigger the bob the better.

There’s even more going on.  Here’s a list of courtship displays quoted from Cornell’s Birds of North America Online.

  • Head-bobbing is the most common.
  • Fly-over and Land (not seen in the video):  The male flies over the female and lands close to her, skiing on water to show off his feet, raising his head feathers to show off his head.
  • Head-shake-forward:  After landing the male tosses his head forward and …
  • Wing-lift:  … and raises his wings high behind his head.
  • Leading and Following are done by established pairs.  “The male leads by swimming vigorously with the neck stretched upwards, sometimes pecking to the side, and the female usually responds by a Following Display, in which she swims or runs on the surface to catch up with the male, her neck extended, and vocalizes.”

So this lady has a mate (he’s Leading) but it doesn’t stop the other two guys from making a pass.  When one of them is particularly persistent she chases him away but he’s not convinced until her mate chases, too.

Buffleheads court while on migration so you’ll see this behavior on nearby lakes and rivers this month.

Do they make you think of buffaloes when you see their heads?

Nope.  If we had to name them today, we’d call them bobbleheads.

 

(video by winterwren3 on YouTube)

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Mar 10 2015

Ladies Make Do In A Pinch

Laysan albatross adults dance (photo from Wikimedia Commons)

Out in the Pacific there are more female Laysan albatrosses than males.  The males will mate with the extra females but it takes two parents to raise the chick.  A single mom can’t raise her chick alone.  What’s a girl to do?

A long term study of Laysan albatrosses, published in 2008, shows that the extra females pair up in reciprocity agreements.

Albatrosses are such big birds that it takes a whole year for their solo chicks to mature and fledge.  Rearing the chick takes so long and is so labor intensive that female albatrosses lay one egg every other year.

Without a mate to help with nest duty the chick will die.  Researchers on Oahu, where the Laysan albatross population is 59% female, discovered that unrelated females on opposite fertility cycles pair up and raise each others’ chicks.  At the start, only one of them lays an egg and the pair incubates and raises the chick together.  When it’s egg-laying time again, the other female takes her turn.

Though their nesting success is lower than for male-female pairs, it works well enough that these girlfriends stay together for many years.

Ladies make do in a pinch.

Read more here at Science Daily.

 

p.s. Watch a Laysan albatross nestcam in Kauai, Hawaii on Cornell Lab’s website.  The chick is huge!

(photo from Wikimedia Commons. Click the image to see the original)

4 responses so far

Mar 09 2015

Miniature Mesa

Published by under Quiz,Schenley Park

Miniature mesa A (photo by Kate St. John)

Here’s a Monday quiz to exercise your brain.

I found this miniature mesa in Schenley Park last week.

Do you know what it is?

Which side is up?

Miniature mesa B (photo by Kate St. John)

Here’s a more complex formation.

A unch of mini-mesas in winter (photo by Kate St. John)

So … what they are?

Leave a comment with your answer.

 

UPDATE:  I’ve posted the answer in the Comments.

(photos by Kate St. John)

5 responses so far

Mar 08 2015

It Was Pretty

Snowy view on 5 March 2015 (photo by John English)

Snowy view on 5 March 2015 (photo by John English)

Yes, last Thursday’s snow was pretty.

It coated the trees like a winter wonderland outside John English’s apartment window (above).

And I found close up beauty in Schenley Park.

Snow in Schenley Park, 5 Mar 2015 (photo by Kate St. John)

One leaf  (photo by Kate St. John)

 

Snow on Queen Anne's lace, 5 March 2015 (photo by Kate St. John)

Queen Anne’s lace (photo by Kate St. John)

 

In December I’d be thrilled by snow but within a few hours I was heartily tired of this beautiful event.

Fortunately it will go away this week.

 

(photo of snowy hillside by John English.  Closeups by Kate St. John)

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Mar 07 2015

Woo Hoo!

Dori and Louie court at the Gulf Tower nest, 6 Mar2015 (photo from the National Aviary falconcam at Gulf Tower)

Yesterday I fretted that Dori and Louie might not nest at the Gulf Tower because they hadn’t been seen there since February 20. I was so concerned that they might be using their old nest site on 3rd Avenue that I went over there at 5:00pm to find them. But no peregrines.

This morning I pulled two motion detection images from the Gulfcam and found out why they weren’t at 3rd Ave.

Here they are after everyone left for the weekend!

Just after 5:50 pm Friday, Louie was moving so fast he was a blur.  :)

Louie lifts off from the nestbox at Gulf Tower (photo from the National Aviary falconcam at Gulf Tower)

Woo hoo!

 

(photos from the National Aviary falconcam at the Gulf Tower, Pittsburgh)

11 responses so far

Mar 06 2015

What’s Up With These Peregrines?

Magnum perched at Neville Island while her mate flies by, 28 Feb 2015 (photo by Anne Marie Bosnyak)

February and March are great times to watch peregrine courtship in Pittsburgh.  Unfortunately our two sites with webcams — Pitt and the Gulf Tower — have little or no courtship activity.  What’s up with these peregrines?

Nearly every day I visit the University of Pittsburgh to check on Dorothy and E2.  They’re usually perched on the Cathedral of Learning but they don’t make courtship flights like they did in the old days.  This is probably because, at age 16, Dorothy isn’t interested anymore.  She seems to be in “hen-o-pause” since her egg bound episode last spring.

Sadly this means the pair is rarely on the webcam.  Twice last week E2 tried to lure Dorothy to the nest but she visited only once.  This is in stark contrast to her prior habit of sitting at the nest for hours and courting several times a day, even in February snow.  I don’t expect any peregrine chicks while Dorothy is in charge.

At Gulf there’s a beautiful new HD webcam — and no peregrines!  They visited the nest on February 7 and 20 but Ann Hohn at Make-A-Wish confirms what the camera says:  No peregrines have been there for two weeks.  This is highly unusual if they intend to nest at Gulf.  I wondered if they’d gone back to their old 2012-2013 nest site near Point Park University so I checked it last Saturday.  No peregrines there.  No peregrines anywhere Downtown.  What’s up?  I don’t know.

The bright spots have been the bridges.

I’ve only been to the Westinghouse Bridge once this year, but I saw a peregrine perched on it when I drove by on February 22.  At Tarentum I saw both peregrines in courtship flight on nestbox-installation day.  And at the Neville Island I-79 Bridge, Anne Marie Bosnyak saw the peregrines court and mate last Saturday.  They even stayed long enough for Anne Marie to go home for her camera and take these beautiful photos of Magnum and her mate.  Love is in the air at Neville.

Magnum at Neville Island, 28 Feb 2015 (photo by Anne Marie Bosnyak)

So far there are no sightings at the Monaca-East Rochester Bridge, the McKees Rocks Bridge, and the Greentree water tower — though that doesn’t mean there aren’t peregrines.

If you have any news, post a comment to let us know … What’s up with these peregrines?

 

(photos of Magnum and her mate by Anne Marie Bosnyak)

p.s. Folks in Johnstown are hoping their lone male peregrine on the First National Bank Building attracts a mate soon.

8 responses so far

Mar 05 2015

Cover Your Ears

Published by under Mammals

Opossum in winter (photo by Cris Hamilton)

After Tuesday night’s high of 49oF we’re headed for 1oF tonight.  Everything that lives outdoors is in for a huge surprise.  Opossums, in particular, should watch out.

Opossums’ thin ears and naked tails are prone to frostbite.  Though normally nocturnal, they come out during the day when they’re hungry.  That’s how Cris Hamilton photographed this one at her bird feeders in early 2011.

And yes, her backyard possum had a hard winter that year.  His ears are pink because they’re frostbitten.

Opossums! Cover your ears tonight … or stay indoors.

 

(photo by Cris Hamilton)

 

 

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Mar 04 2015

Selective Attention In Chickens

Chicken (photo by Luis Miguel Bugallo Sánchez via Wikimedia Commons)

I love the title but … What the heck is Selective Attention and who cares about it in chickens?   (Don’t worry, there’s fun at the end.)

Selective attention — the ability to focus in the midst of distractions — is something we humans do well.  For instance, we can listen to one person in a crowded noisy room and focus completely on what they’re saying, tuning out everything else.  This is useful!

Selective attention has been studied extensively in primates.  Do birds possess this skill?

Anecdotally, I’d say “Yes.”  I’ve watched red-tailed hawks keenly focused while hunting next to busy roads.  They tune out all the traffic and successfully catch their prey.  Unfortunately some are way too good at ignoring traffic and are struck and killed by vehicles.

No one had proven selective attention in birds until researchers at Stanford University’s School of Medicine gave chickens quick visual cues to see if they would peck outside the (virtual) box.  Published in Proceedings of the National Academy of Sciences in 2014, “The results show that chickens shift spatial attention rapidly and dynamically, following principles of stimulus selection that closely parallel those documented in primates.”

Watch the chicken peck the X in the middle. Then a quick flash of light attracts his attention.  Birds and primates both inherited this cognitive skill.

And now a quiz for you:  Remember how I said red-tailed hawks are sometimes hit by cars because they’re focusing so much?  Watch this video to test your own selective attention.

… and you’ll understand the red-tail’s problem.

 

(chicken photo by Luis Miguel Bugallo Sánchez from Wikimedia Commons.  Click on the image to see the original.)

10 responses so far

Mar 03 2015

A Mimic On Two Levels

Published by under Mammals

Margay cat or "tree ocelot" (photo from iStockphoto/Jeff Grabert via Science Daily)

One glance tells you this wild cat’s fur mimics his dappled forest habitat.  Amazingly, he can mimic on another level, too.

The margay (Leopardus wiedii) is a nocturnal feline of Central and South America that looks like a small ocelot.  Longer and lighter weight than a pampered house cat, he weighs 5.7-8.8 pounds and is 32-51 inches long (including his long tail!).

The margay lives in trees in the tropical forest and rarely comes to the ground because he doesn’t need to.  He’s so well adapted to climbing that his ankles rotate 180 degrees so he can walk down trees head first.  He can also leap 12 feet straight up to capture small mammals, birds, lizards and tree frogs.

In Brazil one mammal on the margay’s menu is the pied tamarin (Saguinus bicolor), a small primate the size of a squirrel.

Pied tamarin (photo by Whaldener Endo via Wikimedia Commons)

Native Amazonians have long known that the margay can mimic the sound of this monkey, but it wasn’t recently that the rest of the world found out.

In 2005 researchers watched a group of eight pied tamarins feeding high in a ficus tree when a margay, hidden in dense liana vines, tried to lure them by mimicking the call of a tamarin pup. A tamarin “sentinel” climbed down to investigate the noise, then started to warn the rest of the group, but four other tamarins were so confounded by the baby tamarin sound that they too climbed down to see.  At that moment, the margay emerged from the foliage, walking head first down the trunk, and jumped toward the monkeys. Realizing the ruse, the sentinel screamed an alarm and all the tamarins fled. (*)

The Wildlife Conservation Society reported this incident in 2010, the first recorded instance of a wild cat species in the Americas mimicking the calls of its prey.

Pied tamarins are endangered and the margay is “near threatened.”  Large primates (humans) have killed the margay for its fur and the pied tamarin for food.  We’re lucky to have heard of this mimickry trick before it disappeared.

Read more about it here in Science Daily.

 

(Margay photo from iStockphoto/Jeff Grabert via Science Daily. Pied tamarin photo from Wikimedia Commons/Whaldener Endo, Creative Commons license. Click on the images to see their originals.)

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