Archive for the 'Songbirds' Category

Jan 13 2014

Melancholy Tyrant

Published by under Songbirds

Tropical kingbird (photo by barloventomagico, Creative Commons license via Flickr)

Continuing my tropical theme…

The tropical kingbird seems rare to us because his range barely touches southern Arizona and the lower Rio Grande valley, but he’s a very common bird in Central and South America and is often seen near humans because he likes what we do to the landscape — especially our wires.

I became interested in him when I learned his scientific name: Tyrannus melancholicus.  It means “melancholy tyrant.”  Why was he named this way?

Members of the Tyrannus genus are “tyrant” flycatchers because they fearlessly defend their territory, nest and young against much larger predators.  Below, a tropical kingbird attacks a zone-tailed hawk.  Our Tyrannus, the eastern kingbird, does the same to hawks in Pennsylvania.

Tropical kingbird attackes a zone-tailed hawk (photo by barloventomagico, Creative Commons license via Flickr)

Melancholicus, meaning melancholy, is not an obvious choice for such an active bird.  Mourning doves are named for their sad song so I listened to the tropical kingbird’s song in case that’s what gave him his name. Click here to hear.

It doesn’t sound sad to me, but perhaps he’s so-named because he sings this tune in the dark before dawn and stops when the sun rises.

I don’t know…  Do you?

 

(photos of tropical kingbirds in Barlovento, north-central Venezuela, by barloventomagico, Creative Commons license via Flickr) 

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Jan 11 2014

No Snow

Snow buntings, Crawford County, Jan 2014 (photo by Shawn Collins)

Can you believe how warm it is today?

Shawn Collins found these snow buntings in Crawford County a week ago when the snow was melting.  Two days later we were in the sub-zero polar vortex.  Now it’s 60 degrees warmer and the snow is gone.

It’s a good thing snow buntings are white, brown and black. They’re camouflaged even when there’s no snow.

(photo by Shawn Collins)

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Jan 04 2014

At The Top Of The Mountain

Black rosy-finch (photo by Steve Valasek)

Here’s a bird I hope to see some day … but I’ll have to go out of my way to find it.

The black rosy-finch (Leucosticte atrata) is an alpine bird from the American West that spends all his life at high elevation.  In the summer he nests on cliffs above the treeline in the Rockies.  In the winter he moves to lower mountaintops.

Steve Valasek photographed this one at a feeder at Sandia Crest, New Mexico … at the top of the mountain.

 

(photo by Steve Valasek)

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Dec 06 2013

Bird Equivalents

Tufted titmouse, Great tit (photos from Wikimedia Commons)

Here’s an interesting thought: Around the world there are birds with similar habitat and food requirements that are ecological equivalents to each other.  Though they live on different continents they occupy similar niches.  Sometimes they even look alike.

I was intrigued by this when I found a graphic on page 630 of Ornithology by Frank B. Gill showing three sets of equivalent birds from North America and Europe.  Here they are:

Set #1.  The tufted titmouse in North America (at left above) is an ecological equivalent to the great tit in Europe (at right).

All About Birds says the tufted titmouse prefers “eastern woodlands below 2,000 feet elevation, including deciduous and evergreen forests. Tufted titmice are also common visitors at feeders and can be found in backyards, parks, and orchards.”

Europe’s great tit prefers similar habitat.  I wish our titmouse was as colorful.

 

Set #2.  Our black-capped chickadee (at left below) is equivalent to Europe’s willow tit (at right).

Again according to All About Birds, “Black-capped chickadees may be found in any habitat that has trees or woody shrubs, from forests and woodlots to residential neighborhoods and parks, and sometimes weedy fields and cattail marshes. They frequently nest in birch or alder trees.”

In Europe, look for the willow tit in these habitats.

Black-capped chickadee, Willow tit (photos from Wikimedia Commons)

 

Set #3.  The chestnut-backed chickadee of the Pacific Northwest (at left below) is equivalent to the coal tit in Europe (at right).

All About Birds says, “Chestnut-backed chickadees are found in dense coniferous and mixed coniferous forests of the Pacific Coast. You can also find them in shrubs, trees, and parks of cities, towns, and suburbs.”

The coal tit has similar habitat requirements in Europe and fills a wider niche in Ireland where competing marsh, willow and crested tits aren’t present.

Chestnut-backed chickadee, Coal tit (photos from Wikimedia Commons)

 

There are many more ecologically equivalent species.  GrrlScientsist shows us Kenya’s ecological equivalent of the red-tailed hawk at this link.

Can you think of other bird equivalents?

 

(photos from Wikimedia Commons. Click on these links to see the originals: tufted titmouse, great tit, black-capped chickadee, willow tit, chestnut-backed chickadee, coal tit.
Today’s Tenth Page is inspired by page 630 of Ornithology by Frank B. Gill.
)

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Nov 12 2013

Sparrow Time

Published by under Migration,Songbirds

Fox sparrow and white-throated sparrow (photo by Steve Gosser)

It’s not news that migrating sparrows are back in town but it’s always news to see a fox sparrow in any setting.

Steve Gosser photographed this one (top) with another migrant, a white-throated sparrow, at Harrison Hills Park last week.

Some sparrows come to western Pennsylvania in the fall and stay all winter, including dark-eyed juncoes, American tree sparrows, and the white-throated sparrow shown above.

But fox sparrows are few and far between and right now they’re just passing through, headed for the southern U.S.

If you don’t see one before Thanksgiving you’ll probably have to wait until March to catch them on their return trip back north.

I’ve been looking, but so far no luck.

 

(photo by Steve Gosser)

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Oct 29 2013

More Males Than Females

Summer tanagers, male and female (photos from Wikimedia Commons)

Here’s an amazing fact: Among birds, and especially among declining species, there are more males than females.

It’s always easier to find male birds during breeding bird surveys.  They’re clothed in conspicuous colors and put on a big show, singing and displaying to claim territory and find a mate.  Females are hard to see because they don’t sing, are often cryptically colored, and are secretive around the nest.  Unfortunately it’s not just flashiness that makes males easier to count.  The males are saying “Notice me!” because there aren’t enough females to go around.

In 2007, after reviewing hundreds of scientific papers, ornithologist Dr. Paul Donald concluded that in the vast majority of bird species males outnumber females. This means we can’t extrapolate the size of a breeding population based on the number of males we count.

Why does this happen?  Dr. Donald explained, “It’s not that females are producing more sons than daughters, because at hatching the sex ratio is generally equal. The only possible explanation is that females do not live as long as males. As generations grow older, they become increasingly dominated by males as more females die off.”

Dr. Donald also found that the skewed sex ratio is even worse among endangered birds and at its worst among the rarest species.  He hypothesized this is due to predation of females while on the nest — the double whammy of killing current and future generations at the same time.

Summer tanagers gave me personal experience with this sex ratio phenomenon.

The City of Pittsburgh is outside the summer tanagers’ range so it was quite rare that I found a pair of summer tanagers breeding in Schenley Park in 2011.   I noticed them just after their nest failed (due to a predator) because the male was impossible to ignore.  He was so angry he was shouting at everyone.

He and his lady tried for a second nest but it was too late in the season and they dispersed without success.  The next spring he was back again and easy to see.  He called and displayed, sang and sang, but she never showed up.  He was alone and that made it much easier for everyone to find him.  In 2012 he never had a mate.

This year he didn’t show up at all.   I assume both he and his lady have died.

Fortunately summer tanagers have a very wide range and their population is doing well — they are listed as “Least Concern” —  but they illustrated Dr. Donald’s finding:  Among most bird species there are more males than females.

 

(photos of summer tanagers (male on left, female on right) from Wikimedia Commons)

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Oct 22 2013

Strong Opening

 

If you’ve ever had a pet starling, you know their beaks are very powerful when opening.  That’s because European starlings have the unusual characteristic that their jaws are strongest in reverse.

It’s a counter-intuitive trait.  Our jaws are strongest when we clamp down.  William Beecher discovered that starlings’ jaw muscles are at their best when they spring open and that their eyes automatically rotate forward for binocular vision as they open their beaks.  This gives them an excellent look at potential prey in the hole they’ve just probed open and probably contributes to their success in winter.

Even as pets, starlings can’t help but probe.  It’s in their blood.  HayleyM‘s pet starling, Lolly, opens her son Aidan’s mouth as a dentist might.  Notice that beak action!

Don’t try this at home!

 

Click here to view the original video and read in the comments how this orphaned starling became a pet.  Also read the important notes in the p.s. below.

(video on YouTube, uploaded January 2011 by HayleyM)

 

p.s. Important notes:

* In North America, European starlings are one of only two wild birds (the other being the house sparrow) that can be kept as pets without a permit.  Both species are listed as invasive.

* In addition to the possibility of people catching disease from birds, HayleyM added this note to the video: “After review by my good friends at Starling Talk (www.starlingtalk.net), I have found out that this is an ill advised practice. Apparently the bacteria in the human mouth can actually make a bird sick.”

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Oct 06 2013

This Is Exciting

Yellow-rumped warbler, October 2013 (photo by Shawn Collins)

They’re here!  The yellow-rumped warblers are back from Canada, on their way to the lower Ohio Valley, the southern U.S., and Central America for the winter.

Yesterday Karyn Delaney and her husband stopped counting at 100 when they found so many yellow-rumps on the Pine Tree Trail at Presque Isle State Park.  Shawn Collins snapped this one in Crawford County.

Like the first snowfall I’m excited to see my first big flock of yellow-rumped warblers in southwestern Pennsylvania.  I haven’t found a flock yet but I think I’ve heard one bird — just one — at Schenley Park.

Unfortunately, just like snow I soon tire of them.  I remember at Magee Marsh last May when my first reaction to seeing yellow-rumped warblers was “Wow!” and within an hour it was “Darn!  Another yellow-rump.”  Their abundance becomes boring.

But I haven’t seen them yet, so for the moment this bird is exciting.

 

(photo by Shawn Collins)

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Oct 02 2013

The Most Pugnacious Woodpecker

Juvenile red-headed woodpecker attacks an adult (photo by Chris Saladin)

Watch out!

Last week Chris Saladin captured these action shots of two red-headed woodpeckers in a protracted fight at Sandy Ridge Reservation.  The immature woodpecker, still clad in gray, seems to have the upper hand.  What’s the deal here?  Why are they fighting?

All woodpeckers chase to maintain their territories but red-headed woodpeckers take fighting to an extreme.  During the breeding season they’re aggressive to everyone, especially the cavity-nesters.  They persecute northern flickers, red-bellied and downy woodpeckers.  If a starling dares to take a red-headed’s nest hole the woodpecker fights — and wins.  Even the pileated woodpecker defers to this bird.

Red-headed woodpeckers are especially aggressive toward each other and are solitary in winter because they fight so much.  Each one establishes a winter territory where he gathers and stores acorns for his personal use.  All other red-heads — male, female and immature — must stay away!

Perhaps the immature showed up on migration and is hoping to claim the Sandy Ridge wetland.  The adult is having none of it!

Above, he makes the bark fly as he bounces off the dead tree.  Below, he’s quick to get out of the way as the immature zooms in!

Juvenile red-headed woodpecker chases adult (photo by Chris Saladin)

And here they’re airborne in foot-to-foot combat!

Juvenile and adult Red-headed woodpeckers fighting (photo by Chris Saladin)

Apparently they can’t stand the sight of each other.

Will they ever stop?  Finally the immature pauses so we can see him at rest.

Juvenile red-headed woodpecker (photo by Chris Saladin)

A most pugnacious species!

 

(photos by Chris Saladin)

p.s. Click here to see what an adult red-headed woodpecker looks like when he’s not in battle.

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Oct 01 2013

Starling Story Problem

European starlings (photo by Bobby Greene)

When I was in grade school I hated Story Problems in math class — those word problems without formulas, just a bunch of facts to solve.

But life is full of stories.  I overcame my disgust, learned how to turn word problems into formulas, and became a math major.  Thus when I wrote about starling flocks last Friday I began to wonder…

How did the starling population increase from 100 birds released in Central Park in 1891 to 200 million (or more) in 2013?

Using information on their breeding habits and survival rate, I did some crude mathematics and came up with an answer.  First, the facts:

  • Starlings north of the 48th parallel produce only one brood per year, the rest produce two.  (To give you an idea of this location, the western U.S.-Canada border is at the 49th parallel.)
  • Female starlings typically lay 5 eggs per nest.
  • 50% – 80% of the eggs survive to the fledgling stage.
  • 20% of the fledglings survive to adulthood.
  • 60% of the adults survive each year.

(Warning!  If math makes your head spin, now’s the time to skip to the end.)

If we started with 100 starlings in Pittsburgh this spring, how many starlings would we have next spring?   To make it simple I made some big assumptions and did a lot of rounding.

  • 100 starlings = 50 nesting pairs
  • 50 pairs * 2 nests per year * 5 eggs per nest = 500 eggs this year
  • 50% to 80% of the eggs will fledge.  I used 65% * 500 eggs = 325 juvenile starlings in August.  I rounded this down to 300.
  • 100 adults + 300 juveniles = 400 starlings in August.   This is why we see so many starlings in the fall — and this doesn’t even include the migrants.
  • 60% of the adults survive to the next spring = 60% * 100 = 60 adults in March
  • 20% of the juvies survive the winter = 20% * 300 = 60 former juveniles in March
  • 60 adults + 60 of last year’s juveniles = 120 starlings in March

If I’m right (but I’m not) our starling population increases 400% in August, then winter trims it to an annual increase of 20% by March.

But 20% is too high.  Sixteen pairs survived from the 100 birds released in Central Park in 1891.  If their increase had been uniform it would resemble compound interest over 120 years (1891 to 2011) of about 14%.

(If you skipped the math, join me here.)

Interestingly, scientists estimated that the starling population boom in the western U.S. in the 1970’s was 16% per year, so I got close.

Fortunately the starling population seems to have stabilized so their annual increase is now — perhaps — zero.

How’s that for a story problem?

 

(photo by Bobby Greene)

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