Yearly Archives: 2010

Anatomy: Preen Gland

Bird Anatomy

If you watch birds preening you’ll often see them twist their necks over their backs, touch the tops of their tails with their bills, and groom their feathers.

The spot they’re touching is the uropygial or preen gland.  It has nipple-like pores that secrete preen oil to keep their feathers supple and suppress parasites.

Preen oil also provides some waterproofing.  Perhaps that’s why this gland is best developed in petrels, pelicans and ospreys.

Preening is vital for birds’ survival.  Besides removing feather and skin parasites and spreading preen oil, birds do it to peel the scales off pin feathers and comb the feather barbules back into place.  Feathers must be in their original shape with all the barbules interlocking in order to fly well and stay waterproof.  Preen oil probably holds the feathers in their combed position just as our oily hair products keep our hair in place.

Not all birds have preen glands — ostriches and emus don’t — but waterfowl do.  In this photo a female common eider is pointing her long white bill directly at her preen gland.  You’ll see this often if you watch ducks.

You’ll also see it if you watch peregrines because they must keep their feathers in tip top shape for precision flight.

Does preening waterproof them?  When my friend Karen sees the Pitt peregrines touch their preen glands she says, “It’s going to rain.”

(photo by Chuck Tague)

Gorgeous

Peregrines

Portrait of a young peregrine, by Brian Herman.

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And, unrelated to this photo, news of the Westinghouse Bridge peregrines:
Beth Fife and Doug Dunkerley banded three male chicks at the Westinghouse Bridge yesterday. The bridge is very high and it was very windy. As Beth wrote, she and Doug “Held on with our lives!!!!!!!! ”

The mother peregrine, “Val” (“Storm” from Canton, Ohio, 2005), was present.  The father peregrine stayed away.  Neither bird was a problem compared to the scary winds on such a high structure.

(photo by Brian Herman)

Becoming Silent

Bird Behavior, Schenley Park, Songbirds


Remember when the robins woke you up before dawn?  When they sang all night?  It was only last month.

Now that it’s mid-June there’s a lot less birdsong in the morning.  They still sing but they lack the frantic edge they had in May.

Their reason for singing is quickly disappearing.  They’ve established territory and found a mate.  They have eggs in the nest or babies to feed.  Some sing less when they have nestlings, perhaps to avoid attracting attention to their vulnerable family.

And if they haven’t nested yet, they’ve given up.

I noticed a gap last week in yellow warbler song when I suddenly heard them again in Schenley Park after a three week hiatus.  Why did they stop singing?  I don’t know, but their songs are half-hearted now.

The robins are half-hearted too.

By the middle of July the serenade will be over.

Alas.  Just as I got my ears in tune to identify birdsong there will be nothing to practice with.

(photo of a yellow warbler by Chuck Tague)

One, Two, Three, Go!

Peregrines


After spending a week at St. Paul’s Cathedral, Pitt’s young peregrines returned to campus yesterday.  I found three of them perched on Heinz Chapel steeple while their parents claimed the heights of the Cathedral of Learning. 

It was a role reversal, but one I could understand.  The “kids” have been on the wing for two weeks and they fly so well now that they can chase their parents everywhere.  In fact, they do.  Dorothy and E2 made it clear yesterday that for the moment they wanted to be left alone.  To emphasize her point Dorothy was roosting.

I’m amazed at how quickly young peregrines learn.  Only eleven days ago they were clambering on the 25th floor roof when Kim Thomas captured this photo of Green Boy with open wings and cocked tail.  He was ready to glide from his little hill of roof tiles and seems to be telling himself,  “One, two three, go!”

Now the Pitt youngsters are beyond this “toddler” stage and the Gulf Tower chicks are about to enter it.  Soon the Gulf chicks will be practicing on a roof Downtown.

One… two… three… Go!

(photo by Kimberly Thomas)

Like Butterflies

Bird Behavior, Nesting & Courtship


When does a bird look like a butterfly?  When it appears to be nectaring in mud.

Over the weekend I stopped at the Rt.528 bridge at Moraine State Park to see a colony of unusual birds who nest underneath it.  Cliff swallows hang their jug-shaped nests from the bridge structure so I go there to watch them pop in and out of the nests and wheel over the parking lot.

On Saturday they were busy building, carefully gluing mud daubs to the cement, then flying away for more.  Where did they get the mud?

I found half the flock in a mud puddle, packed closely together, tiptoeing through the muck and holding their wings and tails erect to keep them clean.  All their wings were quivering, just like butterflies.  Are these “swallowtails?”

Chuck Tague saw them too and photographed their mudfest.  In the process he documented a new behavior among cliff swallows — they mix plants in the mud — and wrote a blog about it.  His descriptions are better than mine.  See his blog here.

(photo by Chuck Tague)

Gulf Tower Antics

Peregrines


Traci Darin sent me this snapshot from the Gulf Tower webcam yesterday — all five nestlings in one shot.

The young peregrines at the Gulf Tower in Pittsburgh are at the ledge-walking stage and are hamming it up on camera.  Where one goes the others follow, if only to look in wonder.

Sometimes they walk or jump off camera.  Where do they go? 

If they disappear at the lower edge of the photo, they’re in the gully below the nest.  Here, two of them are on the ramp that goes there.

When they disappear to the right they’re on the windowsill.  If they go to the left they’re on top of the pillar (like their mother in this photo) or exercising their wings at the launch point.

In about ten days they’ll be gone from the nest.  For now, you can see them here.

I’m sure their parents won’t have Empty Nest Syndrome, but we will.

(photo from the Gulf Tower webcam, captured by Traci Darin)

Heal-all

Plants & Fungi


Heal-all (Prunella Vulgaris) may be a weed but it’s good for us.  Also known as Self-heal, it’s a medicinal plant with antibacterial qualities that treats a wide variety of illnesses.

Newcomb’s Wildlfower Guide doesn’t call it “non-native” because its presence in North America pre-dates known travel records.  Did it come here on its own or did people bring it?

Native Americans use heal-all as medicine so perhaps the first Americans brought it across the land bridge from Asia.  And now it’s here to stay.

Watch for Heal-all blooming throughout the summer.

(photo by Dianne Machesney)

Anatomy: Feet

Bird Anatomy, Musings & News
Diagram of bird toe arrangements (image from Wikimedia Commons)

Bird species have different feet to match their lifestyles. Most have four toes but some have as few as two. Toe position varies, too.

The diagram above shows four of the six variations and assigns a number to each toe. The number is echoed in the drawing by number of segments. For instance, toe #1 has 1 segment, toe #3 has 3 segments.  That’s why the feet look falsely lopsided.

Here’s what the four words mean.

The suffix dactylie is Greek for “fingers.”

Aniso = unequal. Three toes forward + one back is unequal = Anisodactylie.

Zygo = yoke = “arranged symmetrically in pairs.”  Toes 2 and 3 point forward, 1 and 4 point back. Woodpeckers and parrots have zygodactyl feet.

Tridactyl: tri = 3 toes. Emus!

Didactyl: di = 2 toes. Ostriches!

Two arrangements are not shown: 

  • Heterodactyl is like Zygodactyl except that toes 3 and 4 are forward and 1 and 2 are back.  Trogons are heterodactyl.
  • Pamprodactyl has all four toes pointing forward.  Swifts are pamprodactyl with feet like garden claws.

Click here to read more about birds’ feet.

p.s. Did you know that osprey can change the arrangement of their toes? Osprey rotate their outer toes (toe #4) from anisodactyl (for perching) to zygodactyl to make it easier to carry fish.

(diagram from Wikipedia, Creative Commons license. Click on the image to see the original.)

Want to do a Fledge Watch at the Gulf Tower?

Peregrines

The Gulf Tower peregrine nestlings are growing fast and will fly for the first time next week — as early as June 15 but more likely starting Friday June 18. 

Many of you watching the webcam have asked if there will be a Fledge Watch at the Gulf Tower. 

There will be … if you make it happen. 

Due to constraints on my time and location, I can’t organize a Watch at the Gulf Tower but if you visit the area near this building, you’re a candidate for Fledge Watch.

Here’s what to do:

  • Use this blog as your contact point.  Post a comment that you’re interested in Fledge Watch and I’ll put you in touch with each other. 
  • If you want to coordinate the Watch, please say so!  The Watch will go best if someone is locally in charge. 
  • Pick a place to locate the Watch.  The best side to watch from is here.  Where will you meet?  Agree on a location and I’ll post it on the blog.
  • Show up whenever you can during daylight.  The chicks prefer to fledge when there’s low humidity and a good wind but they will fly at any time bceause they become very restless at the fledging stage.
  • The first-flight period will last five to seven days from first bird to last — probably June 17-24.
  • Bring binoculars and possibly something to sit on.
  • Chances are you won’t need this information but I’m including it for completeness:  If a fledgling lands on the ground he will have to be rescued because he can’t lift off the ground in the first day of flight.  Call the Game Commission’s Dispatch Office at 724-238-9523 and they will send someone as soon as possible.  In the meantime watch the fledgling to guard against further accidents.  Do not chase it!  Do not scare it into the street!  Calmly watch it until help arrives.  (It’s easy.  Here’s my favorite picture of guarding a fledgling.  I saved this photo from a fledge watch in Canada in the 1990s.  I haven’t been able to re-find the source.)
  • Have fun!  Fledge Watch is an opportunity to see peregrines and meet others who love these birds too.

Check the comments on this blog for more information. 

(photo of the Gulf Tower in winter by Derek Jensen, released to the public domain on Wikipedia.  Click on the photo to see the original.)

What Can We Do?

Musings & News


When I first heard about BP’s Gulf oil leak, I knew it was bad for birds.

Though initially far offshore, the oil immediately affected diving birds: gannets, terns and pelicans.

The first dead gannet broke my heart.  It could only get worse — and it has.

When the oil reached the marshes it hurt herons, egrets and shorebirds who died unreported because the marshes are inaccessible to cameras.  Even birds that were rescued, cleaned and released flew home to get oiled again because the leak keeps flowing.

Recently oil and death moved into camera range and now the public knows.  The spill is very, very bad.  Even if the leak stopped today the oil will linger for months to come.

What can we do?

As individuals we can’t stop this leak but we can help with the cleanup and support those who are helping birds.  There are many ways:

Want to volunteer in the Gulf?  Check the websites above or click here to sign up at “deepwaterhorizonresponse.com” or here for the International Bird Rescue Research Center.

And finally, you can work to keep this from happening again by telling those in power, especially your Congressman and Senator who made the laws that allowed this to happen, that you’ve had enough.

We don’t have to live like this.

(Coast Guard photo by Petty Officer 2nd Class John Miller, released under the Creative Commons license with some rights reserved.  Click on the photo to see the original and a complete description.)