Jan 10 2017

How Museums Saved The Peregrine Falcon

Two specimens, Peregrine Falcon egg clutches, anatum subspecies, Carnegie Museum (photo by Steve Rogers)

Two specimens of peregrine falcon egg clutches at Carnegie Museum, collected at Baja California in 1921 (photo by Steve Rogers)

What good is a museum collection of bird eggs?  In the case of peregrine falcons, egg collections helped save the species.

After World War II new organochlorine insecticides were introduced on the open market and widely used in agriculture. Some of them, such as seed dressings of dieldrin, aldrin and heptachlor, instantly killed birds as they fed in the fields.  DDT was more insidious.

By the mid 1960s, seed dressings were already banned in Britain but the peregrine population was still crashing and Derek Ratcliffe wondered if something else was going on.  Since 1951 he and other peregrine monitors had seen many broken eggs in eyries and frequent nest failure.  Ratcliffe wondered if peregrine eggs were collapsing because the eggshells were thin.  He decided to find out.

Egg collections are empty shells (notice the tiny drill hole in each specimen above).  You must not break them to measure the shell’s thickness.  However the weight of the shell correlates to thickness if you account for the size of the egg.  Ratcliffe weighed each egg and measured its length and width.  Then he used this formula to determine its thickness index.

Shell thickness index = Weight of eggshell (mg) / [Length (mm) * Breadth (mm)]

For his preliminary study, Ratcliffe measured egg specimens in the British Museum of Natural History and 30 eggs collected in more recent peregrine surveys.  Indeed the shells had thinned since World War II, prompting further research.

Ratcliffe’s final study, published in 1967, showed that the turning point in Britain was in 1947.  Prior to that shell thickness averaged a steady 1.82 for over 125 years.  After 1947 the thickness dropped to 1.53, an average loss of 16%.  (Later studies showed trace amounts of DDE in the shells.)

Meanwhile, Hickey and Anderson at the University of Wisconsin wondered if eggshells were thinning in North America, too.  Their 1968 study measured eggshells of 13 raptors and 9 fish-eating birds and found that, yes, peregrine falcons were affected by DDT in the U.S.

Peregrine populations were crashing on two continents because of overwhelming nest failure in the face of DDT.  Political and legislative wheels turned slowly.  DDT was banned in the U.S. in 1972. Then the peregrine falcon recovery began.  By 1999 peregrines were doing so well in the western U.S. that they were taken off the U.S. Endangered Species List.

Museum egg collections played a key role in this happy result.  It’s not a stretch to say that museums helped save the peregrine falcon.


(photo by Steve Rogers from the Section of Birds at Carnegie Museum of Natural History)

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Jan 09 2017

Let’s Go To The Aviary, January 22!

Published by under Books & Events

Hyacinth macaw at the National Aviary in Pittsburgh (photo by Christopher Westfield via Wikimedia Commons)
UPDATE, JAN 17: No More Reservations accepted. The tour is full.

Let’s go birding indoors!

Join me for a guided tour of the National Aviary with Aviary docent (and Falconuts founder) John English.

When:  Sunday January 22, 10:00am to noon. Stay longer if you wish and browse on your own.

Where: The National Aviary
700 Arch Street, Pittsburgh, PA 15212
**  Meet at the Concierge Desk inside the East Entrance on Arch Street.  **

Who:  This outing is limited to 25 people, first come first served.  You must register by leaving a comment on this blog post by Jan 16 5pm. Include your name + email address and the names of everyone coming with you. (Note: Your information will not appear on the website. The comment will come to me alone.)

Cost: $10.00, cash or check only. (Check made out to the National Aviary.)
* For this special event, admission is free to all who’ve pre-registered.
* Add-ons: Bird shows and feedings will cost the normal rate.

Hope you can make it!  I’m looking forward to seeing you.

For directions and information about the National Aviary, see their website at www.aviary.org

Remember, reservations are required so post a comment to reserve your space today!

UPDATE, JAN 17: The tour is full!

(photo of Hyacinth Macaw at the National Aviary by Christopher Rice at Wikimedia Commons. Click on the image to see the original)



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Jan 09 2017

More To A Giraffe Than Meets The Eye

Published by under Mammals

Giraffe in Namibia (photo from Wikimedia Commons)

Giraffe in Namibia (photo from Wikimedia Commons)

Any way you look at it, giraffes are amazing animals. At 15 to 20 feet high they’re the tallest mammals on earth … and that’s not all:

  • Just like us giraffes have only seven bones in their necks but the bones are so big that males have necks six feet long (1.8m). Females are a bit shorter.
  • Giraffes get by on very little sleep. They need only 10 to 120 minutes per day.
  • Like zebras’ stripes, tundra swan beaks, and human fingerprints, the spots on giraffes are unique to the individual.
  • Giraffes can go without water longer than camels.
  • Female giraffes give birth standing up.  Their babies fall five feet to the ground yet within an hour can stand and run.
  • The giraffe’s height lets him eat leaves on tall trees …
Giraffes eating among the leaves (photo from Wikimedia Commons)

Giraffes eating among the leaves (photo from Wikimedia Commons)

  • … but makes it awkward to reach the ground. Here’s what giraffes have to do to drink!
Giraffes drinking, Namibia, Etosha (photo by GIRAUD Patrick via Wikimedia Commons)

Giraffes drinking, Namibia, Etosha (photo by Giraud Patrick via Wikimedia Commons)

  • Female giraffes prefer to mate with the tallest males.
  • Male giraffes fight for access to the females by swinging their necks and whacking each other with their heads and horns.  Long necks are an advantage.   Watch a fight below.

  • And finally, giraffes have big hearts. Literally. Their hearts are two feet long and weight 25 pounds.


p.s. Oh no!  On December 9, 2016, the giraffe was placed on the Endangered Species List by the International Union for the Conservation of Nature, the group that administers the list. Giraffes are now in the Vulnerable category. Read more in Smithsonian magazine.

(photos from Wikimedia Commons. click on the images to see the originals. video from shashaenright on YouTube)

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Jan 08 2017

Frost Flowers

Published by under Plants

Frost flower in Sheperherdsville, Kentucky (photo from Wikimedia Commons)

Frost flower in Sheperherdsville, Kentucky (photo from Wikimedia Commons)

Here’s something I’ve never seen before because I live too far north.

Frostweed (Verbesina virginica) is a plant in the Aster family native to the southeastern U.S., the lower Mississippi valley, and Texas.  It’s closely related to our familiar wingstem (Verbesina alternifolia) but it doesn’t grow here.  Alas.

Biota of North America Program (BONAP) map of Verbesina virginica, 2014 (linked from bonap.net)

I say “Alas” because, when conditions are right, its stems exude water and create stunning frost flowers when the temperature drops below freezing.

Meredith O’Reilly of Austin, Texas displays photos of these beautiful ice sculptures, here at her Great Stems blog.  And see more of them here at The Frost Below.


Thank you to Allen Janis for alerting me to these delicate winter structures.

(photo for frost flower from Wikimedia Commons; click on the image to see the original. Range map of frostweed liked from Biota of North America Program ( BONAP) map of Verbesina virginica)

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Jan 07 2017

7 Peregrines, 7 Merlins

Peregrine on porch railing at Lawrence Hall, 30 Sep 2016 (photo by Lori Maggio)

Peregrine on porch railing at Lawrence Hall, 30 Sep 2016 (photo by Lori Maggio)

Seven was the magic number for two iconic falcons during Pittsburgh’s Christmas Bird Count last weekend.

During Count Week, which includes the three days before and after Count Day (31 Dec 2016), observers saw seven peregrine falcons and seven merlins within the circle.

Two of the seven peregrines were elusive on Count Day but visible during Count Week.

  • 2 at the Cathedral of Learning on 30 December, (We saw one on Count Day.)
  • 1 Downtown at Lawrence Hall on 2 January 2017, perched as shown in Lori Maggio’s photo above,
  • 1 in Kilbuck Township on Count Day December 31,
  • 1 in Oakmont area on Count Day,
  • 2 in Shaler Township on Count Day.
Merlin (photo by Chuck Tague)

Merlin (photo by Chuck Tague)

All seven merlins were seen on Count Day, December 31:

  • 1 in the Oakmont area
  • 3 in Penn Hills
  • 3 in the City of Pittsburgh: 2 at Schenley Park and 1 along the Ohio River within the city limits.

So if you’re looking for falcons this winter, visit Pittsburgh’s 7-mile-radius count circle shown below.

Map of Pittsburgh's Christmas Bird Count circle, PAPI (screenshot from Audubon Society Christmas Count map)

Map of Pittsburgh’s Christmas Bird Count circle, PAPI (screenshot from Audubon Society Christmas Count map)

Seven is the magic number.


(photo of Downtown peregrine by Lori Maggio, photo of merlin by Chuck Tague. Screenshot of Pittsburgh Count Circle map from Audubon CBC website; click on the image to see the original)

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Jan 06 2017

I’m Not A Sea Gull

Published by under Water and Shore

Ring-billed gull in non-breeding plumage, Lake Erie, Ohio (photo from Wikimedia Commons)

Ring-billed gull in non-breeding plumage, Lake Erie, Ohio (photo from Wikimedia Commons)

Some people call them “seagulls” but this species doesn’t care about the sea.

Ring-billed gulls (Larus delawarensis) are surprisingly continental birds. Most breed in interior North America, migrate near fresh water, and spend the winter on the coast or at inland lakes and rivers, landfills and shopping malls.

They like to live near water because it’s safer to sleep on water than on land, but they don’t need the ocean at all. A lake or river will do.  And parking lots are marvelous for daytime loafing.

The ring-billed gull’s range map, linked here from All About Birds, shows their inland preference.  It’s the reason why they’re so plentiful in Pittsburgh in the winter.

Range map of ring-billed gull (Larus delawarensis), linked from All About Birds website


To prove their land-loving ways, here are three ring-billed gulls courting and arguing far away from the ocean. The parking lot is in Crystal Beach, Ontario across the water from their large nesting colony in Lackawanna, New York.


Ring-billed gulls will tell you, “I’m not a sea gull. I’m just a gull.”


p.s. That’s why birders call this group of birds “gulls” not “seagulls.”

(photo from Wikimedia Commons, range map linked from AllAboutBirds.org. Click on the images to see the originals in context.  Gull video by Jay Burney on YouTube)

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Jan 05 2017

Owls Come A’Courting

Great-horned owl, hooting (photo by Chuck Tague)

Great-horned owl, hooting (photo by Chuck Tague)

On Throw Back Thursday:

January’s the month when great horned owls court and nest in southwestern Pennsylvania.  If you hear them hooting, they’re planning to nest in your neighborhood.

Read more about their courtship and hear them hooting in this vintage article from 2010:

Whoooo Said That?


p.s. Listen in South Oakland near the Anderson Bridge. The pair in Schenley Park will let you know they’re there.  🙂

(photo by Chuck Tague.  The owl’s white throat feathers are showing because he’s hooting.)

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Jan 04 2017

Bald Eagle Hatchling in Florida

Published by under Birds of Prey

Screenshot from Southwest Florida eaglecam

Screenshot from Southwest Florida Live Eaglecam

Are you anxious for bald eagle season to get underway in Pittsburgh?   Can’t wait to watch baby eagles on camera?  Get a jump on the season at the Southwest Florida Eaglecam.

Bald eagles M15 and Harriet are nesting in Fort Myers, Florida in view of three eaglecams.  This year Harriet laid two eggs and one hatched on December 31.  Their eaglet is already growing.

Click here or on the image above to watch M15, Harriet and eaglet E9.  Will Harriet’s second egg hatch?  We’ll have to wait and see.


p.s. Thanks to Tom Balistreri (@tombalist) for alerting me to this happy event.

(screenshot from Southwest Florida Live Eagle Cam sponsored by Dick Pritchett Real Estate.  Click on the screenshot to watch the eaglecam.)

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Jan 03 2017

Pennsylvania’s Native Parrot

Carolina parakeet specimen tag #2513, Carnegie Museum (photo by Kate St. John)

Carolina parakeet specimen tag #2513, Carnegie Museum (photo by Kate St. John)

Two hundred years ago wild parrots lived in Pennsylvania.  Now you find them only in museums.  This one is at the Carnegie.

Carolina parakeets (Conuropsis carolinensis) were gregarious birds who lived in heavily forested areas along rivers and swamps from New York to Florida and west to the Mississippi.  In flocks of 100 to 1,000 birds they nested in hollow trees and ate fruit and seeds, especially the seeds of cockleburs (Xanthium sp.).

As European settlers fanned out across North America we cut down the trees and planted orchards.  Habitat loss and hunting as orchard “pests” put pressure on Carolina parakeets.  John James Audubon noticed the bird’s decline as early as 1832.

By 1878 Carolina parakeets lived only in central Florida but they seemed to be doing well there.  This specimen from Carnegie Museum was collected in 1896 in Osceola County, south of Orlando, Florida.

Carolina parakeet specimen #2513, Carnegie Museum (photo by Kate St. John)

Carolina parakeet specimen #2513, Carnegie Museum (photo by Kate St. John)

Unfortunately, wild Carolina parakeets disappeared suddenly in the early 1900s.  The last captive bird died in the Cincinnati Zoo in 1918.  Conuropsis carolinensis was declared extinct in 1939.


What was it like to live near wild parrots?  Museums mounts give us a hint at their beauty …

Carolina parakeet mounted specimen, Museum Wiesbaden, Germany (photo from Wikimedia Commons)

Carolina parakeet mounted specimens, Museum Wiesbaden, Germany (photo from Wikimedia Commons)

… but for a real taste of the wild flocks go see their nearest relatives, black-hooded parakeets (Aratinga nenday), in Florida and California.  I’ve seen them at Boynton Beach, Florida as described in this vintage article:

A Taste of What We Never Knew


(specimen photos by Kate St. John. photo of taxidermy mount at Museum Wiesbaden, Germany from Wikimedia Commons; click on the image to see the original)

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Jan 02 2017

Reminder: Scavenger Hunt on Jan 8

Barn owl taxidermy mount in case, Carnegie Museum (photo by Kate St.John) Just a reminder that I’m holding an Scavenger Hunt outing at Carnegie Museum of Natural History on Sunday, 8 January 2017, 1:00pm to 3:00pm.

Meet me in the big hallway on the first floor between the Art and Natural History Museums at 1:00pm.  It’s the “Museum of Art Lobby” on this map.

After a brief introduction we’ll go up-and-down to the back of the 2nd floor where we’ll hunt for birds in the dioramas.

Hope to see you there.


Note:  If you’re not a museum member there’s a fee to get in:
Adults $19.95
Seniors (65+) $14.95
Students with ID and children 3-18 $11.95


Click here for admission information and here for directions.

(photo by Kate St. John)

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