Yearly Archives: 2010

How do you know it’s a moth?

Chickweed Geometer Moth, Hillman State Park, August 2011 (photo by Dianne Machesney)

24 August 2011:

Most moths are nocturnal but Dianne Machesney found this Chickweed Geometer Moth during the day at Hillman State Park.

How can you tell it’s a moth?

First clue: Is it flying?  Moths fly at night(*), butterflies fly during the day.

Second clue: How does it hold its wings when resting?  Moths open their wings flat (as above) or fold them tightly flat over their backs. Butterflies hold their wings upright, clapped shut above their bodies(**). Click here to see an illustration of these postures.

Third and Best Clue: Look at its antennae.  Moths have fuzzy antennae with many tiny branches.  Butterflies have smooth antennae with little knobs at the end.

Of course there are exceptions.  The Chickweed Geometer moth flies during the day (* erf!).  However, the males have very fuzzy antennae.  You can tell this moth is a boy.

For more information on the differences between moths and butterflies, see a summary at Live Science or this detailed discussion at Wikipedia.

(photo by Dianne Machesney)

(**) p.s. Skippers are butterflies but their resting posture is halfway between that of a typical moth or butterfly.

Thermometer

23 August 2010

The sounds of nature are dominated by different animals as the growing season progresses in western Pennsylvania:

  • March and early April: Frogs
  • April, May, early June: Birds
  • mid-June, July, August: Insects

Crickets start and end the “bug noise” season with a chorus in mid June that continues right up to the first frost.  Until it freezes crickets don’t seem to care what temperature it is.  They just chirp faster in the heat, slower in the cold.

Did you know you can use a cricket’s chirp like an audio thermometer?  Count the number of chirps of a lone cricket for 15 seconds, then add 37.  Ta dah!  That’s the approximate temperature in Fahrenheit.

I’ve found this formula works well on a chilly September evening because the cricket chirps are distinct and slow but it fail my test on hot days.  I always wonder, did I miscount?

Click here to listen to fall field crickets (Gryllus pennsylvanicus) at the Songs of Insects.

 

(drawing of a female common black cricket, Gryllus assimlis, by R.E.Snodgrass of USDA from Wikimedia Commons; click on the image to see the original.)

p.s. The cricket in the illustration is female due to her long central “tail,” the ovipositor.

Bald Blue Jays

Oh my gosh!  What happened to this bird?  Is he ill?

No, he’s molting. 

This week has been notable for the number of bald blue jays hanging out in my neighborhood.   The first one gave me a shock but now there are three and I’m getting used to it.  

Many birds are molting now but most of them lose a few feathers at a time so it’s not noticeable.  The exceptions – usually blue jays and cardinals – really stand out. 

They’re not unique to Pittsburgh.  This bird was photographed by Nancy Castillo who writes The Zen Birdfeeder in Saratoga Springs, NY. 

So why am I seeing three blue jays with bald heads?  At this time of year blue jays hang out in family groups so I might be observing a family with an inherited trait for temporary baldness.

Frankly I can’t wait until they’ve grown their new head feathers.  I’m embarrassed for them but it’s nothing a little time won’t heal.

(photo by Nancy Castillo.  Click on the photo to see her blog about this bird.)

Incoming!!


Watch out below!  This green heron is zooming in for a landing!  

We normally see green herons from above and they look both green and chunky

This bird is likely a juvenile and from “straight on” he doesn’t look like a green heron at all.  Notice his foreshortened beak and big crest, his striped brown neck.  Wow, he’s thin!

For an even more stunning photo of a green heron, click on the photo above to see Steve Gosser’s website.

(photo by Steve Gosser taken at Conneaut, Ohio)

Anatomy: Chin

A bird’s chin is exactly where you’d expect it to be — just under its beak — but of course birds’ chins don’t stick out like ours do.

Shown at right are common redpolls whose feathers give them a black chin (indicated by the blue arrow).  From a distance their black faces and chins make their yellow beaks stand out. 

I wish I could have chosen a Southwestern bird, the black-chinned sparrow, to illustrate this blog but I could not find a photo that I had permission to use.  Instead you’ll have to click here to see how stunning a gray bird with a black chin can be.

(photo by Mark McConaughy taken in January 2008 during a Common Redpoll irruption in western Pennsylvania)

Sad News about “Yellow”

Yesterday the juvenile female peregrine from Pitt nicknamed “Yellow” was found dead at Allegheny Center on the North Side with a broken neck.  She apparently hit a building.

Yellow had a hard, short life.  On June 24 she was rescued from the Webster Hall chimney where she was trapped and dehydrated.  Yellow spent many weeks in rehab and was in good condition when she was released late last month.  Alas, she didn’t make it.  The Fates were against her.

I’m Watching You


Last week’s Pop City slideshow was so nice that I asked the photographer, Brian Cohen, if I could feature another of his peregrine photos this week.  Here’s one from the Gulf Tower Banding in 2009.

After the chicks were returned to the nest that day, both adult peregrines perched on the nestbox roof and looked into the office window that’s normally obscured by blinds. 

Here, Louie gazes intently as the office crowd dissipates.  Brian gazes back and snaps his picture.

“I’m watching you.”

(photo by Brian Cohen)

Summer Beauty: Boneset


Watch for Boneset (Eupatorium perfoliatum) blooming now in western Pennsylvania.

Boneset’s common name comes from the old-time theory that boneset’s joined leaves meant it would heal broken bones.  Its scientific name, perfoliatum, also refers to the joined leaves which are perforated by the plant stem, as shown above.

If you haven’t seen boneset blooming yet, you can find it at Jennings Prairie.

(photo by Chuck Tague)

How do cowbirds know they are cowbirds?


Earlier this month I visited Cape Cod and enjoyed sitting on my sister-in-law’s porch watching the birds go by.  One morning I saw a gang of two dozen birds land in her yard and poke through the grass looking for food.  They were the same size and color as juvenile starlings but they had black feather patches visible among the brown.

What could they be?  With binoculars I was able to identify them as teenaged brown-headed cowbirds, molting into adult plumage.

If you think about how cowbirds grow up, it’s a wonder this gang existed at all.

Cowbird mothers lay their eggs in the nests of smaller birds.  Each cowbird chick is raised, not by its own mother, but by foster parents of another species.  Yet instead of flocking with their foster families these young cowbirds had found each other.

How did they do it?

Juvenile brown-headed cowbirds, even while in the nest, are attracted to the sounds of their own species, especially the chatter call.  As they grow up they pay attention to what they themselves look and sound like.  Occasionally adult cowbirds, possibly their parents, visit near the foster nest and show them cowbird behavioral tips.

When the juvenile cowbirds become independent of their foster parents they use these visual and audio cues to find others of their own kind.

Their first winter is crucial.  Studies have shown that if they’re forced to hang out with another species all winter, they think they’re a member of the other species and are confused for life.

So these teenage cowbird gangs serve a purpose.  Without them, cowbirds wouldn’t know they are cowbirds.

Maybe that would be OK.

(Read Marianne’s comment below to see why.)

 

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

Whose Baby?


Diane Korolog sent me this photograph of a baby bird.  Can you guess what species this is?  Here are some hints:

  • Look at its head shape, beak, nares and eye.
  • How about those claws?  What does this bird do with it’s feet?
  • He is not native to North America and
  • He is a very smart bird.

Bonus points for the exact species!

(photo by Diane Korolog)