Monthly Archives: July 2015

Little Eats Big … Slowly

Insects, Schenley Park
Harvestman with mites on its legs (photo by Kate St. John)
Harvestman with mites on its legs, Schenley Park (photo by Kate St. John)

We’re used to top predators eating small prey but the world is far more complicated than Big Eats Little.  Small things can weaken a predator or bring it down.

Harvestmen (Opiliones), also called daddy long-legs, are omnivorous ‘bugs’ distantly related to spiders.  They are harmless to humans but can be dangerous to small insects.  However they can be weakened by even tinier parasites.

See those two red dots on the harvestman’s legs?  They are parasitic mites sucking the harvestmen’s “blood.”  Bugguide.net identifies them as a species of Leptus (family Erythraeidae) whose larvae parasitize North American harvestmen.

Just two mites are probably not a problem but a large infestation on the body weakens the harvestman.  If seeing bugs-on-bugs doesn’t bother you, click here for an example.

Harvestmen clean their legs by drawing them through their jaws so it’s a wonder the mites remain in place.  Obviously there’s been a long mutual evolution of cleaning and clinging that brought these two species to where they are today.

No matter how small the predator, there’s always something smaller to oppress it.

 

(photo by Kate St. John)

What to Look For in Early July

Phenology
Common Milkweed close-up (photo by Marcy Cunkelman)
Common Milkweed (photo by Marcy Cunkelman)

Throw Back Thursday (TBT):

What can we expect outdoors in early July?  Click here for my prediction, written in 2009:  Milkweed or What to Look for in Early July.

In 2009 I described how to find monarch butterfly eggs on milkweed leaves.  Sadly, monarchs have declined so precipitously in six years that they’re very hard to find today in western Pennsylvania.

 

(close-up of Common Milkweed by Marcy Cunkelman)

Pitt Peregrine Fledgling Update from ARL

Peregrines
2015 Pitt peregrine fledgling checked by vet (photo courtesy ARL Wildlife Center)
2015 Pitt peregrine fledgling checked by vet (photo courtesy ARL Wildlife Center)

Peregrine Update from Animal Rescue League Wildlife Center, 1 July 2015, 11:40am via Facebook … for the bird known as “Silver”:

“Wildlife Center staff took the falcon to be examined by Dr. Robert Wagner yesterday evening. A complete physical examination was conducted. The formerly missing primary feathers are almost completely grown, but our licensed rehabilitators & the veterinarian agree that the bird displays neurological deficits. A blood sample was taken to gain insight on these inconsistencies. A test is also being conducted to rule out lead poisoning. Supportive care will continue as the test results are pending. The falcon will continue to be treated by Wildlife Center staff.”

 

(photo courtesy Animal Rescue League Wildlife Center Facebook page.  Click on the image to visit their Facebook page)

Mr. Mouse Went A-Courting

Mammals
House mouse (photo via Wikimedia Commons)
House mouse (photo from Wikimedia Commons)

1 July 2015

Did you know that male mice sing to attract the ladies?

We can’t hear their songs because they’re way too high for our audio range but each species has its own song and they vary the tunes to fit the social setting.

I learned about this in April’s Audubon news when they highlighted Duke University’s research into mouse songs.  The article included this video of two mouse songs with the audio track digitally lowered so we can hear it.

First a researcher places fresh female urine in the male’s enclosure. Mr. Mouse can smell her but can’t see her so he sings a loud and complex song.  Next they put a female in the male’s enclosure.  When he finds her (why does it take so long?) he snuggles up and sings a softer, simpler song.

Male Mouse Singing To Woo Mate from Audubon.org on Vimeo.

Male Mouse Singing To Woo Mate from Audubon.org on Vimeo.

What do the lady mice think?  When placed alone in an enclosure with a speaker playing male songs, most females stay close to the speaker when the complex songs play.  Perhaps those songs say “Come hither!”

Click here to read more in Audubon Magazine.

p.s. At 50kHz we humans can’t hear mice sing … but cats can!

(video from audubon.org’s Vimeo site. photo of a house mouse from Wikimedia Commons; click on the image to see the original.)

The title is a reference to “Frog Went A-Courting” in which Frog sings to woo Miss Mouse.