Archive for the 'Mammals' Category

May 31 2017

An Uneasy Truce

Published by under Bird Behavior,Mammals

Curve-billed thrashers and round-tailed ground squirrel eating mealworms, Tucson, Arizona (photo by Donna Memon)

Curve-billed thrashers and ground squirrel near Tucson, Arizona (photo by Donna Memon)

In Arizona:

These species tolerate each other at the feeder but their relationship is rocky elsewhere.

In Donna Memon’s backyard two curve-billed thrashers wanted this round-tailed ground squirrel to step away from the mealworms.  Though they poked her she wouldn’t leave. This squirrel is so feisty that she chased a roadrunner!

Away from the feeders it’s all out war. Ground squirrels raid bird nests to eat eggs and nestlings.

Curve-billed thrashers try to avoid predation by nesting in cholla cactus.

Cholla cactus with bird nest (photo from Wikimedia Commons)

Cholla cactus with bird nest (photo from Wikimedia Commons)

 

Steve Valasek found an occupied nest at Hassayampa River Preserve northwest of Phoenix.

Curve-billed thrasher nest in cholla cactus (photo by Steve Valasek)

Curve-billed thrasher nest in cholla cactus (photo by Steve Valasek)

Safe from ground squirrels, heat is the big problem at the cactus nest sites.

Curve-billed thrasher and chick pant in the hot nest (photo by Steve Valasek)

Curve-billed thrasher and chick panting in hot nest (photo by Steve Valasek)

 

How do the chicks fledge?  Very carefully!

 

(photo credits:
curve-billed thrashers with ground squirrel by Donna Memon
cholla cactus photo from Wikimedia Commons; click on the image to see the original.
curve-billed thrashers’ nest by Steve Valasek
)

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Mar 13 2017

Of Llamas and Possums

Published by under Mammals,Migration

Llama on Machu Picchu, Opossum in western Canada (photos from Wikimedia Commons)

Llama on Machu Picchu, Virginia opossum in western Canada (photos from Wikimedia Commons)

What do llamas and opossums have in common?

Their ancestors swapped continents during the Great American Interchange.  They now live a world away from their country of origin.

The “Great American Interchange” sounds like a flea market or a swap meet but it’s actually the movement of species between North and South America when the two continents joined at Panama three million years ago.

Before the interchange our continent had members of the camel family; South America did not.  The camelids walked south and thrived on their new continent in the wild as guanacos and vicuñas and domesticated as llamas and alpacas.  In the meantime camels went extinct here in North America.  So there are wild camels in Peru but we have none.

Other animals made the journey, too. Here are just a few of the northern species that became successful in South America: camelids, squirrels, cottontail rabbits, deer, wild horses, peccaries, otters, raccoons, wolves, cougars, American sparrows (Emberizidae), trogons and condors.  Click here for the complete list.

Initially the interchange was symmetrical with the same number of species going north and south but the result was lopsided.  More northern species survived their move to South America than did southern species transplanted to the north.  This was due in part to the difficult trek northward (deserts en route), our less hospitable climate (winter!) and the long isolation of South American fauna.

Opossums were one of the few success stories.  We had no marsupials in North America until the Virginia opossum’s ancestors made the journey and thrived on our continent.  Many of their relatives still live in South America.

So what did we get when South American animals walked north?  Not as much as you’d think: opossums, armadillos, porcupines, cougars, parrots, hummingbirds, tanagers, and tyrant flycatchers.  Click here for the complete northbound list.

Cougars (Puma concolor) are on both lists because they were originally from North America and walked into South America. After they went extinct in North America the southern ones walked north to repopulate our continent.

We humans were part of the Great American Interchange, too.  Our species’ movement around the globe was made possible by continental land bridges.

 

(photos from Wikimedia Commons: llama at Machu Picchu, Virginia opossum in western Canada. Click on each link to see the original.)

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Mar 07 2017

Not A Squirrel

Published by under Mammals,Travel

Central American agouti, in Panama (photo from Wikimedia Commons)

Central American agouti, in Panama (photo from Wikimedia Commons)

What rodent is as big as a groundhog, looks like a squirrel, and has long legs like a small dog?

The agouti (pronounced “a GOO tee”) lives in forests, nests in burrows, and eats fallen fruit and nuts.  Eleven species in the genus Dasyprocta range from Mexico to South America and in the Caribbean.  Four are endangered because of habitat loss and over hunting but the Central American agouti (Dasyprocta punctata), the species I saw in Costa Rica, seems to be doing fine.

Agoutis look like very large squirrels but their bony legs and extremely short hairless tails set them apart.

Central American agouti, walking in Gamboa, Panama (photo from Wikimedia Commons)

Central American agouti in Gamboa, Panama (photo from Wikimedia Commons)

Like squirrels, they are diurnal but avoid humans because we hunt them.  Where they feel safe, though, they’re almost tame. At Las Cruces Biological Station they’re protected so they stroll around the Wilson Botanical Garden and stop by the bird feeders every morning to glean the fruit knocked off the feeders.

This agouti was wary when I followed him at the garden to take his picture.  I was amazed when he raised the greenish fur on his rump when I got too close. He lowered it when I stopped following him.

Agouti at Las Cruces Biological Station, February 2017 (photo by Kate St. John)

Agouti at Las Cruces Biological Station, February 2017 (photo by Kate St. John)

Despite their physical resemblance, agoutis aren’t even related to squirrels.  Their nearest relatives are guinea pigs.

 

(top two photos from Wikimedia Commons; click on the images to see the originals. Last photo by Kate St. John)

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Feb 22 2017

Nothing Like It On Earth

Published by under Mammals

An okapi (photo from Wikimedia Commons)

Okapi at Disney Animal Kingdom, Florida (photo from Wikimedia Commons)

What animal has a body like a mule, stripes like a zebra, and a face like a giraffe?  This one:  the okapi (Okapia johnstoni).

I’d never heard of an okapi (pronounced “o KAH pee”) until I learned that Penn State scientists are leading the effort to sequence the giraffe’s genome.  The project is looking at the okapi’s genes because it’s the giraffe’s only living relative.  Who knew!

Okapis are forest dwelling mammals who eat plants and spend most of the time alone except when breeding. They reproduce slowly as the female is pregnant more than a year (440-450 days) before giving birth to a single foal.  Unlike giraffes, only male okapi’s have horns.

Male okapi showing off its stripes and horns (photo from Wikimedia Commons)

Male okapi showing off its stripes and horns (photo from Wikimedia Commons)

There are okapis in zoos around the world but in the wild they live in only one place, the Democratic Republic of the Congo in the center of Africa, where they are protected by law but still threatened by deforestation, human encroachment, and poaching.  Lawlessness is a threat to okapi survival.  They are listed as Endangered by the IUCN.

To save the okapi, John Lukas founded the Okapi Conservation Project in 1987 to buy land, set up conservation zones and work with local people to protect the okapi and improve the lives of those who live near it.

The project not only reduces human pressure on okapi habitat but relationships within the community save lives.  In the blog post below John Lukas described how poachers with AK47s planned to kill a delegation of okapi conservationists last July.  Locals passed through the ambush zone unharmed but knew their friends were in danger so they notified their chief who warned the delegation.  Read how the ambush was foiled at the link below.

Relationships Built through Community Conservation Foils Ambush by Poachers

 

I hope that okapi conservation is successful.

There is nothing like an okapi on earth.

 

(photos from Wikimedia Commons. Click on the images to see the originals)

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Jan 29 2017

Monkeys And Macaws

White-headed capuchin monkey, Costa Rica (photo from Wikimedia Commons)

White-headed capuchin monkey, Costa Rica (photo from Wikimedia Commons)

On a birding trip in Costa Rica:

Today we’ll be birding at Carara National Park on the Pacific Coast where I expect to see monkeys and the park’s most famous bird, the scarlet macaw.

Encountering monkeys in the wild is a new experience for me.  Because we humans are the only primates who live outside subtropical zones most of us only see primates in captivity.

At Carara we’re likely to see white-headed capuchins (Cebus capucinus), shown above. These diurnal monkeys are highly intelligent and very social, living in troops of about 16 individuals that are mostly female kin because the males move around.  White-headed capuchins love to use tools and are so smart that they can be trained in captivity to assist paraplegics.

If we hear an otherworldly roar like a dinosaur, it’ll be a mantled howler monkey (Alouatta palliata).  The howlers roar both day and night but can be hard to find.

Mantled howler monkey, howling in Costa Rica (photo from Wikimedia Commons)

Mantled howler monkey, howling in Costa Rica (photo from Wikimedia Commons)

Click here to hear the howl while a woman searches for the source. Perhaps they “sound like dinosaurs” because the foley editors used howler voices in Jurassic Park.

 

Today’s highlight, though, will be the beautiful wild scarlet macaws (Ara macao).

Scarlet macaw in Puntarenas Province, Costa Rica (photo from Wikimedia Commons)

Scarlet macaw in Puntarenas Province, Costa Rica (photo from Wikimedia Commons)

These huge members of the parrot family have a wide range — from Central to South America — but they need a lot of territory that’s remote from humans in order to survive.  Carara provides that space.

I hope to see scarlet macaws flying, as in the photo below.  I’ve seen green-winged macaws (Ara chloropterus) in free flight at the National Aviary but seeing scarlets — and in the wild — will be a real treat.

Scarlet macaws in flight, Costa Rica (photo from Wikimedia Commons)

Scarlet macaws in flight, Costa Rica (photo from Wikimedia Commons)

 

And for those of you who love reptiles, there’s a bonus.  Carara National Park has American crocodiles (Crocodylus acutus).  No, they are not alligators. Click here to see.

 

(photos from Wikimedia Commons. Click on the images to see the originals)

Day 3: Carara National Park

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Jan 23 2017

Converged With The Anteater

Published by under Mammals,Musings & News

Indian pangolin, manis crassicaudata (photo from Wikimedia Commons)

Indian pangolin, Manis crassicaudata (photo from Wikimedia Commons)

Last month I randomly opened an encyclopedia for the letter P and found an animal I’d never seen before.  Though he looks like an anteater he’s not related to them.

Pangolins are mammals with long thin snouts and long tails that eat ants and termites.  Instead of having fur they’re the only mammal on earth with scales.  The scales, made of keratin like our fingernails, provide protection.  When a pangolin is attacked it rolls into a ball in the same defensive posture as a porcupine.

Pangolin in defensive posture, Manis temminckii in South Africa (photo from Wikimedia Commons)

Pangolin in defensive posture, Manis temminckii in South Africa (photo from Wikimedia Commons)

Eight pangolin species range from Africa to Asia and Indonesia.  All are in severe decline, listed as vulnerable to critically endangered, because their meat is a Chinese delicacy and folk medicine. Even African pangolins are poached for this illegal trade.

Range map of pangolin species (image from Wikimedia Commons)

Range map of pangolin species (image from Wikimedia Commons)

Anteaters can’t help them. They’re not related.

 

Anteaters are furry mammals with long thin snouts and long tails, native to Central and South America.

Giant anteater at the Pantanel, Brazil (photo from Wikimedia Commons)

Giant anteater at the Pantanel, Brazil (photo from Wikimedia Commons)

They, too, eat ants and termites.

Giant anteater with his snout in an ant hole (photo from Wikimedia Commons)

Giant anteater eating insects (photo from Wikimedia Commons)

 

Anteaters and pangolins resemble each other because they need the same tools to gather food. Similar appearance in unrelated species, called convergent evolution, is true of my favorite bird, too.

Peregrine falcons resemble hawks because they both hunt for meat, but peregrines are more closely related to parrots than to hawks and eagles.  They converged in appearance to get the job done.

 

(photos and maps from Wikimedia Commons; click on the images to see the originals)

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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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Dec 12 2016

Fewer Deer, Less Garlic Mustard

Published by under Mammals,Plants

Deer and garlic mustard (deer photo from Wikimedia Commons, garlic mustard photo by Kate St.John)

Deer and garlic mustard (deer photo from Wikimedia Commons, garlic mustard photo by Kate St.John)

 

If you like native plants you’re probably dismayed by the increase of invasive garlic mustard (Alliaria petiolata) in Pennsylvania’s woods.

Garlic mustard has become more abundant at the same time that Pennsylvania’s deer population has exploded.  Since deer don’t eat garlic mustard, observers assumed the plant’s increase was directly tied to the fact that deer eat natives and not this invasive alien.

But the relationship is more complicated than that.

At October’s meeting of the Botanical Society of Western Pennsylvania, Dr. J. Mason Heberling presented conclusions he’s drawn after studying the interaction of garlic mustard, native plants, and deer from a 13 year experiment at Fox Chapel’s Trillium Trail.

It turns out that garlic mustard likes more sun than it normally gets in Pennsylvania’s summer woods so when deer over browse native plants their shade goes away and garlic mustard thrives.

When deer are excluded native plants grow again, they shade the garlic mustard and it decreases.

Fewer deer?  Less garlic mustard!

Everything is connected, often in amazing ways.

 

For more information, read the study abstract here at Interactions of White-tailed Deer and Invasive Plants in Forests of Eastern North America presented at the Botany 2016 Conference.

(photo of garlic mustard by Kate St. John. photo of deer by josephamaker2018 via Wikimedia Commons; click on the original)

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Dec 04 2016

Funny Face is Flehmen Response

Published by under Mammals

If you have a cat, I’m sure you’ve seen it sniff something and then raise its head with its mouth open as shown in the video above.

This gesture is called the flehmen response or flehmening and it’s how cats inhale and analyze pheromones.

Many mammals flehmen in response to pheromone laden scents. They bare their teeth, close their nostrils and breathe through their mouths to direct the scent into the vomeronasal organ (VNO) located above the roof of the mouth.  In felines, there’s a duct just behind their front teeth that leads to the VNO.

Horses flehmen, too.  When I was a kid there was a TV show called Mister Ed, the Talking Horse, whose face looked like this when he “talked.”

Flehmen response of a horse (photo from Wikimedia Commons)

Flehmen response of a horse (photo from Wikimedia Commons)

Now that I’ve seen this photo, I’ll bet the trainers put an interesting smell under Mister Ed’s nose to provoke the flehmen response.  And they said he was “talking.”

 

(video by Kyle Hayes on YouTube. photo of horse flehmen response from Wikimedia Commons; click on the image to see the original)

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Nov 27 2016

Cars And Deer

Published by under Mammals,Schenley Park

Deer spooked near the road (photo by Mike Tewkesbury, Creative Commons license via Flickr)

Deer spooked near the road (photo by Mike Tewkesbury, Creative Commons license via Flickr)

It’s that time of year again when cars and deer come into conflict.

From October through December white-tailed deer hormones surge for the mating season.  Males become aggressive, spar with their rivals, and challenge anything they see as a threat.  Both sexes roam in search of mates and barely pay attention to their surroundings.  Cars are the last thing on their minds.

Last year, Pennsylvania won the “prize” for the most deer-vehicle collisions in the U.S.   According to a September 2015 article by Ad Crable at Lancaster Online, we hit 127,275 deer with our cars — and those were only the collisions reported to insurance.   When compared to hunting season, which took more than 353,000 deer that year, we’re making a sizable dent with our vehicles.

A case in point is in Schenley Park where hunting is prohibited, as in all Pittsburgh City Parks.  Deer used to be rare but they moved in about 10 years ago (perhaps longer) and their population has exploded in the past five years.  I knew we’d reached a milestone when I saw a first ever road-killed deer in the Park along the Boulevard of the Allies, hit on November 5 or 6.

I’m sure the person who hit that 6-point buck was very, very surprised.  So are those whose dogs are challenged by aggressive deer.  Every year since 2015, a buck has killed a dog in the City’s east end parks.

So be careful out there, especially at dusk and dawn when deer are most active.  Use your brightest headlights and slow down.  Don’t become a statistic.

 

Reminder: Deer (rifle) season begins tomorrow, Monday November 28, in Pennsylvania. Wear blaze orange when you’re outside the city.

(photo by Mike Tewkesbury, Creative Commons license via Flickr. Click on the image to see the original.)

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