22 January 2016
One autumn evening in Sweden, a man came home from his nighttime job and heard a strange bellowing in the dark coming from his neighbor’s apple tree.
A drunken moose was calling for help!
To rescue the moose they had to chop down the tree.
p.s. The moose had been eating fermented apples. And that’s why the apple tree came down.
(video from YouTube)
On Throw Back Thursday:
The news from Flint, Michigan about lead in their water supply reminds me that I wrote about lead poisoning in birds back in 2009. Sadly not much has changed.
Though the U.S. has banned lead shot in wetlands, it’s still present in fishing sinkers and the bullets used in deer hunting. Scavenging birds, including bald eagles, eat the gut piles hunters leave behind and are poisoned by the bullet fragments. Many die.
A 2012 bald eagle mortality study in the Upper Mississippi Valley found that 60% of the dead eagles had detectable concentrations of lead in their livers. 38% had lethal levels.
Sadly, the problem is seen too often by veterinarians and wildlife rehabilitators.
Back in January 2009 I wrote about the dangers of lead poisoning and the sick eagle, pictured above, who was treated at Medina Raptor Center, Ohio. Learn more in this 2009 blog post: Lead Poisoning
(photo from Wikimedia Commons. Click on the image to see the original)
p.s. Last year California became the first state to ban lead in bullets. They are phasing them out over a period of five years.
20 January 2016
This week I blogged about a caracara on a capybara but I didn’t tell you much about the bird. Why was the bird standing on the mammal? Hint: The falcon’s nickname is “tickbird.”
Yellow-headed caracaras (Milvago chimachima) are omnivorous members of the falcon family who live in south-Central and South America. They eat almost anything — carrion, frogs, fish, eggs, palm fruit, corn, horse dung — but when it comes to feeding their young they focus a lot on insects. 90% of the nestlings’ diet consists of beetles, grasshoppers and crickets.
They earned their nickname “tickbirds” because they also glean ticks off of cattle and other mammals, including capybaras. Above, a juvenile yellow-faced caracara cleans a cow. The cattle don’t mind, even when the caracaras pick at open wounds.
Yellow-headed caracaras have adapted well as the forest is converted to ranches and cities. You’d never guess from this video that their nickname is The Tickbird.
(videos from YouTube)
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19 January 2016
A hawk perched on a pig? Well, almost. A caracara on a capybara.
The bird is a yellow-headed caracara (Milvago chimachima), a member of the falcon family native to South America(*) and similar in size to a Cooper’s hawk.
The mammal is a capybara (Hydrochoeris hydrochaeris), the world’s largest rodent. Its scientific name is Greek for “water pig.” Its English name means “eats slender leaves” in the extinct Tupi language of Brazil.
Semi-aquatic, vegetarian, and closely related to the guinea pig, capybaras swim a lot. They eat grass and aquatic plants which fortunately wear down their continuously growing teeth. They also eat their own feces to get more nutrition out of their partially digested food.
Capybaras are big. They stand as tall as a German shepherd but of course they’re not the same shape and they weigh a lot more. For a sense of scale, here’s a group of capybaras grazing in a park in Brazil.
These groups are typical. Capybaras are very social and live with 10-20 and up to 100 other individuals. The round bump on their snouts is a scent gland called a morillo which they rub on everything to say “I’m here.” They also use anal scent glands and urine for the same purpose. Obviously capybaras do not make good pets.
As for the bird, why is the caracara on the capybara?
(photos from Wikimedia Commons. Click on the images to see the originals.)
(*) Both the bird and the mammal have expanded their range into southern Central America.
Though January is gray and cold, peregrine falcon courtship has begun. Watch the skies near any of Pittsburgh’s nesting sites and you’re likely to see peregrines in courtship flight. It’s a breath-taking display that ends at the nest.
If you miss them in the sky you can see them on camera at the falconcam sites as they perform another part of their courtship: ledge displays.
Above, Hope and E2 “chirp,” bow low, and turn their heads side to side as they court at the Cathedral of Learning nest on Saturday, January 16.
Below, Louie entices Dori to visit the Gulf Tower nest on Thursday, January 14. I hope she takes his hint and starts to make a scrape in the new gravel.
Click on each image to see the streaming video at the nest.
Love is in the air right now. Watch for eggs in mid/late March.
(photos from the National Aviary falconcams at University of Pittsburgh and Gulf Tower)
17 January 2016
Blue jays mimic the sounds of raptors to warn or fool(!) other blue jays.
In Pittsburgh they often mimic red-tailed hawks. In Florida they mimic the red-shouldered hawks that are louder and much more common.
This video from MyBackyardBirding in Florida is a good example of how blue jays can sound like hawks. Can you tell who’s who when they aren’t on screen?
The mourning dove seems to be having a hard time figuring it out.
(video from MyBackyardBirding on YouTube)
They look like canaries, don’t they?
In Spanish the yellow ones are indeed called canaries “Canario,” yet all three are in the tanager family (Thraupidae), the second largest family of birds in the world.
Barloventomagico photographed them at El Cedral Ranch in southern Venezuela on December 30. Here’s who they are from left to right: Spanish, (Scientific name), English:
Though they’re tanagers they aren’t related to ours at all. Our familiar scarlet, summer, western and hepatic tanagers (Piranga) are now in the Cardinal family (Cardinalidae).
What a confusion of names!
(photos by barloventomagico via Flickr, Creative Commons license. Click on the image to see the original.)
p.s. A special shout out to Dr. Tony Bledsoe at the University of Pittsburgh! His work on Sicalis DNA in the late 1980s proved that Sicalis are tanagers — published in The Auk (105: 504-515) in July 1988 as: Nuclear DNA Evolution And Phylogeny of The New World Nine-Primaried Oscines.
During the snowy owl irruption two years ago, John Dunstan recorded this video of a raven and a snowy owl having a conversation.
The raven says many things. The snowy owl is unimpressed.
Notice at 1:20 in the video that the top of the raven’s head seems to grow “ears.” This dominance gesture means “I’m big! Watch out!” The owl doesn’t care and reaches over to peck the raven at 1:44. The raven’s ears go down … but up again at 2:09. What’s going on?
John Dunstan asked raven expert Bernd Heinrich, author of The Mind of the Raven, for an explanation and put Heinrich’s reply in the video description:
Naturalist Bernd Heinrich, author of “The Mind of the Raven”, was nice enough to provide this description.
Hi John,
The first thing to notice is that the owl is TOTALLY unimpressed. It’s not scared in the least, and the raven has no aggressive intentions, but starts out being just curious – like: “what the hell is This!” So it tests – tries to get a reaction. But the owl still stays totally nonchalant. At some point the raven then tries a different tactic – it puts on its “I’m a big guy” display of erect “ear” feathers – usually used to show status in the presence of potential superiors, but here used also with a bowing and wing-flaring, which is used in supplication if there is NOT going to be a challenge – so, yes, I think the raven was having fun, and then also starting to have some respect, because this big white thing was NOT going to cooperate and be its toy.
Bernd
The comments on the video are priceless! Click here to see the video on YouTube and read the comments.
(video by John Dunstan on YouTube)
Coming this month is the lecture I’ve been waiting for. On January 27 I’ll learn how NASA finds water using satellites instead of this old method of dowsing with a forked stick.
Since 2002 NASA’s paired GRACE satellites have been circling the globe measuring Earth’s gravitational pull. What they’ve also discovered is a way to measure groundwater.
How do they do it? Learn more here in my January 2014 blog post: Dowsing From Outer Space.
Want to know more?
Come to the University of Pittsburgh Honors College lecture entitled:
Monitoring Groundwater Variability from Space
by Dr. Matthew Rodell, Chief, Hydrological Sciences Laboratory, NASA Goddard Spaceflight Center
When: January 27, 2016, 4:00 PM
Where: Alumni Hall, Connolly Ballroom, 4227 Fifth Ave
The lecture is free and open to the public but space is limited. Click here for more information and to reserve your seat.
(photo of George Casely dowsing on his farm from Wikimedia Commons. Click on the image to see the originals)
During our strangely warm and “yo-yo” winter it’s interesting to realize we’re not the only ones affected by this year’s El Niño. The Galápagos Islands in the Pacific Ocean, 620 miles west of South America, are having a much wilder time of it.
Though located on the equator the Galápagos have a cooler and drier climate than you’d expect because of an important ocean current and the prevailing wind.
The Equatorial Undercurrent (also known as the Cromwell Current) is a wide river of cool water moving west to east from Indonesia to South America, 300 feet below the surface. Because the Trade Winds blow east to west they push surface water away from the archipelago’s western shore. When the Equatorial Undercurrent reaches the islands it wells up to fill the surface void and effectively lowers sea surface temperatures west of the islands (see map above).
Cold water is good. It supports more phytoplankton (tiny chlorophyll-producing organisms) than warm water and that supports the entire food chain all the way up to seabirds, mammals and unusual reptiles: blue-footed and red-footed boobies, Galápagos penguins, Galápagos fur seals and marine iguanas to name a few.
As proof that cold water is good, the map above shows that Galápagos penguins live where the water’s cold. That’s where the fish are.
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El Niño changes everything. The trade winds subside or change direction, the undercurrent no longer wells up and sea surface temperatures rise. The warmth causes a drop in nutrients and the entire food chain suffers. Fish populations drop. Seabirds, mammals and, yes, penguins starve.
This year’s El Niño began forming in mid 2014 and was even then so intense that seabirds were starving off the coast of Chile in June 2014. (see photo on the ABA Blog)
However, something good does comes of El Niño. In the Galápagos there’s a population boom among land-based birds. There, the rainy season is the breeding season and El Niño brings rain, sometimes quite a lot of it. During the strong El Niño of 1982-83, cactus and Fortis finches (Darwin’s finches) bred like crazy, increasing their populations by 400%.
While immensely bad for some species, it’s very good for others.
That’s what El Niño means for the Galápagos.
(map from Climate.gov blog, El Niño and the Galápagos. Photo of Galápagos penguin from Wikimedia Commons. Click on the images to see the originals.)
For more information see these sources:
* The Beak Of The Finch by Jonathan Weiner, especially pages 100-104.
* Climate.gov Blog: El Niño and the Galápagos by Kris Karnauskas.
* Climate of the Galápagos Islands by Chris Ader, University of Maryland