No. He could eat them if he wanted to but these barbell fish are his helpers. They eat ticks from his skin and food from his teeth. It's a symbiotic relationship.
The hippo and the barbell fish are just one example of the unlikely partnerships animals make with other species. Watch the premiere of Nature's Perfect Partners on Wednesday May 11 to learn about many more -- lizards with lions, a fish with a blind shrimp, toads with tarantulas.
Tomorrow is the mid-point of winter, halfway between the winter solstice and the vernal equinox. February 2 is also the day when a very special rodent, Punxsutawney Phil, emerges from his den to predict the weather for the next six weeks.
Phil never makes his prediction in isolation. His day in the sun (or shade) spawns a huge celebration in Punxsutawney, PA. Preview the excitement in his eight minute promo video above.
If you don't like winter, then hope for an overcast sky so that Phil has a day in the shade. Here's why.
Did you know there's a whale with a horn like a unicorn?
The narhwal (Monodon monoceros) is an arctic whale, closely related to the beluga whom it resembles.
Like the beluga, it has teeth though it doesn't use them for chewing. All but two of the teeth are vestigial but one of those, the left canine, grows though the male's upper lip spiraling counter-clockwise, straight out, in a single tusk as much as nine feet long.
The tusk is not a sword. Instead, like our teeth it's made up of layers but it's hollow inside and much more sensitive. The outer layer is permeable, allowing seawater to pass through the dentin into the hollow core filled with millions of nerves. Scientists know the tusks can sense salinity but they probably can sense a lot more. When narwhals surface to breathe and rub tusk to tusk they're not fighting, they're communicating.
Narwhals are so specialized it may lead to their extinction. They live only in the Arctic Ocean where they depend on its icy habitat for food and shelter. They roam in pods of 5-10 individuals and may migrate in groups of 1,000 but they seem more loyal to their favorite sites than to following their food. As climate change heats the water and melts the arctic ice, narwhals will have less food and fewer places to live. Like the polar bear, narwhals are threatened by climate change.
If or when this whale goes extinct it may pass into mythology, like the unicorn.
(photos from Wikimedia Commons. Click on the images to see the originals)
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?
More on that tomorrow.
(photos from Wikimedia Commons. Click on the images to see the originals.)
(*) Both the bird and the mammal have increased their range into southern Central America.
Are humans the only species that fools others to survive, find food, and mate? Not at all!
This month PBS NATURE premieres a new three-part series, Natural Born Hustlers, airing on PBS on Wednesdays, January 13, 20 and 27 at 8:00pm (ET) (check local listings).
Episode One, Staying Alive, focuses on survival techniques: camouflage, dominance tricks, audio mimics and playing dead. Early on I was amazed to learn how zebras' stripes create an optical illusion. You have to see them in motion to believe it!
Other fascinating finds are the amazing skin-morphing camouflage of cuttlefish, the lizard that walks like a stinky beetle, and the white-faced capuchin monkeys who calculate whether they're needed in battle. "More capuchins are killed by their own kind than by predators," says the episode. What an unfortunate trait to have in common with humans.
The video excerpt above gives you a good idea of animals' ingenuity. California ground squirrels use their enemy's scent as protective camouflage. Their arch enemy is the rattlesnake, so if you hate to look at snakes this video will make you flinch.
And fair warning to those afraid of snakes: Staying Alive has quite a few snakes in it including a match-up in North Carolina of a harmless species that mimics the coral snake. The bonus is that you can identify birds by song on the audio track.
This month I hiked the Wetlands Trail at Raccoon Creek State Park in Beaver County where I found many small trees chopped down next to Traverse Creek lake. Across the water, cut treetops and shrubs lay in a messy half-submerged brush pile against the opposite shore.
The stumps don't show the straight-edge cut of human activity. If you look closely you see tooth marks. Big incisors were at work.
When Beaver County was named for the Beaver River in 1800, their namesake was already hard to find. The North American beaver population was 100 to 400 million before Europeans arrived to trap them but 300 years of over-hunting took its toll. According to the PA Game Commission, "the last few beavers known to naturally exist in Pennsylvania were killed in Elk, Cameron, and Centre counties between 1850 and 1865."
Game laws and reintroduction programs have brought beavers back to 10% of their former population. Today there are 10 to 15 million beavers in North America.
In Pennsylvania one indication of the beavers' success is the number of complaints they generate, mostly about flooding including plugged culverts and flooded roads. A lot of complaints often means there are a lot of beavers.
Here's news that surprised me about white nose syndrome, the disease that's wiping out bat populations in eastern North America.
White nose syndrome (WNS) is caused by a cold-loving fungus, Pseudogymnoascus destructans, that thrives in temperatures 40-200 C (390- 680 F), which happens to be the winter temperature in caves where bats hibernate.
The fungus attaches to the bat's exposed skin -- nose, wings, ears -- where it looks like white powder. It doesn't kill bats directly. Instead it eats away at their skin, causing irritation, dehydration, and higher metabolism that burns up their fat stores.(*) The bats rouse themselves and fly around on mid-winter days looking for food. There aren't any flying insects to eat so they starve and die. Millions of them.
Bat researchers are now in a race against time to stop the fungus. Meanwhile they found out where it came from: Europe.
How did it get here?
In The Sixth Extinction: An Unnatural History Elizabeth Kolbert describes its probable path as told by NY DEC's Al Hicks. The first record -- in 2006 -- was photographed in "a cave connected to Howes Cave, a popular tourist destination which offers, among other attractions, flashlight tours and underground boat trips. "It's kind of interesting that the first record we have of this is photographs from a commercial cave in New York that gets about two hundred thousand visits a year," Hicks told me."
And so it's likely that someone with spores on their clothing or gear got on a plane in Europe and visited a cave near Albany.
It's amazingly easy to introduce an alien invader.
(photo by U.S. Fish and Wildlife via Wikimedia Commons. Click on the image to see the original)
Acorn abundance varies every year. Some years there are lots of acorns, other years not so many. This variation is an oak survival mechanism that alternately floods and dries up the market to insure that some of their nuts survive hungry predation by squirrels, turkeys and deer.
Back in December 2008 there were so few acorns in the Washington, D.C. area that the situation made national news and people put out store-bought delicacies for squirrels.
Were the squirrels begging for attention? Click here to read this 2008 article: The Acorn Plot.
p.s. Pennsylvania's squirrels have nothing to worry about this winter and next. The PA Game Commission says the acorn crop will be abundant this year and in 2016. Click here to read more.