Using underwater microphones they recorded dolphins’ voices and discovered that each one had his own unique whistle, a signature sound. Having matched the signatures to individuals they then played back the sounds, one at a time. The dolphin who “owned” the sound responded.
This is just like what humans do. If you call out “Kate,” I’ll respond — if I hear you.
Hearing is probably the reason why dolphins have named themselves. They live in a world where it’s hard to see but easy to hear (sound travels better in water than in air). They also live in a social group that’s always on the move. When a friend has swum out of sight they call him and the friend answers. This makes it easy for the group to stay together.
Researcher Vincent Janik points out that individual communication is also important for mothers and calves. Baby dolphins rely on their mothers’ milk until they are three years old yet they’re just as mobile as their mothers. What an advantage that they can call each other by name!
In the arctic where day and night last for months a circadian rhythm would be annoying if not a handicap. Since “day” has no meaning, arctic reindeer solved the problem by turning off their internal 24-hour clocks.
In mammals the circadian rhythm causes melatonin levels to rise at night and fall during the day. This happens whether or not the sun gives us a cue.
Scientists studying reindeer in Norway (Rangifer tarandus, the same species as caribou) found that they have no rhythmic melatonin cycle. Instead their melatonin rises or falls abruptly in response to light. On or off. No daily clock.
Reindeer need to know the time of year so they can synchronize migration and breeding, but this is easy to do at the equinox when the sun rises and sets.
On Svalbard where this reindeer lives, the sun rose on April 16 and won’t set until August 27.
No wonder he doesn’t care what time it is. Some days I wish I didn’t care either.
When I saw this cute photo by Meredith Lombard I knew I had to write about baby porcupines but I soon learned that the truth about these rodents is stranger than fiction.
For starters, baby porcupines are called porcupettes.
Each porcupette is a precocial only child, born with open eyes, well formed teeth, a full coat of fur, and able to climb trees a few hours after birth. In only two weeks he eats green plants. In three months, he’s weaned.
Like his parents he has three kinds of fur: a woolly undercoat, long coarse guard hairs, and sharp hollow quills with barbs at the tip that slant backward. When born his quills are soft and harmless (good thing for his mother!) but within half an hour they’ve stiffened into the protective coat that saves his life. The only place he doesn’t have quills is on his belly — just like his parents.
Neither he nor his parents “throw” their quills but the quills are so loosely attached that they stick easily to any critter that comes close. That includes dad when he approaches mom to conceive a porcupette. Needless to say copulation is a very careful business. No hugs are involved, but there’s a lot of courting to get her in the mood. Dad whines and dances on three legs, showing her his equipment. When she says “You’re the one” he showers her with urine. Then they mate.
I’m not kidding.
All of this happens in October or November. Seven months later: a porcupette.
It used to be that wild animals avoided human contact but that’s not true in Pittsburgh anymore. We have hawks, wild turkeys, foxes and deer in the city. Not every animal can cope with city life but the individuals who can tolerate close human approach are doing quite well in our parks and cemeteries.
Sharon Leadbitter visits Allegheny Cemetery often and frequently saw this doe and fawn last summer. They weren’t tame but they learned that Sharon isn’t dangerous. This was reinforced for the fawn every time it met a human and Mom said “It’s ok.”
Fawns are born in May in Pennsylvania so by now this baby is an adult and it’s mother has a new fawn. I’ll bet this doe will let Sharon meet her new fawn, too.
And there will probably be four deer this year. This doe plus her new fawn, and this fawn (now an adult) plus her fawn. That’s how easy it is to end up with a lot of deer.
Nature observers and webcam lovers, here’s an opportunity to go on a virtual safari and contribute to science from the comfort of your home.
The University of Minnesota has been studying lions in Africa’s Serengeti for over 45 years. Several years ago, in an effort to determine the population of other species in lion country, they installed 225 motion-detection cameras to record all the animals, both day and night, that pass by the study sites.
They now have thousands and thousands of photographs that contain an animal of interest … but which animal? And how many? And what are they doing? Are there Wildebeest? Zebras? Serval cats? Eland? Guinea fowl? Grant’s gazelles (above)?
The task of identifying and counting the animals in so many photos was too huge for just a few people so they teemed up with Zooniverse to launch the Snapshot Serengeti website. It’s a citizen science project and you can help.
Visit snapshotserengeti.org to see the photos. Try the tutorial. Learn how to identify the animals and how to use the clues for animals you’ve never seen before. Then checkmark three items: what species, how many, what they’re doing. Click Finish and you’re onto the next photo.
Of the two Zooniverse projects I’ve tried so far I like this the best. At first I wasn’t very good at wildebeest vs. eland vs. buffalo but I quickly got better. I could really tell I’m a “bird person” when I was excited to see two guinea fowl, and then a secretary bird!
Somehow I missed Raccoon Nation! when it premiered on PBS NATURE last February but Oh, my! I watched it online last week and I can hardly wait to see it on the big screen when PBS re-broadcasts it on Halloween.
I’ve already learned that raccoons are the smartest animal in the urban jungle. They’re relatively small (so it’s easy to hide), nocturnal, omnivorous and adaptable. They learn from their mothers and they can get into anything because they have thumbs.
I’ve seen this in my city neighborhood: a mother raccoon guiding her kits to shelter, the sound of racoons arguing over my neighbor’s bird feeders at night, the shadows of ‘coons raiding my bird bath.
There’s not a garbage can they can’t open. They’re ready for any challenge. And our attempts to outsmart them make them smarter!
So of course I’m going to pull up a seat on Wednesday October 31 at 8:00pm and watch Raccoon Nation! in living color on WQED.
I can hardly wait. On Halloween the animals will wear masks.