A locking mechanism above a flamingo's foot keeps its leg from collapsing as the bird drowses, and the same exquisite sense of balance that lets a wading bird hold its head absolutely level while stalking through a marsh during the day prevents it from toppling over at night.
Do they ever! There are mites that live aboard no- see- ums, the tiny biting flies that are themselves small enough to fly through window screens. Another mite, Acarapis woodi, makes its home in the breathing passages of honeybees.
This opportunistic behavior doesn't suffocate the bees, but it does shorten their lifespans—dooming many a commercial hive in the process. Other bug- bugging bugs are exactly what humans are looking for. In the U. South, armies of fire ants have an inconvenient tendency to chew through electrical insulation inside traffic- light poles, for example. Entomologists at the U. Female Pseudoacton lay their eggs inside fire ants.
The larvae feed on the ants from the inside and finish up by decapitating their hosts. Another internal parasite being tested by the USDA is a nematode worm that digs through the outer skin of aquatic mosquito larvae and makes itself at home. The worm even goes through several molts there, to its host's increasing detriment. More subtle are the social parasites. These are animals that mimic the signals and behavior of high- status hosts—queen bees, for example—as a means of enslaving their oblivious underlings.
One socially parasitic ant, Teleutomyrmex schneideri, is so adept at subjugating the colonies of another ant species that its own hunting and feeding organs have mostly disappeared along with its worker caste. Explains psychologist Howard Topoff of Hunter College, "The parasitic Teleutomyrmex queen spends much of her life riding on the back of the host queen while being fed by the workers of the host species, an ant called Tetramorium caespitum.
Some of the scenarios involving parasitic wasps suggest a Biblical genealogy "Euryptoma beset Mesopolobus, which beset Toryus, which beset Syntomaspis, which beset Cynips, which started the trouble by besetting the gall of Cynipidae". It's a bug- eat-bug world, all right. To quote the poet: Big fleas have little fleas Upon their backs to bite 'em, And little fleas have lesser fleas, And so, ad infinitum. Apparently, even with thousands of hiding places to keep track of, birds try to memorize them all.
Nottebohm's research offers a clue. In a recent experiment, he measured a dramatic jump in the number of new cells in the black- capped chickadee hippocampus—the part of its brain that seems to be involved in spatial memory.
The peak in the recruitment of new cells, which replace older ones that die, comes around October each year, just when the bird's seed- caching is at its most furious. He speculates that the new brain cells are better able to acquire new memories. Captive chickadees don't show the same cell growth. Nor do humans, alas, regardless of their situation. Moreover, says Nottebohm, "The hippocampus of birds that hide food is larger than that of birds that don't.
Probably no creature can match the impressive growth of the ocean mola also known as the sunfish. A full- size sunfish can stretch 10 feet and weigh 1, pounds, which is some 60 million times what it weighed as a hatchling.
The egg it emerged from was about the size of this o. As for live- born animals, the champion is surely the red kangaroo. Hissing is primarily used as a last resort before a full-blown attack. But this serpent-like sound can also serve other purposes, such as establishing dominance in a hierarchy or intimidating a prey animal. It is a low-intensity sound that a big cat will emit in short, loud bursts.
To vocalize a chuff, air is blown through the nostrils while the mouth is closed, producing a breathy snort. It is typically accompanied by a head bobbing movement. It is often used between two cats as a greeting, during courting, or by a mother comforting her cubs. Chuffing is always used as a non-aggressive signal and helps to strengthen social bonds. Surprisingly, meowing is not expressly reserved for domestic cats. Snow Leopards, Lion cubs, Cougars, and Cheetahs also meow.
Meowing can be used to locate each other or simply a request for food or affection. All of this may sound extremely arbitrary, but the animal kingdom is heavily reliant on classification as a method of study. If lions and leopards make a fundamentally different noise to a household cat's purr, then they shouldn't be treated as the same kind of sound because they probably evolved differently.
So, according to present knowledge , "true" purring is established only in the families Felidae, which includes small cats, and Viverridae, a family of medium-sized mammals. While big cats do make noises that sound similar, they seem incapable of purring in the true sense.
If we want to figure out what makes a "true" purr true, however, we need a closer inspection of cat species acoustics. And figuring out what's going on inside a cat's throat while it makes a noise is extremely difficult, not to mention dangerous. Home Animal Facts Mammals Why can only big cats roar? Roaring tiger. A growling or roaring leopard. Roaring jaguar.
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