Posted on November 26th, 2010 No comments
One last Thanksgiving-related question, since Friday is still a holiday for some of us.
There are two correct answers to this, but only one was mentioned by Twitter correspondents. The first correct answer was from @little_mavis: The guinea pig is a species domesticated in the New World but given an Old World name.
Guinea pigs (Cavia porcellus) are called “pigs” (commonly and scientifically) because of their pig-like build and the pig-like sounds they make. They were first domesticated in mountainous regions of northwestern South America. Why they are called “guinea” pigs is a matter of conjecture, and may be a combination of several factors. One hypothesis is that “guinea” is a corruption of Guiana, though they’re not originally from there, either. Another guess is that “guinea” pigs may have been imported to Europe via Guinea (West Africa) and so been named for the wrong place.
The misnaming of the “guinea” pig may simply be similar to the misnaming of the turkey. It may have been intentionally named for an exotic-sounding place, even though that place is not where the animal actually came from.
A third species first domesticated in the New World and given a misplaced name is the muscovy duck (Cairina moschata). It’s not from Muscovy, but from northern South America and possibly Central America.
The muscovy duck is the only breed of domestic duck not descended from the mallard (Anas platyrhynchos). Most domestic ducks are descended entirely from the mallard, but a few from hybrids of mallard and other Anas species. In fact, transgeneric hybrids of muscovy ducks and mallard-derived ducks can be bred, but the hybrids can not reproduce. They are often raised for meat because they grow quickly, like mallard-descended domestic ducks, but grow to be larger, like the slower-growing muscovy duck.
The muscovy duck may have derived its name from incorrect association with Muscovy (the duchy that includes Moscow), or from their musky odor. The scientific name Cairina moschata means “musky one from Cairo,” but the muscovy duck is not from Cairo, either.
More about New world domesticates with Old World names:
Posted on November 23rd, 2010 No comments
First correct answer was from @arachne182: The fleshy protuberance above a turkey’s beak is called the snood.
Many galliformes (grouse/quail/pheasant family) have elaborate head decorations, but the snood is probably unique to the turkeys. Both male and female turkeys have snoods and other head decorations (wattles and caruncles), but all of these decorations are larger and more colorful in the males.
Turkeys can raise and lower the snood at will, but it serves no function other than display.
More about turkeys: http://en.wikipedia.org/wiki/Turkey_(bird)
Posted on November 17th, 2010 No comments
First correct answer was from @KessCat: The giant river otter (Pteronura brasiliensis) it the largest member of the weasel family by length.
The sea otter (Enhydra lutris) is often named among the largest mustelids. Individuals vary greatly, and the species overlap in size (i.e. the longest sea otter is longer than smallest giant river otter), but the giant river otter takes the record as the longest mustelid. The longest giant river otters measure about 5.9 feet. Sea otters reach just about 5 feet. By weight, the sea otter and giant river otter reach about the same size: 100 lb. or so at the most.
Many people mentioned the wolverine. The wolverine (Gulo gulo) is the largest land-dwelling mustelid, but only about 4 ft long and 55 lb. at the largest.
More about the biggest weasels:
What is the most widespread _wild_ freshwater fish in the world? (Spread mostly by human agency, of course.)Posted on November 8th, 2010 No comments
(This is the question I intended to ask on Friday, but “goldfish” was the correct answer to that question as originally worded. Now, what is the most widespread non-domesticated freshwater fish?)
There were no correct answers to this one. The western mosquitofish (Gambusia affinis) is probably the most widespread freshwater fish in the world.
There was a small clue in yesterday’s discussion of goldfish, but mosquitofish are even more tolerant of marginal habitats than goldfish. Mosquitofish can tolerate a wide variety of habitats, and they feed on larval mosquitos. They have been introduced for mosquito control, even more frequently than goldfish have been. Mosquitofish can live in salt water, so once introduced, they spread to nearby rivers and soon permeate whole watersheds.
Although often effective at controling mosquitos, the introduction of mosquitofish often harms native fish and other aquatic species.
The mosquitofish introduced and causing environmental havoc near Brisbane, Australia, is not the western mosquitofish (Gambusia affinis), but the closely related eastern mosquitofish (G. holbrooki).
More about mosquitofish: http://en.wikipedia.org/wiki/Gambusia_affinis
What is the most widespread freshwater fish in the world? (Spread mostly by human agency, of course.)Posted on November 5th, 2010 No comments
First correct answer was from @mlv: The goldfish is the most widespread freshwater fish in the world. Honorable mention to @KessCat for suggesting carp. The carp family (Cyprinidae) includes goldfish and many other widespread species.
Goldfish (Carassius auratus auratus) are the earliest fish to be domesticated, and are probably the most commonly kept aquarium fish. Besides being widely kept in captivity, there are wild-living populations of goldfish on every continent except Antarctica.
Like many domestic animals, goldfish readily revert to a wild state, and return to their ancestral appearance within 3 generations. Wild-living goldfish can breed among themselves, or crossbreed with related carp species. Goldfish are sometimes introduced to the wild for mosquito control due to their tolerance for stagnant water and wide range of temps. Like any introduced species, goldfish can harm ecosystems by outcompeting native species.
More about goldfish: http://en.wikipedia.org/wiki/Goldfish
How do larvae of monarch and related butterflies avoid getting their jaws gummed up by the sap of milkweed plants?Posted on November 2nd, 2010 No comments
No correct answers to this one. Monarch butterfly caterpillars (and relatives) cut the veins of leaves before feeding to avoid gummy sap.
When very small, the caterpillars simply feed on the surface of the leaf, then move to a different spot when the sap begins to flow. Sometimes they do get their jaws stuck in the latex-rich sap, and caterpillars often starve as a result.
When they grow large enough, the caterpillars cut a vein near the base of the leaf, then eat the part that has been cut off from sap. All the latex that the plant exudes to try to repel the attack leaks out through the cut vein, and the caterpillar can feed in safety. This technique allows monarch and related caterpillars to feed on milkweed leaves despite their sticky, gummy sap.
Besides coping with sap that would glue their jaws shut, monarch caterpillars must also tolerate toxins within milkweed leaves. They do this successfully, and even incorporate the toxins into their own tissue, rendering the caterpillar and the butterfly that develops from it toxic to predators.
More about monarch butterfly caterpillars: http://en.wikipedia.org/wiki/Monarch_(butterfly)
What fish produces a neurotoxin which some researchers claim to be part of the process of creating zombies?Posted on October 29th, 2010 No comments
First correct answer was from @jrechs: Blowfish (or pufferfish) produce a neurotoxin which hypothetically creates zombies.
Tetrodotoxin (TTX) is a powerful and frequently fatal neurotoxin found in the flesh of the pufferfish (order Tetraodontidae).
There is a hypothesis proposed by Dr. Wade Davis of Harvard University, an idea that is not universally accepted, that Haitian Vodou practitioners create “real zombies” using TTX and other toxins. According to this hypothesis, the victim enters a near-death state, is buried, then reanimated as a slave of the zombie-maker. Part of this hypothesis is that the “reanimated” victim is psychologically predisposed to behave as a zombie due to cultural beliefs.
Many victims of accidental TTX poisoning, mostly in Japan where pufferfish is sometimes eaten, report that they remained fully aware of what was going on around them, able to hear, and sometimes even to see, when they were thought to be in a deep coma or near death. This is consistent with the reports of some Haitian “zombies,’ saying that they were aware of who was at their funerals, they remember being buried, and that the vodou practitioner later exhumed and revived them to be slaves.
Some critics claim that Davis might be a bit too gullible in taking the “zombies'” claims too seriously.
More about pufferfish and zombies: http://en.wikipedia.org/wiki/Zombie#Zombies_in_Voodoo
Posted on October 28th, 2010 No comments
No fully correct answers to this one. Bats’ lungs are thought to be more susceptible to damage from pressure changes than are those of birds.
As @mlv suggested, rapid changes in air pressure near wind turbines can rupture the lungs of bats, but why not birds?
And @paulsmoffett suggested an alternate hypothesis that wind turbine blades are harder to “see” via ecolocation than via eyes. This suggests that bats may accidentally fly close to the moving blades more often than birds do, simply because the bats are not aware of the blades.
Birds and bats are often found dead near wind turbines with no visible trauma. It is thought that changes in air pressure ruptures lungs. When the bird or bat flies very near the moving wind turbine blade, changes in air pressure can burst or collapse the lungs.
As a proportion of local population, more bats die near wind turbines than do birds. The “barotrauma” caused by changes in air pressure is thought to affect “dead end” mammal lungs more than the complex bird lungs. A bat’s lungs, like a humans, have only one airway in and out, so changes in pressure have no escape route. A bird’s lungs have two airways in and out, one connected directly to the nose and mouth (like a mammal’s airway), and the other connected to the “air sac” behind the lungs and to the air spaces within the bones. It is thought that the more complex respiratory system of a bird provides better pressure relief than a bat’s dead-end mamallian system.
More about bat/bird mortality near wind turbines: http://en.wikipedia.org/wiki/Bat#Wind_turbines
Not quite werewolves, but there is a special connection between black wolves and domestic dogs. What is it?Posted on October 27th, 2010 No comments
First correct answer was from @paulsmoffett: The canid gene for black coats is thought to have originated in domestic dogs.
At various times and in various places, black wolves were classed as separate species from their gray counterparts. In many cultures, black wolves are considered more vicious and less likely to avoid humans, so they are “spookier.” It is now known that black wolves are just color morphs of the same species (Canis lupus) generally called gray wolves.
Black coat color was also recorded in the red wolf (C. rufus), but it is now considered absent from that species.
(Actually I have a back-burner project to write a series of articles about the complex and controversial genetics of the red wolf and its connection to the “eastern coyote.” I once saw a creature that was black, and I say it was a wolf in all aspects but one, and it was in an area where C. lupus has been absent for nearly 200 years, and not very far from a know population of C. rufus. It was not a coyote. It was a wolf. Okay, it held its tail down when it ran, in coyote fashion, but it was a wolf in all other respects.)
At least one genetic study suggests that the mutation for black fur originated in domestic dogs, and then was transferred to wolf populations. If this study is correct, all black wolves are descendants of at least one domestic dog. An alternate hypothesis is that the gene for black fur may have originated in Eurasian wolves, but been transmitted to North American wolf populations via domestic dogs.
The same gene causes black fur in dogs, wolves and coyotes, and it is thought to have entered both wolf and coyote gene pools via domestic dogs.
In any case, the gene for black fur is thought to have originated about 46,000 years ago, when there was little difference between wolf and dog. Cross-breeding between wolves and dogs was probably much more commonplace at that time than it is now, and it is not at all unknown even now.
More about black wolves: http://en.wikipedia.org/wiki/Black_wolf_(animal)#Genetics_and_ancestry
What is a leading killer of bats in northeastern North America, threatening species with extinction?Posted on October 26th, 2010 No comments
First correct answer was from @KessCat (@KessBat?): Bats in northeast North America are dying from a mysterious white fungus.
The “white nose syndrome” fungus is killing whole roosting colonies of bats, threatening some populations with extinction. White nose syndrome got its name from white fungal growth on the muzzles and wings of infected bats. The fungus is called Geomyces destructans.
White nose syndrome has been found in bat colonies from Oklahoma and Tennessee to Ontario and Quebec. The fungus only grows in cold conditions, so it kills bats while they hibernate.
It is not certain that the “white nose syndrome” fungus is the direct cause of mass bat fatalaties, or an opportunistic infection that grows on bats that are already terminally sick.
“White nose syndrome” fungus has also been identified in bats in France, but they were not sick. There are interesting implications. This may mean that white nose syndrome originated in Europe, and European bats have some resistance to it. It may also mean that white nose syndrome is not the actual cause of these mass deaths, and the actual cause is not present in Europe.
More about white nose syndrome: http://en.wikipedia.org/wiki/White_nose_syndrome