Stupid Question ™
June 19, 2003
By John Ruch
© 2003
Q: Does every species have an albino variation?
—Anonymous
A: Albinism generally refers to an abnormal lack of pigmentation in the skin, fur, feathers, eyes, etc. So obviously it does not occur in species, including myriad bacteria, that have no pigmentation whatsoever.
There are also a few uncommon species, such as the cavefish, that are essentially albino and thus have no albino variation.
Albinism is a function of abnormal pigmentation cells. Therefore, it doesn’t affect creatures whose dominant coloration comes at least in part from other sources. Albino insects are virtually unknown, apparently because their coloration often depends on the natural color of their shells, not from pigmentation cells within it.
As a final caveat, it is of course impossible to determine whether every single species on Earth has an albino variant (it being hard to define “species” anyhow).
All that being said, albinism of some type has certainly been seen in virtually all well-known vertebrates—gorillas, peacocks, giraffes, moose, lemurs, zebras, carp, alligators, tree frogs, whales, raccoons and penguins among them.
Albinism is also seen in plants, including wheat and barley and a variety of trees: spruce, buckeye, birch and aspen. These are much more rare than albino animals because plants rely on their pigmentation—chlorophyll—to produce food in a reaction with sunlight, and die rapidly without it. (It can occur non-fatally in specific areas, such as flower petals.)
Plants are genetically bizarre and can pull off the trick of being an albino/pigmented hybrid—for example, an albino stem giving off pigmented shoots. The reddish and yellowish cacti commonly sold across the country are a lab-created hybrid of normal and albino plants.
“Albinism” is a dangerously generic term and can lead to the mistake of thinking that all albino animals look the same, for the same reasons. In fact, albino snakes and frogs are usually yellowish, and most “white tigers” still have light brown stripes.
Only human albinism has been thoroughly studied. There are two main types, one involving an overall lack of the pigment melanin, and the other only a lack of eye melanin. (Albinism can also be a symptom of larger syndromes.)
The actual level of pigmentation can vary widely. (Most people with albinism have blue eyes, not reddish as is commonly believed.) In fact, the only definitive post-natal test for albinism is an eye test—the lack of pigmentation causes a birth defect in the formation of the eye, for reasons still unknown.
Things get even more complex in non-mammalian species. Reptiles, for example, have three types of pigments. One or more can be abnormal. Herpetologists use “albinism” to refer specifically to a lack of melanin, which may not affect a reptile’s overall coloration much at all.
In extremely rare cases, reptiles may have low levels of all three pigments and appear totally white, which you and I would call “albinism” but is known academically as “leucism.”
Showing posts with label animals. Show all posts
Showing posts with label animals. Show all posts
March 28, 2008
Crows Collecting Shiny Objects
Stupid Question ™
Nov. 7, 2002
By John Ruch
© 2002
Q: Why do crows collect shiny objects?
—Gingerkitten Telekinesis
A: If you root around in a crow’s nest expecting to find an avian Aladdin’s Cave of gold watches, coins, rings or even bottle caps, you will be sorely disappointed.
Crows, ravens and magpies—all similarly accused of this superficial obsession—prefer to line their nests with soft moss, grass or animal fur.
These birds do horde food items, are known for stealing food (even from kitchen tables, if they have access), and may show an attraction toward certain non-edible items. They don’t collect shiny objects per se, but may (extremely rarely) take them and even hide them someplace as an outgrowth of these behaviors.
Anecdotes of these birds snatching up human valuables are plentiful, and many of them are undoubtedly true. Watches freshly removed in the outdoors are a favorite.
Birds are certainly capable of detecting shiny and colorful items. But in all these cases, the items are probably perceived as potential food, not as Crow Family knickknacks. And it is likely that the shape of the object is more important than its color and brightness.
Detailed reports from people who have raised crows and ravens in captivity provide some telling clues.
A classic 1927 report comes from Norman Criddle of Manitoba, Canada, who raised four young crows. He reported that they regularly collected a wide variety of objects together and then hid them. When they became older, they regularly hid food items for later eating—including shoving berries under a handkerchief in Criddle’s own front shirt pocket.
This tallies with modern observations that young birds aren’t sure of the food value of all the various items they see day to day, so they hide some to experiment with later.
It is quite likely that many of the “shiny object” theft reports are the work of young birds experimenting with possible food.
Bernd Heinrich, a University of Vermont biology professor, got even more detailed information in his work with young ravens. He was intrigued when he gave them an egg and they immediately attempted to eat it, even though they had never seen one before.
Presenting them with objects, both edible and inedible, of various shapes, he found they would faithfully attempt to eat any smooth, rounded object—including hickory nuts (which they found they didn’t like), a Ping-Pong ball, film canisters and a red-and-white fishing float.
He also found that bright color was not so important to them, as their response when presented with a variety of flowers was idiosyncratic. (There’s not an edibility problem here; ravens, like crows and magpies, are omnivorous.)
He also experimented by secretly burying a piece of roadkill they liked in different places under snow. He found they used sight—visual cues in the disturbances of the snow—rather than smell to find the roadkill again. This shows sight is critical to the birds’ food-finding.
Our small valuables—coins, rings, watches—tend to be smooth and rounded. It’s likely the birds simply consider them a meal, and dump them later when it’s clear they’re not.
Nov. 7, 2002
By John Ruch
© 2002
Q: Why do crows collect shiny objects?
—Gingerkitten Telekinesis
A: If you root around in a crow’s nest expecting to find an avian Aladdin’s Cave of gold watches, coins, rings or even bottle caps, you will be sorely disappointed.
Crows, ravens and magpies—all similarly accused of this superficial obsession—prefer to line their nests with soft moss, grass or animal fur.
These birds do horde food items, are known for stealing food (even from kitchen tables, if they have access), and may show an attraction toward certain non-edible items. They don’t collect shiny objects per se, but may (extremely rarely) take them and even hide them someplace as an outgrowth of these behaviors.
Anecdotes of these birds snatching up human valuables are plentiful, and many of them are undoubtedly true. Watches freshly removed in the outdoors are a favorite.
Birds are certainly capable of detecting shiny and colorful items. But in all these cases, the items are probably perceived as potential food, not as Crow Family knickknacks. And it is likely that the shape of the object is more important than its color and brightness.
Detailed reports from people who have raised crows and ravens in captivity provide some telling clues.
A classic 1927 report comes from Norman Criddle of Manitoba, Canada, who raised four young crows. He reported that they regularly collected a wide variety of objects together and then hid them. When they became older, they regularly hid food items for later eating—including shoving berries under a handkerchief in Criddle’s own front shirt pocket.
This tallies with modern observations that young birds aren’t sure of the food value of all the various items they see day to day, so they hide some to experiment with later.
It is quite likely that many of the “shiny object” theft reports are the work of young birds experimenting with possible food.
Bernd Heinrich, a University of Vermont biology professor, got even more detailed information in his work with young ravens. He was intrigued when he gave them an egg and they immediately attempted to eat it, even though they had never seen one before.
Presenting them with objects, both edible and inedible, of various shapes, he found they would faithfully attempt to eat any smooth, rounded object—including hickory nuts (which they found they didn’t like), a Ping-Pong ball, film canisters and a red-and-white fishing float.
He also found that bright color was not so important to them, as their response when presented with a variety of flowers was idiosyncratic. (There’s not an edibility problem here; ravens, like crows and magpies, are omnivorous.)
He also experimented by secretly burying a piece of roadkill they liked in different places under snow. He found they used sight—visual cues in the disturbances of the snow—rather than smell to find the roadkill again. This shows sight is critical to the birds’ food-finding.
Our small valuables—coins, rings, watches—tend to be smooth and rounded. It’s likely the birds simply consider them a meal, and dump them later when it’s clear they’re not.
Geese Flying in V
Stupid Question ™
June 6, 2002
By John Ruch
© 2002
Q: Why do geese fly in a V formation? How do they decide who’s the leader?
—Duane Ott
A: Nobody knows, though science’s armchair speculations on the subject are often presented as fact.
Almost all large migratory birds—geese, cranes, swans, pelicans—fly in some sort of V formation. Double and multiple Vs are known, as are U formations and diagonal lines. The “leader” appears to be a matter of position only; the birds regularly switch positions in the formation throughout their flight.
The V can be ragged and is sometimes discarded. Cranes are known to move into tighter groups when they hit “thermals”—updrafts of air they can glide on without flapping.
The most popular theory was put forth in a 1970 article in the journal “Science” and has been lazily quoted as absolute fact ever since. It says that upward airflow from the birds’ beating wingtips (a known aerodynamic effect) gives extra lift to their neighbors’ wings in the V formation, thus reducing the amount of work they all need to do. Math wankery has “estimated” energy savings of 20 percent and a 70 percent increase in flying range.
First of the theory’s many problems is that it would actually work best if the birds flew wingtip-to-wingtip in a straight line, which they never do. The standard excuse is that the birds on the ends of the line would get half the benefit, and that the V at least gives everybody some help. But it’s a fact that birds always change position in formation anyway, so being on the end for a while couldn’t hurt.
It’s also been noted that the truly sweet spot would be within the angle of the V, where birds could enjoy their neighbors’ updrafts without contributing their own. But birds never do this. The authors could only presume some sort of avian police that keep the birds in line, which frankly seems silly.
The study also reported that single birds flying in apparent solo migration actually fly 24 percent faster than birds in the V. They rationalized the birds were stragglers hurrying to catch up—but how could they, if the V has a significantly greater efficiency and range?
Similarly, Canada geese often have “scout” birds out front, apparently looking for danger and/or landing spots. What about their efficiency?
As for the lead bird, some say it gets no advantage and has to drop back when it’s tired. Others say it benefits from its neighbors like everybody else.
A simpler theory says that like bike racers, the birds in front produce a slipstream effect, reducing air resistance for those behind them and lessening their work.
But another theory says the birds in front create air turbulence, not a slipstream, and that the V formation keeps everybody out of it.
Konrad Lorenz, a famed expert on goose behavior, dismissed aerodynamics and said it’s really all about visibility. He noted that geese also stay slightly to each other’s side when walking, swimming and taking flight, all presumably to maintain a clear view ahead. He said it’s particularly noticeable when they’re swimming across a large body of water.
June 6, 2002
By John Ruch
© 2002
Q: Why do geese fly in a V formation? How do they decide who’s the leader?
—Duane Ott
A: Nobody knows, though science’s armchair speculations on the subject are often presented as fact.
Almost all large migratory birds—geese, cranes, swans, pelicans—fly in some sort of V formation. Double and multiple Vs are known, as are U formations and diagonal lines. The “leader” appears to be a matter of position only; the birds regularly switch positions in the formation throughout their flight.
The V can be ragged and is sometimes discarded. Cranes are known to move into tighter groups when they hit “thermals”—updrafts of air they can glide on without flapping.
The most popular theory was put forth in a 1970 article in the journal “Science” and has been lazily quoted as absolute fact ever since. It says that upward airflow from the birds’ beating wingtips (a known aerodynamic effect) gives extra lift to their neighbors’ wings in the V formation, thus reducing the amount of work they all need to do. Math wankery has “estimated” energy savings of 20 percent and a 70 percent increase in flying range.
First of the theory’s many problems is that it would actually work best if the birds flew wingtip-to-wingtip in a straight line, which they never do. The standard excuse is that the birds on the ends of the line would get half the benefit, and that the V at least gives everybody some help. But it’s a fact that birds always change position in formation anyway, so being on the end for a while couldn’t hurt.
It’s also been noted that the truly sweet spot would be within the angle of the V, where birds could enjoy their neighbors’ updrafts without contributing their own. But birds never do this. The authors could only presume some sort of avian police that keep the birds in line, which frankly seems silly.
The study also reported that single birds flying in apparent solo migration actually fly 24 percent faster than birds in the V. They rationalized the birds were stragglers hurrying to catch up—but how could they, if the V has a significantly greater efficiency and range?
Similarly, Canada geese often have “scout” birds out front, apparently looking for danger and/or landing spots. What about their efficiency?
As for the lead bird, some say it gets no advantage and has to drop back when it’s tired. Others say it benefits from its neighbors like everybody else.
A simpler theory says that like bike racers, the birds in front produce a slipstream effect, reducing air resistance for those behind them and lessening their work.
But another theory says the birds in front create air turbulence, not a slipstream, and that the V formation keeps everybody out of it.
Konrad Lorenz, a famed expert on goose behavior, dismissed aerodynamics and said it’s really all about visibility. He noted that geese also stay slightly to each other’s side when walking, swimming and taking flight, all presumably to maintain a clear view ahead. He said it’s particularly noticeable when they’re swimming across a large body of water.
Carrier Pigeons
Stupid Question ™
Feb. 21, 2002
By John Ruch
© 2002
Q: How do carrier pigeons work? Are they still used today?
—Ben Hauck
A: First things first: we’re really talking about homing pigeons—pigeons bred to be especially good at finding their way home. Carrier pigeons are homing pigeons carrying messages. Racing pigeons are homing pigeons bred and trained to fly home as fast as possible.
All pigeons have some degree of homing ability. Humans have been breeding homing pigeons for millennia.
Until radio, the carrier pigeons was the fastest means of long-distance communication. It was also simple: get the pigeon comfortable in its loft. You an ten take it great distances away and release it, and it will return home. Vast pigeon networks were built this way.
The famous Reuters news service began in 1851 as a carrier-pigeon network. The US military used carrier pigeons up through the Korean War; Iraq used them in the Gulf War.
Today, carrier pigeons are used regularly only in remote areas of countries such as India. In the industrialized world, their use is whimsical or idiosyncratic: a 1998 attempt to smuggle diamonds from a South African mine by pigeon, or an Internet connection achieved last May by carrier pigeons.
The primary use for homing pigeons today is racing. The strong, fast racing breeds were started in Belgium around 1810. Racing pigeons today can fly 60 mph and find their way home from up to 1,000 miles away (though some do get lost).
The homing ability is a mystery, especially since it’s employed so quickly and with no apparent effort.
In experiments in which pigeons were fitted with frosted goggles that admitted only diffuse light and released 100 miles from home, most were able to navigate to within a quarter-mile of their loft. This suggests that regular vision is important in finding the exact loft, but that something else is involved in the long-distance journey.
That something is probably several abilities used in concert. They almost certainly use the Sun for general orientation, and possibly can somehow calculate their position based on its position.
Pigeons can hear extremely low-frequency sounds (down to 0.05 hertz) and can see ultraviolet light. Evidence suggests they are also sensitive to Doppler and polarization shifts in such sound and light, meaning they could use them to orient themselves.
Most remarkably, pigeons almost certainly have an internal magnetic compass. Experiments show that they have trouble navigating if an electromagnet is placed on their heads. There is also correlation between sunspot activity, which can cause magnetic storms on Earth, and mass mis-navigation. (Most pigeon-racers monitor sunspot activity.)
Furthmore, the compass has apparently been found. It’s a tiny bit of tissue in the head that contains about 10 million oblong crystals of magnetite—a magnetic iron oxide that makes a perfect compass needle. The shape and tiny size of these crystals probably makes them an extremely sensitive compass, which the pigeon “reads” by sensing pressure changes as the tissue expands in various directions based on orientation to the Earth’s magnetic field.
Feb. 21, 2002
By John Ruch
© 2002
Q: How do carrier pigeons work? Are they still used today?
—Ben Hauck
A: First things first: we’re really talking about homing pigeons—pigeons bred to be especially good at finding their way home. Carrier pigeons are homing pigeons carrying messages. Racing pigeons are homing pigeons bred and trained to fly home as fast as possible.
All pigeons have some degree of homing ability. Humans have been breeding homing pigeons for millennia.
Until radio, the carrier pigeons was the fastest means of long-distance communication. It was also simple: get the pigeon comfortable in its loft. You an ten take it great distances away and release it, and it will return home. Vast pigeon networks were built this way.
The famous Reuters news service began in 1851 as a carrier-pigeon network. The US military used carrier pigeons up through the Korean War; Iraq used them in the Gulf War.
Today, carrier pigeons are used regularly only in remote areas of countries such as India. In the industrialized world, their use is whimsical or idiosyncratic: a 1998 attempt to smuggle diamonds from a South African mine by pigeon, or an Internet connection achieved last May by carrier pigeons.
The primary use for homing pigeons today is racing. The strong, fast racing breeds were started in Belgium around 1810. Racing pigeons today can fly 60 mph and find their way home from up to 1,000 miles away (though some do get lost).
The homing ability is a mystery, especially since it’s employed so quickly and with no apparent effort.
In experiments in which pigeons were fitted with frosted goggles that admitted only diffuse light and released 100 miles from home, most were able to navigate to within a quarter-mile of their loft. This suggests that regular vision is important in finding the exact loft, but that something else is involved in the long-distance journey.
That something is probably several abilities used in concert. They almost certainly use the Sun for general orientation, and possibly can somehow calculate their position based on its position.
Pigeons can hear extremely low-frequency sounds (down to 0.05 hertz) and can see ultraviolet light. Evidence suggests they are also sensitive to Doppler and polarization shifts in such sound and light, meaning they could use them to orient themselves.
Most remarkably, pigeons almost certainly have an internal magnetic compass. Experiments show that they have trouble navigating if an electromagnet is placed on their heads. There is also correlation between sunspot activity, which can cause magnetic storms on Earth, and mass mis-navigation. (Most pigeon-racers monitor sunspot activity.)
Furthmore, the compass has apparently been found. It’s a tiny bit of tissue in the head that contains about 10 million oblong crystals of magnetite—a magnetic iron oxide that makes a perfect compass needle. The shape and tiny size of these crystals probably makes them an extremely sensitive compass, which the pigeon “reads” by sensing pressure changes as the tissue expands in various directions based on orientation to the Earth’s magnetic field.
March 27, 2008
Sea-Monkeys
Stupid Question ™
Dec. 14, 2000
By John Ruch
© 2000
Q: What ever happened to Sea-Monkeys, and just what the heck were they anyway?
—Suzan Thoma
A: A staple of comic book ads, Sea-Monkeys promised to give children total dominion over a kingdom of tiny sea creatures, usually depicted as human/fish hybrids with three stalks rising crown-like from their heads. By mixing three packets of gunk (“Water Purifier,” “Sea-Monkey Eggs” and “Growth Food”) with water, kids were instead treated to near-microscopic dots that may or may not have been alive.
Sea-Monkeys were the brainchild of Harold von Braunhut, who also invented X-Ray Specs. Exactly 40 years after their introduction, Sea-Monkeys are still being sold through von Braunhut’s Maryland-based Transcience Corporation.
The Sea-Monkey market hit a slump in the mid-’90s, when distributor ExploraToy started marketing them as an “educational” toy.
Back when I was a kid, rumors ran rampant about what Sea-Monkeys were, from bits of inert matter to a “flea circus”-style illusion. But with this new “educational” angle, von Braunhut et al. readily reveal that Sea-Monkeys are in fact brine shrimp.
First discovered in the salt ponds of Lymington, England in 1755, brine shrimp are tiny crustaceans (rarely more than half an inch long) that live in highly saline water.
Despite the “shrimp” moniker, they’re not closely related to shrimp; despite the “Sea-Monkey” moniker, they don’t live in the open sea. They thrive in salt lakes and bays. (More than 30 companies harvest them from Utah’s Great Salt Lake alone.) They have compound eyes on projecting stalks, tapered bodies and 11 pairs of legs; under a lens, they look something like silverfish.
Brine shrimp are survivors. In good conditions, they give birth to live young. But in bad conditions, they lay eggs encased in a tough coating called a cyst. These cysts can withstand extreme temperatures, and will survive complete drying out for dozens of years. But add a little warm salt water, and the young (“Baby Sea-Monkeys”) quickly hatch in perfect condition.
Sea-Monkeys are a special long-lived breed of brine shrimp, and what active lives they are. They may face the Aqua-Leash (a suction device for picking up Sea-Monkeys), Cupid’s-Arrow Mating Powder or the Sea-Monkey Speedway.
The speedway is a race course exploiting the fact that if you create a current in water, brine shrimp instinctively swim against it. Ohio State University hosted a Sea-Monkey race in 1999.
There are also watches and necklaces containing Sea-Monkeys, as well as a space shuttle-shaped aquarium to commemorate Sea-Monkeys going into space on the same mission as John Glenn. (Brine shrimp already went up the US Apollo and the Soviet Cosmos programs.)
Von Braunhut originally sold Sea-Monkeys under the creepy name “Instant Life,” and has faced complaints that it’s unethical to sell animals as toys. However, it might be better than the most common commercial use of brine shrimp: live fish food.
Dec. 14, 2000
By John Ruch
© 2000
Q: What ever happened to Sea-Monkeys, and just what the heck were they anyway?
—Suzan Thoma
A: A staple of comic book ads, Sea-Monkeys promised to give children total dominion over a kingdom of tiny sea creatures, usually depicted as human/fish hybrids with three stalks rising crown-like from their heads. By mixing three packets of gunk (“Water Purifier,” “Sea-Monkey Eggs” and “Growth Food”) with water, kids were instead treated to near-microscopic dots that may or may not have been alive.
Sea-Monkeys were the brainchild of Harold von Braunhut, who also invented X-Ray Specs. Exactly 40 years after their introduction, Sea-Monkeys are still being sold through von Braunhut’s Maryland-based Transcience Corporation.
The Sea-Monkey market hit a slump in the mid-’90s, when distributor ExploraToy started marketing them as an “educational” toy.
Back when I was a kid, rumors ran rampant about what Sea-Monkeys were, from bits of inert matter to a “flea circus”-style illusion. But with this new “educational” angle, von Braunhut et al. readily reveal that Sea-Monkeys are in fact brine shrimp.
First discovered in the salt ponds of Lymington, England in 1755, brine shrimp are tiny crustaceans (rarely more than half an inch long) that live in highly saline water.
Despite the “shrimp” moniker, they’re not closely related to shrimp; despite the “Sea-Monkey” moniker, they don’t live in the open sea. They thrive in salt lakes and bays. (More than 30 companies harvest them from Utah’s Great Salt Lake alone.) They have compound eyes on projecting stalks, tapered bodies and 11 pairs of legs; under a lens, they look something like silverfish.
Brine shrimp are survivors. In good conditions, they give birth to live young. But in bad conditions, they lay eggs encased in a tough coating called a cyst. These cysts can withstand extreme temperatures, and will survive complete drying out for dozens of years. But add a little warm salt water, and the young (“Baby Sea-Monkeys”) quickly hatch in perfect condition.
Sea-Monkeys are a special long-lived breed of brine shrimp, and what active lives they are. They may face the Aqua-Leash (a suction device for picking up Sea-Monkeys), Cupid’s-Arrow Mating Powder or the Sea-Monkey Speedway.
The speedway is a race course exploiting the fact that if you create a current in water, brine shrimp instinctively swim against it. Ohio State University hosted a Sea-Monkey race in 1999.
There are also watches and necklaces containing Sea-Monkeys, as well as a space shuttle-shaped aquarium to commemorate Sea-Monkeys going into space on the same mission as John Glenn. (Brine shrimp already went up the US Apollo and the Soviet Cosmos programs.)
Von Braunhut originally sold Sea-Monkeys under the creepy name “Instant Life,” and has faced complaints that it’s unethical to sell animals as toys. However, it might be better than the most common commercial use of brine shrimp: live fish food.
Sea Gulls Not On Sea
Stupid Question ™
Jan. 20, 2000
By John Ruch
© 2000
Q: Where do the flocks of sea gulls on the Olentangy River in Columbus, Ohio come from? We’re hundreds of miles from the sea!
—J.M.
A: Today’s lesson: The human name for an animal doesn’t affect its actual origin and behavior.
“Sea gull” is a generic popular name, not a scientific one. There are actually many types of gulls. Many of them are indeed ocean shorebirds. But many also live on freshwater lakes and rivers far inland.
In fact, the “sea gull” is the state bird of Utah—and the subject of a Salt Lake City monument—because insect-munching California gulls saved the Mormons from an 1848 grasshopper plague.
Large numbers of gulls breed in the big lakes of Canada and the northern U.S.—including Lake Erie, which is probably where most of ours come from. They frequently travel down America’s great waterways, such as the Ohio and the Mississippi.
Two types of gull frequent Columbus’ rivers, reservoirs, farm fields and shopping mall parking lots. The most common is the ring-billed gull, which is crow-sized, with yellowish legs and black spots on its upper and lower bill that look like a vertical ring. They can be greedy eaters; several have been found choked to death after trying to swallow dead squirrels too big for their throats.
Around 1900, ring-bills didn’t even breed on Lake Erie, but their population has skyrocketed with the increase in human garbage dumps and fast-food litter on which the gulls scavenge. (Metro Parks naturalist Andrea Haslage calls the ring-bill “a suburban bird.”) Today, they’re actually more common inland than on seacoasts.
In the winter, they can be found as far south as Mexico and as far inland as Kansas and Colorado.
Less common is the larger, pink-legged herring gull (which, 100 years ago, was more common than the ring-billed gull). Herring gulls are able to drink either fresh or salt water, and are known for breaking clams open by dropping them onto rocks from the air.
No gulls breed around here, so all the ones we see are visitors. Exactly why they’re visiting, however, is hard to say. Most gulls do make seasonal moves north and south, but they’re not hardcore migrators. They’ll happily hang around any place that has some open water and plenty of food (so mild, ice-free winters keep them around longer).
A bird’s age may affect how long it hangs around (though experts can’t agree on whether younger or older birds are more likely to do so).
Gulls definitely head north in the spring, since they always return to the same breeding grounds. Gulls too young to breed spend more time wandering around.
And in general, gulls are known for flying considerable distances scouting for food. Some of our gulls may simply be making a day trip from Lake Erie.
Whatever the individual reasons, gulls are most common in Columbus during the spring and fall quasi-migrations, but can be found all year ’round. (I saw 30 of them Sunday at Antrim Park.)
As Metro Park’ Haslage says, “If there’s open water, they’ll be here.”
Jan. 20, 2000
By John Ruch
© 2000
Q: Where do the flocks of sea gulls on the Olentangy River in Columbus, Ohio come from? We’re hundreds of miles from the sea!
—J.M.
A: Today’s lesson: The human name for an animal doesn’t affect its actual origin and behavior.
“Sea gull” is a generic popular name, not a scientific one. There are actually many types of gulls. Many of them are indeed ocean shorebirds. But many also live on freshwater lakes and rivers far inland.
In fact, the “sea gull” is the state bird of Utah—and the subject of a Salt Lake City monument—because insect-munching California gulls saved the Mormons from an 1848 grasshopper plague.
Large numbers of gulls breed in the big lakes of Canada and the northern U.S.—including Lake Erie, which is probably where most of ours come from. They frequently travel down America’s great waterways, such as the Ohio and the Mississippi.
Two types of gull frequent Columbus’ rivers, reservoirs, farm fields and shopping mall parking lots. The most common is the ring-billed gull, which is crow-sized, with yellowish legs and black spots on its upper and lower bill that look like a vertical ring. They can be greedy eaters; several have been found choked to death after trying to swallow dead squirrels too big for their throats.
Around 1900, ring-bills didn’t even breed on Lake Erie, but their population has skyrocketed with the increase in human garbage dumps and fast-food litter on which the gulls scavenge. (Metro Parks naturalist Andrea Haslage calls the ring-bill “a suburban bird.”) Today, they’re actually more common inland than on seacoasts.
In the winter, they can be found as far south as Mexico and as far inland as Kansas and Colorado.
Less common is the larger, pink-legged herring gull (which, 100 years ago, was more common than the ring-billed gull). Herring gulls are able to drink either fresh or salt water, and are known for breaking clams open by dropping them onto rocks from the air.
No gulls breed around here, so all the ones we see are visitors. Exactly why they’re visiting, however, is hard to say. Most gulls do make seasonal moves north and south, but they’re not hardcore migrators. They’ll happily hang around any place that has some open water and plenty of food (so mild, ice-free winters keep them around longer).
A bird’s age may affect how long it hangs around (though experts can’t agree on whether younger or older birds are more likely to do so).
Gulls definitely head north in the spring, since they always return to the same breeding grounds. Gulls too young to breed spend more time wandering around.
And in general, gulls are known for flying considerable distances scouting for food. Some of our gulls may simply be making a day trip from Lake Erie.
Whatever the individual reasons, gulls are most common in Columbus during the spring and fall quasi-migrations, but can be found all year ’round. (I saw 30 of them Sunday at Antrim Park.)
As Metro Park’ Haslage says, “If there’s open water, they’ll be here.”