Thursday, March 3, 2011

Whale attacks on ships--the historical record

_____________________________________________________
Moby Dick attacks pursuing whaleboats.  Source
Melville based the ending of Moby Dick on the story of the Essex.

Recently, there have been stories in the news about whales causing damage to yachts, even sinking them.  But it's difficult to determine whether these are accidental collisions, or attacks by the whales. 

Even if real attacks, the whales may have felt menaced by ships bearing down on them, or they mistook the ships for rivals.

But during the heyday of the whaling industry in the 1800s, there were two accounts of full-sized sailing ships attacked and sunk by whales.

Attack on the Essex

In 1830, the whaleship Essex was hunting in new whaling grounds along the equator, two thousand miles west of the coast of South America.  They lowered their three small whaleboats to pursue some sperm whales, but when one of the boats was damaged by the tail of a whale they had harpooned, the First Mate named Chase returned to the whaleship for repairs. 

Next, the whaleship was attacked twice by a bull sperm whale, about 85 feet long.  Here's a description of the the second ramming, from a wonderful book* by Nathaniel Philbrick:

Chase turned and saw a vision of "fury and vengeance" that would haunt him in the long days ahead.

     With its huge scarred head halfway out of the water and its tail beating the ocean into a white-water wake more than forty feet across, the whale approached the ship at twice its original speed--at least six knots.  Chase, hoping "to cross the line of his approach before he could get up to us, and thus avoid what I knew, if he should strike us again, would prove our inevitable destruction," cried out to Nickerson, "Hard up!"  But it was too late for a change of course.  With a tremendous cracking and splintering of oak, the whale struck the ship just beneath the anchor....  This time the men were prepared for the hit.  Still, the force of the collision caused the whalemen's heads to jounce on their muscled necks as the ship lurched to a halt on the slablike forehead of the whale.  The creature's tail continued to work up and down, pushing the 238-ton ship backward until... water surged up over the transom.

     One of the men who had been belowdecks ran up onto the deck shouting, "The ship is filling with water." (p.83)

 Within ten minutes of the crash, the ship was awash and capsized.  Over the next day, the men salvaged what they could from the wreck, made sails for their three 25-foot whaleboats, and then prepared to sail 4,500 miles back to the coast of South America.  During that three-month ordeal, they ran out of food, and began to eat one another.  Only eight of the 20 crew members survived.

This wasn't the only sinking due to a whale.  In 1807, the whaleship Union accidentally collided with a sperm whale at night and sank.  Thirty years later, the whaleship Ann Alexander, also cruising in the Pacific, became the second vessel to be "stove by a whale."  Source


Etching by William Bradford

While scores of smaller whaleboats pursuing whales had been smashed to bits over the years, in 1820 Nantucketers had never heard of a deliberate ramming of the mothership.

Why did the whale attack?

The attack on the Essex was so well-observed, and so apparently deliberate that--ever since--people have wondered about it.  Chase said: "He came directly from the shoal [group of whales] which we had just before entered, and in which we had struck three of his companions, as if fired with revenge for their sufferings."

In his modern retelling, Philbrick suggests that the whale may have mistaken the Essex for a rival bull.  A whale's vision in the water is limited, so they depend on "echolocation," a kind of sonar.  The Essex was only slightly longer than the attacking bull, though it was three times the whale's weight.  Before the attack, the First Mate was using a hammer to repair the damaged whaleboat.  The hammer may have made sounds, conducted through the hull and into the water, which resemble the clicking sounds that bulls make when they challenge one another.

Today, much has changed, making a deliberate attack much less probable.
  • Most commercial whaling has ended.
  • Whales are less numerous, and the remaining bulls are smaller.
  • Whales are more familiar with humans and their ships.
  • Ships are larger--and many make a lot of  noise.

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*  I heartily recommend In the Heart of the Sea by N. Philbrick.  It's exciting, well-written, and puts everything in historical context.  But it's only the latest of several accounts on the sinking of the Essex.

Tuesday, September 28, 2010

Coyote attacks

Coyotes used to be a symbol of the American West--the stuff of folklore and cowboy song. Throughout the 1900s, they were spreading to the East. Now they are common throughout the country, often living right under the nose of urban residents. For example, wildlife experts estimate there are over 2,000 living in Chicago, even downtown, where one walked into a Quiznos store.

I live in Madison, Wisconsin. If you walk on our lakes in winter, after fresh snow has fallen, you will see a myriad of coyote tracks, along with those of other mammals like fox, beaver, mink, deer, raccoon, rabbit, and squirrel.

Coyote tracks look like those of a medium-sized dog, except that they typically trend straight as an arrow. In contrast, dog tracks are nearly always found looping out and back to human tracks, or zig-zagging.

Fox tracks also head in a beeline, but are a good deal smaller than coyote tracks.

Although there are doubtless many coyotes living in your area, it's rare to hear them howl. That's because they are extremely wary of humans.

Coyote attacks

In March of this year, coyotes attacked dogs several times in Cape Cod. These attacks may have involved rabid coyotes, since coyotes usually avoid dogs as large as the ones attacked.

But there are other reasons why coyotes attack dogs: It may be for food (in the case of small dogs), or because coyotes see dogs as a threat to their territory or to their young.

Healthy coyotes are extremely wary of humans--but attacks on humans have occurred in Cape Cod, and recently in a suburb of New York. There was a fatal attack last year on a woman in Canada.

Don't worry--attacks on humans are extremely rare. The few that do occur are the inevitable result of large numbers of people and coyotes living close to one another. Your chances of you or your pet being injured by a dog are far greater.

The Coywolf

Now that I've put your mind at rest--here's some unexpected news. The coyotes in Massachusetts are actually wolf-coyote hybrids. That explains why coyotes there are larger than the coyotes out West, where they originated. The adults on Cape Cod weigh 30-40 pounds.

Jonathan Way and three other wildlife biologists studied coyotes caught in traps on Cape Cod and near Boston. Their conclusions about wolf-coyote hybrids are based on studies of DNA from the animals. They think that as the coyotes spread eastward through Canada, they interbred with the Eastern Wolves found there.

Other conclusions from the study

  • Although coyotes do interbreed with dogs in the western US, they don't in the Northeastern states.
  • "Coyote social groups...are made up of family groups.... Offspring typically remain with their parents anywhere from 6 months to about 2 years of age before dispersing to new areas.... "
  • "Typically 3–5 adults live together in a territorial pack...." The advantages of living in packs are better success in hunting large prey (like deer), better defense of the territory, improved survivability of pups, and preventing theft of prey already killed. The packs typically consist of a breeding pair, plus a few related animals.
  • These "coywolves" seem to prefer prey more typical of coyotes than wolves. Wolves prey almost entirely on deer, whereas the hybrids eat anything from deer to rabbits to small rodents, not to mention pets, pet food left outside, and garbage.
  • They travel long distances (10-15 miles a day).
Precautions
  • If you live near woods, don't leave small children or small pets outdoors alone.
  • Don't leave pet food outdoors; keep garbage cans covered.
  • Cats are especially vulnerable--some coyotes appear to specialize in eating cats. 
More links

New York Times review article on coyotes
More advice about living with coyotes
Coyotes--Never out of sight, or mind (excellent essay)
Eastern coyote/coywolf web page by Jonathan Way
The coyote wars on Cape Cod
Animal attack files
Purchase Suburban Howls--a book by Jonathan Way
New book on Coyotes with good reviews
Coyote Attack.  Book for children

Wednesday, July 21, 2010

Penguin jumps into boat to escape killer whales

I stumbled onto this great video of a gentoo penguin in Antarctica, escaping killer whales.  It shows some tourists in an inflatable boat, watching killer whales chasing penguins.  Suddenly, to the surprise of the tourists, a penguin lands in their boat.

Predators of penguins

In the Antarctic, killer whales and leopard seals regularly eat penguins.  The predators usually patrol along the coast just outside the penguin colony, where large numbers of the aquatic birds come and go.  I haven't watched killer whales preying on penguins, but I have seen many attacks by leopard seals on Adelie penguins--close relatives of the gentoos.

The leopard seal skins the penguin after catching one, tossing it violently too and fro while hanging onto a flap of skin, until the skin comes off.

For the much larger killer whales, skinning penguins is probably too delicate a task.  For them, a penguin would be little more than a peanut is for us.

Outmaneuvering predators

Penguins can probably turn much more tightly than a a seal or killer whale, so that is their only hope of escape--that, or jumping up onto the ice (or onto a boat). 

When trying to catch penguins on land with a snowmobile (for scientific research), the penguins easily out turn the vehicle.  You have to jump off the snowmobile with a net, and dash after them for the final capture.

By swimming fast under water, then turning upward, penguins can jump about two meters above the water at the edge of an ice floe, plopping down onto their feet on the ice.  They need to do this because the chunks of floating ice have vertical edges, often several feet high.  Floating sea ice can be about ten feet thick.  If 1/10 of that floats above the surface, then the penguins have to be able to jump at least one foot high to get onto a typical block of ice.

So, having a penguin escape onto a small boat would be a perfectly normal kind of behavior.  Once landing, and seeing the people, the penguin normally wouldn't be afraid, because they have no land predators (other than scavenging birds that take chicks).  So over the eons, they have lost their fear of any large animals on land, because it serves no purpose.

However, penguins do have a sense of personal distance.  They would normally be uncomfortable with a person being closer than about six feet--although the exact distance depends on the personality of the individual penguin.

What I found interesting about this video was that the penguin didn't seem to mind a number of people closer than six feet.  I suspect he sensed that he was safer where he was on the boat.  In the water, it would have been almost certain death.

Grabbing a breath of air

In the video, you can see a number of penguins briefly popping out of the water as they try to escape the killer whales.   This is called "porpoising."  It has several functions:
  • The penguins can see where they are and where the nearest safety lies.  While they can see well under water, they can see further through the air.
  • When briefly jumping above the water, the penguins grab a breath of air.  Unlike whales and porpoises, which have a blow hole in the top of the head, penguins breathe through their mouths, so they have to get clear of the water.
  • When coasting through the air, there is less resistance than when coasting through water.  So porpoising saves energy.
Penguins probably grab a breath of air every hundred feet or so.  So if you see a few penguins "porpoising," there are probably a lot more swimming underwater in the same area.

#     #     #

Other cases of animals landing on boats here: Right whale lands on sailboat, South Africa. 

Wednesday, June 2, 2010

What to do if you are attacked by a bird

As a Ph.D. student in Ornithology, I was attacked by many species of birds.

Ninety-nine percent of all attacks by wild birds happen when birds are defending their nests.  You are too close to their nest.  Back away, and the attacks will cease.   Sometimes these defensive attacks will start when you are still a good distance from the nest.  They are more motivated to attack if they have eggs or chicks.  If they are just building the nest, they are less likely to attack, and may just abandon the nest--considering the location too risky.

And the other 1% of attacks?  Many species of birds--Eastern Kingbirds, Red-wing Blackbirds, Crows, Ravens--attack hawks and owls, even when the predator isn't near their nests.  This is called "mobbing."   Smaller birds mob crows.  There's a wonderful video on You Tube of an Eastern Kingbird riding on the back of a flying hawk, while pecking it.

Crows can be trained to "mob" people.  In one interesting experiment at a University, researchers donned a "Dick Cheney mask, while handling trapped crows.  The crows learned to recognize the Cheney face, and later when releassed, mobbed other people wearing the Cheney mask.  I don't have direct experience with being "mobbed," so I can't say how common it is.  Probably quite uncommon.

Wild birds do not get rabies, so you don't have to worry about attack by a rabid bird.

A bad rap for the birds

It's possible that someone might have tamed a bird, such as a parrot.  It might approach you, attempting to land on your shoulder.  You might misinterpret this as an attack. 

Once I had a pet Ring-billed gull that I reared from an egg.    I used to take it out for practice flights. My telephone number was on a band on its leg. When it reached adolescence at the end of the summer, on one of these flights it said "good-bye" and flew off.   About a week later I received a call from the campus policeman.  "I have a sick bird here with your phone number on it.  Is it yours?  Do you want to pick it up?"   The bird wasn't sick--it was just begging from people on the street, and this was such strange behavior they thought it was sick.

Here's another example of a tame bird getting a bad rap.  One of my fellow grad students, Jerry McGahan, was studying the Andean Condor.  He had found a chick on a nest in the Andes, and brought it back for study.  Now nearly full-grown, he would take it out for an exercise flight on campus around suppertime, when few people were about.

One lazy summer day, a coed had fallen asleep on the campus lawn, and was still there snoozing when Jerry brought his huge black bird, with it's six-foot wingspread, out for a flight.  The magnificent bird rose and circled around, then descended to land next to the coed.    Perhaps she heard its wings or sensed a shadow, for just as it landed, she awoke in stark terror.

I've heard that ostriches have a nasty kick.

Many kinds of birds, such as gulls and corvids (crows, ravens, and jays) will try to snatch food from your hand or picnic table.  In San Francisco Bay, they follow the ferries and cruise ships.  If , while crossing the Bay, you hold something in your hand to eat, gulls will swoop down and try to snatch it.  Again, this isn't an attack, but many people misinterpret the bird's intentions.  I've even had one of the jays of the Western US land on my head while I was popping something tasty into my mouth.    At the University of Wisconsin in Madison, house sparrows hop around the tables, looking for scraps.

If freeloading birds bother you, put away the food, or go indoors.  At the very least, don't hold it in a way they stand a chance of grabbing it.  Like the gulls afraid of the teddy bear eyes, all birds are very visual, very clever, and very fast.  They are watching and judging your every move.

There is one bird species, recently discovered, with poisonous plumage.

Some birds like sandpipers fly fast in tight formations.  If you are walking on the beach, one of these flocks might pass nearby and frighten you.  But it's purely an accident--they meant no harm.

Some feisty birds I've known

If you walk by their nests, Adelie penguins will charge out and attack.  Males are more aggressive than females.  They will fix their bill to your pants, and beat you on the shin with their hard, bony flippers.  If you spend a lot of time among penguins, your legs will soon be covered with little blood blisters (from their bites) which we call the "penguin pox."  There's a lot of variation in aggressiveness, depending on the penguin's sex, age, personality, time of year, and so on.  Some just flee when you pass by; a few will attack even if you are 15 feet from their nest.

Most kinds of gulls and shorebirds will attack when you walk close to their nests on the ground.  Many are colonial; when you enter the colony, all rise into the air and circle, giving alarm calls.  It can be frightening and confusing with so much noise.   Some of the birds who have nests close to where you are standing will swoop down to peck your head, hit it with their feet, or defecate on you.  Once I was in a Forster's Tern colony checking on nests.  There were only 11 nests, but the feisty little birds actually drew blood from my scalp.

Ornithologist Don Miller, who often worked with Ring-billed Gulls, had a good defense for these swooping attacks.  He wore a pith helmet (like you see in old safari movies).  This effectively kept the bird droppings out of his hair (the helmet was splattered with white), and protected his head from blows.  But for an added measure of protection, he glued  two movable teddy bear eyes to the back of the helmet.  It turns out that if a swooping bird sees you are looking, it will be more cautious, and not actually hit you.   So the fake eyes make the birds keep their distance.  They still swoop, but they won't come close enough to hit you.

South Polar Skuas defecate, swoop and hit like their cousins the gulls, only skuas are a bit heavier and more fierce.  Their haranguing cries are pretty distinctive when they attack.

Ground-nesting Killdeers, on the other hand, will try to lead you away from their nest with the "broken wing" display.  No attack is involved, just a very convincing job of acting.

My scariest experience with birds

I was out walking alone late in the fall.  I noticed the leaves on the trail were quite disturbed, almost as if someone had been raking them.  After about a quarter mile, the trail ended at a cliff.  Just as I neared the cliff, the woods exploded with sound, and scared me to death.  A flock of about 20 wild turkeys took to the air, with their powerful wings slapping against the leaves and branches, making a dreadful racket.  It turns out the turkeys had been turning over the leaves, looking for food.  They moved silently ahead of me.  But when I came to the cliff, they could no longer escape on the ground, so they were forced to fly.

Red-wing black birds are common and pretty aggressive.  Since their nests are well-hidden in cattails (or sometimes in fields), you may have no idea you are close to a nest.  Swallows can be aggressive, and some nest in groups (colonies).

Geese and swans are very aggressive in defense of nests and young.  George Archbald told me of an unusual incident.  He had set up a breeding pair of swans (with wings clipped) on a small pond near his home in Baraboo, WI.   The pond was part of a small RV park.  One day, a man from the park was wading along the shore of the pond, and approached the nest, which was on the far shore from the RV park.   The swans fiercely attacked, clubbing him stoutly with their wings.  The man, forced into deeper water, struggled to regain the bank.  In the ensuing melee, he lost his wedding ring, and was quite angry about the swan attack.  But it was really his fault.

Cranes are also very fierce, and have very long, sharp bills.   I believe there is one freak case of a crane killing a man, by pecking him in the eye (and into the brain), where the skull is weak.  I'm sure the crane was either cornered, or defending its nest or young.

If you pull them out of their Antarctic burrows, Snow Petrels will explosively regurgitate a smelly, bright orange oil over you.  It can permanently stain your clothes.

Many birds have sharp toenails for defense, not to mention sharp beaks.  Once I visited writer Fran Hammerstrom at her home.  She had a Great Horned Owl for a pet, and that day, it was perched on her bare hand.  As I entered the living room, the owl became startled, and sudenly dug its long talons into her hand.  Fran said, very calmly, "Would you please come over here, and remove these talons from my hand?" She had to repeat several times as I struggled to understand what had happened, and what she wanted.   I grasped the talons of one foot with my fingers, and pried them from her bleeding hand, as the owl stood there rigid as a statue.

The bottom line

Fear of birds is greatly exaggerated.   Wild birds are quite harmless, for the most part, although some know how to look very threatening.  Hitchcock's movie The Birds gave them a bad name.   Insects, siders, poison arrow frogs, venomous snakes and lizards, snapping turtles, poisonous sea shells, and toothy mammals are more dangerous, on the whole, than birds.

If attacked, cover your head and move away until they stop.  If you are in a gull, swallow, or heron colony--your presence is very harmful to the birds.  The uproar will lead to the death of many chicks, especially if the weather is cold or wet.  It's essential that you leave the colony immediately.

Tuesday, June 1, 2010

Does predator urine repel problem animals?

In any discussion about rodents or other problem animals, you come across advertisements or testimonials about "predator urine."  They are at the top of any Google search about "mice in my car."

Now, research reported in Science magazine provides some support for urine:

"Even if a mouse has never seen a cat before, he'll turn tail when one is nearby.  Researchers suspected that the rodents somehow sniff out their would-be assassins, but exactly what they smelled was unclear.  Now scientists have isolated the compound, one of a class of urinary proteins that are secreted by cats, snakes, and a variety of other predators."

So, does this mean I should rush out an buy a bottle of fox urine? 

NO!   Reasons why urine is a poor solution:
  • There's no guarantee that what you are buying is effective, or even predator urine.
  • People who sell this stuff make a living by spreading disinformation.
  • Most pests are smart and adaptable--without a real predator around, they will lose their fear of the scent.
  • Do you really want to be putting urine or mothballs in your new car?
  • If it works for mice, that doesn't mean it works for squirrels.
  • The proven methods of pest control are far more effective: deny them food, entry, and shelter.
Think about it...  If you have a rodent problem, there's probably a population explosion going on.  There's something about your house or yard that's attracting them, and causing them to breed.  There's so many, they are starting to get really hungry, and looking for new places to hide and feed. 

They are desperate!  Under these extreme conditions, even if predator pee has a small repellent effect, they are not going to pay much attention!  You need to find out what is attracting them, and increasing their numbers--and then eliminate that.

The time you might take to locate and spread predator pee is better spent looking for the real cause of your pest problem.  Is there accessible cat food in the garage?

Remember--there's no free lunch... except for the mice in your garage.

Friday, May 21, 2010

Trapping and releasing problem animals--Does it work?

I've had comments posted to this blog about trapping and releasing problem animals as a humane solution.  I'm reprinting below the best explanation I've seen about why "trap and release" isn't a good idea.

"...It is also a misconception that you can move a wild animal to a new area, release it and it will instantly settle down and live happily ever after. Nature just isn't like that and releasing animals in a new area is a very tricky operation. It is unlikely that there will be a vacant territory and the animal will therefore wander widely in a strange area looking for somewhere to live. Since it does not know the area, it will not know the danger spots or best feeding sites. Invariably it will die fairly soon and it would have been far more humane to have killed the fox rather than dump it in a strange area.
Since dumping animals like this is clearly inhumane, such action could well be an offence under the Abandonment of Animals Act 1960.

Finally, many people do not want foxes released on their land. In this, their concerns are entirely justified; since displaced foxes do not know where to hunt, they are particularly likely to cause greater problems to farmers by killing fowl."  Source
 
Summary--why "trap and release" isn't a good idea
  • Not humane--animal will probably die anyway.
  • You are giving your problem to someone else. 
  • Only a few kinds of animals can be easily trapped--and you might be bitten.
  • Moving animals can upset natural populations, can spread disease, and may be illegal.
"Trap and release" is neither "humane," nor is it a "solution."

This bad idea is promoted by the makers of traps, for obvious reasons.

The only real solution is to avoid attracting animals--eliminate all food and shelter.  Make sure you aren't providing pet food in your back yard, or storing it uncovered in your garage.

Wednesday, May 12, 2010

Blurring the lines between humans and other species

Recently, scientists proposed that interbreeding between humans and Neanderthals occurred between 100,000 and 60,000 years ago in the Middle East.  The conclusion was based on the extraction and analysis of DNA from the bones of Neanderthals.  "Archaeologists have been debating for years whether the fossil record shows evidence of individuals with mixed features."  Source.

The scientists see "evidence for gene flow only from Neanderthals to modern humans."  So if you see someone with a heavy brow or receding chin who looks kind of primitive, he may indeed have some Neanderthal genes.

The recent discovery of a new species of human in a cave in Siberia suggests that three species of humans coexisted at the same time--modern humans, Neanderthals, and the new species.   The preliminary finding, reported in the NY Times, was based on DNA from a single finger bone.

So the question naturally arises--did either humans or Neanderthals interbreed with the third species?  The plot thickens!  The hobbit-like Flores Man may have been a fourth species on earth at the same time.

And all this raises the question--have humans ever interbred with chimpanzees, bonobos, orangutans, or gorillas?  Again, there is some evidence that the ancestors of modern humans and the ancestors of chimps interbred at some time in the distant past.  Today, the birth of a hybrid child would create enormous legal and ethical problems--so much so that the existence of such a child would probably be kept secret.  What possible motivations could lead to creation of such a child?

In fact, there's a rumor that famed zoologist George Schaller was called in to consult on such a case.

An organism with genes from more than one species is called a "chimera."  A human-mouse chimera was created when a human gene was inserted into a mouse.  Imagine the problems if intelligent mice escape from the lab!

Blurred boundaries in literature

The subject of humans breeding with or falling in love with apes sometimes surfaces in literature.  In the short story “Reflections of a Kept Ape,” Ian McEwan writes about "a woman who initiates a sexual relationship with a pet monkey—narrated from the point-of-view of the monkey."  Source

In "The Woman and the Ape" by Peter Hoeg, an intelligent ape escapes and makes off with an alcoholic woman, who eventually falls in love with the ape.

The sad story of Lucy

Lucy was a chimpanzee, raised from infancy by a human family--an experiment to see if a chimpanzee could learn human language, given the proper human upbringing.   Since Chimps can't form human vocal sounds, Lucy was taught American Sign Language.   She eventually learned well over 100 signs, and could engage in simple conversations. 

But as Lucy matured, she became extremely disruptive to her adoptive parents.  She developed great strength, along with unpredictable and unmanageable behavior.  Faced with losing any semblance of a normal life, her parents traveled the world, looking for some place where they could safely and humanely leave Lucy.  The problem was, Lucy thought she was human.

The chimp was eventually placed on an island in Gambia, along with other tame chimps being returned to the wild.  Unlike the others, Lucy alone thought she was human, and so she refused to learn how to forage as a wild chimp.  Janice Carter stayed with Lucy for a long time, living inside a cage on the island, trying to set an example of what Lucy needed to do.  Go here to learn about the haunting and tragic end to this story. 

Lucy was marooned in the strange dimension between humanity and animals.

*     *     *
More on Neanderthals here.