Wednesday, August 31, 2016

Rabbits Multiplying Like Rabbits

A plague of rabbits is upon us - brazen bunnies lollygagging about on our lawns and in are garden - barely deigning to hop, hop, hop away when one walks too close. A few theories can be put forward as to what cause or convergence of causes has led to this point, but whatever the reasons, we've got rabbits multiplying like rabbits.

Eastern cottontail, well camouflaged against summer-browned grass.
The rabbits we see are not the native, New England cottontails. Rather, they are the Eastern cottontail, a closely related species. From Mass Audubon: "The New England cottontail has a darker back, a broad black stripe on the outer edge of the ear, and usually a black spot between the ears. The eastern cottontail differs only slightly, with a paler coat, a cinnamon-rust nape, and a narrow black margin extending along the front edge and tip of the ear. It sports a white or light brown spot on the forehead." Another subtle difference between the two is that Eastern rabbits have larger eyes, the better to see approaching predators.  

The two species, despite physical similarities, inhabit different ecologies and do no interbreed. The natives, now scarce, prefer thickets and young forests, as might occur after a farm is abandoned or in areas where fire has cleared older growth. Eastern cottontails prefer more open space, such as in suburban habitat.

As to why Eastern rabbits are here, their history was not a natural expansion from the central Atlantic states. Rather, tens of thousands of rabbits were deliberately introduced 1920-1940 to give hunters another species to shoot at.    

As to why more rabbits now, this may be a convergence of weather and change in predators. Last year's winter was mild and low snow, all contributing to better winter survival of rabbits, which do not hibernate. Spring being earlier than usual meant breeding started sooner. Easter cottontails can reach sexual maturity in as short as three months, so this year we are already into the second generation and by October will be overrun by the third.

Eastern  cottontail on green lawn, Click on photos to enlarge.
While coyotes are a natural predator of rabbits, a greater consequence of coyotes in the area is the now rarity of people letting their pet cats outdoors. Ten years ago, many outdoor cats. Then a period of "Lost cat" signs. Now, far fewer outdoor cats. In addition, the prolonged drought has reduced the populations of raccoons, skunks and opossums. All of these are predators of young rabbits.     
Rabbits and kin can be called other than "rabbit." Males are bucks, females are does. There's bunny, as in bunny rabbit, or coney, an archaic term still heard in parts of Great Britain, also mentioned as a possible name origin for Coney Island, New York. We hear hare and jack rabbit for related species, also "cottontail" as appearance-descriptive for our local rabbits. Culture and children's literature gave us Playboy Bunnies, the Easter Rabbit, Peter Rabbit, Br'er Rabbit, Bunnicula and The Velveteen Rabbit.

Movie-named rabbits include Harvey, Roger Rabbit, the Killer Rabbit of Caerbannog (Monty Python and the Holy Grail), the Were-Rabbit (The Curse of the Were-Rabbit) and Frank (Donnie Darko). Rabbits were featured in Watership Down and Alice in Wonderland. And lest we forget, there is Bugs Bunny, the Ur-rabbit of fictional rabbitdom. In 1997, he was the first animated character to appear on a U.S. postage stamp. Rumor has it that Mickey Mouse could have been first, but Disney wanted a royalty.

A rabbit in possession of all of its feet.
Rabbit's foot for luck? People still remember when it was not rare to carry a rabbit's foot keychain, preferably made from the left hind foot of a rabbit killed in a graveyard. It was for luck, especially gamblers' luck, and to ward off evil, with a history linked back to both European and African traditions. Rabbits' feet can still be found for sale on the internet, either in natural color, dyed various colors, or faux rabbit feet fashioned from fake fur. But as one pundit noted, "Depend on the rabbit's foot if you will, but remember it didn't work for the rabbit."

Another memory of rabbits' feet - back in the 1970s there were several butchers' shops in Little Italy, Boston, that displayed skinned rabbits in the window - headless - but with the feet still covered with fur. I asked one butcher why the feet were left intact. He paused for a moment, then answered, "That's how you know I'm not selling you a cat." There is a German proverb which suggests this was not a joke. It goes, "Kopf weg - Schwanz weg - Has!" translates as "Head away - Tail away - Rabbit!"

Not in the newspaper column: 

The proverb means cut the head and tail (and feet) off a cat and you've got a rabbit. Famines and sieges have often led to people eating dogs, cats and rats; cats eaten often enough that during World War II there was a slang term, "roof rabbits," or in German, "dachhasen." During the 1870-71 siege of Paris, the residents consumed all the horses in the city, then dogs, cats, what rats they could catch, and finally the zoo animals, finishing with a pair of elephants.   

On a different note, why do rabbits have white tails? There is an interesting theory that having a conspicuously visible tail can help with evading predators. For some species - birds especially - a colorful tail on the male birds improves their mating success. Peacocks are an extreme example. This is not true for rabbits - both sexes have white tails and tail display not involved in courting nor in male-to-male competition for territory or mating rights. 

The key to the answer appears to be that when rabbits flee a predator such as a fox or coyote they are frequently changing directions. Visually focusing on the white tail may cause the close-following predator to guess wrong on which way the rabbit is turning, because the white of the tail lags behind which way the front of the body turned. The same probably applies to white-tail deer escaping from pursuing mountain lions, although deer also use tail raising to alert other deer in a group of possible danger. One way of testing the theory on rabbits would be to trap all rabbits in one area and apply hair dye to half. Then, in the fall re-trap rabbits and see which half had better survival.

No comments:

Post a Comment