Re: How far below the surface does the Northern Fence Lizard spend the winter?

Hi there,
Here is the answer to your question and also some very interesting 
information concerning Lyme Disease and the Fence Lizard.  There are also 
some neat links where you can get further information about these
neat little lizards.

They essentially drive their bodies with vibratory movements from one side
to the other into the soil and they're down an inch or two. http://www.pulseplanet.co
m/Dec98/1774.html

University of California at Berkeley scientists may have found the reason 
there is less tick-borne Lyme disease in California than in the eastern 
United States, where it was  first discovered and given its name.

Scientists have found that ticks who feast on the blood of the
common western fence lizard are purged of Lyme disease bacteria
within their gut. It is thought that a protein in the lizard's blood
destroys the bacteria that would otherwise thrive in the belly of the
tick and would later be transmitted to humans. The protein is yet
to be identified.

Robert Lane, an insect biologist at UC Berkeley and his colleague
conducted laboratory experiments using young Lyme disease-infected ticks 
and fence lizards. The ticks are about the size of a poppy seed in the 
nymphal stage, during which they feed on the blood of the lizards. Commonly 
found are 30 o 40 ticks at one time sharing the blood of a single fence 
lizard. 
Though the infected adult female ticks threaten to transmit 
Lyme disease to humans, the smaller nymphal ticks are most 
jeopardous because they are hard to find and also capable of 
transmitting the disease.

Eight years ago, Lane had determined that lizards appeared               
immune to Lyme disease even though infested with tick nymphs.
His latest research and experiments help explain why. 

The experiments first ruled out that antibodies produced by
the lizard's immune system could neutralize Lyme disease
bacteria. 
Test tube experiments revealed that Lyme disease 
bacteria soaked with lizard's blood died within one hour, 
compared to samples grown in mouse blood which lasted three 
days.

Researchers heated lizard blood to the boiling point and
discovered it no longer killed the bacteria in the test tube.

Lab tests showed that after infected nymphs fed on lizards
and then metamorphosed into adult ticks, they were no longer
infected.

The sum of these results indicates what Lane called 
a "spirochete-killing factor" which is likely a large 
protein.
Researchers are now attempting to determine the 
exact nature of the Lyme disease-killing protein. Once found, the 
hope is it will be useful in creating a treatment for the disease.

California health officials have long been both 
pleased and puzzled by the low incidence of Lyme disease in the state 
despite an abundance of ticks. Lane reiterates that eastern 
regions with higher incidence of Lyme disease are areas without 
fence lizards.

The percentage of infected deer ticks in high Lyme 
disease areas such as Connecticut is 30 to 60 percent. The 
percentage of black-legged ticks, the closely related cousins that 
carry Lyme disease in California, is only 1 to 2 percent and 
only as high as percent in Mendocino county where Lyme disease is 
most prevalent in California.

In California, about one in every 200,000 persons is 
infected with Lyme disease. The rate in Connecticut is 100 times 
higher.

                       REFERENCE:
                       San Francisco Chronicle, 4/17/98

 http://www.vom.com/sec/fence.htm http://www.sdnhm
.org/fieldguide/herps/scel-occ.html http://oxbow.colstate.edu/lizar
d.htm

Thanks for taking the time to send in a question to the Mad Scientist 
Network.

June Wingert
Mad Scientist