Maybe you should do a DNA comparison John?
Is there a chance that there's a competing variable in
harshness/availability of food? say you lived somewhere very cold,
even covered with snow, or severely limited by the cold, would that
limit the available calories and thus put an upper limit on size?
EB
On Fri, Sep 12, 2008 at 6:17 PM, John Leonard <> wrote:
> Whereas the Magpies in Tassie are smaller. If Bergmann's rule holds
> true the Tassie Magpies must be a separate species.
>
> John Leonard
>
> 2008/9/12 Graham Turner <>:
>> I remember head south to Lancefield in Victoria 6 or so years ago and being
>> amazed at the size of magpies when compared to the ones I see around the
>> Blue Mountains. Seems to work for me. Maybe its not applicable to
>> everything, but it is a 'rule' no a 'law.
>>
>> Cheers
>> Graham Turner
>>
>>
>> Bergmann's Rule
>>>
>>> From Wikipedia, the free encyclopedia
>>
>> Jump to: navigation, search
>> In zoology, Bergmann's rule is an ecogeographic rule that correlates
>> latitude with body mass in animals.[1] Broadly it asserts that within a
>> species the body mass increases with latitude and colder climate, or that
>> within closely related species that differ only in relation to size that one
>> would expect the larger species to be found at the higher latitude. The rule
>> is named after a nineteenth-century German biologist, Christian Bergmann,
>> who first formulated the rule in 1847. The rule is often applied only to
>> mammals and birds (endotherms), but some researchers have also found
>> evidence for the rule in studies of ectothermic species.[2] Bergmann's rule
>> is controversial amongst researchers and its validity has often been called
>> into question,[3] and there is division amongst scientists about whether the
>> rule should be interpreted to within species variation or among species
>> variation.[1] Although several mechanisms have been suggested to explain the
>> rule there is no clear explanation for why the pattern exists.
>>
>>
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