Re: Reproduction and Environment

[Dann Pigdon <dannj@alphalink.com.au>]

On Thu, 06 Apr 2006 03:19:27 +0000, Dinosaur World wrote
> I know that certain animals time their reproduction so that their 
> young are born to coincide with environmental events that are 
> beneficial to babies, but what is the catalyst that starts the 
> reproductive behavior? 

Researchers have certain theories about particular species, but on the whole 
it's still a mystery. The start of the monsoon season in northern Australia 
is often predicted based on crocodile nesting behaviour. As to HOW the crocs 
know exactly when the rains will come is unknown - but they have proved such 
reliable indicators that people follow their lead anyway.

> And if this ?catalyst? did not occur, would that reduce or stop all 
> together the reproduction of that particular species for that season?
> 
> Are there any examples of modern animals whose reproductive behavior 
> is altered by environmental changes? Could environmental changes 
> have affected dinosaurs the same way?

Very recently a study concluded that the cooling trend in eastern Antarctica 
is having a severe impact on the breeding of seabirds. They are having to 
delay their breeding until the weather warms up sufficiently (they now start 
on average 9 days later than they did in the mid-20th century). This means 
that chicks are maturing later, and they may miss out on the peak 
availability of foods such as krill.

The birds are adapting, however. One strategy they've used so far is to 
shorten their mating rituals, so although they arrive 9 days later than in 
previous ddecades, they acually nest only 2 days later than normal (so mating 
rituals have been shortened to take 7 days less than previously).

http://sciencenow.sciencemag.org/cgi/content/full/2006/403/1

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Dann Pigdon
GIS / Archaeologist         http://heretichides.soffiles.com
Melbourne, Australia        http://www.geocities.com/dannsdinosaurs
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