Re: egg-sposure (was Re: egg laying rates)

[Robert.J.Meyerson@uwrf.edu (Rob Meyerson)]

Mickey Rowe writes;

>I think the birds could be away from the nest for several minutes.

AFAIK, it could actually be more benificial for a ground nesting bird
to be away from the nest occasionally, because then the nest would
not be as likely to gain the scent of the mother, thus leading a
predator to an easy meal.  However, the parents rarely have the nest
out of sight for too long a period.

>Precocial birds don't just poof out of their eggs like Athena from
>Zeus' head...  Anyway, if I'm reading you right, I suspect that most
>such birds have some level of awareness as to when their eggs are
>going to hatch and can modify their nest sitting behavior accordingly
>(i.e. they don't have to monitor the eggs as closely just after the
>eggs have been laid since at that time they're in no danger of the
>eggs hatching unwatched).

Ehhhh, no.  Few birds ever leave the eggs completely ungarded for any
length of time.  The only reason that the egg-eating snake can get
the time to devour a whole egg is because the snake is hard to spot
in the grass, and because theparents are away hunting/feeding.  In
fact, there are a few ecological studies that suggest an inverse
relationship between the amount of parental observation and the
amount of nest destruction.  Those species that have a higher degree
of nest destruction tend to be able to lay a larger number of
clutches per breeding season to compensate.

how all this relates to dinos is anyones guess.

Rob

***
Evolution = God's kingdom with a facelift.