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Re: attack on dinosaur--horrific video



There are a number of observed behaviors that might
have helped dinosaurs avoid egg/nestling predation. 
Alligators build self-heating nests and guard them
until the eggs hatch.  After that, they guard their
young.  Horner observed that a hypsilophodont rookery
was on an island.  Even if one dino of a breeding pair
had to sit the nest, a mate could help protect it. 
These behaviors could probably evolve quickly under
the selective pressure of nest predation.

I saw a video of small birds that had apparently
recently developed the behavior of attacking larger
nesting birds, so it's not just mammals.

As I recall, the sclerotic ring served as a night
vision device, and some dinos had large eyes for
preying on night-active critters like mammals.

Glen Ledingham

  
--- john bois <jbois@verizon.net> wrote:

> Eike wrote:
> > In the currect case, it's island
> > naivity; these birds simply know no terrestrial
> > predators, and haven't for a long time.
> 
> With respect...the critical point the video makes
> (as it relates to a 
> general dinosaur susceptibility to predation) is
> that an incubating parent 
> is likely to suffer distasterous predation because
> of a couple of nesting 
> imperatives: if you leave the nest you lose your
> eggs/hatchlings--i.e., you 
> lose either way; and it is almost impossible to
> defend a nest at night. 
> Neither of these points relates to naivety--rather,
> they relate to the eye 
> physiology of (in this case) mammals vs. birds; and
> (in the case of large 
> non-avian dinosaurs) an inability to nest in remote
> or hidden locations (a 
> strategy the albatross had successfully employed
> until the dreaded mouse 
> colonization).
> For me, the now-known diversity of Late K mammals
> ranging into racoon-size, 
> and the general tendency/rule of organismal
> exploitation of available 
> resources, leaves the hypothesis of large scale nest
> predation (as seen by 
> almost all extant large egg layers) with two
> questions: could non-avian 
> dinosaurs see at night?; and could non-avian
> dinosaurs escape predation by 
> nesting in locations remote or hidden from small
> nocturnal predators. 
> 
>