[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
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.
--- john bois <email@example.com> 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
> 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.