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Re: Nesting strategies (was Big = Old = Advanced?)
Bryan R. Stahl writes;
>But would it follow the wolf - coyote pattern, or would it take an African
>style pattern, i.e. lion - jackal, hyena - cheetah, or lion - hyena? The
>wolf - coyote pattern would seem to apply to the different species of
>tyranosaurids, with the smaller being driven into more marginal areas by
>the larger. The African pattern seems closer to the dromeosaur -
>tyrannosaur idea. The idea being, would they directly compete like lions
>and hyenas(which ever side has the advantage driving the others off), would
>the dromaeosaurs scavenge like jackals, or would the tyrannosaurs plunder
>the dromaeosaur kills like hyenas and lions do to cheetahs?
To start off, let's define each of the patterns you recognize. The lion-jackal
pattern is where the smaller species tends to come in after the big one has
finished with it's kill. The hyena-cheetah pattern is the exact opposite,
larger species stealing the smaller species kill, so let's consider this to be
the flip side of the same coin. The lion-hyena pattern deals with two species
that are evenly matched in size, strength, and power.
In a Cretaceous setting, the hyena-cheetah pattern would fit best with
tyrannosaurs and dromaeosaurs. The smaller theropods would most likely be
driven off a kill by the larger theropod. I'm not sure what, if any, effect
that pack living would have on this pattern, but I suspect that even a good
sized flock would be driven off by the tyrannosaur (is it safe to assume that
there was an inverse relationship between the size of the pack and the size of
the species?). The way that the lion-hyena pattern would come into play is if
there were two species of tyrannosaur, or a tyrannosaur and an albertosaur,
living in the same area.
I suspect that each species of the larger theropod, or each individual/pair
(depending on your viewpoint), had a distinct home range that could be easily
defined. How the smaller theropods related to this is anyone's guess. The
smaller theropod could pose a serious threat to the larger theropod's chicks,
and so the smaller ones would be driven off. Then again, if the food supply
was high enough, the larger theropods might tolerate the presence of the
smaller ones (especially the troodontids). There is also a question of whether
the two species operated under different niches, which would cut down on how
they related to each other; perhaps some dromaeosaurs specialized in
This is where paleontology gets really tricky: when we try to interpret the
ecology of the time.
It would be really interesting to see if we can interpret home ranges from the
fossil record. Does anyone know if larger theropods are found nearby areas
where the smaller ones have been found.
"Keep your stick on the ice."