Tyrannosaurus rex: hunters rule, scavengers go hungry (free pdf)

[bh480@scn.org]

From: Ben Creisler
bh480@scn.org


This item was in various news stories late yesterday. 
Here's the citation and link to the free pdf in case they 
have not been posted yet:

Chris Carbone, Samuel T. Turvey and Jon Bielby (2011)
Intra-guild competition and its implications for one of 
the biggest terrestrial predators, Tyrannosaurus rex.
Proceedings of the Royal Society B (online publication)
doi: 10.1098/rspb.2010.2497 
http://rspb.royalsocietypublishing.org/content/early/2011/
01/20/rspb.2010.2497.full.pdf+html


Identifying tradeoffs between hunting and scavenging in 
an ecological context is important for understanding 
predatory guilds. In the past century, the feeding 
strategy of one of the largest and best-known terrestrial 
carnivores, Tyrannosaurus rex, has been the subject of 
much debate: was it an active predator or an obligate 
scavenger? Here we look at the feasibility of an adult T. 
rex being an obligate scavenger in the environmental 
conditions of Late Cretaceous North America, given the 
size distributions of sympatric herbivorous dinosaurs and 
likely competition with more abundant small-bodied 
theropods. We predict that nearly 50 per cent of 
herbivores would have been within a 55?85 kg range, and 
calculate based on expected encounter rates that 
carcasses from these individuals would have been quickly 
consumed by smaller theropods. Larger carcasses would 
have been very rare and heavily competed for, making them 
an unreliable food source. The potential carcass search 
rates of smaller theropods are predicted to be 14?60 
times that of an adult T. rex. Our results suggest that 
T. rex and other extremely large carnivorous dinosaurs 
would have been unable to compete as obligate scavengers 
and would have primarily hunted large vertebrate prey, 
similar to many large mammalian carnivores in modern-day 
ecosystems. 


Links to news stories and blogs with reactions and 
comments:
http://www.redorbit.com/news/science/1985428/study_dispute
s_claims_that_t_rex_was_a_scavenger/
http://www.wired.com/wiredscience/2011/01/tyrannosaurus-
rex-scavenger/
http://www.msnbc.msn.com/id/41274041/ns/technology_and_sci
ence-science/