[no subject]

[farlow@CVAX.IPFW.INDIANA.EDU]

Some of you may recall my asking about the evidence for a predator/prey
relationship between the big eagle Harpagornis and the moas of New Zealand.
I finally got a good answer to my question from Dr. Richard Holdaway of
the University of Canterbury.  With his permission I am posting the
information he sent me.


From: "Dr. Richard N. Holdaway" <PIOPIO@zool.canterbury.ac.nz>
Subject: Re: Harpagornis and moas
Message-ID: <236CEB375B42@zool.canterbury.ac.nz>
     
I did my thesis work on the systematics and palaeobiology of the 
eagle. During the course of that, I looked into the bird's potential 
prey by association with other taxa, by morphological interpretation, 
and by searching for direct evidence from the fossils. I predicted 
that the actual method of attack (the pictures you are referring to 
of the eagle striking at the head were done when I was at an early 
stage of the work - they are wrong) would be with one foot securing a 
hold on the rump of the moa while the other struck at the base of the 
neck. This is a standard accipitrid mode of attack for large prey. 
More than a dozen moa pelves were subsequently found with claw marks 
(varying from pin-holes to major rents) in positions corresponding to 
just such orientations (i.e. the appropriate foot for that side of 
the pelvis). There are also signs of consumption - bone removed from 
the ilial plates. The possibility of post-mortem and collection 
damage has been explored and rejected. Those forms of damage are 
easily distinguishable. The taxa represented among the damaged pelves 
included Emeus crassus, Pachyornis elephantopus and Euryapteryx 
geranoides. I have also excavated, myself, a pelvis of Dinornis 
giganteus which has the same damage which was not caused during the 
collection. I have no doubt whatsoever that Haast's eagle killed 
several moa taxa and that they were staples in its diet, and am 
preparing several papers describing the damage and predatory 
behaviour of the eagle, and its ecology and place in the New Zealand 
fauna.