HI friends,
I just happened to be browsing through Coates and Bishop's A Guide to the
Birds of Wallacea. Under Masked Lapwing V.miles (p.286) they state: "In the
recent literature, the well differentiated forms miles and novaehollandiae
are treated as races of a a single species because they hybridise in at
least two areas where they meet in E.Australia. However, there seems to be
little evidence of intergradation and they may best be considered separate
species,as formerly Masked Lapwing and Spur-winged Lapwing." I have checked
HANZAB on the question of intermediates, and they state on page 956 of Vol.2
that intermediates are known from Townsville but only miles occurs in Cairns
and only novaehollandiae occurs in Mackay. So we may be looking at a narrow
zone of intergradation. And according to modern views of the significance of
an area of intergradation, a narrow zone of intergradation is thought to
constitute evidence of two distinct species. This is particularly true if
large numbers of pairs breeding "true" occur in the zone of intergradation.
Also I can see nothing in the page of to what extent taxa breed true around
Townsville and to what extent they interbreed. The other area of
intergradation is supposed to be the Lake Eyre catchment area. The South
Australian Museum holds many intermediates, but it is not known how much
Shane Parker might have been biassed in his collecting.
Do any of you have any opinion on either the Townsville or the Lake Eyre
situation?
Dr John Penhallurick
86 Bingley Cres
Fraser A.C.T. 2615
Australia
email:
Phone: Home (612) 62585428
Mobile:0408585426
Please visit my website:http://www.worldbirdinfo.net
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