CORMORANTS AND THE GIPPSLAND LAKES FISHERY 107 
method. Essentially this consists of counting and recording 
the number of individuals of each species of organism in each 
stomach, quite irrespective of size. For instance, the stomach 
of a Large Black Cormorant will be distended, more than 
full, with one Black Bream (marketed) measuring 240 mm. 
(9| in.) in total length, and another similar stomach may 
contain when full about 70 Anchovies or Gobies (non- 
marketed). By the numerical method as employed by 
Serventy this would be as 70 to 1 in favour of the non- 
marketed form and therefore in favour of the Cormorants, 
whereas by the volumetric the result would be as 1 to 1. 
Because of the general disparity in size between marketed 
and non-marketed fishes, the numerical method tends to 
favour the case for the birds, but above all, it signally fails 
to give any proper conception of the part played by the 
different kinds of organisms in the birds ’ diet. On the other 
hand, the volumetric method does provide this information. 
The counting of individual organisms may be used with 
advantage to stress a point, and throughout this work a count 
has been made for the purpose of helping to interpret the 
percentage results. 
This matter has been discussed at some length since very 
little of this kind of work has yet been done in Australia, and 
it is a matter for regret that I find myself unable to accept as 
a working basis the numerical method as recently used by 
Serventy. The various methods of estimating the stomach 
contents of birds are ably discussed by W. L. McAtee in The 
Auk, xxix, 1912, pp. 449-464. 
The results of stomach examinations of the Large Black 
Cormorant for each month of 1939 for which material was 
received is set out below, with diagrams showing the volume 
percentage of each food species. Almost without exception 
the birds were collected during the afternoon and early 
evening. 
In addition to the marketed fishes already named, the 
following species of non-marketed fishes and Crustacea occur 
in the results. Only the common names are used in the text 
and diagrams, and it will be noted from the list that the term 
Gobies covers three species of these small fishes which were 
easily separated in the stomach contents, but separate treat- 
ment here does not seem warranted. 
Fishes — 
Anchovy Engraulis australis (Shaw). 
(The “Smig” of the fishermen.) 
