1976 September: Phillip Island. Concerns about thin penguin shells. Pesticide: DDT

12 September 1976

Letter to Director
Fisheries and Wildlife Division

Thin Shells on Penguin Eggs

This weekend, during the routine check of penguin burrows at Phillip Island, we found three eggs with a series of small breaks where the shell had been depressed. When marking one egg with a pen, the point broke through the shell.

In the previous eight seasons during which we have carried out this routine work, we have not found one egg similarly damaged out of the many hundreds handled. The shell is normally hard. I believe this to be necessary because much of the courtship of a pair is carried on in the burrow and the eggs are subjected to rather rough treatment.

The three eggs were in the study area where at the moment there are 19 altogether. We did not search for other eggs in surrounding areas, merely contenting ourselves with feeling for then in the burrow to ascertain whether the occupants were breeding.

Perhaps these three eggs are not significant of a general thinning of shells through DDT contamination, but I pass on the information in case you wish to follow it up in some way. The eggs have been left in the nests but could be located without difficulty should you wish to examine them.

Yours sincerely


Penguin Study Group