A significant decrease in mean egg-shell thickness since 1945 was found in two of the six Australian Falco: Peregrine (F. peregrines) (10%) and Hobby (F. longipennis) (2%). The eggs of the other three species, in certain localised areas only, showed significant thinning. The six Australian Falco conform to the general 'rules' influencing the degree of egg-shell thinning; that is, those pertaining to diet and distribution. At least one species, the Peregrine, could be expected to be suffering localised decreases in productivity due to breakage of thin-shelled eggs.
|Number of pages||4|
|Journal||International Council for Bird Preservation|
|Publication status||Published - 1985|