O. Kiely et Aa. Myers, Grey seal (Halichoerus grypus) pup production at the Inishkea Island Group, Co. Mayo, and Blasket Islands, Co. Kerry, BIO ENVIRON, 98B(2), 1998, pp. 113-122
Citations number
48
Categorie Soggetti
Biology
Journal title
BIOLOGY AND ENVIRONMENT-PROCEEDINGS OF THE ROYAL IRISH ACADEMY
The grey seal breeding assemblies on the Inishkea Island Group and Blasket
Islands in western Ireland were studied in 1995 and 1996. A census of pup p
roduction in each area provided data on the timing of breeding and site sel
ection at these island groups in addition to birth and mortality parameters
. An estimated 154 pups were born at the Inishkea Group in 1995 and 155 pup
s at the Blasket Islands in 1996-97. These figures correspond to minimum al
l-age population estimates of 539-693 and 543-697 animals, respectively. Th
ese minimum estimates are similar to those derived in previous work at thes
e islands, suggesting little change in the breeding population size at thes
e colonies since 1983. Observed mortality was approximately 7.8% at the Ini
shkea Group and 2.6% at the Blasket Islands, though the true mortality may
have been higher. Changes in breeding site use since 1980-83 were observed
at the Inishkea Group in 1995. These are thought to be a result of past hum
an interference. More effective coverage of the breeding season and long-te
rm monitoring of these sites would contribute more accurate estimates and f
acilitate the determination of population trends.