Reproductive Parameters, Chick Growth and Adult ‘Age’ in Australasian Gannets Morus serrator Breeding in Port Phillip Bay, Victoria, in 1994–95

Preliminary investigation of the costs of incubation in the Australasian Gannet (Morus serrator) breeding in Port Phillip Bay, Victoria

“…On each visit, attempts were made to measure bill length (dial callipers, 200 mm ± 0.1 mm) and body weight (spring balance, 0-1 kg ± 5 g, or 1-5 kg ± 25 g) of as many chicks as possible, such that each chick was weighed at least five times between hatching and ~60 days old. Previous studies at Popes Eye and elsewhere have shown that growth of Gannet chicks is relatively slow to 20 days of age, and then becomes rapid and almost linear to 60 days old, followed by a decrease in growth rate (Wingham 1984b;Gibbs et al 2000). As a consequence, particular attention was paid to the size of chicks half-way through (at 40 days old) and at the end of (at 60 days old) the linear growth phase.…”

“…Some 160 pairs of Gannets were nesting at Popes Eye during this study, mainly on the platforms and walkway (~150 pairs), with a small number breeding on the concrete structure and on rocks immediately north and south of the platform. The timing of breeding, breeding success and diet of Gannets at this colony has been regularly monitored, as have aspects of the growth of the colony and site-fidelity of adults (see Norman and Menkhorst 1995;Norman et al 1998;Gibbs et al 2000;Bunce 2001aBunce , 2001bNorman 2001;Bunce et al 2002Bunce et al , 2005, who also provide further details of the site and its location).…”

“…Further, eggs were only exchanged between nests in the more central areas of the colony where birds tend to be older and more successful (e.g. Gibbs et al 2000;Bunce et al 2005).…”

“…The Gompertz equation was used since it is the most appropriate curve to fit growth data for Gannet chicks (Wingham 1984b;Navarro 1991;Gibbs et al 2000;Bunce 2001a). The mean parameters (A, K, and I) within treatment groups were compared using ANOVA.…”

Subcolony variation in phenology and breeding parameters in little auk Alle alle

“…Hatching success is often lower in the nests of young birds (Koenig 1982) and of individuals in poor body condition (Yorio and Boersma 1994) or with high stress levels during incubation due to prior nutritional stress (Kitaysky et al 2007). Young and/or 'low-quality' individuals often occupy worse, peripheral parts of colonies (e.g., Spurr 1975;Mínguez et al 1998;Gibbs et al 2000). The southern part of Høystakken is a peripheral part of the colony.…”