The Northern Gannet (Morus bassanus) is a seabird and is the largest member of the gannet family, Sulidae. It has the same colors as the Australasian Gannet and is similar in appearance. Nesting in colonies as large as 60,000 pairs, this bird is a spectacular high-speed diver.Young birds are dark brown in their first year, and gradually acquire more white in subsequent seasons until they reach maturity after five years.Adults are 81–110 cm (32–43 in) long, weigh 2.2–3.6 kg (4.9–7.9 lb) and have a 165–180 cm (65–71 in) wingspan. Before fledging, the immature birds (at about 10 weeks of age) can weigh more than 4 kg (8.8 lb). Their plumage is white with black wing tips. The bill is light bluish. The eye is light blue, and it is surrounded by bare, black skin. During breeding, the head and neck are brushed in a delicate yellow.
When feeding, these birds are spectacular high-speed divers, plunging into the ocean from a height of 10–40 metres (33–130 ft), with their bodies straight and rigid, wings tucked close to the body but reaching back, extending beyond the tail, before piercing the water like an arrow. Their nearly vertical dive can reach speeds exceeding 100 km/h (60 mph) before entering the water, allowing them to penetrate 3–5 m (10–16 ft) below the surface, and occasionally swimming down to 12–15 m (40–50 ft). If the dive was successful, gannets will swallow the fish underwater before surfacing, and will never fly with the fish in its bill. Although they are strong and agile fliers, they are clumsy during takeoffs and landings.They mainly eat fish 2.5–30.5 cm (0.98–12.0 in) in length which gather in groups near the surface. Virtually any small fish (roughly 80–90% of their diet) or other small pelagic species (largely squid) will be taken opportunistically. Various mackerel, cod, smelt, and herring species are most frequently taken.
for different pics.....
No comments:
Post a Comment