Monday, February 22, 2016

Shorebirds

Shorebirds are a common sight in Floridian nature. Black skimmers “skim” the surface of the water with black-tipped bright red bills. The lower half of the bill is longer than the upper, allowing it to cut through the water and dip down to grab small fish encountered near the surface. Adult plumage is black above, white below and this striking combination, coupled with the brightly colored bill, makes it easy to spot the birds as they hunt over the water or loaf on the beach with other seabirds and shorebirds. Black skimmers, and least, royal and sandwich terns nest in colonies in the open sand on beaches, sandbars, and dredge material islands. Their nests are built on the ground and often consist of simple scrapes in the sand. (Due to habitat loss, a very small percentage of black skimmers also nest on gravel roofs!) Black skimmers rely on camouflage or group mobbing to protect their nests. Breeding colonies of black skimmers can be found along Florida’s Gulf and Atlantic coasts. Watch for them in the early evening when they actively feed, and scan flocks of loafing birds for this uncommon coastal resident.

 With its black and white plumage, long, thin red legs, and long neck, the Black-necked Stilt is both striking and delicate in appearance. It is a medium-sized shorebird with a black needle-like bill, black or dark brown upperparts, and a white breast. The iris is red, and there is a white spot above the eye. Breeding males have glossy black wings, back, and back of neck, and a pink tinge on the breast. Non-breeding males lack the glossiness and pink tinge. Adult females have a brown tinge to the back. Juveniles have brown upperparts with buff feather margins, and a white trailing edge to the wing in flight. Five species of rather similar-looking stilts are recognized in the genus Himantopus. They have the second-longest legs in proportion to their bodies of any bird, exceeded only by flamingos. This bird's habitat includes  salt ponds, rice fields, shallow lagoons, and mangrove swamps.  Black-necked Stilts most often consume aquatic invertebrates. They also sometimes eat tadpoles, tiny fish, and seeds of aquatic plants. Pairs form on wintering grounds, during migration, or on breeding grounds; pairs remain monogamous throughout the breeding season. Both sexes choose the nest site, which is often on a small island in the marsh.

Monday, February 8, 2016

Florida Marine Mammals: Seals

Seals live in the oceans of both hemispheres and are mostly confined to polar, sub-polar, and temperate climates, with the exception of the more tropical monk seals. True seals inhabit all oceans, except the Indian Ocean. Some species live in inland lakes in Siberia, Russia, and Finland. Seals forage, search for food, at sea, but haul out (get out of the water) to land to breed, molt, or shed fur, and rest. Seals eat mostly fish, but also feed on krill, squid, octopuses, and other seals. True seals congregate on land or ice to breed and molt. The males and females of some species migrate, travel, separately from breeding to foraging areas, some traveling as far south as Florida. Others species do not migrate.

Adult hooded seals have black heads and silver-gray coats with dark blotches of varying sizes and shapes across their bodies. Pups are called "blue-backs" for their coat of blue-gray on their backs and whitish bellies; this coat is shed after 14 months of age when they molt. Adult males measure around 8 feet  long and weigh about 660 pounds. Adult females are noticeably smaller, measuring around 7 feet  in length and weighing about 440 pounds. The hooded seal is unique for the elastic bi-lobed nasal cavity, or "hood", that adult males can inflate and extend from the front of their face to the top of their head. Sexually mature males also have an elastic nasal septum, which, when inflated, resembles a pinkish red balloon, to attract females' attention during mating season and to display hostility towards other males. Hooded seals usually dive for food to depths of about 325-1,950 feet  for 15 minutes at a time. Adult hooded seals feed on squid, starfish, mussels, and fish such as Greenland halibut, redfish, cod, capelin, and herring. Hooded seals live on drifting pack ice and in deep waters. Some drift far away from their northern habitat towards much warmer regions every year, but they survive best in colder climates, as heat and constant sun exposure is harmful to them.  Hooded seals are migratory and can wander long distances; they have occasionally been found as far south as Florida, California, and the Caribbean.