Seagull Oil
by Deborah Benoit
Title
Seagull Oil
Artist
Deborah Benoit
Medium
Photograph - Original Photography By Deborah Benoit
Description
Charadriiform birds drink salt water as well as fresh water, as they possess exocrine glands located in supraorbital grooves of the skull by which sodium chloride can be excreted through the nostrils to assist the kidneys in maintaining electrolyte balance.
^^^^^^^^^^^^^^^^^^^^
Gulls are highly adaptable feeders that opportunistically take a wide range of prey. The food taken by gulls includes fish and marine and freshwater invertebrates, both alive and already dead, terrestrial arthropods and invertebrates such as insects and earthworms, rodents, eggs, carrion, offal, reptiles, amphibians, plant items such as seeds and fruit, human refuse, and even other birds. No gull species is a single-prey specialist, and no gull species forages using only a single method. The type of food depends on circumstances, and terrestrial prey such as seeds, fruit and earthworms are more common during the breeding season while marine prey is more common in the non-breeding season when birds spend more time on large bodies of water.
********************
In addition to taking a wide range prey items gulls display great versatility in how they obtain prey. Prey can be obtained in the air, on water or on land. In the air a number of hooded species are able to hawk insects on the wing; larger species perform this feat more rarely. Gulls on the wing will also snatch items both off water and off the ground, and over water they will also plunge-dive to catch prey. Again smaller species are more manoeuvrable and better able to hover-dip fish from the air. Dipping is also common when birds are sitting on the water, and gulls may swim in tight circles or foot paddle to bring marine invertebrates up to the surface. Food is also obtained by searching the ground, often on the shore among sand, mud or rocks. Larger gulls tend to do more feeding in this way. In shallow water gulls may also engage in foot paddling. A unique method of obtaining prey to gulls involves dropping heavy shells of clams and mussels onto hard surfaces. Gulls may fly some distance in order to find a suitable surface on which to drop shells, and there is apparently a learnt component to the task as older birds are more successful than younger ones. While overall feeding success is a function of age, the diversity in both prey and feeding methods is not. It has been suggested that the time taken to learn foraging skills explains the delayed maturation in gulls.
********************
Gulls have only a limited ability to dive below the water in order to feed on deeper prey. In order to obtain prey from deeper down many species of gull feed in association with other animals, where marine hunters drive prey to the surface when hunting. Examples of such associations include four species of gull feeding around plumes of mud brought to the surface by feeding Grey Whales,and also between Orcas(largest dolphin specie)and Kelp Gulls (and other seabirds).
Uploaded
November 18th, 2013
Statistics
Viewed 490 Times - Last Visitor from New York, NY on 04/19/2024 at 9:29 PM
Embed
Share
Sales Sheet
Similar Images
Comments (30)
Recently Viewed
