Princeton's WordNet(3.00 / 1 vote)Rate this definition: 1  opacity(noun) the phenomenon of not permitting the passage of electromagnetic radiation. 2  opacity, opaqueness(noun) incomprehensibility resulting from obscurity of meaning.
The Oystercatcher is a species of bird that lives around Europe and Asia. They usually eat shellfishes that are found on beaches and mud.The Eurasian Oystercatcher uses its sharp bill to open the shells of oysters and mussels.It cuts the muscle between the two halves of the shell together, or it crashes the shell against a rock and eats the oyster inside.ith bills like that, oystercatchers are dangerous opponents for other birds. They can fight off predators, and often raid other birds to steal their catches. They attack other birds at an average of five-minute intervals during low tide. They get as much as 60% of their food by theft.
Microhabitat For Foraging. Foraging is restricted to intertidal sand or mud flats, oyster or mussel reefs and less commonly along rocky shorelines. Oystercatchers often feed along the edge of receding tide on sand or mud flats but in shellfish beds they forage while mussels or oysters are still submerged (see below).utrition and Energetics. In a study of breeding season time budgets (Nol 1985), birds spent 10%, 19%, 10.5%, and 23% of their time searching for food in the pre-laying, laying, incubation, and chick-rearing periods, respectively. No significant differences between the sexes.