Monday, March 19, 2012

Predator-Prey Behavior

Seagulls do not have any official natural predators; they do, however, have a variety of ways to protect themselves and their food. One way is “mobbing behavior” (see post on Territoriality for more info on mobbing). Although they do not have one specific predator, there have been instances in which seagulls have been attacked by sharks. Check out the fantastic picture below of this rare predetor-prey relationship! Another main predator of the seagull is the human. Although it is technically illegal to kill gulls in California according to the Federal Migratory Bird Act of 1916, many humans simply get fed up of the creatures and resort to inhumane measures of removing them. In addition to this, an estimated 100,000 marine animals are killed every year due to litter in their natural environment. When this litter is mixed with food contents, seagulls will risk their lives to obtain a meal.

Alternatively, when a seagull is a predator, it is not very picky about its prey (See forging post of more info). No gull species has one single prey that they are specialized to catch. In addition to this, no gull uses only one predatory behavior. One interesting behavior gulls do use to obtain their prey is dipping. This is when the birds sit in the water and swim in tight circles or foot paddle to bring up any marine invertebrates to the surface. Overall, a seagull does not have any specific prey or predators; however, this allows them to not only live in a variety of marine habitats but also consume almost anything they can get their beaks on!


http://en.wikipedia.org/wiki/Gull

http://www.ehow.com/about_6596844_california-seagull-law.html

http://www.derm.qld.gov.au/environmental_management/coast_and_oceans/coastal_management/beach_and_ocean_litter

Image: http://www.divephotoguide.com/underwater-photography-special-features/article/great-white-shark-seagull-underwater-photography/