Tuesday, April 27, 2010

The Grand Old Goose of York

A guest post by Ken.

Whilst on a sojourn recently in Yorshire I took a trip to York only to come upon a goose. The greylag goose (Anser anser). I was walking along a canal with friends of mine and there it was. Later I saw two more along with eight offspring.

Greylag goose (Anser anser)

Greylag geese are monogamous, exist in a female-bonded social system, similar to primates, and their fledged offspring stay with them until the next breeding season. Dominance rank in flocks of geese is determined by the active social support family members or pair partners give to each other. Parents provide active assistance for their offspring in encounters with other members of the flock but females and juveniles of several species of geese involved in agonistic behaviour were more successful when a male partner or parent was present but did not actively interfere. If parents fail to produce young, subadults (a bird with some adult traits but not yet sexually mature) may rejoin them in summer after molting is completed and thus form a 'secondary family' and this may be seen as an alternative tactic for the subadult geese where they associate with former allies when no suitable mate is available. Scheiber et al. suggest that retaining a family unit might allow both the parents and the offspring to preserve a high social status and also enjoy the benefits of a social alliance such as the males winning agonistic interactions and the females having a decreased level of CORT (lower stress levels). [Isabella B.R. Scheiber, Kurt Kotrschal, Brigitte M. Wei[ss], Benefits of family reunions: Social support in secondary greylag goose families, Hormones and Behavior, Volume 55, Issue 1, January 2009, Pages 133-138].

Greylag goose family

Whilst taking the above picture the nearest adult goose hissed quite loudly at me. I only wanted to say 'Hello'. Although greylag geese can be hand-raised and see humans as allies in their agonistic interactions this was certainly not the case here. I was not part of their family.

I walked on.

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