Thursday 5 February 2015

Dining on Dublin's Docks

Brent Geese have become a very familiar site in Dublin City in recent years often turning up in all sorts of places.Our thanks to Richard Nairn of Natura Environmental Consultants for his insight into the movements of Brent Geese within Dublin Port.



"Brent Geese are now using the inner parts of Dublin Port on a regular basis.  As the winter progresses,  their natural food resources such as eelgrass and green seaweeds become scarcer on the mud and sandflats throughout the bay. The geese seem to have been forced to seek out other feeding areas including golf links, sports pitches and public parks with over a hundred such sites now used around the city.  A recent development has been the tendency of some geese to favour feeding on spilled agricultural products on the quaysides in Dublin Port.   


Feeding flock by the quayside - Richard Nairn

They swim on the River Liffey or in the Alexandra Basin (a deep mooring area for large ships within the port) until any disturbance has passed and then fly up onto the quays where they feed intensively on maize and soya meal among large flocks of pigeons and smaller numbers of gulls.  So far as we are aware this behaviour has not been recorded anywhere else in their range which includes sites in Canada, Iceland and throughout Ireland. I have been monitoring these geese closely over the last few winters and  peaks of up to 450 geese using this source of food have been recorded. 

Brent Geese next to Alexandria Basin - Richard Nairn


 Among them are some colour-ringed geese and the large numbered codes on these rings show that a core group of up to ten individual birds are using the Port on a regular basis, including over several winters.  This suggests that some geese have learned to exploit this food and others then follow them in to share the spoils.

Ringed Brent Goose - Richard Nairn


You can follow the fortunes of the geese on the blog posts of the Irish Brent Goose Research Group at http://irishbrentgoose.blogspot.co.uk/."

2 comments:

  1. There are so many cases, globally, where birds turn to high-energy food where available; my first association goes to the wintering ruffs of the Sahel area. But there is an even closer example: In October, when the sugar-beets are harvested in Skåne, S. Sweden, barnacle geese collect by thousands to devour the sweet-tasting leftovers (they used to be given to the milk-cows earlier, but we have so few cows today). The ensuing fattening may be one reason for the widespread wintering of barnacle geese in South Sweden in later years.

    ReplyDelete
  2. As early as 1986, Vitousek, Ehrlich, Ehrlich & Watson wrote in Bioscience: We estimate that organic material equivalent to about 40 % of present net primary production in terrestrial ecosystems is being co-opted by human beings each year. That amount is well over 50 % today, and increasing all the time, so where is animal evolution to head?

    ReplyDelete