Friday, 19 July 2013

Processing pellets

After the colony clean-ups, I had amassed a large number of regurgitated pellets (anything that the birds are unable to digest gets formed into a pellet and regurgitated) which needed to be dealt with! The various bags of pellets were moved into my kitchen, which has also become my office. At the time, and currently, I am uncertain as to the best way to dissect and quantify the contents of the pellets, and am in the process of reading other published papers to see what methods they used, and how detailed their data was. In the meantime though, the pellets needed to be processed and frozen to stop, or at least slow, any fungal growth and decomposition. After purchasing and numbering 400 ziplock bags (surely enough!) I started processing the pellets. Each pellet was assigned a number, which relates to the date and location it was collected from, and was photographed, dimensions measured and weighed, then bagged and frozen. I then had to buy more bags. At 750 pellets processed, and many more to do, Mark and I decided that I should finish the bag I was busy with and discard the rest; this number is already far more than most published papers incorporate, and the breeding season hasn’t even started yet! The final count is 798 pellets, frozen and awaiting dissection. It has been so interesting to go through the pellets that were collected, a scarily large proportion of them had plastic, glass shards and tin foil in them. Something that fascinated me was the pellets that looked better suited to an owl than a gull, as it is clearly the remains of a rodent, a regurgitated globule of fur and bones. It was reassuring to also find many pellets with fish bones and scales, as well as shells, part of their natural diet. The true story will become more apparent as I start the dissections, but for now, an interesting glimpse into their diet.

Many pellets had fragments of glass in them.
Fur and bones, probably rats.
A variety of shells in the pellets.
All sorts of urban sources of 'food'.

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