4 July 2016

Full day of seabirds (and some cannibalism)

You know it's seabird time of year when you're heading out ringing for the day and your roof rack looks like this! Add to that a back seat full of paddles, buoyancy aids, drybag, VHF radio and an assortment of rings and colour rings and we were in for a long day...

First port of call was to take two boats over to Mullion Island to try to track down some of the 203 Great Black-backed Gull chicks/eggs we'd counted earlier in the year. Very few birds make it to a ringable size though, but with a record count this year hopes were high. The vegetation was, as ever, challenging and wading through the mallow and sea kale looking for chicks is a laborious job.

Even large chicks are remarkably good at hiding in low vegetation
True to form we found very few birds, which is always a bit depressing; a full sweep of the island found just 13 birds! These were all a good size to ring and colour ring, so it'll be interesting to see where these birds go wandering.

Some birds aren't quite so good at hide-and-seek though

Part of the reason so few birds survive to this stage was evident all around the island though, with at least 16 relatively freshly-dead chicks found. Some of these were pretty well-grown so it does look like predation (or more accurately cannibalism) remains a driver of the low productivity on the island. We're not sure how commonplace this is, but it doesn't seem to be the best strategy for a colonial-nesting bird!

Once we were back over from Mullion, we headed straight round to Praa Sands for the long paddle round to Trewavas Head to the second of our Kittiwake sites (only accessible by kayak). Unfortunately, the swell was way higher than forecast, so it wasn't safe to land and in any case the tide was really high which would have made accessing nest sites rather treacherous! This isn't the easiest of jobs at the best of times, as kayaking round the headlands with a double-ladder strapped to the side of your kayak is tiring to say the least. Makes landing interesting as well and I must admit we did get barrelled by a wave coming back in to Praa Sands.

Last job of the day (after an impromptu ringing group BBQ in the evening sun) was to make the most of a calm, new moon night to get nets up for Storm Petrels. The first net round before midnight produced over 25 birds so we knew we were in for a busy night, but sadly the Cornish mizzle came in at 1am and we had to beat a hasty retreat before the rocks got too slippy. But although we'd not made it to the busiest time of the night the total of 55 new birds was pretty good. It was a bit surprising to find these were all new birds, so we'll just have to go out again on Tuesday night and hope to recatch some ringed birds...


  1. I wonder why this happens on Mullion but not on Looe. We had 86 pairs and cr 90 chicks. Are there rats on Mullion perhaps?

  2. Yes I suspect that this is predation by other species.