26 June 2020

Mullion gull numbers

With the last of the (supposedly) calm seas for a while, we took the chance to get over to Mullion Island to ring any surviving Great Black-backed Gull chicks. At the start of the month we counted at least 59 nests with 146 eggs/chicks, but we know that survival is incredibly low to fledging, so we never know what to expect.

Worryingly the first chick we found on the island was tiny, perhaps only a week old and far too small to ring. With most chicks on Looe Island a good size now (we visited two days ago to ring them there) we wondered if Mullion birds were nesting far later and we'd struggle to find any chicks big enough to ring. The remainder of the island was a mixed bag though, with some nests still with eggs, one just in the process of hatching.


However, we did also find enough larger chicks to keep us occupied and in the end we colour-ringed 14 birds. This is still only 10% of the eggs/chicks we counted three weeks ago. but seems typical of recent years. We'll make a return trip in a couple of weeks time to see if the remaining chicks have survived, so the number may yet improve.


2013 2014 2015 2016 2017 2018 2019 2020
GBB Gull nests - 62 37 83 70 60 71 (59)
GBB Gull eggs/chicks 98 174 90 204 166 - 195 (146)
GBB Gull chicks ringed 4 17 12 13 5 3 16 14

For the first time we also saw not one but two of our own ringed birds on the island, of an age now where they're probably breeding. It was good to see the rings on these birds were still looking good, as in some cases they can wear quite rapidly, making them hard to read. See below examples from Looe Island (taken two days ago) of worn rings from 2010 and 2011.

LDA2 was ringed as a chick in 2015 and has been seen several times at Southerly Point, Lizard
and once at Coverack. It was last reported in November 2018.

With a remarkably similar history, LBH7 was ringed as a chick in 2014 and is also a frequent visitor to
Southerly Point, has also visited Coverack once and was last reported in September 2018.

Not all ring wear is even though, as the photos above and below are actually different sides of the same ring (L:AL8)


Strangely there were still also one or two Cormorant chicks in the nest which is very late, but most were long gone, leaving just their mallow-stick nests as evidence.


A sorry reminder of the times we're now living in

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