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Read by Dave and Charley
With Durrel and half-term in between the answers to the questions for our food chains and life cycles topic have been long awaited. Way back on the 19th May I first posted some questions on these topics and reminded everyone of them this past Monday. Here are the questions again for you all:
- What is a puffins favourite prey?
- Lesser black-backed gulls do not eat puffins, so why do they chase them?
- Which land predators of seabirds does Alderney have, and which does it not have?
- Why do seabirds migrate?
- How much longer do fulmars incubate compared to ringed plovers?
- How much longer do gannet chicks take to fledge compared to shags?
- If a lesser black-backed gull hatches on the 11th June, when will it fledge?
The answer to the first two questions were correctly provided by Afua from Gateway Primary.
Well done to Afua for being the first to find out that puffins prefer to eat sandeels whilst lesser black-backed gulls chase puffins to steal their fish in an action known as kleptoparasitism. Congratulations to Finn W and the Haydn Primary pupils who also found the answers.
For our other two questions we can see that Alderney has rats and feral cats, but does not have foxes or badgers; and seabirds migrate to areas where they are more comfortable and food sources are richer.
The maths questions can all be answered by referring to our nesting, hatching and fledging table.
- Fulmars incubate for 52-53 days compared to ringed plovers at just 23-25 days. This is 27-30 days longer.
- Gannet chicks take 84-97 days to fledge. This is 26-49 days longer than shags that take 48-58 days to fledge.
- If a lesser black-backed gull hatches on the 11th June, it will fledge between the 11th and 21st July.
One of our recent Burhou trips was to try and catch some shags and attach GPS tags to them. This was being done by Vicky as part of her PhD studying shags and gannets (details on the gannet tagging will come next Wednesday). Unfortunately shags are very flighty birds and hard to approach meaning that we could only catch one on Little Burhou and none on Burhou.
Ecology is a field of work where things often don't go to plan as predicting nature is incredibly difficult. But we always adapt to the situation and hopefully the tags that we have for shags can be put to use on other colonies on other species' in the near future. If they are we will be sure to let you know.
Back on the 21st of May I told you about counting the shag population of Alderney. Well, on the 14th June I went to Coque Lihou with Vicky and Phil Atkinson (British Trust of Ornithology) to finish the count of shag nests. This year there were 66 nests! Whilst this is lower than the 77 we had on Coque Lihou last year it is still a lot and confirms we have a total population around Alderney and its islets of 165 pairs of shags! Almost as many as our puffins.
What was even better though was that the chicks on Coque Lihou were large enough for us to ring. So Vicky and I, under the guidence of Phil, ringed all the chicks on nests that were large enough to take the ring on its leg.
By ringing birds when they are chicks we know where they were born when they are sighted again later in their life. It is a very exciting part of our work to learn more about the migration and foraging habits of our seabirds; it is also a privelege to be able to get so close to the birds.