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Kittiwakes: A challenging year

posted 15 Jul 2013, 12:38 by Philip Collins   [ updated 2 Oct 2013, 08:57 ]
Kittiwake with a chick

With the Razorbill and Guillemot chicks currently in the midst of fledging, our attention on the island has now turned to the kittiwakes. As I have mentioned before, the kittiwakes are quite late this year with some birds still on eggs (whether or not these will hatch remains to be seen), while others are with small chicks. In addition to the birds still active in their breeding efforts, there are the birds which have failed to lay, or have laid eggs which have subsequently failed. Unfortunately these birds make up a large proportion of the kittiwakes currently on Puffin Island, with productivity looking to be very low this year.

Kittiwakes are widely regarded as sensitive indicators of environmental conditions, and low productivity following the coldest spring in 50 years is not altogether surprising. It is interesting to note however that the razorbills and guillemots seem to be having a good year, thus highlighting the variability in how different species respond to environmental conditions. 



Kittiwake colony - Although birds are still occupying their nests, the majority have failed and are empty.

All is not doom and gloom however, as we have proceeded with accelerometer and GPS deployments on kittiwakes in our study sites which are still active in their breeding efforts.  These two types of devices should provide us with a wealth of information. Accelerometers measure movement of the birds at a very fine temporal scale. This means that behaviours of the birds can be identified throughout the duration of the logger deployment, including when at sea. Through this data, we can start looking at time allocated to certain tasks (foraging, nest attendance, resting at sea etc) and the potential energetic implications associated with these tasks. These devices, as with GPS devices, sit on the back of the bird, as shown in the picture below.

 

Accelerometer attached to Kittiwake

As mentioned in previous posts, the GPS devices we deploy provide accurate information of where the birds have been throughout the time they have been equipped with the loggers. An example of one of this year’s GPS tracks is shown below. Interestingly, this track shows quite localised foraging, indicating that there’s enough prey in the local area to prevent the need for longer foraging trips.

 

An example GPS track from one of this year's kittiwakes

The poor breeding success of the kittiwakes this year has certainly made our research more challenging, however it does also offer the opportunity to monitor what happens when things don’t go well. Such information is definitely of value.

 Moving away from the kittiwake work, the SCAN ringing group have completed two out of three of their annual ringing trips to the island. The group make yearly trips out to the island to ring Razorbill, Guillemot, Shag, Cormorant, Kittiwake and large gull chicks, along with a few adult birds. The two trips which have taken place to date were a great success with large numbers of birds having been ringed. Such projects are incredibly valuable in furthering our understanding of bird population dynamics and movements, and given that ringing on the island has been taking place over a timescale of decades, the Puffin Island site is particularly important.

It is also the case that when the opportunity arises to ring something a bit less widespread on the island it is taken. We managed to find this Oystercatcher chick while carrying out some other work, and needless to say it wasn't long before it was sporting a ring on its leg.  

Freshly ringed Oystercatcher chick

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