Tuesday 4 August 2015

Juveniles (but no delinquents!)

We have already looked at other species breeding inside the Tern colony - Oystercatcher, Ringed Plover, Skylark and Mallard. We have also seen other avian life outside the colony fences. Naturally, many of these species are breeding as well, and it is not just Little Terns that are fledging at Kilcoole. A long and very genteel ringing session last Sunday (I estimate we boiled the kettle for tea and biscuits at least 10 times) threw up plenty of juvenile passerines. These species nested within the Buckthorn at the north end of the colony or in the surrounding NPWS reserve and farmland.

A Sedge Warbler has his measurements taken during Sunday's ringing session (photo: Paddy Manley)

Among others, we had juvenile Willow Warbler, Sedge Warbler, Starling and Reed Bunting. Over the course of the season, there has also been evidence of breeding Blackbird, Yellowhammer, Dunnock, Great Tit, Blue Tit, Stonechat, Linnet, Goldfinch and Robin. Inside the lagoon, we have breeding Coot and, of course, the Mute Swan pair with their cygnet. Juvenile Kingfisher have been spotted in the channel.

Juvenile Sedge Warbler (photo: Paddy Manley)

Juvenile Willow Warbler - much yellower than adults (photo Paddy Manley)

Susan in conversation with a young Willow Warbler

Only in the past few weeks did I begin to see the juvenile flocks out and about. Murmurations of between 100 and 200 juvenile Starlings rise up out of the farmland on foraging trips. A small flock of perhaps 10 juvenile Linnet forage along the railway line, while a family group of Skylark regularly feed on Hogweed seeds in the camp.

And of course there are the non-birdy breeders - I have seen fox cubs and a baby hedgehog. Kilcoole also has a resident family of otters, and plenty of rabbits. The sand dune plants also support a great number of butterflies, with Meadow Browns in particular out and about on calm days.

The juvenile Terns are still at the colony: approximately 70 are loafing on the tideline today. I had a great insight into Tern communication between adults and their young when a Peregrine Falcon flew over the colony this morning. The adults and older chicks instantly took off out to sea when the Peregrine swooped over. The younger chicks flattened themselves into crouch-defense-camoflage position among the shingle on the foreshore. They remained perfectly still and crouched while the adult flock was out to sea avoiding the preying Peregrine eyes. As the flock returned to the shore again, I began to hear their chattering calls. Evidently the chicks heard it too and knew that it was safe, because they began to stand up and stretch out their wings and legs. One chick suddenly cheeped wildly and fluttered his wings in excitement and a few seconds later, his parent landed with a sprat. However, during his excitement, all the other chicks remained perfectly placid, indicating he knew that food was arriving for him, and him alone. These observations indicate that the chicks can differentiate calls for "hide, there is danger", "everything is alright" and "where are you? I've got dinner!". They also know the individual "voice" of their parents.

Like the young passerines we caught on Sunday, soon the last of these Little Terns will be experienced enough to  become more independent of their parents and strong enough to make the great journey south.

Susan and Paddy

2 comments:

  1. Nice piece of observation on the tern communications. Do you think that the adults can identify their chick by its voice or appearance or both? Richard

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    1. It is predominantly voice - each bird has its own unique call that others can recognise it by. This is also the case in a lot of other bird species.

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