Tuesday, 16 August 2016

The end of another season

The breeding season at the Long Nanny tern site has drawn to a close. The majority of the birds have left, starting the migration to their wintering grounds. The site is packed up, tents collapsed and the assistant rangers that vigilantly watched the colony throughout the summer have moved on to other things.
Little terns and Arctic terns nesting on the Long Nanny spit © Kate Bradshaw
It hasn't been an easy season, but five little tern Sternula albifrons chicks fledged from a minimum of seventeen nesting pairs. There were thirty seven nesting attempts made through out the season, but some of these may have been repeat attempts by pairs that lost nests earlier in the season. It is therefore impossible to say exactly how many pairs nested on site. The nesting success of the little terns was impacted by stoat, kestrel and poor weather mainly during the incubation period. 

Although the number of fledglings seems low we managed to avoid any losses due to flooding of nests at exceptionally high tides in June and July. This is through ranger intervention during the events and the raising of nests onto fishing crates to reduce the impact of tides. Some of the little tern colony nested in a new area of the site this year. This provided them with slightly more protection against high tides compared to the exposed area of spit that they have historically nested on. This meant that three nests did not need to be raised onto fishing crates at all this year.

Little tern nests raised onto fishing crates and pallets © Kevin Redgrave
Around a thousand pairs of Arctic tern Sterna paradisaea bred on site this year, which is almost half of last years breeding population. Sadly they experienced a very difficult season, with only two chicks known to have fledged.  Their nests were impacted by the extreme high tides and productivity was affected by poor weather, predation and possibly poor feeding when chicks were hatching.

Ringed plover Charadrius hiaticulaalso also breed at the Long Nanny and are often forgotten in the hubbub of the tern colony. This year five chicks were successfully fledged from sixteen known nesting attempts by a minimum of six pairs.
Ringed Plover
A variety of predators were a problem this year with stoat and kestrel causing the most problems. Earlier in the season we also struggled with crows and gulls, particularly black-headed raiding the site. However the vigilance of the five rangers and volunteers protected the little tern colony from the majority of predator attacks until site closure on 27th July.

Many thanks to this years’ assistant rangers  - Alan, Rachelle, Oliver, Scarlett and Will, all the volunteers that worked throughout the season and to everyone who cooperated with them to help make the breeding season as successful as possible.

Sunset at the Long Nanny ©Rachelle Regan

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