Preston Dock Common Terns
Update
If you have visited Preston Dock recently, to observe the Common Terns nesting, you will have noticed canes sticking out of many of the nest trays. As we have had a number of queries about the canes, with some perceiving that the canes are in some way detrimental to the bird’s ability to nest, we have provided an explanation on the purpose of the canes. The dock is managed by Preston City Council. The Fylde Bird Club have been advising the Council on the Common Tern colony and have provided nest trays and other materials. The Fylde Bird Club also monitors and records the progress and productivity of the Tern colony.
The canes are fitted to the nest trays to deter Lesser Black-backed Gulls, which have become skilled at snatching Tern chicks from their nests, resulting in unsustainably high losses.
The gulls swoop down at speed and grab chicks while in mid-flight. The canes are intended to provide obstacles to prevent this form of attack.
Our experience, from closely monitoring nest box use last year, proved that the Terns had no preference for boxes in sets with or without canes. We counted all the occupied trays in sets with and without canes on every visit and this was established beyond doubt. Given the very high losses to Lesser Black-backed Gull predation, we agreed to fit canes to all sets of trays this year from the start. Productivity has been unsustainably low for several years and so doing nothing was not an option we considered. Last year coot predation of eggs and bad weather may have been as significant but only 3 young fledged.
Canes are used at other Tern colonies with great success, so this is not a new experiment. They have been introduced after consultation with the RSPB.
We will monitor progress again this year and respond to the findings accordingly, so far as we are able. All counts and details of Terns nesting at the dock are most welcome. We would like to install an anti-Coot fence around the breakers but this year Covid prevented any progress. We need a practical design that the Council will accept; previous suggestions were rejected.
The canes are fitted to the nest trays to deter Lesser Black-backed Gulls, which have become skilled at snatching Tern chicks from their nests, resulting in unsustainably high losses.
The gulls swoop down at speed and grab chicks while in mid-flight. The canes are intended to provide obstacles to prevent this form of attack.
Our experience, from closely monitoring nest box use last year, proved that the Terns had no preference for boxes in sets with or without canes. We counted all the occupied trays in sets with and without canes on every visit and this was established beyond doubt. Given the very high losses to Lesser Black-backed Gull predation, we agreed to fit canes to all sets of trays this year from the start. Productivity has been unsustainably low for several years and so doing nothing was not an option we considered. Last year coot predation of eggs and bad weather may have been as significant but only 3 young fledged.
Canes are used at other Tern colonies with great success, so this is not a new experiment. They have been introduced after consultation with the RSPB.
We will monitor progress again this year and respond to the findings accordingly, so far as we are able. All counts and details of Terns nesting at the dock are most welcome. We would like to install an anti-Coot fence around the breakers but this year Covid prevented any progress. We need a practical design that the Council will accept; previous suggestions were rejected.
History
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In 2009 a pair of Common Terns made a nesting attempt on a wave breaker at Preston Dock, successfully raising two young, the first such breeding at the site. The Fylde Bird Club decided to try and capitalise on this initial breeding attempt, seeking to create a thriving tern colony by introducing artificial tern nest sites on the wave breakers at Preston Dock. In April 2010 Paul Ellis and Paul Slade installed a number of gravel-filled tyres and slate shelters on the wave breakers in the hope of enticing terns to breed. The project proved to be a huge success; in 2011 ten pairs nested and by 2012 a colony of approximately 30 pairs had established. In subsequent years further tyres and special nesting trays were installed which increased the capacity for the burgeoning colony.
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Since that initial breeding attempt all six regularly occuring British tern species have been observed at Preston Dock:
Common Tern - The first adult birds arrive back at the colony in the last week of April and first week of May, with numbers quickly building from there. In 2013 totals there were over 100 attempting breeding pairs in the colony, producing at least 70 young. The deployment of new rubbber tyres and nesting boxes in 2014 saw the colony swell again to 140 pairs with a high chick count of 104 in early July. 2015 again saw 140 pairs attempting to nest however there was a low success rate due to a pair of nesting Coot on the pontoons that predated a large number of tern eggs. In 2016 more detailed observations of the colony revealed at least 138 pairs of Common Tern attempting to nest, rearing at least 64 young successfully. Unfortunately whilst the number of pairs has remained in three figures in both the 2017 and 2018 seasons, extremely high predation levels by just one or two Lesser Black-backed Gulls has resulted in an almost total nest failure, with only a handful of chicks successfully fledging in each year. Several ringed adults have appeared at the site from other north-west colonies, whilst one returning adult had been ringed on it's wintering grounds in Namibia!
Arctic Tern - During the 2012 season up to 2 adult Arctic Terns appeared within the Common Tern colony on several dates, although they showed no interest in breeding. This changed in 2013 when a pair laid a single egg which subsequently failed, with the first successful breeding occuring in 2014 with at least 3 pairs attemtping to breed, 2 of which hatched single chicks with 1 going on to fledge. In both 2015 and 2016 up to 4 pairs attempted to breed but although some reached the egg stage none were successful. 2017 and 2018 have seen up to 5 pairs present within the colony throughout the summer, with single chicks fledging in both years despite the predation pressures.
Black Tern - In 2016 a strong spring passage along the Fylde coast resulted in a peak of 15 birds in the dock in mid-May. Short-staying adults have subsequently been recorded in May and June 2017, and May and July 2018, mostly being found in the evenings before going on to roost on the pontoons.
Roseate Tern - A real Fylde rarity, 2 adults were observed in the colony for a short time on the morning of the 30th July 2014, and another adult made two brief appearences on the pontoons on the 8th-9th July 2018. It is hoped the continuation of the colony will result in more records of this species in the future.
Little Tern - A near-adult bird made a brief visit to the colony on the morning of the 8th July 2018.
Sandwich Tern - The single record from the dock comes from the 17th May 2013 and probably relates to a bird driven up the Ribble by strong winds.
Fylde Bird Club would like to offer special thanks to Andrew Newsham from Preston City Council for setting out the nest materials and to the RSPB for their help and advice with the project.
