In 2018, the Roseate Tern LIFE Recovery Project team set about installing a new raft at Port Edgar. RSPB Scotland’s Chantal Macleod-Nolan fills us in on the project.
Port Edgar Tern Raft Success
From the early 1990s a tern raft was in place at Port Edgar in Scotland. It wasn’t regularly monitored, but the records that exist show that there was a yearly average of 6.2 Apparently Occupied Nests (AONs), with a record high of 20 recorded one year. Unfortunately, storm damage was so extensive in 2014/15 that the raft had to be removed.
In 2018, the EU funded Roseate Tern LIFE Recovery Project installed a new raft in the hope it would support the local common tern colony at Long Craig island, where roseate terns had also historically nested. As the island has low lying profile, it is prone to getting inundated and the raft was seen to be a suitable alternative nesting site for the common tern population should they need it.
Common terns nesting on the raft in 2019 (c) Chris Knowles
2019 a great year for the raft
Throughout the 2019 breeding season the raft was monitored on average every four days. From the western harbour wall, visibility onto most of the raft is very good with a spotting scope and binoculars. The team was delighted to record 118 chicks fledgling from 109 apparently occupied nests. It should be noted, that the count will be lower than actual numbers as it is not possible to count all eggs or chicks due to some restricted views.
Maintaining the raft
The raft was brought in and moored against a jetty over-winter to protect it from the strongest tides. Before returning it to its breeding season location in 2020 a number of improvements and maintenance work was carried out. A team comprising of members of the Forth Seabird Group, local RSPB staff and the Roseate Tern LIFE project crushed the existing shell into smaller pieces as well as adding coarse sand. Anti-predator canes were added to deter gulls from colonising the raft before the terns, and from predating eggs and chicks later on. The barrier to stop pre-fledged chicks from going overboard was also raised with a mesh encircling the raft. The Port Edgar staff then added a navigational marker and buoys to the structure to make sure the raft is up-to-date with all required specifications.
Maintenance on the raft prior to 2019 breeding season (c) Chris Knowles
Luckily the team had already put the raft out before Covid-19 restrictions were introduced. So, while it hasn’t been possible to do any touch ups, such as sorting out decoys, reapplying shingle or recording this year so far, it will be interesting to see if the terns use it again.