ISLAND CONSERVATION SOCIETY-Black-naped terns breed on St Francois Atoll: Fact or Fiction? |10 March 2008
This species is fairly common around St. François all year round, however this time something was different. Approaching closer he realised that they were displaying territorial behaviour. Strongly suspecting that they were breeding, he went up onto the sand bar to take a closer look. Indeed, several pairs of Black-naped terns were present, and on closer inspection he managed to see one adult sitting on an egg. He quickly reached for his camera to capture this exciting moment but kept his distance so as not to disturb the other birds in the colony. After a hard day’s work on St. Francois reef flats, Wayne was looking forward to getting back to Alphonse to tell ICS guys about his discovery.
As part of the ICS staff on Alphonse I have been eager to confirm St. François Atoll as a breeding site for Black-naped terns but unfortunately we have never had the opportunity to do so until now. Previously, in July 2007 we had only managed to site recently fledged chicks which indicated that they must be breeding somewhere close by, but the question was where? It was believed that they were nesting on some of the ship wrecks that are lodged into the southern part of St. François Atoll reef but unfortunately access to the wreckage to verify this theory was too dangerous.
Wayne’s discovery was too good to be true and we had to see for ourselves. So Aubrey Rose and I didn’t waste any time and as soon as the weather improved we shot out to St. François at 7 a.m. on February 3. Since we had a lot of ground to cover and did not know the exact location of the nesting terns, we decided to split up. I went along the outer edge of St. François Island to conduct turtle monitoring whilst Aubrey walked across the reef flats to the large sand bar that we presumed Wayne was talking about. To his amazement, Aubrey counted ten active nests (c.10 pairs) concentrated in a small coral rubble patch at the northern end of the sand bar. Six of the ten nests had a single egg each and 4 of them had two eggs each. The eggs are greenish blue with dark speckles 
Aubrey was not the only one to have all the fun; I was to make my own discovery: fairly recently (2007) a sand bar has been created on the western side of St. Francois (opposite Pointe La Courte) and is slowly being colonised by young casuarina trees (Casuarina equisetifolia), coconuts (Cocos nucifera), vouloutye (Scaevola sericea) & bwa matlo (Suriana maritima). However, it still has some areas which are fairly open and to my surprise I spotted one nest with two eggs amongst the small coral rubble pieces. This discovery increased the total number of active nests to eleven (c.11 pairs). It will be interesting to see whether more terns decide to breed on this new sand bar, and also whether this single nest is successful. ICS will be monitoring the nesting sites closely in the coming weeks to document their progress.
Black-naped terns do not commonly breed in Seychelles, but are known to nest on the ground of small predator-free islands during various times of the year. Currently they breed on Aldabra (c.50-70 pairs), African banks (c.10 pairs), St. Joseph Atoll, Cosmoledo (c.50 pairs), Farquhar (over 40 pairs) and Bancs Providence (A. Skerrett, I. Bullock & T. Disley, 2001).
Now St. François Atoll can be added to the list, although more information with regards to the number of breeding pairs and duration of the breeding period needs to be gathered. This is a positive discovery for a seabird population that is poorly distributed and fairly restricted in the Seychelles due to the presence of rats and cats on many islands, with a population of not more than a few hundred pairs only for the whole western Indian Ocean.
Pierre-Andre Adam
Alphonse Island Conservation Centre