News in brief from Aride, Bird, Cousine and Fregate in the second half of 2005.
Aride Island by Frankie Hobro
The south-east monsoon season (April to October) has proved to be far wetter than in previous years, so no drought this year.
The seabird breeding season continued with relatively high breeding success. The Roseate Terns disappeared as suddenly as they arrived, with the majority of birds gone by the end of August. By this time, the first of the Sooty Tern chicks and many of the Brown Noddy juveniles were starting to stretch their wings.
As the end of the seabird nesting season approached, the Wedge-tailed Shearwater breeding season began. Many adults were seen by day on the hillside from August onwards, starting incubation in their selected burrows. Audubon’s Shearwaters are also plentiful as ever. The Frigate Bird population as usual showed a distinct increase as the north-west monsoon season approached, with numbers increasing from 300 in July to over 2,000 at the end of September.
Many fledgling Seychelles Warblers and Seychelles Fodies have been seen, and several Blue Pigeon nests have produced fledglings. The Magpie-robin population increased further in September to 17 birds, with another fledgling. With more eggs under incubation, the population looks likely to increase further still.
There have been several unusual bird observations, as well as regular sightings of Red-Tailed Tropicbirds. A Eurasian Curlew was with us for a while. One-off sightings included four Great-crested Terns, an immature Grey Plover, a Yellow Bittern, an immature Masked Booby, a Cattle Egret and a Green-Backed Heron. The most memorable and impressive sighting was an adult Sperm Whale, seen in September, around 1km off Booby Rock.
September brought the first of the nesting Hawksbill Turtles. By mid-October there were more than six nests, a lot for this early in the season on Aride. We opened the new Island Conservation Centre in October. This and its laboratory should prove immensely beneficial to education groups, visiting tourists and researchers.
Bird Island
The Sooty Tern breeding season has proved to be a good one after all. It had started off quite slowly, with all sorts of odd things happening earlier in the year, such as some eggs being laid as early as February, at the end of the runway. Searches were carried out for birds with leg rings, as part of the continuing programme co-ordinated by Chris Feare, who has been involved with the colony since 1972. At this time, the colony numbered around 100,000 pairs. This was an increase on the 18,000 pairs restricted to the northern end of the island in the late 1960s. Thanks to habitation management, the current population estimates are in the region of 750,000 pairs nesting over approximately 15 hectares.
In total, 313 ringed birds were found. Two birds that had been ringed as chicks in 1972, Chris’s first year of ringing, were found, and 15 that were ringed in 1973, making these birds 33 and 32 years old. Strictly controlled egg collecting is helping to keep the equilibrium between the expanding Sooty Tern colony and other resident seabirds on the island. Since 1996, when Bird was the first island to successfully eradicate rats, the numbers of ground-nesting Brown Noddies, White-tailed Tropicbirds and Wedge-tailed Shearwaters have increased tremendously.
With the help of Nature Seychelles it is planned to introduce the endemic Sunbird (right) to the island, both for its aesthetic value and for its value as a pollinator, thus increasing ecosystem diversity and complexity. Nature Seychelles staff have studied the habitat and are confident that it is suitable. The plan is to take around 40 birds from Mahé and release them on the island. The Mahé population is very large and the capture of this quantity of birds will have no effect on the existing population. It is planned to make the translocation outside the main breeding season in a period of higher rainfall.
Cousine Island by James Lawrence
On returning to Cousine after two years, to help out with start of the Hawksbill Turtle breeding season, I have noticed that the island has thrived. The trees that were planted on the coastal plateau are growing well and are starting to form a dense forest, creating new habitats for the island’s fauna. Also, for the first time in approximately 40 years, Sooty Terns have returned to breed. This is a major milestone given that the species was, until very recently, found on only a single managed island in the region.
The Hawksbill Turtle season started at a slow pace, with only three nests being laid at the time of writing (late October). The island even has a young Hawksbill Turtle resident off the North Beach. It is seen almost daily and was even observed being careless, resulting in it being dumped on the beach by a wave! Lily, our youngest Giant Tortoise, has settled in very well and has already doubled in weight since her arrival in February this year.
The Lesser Noddies finished off their main South-east monsoon breeding season with fledglings all over the island. Unfortunately this period coincided with a heavy fruiting of Pisonia grandis, the seeds of which have stuck to many birds, including Tropicbirds. An adult Masked Booby has been seen flying over the island. The Blue Pigeon population has also apparently increased, with several nests found. A full census of Cousine’s land birds is planned.
Night-time monitoring of the Seychelles Giant Millipede has been conducted. Numbers have increased quite dramatically since the last census. It’s good to see the numbers increasing, given the importance of the Millipede in leaf litter breakdown, nutrient recycling and soil formation on the island.
Finally, we have welcomed Dylan Evans and Frankie Hobro to Cousine as the island ecologists. We wish them a happy and productive stay.
Fregate Island by Rahel Winiger
Rahel volunteered her services to Nature Seychelles. As part of her duties she spent one week on the exclusive, private island of Fregate, from which she filed this short report.
My job as a volunteer on Fregate at the start of September was to carry out a census of seabirds, the first survey of its kind on the island. Frankie Hobro from Aride Island was my partner. We had to cover 5% of the whole island to get a representative result. We did systematic plots, every 120 metres, with the help of a tape measure, a compass, and a map.
In each plot we had to count the Lesser Noddies, Fairy Terns, White-tailed Tropicbirds and Blue Pigeons. In addition, we wrote down the various species and the percentage of vegetation. Out of this information the population and the favourite places of the birds can be seen, which may help us to establish birds on other islands of Seychelles.
Most of the birds were counted in the east, for example near the canteen, in the former coconut plantation and the forest of dead Sandragon trees (killed like most in Seychelles by a fungal disease), whereas on the west side of the island seabirds were not often seen.