The wind has swung round to the South East, the seas have become rough and we’re all enjoying the cooling breeze that blows across the island most days. That’s right, its officially the time of the South-East Trade Winds, and together with relief from the heat of April, that means the seabirds are back, including the extremely vocal wedge-tailed shearwaters.
Here on Cousine, the lesser noddys have finished nest building. Most have laid eggs and in fact this week the first chicks were spotted during our weekly nest monitoring. A total of 150 nests (divided into 15 different ‘plots’ of ten nests) have been chosen around the island; each week, armed with binoculars and a nifty mirror-on-a-pole, two of our team make the rounds and record how each nest is getting on. Because the chicks are still small, it’s still tricky to figure out what the adults are sitting on – egg or a ball of fluff! Monitoring these nests will allow us to calculate the breeding success rate of the lesser noddys nesting on Cousine Island, and to identify which stage eggs or chicks are failing at. Many of the brown noddys, which nest in coconut trees and on rocks on the ridge, also now have chicks.
Since the last edition of Wildlife News, we have re-established our White-tailed tropicbird nest monitoring which will run year-round as their breeding is not restricted to the South-East Trade Winds. This year the methodology has changed a little, in line with methodology used on other islands including Aldabra Atoll; rather than checking a fixed number of nests, we are now monitoring fixed demarcated areas. This allows us to detect changes not only in success rates but also in the density and number of nests, across the different seasons and years.
At the beginning of June, we had the pleasure of welcoming Dr Mark Brown from Nature’s Valley Trust to the island. The purpose of his visit was to train the conservation staff in bird ringing. A very fun two weeks was spent catching, measuring and ringing a total of 835 birds of many different species – from tiny sunbirds, warblers and fodys, to much bigger tropicbirds, shearwaters and sooty terns. We even managed to catch some of our Seychelles magpie robins, including a new fledgling and the only un-ringed adult on the island. Becky, James, Chloe and Paul are now all licensed bird ringers with the South African Bird Ringing Unit (SAFRING). This will really open up the research and monitoring possibilities for the island; we can now ring the tropicbirds whose nests we monitor weekly, and gain valuable information about breeding cycles and site fidelity.
And last but not least, a quick update on our annual seabird census carried out each year in the first two weeks of July. At the end of the first week, we have counted lesser noddys, brown noddys, fairy terns and white-tailed tropicbirds in 31 out of our 48 plots around the island. By the end of next week, we will have an estimation of how many pairs of each species we have breeding on the island but so far, the numbers are looking good.
Original content source: Cousine Island
Original authors: James McClelland and Becky Hodgkiss
Original image: Cousien Island