Friday 20 November 2015

Conservation updates from Denis Island

Seychelles Warbler
The Denis Island conservation team together with the Green Islands Foundation (GIF) volunteers and University students, has been very busy on the island with the Seychelles Warbler data collection, the vagrant season and the Hawksbill turtle nesting season. Here is a summary of what they've been up to over the last two months.







Seychelles Warbler Students

Seychelles Warbler nest with egg and chick
This month, the two students Leticia and Stephanie (affiliated with the Seychelles Warbler group / University of Groningen), left Denis Island after three months of field work and data collection on the Seychelles warbler. The Seychelles warbler is one of the four endemic bird species that have been introduced to Denis Island to (further) save them from extinction. You can often hear the melodic calls of this small song bird around Denis. Their project encompassed population monitoring of the species on Denis, through mist netting and banding, along with nest observations. Not to mention, valiantly thwarting the mosquitoes found in the deep forest! The students also took blood samples from the warblers that were caught, and transported said DNA and plasma samples back to the Netherlands to undergo analysis in the lab. Since the birds were first translocated to Denis in 2004, the population of the warbler on Denis has been regularly monitored.

Warbler student with Leticia


The students found that the population has overall increased compared to the previous years, and they have estimated that it has now reached approximately 400 warblers. The two current GIF volunteers from Canada, Jodi and Chelsea, assisted the warbler students in the field, and gained important field experience regarding ornithology. The warbler students mentioned how much they enjoyed their stay on Denis and the unforgettable memories they made while on the island. The work the students did on Denis is very much appreciated and helps to further the conservation efforts the island takes prides in.





Birder's alert: vagrant season is starting!

Collared pratincole
Vagrant season is upon us here on Denis! This is an exciting time of the year, as species of migratory birds that are normally rarely seen in the Seychelles decide to grace us with a short visit. A bird is considered a vagrant when it strays outside its expected breeding, wintering or migrating range. This tends to really kick-off in the beginning of October, as birds are migrating to warmer climates for the winter. As Denis among the northernmost islands of Seychelles, it is probably the first land that the birds encounter after a long stretch of sea, and birds take the opportunity to rest and re-fuel for the reminder of the journey. 


European roller
Quite some interesting bird species have already been spotted on the island just these past few weeks! Such species include the European roller, collared pratincole, little stint, sand martin and the common redstart. The Little Stint hails all the way from Arctic Europe and Asia! Once these birds have been spotted on Denis, pictures are taken and a form is filled out, which is then sent to SBRC (Seychelles Bird Records Committee – Adrian Skerrett) and included in a nation-wide report. Birders who are interested in laying eyes on one of these special visitors, best make their way to the airstrip. They tend to flock towards this open area and are often found on the ground or in the trees along the length of the runway.

Start of the Hawksbill turtle nesting season

Hawksbill turtle on beach
The change of the South East season into the North West monsoon means the onset of the hawksbill turtle breeding season on Denis Island. Unlike the green turtles that nest at night, the hawksbills nest during the day around high tide. For the guests of the resort this can result in an unexpected and unforgettable encounter during a stroll on the beach! When nesting, the hawksbill turtle comes up the beach and lays about 150 eggs, which hatch after approximately 60 days of incubation. The temperature of the eggs determines whether males or females are being born. The way down to the sea is one full of danger; particularly the ghost crabs do seem to like a little turtle snack! Once the hatchlings reach the sea, it is estimated that they will take 25 years to reach adulthood. The best chance to encounter little turtles crawling down the beach is when the sun is less hot, so around sunrise or sunset. 


Hawksbill turtle eggs
The Denis Island Environment team conduct one or two turtle patrols every day, to count the number of tracks of nesting turtles and to tag any turtles that they encounter. For this they walk the 5 km-long beach surrounding the island, which takes ca. 2 hours. A good exercise! The monitoring they do forms part of the nation-wide turtle monitoring programme, and gives a better insight in numbers of nesting turtles, their seasonal nesting patterns and distribution and migration between islands and abroad.

Warbler students and volunteers

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