Nature Watch

I am just back from a visit to the island and have a lot of topics to cover so hopefully, other work permitting, I will be able to make up for the dearth of posts over the last week or so. It is the rainy season at the moment in the central archipelago and we have been having a lot of precipitation on Mahe over the last few weeks. Denis however being small, isolated and flat does not get as much rain as the mountainous granite islands – but on approaching the island on Thursday it was clear that there had been rain as the island was a lush green colour. Indeed as we landed the clouds opened again and it rained steadily for a couple of hours that afternoon. After that however the weather cleared and was fare for the next couple of days enabling me to get around and catch up on developments.

There has been considerable sand movement since my last visit with the distinct sand promontory known as “Pte Madame Guichard” having now reformed and reaching some 50 metres out off the west coast of the island.

As I mentioned the vegetation on the island has benefitted from the rain but Belle Etoile (the cattle meadow on the east coast) has been transformed. A couple of months back I noted how it was brown and all the vegetation had died back revealing the actual lie of the land. Well the grass is once more knee high and upwards, the tortoise tree coppices are in full leaf and many of the saplings planted for coastal rehabilitation which were looking doubtful last year are showing signs of new vigour!

Moving further south I went to check on the tropicbird chick “T2” ground nest to find the bird has fledged. On checking with island staff I was advised it had successfully fledged the week before – so that now makes two successful fledglings from 3 ground nests – a most encouraging start!

Continuing south to the southern point I emerged on the beach to see a heron perched on the southern rocks. It’s unusual to see herons on the island and the light was very bright in effect silhouetting the bird such that I couldn’t really determine its plumage colour. I took a few photos from a distance in the hope that I may be able to discern more detail once they were transferred to the computer screen and then slowly made my way forward. The heron was however vary wary of my presence and before I could move any significant distance closer it took flight eastwards before arcing north and west out of sight up the coast. I was still not sure of its species and so decided to pursue it assuming it would head for the rock promontory on the east coast at Belle Etoile which would provide it with a safe perch surrounded as it is on three sides by the sea.

However as I turned to head back my eye was a caught by a familiar silhouette perched at the top of a casuarina sapling – it was a Bee eater. There are a few still on the island from the mass invasion we experienced in November (See post of 29th November 2008) and Catherina has subsequently told me that the island received another influx of 20 or so birds at the beginning of the month. I took a few shots of it before heading north up the coast in pursuit of the heron. I followed the coast initially but as I reached the Belle Etoile meadows I cut back in land so as to obscure my approach with the vegetation. When I got there however, I was disappointed to find the bird was not where I had anticipated and thinking it had likely flown further north decided to resume my previous path. As I turned to head south once more I saw it, its head bobbing up from behind a sandstone outcrop further south – it was observing me not vice versa!!!

Clearly this bird was very wary and knew of my presence so I cut back in land and tried to approach through some thicker vegetation. Again the bird was smarter than me and was looking directly at me when I emerged from my supposedly hidden route! I took a few more photos from some considerable distance and then accepting defeat left the bird in peace.

On getting back to Mahe I have looked carefully at the photos and magnified them using the usual software. It is a grey heron (Ardea cinerea) it looks like a sub-adult with not all the adult plumage developed; with for example only the beginnings of the black plumes on its head and its legs still a grey colour. This is my first record of a grey heron on Denis, though I am sure they must visit from time to time, but interestingly the timidity of this bird distinguishes it from the very bold birds found on Mahe and suggests that it is just passing through and normally frequents more tranquil parts or alternatively a place where it has reason to fear man.