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Wednesday, March 25, 2009

Denis Island contributes to knowledge on migratory birds…

Over the preceding few months I have periodically posted on our observations of migratory birds. Denis’ position on the north of the Mahe plateau makes it a very interesting location for migratory birds as for many it may represent their first landfall in some 1000 miles of flying over the Indian Ocean! This strategic position makes the island a magnet for exhausted or storm blown birds. Despite this bird records from Denis are rather sparse simply because there have rarely been ornithologists on the island for any extended period. Over the last year or so however the combined activities of various researchers visiting for different projects, the presence of Catherina, my periodic visits and the interest of an island resident have allowed us to start building up a generalised picture of what birds are visiting the island or actually overwintering on the island.

We are not yet undertaking any standardised monitoring as we lack sufficient personnel to do this, so observations are purely ad-hoc or opportunistic nevertheless they are not without value. The Seychelles Bird Record Committee (SBRC – you can connect to their site via the link in the sidebar of this blog) is the agency that compiles records of birds in the archipelago as per the objectives bulleted below:
  • To collect information and records relating to the status of all birds observed from the islands of Seychelles and their surrounding ocean (EEZ).
  • To assess reports of all birds considered to be of less than annual occurrence within the Seychelles EEZ and to permanently maintain the original bird record submissions made by observers together with all Committee comments and votes.
  • To publish summary details of all accepted records, encourage publication by observers of first records for Seychelles and to maintain a national list of bird recorded in Seychelles EEZ.
  • To provide all persons or bodies interested in the study of birds in Seychelles with scientific data pertaining to bird sighting records.
  • To increase awareness of and interest in the birds of Seychelles both nationally and internationally.


I liaise periodically with Adrian Skerrett of the SBRC regarding sightings on Denis and on occasion he may request that the observer(s) submit a record sheet if the sighting is of a species that is not considered an annual migrant to the archipelago. The record sheet is then assessed by the SBRC which if it deems there is sufficient evidence to substantiate correct species identification will accept and publish the record. In this vein I have received notice from Adrian that the following recent sightings from Denis have been accepted by the SBRC:

  • Purple Heron (Ardea purpurea) – One immature bird sighted at Belle Etoile, Denis Island on the 3rd October (by Catherina Onezia). This is the 35th record for Seychelles.
  • Ferruginous Duck (Aythya nyroca) – One adult male at the pig farm, Denis Island 25-27 November 2008 (by France Hoareau and John Nevill). This is the 4th record for Seychelles.
  • Eurasian Hobby (Falco subbuteo) – At least one and up to three at the airstrip and over the coast 24-27 November (by Mickey Mason, Catherina Onezia and John Nevill). This is the 20th record for Seychelles, all from late October to early January.
  • Yellow Wagtail (Motacilla flava) – One adult male, probably race beema at the pig farm, Denis Island on 9 December 2008 (by John Nevill and Anne-Marie McDevitt). This is the 29th record for Seychelles, reports spread fairly evenly through the months of October to May.


Of course to get a record accepted it is a great help to have photographic evidence! Thanks to the wonders of modern digital photography this is becoming increasingly possible – see sidebar for photos of the species in question.


The records of the major influx of Amur Falcons (Falco amurensis) to Denis in November of last year have also contributed (amongst many others) to the species now being recognised as an annual migrant to the archipelago. There is an interesting summary of records, pertaining to the mass influx last November, from all over the archipelago to be found on the SBRC website. Simply click on the link below to go direct to the summary:


http://www.stokecoll.ac.uk/sbrc/latest/amur%20falcons.pdf

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