Friday, 13 November 2015

A new Avian Species Record for Barbados – the Western Marsh Harrier (Circus aeruginosus) by Dr. Webster

Photograph by Dr. John Webster

On Thursday 5 November we added yet another species to the record of avian species seen on Barbados. The new species is the Western  Marsh Harrier (Circus aeruginosus). The photographs presented here represent the photographic record of this sighting. Unfortunately the photos are not up of the highest quality as Thursday was a heavily overcast and rainy day with terrible light for photography and most photos had to be taken into the light. However, they are what they are, a documentary record of the first sighting in Barbados, of yet another rare European species for our region.

Photograph by Dr. John Webster
The bird was first seen by me at about 10.00am sitting in a cow pasture in the Golden Grove area in the eastern part of the island. It then took flight and for the next 45 minutes circled and hunted over the Golden Grove private impoundment, hovering at times very low and then regaining altitude for further circling. The swamp area has become rather overgrown in recent months with an assortment of sedges, rushes and other vegetation, thereby creating a habitat similar to that favoured by this species. During the time it hunted, I never saw it catch any prey.

The following morning Richard Roach and I returned to the site and once again we observed the Harrier at about 6.30am. It continued its behaviour as per the day before but never approached close enough for any decent photos. We have returned to the location several times since but it has never been seen again.
Photograph by Dr. John Webster

The Western Marsh-Harrier (Circus aeruginosus) is a Eurasian species rarely recorded in the Western Hemisphere. It appears that there have only been about 5 previously recorded sightings of this species in the Caribbean.  The first fully documented record was a female Western Marsh-Harrier, found and photographed at Grand Cul-de-Sac Marin on the island of Guadeloupe on 14 December 2002 and again on 19 January 2003 by Anthony Levesque and Frantz Delcroix. The second and third records were a female at the Laguna Cartagena National Wildlife Refuge in Puerto Rico from 14 January to 30 March 2004 and an immature at the same locality from 11 January to 11 February 2006 (Merkord, Rodriguez and Faaborg, Journal of Caribbean Ornithology 19:42-44, 2006)

).  Prior to this latest sighting in Barbados, two other sightings were recorded in eBird for this year, both from from Guadeloupe:  at Ilet Christophe, Guadeloupe, Wed Oct 14, 2015 by Gomès Régis and at Baie-Mahault birnhingam, Guadeloupe, Sat Oct 17, 2015 by Frantz Delcroix (Duzont). It is very likely the bird observed here in Barbados may be the same bird observed on two occasions in October on Guadeloupe, making its way southward through the chain of islands.

According to the Hawkand Owl Trust, the Marsh Harrier (Circus aeruginosus) a large harrier, is making a slow but steady localised recovery from extinction in the early 19th century. The largest harrier found in the UK, the population is at its highest for 100 years, but still low and very localised. Since its recovery the Marsh Harrier has adapted its behaviour, with individuals wintering in the UK and breeding on farmland as well as traditional reedbed habitats. Marsh Harriers can be found in large numbers at the Hawk and Owl Trust’s, Sculthorpe Moor Community Nature Reserve in North Norfolk.

Slightly larger than a Buzzard, Marsh Harriers can be distinguished by their longer tail, slimmer body and narrower wings. Females are dark brown with a distinctive cream coloured crown and pale patches on the forewing and throat. Males have dark wing tips and grey tail, the breast and head appear yellowish with a brown belly, the upper-wing is a combination of black, grey and brown. Juveniles are dark brown with a golden crown and throat and a pale leading edge to the wing. Length: 47-57cm; wingspan: 115-140cm.

Status in UK
370 breeding females (2005), increasing but localised; AMBER listed; resident and summer visitor

Population Trends
Extinct in the UK by the end of the 19th century due to habitat loss and persecution, occasional nesting pairs returned to eastern England during the 1970’s. Numbers have increased steadily since then with birds adapting to different habitats for nesting. Many birds now overwinter and large roosts can be seen in some areas, especially in eastern England.

Habitat and Distribution
Mainly found in areas of reed bed, although as mentioned they also now frequent and breed on farmland. Main populations are in Norfolk, Kent, Lincolnshire, Humberside, Lancashire and Southern Scotland.

Originally nesting on the ground in reed beds, Marsh Harriers also nest in crops. Breeding pairs carry out impressive displays of aerobatics, tumbling through the air with the male dropping food for the female to catch in mid-air.

Females have a single clutch of 4-5 eggs and start to breed at 3 years of age. Males are not monogamous and will sometimes mate with 2 or 3 different females.
Marsh Harriers feed on small mammals and birds, preferring prey that is easier to catch. They will also take reptiles, insects and carrion.

See more of Dr Webster's images below