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Swamp Harrier

SWAMP HARRIER

Busard de Gould - Photo Alain Petit

Busard de Gould – Photo Alain Petit


APPEARANCE AND IDENTIFICATION
Busard de Gould@Mikaël Tréguier

Swamp Harrier@Mikaël Tréguier

25 inches. Male and female identical in appearance but the female is larger than the male. This is the only diurnal raptor introduced in Polynesia. It is a brown bird, large-scale, often glides at high altitude. Its beak is strong and curved downward. The plumage presents various shades of brown and is variable according to the individuals. The iris and legs are light yellow. First winter juveniles have brown irises, dark brown plumage with a white patch on the nape of the neck. As they get older, the color of their iris and plumage fades.

Order: Falconiformes

Family: Accipitridae

Category: Introduced Birds


LOCATION

Native from New Zealand, it was introduced in Tahiti in 1885 by the German Consul with the intent to limit the number of rats. From this island, he joined the other islands without human intervention for the greater misfortune of their endemic avifauna. Present in Maupiti, Bora Bora, Tupai, Raiatea and Tahaa, Huahine, Moorea, Tetiaroa. In Rapa, an introduced couple was killed a few months after his arrival.


CHARACTERISTICS

It hunts in the valleys, plantations, near the villages and other habitats such as seashores.

Silent in general, it makes high-pitched sounds as “kee, kee …” during the breeding season.

To listen the Swamp Harrier:
http://www.xeno-canto.org/species/Circus-approximans

Large insects, lizards, birds, rodents. Fish and occasionally carrion.

In September-November in Tahiti. In New Zealand breeds in October-November, it can begin as early as August in regions further north in the country. Nests on branches, grass and reed. The reproduction was studied in New Zealand. The female incubates 3-4 eggs chamois for 29-32 days. Incubation begins with the laying of the first egg. Chicks are thus of different sizes and younger – smaller – rarely survive. They fly at the age of six weeks. A laying of two eggs was found in French Polynesia.

Original text by Caroline BLANVILLAIN – Supplements and update by various members of the SOP Manu.

Bibliography :

https://inpn.mnhn.fr/espece/cd_nom/432707/tab/statut
http://avibase.bsc-eoc.org/species.jsp?avibaseid=1ACF5A6EA3C82C25
http://www.oiseaux.net/oiseaux/busard.de.gould.html
http://datazone.birdlife.org/species/factsheet/swamp-harrier-circus-approximans
http://www.hbw.com/ibc/species/swamp-harrier-circus-approximans
https://www.iucnredlist.org/species/22695363/111781121

NAMES

Scientific Name: Circus approximans (Peale, 1848)

Polynesian Names:
Amu mo’a, manu ‘amu mo’a, ou’ai mo’a (Tahiti)

LOCATION
  • Society
  • New Zealand (native)
  • Australia
  • New-Guinea

STATUS AND PROTECTION
Common species in the Australasian region, the Swamp Harrier is suspected of being behind the disappearance of imperial pigeons Ducula in all Pacific islands where it was introduced. In Tahiti, the Swamp Harrier is probably responsible for the near extinction of the rupe (D. aurorae). He was seen capturing Tahiti Reed-warblers (A. caffer, species in danger of extinction) and causes alarm calls from the Tahiti Monarchs (Pomarea nigra species critically endangered). Endemic birds of the islands have evolved in environments free of predators, they have not developed during their evolution techniques to escape. They are often easy prey. Lorikeets (Vini sp.), Reed-warblers (Acrocephalus sp.), Swiftlets (Aerodramus sp.) and Fruit-doves (Ptilinopus sp.) are probably also its victims. Without his presence rodents could spread around islands: this argument is often the cause of its introduction. It could permanently eradicates the last surviving imperial pigeons on Nuku Hiva and Makatea (Ducula galeata and D. aurorae) or the magnificent Ultramarine Lorikeet and Rimatara Lorikeet (Vini ultramarina and V. kuhlii).

Its presence in these archipelagos or islands must be reported as soon as possible to the Direction of the Environment or to the SOP. The species was classified harmful in French Polynesia (see l’arrêté N°1301/CM du 15 novembre 2006), its destruction is permitted and desirable. The species is on the list of species threatening biodiversity through territorial regulatory French Polynesia.
It is classified as “Least Concern” (LC) on the IUCN Red List.