Summary of the follow-up of 3 Harriers species in 2006 in Gironde

The couples of harriers occupy mainly two types of environment in our region, the artificial forest of maritime pines (sowing of pines) on wet moor and the swamps of edges of the Garonne or the Gironde.

Habitat:

After 16 years of follow-up, the forest sites evolved a lot and pines pushed, the prospecting becomes more difficult and the habitat less favorable with the exception of the more or less long-lasting surfaces of moor than it is essential but difficult to protect (interest of the foresters against ours).
It brought us once again this year to increase the surfaces of prospecting around defined zones while following the original zone of study. On the other hand, the discovery of a consequent colony of Montagu's harriers (Thanks to Pascal Grisser who communicated us his observations on his STOC EPS square ) is very interesting and his follow-up was done. (Naujac-sur-mer). The prospecting of a square within the framework of the inquiry "Birds of prey" allowed us to locate two couples of Montagu's harriers in the swamps of the North-Médoc but unfortunately we were unable to follow them.
In the swamps of Blayais, the habitat transformation continues with the increase of the land dedicated to the maïsiculture and thus the drying out of plots of land which always precede the stake in culture. A contact with the local farmers is necessary, notably with M.Cotavos on ST CIERS on Girond, in order to protect these favorable sectors of reproduction but also to guarantee quiet zones for the wintry dormitories of Marsh Harriers. The sudden appearance of big or small fallow lands and their uncertain future also contribute to the fluctuation and to the precariousness of the couples that settle down there (refuge for predators), they are occupied by three sorts of harriers
This is the case of the swamps of Blayais ( Primeraie) but also in the swamps of Ambarès (Grande Palue de Sabarèges) with the progress of the neighboring industrial park northward.

Progress of the reproduction season :

1. Marsh Harrier
29 couples paraded on the study areas, 3 built without laying, 6 failed (1 couple had his unique young victim of mowing, the farmer should have been warned; the female of this couple was native of Blayais and had been marked chick in the swamps), 9 nests saw flying away 18 young birds this is 2 youngs per couples having succeeded and 1,3 youngs for birds having laid. 18 chicks were tagged in wings and ringed
A clutch was protected from clearing by Eric Lenain, agent of the ONF on Salaunes. Layings were more premature than previous years, all in April and even in March. The habitat remain precarious in the swamps of Blayais because of the important human disturbances on the lakes of hunting hut. The forest wet moors are occupied most of the time by the specie.

2. Hen Harrier
The prospecting was not so important for this specie than previous years but there are fewer nesting couples: 5 couples (not followed) reproduced in swamps (one gave flying youngs but not counted), 2 couples in forest (only 2 flying youngs) and we only marked two adults and a young.



3 Montagu's Harrier
26 couples were observed (12 were listed on the zone of study but only 7 built a nest). The new forest zones of prospection welcomed 7 couples and the zone of Naujac, 5 also.

In summary, 24 couples were followed, 20 chicks were ringed and 9 adults were wing tagged.

It was an atypical year with fewer reproductive couples on the zone of study, a little less of 1/3 couples confined but birds were present very late (after August 15th) and the follow-up of zones at the end of July the beginning of August could have revealed surprises.
The first layings took place end of April, beginning of May for the zone of Naujac-sur-mer but also in the last decade of May.
14 nests saw flying away 21 youngs (1,5 y /nest, 1,6 y/couple having laid, 2,1 youngs by couple having succeeded). 10 adults were captured and marked, no control was made during captures. 19 youngs were ringed.

Conclusion:
There was a minimum of 62 couples listed for all 3 species of harriers during the season 2006 and 44 nests were followed.

Thanks to the volunteers of the group who participated in 2006 on the field:

J Beauvilain, C. Beltrami, MF. Canevet, G.Engel, JP. Gans, L. Gontaud, Mr Gouache, R.Guélin, H.Laveissière, B. Laporte, J. and Q. Montaillier, Bernard Noël, enc. Philippon, H. and D.Rodriguez.

Thanks to P. Grisser for its information concerning Naujac sur mer.

You can all help us by communicating us during the season your observations of harriers having breeding behavior. This will allow us to complete our knowledge of the nesting distribution of 3 species of Harriers (mainly for the Marsh harrier nesting distribution of which is not very clear in Landes and Pyrénées- Atlantiques) and for the Montagu's Harrier operation of large-scale marking of the chicks in 2008. See previous LPO Info.

M.Françoise Canevet (For the group " Busards " Gironde LPO Aquitaine)