martes, 17 de junio de 2014

Heaven and hell: breeding failure of the Audouin's Gull colony at Llobregat Delta

Rangers of the Generalitat de Catalunya (Agents Rurals) searching for alive chicks in the colony 13.6.2014 © Ricard Gutiérrez

608 Audouin's Gull Larus audouinii nests. That was the 2014 count which marked a local record for the species in its 'new' breeding site at El Molí island of Llobregat river mouth. colonised by the species in 2009. Ringing of the colony was scheduled for June Friday 13. And the friday 13 reputation seemed to work again: almost no activity in the colony showed that something had went wrong.

The colony had a great number of abandoned nests, some broken as 'crashed by something coming from the sky', some predated but probably 'after-death' according to the official Vet and Mammal expert that visited the colony. There were a few abandoned nests with very young dead chicks at least two weeks before the visit, according to the condition of the corpses .

Failure was not complete, since 21 chicks could be found and were subsequently ringed with white PVC rings coded as follows:

BR4J, BR4L, BR4Z, BR4Y, BR4X, BR4W, BR4V, BR4U, BR4T, BR4R, BR4S, BR4P, BR4N, BR4M, BU1S, BU1U, BU1J, BU1S, BU1X, BU1M, BU1W.

Larus audouinii chick. Llobregat delta, 13.6.2014 © Ricard Gutiérrez
One of the ringed Larus audouinii chicks, Llobregat delta, 13.6.2014 © Ricard Gutiérrez


The joint team of Llobregat delta Consortium, Wildlife Service of the Generalitat de Catalunya and Rangers of the Generalitat stated that a set of five-days in a row of heavy showers, including hail, and low temperatures coinciding exactly with hatching period of the species in late May 2014 is after the colony fate. This had happened years before in the Ebre Delta, with a total failure of the world largest colony, and has happened here for the 1st time ever.

Meteo.cat radar showing the storms of 26.5.2014
Meteo.cat radar showing the storms of 31.5.2014
 
Regardless the disgraceful situation, this fact demonstrates how conservation dependant these colonial species are. And how, despite seeming to be leaving its former endangered status, there is still much to do for the benefit of colonial threatened seabirds such as the Audouin's Gull. Let's see what happens next year. Let's hope it will be better for the species in this important stronghold the Llobregat delta is.