Two black kites raised with double-nursery technique arrive in Mauritania after migration from Madrid

These are days of celebration among the professionals of the Félix Rodríguez de la Fuente Wild Animal Recovery Center (CRAS) of the Community of Madrid thanks to two specimens of black kite and their 'journey' of thousands of kilometers from Tres Cantos to Africa. The birds of prey entered the regional facilities as orphaned offspring and the technicians of the regional raptor recovery program applied a breeding technique called 'double nurse' with them to guarantee their viability.

The birds prospered, became adults and were released into the wild with a GPS transmitter that has now made it possible to locate them earlier this month in Mauritania, a key wintering region for Iberian populations. "This confirms that black kites raised with the double-nursery technique keep their migratory abilities intact," they explain from the Ministry of the Environment, on which CRAS depends. "It is a critical aspect to evaluate the effectiveness of assisted breeding programs in raptors, as well as their ability to interact with other specimens of their species," they add from the department directed by Carlos Novillo.

Recovery with nurse nests is based on the natural adoption of orphaned chickens or those that have fallen from the nests by breeding specimens. This allows the young specimens to grow in a fully functional environment, developing behaviors typical of their species.

With double nursing, the procedure acquires 'complicity': the chickens to be recovered are initially raised with a female of another species, which is normally selected for its high quality as a nurse and for the high rate of success in breeding, and with siblings of the same species. Afterwards, they begin the flight and hunting phase with adult specimens of black kite and red kite, with which they coexist in nature.

"This milestone consolidates the Madrid program as a national reference in assisted breeding applied to raptors," they emphasize from the Environment, which details that the wet-nurse technique is widely applied in the rehabilitation and breeding of juvenile raptors, but the novelty of this case is the use of the double-nurse technique.

The high-precision GPS transmitters attached to the black kites that are the protagonists of this advance have made it possible to document each phase of their migration. They left Madrid after completing the acclimatization and flight training period at CRAS and headed towards the south of the peninsula. They successfully crossed the Strait, where the most demanding stages of travel occur for juvenile raptors, and subsequently traveled through Morocco and the Atlas. Several stops were recorded in traditional feeding areas before entering the Sahel and arriving in Mauritania, where they will spend the cold months.