As the Cinereous Vulture colony in the Douro International grows, so does cross-border cooperation to protect it

Palombar and the Portuguese and Spanish authorities are stepping up their collaboration to monitor Portugal's most fragile Cinereous Vulture breeding colony.

The Douro International Cinereous Vulture (Aegypius monachus) breeding colony was the second to be established in Portugal in 2012, four decades after the species became extinct as a breeder in the country. For many years, the colony had only one pair, which didn't always breed successfully. In 2019, the colony grew to two breeding pairs and then increased to the eight pairs recorded in 2024. However, this remains the most fragile colony in the country, as it is the most isolated, located more than 100 kilometres from the nearest colony in Spain. The isolation and small size make this colony very susceptible to various risks, and it is essential to ensure its protection.

Douro River canyon ©Paulo Monteiro/SPEA

A river that unites

In this region, the imposing canyon of the River Douro marks the border between Portugal and Spain. However, for the vultures and those who protect them, the territory is one. On the Portuguese side, teams from the Northern Regional Directorate of the ICNF (Institute for Nature Conservation and Forests), in particular from the Douro International Nature Park (PNDI), work closely with biologists and technicians from the Palombar association. In Spain, the Junta de Castilla y León (JCyL) and their teams from the Arribes del Duero Natural Park (PNAD) join this conservation mission. Together, they monitor and protect the region's rich biodiversity and, as part of the LIFE Aegypius Return project, join forces to safeguard the Cinereous Vulture, in a true example of cross-border cooperation.

Technical visit to the Douro International Nature Park ©VCF

Exchange experiences to save vultures

To prepare for the upcoming breeding season, Portuguese and Spanish teams recently gathered in the PNDI. A technical visit was also carried out to the acclimatisation aviary, which will soon receive another group of Cinereous Vultures. There, discussions focused on aspects related to the birds’ welfare, feeding, and video surveillance. The teams also visited the artificial nesting platforms built in the PNDI to attract new breeders and provide safe nesting sites. These structures are of particular interest to specialists in climbing and working at height, who had the opportunity to exchange experiences and discuss approaches to these highly challenging tasks, carried out on the steep cliffs.

The group also took time to discuss the threats faced by vultures and ways to collaborate on their mitigation. One of the persistent threats is the presence of multiple power lines crossing the Douro River, some of which lack adequate markers, leading to fatal collisions for these large soaring birds. A stark reminder of this danger is the case of Freixo, a Cinereous Vulture chick that died in early 2024 after a violent collision with one of those power lines. During the visit, dozens of Griffon Vultures were observed flying above and below the power lines, prompting discussions on improved marking strategies to be reinforced with the relevant entities.

Analysis of power lines posing a collision risk for vultures in the Douro International Nature Park ©VCF

Group photo during the technical visit to the Douro International Nature Park ©VCF

Monitoring scavenger birds

For over 25 years, the monitoring of scavenging birds in the Douro International has been carried out through coordination and cooperation between the two Natural Parks, and 2025 will be no exception. From strategic observation points and by boat, the various teams share efforts to closely monitor the birds' breeding and precisely define all reproductive parameters.

In 2024, Cinereous Vultures bred for the first time on the Spanish side of the cliffs, producing two chicks. One of these chicks was tagged and named Arribes, in an effort that also included the University of Oviedo and CRAS-HVUTAD (Wild Animal Recovery Centre of the Hospital Veterinary of the University of Trás-os-Montes and Alto Douro), as well as other partners in the LIFE Aegypius Return project, who collaborate in the remote monitoring of the birds.

Jacinto: the senior vulture

The monitoring of the GPS/GSM transmitters fitted to Cinereous Vultures allows for the detection of unusual movements and the timely rescue of a weakened bird or, in other cases, signs of immobility. If a transmitter remains stationary, the bird may have died – which will trigger legal procedures to investigate the cause of death – or the transmitter may simply have detached.

This was the case with Jacinto’s transmitter, which became immobile in February 2024, in a dense forest that is home to a breeding colony of Cinereous Vulture in the province of Salamanca. Jacinto is a Cinereous Vulture well known to the LIFE Aegypius Return teams. He was ringed in January 2006, upon arrival at RIAS (Centre for the Recovery and Research of Wild Animals) in the Algarve in a very weak condition. He was released after his recovery and was found again in March 2021, again exhausted, near Salamanca. This time, he showed signs of being a breeding bird, making his return to the wild urgent. He was rehabilitated at the Las Dunas Wildlife Recovery Centre, managed by JCyL, and released two days later, this time with a name (Jacinto) and a transmitter on its back. When the transmitter stopped moving in February 2024, there were fears that Jacinto, an adult of at least 18 years of age, had died. During the breeding season, it is crucial to minimise disturbance near nesting areas. However, in this particular case, it was important to determine whether Jacinto was in distress or had perished.

Initial remote observations by JCyL technicians could not confirm whether Jacinto was still at the site. In April, field verification revealed that the transmitter was emitting from the top of a pine tree supporting a nest that appeared unused that year. The location was extremely difficult to access, and without proper equipment, it was impossible to determine whether Jacinto’s remains were at the top of the tree. Fortunately, there were no signs of his death nearby, so it was decided to wait until the end of the breeding season for a more thorough search.

In October 2024, thanks to the persistence of JCyL's teams specialising in work at height, it was finally possible to climb the pine tree, retrieve the transmitter, and confirm that there were no bones, feathers or any sign of Jacinto's death. So, for now we can only hope that he continues to soar and breed – and perhaps surprises us with another visit in the future.

The LIFE Aegypius Return partners would like to thank all the technicians and organisations involved in this cross-border collaboration and congratulate them on their effective coordination of efforts.