Six more Cinereous Vultures join the soft release programme to strengthen the Douro International colony

Fotografia: New group of Cinereous Vultures acclimatising in the Douro International Nature Park. ©LIFE Aegypius Return

Last week, a new group of six Cinereous Vultures (Aegypius monachus) joined the acclimatisation programme in the Douro International Nature Park where the most fragile breeding colony in Portugal is located. This is a pioneering vultures conservation strategy in Portugal, implemented as part of the LIFE Aegypius Return project.

Encouraging vultures to settle in the territory

In 2024, the Cinereous Vultures acclimatisation station built in Fornos, in the municipality of Freixo de Espada à Cinta, was inaugurated as part of the LIFE Aegypius Return project. This station consists of a large aviary (18 metres long, 9 metres wide and 6 to 8 metres high), located next to a feeding station for scavenging birds. The structure allows Cinereous Vultures to stay for several months in conditions that ensure their safety and well-being. During this period, they can observe and interact with their conspecifics and other species outside, socialising and learning natural behaviours such as feeding and recognising dangers.

The goal is for these vultures to become attached to the Douro Internacional territory and ultimately reinforce the local breeding colony, the most fragile in the country. This fragility is due to its isolation—the nearest colony is over 100 km away in Spain—and the small number of breeding pairs.

Which vultures undergo acclimatisation?

All the vultures in the acclimatisation programme are juveniles with unknown origins that were taken in and treated at wildlife rehabilitation centres. The reasons for entering these centres vary, but the most common is exhaustion and disorientation. After leaving the nest, some juveniles undertake very long dispersal flights, during which they may struggle to find food or suitable habitats for resting. As a result, they are often found near the sea or in areas where they are not typically present, including urban zones. This explains why, in autumn 2024, Cinereous Vultures were observed in Peniche, Almada, Loures, and the Algarve, for example. Despite attempts, it is not always possible to rescue these vultures. In such cases, the only option is to hope they regain strength and manage to survive.

When authorised technicians or the authorities (GNR - Guarda Nacional Republicana and/or ICNF - Instituto da Conservação da Natureza e das Florestas) manage to rescue these weakened or even injured vultures, they are taken to rehabilitation centres. After their recovery, their release into the wild is delayed for a few months while they undergo a slow and phased adaptation process (acclimatisation). This delayed release is known as soft release.

Cinereous Vultures recovering at RIAS. ©RIAS

Six Cinereous Vultures in acclimatisation

This year, six Cinereous Vultures are part of the LIFE Aegypius Return acclimatisation programme.

One was found near the sea in Armação de Pêra, in the Algarve. It was delivered by the ICNF rangers of the Ria Formosa Nature Park to RIAS, the recovery centre run by the ALDEIA Association in Olhão, in a very debilitated and exhausted state.

Another Cinereous Vultures was found in the Alqueva dam, almost drowned. It was transported to CARAS - Centre for Reception and Rehabilitation of Wild Animals, run by LPN - Liga para a Protecção da Natureza in Évora, where it received first aid and was stabilised. From there it was transferred to CRAS-HVUTAD - the Wild Animal Recovery Centre at the Veterinary Hospital of the University of Trás-os-Montes and Alto Douro, and then to CIARA - the Centre for Environmental Interpretation and Animal Recovery, where it completed its recovery.

The CRAS-HVUTAD and CIARA teams also treated a Cinereous Vultures with a complicated injury that required surgery: torn ligaments that almost prevented it from flying again. The bird was initially taken in at the Wildlife Rehabilitation Centre of Gaia Biological Park, where it received initial treatment.

A fourth Cinereous Vultures was rescued by ICNF teams in the Vidigueira area, very close to the most recent colony of the species in Portugal, discovered in June 2024. It was rehabilitated at CERAS - the Centre for the Study and Recovery of Wild Animals, managed by Quercus, in Castelo Branco.

Another juvenile Cinereous Vulture, found debilitated in São Facundo, Abrantes, was also taken to CERAS by the ICNF team from Ponte de Sôr.

Finally, the sixth vulture to join the acclimatisation programme this year was found weak and disoriented in the Cadaval area and delivered by SEPNA - the GNR's Nature and Environmental Protection Service, from Alenquer, to CRASM - the Montejunto Wild Animal Recovery Centre, run by Quercus. It was later transferred to CERAS, in Castelo Branco.

After a final veterinary check-up, biometric measurements, biological sample collection, and ringing (to allow individual identification), all these vultures were placed in the acclimatisation aviary and will be carefully monitored through video surveillance by the LIFE Aegypius Return teams, and in particular by Palombar, the entity responsible for managing the project's acclimatisation programme.

Final veterinary check-up, collection of biometrics and biological samples, before the vultures enter the acclimatisation aviary. ©LIFE Aegypius Return

Does acclimatisation work?

In Portugal, this conservation strategy - which uses wild birds born in the wild - has never been tested on vultures or large raptors. However, previous experiments carried out with Cinereous Vultures in other countries (e.g. Bulgaria, France) have shown that soft release is more effective in settling individuals in a given territory than immediate return to the wild, and is the recommended method for accelerating settlement and increasing the viability of a population.

The four Cinereous Vultures that were acclimatised in the Douro International in 2024 are still too young to breed. However, since their release, three have remained in the Douro International region. Only the female Alfavaca has moved eastwards, and is currently about 280 kilometres from the Douro International.

Movements of the four Cinereous Vultures acclimatised in Douro Internacional in 2024, from their release in November 2024 until March 2025. Blue – Azedinha; Green – Arçã; Red – Almeirão; Purple – Alfavaca.

This conservation programme is only possible thanks to the work of the recovery centres’ teams and the coordination between the authorities and all the entities involved. The partners of the LIFE Aegypius Return project extend their gratitude and recognition to all individuals and organisations for their fundamental work.

Thanks are also due to all those who took part in the event to transfer the new group of Cinereous Vultures to the acclimatisation station on 19 March. Attendees included project partners Palombar, as hosts and managers of the acclimatisation programme; VCF - Vulture Conservation Foundation, as coordinators of the LIFE Aegypius Return project; ATN - Associação Transumância e Natureza; SPEA - Sociedade Portuguesa para o Estudo das Aves; LPN – Liga para a a Protecção da Natureza; GNR - Nature and Environment Protection Team (EPNAZE) of the Douro International Natural Park (PNDI) / SEPNA of the Bragança Territorial Command. We also appreciate the presence and hospitality of the Freixo de Espada à Cinta Municipality and the Fornos and Lagoaça Parish Council, as well as the ICNF – technicians and rangers from the Northern Regional Directorate/PNDI. A special thanks is also due to the teams of the wildlife rehabilitation centres for their participation, care of the birds and support in their transfer: CRAS-HVUTAD, CIARA, CERAS, and RIAS.