For a third consecutive year in Bulgaria, the Egyptian Vulture New LIFE team used three release methods to test the release of captive-bred Egyptian Vultures — delayed-release, fostering and hacking. This project will measure birds' relative survival under the three different techniques to help the team understand the best method for eventually restocking the small population of 60 pairs left on the Balkan peninsula.
2020 Delayed-release method results
In 2020, the project team released three captive-bred Egyptian Vultures in the Eastern Rhodopes, applying the delayed-release method – Izi, Zara and Sofia. Izi was released in her 2nd calendar year (CY) while Sofia and Zara were in their 3rd CY.
Sofia died from electrocution only 20 days after her release. Overall, she could not adapt well to the conditions in the wild. After the release, Sofia did not visit the supplementary feeding station and did not learn to roost on remote safe places. She was also very tolerant of human presence.
Zara experienced difficulties finding food in the wild during the first few weeks after the release, so she had to be recaptured. She was released again by the WWF-Greece team at the supplementary feeding station in Dadia, and managed to adapt well ever since. Zara started her autumn migration in mid-September and used the traditional migratory route through Turkey. However, she stayed on the Adrasan Peninsula for almost a month, moving from one end of the peninsula to the other, trying to find a way out. Then she followed the flyway along the eastern Red Sea coast and settled in Saudi Arabia for wintering.
Izi adapted the best to the wild out of the three vultures freed with the delayed-release method. She was regularly visiting the supplementary feeding station at the release site and exploring the Eastern Rhodopes area well. She started her migration in the second half of August, following the traditional migratory route through Turkey. Like Zara, she got trapped in the Adrasan Peninsula for over a month. However, she did not try to cross the sea and managed to find her way along the coast towards the Middle East. Izi reached Egypt and settled for the winter near the Nile north of Lake Nasser.
2020 Fostering release
In 2020, two captive-bred Egyptian Vulture chicks, Neli and Simeon, were fostered in two wild nests in the Eastern Rhodopes. The parents and their wild siblings named Anahita and Sava immediately accepted the captive-bred vultures.
The wild chick Anahita fledged in mid-August while its new sibling Neli fledged in early September. Both chicks chose the traditional migratory route through Turkey. However, Neli reached the Adrasan Peninsula and could not find the right way out of it towards the northeast. Instead, she followed the coast to the northwest and reached the island of Rhodos. She tried to cross the sea but unfortunately drowned. Meanwhile her wild sibling Anahita followed the coast through the Middle East but was shot by poachers in Lebanon. She was rescued and survived but will not be released into the wild due to her injuries. Instead, she will be kept in captivity and will enter the captive-breeding programme for the species.
Sava, the wild chick from the second nest, fledged only five days after the introduction of the captive-bred sibling. Sava migrated through Turkey and the Middle East. He settled for the winter in Sudan. Simeon fledged in early September, but he decided to migrate through Greece, managing to cross the Mediterranean Sea between Greece and Lybia (roughly 613 km over the water). Simeon continued south through Chad and reached his wintering grounds in Zinder region, Niger, only 23 days after the start of his migration.
In 2020, only one captive-bred Egyptian Vulture was released in the Eastern Rhodopes through the hacking method – Deni. For the first time, the vulture was released from the adaptation aviary previously used for delayed-release, which is situated at the central supplementary feeding station in the area. Deni adapted well to the conditions in the wild and immediately took advantage of the food provided at the feeding station. Deni started its migration journey in mid-August, also migrating through Turkey and reaching Adrasan Peninsula, but immediately managed to find the way out, unlike Zara and Izi. Then, it continued through the Middle East and eventually arrived at its wintering grounds in Chad.
Results of Egyptian Vulture release methods
Over the course of the past three years (2018-2020), 20 captive-bred Egyptian Vultures were released in the Eastern Rhodopes, Bulgaria. Ten vultures were released through the delayed-release method, 6 through hacking and 4 through fostering. 75% of the vultures released by fostering survived during their first autumn migration and reached their wintering grounds, 70% of the delayed-released vultures survived their first migration south, while the survival rate of the birds released through hacking was only 33.3%. The survival rate of the wild juveniles tagged in the same period was 50% (n=4). Based on the criteria for success set for each method and these preliminary results, the project considers fostering and delayed-release as successful methods for release of captive-bred Egyptian Vultures while hacking as unsuccessful.
All birds are donated to the project by the Egyptian Vulture European Endangered Species Programme (part of EAZA's EEP), coordinated by Antonin Vaidl from Prague Zoo. The Green Balkans' Wildlife Rehabilitation and Breeding Center also provides some of the birds that hatched in their facility.
As part of the Egyptian Vulture New LIFE project, we at the Vulture Conservation Foundation are supporting and contributing to the comprehensive experiment that aims to test the different techniques of releasing captive-bred Egyptian Vultures.
Source: Egyptian Vulture New LIFE
Egyptian Vulture New LIFE
Working collaboratively, projects like the Egyptian Vulture New LIFE aims to reinforce the Egyptian vulture population in their Europe's easternmost range across the Balkans. By actively managing and restocking the population by releasing captive-bred birds, the project will support the small Balkan population, which numbers between 60 and 80 pairs across the whole region. The project is working to deliver conservation measures that eliminate major known threats such as illegal poisoning and electrocution in their summer breeding grounds. Monitoring the population closely using GPS tags will also help the project tackle the major threats Egyptian Vultures face. The Egyptian Vulture New LIFE is a partnership of organisations, led by the Bulgarian Society for the Protection of Birds from 14 countries spanning Europe, the Middle East and Africa, to protect the species not only in Europe but all along their migratory flyway.