At the Vulture Conservation Foundation, we have been following the expansion of the Rüppell’s Vulture (Gyps rueppellii) from Central Africa to Southern Europe over the last decades. Are these vultures searching for a safer haven to escape the threat of extinction in Africa? Or are they encountering a potential “genetic amalgamation threat”? Today, we present key insights from a newly published scientific paper (Muñoz et al., 2023), initially unveiled at the European Vulture Conference 2023, offering insights into this complex case.
How bright is the future of Rüppell’s Vultures in Europe?
The Rüppell’s Vulture is globally classified as “Critically Endangered” according to the IUCN’s Red List of Threatened Species, the last category before global extinction. Native to African countries, including Mauritania, Senegal and Guinea, to Sudan, Ethiopia, Kenia and Tanzania, the species inhabits open savannahs, semi-arid lands or the periphery of deserts and rocky areas. It is easy to imagine the Rüppell’s thriving in similar southern Iberian landscapes and climate conditions.
Highly sociable and with a natural tendency to expand horizons, the Rüppell’s spotted in Europe are believed to have arrived amidst a flock of other migratory birds, eventually Griffon Vultures (Gyps fulvus). Slightly smaller than the Griffon and with darker and mottled brown plumage, the two species share many phenotypical traits, and it is sometimes difficult to tell them apart when they circulate in the same updraft at high altitudes.
The expansion of the Rüppell’s Vulture in Europe
The first Rüppell’s Vulture seen in Spain was reported over 30 years ago, in 1992. Since then, the species has been observed mainly in southern Spain and Portugal, and was seen for the first time in Italy in 2019. It is fair to call it now “Europe’s 5th vulture species”, as there have been breeding attempts with Rüppell’s Vultures in Cádiz and Málaga since 2020.
There is, however, an important fact: all Rüppell’s Vulture individuals breeding in Southern Spain were paired with Griffon Vultures. Like Juanita, a female Rüppell’s who has permanently settled in Spain, and tried to breed with a Griffon Vulture.
Throughout 2021-22, breeding attempts by mixed pairs have consistently occurred at a breeding colony in Málaga, but close monitoring of the individuals confirmed that mating did not result in egg-laying.
Muñoz et al., 2023
Could a Rüppell’s successfully breed with a Griffon Vulture?
According to the authors, a tagged Rüppell’s male was observed mating with a female Griffon Vulture at the end of 2022. She successfully laid a fertile clutch, and the pair started incubating. Once the chick hatched, parents shared responsibilities in rearing and feeding, and the fledgling left the nest in September this year.
It is the first confirmed case of successful breeding of the two species in the wild!
Muñoz et al., 2023
Until now, all breeding pairs observed in the wild in Spain were mixed, and authors suggest that hybridisation “will probably continue or even increase in Europe”. Especially if we consider the population size of Griffon Vultures in Spain, the largest in Europe by far, with 30.100 – 36.500 breeding pairs estimated (Vulture population estimates, VCF, 2022).
“Escaping from extinction or entering a genetic amalgamation trap?”
The title is extracted from the paper recently published (Muñoz et al., 2023). African vulture species are, unfortunately, in a negative trajectory. Several Critically Endangered species might become extinct in the coming decades if no conservation action is taken to mitigate the main threats affecting vulture survival. The Rüppell’s might be finding a way out of a dangerous Africa.
However, when a mixed pair successfully produces a chick, “the hybrid offspring could be sterile or breed mostly with Griffon Vultures”. This could lead, for instance, to the extinction of the species in Europe through “genetic amalgamation” (Muñoz et al., 2023). The authors recommend transcontinental efforts to monitor and follow the species from close and call for an international Action Plan.
A truly explorer: the (love) story of a Rüppell’s in South Africa
The paper’s authors shed light on a curious episode in 1994 when the first Rüppell’s Vulture was spotted in South Africa. A couple of years later, a male was observed mating…with a female Cape Vulture (Gyps coprotheres), although breeding was never confirmed. However, in 1999, a Rüppell’s Vulture was seen in the same area, this time incubating close to a Cape Vulture. There are records that the mixed pair successfully fledged offspring in two breeding seasons!
Monitoring and following the species in Europe and Africa: insights shared at the European Vulture Conference
The European Vulture Conference was an opportunity to hear the latest research findings and developments from those following Rüppell’s Vultures’ expansion in Europe.
On Day 2, two standard talks were dedicated to the Rüppell’s Vulture, with presentations from Sandro López-Ramírez about the potential long-term establishment of the species in Europe, and Michell Marcano Delgado, who presented an analysis of the spatiotemporal movements and home range of Rüppell Vultures in Europe.
On Day 3, José Garrido presented conservation efforts needed for the species along the Western Flyway, shedding light on the main threats affecting the species while wintering in Africa, namely power lines, windfarms, human persecution, and poisoning. There was also a parallel session entirely dedicated to the species, with Antonio-Román Muñoz presenting the successful reproduction of a mixed pair this year in Spain; Alejandro Onrubia suggested that climate change-induced floods in the Sahel and the increasing proportion of Griffon Vultures might be facilitating the species expansion in Europe. Juan Ramírez presented the results of a breeding population in northern Senegal, alerting for the population decline in West Africa and the need for further research. Maarten Vis highlighted the efforts of European Zoos in breeding the species in captivity. The last season yielded encouraging results, with 15 chicks hatched—a crucial contribution to securing the species’ genetic diversity.
Sources:
Antonio-Román Muñoz, Juan Ramírez, and Raimundo Real “A Critically Endangered African Vulture Starts Breeding in Europe: Escaping from Extinction or Entering a Genetic Amalgamation Trap?,”Ardeola 71(1), 131-135, (28 November 2023). https://doi.org/10.13157/arla.71.1.2024.fo1
