Recent decades have seen the colonisation of the Iberian Peninsula by a number of African birds, as well as vagrancy from an ever-broader range of species. This rapid change to Europe's avifauna has been fascinating for birders, but also a stark example of the effects of climate change on bird populations.
Each African bird species which gains a foothold on European soil, or even makes a one-off appearance, holds significance as a potential indicator the impact of climate change on ecosystems. Climate models predict increased aridity and further severe droughts in North Africa, as well as southern Iberia, meaning it is unlikely that we have seen the last rapid changes to bird distributions.
Red-rumped Swallow is the most successful African colonist in Iberia, but it only began to breed in 1920 (Benjamin Lucking).
Barriers and frontiers
Although southern Iberia and North Africa share similar landscapes and climate conditions, the Alborán Basin of the Mediterranean, and a small corner of the Atlantic, are enough to form a daunting barrier for many birds. Even the Strait of Gibraltar, less than 13 km wide at its narrowest point, is a difficult crossing for some species.
The Sahara Desert poses another obstacle for potential colonists from further south. These natural blockades, as well as others such as human-related pressures and the availability of suitable habitat, mean that those species capable of long-distance movements stand a much better chance of reaching, and maybe even establishing themselves, in Europe.
The arrival of African birds has been a feature of Iberian ornithology throughout the 20th century and into the new millennium, with several species becoming part of the peninsula's avifauna over time.
It is thought that most African vagrants reach Iberia from Morocco or western Algeria. The former country holds 63 species not found breeding in Iberia, though 22 of these have already been recorded in Spain or Portugal, highlighting the potential for several more species to become established.
These species making it to Iberia from the Afrotropics tend to be waterbirds, with four African rallid species for instance, or raptors such as Rüppell's Vulture, first recorded in the early 1990s but now a regular visitor. More recently, there have been accepted records of immature White-backed Vultures and sightings of Hooded Vultures, though birds of captive origin have clouded the last species' status.
It is a realistic possibility that Rüppell's Vulture might breed in Spain in the coming years, despite its Critically Endangered global status, with plenty of Griffon Vultures around to continue escorting them out of Africa.
Rüppell's Vulture (right, foreground) has transitioned from a very rare vagrant to a regular scarcity, with immatures often tagging along with Griffon Vultures (Stephen Daly).
Home from home
Six bird species of African origin have already established healthy populations in Iberia, with three others now gaining their foothold.
Now part of the scenery in Iberia, it is easy to forget that Black-winged Kite and Red-rumped Swallow only began to spread from Africa in the 19th and 20th centuries respectively. Swifts make up three of the other successful colonists, with White-rumped Swift following Red-rumped Swallow and its nests, which it commandeers, into Iberia. Little Swift has also become a breeding bird, as has the easily overlooked Plain Swift, previously only known from Maderia and the Canary Islands, with a small colony found in Portugal in 2019.
Trumpeter Finch, the sixth species that has broken out of Africa and become an Iberian breeder, is now found easily in south-eastern Spain, following the first breeding record in 1971.
Black-winged Kite is now easy to find in Iberia, but the first proven breeding records came from Portugal in 1944 and Spain as recently as 1975 (Lynn Griffiths).
Further down the line
Lesser Flamingo and Laughing Dove have both become regular in Iberia, with recent breeding records suggesting they could be next to successfully establish populations. 'Atlas Buzzard', currently recognised as a form of Long-legged Buzzard but recently found to be more closely related to Common Buzzard, started showing up regularly in 1990s, eventually leading to a number of breeding records on the north shore of the Strait of Gibraltar over the last 15 years. However, hybridisation has occurred with Common Buzzard in the area and the buzzards either side of the Strait may even represent a hybrid swarm.
There are plenty more possibilities, though, with Lanner Falcon (a former Iberian breeder), Cream-coloured Courser, Lesser Crested Tern, Common Bulbul and House Bunting all having made breeding attempts in Iberia in recent times.
House Bunting, which has recently nested in Spain, is likely to make more appearances and could even establish a population in Iberia (Glyn Sellors).
Other African species and forms that have occurred as vagrants with increasing frequency are currently less likely to develop breeding populations, though Moussier's Redstart, Pied Crow and Desert Wheatear are among those that could plausibly find suitable ground to breed.
As for species that haven't yet been recorded at all, Namaqua Dove is a prime contender for an Iberian firsts, for it is appearing ever more frequently in Morocco. Brown-throated Martin, which is now breeding within 100 km of the Spanish side of the Strait, is another one for birders in Iberia to swat up on, as is Atlas Pied Flycatcher..
As colonising species become established in new areas and face various pressures, conservationists need to deliver strategies to protect them effectively. On a wider scale, the documented range shifts highlight the urgency of addressing the climate crisis to manage its rapid effects on biodiversity.
While the drivers behind the vagrancy and establishment of African species are concerning, birders can also enjoy seeing and understanding these exciting birds in a European context.
Reference
Garcia, E. 2024. African Birds in Iberia: Recent Colonists, Potential Colonists and Vagrants. Ardeola. DOI: https://doi.org/10.13157/arla.71.2.2024.rp1
