Eleonora’s Falcons in Morocco imprison live birds to keep them fresh for a later meal. This behavior is unheard of before in the animal kingdom.
The Eleonora’s Falcon (Falco eleonorae) is mainly insectivorous outside the breeding season. During the nesting period, which is very late (from July to October) as an adaptation to coincide with autumnal bird migration, both adults and chicks consume mainly birds. These are mainly passerines and other small non-passerine birds like hoopoes and swifts that migrate through the Mediterranean islands and Atlantic coast.
In Morocco, there are two breeding colonies of Eleonora’s Falcon, both on the Atlantic coast. The first is located at Mogador islands, off Essaouira which is one of the the biggest in the world. The second is located in mainland cliffs at Bouknadel, north of Rabat/Salé.
During a fieldwork study in the framework of PIM-Initiative in 2014, Prof A. Qninba and his colleagues recorded an unusual predation behaviour by this falcon in the Mogador islands.
The authors remarked that Eleonora’s Falcons kept alive some of the captured prey. To do this, “the falcons keep or ‘imprison’ some preys in a relatively deep cavities or in rock fissures from where they can’t escape as their flight feathers were already plucked (example of the Common Chiffchaff below). The falcons also keep the small birds they catch trapped in a tight and deep holes which makes them unable to move neither their wings nor their hanging legs (photo 2 of the Common Whitethroat)”.
The authors reported also that this behaviour can occur even before the eggs hatch, and was already well known to a local fisherman who is staying in the islands in a more or less regular basis for decades.
The authors interpreted this hitherto unknown behaviour – for the Eleonora’s Falcon or any other raptor species – as a form of food storage behaviour. They wrote: “keeping prey alive, one or two days (the precise period not yet known), may allow the falcons to have a fresh food on the right moment, because the dead prey brought to the nest and untouched can no longer be consumed as it dries out too quickly”.
This unusual predation behaviour was described in this paper published in the last issue of the journal Alauda:
Qninba, A., Benhoussa, A. Radi, M., El Idrissi, A., Bousadik, H., Badaoui B. & El Agbani, M.A. 2015. Mode de prédation très particulier du Faucon d’Éléonore Falco eleonorae sur l’Archipel d’Essaouira (Maroc Atlantique). Alauda 83: 149-150.