A palaeornithological assemblage from the early Pliocene of the Mediterranean island of Mallorca: Raptorial birds as bioaccumulators at Na Burguesa-1

A palaeornithological assemblage from the early Pliocene of Mallorca (Balearic Islands) is documented on 583 fossil bones from Na Burguesa-1 site. Ten different taxa have been identified: two Tytonidae, one small-sized Strigidae, one Phasianidae, one Charadriiform, and at least five Passeriformes. The specimens included in the Tytonidae correspond to a giant Barn Owl, Tyto sp. 1, with size similar to Tyto robusta, and a second Barn Owl, Tyto sp. 2, similar in size to Tyto sanctialbani. The small-sized Strigidae is attributed to Otus sp., although some of the pedal phalanges obtained are included only tentatively in this genus. The presence of these nocturnal raptorial birds combined with the prevalence of small vertebrates (mainly ranging from ca. 8 g to almost 1 kg) with practically unaltered bones suggests that this deposit was originated by the accumulation of prey remains of these owls.