Vocalizations of European Honey Buzzards (Pernis apivorus) in Southern Africa

Abstract

Contrary to some sources, the European Honey Buzzard is not silent in Africa. This study documents 51 records of the species vocalizing on the continent. Vocalizations were given by birds apparently encountered alone (n=30) and when accompanied by another European Honey Buzzard (n=22). Where age was known, 11 calling birds were adults and ten were juveniles. Where details were available, most calls were given by birds in flight (n=30), with 11 from perched birds and two from birds heard calling while both in flight and perched. In most cases the sex of the bird was not recorded (n=42) and young birds (first- and second-years) are difficult to sex with certainty; of the remainder, two were males and nine were females. Most calls were the typical flight call of the species (n=43), with apparent alarm calls (n=7) the next most frequent call type. Most calls were delivered in flight (n=31), 19 by single birds and 12 by two birds together in flight. The calling by two birds was associated with flight displays similar to those described on the breeding grounds and occurred especially in late summer (December onwards; 25/40 records). A relatively high proportion of calls occurred during interactions between two European Honey Buzzards (n=18). Calling associated with two birds together and accompanied by aerial displays has not been described in Africa before, and is suggestive of either early pairing of the adult birds prior to migration or breeding activity locally in Africa. Vocalizations between young birds though may be more social as opposed to sexual in nature. The large (5X) increase in records of European Honey Buzzards in South Africa in recent years likely increases the chances of conspecific interaction. It also raises the possibility of breeding, especially in more-temperate South Africa.