Family Swifts (Apodidae)

Data Deficient

Fernando Po Swift (Apus sladeniae)


French: Martinet de Fernando Po German: Westafrikasegler Spanish: Vencejo de Fernando Poo

Cypselus sladeniæ


, 1904,

Fishtown, Bioko


Closely related to A. bradfieldi, A. berliozi and A. pallidus. Has been considered conspecific with A. barbatus, A. apus and also with A. niansae and A. unicolor. Differs from geographically closest race serlei of A. barbatus (with which it was lumped in HBW) in its much-reduced amount of white on throat (2); glossy black of mantle with blue reflections vs glossy sooty black (2); more emarginate outer rectrix in barbatus (sensu lato)#R (1). While a total score of 5 is insufficient to establish the form unequivocally as a species under the criteria used herein, it is relatively high for a swift, and there remains the evidence of apparent or virtual sympatry with serlei#R, so that treatment as a full species pending further discoveries appears, on balance, the marginally better choice. Monotypic.

What do (1) and (2) mean? Learn more about the scoring system.

SE Nigeria, W Cameroon (Mt Kupe) and W Angola; possibly N Liberia. Old records from Bioko.

Descriptive notes

16 cm. Medium-sized, dark blackish-brown swift, which is overall even blacker than formerly conspecific A. barbatus and often lacks any greyish-white feathering on... read more


Not definitely known, but birds sound recorded at Mt Moco, Angola, gave “a short, high-pitched... read more


Primarily recorded over forest, and in montane regions.

Food and feeding

Diet and foraging behaviour unknown, although presumably similar to A. barbatus.


Nothing known, although the original series of specimens collected on Bioko were in breeding condition in late Dec and early Jan. In... read more


It has been suggested that species breeds on Bioko and visits the mainland during non-breeding... read more

Status and conservation

Not globally threatened. Currently considered to be Data Deficient. Very poorly known, with no estimates of population size. Known from Bakossi Mts, W Cameroon (single record... read more

Recommended citation

del Hoyo, J., Collar, N. & Kirwan, G.M. (2020). Fernando Po Swift (Apus sladeniae). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from on 30 March 2020).