THE BREEDING BEHAVIOUR OF THE RED‐FOOTED BOOBY SULA SULA

• Published in: Ibis
• Main Author: NELSON, J. B.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1969
• Subjects: Galapagos; Tower Island; North Atlantic
• Online Access: http://dx.doi.org/10.1111/j.1474-919x.1969.tb02550.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1474-919X.1969.tb02550.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1474-919X.1969.tb02550.x

Summary. The breeding behaviour of the Red‐footed Booby on Tower Island, Galapagos, is described. A connection is traced between the arboreal nesting habit and the type and degree of ritualised behaviour; in general territories are large, movement relatively restricted, and territorial and intra ‐pair displays relatively few and undifferentiated when compared, for example, with the North Atlantic Gannet, in which the opposite conditions (dense nesting and maximal inter‐ and intra‐pair contacts) occur. On Tower Island, 96% of the Red‐footed Boobies are either brown or partly brown forms and 4% are full white forms. The adaptive significance of the polymorphism is discussed, and it is tentatively suggested that the brown form may be more nocturnal than the white. The average nest density was 0–009 pairs and the maximum density 0'053 pairs per square yard. Behaviour is considered under the headings: non‐display behaviour (sunning, sleeping, etc.); behaviour with some signal value (Feather Ruffing, Wing Flicking, etc.); behaviour concerned with site establishment (fighting, agonistic displays); pair relationship (mutual displays); incubation and parental care and behaviour of the chick. Before flying from their territory Red‐foots Wing Flick, a signal action which they have developed to a greater extent than other sulids. Other ritualised wing movements are rarer, possibly because they are associated largely with locomotion preceding flight, which is impracticable for the arboreal Red‐foot. Sideways Headshaking, a frequent dirt‐dispelling movement in the Gannet, is much reduced in the Red‐foot. Correspondingly, it is much less used in Red‐foot displays, whereas the Gannet incorporates it into many. Territorial fighting is relatively rare. Territorial behaviour includes Flight Circuiting over the breeding area, Wing Flailing, Jabbing, non‐ritualised Menacing and Forward Head Waving (a ritualised, aggressive, site‐ownership display). Appeasement displays are poorly developed, being confined in the adult to a fleeting ...