Agonistic behaviour - Wattled jacana

The wattled jacana is the only resident bird with polyandrous habits in the reserve. In this unusual mating system the female forms a harem. She chooses up to five males with which she mates simultaneously and separately in the territory each male owns. The male, instead, mates only with that female and he is responsible for building the nest, incubating the eggs and caring for the young. This means that in this case polyandry is associated with parental role reversal. A typical feature of this type of system is that the female is bigger in size than the male.
Jacanas are territorial birds. The pair defend the territory from intruders or other jacanas, which compete for resources.
In a ritualized confrontation there is no physical aggression. It consists of a "dialogue" of displays triggered by gestures, visual and/or sound cues which give rise to action and reaction.
The photos in video format belong to the same conflict situation between a pair of jacana and an intruding jacana. On three occasions the intrude attacks and ends up by being expelled

06-08-06 © Roberto Ares
The intruder steps into the scene with vocalizations and menacing posture. The wings are somewhat separated from the body to show off the spurs. The territory holder responds to the attack likewise (threat display). Considering the male´s attitude the intruder breaks visual contact (appeasement), and crouches to fly away (escape). The female does not actively participate.
In the second attack the intruder repeats the threat, appeasement and escape displays. Nevertheless, a male´s cue makes the female get closer to take part in the conflict.
A brief communication between the pair and the male resumes the defence. A light skirmish is enough to drive the intruder away. The territory holder has reasserted his dominance over his territory.