Helping opportunities and space segregation in cooperatively breeding cichlids

Studies of cooperative breeding have largely ignored the role of conflict among helpers and how it shapes group dynamics and helping behavior. In the present study, performing laboratory experiments with cooperatively breeding cichlids from Lake Tanganyika, we show that secondary group members (potential helpers) occupy home ranges within the group territory and may be aggressive to one another. Experimental removal of secondary group members allowed the individual next in rank to move closer to the removed individual's home range. In the field, dominant secondary group members stayed closer to the brood chamber than did subordinate group members of similar size, and proximity to the brood chamber was related to the length of time spent inside. We suggest that space segregation and competition among secondary group members is common in these cichlids, and may limit the opportunities to provide help.