The Social Organisation of the Dusky Moorhen, Gallinula tenebrosa Gould (Aves : Rallidae)

Abstract

A population of dusky moorhens was studied between October 1974 and December 1976. Moorhens were present in the study area throughout the year, existing predominantly in free-ranging flocks in May and June and tending to form territorial groups of from two to seven birds from July to April. In a group there were from one to three males per female; all males copulated with all females. Groups formed in July were predominantly of experienced adults and did not cease territoriality until April; those formed later, in September, were predominantly of immatures and tended to cease territoriality in March. The former had larger territories with more reeds, less sexual behaviour although more frequent successful coition, and a higher productivity than the latter. Productivity did not increase with group size although those with more than four birds lost twice as many eggs as smaller groups. It is unlikely that members of a group are related. The most frequent group size was four and it is postulated that groups of this size produce the most young. The skewed ratio in groups may result from the scarcity of nest sites, which limits the number of females per group.

Social relationships in a cooperatively polyandrous group of tamarins (Saguinus fuscicollis)

“…Koenig and Mumme's (1987) data show that males who share a female with one or two other males have higher fitness than do those who nest singly. In dusky moorhens (Gallinula tenebrosa) there is no evidence of dominance hierarchies among group members, all males copulate about equally frequently, and aggression among group members is rare (Garnett 1978(Garnett , 1980. In pukekos (Porphyrio porphyrio), male dominance hierarchies are evident and subordinate males are sometimes unable to complete copulations if dominant males are nearby.…”

The importance of the altricial – precocial spectrum for social complexity in mammals and birds – a review

“…(raven, jackdaw, rook, carrion crow ( Corvus corone ))[83, 100, 258, 260]BPGreylag goose; Bewick’s swan ( Cygnus bewickii ); Eider duck ( Somateria mollissima )[258, 261–264]Communal defenceMACrested black macaque ( Macaca nigra )[103]MPChamois ( Rupicapra rupicapra );[102]BAMontagu’s harrier ( Circus pygargus ); Sabine’s gull ( Xema sabini )[265, 266]BPWhite-fronted goose ( Anser albifrons )[267]Communal/Cooperative breedingMAvarious species - Review[107, 125, 268]MPvarious species – Review; e.g. Degu ( Octogon degus ); African striped mouse ( Rhabdomys pumilio )[105, 107, 110, 125, 268]BAvarious species - Review[104, 109, 269]BPvarious species – Review; White-winged trumpeter ( Psophia leucoptera ); Buff-throated partridge (Tetraophasis szechenyii); Black-breasted wood-quail ( Odontophorus leucolaemus ); Common moorhen ( Gallinula chloropus ); Dusky moorhen ( G. tenebrosa); pukeko ( Porphyrio melanotus )[104, 109, 120–123, 269–271]Conflict resolution ( e.g. reconciliation/consolation; redirected aggression)MAvarious Primates – Review; Wolf ( Canis lupus ); Spotted hyena; Meerkat ( Suricata suricatta )[74, 111, 115, 272–275]MPBottlenose dolphin ( Tursiops truncatus ); Horse;[…”

“…Cooperative breeding systems are more common in altricial (11% of 7698 species, including many passerines) than in precocial (4% of 789 species) birds [35, 104, 118]. This is presumably due to the extended need of parental care in altricial nestlings, offering the opportunity for subordinates to increase reproductive success of the breeders through helping ([36, 119], but see [120–123] for examples of cooperative breeding in precocial birds). Although there are several precocial bird species that breed cooperatively, there is a lack of information on their detailed social structure.…”

“…the white-winged trumpeters ( Psophia leucoptera) and dusky moorhen ( Gallinula tenebrosa ), indicate a polyandrous mating system [122–124]. The male-biased sex ratio in these groups is either due to defence of large permanent territories in order to supply sufficient resources [124], or limited numbers of nest sites [123], which created opportunities for cooperative breeding. In contrast, cooperative breeding in mammals is generally rare (<5% species; [125]) and where it does occur, cooperative breeding appears to be independent of the developmental mode [125].…”

Biología reproductiva de <i>Porphyriops melanops bogotensis</i> (Gruiformes, Rallidae) subespecie endémica y amenazada del norte de los Andes

“…Las poblaciones colombianas constituyen una subespecie endémica (P. m. bogotensis), aislada cerca de 3000 km de las más cercanas que se encuentran en Bolivia y Brasil (Taylor 1996). En Colombia, en donde se reproduce a lo largo de todo el año (Rosselli et al 2016), P. m. bogotensis se restringe a los humedales del altiplano Cundiboyacense entre los 2500 y 3100 m; estos ecosistemas han disminuido en más del 97 % y están altamente transformados, lo que ha llevado a que Garnett 1980, Kaufmann 1987, Eddleman et al 1988, McRae 1996, Jenkins 1999, Post y Seals 2000. En Suramérica, la información disponible para la mayoría de las especies es insuficiente para medidas efectivas de conservación (Taylor 1996).…”