Robin Species Research Articles

Diversification of Petroica robins across the Australo-Pacific region: first insights into the phylogenetic affinities of New Guinea’s highland robin species

ABSTRACT Complex spatial and temporal phylogenetic patterns have emerged among Pacific Island radiations and their Australian and New Guinean congeners. We explore the diversification of Australo-Pacific Petroica robins using the first phylogeny with complete species-level sampling of the genus. In doing so we provide the first assessment of the phylogenetic affinities of two poorly known species with highly restricted ranges in the highlands of New Guinea – Subalpine Robin (Petroica bivittata) and Snow Mountain Robin (P. archboldi). Our analyses suggest that Petroica underwent an initial diversification during the Plio-Pleistocene that established four major lineages restricted to New Zealand (four species), Australia (four species), New Guinea (two species) and Pacific Islands + Australia (three or four species). All lineages appear to have undergone species diversification in situ with the exception of the Pacific Islands + Australia lineage where long-distance over-water dispersal must be invoked to explain the placement of the Red-capped Robin (P. goodenovii) within the iconic Pacific robin species complex (P. multicolor + pusilla). Two scenarios fit this biogeographic pattern: (1) a single ‘upstream’ colonisation of mainland Australia from a Pacific Island ancestor resulting in P. goodenovii, or (2) two or three ‘downstream’ colonisations from a mainland Australian or New Guinean ancestor resulting in the distinct Pacific robin lineages that occur in the south-west Pacific. Overall, biogeographic patterns in Petroica suggest that long-distance dispersal and island colonisations have been rare events in this group, which contrasts with other Australo-Pacific radiations that show evidence for repeated long-distance dispersals and multiple instances of secondary sympatry on islands across the Pacific.

Strong asymmetric interspecific aggression between two sympatric New Guinean robins

Interspecific aggression is predicted to be common in diverse tropical avifaunas but is seldom tested experimentally. I conducted two playback experiments to measure interspecific aggression between two sympatric Australo‐Papuan robin species that inhabit the understorey of montane New Guinean forests: Slaty Robin Peneothello cyanus and Ashy Robin Heteromyias albispecularis. The first experiment, at a location where both species were present, demonstrated strong asymmetric interspecific aggression; the larger Ashy Robin responded as aggressively to Slaty Robin playback as to conspecific playback, but Slaty Robins did not respond to Ashy Robin playback. In contrast, in the second experiment, which took place at a nearby site where Slaty Robins were absent, Ashy Robins did not respond aggressively to Slaty Robin playback. Thus, Ashy Robin interspecific aggression appears to be a learned response to the presence of Slaty Robins, and may reflect resource competition between these two sympatric species.

Distribution and feeding habits of three sea robin species (Bellator brachychir, Prionotus nudigula and Prionotus punctatus) in the Campos Basin, southeastern Brazil

The distribution, size structure, and feeding of three sea robin species belonging to the family Triglidae ( Bellator brachychir , Prionotus nudigula and Prionotus punctatus ) were studied based on specimens caught with bottom trawls on the continental shelf of Campos Basin, southeastern Brazil. The two Prionotus species were more concentrated in the inner shelf (<50 m), while B. brachychir was generally more abundant on the outer shelf (50-100 m). In general, the three species showed a carcinophagous diet, but with small overlap in their main preys. While amphipods was the most important prey to B. brachychir , isopods and shrimps were the basic food item found in P. nudigula and P. punctatus diet, respectively. This reduction in interspecific competition for food was followed by some degree of spatial segregation and thermal preferences for each species.

New species of robin found in Gabon

New species of robin found in Gabon

The role of intense nest predation in the decline of Scarlet Robins and Eastern Yellow Robins in remnant woodland near Armidale, New South Wales

A study of open-nesting Eastern Yellow Robins Eopsaltria australis and Scarlet Robins Petroica multicolor, on the New England Tablelands of New South Wales in 2000?02, found low breeding success typical of eucalypt woodland birds. The role of intense nest predation in the loss of birds from woodland fragments was investigated by means of predator-exclusion cages at robin nests, culling of Pied Currawongs Strepera graculina, and monitoring of fledging and recruitment in the robins. Nest-cages significantly improved nest success (86% vs 20%) and fledging rate (1.6 vs 0.3 fledglings per attempt) for both robin species combined (n = 7 caged, 20 uncaged). For both robin species combined, culling of currawongs produced a twofold difference in nest success (33% vs 14%), a higher fledging rate (0.5 vs 0.3 per attempt), and a five-day difference in mean nest survival (18 vs 13 days) (n = 62 nests), although sample sizes for nests in the cull treatment (n = 18) were small and nest predation continued. Although the robin breeding population had not increased one year after the cull, the pool of Yellow Robin recruits in 2001?03, after enhanced fledging success, produced two emigrants to a patch where Yellow Robins had become extinct. Management to assist the conservation of open-nesting woodland birds should address control of currawongs.

Vocal mimicry in African Cossypha robin chats

Four hypotheses were tested for explaining interspecific mimicry observed in AfricanCossypha robin-chats. (1) The five robin species imitate similar models. (2) Natal Robin imitations reflect the acoustic environment within their habitat. (3) Natal Robins imitate competitor species. (4) Natal Robins imitate predators and brood parasites. The study included analysis of extensive collections of sound recording of these five species, as well as recordings of the Natal RobinCossypha natalensis obtained in the field. The robin species mimicked different species groups, in accordance with their acoustic environment. This also applied to different Natal Robin populations. Only hypothesis (2) was confirmed, the others being refuted. It appears that bird species with simple calls have a greater probability of being mimicked. Our results were consistent with Hartshorne’s prediction that song versatility increases with song duration.

Is the black robin in genetic peril?

In 1980 the entire black robin species Petroica traversi comprised only five birds, and the current population of ≊ 200 individuals is known to be derived from a single breeding pair. We show here that levels of minisatellite DNA variation in the black robin are among the lowest reported for any avian species in the wild. Surprisingly, similarly bottlenecked control populations of a closely related species (P. australis australis) exhibit significantly higher levels of genetic variation. This suggests that the black robin's persistence in a single small population for the last 100 years, rather than the recent bottleneck itself, accounts for the low genetic variation observed. Despite apparent genetic impoverishment, survival and reproductive performance indicate that the black robin is viable under existing conditions. This example illustrates that significant levels of genetic variation are not a necessary prerequisite for endangered species' survival.

Habitat use and foraging behaviour of the scarlet robin and the flame robin at a site of breeding-season sympatry

The habitat selection and foraging ecology of scarlet robins (Petroica multicolor) and flame robins (Petroica phoenicea) were observed for three years at a site of breeding-season sympatry in order to examine seasonal patterns of foraging behaviour, habitat and resource use, and the significance of competition for food as a cause of interspecific aggression. Both species occupied habitats with open ground layers of grass or bark, and a sparse shrub-and-sapling layer. Flame robins occupied more mesic habitats; scarlet robins occurred in drier habitats. Seven habitat variables provided 73% separation between habitats occupied by the two species of robin. Both species foraged mostly on the ground during the cooler months. In summer and autumn, scarlet robins became snatchers of arthropods from bark and foliage substrates, and flame robins hawked for flying insects close to the ground. High overlap between their use of available foraging space, especially vertical foraging space, probably caused interspecific competition for food and space, leading to interspecific aggression and territorial behaviour. Such competition, in conjunction with the flame robin's interspecific dominance and apparently greater resilience to practices such as timber harvesting, may cause long-term changes to the distribution and relative abundance of each species. Recommendations for habitat management are considered briefly.

The Nesting Ecology of Sympatric Scarlet RobinPetroica multicolorand Flame RobinP. phoeniceaPopulations in Open Eucalypt Forest

Robinson, D. (1990). The nesting ecology of sympatric Scarlet Robin Petroica multicolor and Flame Robin P. phoenicea populations in open eucalypt forest. Emu 90, 40–52.This paper compares the nesti...

Interspecific Aggression and Territorial Behaviour Between Scarlet Robin Petroica multicolor and Flame Robin P. phoenicea

SummaryRobinson, D. (1989). Interspecific aggression and territorial behaviour between Scarlet Robin Petroica multicolor and Flame Robin P. phoenicea. Emu 89, 93–101.Scarlet Robins and Flame Robins defended mutually exclusive territories against one another at a site in south-eastern New South Wales. Playback experiments indicated that each species distinguished the song of the other species from a control species' song. Playback experiments further showed that each species responded most intensely to playback of conspecific song, less intensely to playback of the other robin species' song and hardly at all to the control species' song. When Flame Robins first arrived at the study site from their wintering grounds they were initially dominant to Scarlet Robins and established territories within Scarlet Robins' winter territories. Once interspecific territory boundaries had been established, the outcome of disputes was decided by the ownership status of contestants rather than species' status. Interspecific territoriality between Scarlet and Flame Robins may be a recent phenomenon resulting from changes to the forest environment such that both species have come into contact. One or other species may also have expanded its range in recent years. Interspecific aggression was perhaps stimulated initially by mistaken identification of sympatric species of robin, but now appears to continue because of interspecific competition for food and foraging space. It is envisaged that interspecific territorial behaviour will occur wherever Scarlet and Flame Robins come into contact during their breeding seasons.