Sort:
Open Access Research Article Issue
Bare-throated spurfowl (Pternistis spp.) males across Africa impress females with bright throat colours during courtship
Avian Research 2023, 14 (3): 100106
Published: 27 May 2023
Abstract PDF (2.2 MB) Collect
Downloads:17

The role of bare body parts in sexual signalling in birds has received relatively little attention. I describe how the bare-throated spurfowl males saturate the colours of their throats to attract females. Of the 23 Afrotropical spurfowl species, the bare-throated subgroup includes Yellow-necked Spurfowl (Pternistis leucosceptus), Red-necked Spurfowl (P. afer), Grey-breasted Spurfowl (P. rufopictus) and Swainson's Spurfowl (P. swainsonii). The rest of the species include fully feathered throated spurfowls. Throat colour intensity of bare throats was scored using an extensive online digital photographic archive encompassing the four species across the year's seasons. Each throat (n ​= ​836) was assigned to one of four colour-intensity categories to explore the relationship between colour intensities, breeding cycles, and environmental variation. Except for Swainson's Spurfowl male saturation of throat colours correlated with monthly rainfall, which peaks one or two months before egg laying. Swainson's Spurfowl peaks during egg laying. Yellow-necked Spurfowl has the largest bare throat. Bare-throated spurfowl males perform an elevated courtship display posture above the female to feature their throat colour. No such displays occur in feather-throated spurfowl. Males with low throat colour saturation harbour more ectoparasites on their bare throats than birds with saturated throats. Male Red-necked Spurfowls have significantly larger bare throats than females. The primary function of bare throats probably assists in thermoregulation, particularly in arid regions. The bare throat may have evolved a secondary role in mating. Yellow-necked, Red-necked, and Grey-breasted Spurfowls use their saturated throat colours as ornaments to court females during the breeding season. Unobtrusive female throat colours (unsaturated) may discourage male interlopers and predation during egg laying. Saturation appears to be carotenoid-food based. The different colours among the bare-throated species may serve as prezygotic mechanisms that inhibit cross-breeding and explain why females also have coloured throats.

Open Access Research Issue
The phylogeny of francolins (Francolinus, Dendroperdix, Peliperdix and Scleroptila)and spurfowls (Pternistis) based on chick plumage (Galliformes: Phasianidae)
Avian Research 2018, 9 (1): 2
Published: 08 January 2018
Abstract PDF (1.8 MB) Collect
Downloads:12
Background

This paper describes the chick plumage of spurfowl (Pternistis) and francolin (Francolinus, Dendroperdix, Peliperdix and Scleroptila) chicks, tests its signifcance for phylogenetic relationships and also explores the patterns of character evolution in the francolin and spurfowl lineages. Previously regarded as monophyletic, the two evolutionarily distant clades are now divided into fve genera. Questions considered were whether chick plumage supports the dichotomy between spurfowls and francolins and what role habitat matching plays.

Methods

The study was based mainly on photographs of chick skins from the American Museum of Natural History and the Natural History Museum at Tring. Eight plumage characters were selected for comparative scoring, summarised in a matrix. These characters were subsequently analysed phylogenetically and their evolution was traced on the existing molecular phylogeny using a parsimony approach.

Results

Based on chick plumage the phylogeny of species groups among francolins and spurfowls, was largely unresolved possibly ascribed to a high degree of symplesiomorphy inherent among the Phasianids. This possibly could have resulted in a high degree of polytomy particularly among the spurfowls and francolins. Furthermore, the ancestral state reconstructions revealed high prevalence of symplesiomorphic states and reversals which do not help in the classifcation of groups. Although the dierences are described that separate some African francolins from spurfowls, other francolins (in Asia and Africa) share remarkably similar characteristics with spurfowls. Plain dark dorsal plumage is probably advantageous for avoiding detection by predators in forests, while facial stripes optimise the breaking of body shapes in dense grass cover (as in Scleroptila spp.) and semistriped faces are advantageous for stationary camouage under tree and bush cover (as in Pternistis spp.).

Conclusions

Although symplesiomorphy is a hereditary explanation for downy colours and patterns, the traits relevant for habitat matching are combined in a manner which is determined (adaptation) by natural selection.

Open Access Research Issue
Orange River Francolins (Scleroptila levaillantoides) persist in fragmented Highveld farming landscapes, South Africa
Avian Research 2017, 8 (1): 11
Published: 12 May 2017
Abstract PDF (436.6 KB) Collect
Downloads:18
Background

How do Orange River Francolins (Scleroptila levaillantoides) adapt to an intensive farming landscape with grass (grazing) camps and crop cultivation? To answer this question, a study was carried out in south-east of Johannesburg in South Africa to clarify the interaction of francolins with a landscape consisting of land use mosaics.

Methods

A transect-road of 45 km was traversed weekly during November 2015–October 2016 through flat maize (Zea mays) and cattle (Bos primigenius) grazing fields. Francolins were counted in three land use mosaic types along the transect-road (including the road): grass camps on both sides of the road (grass/grass edges); arable fields on both sides (arable/arable edges) and arable land on one side with grass camps on the opposite side of the road (arable/ grass edges).

Results

Francolins used all three mosaic types, but the arable/arable edges were least frequented. Nonetheless, the arable/arable edges played an important part: francolins, including females with chicks, moved along the arable/arable edges, which enabled contact between sub-populations, and the arable/arable edges provided temporary cover (e.g. stubble and maize plants) and ploughed firebreaks to forage (e.g. for bulbs).

Conclusion

Cultivation of crop within grasslands does not constrain breeding, movement and habitat use by the Orange River Francolin. For conservation purposes it is critical that the fine-scale mosaic of grazing and cultivation areas remain intact.

Open Access Research Issue
Vocal behavior of Crested Guineafowl (Guttera edouardi) based on visual and sound playback surveys in the Umhlanga Lagoon Nature Reserve, KwaZulu-Natal province, South Africa
Avian Research 2015, 6 (1): 13
Published: 21 July 2015
Abstract PDF (1.2 MB) Collect
Downloads:12
Background

Generally speaking, playbacks were often ineffective to determine the group sizes of birds since mainly males from leks responded. This limitation has not been tested properly for flocking birds such as Crested Guineafowl (Guttera edouardi) with the view to use it as a counting method. The Aims of the study reported in this paper were (1) to describe the calls of Crested Guineafowl in a social context; (2) to interpret calls in an evolutionary context; and (3) to demonstrate that playbacks can be used to locate and count Crested Guineafowl in small isolated forests.

Methods

The vocal behavior of Crested Guineafowl was observed during a survey conducted in the Umhlanga Lagoon Nature Reserve (KwaZulu-Natal, South Africa) from November 2010 to June 2012. Transect line observations and sound playback Methods were used.

Results

The behavioral context and structure of calls were described. The eight calls described for Crested Guineafowl were produced mainly to unite flock members in the dense understory, where visibility was poor, and to repel intruders. When not disturbed, Crested Guineafowl were quiet and only made soft contact calls.

Conclusions

The high rate of call back and the fact that flocks invariably approach the source of the call en masse, shows that field researchers are able to assess the population size of Crested Guineafowl with sound playbacks along a transect. The value of playbacks as a conservation tool is assessed.

Open Access Research Article Issue
Population structure and mating system of the Red-crested Korhaan (Lophotis ruficrista) in South Africa
Avian Research 2014, 5 (1): 9
Published: 24 December 2014
Abstract PDF (361.3 KB) Collect
Downloads:11
Background

The mating system of the korhaans and bustards in southern Africa is either based on polygyny or monogamy. The Red-crested Korhaan (Lophotis ruficrista) has been described as polygynous but otherwise very little is known about its breeding biology. The aims were to describe the population structure and male behavior during breeding.

Methods

The data collected for this paper was mainly based on field transect surveys carried out in 2009, 2010 and 2011. The population structure of the Red-crested Korhaan in the temperate Borakalalo Game Reserve (BGR) was compared with that in the arid Molopo Nature Reserve (MNR) (both situated in the North West province of South Africa). The study was mainly conducted in the BGR but additional work was conducted in the MNR for comparison.

Results

The difference in mean group sizes between MNR (1.03) and BGR (1.07) was statistically not significant. Group sizes were not affected by climate despite the fact that the BGR received about 650 mm precipitation per annum and the MNR about 200 mm. In both reserves the apparent sex ratios were skewed in favor of males (1:0.29 in the BGR and 1:0.1 in the MNR). The population was dispersed in a clumped manner which is ascribed to the formation of leks. Leks were positioned in open habitat while females invariably concealed themselves under cover.

Conclusions

The leks formed the pivot of the mating system of the Red-crested Korhaan and are identifiable social structures that field ecologists can use to monitor population stability.

Total 5