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Introduction

A diagnosis and an identification of a species or any other recognized taxon imply two distinct things. Essentially, the ability to identify a species is the ability to recognize individuals in the field, whether they are at Brakfontein Private Nature Reserve, Wesselsbron in the Free State or in the Melmoth area, KwaZulu-Natal, and to say what species they belong to.

But diagnosing a species involves analysis of characters, whereby a person singles out characteristics that set a group or groups of individuals or populations of a species apart from other closely related species.

These methodological approaches are crucial and ought to be used in both lab and field settings. Unfortunately, applying these ideas can drive some people insanely confused and upset, to the point when they even pull out their hair!

A constant dialogue is necessary for ornithologists, particularly taxonomists, to accurately diagnose bird families, genera and species—especially in light of the enormous advancements in the genetic science over the past century. Having stated that, let’s take a closer look at the various taxonomic levels in an effort to clear up any confusion and, eventually, save people’s hair!!

A species—with birds being the main focus of the present essay—is the fundamental unit of biological taxonomy, which comprises individuals that are morphologically unique and resemble each other more than members of any other group. Usually, a relatively large number of individuals make up a species. Additionally, populations within a species are usually genetically stable, freely interbreed wherever they come into contact, produce viable offspring, and never (or only rarely) interbreed with members of other species.

A subspecies (race, population) is a taxon that describes physically distinct (identifiable) and genetically stable populations within a particular species, or bird populations within a geographical area that differ from the originally described in some ways (such as plumage, length of various morphological structures, or coloration), but not enough to be classified as a distinct species. Along limited areas of interaction, subspecies may interbreed, thus altering the genetic composition of the subspecies and ultimately the species.

A taxonomic or classification category known as a genus refers to a species or a group of related species that are thought to resemble one another more than any species in other genera. The avian genus Lagonosticta is quite challenging in this regard.

Lagonosticta birds are small, colourfully patterned granivores of the Old World, also known as firefinches, with conical and stout bills. Both sexes often have small white dots or bars on the sides of the breast and/or belly, along with a considerable amount of red in their plumage. These birds belong to the same family Estrildidae, as do firetails, waxbills, mannikins, avadavats, grassfinches, twinspots, and parrot-finches.

The name Lagonosticta is derived from the Greek words lagōn, which means ‘flank’, and stiktos, which means ‘spotted’. The flamboyant reddish-pink to crimson-red colour of their bodies and spots on their belly and breast sides are then used to diagnose the group.

This appears to be quite simple, but there are a few contradictions. Lavender Waxbills (Estrilda) have a similar body colour, flank spot pattern, and distribution of spots, while Firetailed Finches (Emblema) and Painted Finches (Emblema picta) have boldly spotted flanks along with a significant amount of finely cross-barred plumage.

Certain individuals within a genus or species may have markings solely on the front of their breast and/or belly, on both flanks of the breast and/or belly, or they may have no markings at all (Fig. 1). Some birds have a darker or browner hue than red. All these differences and similarities can be quite confusing sometimes and can be largely attributed to genetic variation.

Figure 1: Firefinches lying on their backs and showing the bills and the presence or absence of the white spots on the breast and/or belly: (A, B) male and female Red-billed Firefinch (Lagonosticta senegala rendalli), (C) male Jameson’s Firefinch (Lagonosticta rhodopareia jamesoni), (D) male African Firefinch (Lagonosticta rubricata rubricata), from the museum collection.

When forming groups, gene flow between interbreeding individuals should always be taken into account. Gene flow is defined as the movement of the genetic material into or from a population as the result of the reproductive contact between individuals.

According to Goodwin (1982), the bright red ancestral forms might have carried evolutionary traits in their genetic pool related to the flaming colour of the body and the markings on the belly, breast and sides. Given that these characters are similar, the question that needs to be answered is: How may similar characters be classified as diagnostic? Because it is evident that there is a gene pattern that is either slightly altered or preserved through lineage and subsequent generations.

Morphology of Firefinches

Firefinches have robust, conical bills that appear in a range of colours. The colour of the bill (upper and lower mandibles) is coded by certain genes. The bill may be one solid colour, or blended with another colour to give the impression that it is bicoloured (Table 1).

Figure 2: The African Firefinch Lagonosticta rubricata rubricata from the museum’s bird hall, with labelled morphological features.

The upper mandible of the Red-billed Firefinch has a thick longitudinal line that extends from the posterior base to the anterior tip, whereas the lower mandible has a somewhat thinner longitudinal line from the posterior base to the anterior tip. When the bird is still alive, the upper and lower mandibles are both red. After the bird is skinned and stored for a long time, the colour changes to creamy white (Figs 1A and 1B).

While the majority of Jameson’s firefinches have a completely solid upper mandible, some birds have light-coloured posterior bases. In some instances, the lower mandible has a shorter and thinner longitudinal line and is less solid. Its posterior base has a lighter patch (Fig. 1C).

The upper mandible of the African Firefinch is solid and dark, while the posterior base of the lower mandible has a lighter patch, more prominent on the ventral side (Fig. 1D).

Table 1: The males of the Red-billed (Lagonosticta senegala rendalli), Jameson’s (Lagonosticta rhodopareia jamesoni) and African (Lagonosticta rubricata rubricata) firefinches, with detailed differences and similarities.

The strength and colour of the feathers on adult birds differ from those on immatures. A bird that is yet to grow into its adult plumage but has had its first moult from juvenile plumage is considered immature. An inexperienced eye may not always be able to see this, but a discerning gaze notices it.

Firefinches moult or replace old feathers once a year. Individuals with worn-out feathers appear much browner or duller. Those that are fresh from the moult may be significantly brighter. This observation may be slightly biased since the females are predominantly brown. To the untrained person, this could be one of the elements creating confusion.

The most worn-out regions of feathers are those that are exposed to their immediate environment, getting scratched by objects such as trees and pebbles. The red colour of the Red-billed, Jameson’s and African firefinches is typically limited to the tips and fringes of the feathers (on barbs and barbules). When worn-out, the colour may become more pink or brown rather than red; however, this is mostly true for red, crimson or vibrant hues. The brown species or individuals typically turn dull.

The white hue on the feathers results from the coloration of two barbs at a time; however, up to six barbs can be coloured. Both the anterior and posterior barbules are white.

Variation

Males of Lagonosticta senegala rendalli have redder upperparts and warm brown plumage overall. The female is similar to the male, but duller (Table 2). White spots on the breast are common in both sexes, often covering the entire breast (Fig. 2) (Clement et al. 1993).

The male of Lagonosticta rubricata jamesoni is red. The majority of the upper and lower regions are pinkish-red with a hint of brown. The female is similar to L. s. rendalli, but with a softer colour. Males have fewer white dots on their flanks than females do.

African Firefinch males (Lagonosticta rubricata rubricata) have reddish-grey top portions and reddish-black underparts. Females are similar to males, but duller. Males have fewer white markings on their flanks than females.

Table 2: The females of the Red-billed (Lagonosticta senegala rendalli), Jameson’s (Lagonosticta rhodopareia jamesoni) and African (Lagonosticta rubricata rubricata) firefinches, with detailed differences and similarities.

The male Jameson’s and African firefinches have more black feathers than brown feathers, whereas the male Red-billed Firefinch has more brown feathers than black. The female Jameson’s and African firefinches have more grey feathers than brown feathers; however, the female Red-billed Firefinch has more brown feathers than grey ones; this is also true for newly moulted individuals. These variations are mostly the result of gene flow; a gene bank would be extremely useful for proper understanding and distinguishing between the subspecies and species.

Distribution

The Red-billed Firefinch (Lagonosticta senegala rendalli) is distributed in Angola, Zambia, Zaire, Malawi, Tanzania, Mozambique and South Africa. The range of this species in South Africa is largely limited to the northern parts of the country, including Hoopstad, Bothaville, Wesselsbron and also in most parts of the Free State.

The Jameson’s Firefinch (Lagonosticta rhodopareia jamesoni) is found in Kenya, Tanzania, Malawi, Zambia, Namibia, Zimbabwe, Botswana, Mozambique and South Africa. It is distributed throughout South Africa’s northern provinces, including Parys, Wesselsbron, Vredefort areas and in the central parts of the Free State. The Jameson’s Firefinch has recently extended its range southward to the Soetdoring Nature Reserve and areas along the Modder River. Its host, the Purple Indigobird, is following suit (Brooks et al. 2022; Sabap2 2024).

The African Firefinch (Lagonosticta rubricata rubricata) is found in Senegal, Ethiopia, Mozambique and eastern South Africa. Its distribution in South Africa is primarily limited to Limpopo, Mpumalanga, KwaZulu-Natal and areas along the east coast to as far as Gqeberha [Port Elizabeth].

Conclusion

Whether you are an expert, an occasional birder or a beginner, recognizing and diagnosing firefinches will inevitably confound you. It will happen, and the only way to avoid getting confused and emotionally drained is to look at firefinches with an open heart. Remember that it is not only red and pink or black and brown; there is also a grey area.

References

Brooks, M., Rose, S., Altwegg, R., Lee, A.T.K., Nel, H., Ottosson, U., Retief, E., Reynolds, C., Ryan, P.G., Shema, S., Tende, T., Underhill, L.G. & Thomson, R.L. 2022. The African Bird Atlas Project: a description of the project and BirdMap data-collection protocol. Ostrich 93(4): 223-232. https://doi.org/10.2989/00306525.2022.2125097

Chittenden, H., Allan, D. & Weiersbye, I. 2012. Roberts geographic variation of southern African birds: A guide to the plumage variation of 613 bird races in southern Africa. Cape Town: John Voelcker Bird Book Fund. 284 pp.

Cillié, B., Cillié, N., Penlington, P., Hardaker, T. & Wiesler, K. 2022. Veld: Birds of southern Africa: The complete photographic guide. Pretoria: Game Park Publishing. 560 pp.

Clement, P., Harris, A. & Davis, J. 1993. Finches & sparrows: An identification guide. Christopher Helm. 500 pp.

De Swardt, D.H. 1996. Jameson’s firefinch Lagonosticta rhodopareia along the Vaal River, Free State Province. Mirafra 13: 67-68.

Goodwin, D. 1982. Estrildid finches of the world. London: British Museum. 328 pp.

Harrison, J.A., Allan, D.G., Underhill, L.G., Herremans, M., Tree, A.J., Parker, V. & Brown, C.J. (Eds) 1997. The atlas of southern African birds. Volume 2: Passerines. Johannesburg: Birdlife South Africa. 732 pp.

Hinze, I. 2001. The Firefinches: Genus Lagonosticta. Waxbills and their Allies, Part VI. AFA Watchbird 28(4): 44-48. https://watchbird-ojs-tamu.tdl.org/watchbird/article/view/3374

Hockey, P., Dean, W.R.J. & Ryan, P.G. 2005. Roberts birds of southern Africa. 7th ed. Cape Town: Trustees of the J. Voelcker Bird Book Fund. 1296 pp.

SABAP2. 2024 Southern African Bird Atlas Project 2. https://sabap2.birdmap.africa (accessed 25 March 2024).

Sinclair, I., Hockey, P., Tarboton, W., Perrins, N., Rollinson, D. & Ryan, P. 2020. Sasol birds of Southern Africa. 5th ed. Cape Town: Struik Nature. 488 pp.

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