Vie et milieu - Life and environment, 2018, 68 (1): 25-31

New insights into the morphology and of the baeticatus / scirpaceus complex based on a newly found West African syntopic population

M. Pavia 1*, A. Galimberti 2, I. Pellegrino 3, F. Silvano 4, D. Zuccon 5, G. Boano 6 1 Museo di Geologia e Paleontologia, Dipartimento Scienze della Terra, Università degli Studi di Torino, Via Valperga Caluso 35, I-10125, Torino, Italy 2 Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, P.za della Scienza 2, 20126-I, Milano, Italy 3 Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale, Viale T. Michel 11, 15121 Alessandria, Italy 4 Museo Civico di Storia Naturale, Via Aldo Fossati 2, I-15060 Stazzano (AL), Italy 5 Institut de Systématique, Evolution, Biodiversité UMR7205 CNRS MNHN UPMC EPHE, Sorbonne Université, Muséum national d’Histoire naturelle, CP 51, 57 rue Cuvier, F-75231 Paris Cedex 05, France 6 Museo Civico di Storia Naturale, Via San Francesco di Sales 188, I-10022, Carmagnola (TO), Italy * Corresponding author: [email protected]

REED WARBLERS ABSTRACT. – A precise knowledge on biodiversity in tropical developing countries is pivotal BURKINA FASO WING FORMULA to address proper conservation guidelines and policies, especially when natural habitats are IDENTIFICATION strongly jeopardized by land use changes due to agriculture or industrial issues. In West , DNA BARCODING Burkina Faso is a typical example of this emerging trend, and its natural or semi-natural wetland areas are of great importance as breeding or wintering sites for many species, includ- ing the taxonomic complex group of unstreaked reed warblers (genus Acrocephalus). The use of morphological characters to distinguish between A. baeticatus and A. scirpaceus occurring in syntopy, is often subtle. To shed more light on the taxonomic status of a newly found Acroceph- alus community in South Burkina Faso and on the reliability of the available criteria adopted to identify members of this species complex, we here compared the morphological features of some specimens collected during different field expeditions and supported our phenotypical assessment with a molecular identification approach. Sixteen Acrocephalus specimens were collected at a recent wetland area located South of Burkina Faso during winter. Specimens were measured and assigned to the species level based on the published and conventionally adopted morphological criteria. A COI-based DNA barcoding approach was used to confirm identifica- tion. Our integrated identification approach confirmed the occurrence of the first population of A. baeticatus for Burkina Faso. It is geographically isolated from other West African known populations. Interestingly, our results highlighted that the traditionally adopted identification trait, based on the emargination on the 7th primary, is not always valid to distinguish A. baetica- tus from its conspecifics, which also partly overlap in biometric measurements. We therefore support the greater reliability of the ‘wing length / P9 notch’ criterion recently proposed for the identification of Palaearctic unstreaked Acrocephalus species and its importance to separate the wintering species of Palearctic origin from the African resident ones.

INTRODUCTION and to assess the conservation status of populations at those sites. An emerging issue, shared by many tropical develop- During the ornithological surveys conducted in the ing countries, is the unsustainable trade-off between rapid Cascade Region, Southern Burkina Faso in 2003, 2010, human population growth and the need for preserving 2011 and 2012 (Pavia et al. 2012), a great monitoring and natural habitats and their biodiversity. In this framework, sampling effort was employed to increase knowledge on rapid changes in land-use, due to the inexorable spread diversity and ecology of the bird populations inhabiting of agriculture and exploiting of natural resources consti- the reedmace Typha beds surrounding the Lemorodou- tute the major threats to priority sites for avian conserva- gou Lake, located a few kilometers North to the city of tion in Africa (Söderström et al. 2003). Such a scenario is Banfora (Fig. 1). Around Banfora there are several lakes particularly evident in Burkina Faso, West Africa, where and marshes, many of them surrounded by reeds and 90 % of the population base its livelihood on agriculture other riparian vegetation. They are of artificial origin or and husbandry (Lungren et al. 2001). Scientific highly modified to create water reservoirs for agricultur- research is therefore pivotal for monitoring bird diversity al issues, particularly the sugar cane fields, which are of 26 M. PAVIA, A. GALIMBERTI, I. PELLEGRINO, F. SILVANO, D. ZUCCON, G. BOANO

non-desert areas of South and East Africa and with scat- tered and probably underestimated populations in Western Africa (Fry et al. 2000). The taxonomy and systematics of this species is also ambiguous. In fact, many authors con- sider A. baeticatus a valid and polytypic species with at least four recognized (Fry et al. 2000, del Hoyo et al. 2006, Kennerly & Pearson 2010). Other authors pointed out the extreme similarity between the song of A. baeticatus and European Reed Warbler (A. scirpaceus) (Dowsett-Lemaire & Dowsett 1987), thus advocating for the occurrence of only one species, A. scirpaceus, and considering A. baeticatus one of its African subspecies. The recently discovered North-African populations of reed warbler shows intermediate characteristics between Fig. 1. – Map of the Burkina Faso with the position of Banfora Southern populations of A. scirpaceus and A. baeticatus and of the Lemorodougou Lake (red star). guiersi (Amezian et al. 2010). Furthermore, the results of the genetic analyses (Leisler et al. 1997, Helbig & Seibold great extension. The permanent wetlands in sub-Saharian 1999) showed very close relationship between A. baetica- Africa are of crucial importance as wintering or stopover tus guiersi, and A. s. scirpaceus. More recently, the vari- sites for Palaearctic migrants (Wymenga & Zwarts 2010, ous subspecies of A. baeticatus have been considered as Alemayehu et al. 2017), and to support local populations conspecific of the European A. scirpaceus, on the basis of African species (Pavia et al. 2012). Among the various of the weak genetic, morphological, and vocal differenc- detected species (Pavia et al. 2012), we documented for es (Dickinson & Christidis 2014, del Hoyo et al. 2016), the very first time in this geographical region the presence also following the most conservative approach proposed of the African Reed Warbler Acrocephalus baeticatus by Olsson et al. (2016). Based on the more recent knowl- (Passeriformes: Sylvidae) (Pavia et al. 2012, Borrow & edge, we think that a thorough taxonomic revision using Demey 2014). integrated approach with both genetic and morphology is African Reed Warbler is a sedentary or short distance needed to verify the real distribution and potential areal migratory species of Acrocephalus widely distributed in overlapping of the various Reed Warbler taxa.

Table I. – Morphometrical and morphological features of African Reed Warblers Acrocephalus baeticatus (ACRBAE) and European Reed Warblers A. scirpaceus (ACRSCI) from the Lemorodougou Lake (SW) Burkina Faso. The specimens are codified with their MCCI catalogue numbers and GenBank accession numbers of the obtained COI DNA barcoding sequences are also provided. Mea- surements were taken according to Svensson (1992), Kennerly & Pearsons (2010), Deutsche Ornithologen-Gesellschaft (2011). The length (NL) and relative position (NP) of the notch of the 9th primary feather were measured following Malmhagen et al. (2013). Pri- mary feathers are numbered descendantly. TRS: Tarsus length, WGT: weight, E: emargination, W: Wing point, 2: position of the tip of P2 (P9 descendent) in relation to the tips of the other primaries (sensu Svensson 1992). Species Sex MCCI GenBank a.n. Wing P8 Bill Tail TRS WGT NL NP E W 2 ACRBAE F 3259 LS444123 60.0 43.0 15.6 49.0 20.2 7.1 13.2 SS 8 (8/7) 6 ACRBAE F 3260 LS444124 62.0 47.0 16.1 50.0 21.4 7.5 11.9 SS 8 8 6 ACRBAE F 3261 LS444125 62.0 47.5 18.4 53.0 22.3 8.7 12.2 1/SS 8 8 6/7 ACRBAE F 3262 LS444126 59.5 46.0 18.7 47.0 20.3 7.8 13.3 1/SS 8 8 7 ACRBAE F 3396 LS444127 62.0 47.0 14.3 50.0 21.1 8.6 11.9 1/SS 8 8 7 ACRBAE M 3397 LS444128 63.0 48.0 15.4 51.0 21.8 7.5 13.8 SS 8 (7) 8 7 ACRBAE M 3398 LS444129 63.0 50.0 16.0 52.0 22.6 10.2 13.2 SS 8 8 6/7 ACRBAE M 3399 LS444130 64.0 49.0 15.7 50.0 22.1 9.4 12.9 SS 8 (8/7) 6 ACRBAE F 3401 LS444131 63.0 48.0 15.6 52.0 21.8 8.7 13.1 SS 8 8 7 ACRBAE M 3403 LS444132 64.0 49.0 15.3 52.0 22.4 9.0 11.2 1 8 (7) 8 7 ACRSCI F 3400 LS444133 65.5 50.2 16.4 50.0 23.3 9.2 12.2 1 8 8 6/7 ACRSCI F 3402 LS444134 66.0 51.0 16.5 53.0 23.5 10.0 13.5 1/SS 8 8 6/7 ACRSCI M 3404 LS444135 66.0 52.0 17.1 54.0 22.9 10.5 12.7 SS 8 8 7 ACRSCI F 3405 LS444136 64.0 49.0 16.7 50.0 22.8 9.6 12.4 1 8 8 7/8 ACRSCI F 3406 LS444137 66.0 50.0 16.3 51.0 22.6 13.3 11.6 1 8 8 6/7 ACRSCI M 3755 LS444138 69.0 51.2 18.0 51.5 24.0 11.5 13.0 1 8 8 7

Vie Milieu, 2018, 68 (1) ACROCEPHALUS TAXONOMY 27

Table II. – Principal measurements (in mn) and wing formulae of Acrocephalus museum specimens belonging to the taxa considered in the text: A. baeticatus baeticatus (ACRBAEB), A. b. hallae (ACRBAEH), A. b. suhaelicus (ACRBAES), A. b. cinnamomaeus (ACR- BAEC), A. b. guiersi (ACRBAEG), A. scirpaceus (ACRSCI), A. agricola (ACRAGR), Blyth’s Reed Warbler A. dumetorum (ACRDUM), and A. palustris (ACRPAL). TRS: Tarsus length; E: emargination, W: wing point, 2: posi- tion of the tip of P2 (P9 descendent) in relation to the tips of the other primaries (sensu Svensson 1992). (Data from Kennerly & Pear- sons 2010). Species Wing Bill Tail TRS Notch length in mm E W 2 ACRBAEB 59.7 16.5 49.6 22.5 59.7 4 34 6/8 (56-63) (15.5-17.5) (44.0-53.0) (21.5-23.5) (56-63) SD = 1.6 N = 38 SD = 0.6 N = 30 SD = 2.3 N = 34 SD = 0.5 N = 22 SD = 1.6 N = 38 ACRBAEH 59.0 16.8 47.6 22.3 59.0 (57-63) (16.0-17.0) (45-53) (22.0-23.0) (57-63) SD = 2. N = 10 SD = 0.4 N = 6 SD = 2.5 N = 9 SD = 0.4 N = 6 SD = 2. N = 10 ACRBAES 59.1 17.5 48.9 21.8 59.1 (56-63) (17.0-18.5) (46-52) (21.0-23.0) (56-63) SD = 1.9 N = 15 SD = 0.5 N = 15 SD = 1.7 N = 15 SD = 0.8 N = 10 SD = 1.9 N = 15 ACRBAEC 54.4 15.8 44.5 21.2 54.4 4 35 7/9 (51-57) (15.0-18.0) (39-48) SD = 2.0 N = 29 (20.0-22.0) (51-57) SD = 1.4 N = 30 SD = 0.5 N = 27 SD = 0.7 N = 21 SD = 1.4 N = 30 ACRBAEG 58.0 16.0 47.2 21.4 58.0 4 34 6/7 (56-60) (15.5-16.5) (45-50) (21.0-22.0) (56-60) SD = 1.4 N = 5 SD = 0.5 N = 5 SD = 2.2 N = 3 SD = 0.6 N = 5 SD = 1.4 N = 5 ACRSCI 65.4 16.9 51.1 22.4 65.4 3 3 3/5 (63-69) (15.5-18.0) (48-55) (21.5-23.5) (63-69) SD = 1.7 N = 32 SD = 0.7 N = 24 SD = 1.8 N = 29 SD = 0.6 N = 31 SD = 1.7 N = 32 ACRAGR 57.7 14.8 52.5 21.7 57.7 5 34 6/8 (54.0-62.0) (13.0-16.0) (47.0-58.0) (20.0-23.0) (54.0-62.0) SD = 1.7 N = 76 SD = 0.6 N = 75 SD = 2.4 N = 73 SD = 0.7 N = 60 SD = 1.7 N = 76 ACRDUM 62.4 17.1 49.9 22.1 62.4 3-4 3 (4) 5/7 (59.0-65.0) (15.5-18.5) (46.0-54.0) (20.5-23.5) (59.0-65.0) SD = 1.5 N = 132 SD = 0.7 N = 123 SD = 1.9 N = 129 SD = 0.7 N = 56 SD = 1.5 N = 132 ACRPAL 68.4 15.8 51.3 22.4 68.4 3 3 3/5 (64.0-72.0) (14.5-17.0) (47.0-55.0) (21.0-23.5) (64.0-72.0) SD = 1.7 N = 43 SD = 0.6 N = 47 SD = 1.9 N = 43 SD = 0.7 N = 43 SD = 1.7 N = 43

In this study, involving Southern Burkina Faso reed bigger than the other subspecies and thus more similar to warbler populations, we followed the guidelines pro- A. scirpaceus. According to some authors (Fry et al. 2000, posed by Kennerly & Pearson (2010) who consider Kennerly & Pearson 2010), A. baeticatus can be reliably A. baeticatus a polytypic species with five subspecies: separated from A. scirpaceus based on the wing formula A. b. baeticatus in South, central and East South Africa; with emargination being the most important diagnostic A. b. cinnamomaeus in central, East and West Africa from character for the former species. S Zambia, Malawi, inland Mozambique, North to South Based on these assumptions, in this study we aimed Sudan, South Somalia and Ethiopia and West to Nigeria at confirming the occurrence of Acrocephalus baeticatus and South Niger; A. b. guiersi in Senegal and perhaps in in Burkina Faso using an integrated morphological and Mali (Niger Delta); A. b. hallae in West South Africa to molecular approach. Additionally, we used this case study Namibia, North-Western Botswana, South-Western Zam- to discuss the reliability of the wing formula in distin- bia and South Angola; and A. b. suahelicus in coastal guishing A. baeticatus from its conspecific A. scirpaceus areas of Tanzania, Mozambique and East South Africa when the two occur syntopically at the same wintering always associated with mangroves. Distinction between African site. these subspecies is provided mostly by geographical dis- tribution, color, and measurements. The African A. baeticatus resembles morphologically the MATERIAL AND METHODS European A. scirpaceus, which winters throughout most of the sub-Saharan Africa. However, they differ in size, wing The study has been conducted on sixteen Acrocephalus shape and coloration with A. baeticatus being smaller, with specimens (Table I) collected at Lemorodougou Lake (10°41’N; more rounded wing and different wing formula, and being 4°48’W) (Banfora, Cascade Region, Southern Burkina Faso, paler and greyer in Southern Africa (A. b. baeticatus), see Fig. 1) in the months of December, February and March brighter rusty in Eastern Africa (A. b. cinnamomaeus) and (Pavia et al. 2012). The lake was created as a water reservoir deeply rufescent in the South-East coast (A. b. suahelicus). for the sugar cane plantation by a small barrage in the Comoé The Western African subspecies A. b. guiersi is slightly River. The Lemorodougou Lake is completely bordered by thick

Vie Milieu, 2018, 68 (1) 28 M. PAVIA, A. GALIMBERTI, I. PELLEGRINO, F. SILVANO, D. ZUCCON, G. BOANO flooded reedmace Typha beds, of which the external parts are cut during the dry season to cultivate rice and millet. Specimens were preserved as study skins and tissues in the collections of the Museo Civico di Storia Naturale of Carmag- nola, Italy (MCCI) in the framework of an ongoing project for the study of bird systematics, phylogeography and bird parasites of Cascade Region (Giammarino et al. 2007, Pavia et al. 2012). For each bird standard measurements were taken (Svens- son 1992, Kennerly & Pearson 2010). In addition, the wing formula, the length and position of the notch of inner web the P9 were also measured (Table I). Notch length was measured to the nearest 0.5 mm from the point of inflection to the feather tip (Svensson 1992, Deutsche Ornithologen-Gesellschaft 2011, Malmhagen et al. 2013), whereas its position was evaluated on the closed wing following the indication of Malmhagen et al. (2013). Measurements and wing formula were used to achieve species identification (Fry et al. 2000, Kennerly & Pearson 2010). Specifically, these authors found that in all the investi- gated A. baeticatus, emargination was on the fourth outer pri- mary (P7, numbered descendantly), or rarely on the fifth one (P6, numbered descendantly), whereas in A. scirpaceus it was always on P8 (see Table II for further details). Moreover, all the recognized subspecies of A. baeticatus have a shorter second outer primary than A. scirpaceus, with tip at or below P5 (rarely Fig. 2. – Spread wing of African Reed Warbler Acrocephalus at P6 in A. scirpaceus). baeticatus (MCCI 3398) from Lemorodougou Lake (SW Burki- na Faso). The emargination on the outer web of P8 is clearly For each individual, a tissue sample was isolated from pecto- visible, while it is only hinted on P7 (see Table I). ral or leg muscle and preserved in ethanol 95° and species iden- tification was verified using a DNA barcoding COI (mtDNA)- based approach (Johnsen et al. 2010). The obtained nucleotide nominate subspecies as suggested by the morphological sequences (see Table I) were compared to the international analysis. The 10 shorter-winged specimens clustered in databases GenBank (https://www.ncbi.nlm.nih.gov/) and BOLD another clade that is the one of the African A. baeticatus. (http://www.boldsystems.org/) using the BLAST and IDS tools Morphological description: The sixteen Reed Warblers respectively. Specimens sex (Table I) was established by gonad- specimens from Lemorodougou Lake were very similar al inspection and rechecked with the primer pair 2550F/2718R in overall aspect and coloration, including that of the bare following the protocol of Fridolfsson & Ellegren (1999). parts. None of the was in active moult at the time of capture and the plumage showed similar degree of abra- sion in all specimens. Birds plumage was warm brown RESULTS above and buffy below with whitish throat and belly, nar- row buffy supercilium in front of the eye, bicoloured bill DNA barcoding identification: High quality DNA with flesh-yellowish mandible, and greenish grey legs. barcoding sequences longer than 650 bp were obtained Surprisingly, concerning wing formula, all but two of for each analysed sample. Six and two haplotypes were the sixteen Acrocephalus caught at Lemorodougou Lake found in A. baeticatus and A. scirpaceus COI sequences had only the P8 emarginated (Fig. 2). The other two indi- respectively, thus indicating a moderate genetic structure viduals, which were those with shorter wings, showed a that deserves further investigations. However, both Gen- hint of emargination on the P7 (Table I). Bank and BOLD confirmed that all samples collected Comparison of the measurements between the ten from the study area belonged to A. baeticatus and A. scir- Acrocephalus baeticatus (bae) and the six A. scirpa- paceus (see Table II) with p-distance values lower than ceus (sci) genotyped specimens (Table I), shows statis- 1 % (range 0-0.6 %) between sequences obtained in this tically significant differences (Student t-test for non study and reference barcode sequences stored in the inter- paired data) for the mean values of: wing minimum national databases. chord (bae = 59.9 mm, sci = 63.5 mm, df 14 t = 5.5114, The genotyping of the Burkina specimens supports p = 0.0001), wing maximum chord (bae = 62.2 mm, their separation in two groups, matching the differences sci = 66.1 mm, df 14 t = 4.7751, p = 0.0003), primary pro- observed in size, shape and color. The six longer-winged jection (bae = 14.6 mm, sci = 16.1 mm, df 14 t = 3.0450, individuals were confirmed as wintering individuals of p = 0.0087) body mass (bae = 8.4 g, sci = 10.7 g, the European A. scirpaceus, probably belonging to the df 14 t = 3.6318 p = 0.0027), tarsus (bae = 21.6 mm,

Vie Milieu, 2018, 68 (1) ACROCEPHALUS TAXONOMY 29

Fig. 3. – Sample sizes for the relationships between notch position (P8) and wing length (upper) and notch length (P8) and wing length (lower) in African Reed Warbler Acrocephalus baeticatus (in black) and European Reed Warbler A. scirpaceus (in red) from Lemoro- dougou Lake (SW Burkina Faso), plotted on the areas representing 95 % confidence ellipses for adults Paddyfield Warbler A. agricola (red), Blyth’s Reed Warbler A. dumetorum (blue), A. scirpaceus (yellow), and Marsh Warbler A. palustris (green); the areas in violet and light green represent overlaps between species. The original data of the present work have been plotted on a figure modified after Malmhagen et al. (2013) sci = 23.2 mm, df 14 t = 4.1214, p = 0.0036), P8 already identified on the basis of genetic analysis, mor- (bae = 47.5 mm, sci = 50.6 mm, df 14 t = 3.5805, phological and morphometrical characters on the 95 % p = 0.0030); while other measurements are not signifi- confidence region of the value obtained by Malmhagen cantly different. et al. (2013) (Fig. 3). Even if the values of the two spe- In addition to the standard biometries and the wing for- cies are, as expected, not so far from each other, the val- mula, different authors suggested alternative methods to ues of A. baeticatus are closer to those of A. dumetorum, separate the unstreaked European Acrocephalus warblers the Blyth’s Reed Warbler, while the values of A. scirpa- (Walinder et al. 1988, Wilson et al. 2001, Malmhagen et ceus from Lemorodougou Lake fall well within the lower al. 2013) mainly based on the combination of wing length range of European individuals (Svensson 1992). The and position and length of the notch on the P9. Malmha- similarity in wing shape supported the hypothesis of the gen et al. (2013) provided a review of other methods and synonymy of A. baeticatus with A. dumetorum (Fry et al. demonstrated that the values of notch length and position 1974). However, this character is homoplastic, as the dif- with respect to wing length are reliable and repeatable ferences in song characteristics, migration ecology (Dow- criteria to separate unstreaked Palaearctic Acrocepha- sett-Lemaire & Dowsett 1987), and the genetic data (Hel- lus warblers in the hand. We plotted the notch/wing and big & Seibold 1999, Arbabi et al. 2014, and present work) notch position/wing values taken from the individuals of support the recognition of A. baeticatus and A. dumeto- A. baeticatus and A. scirpaceus from Lemorodougou Lake rum as two distinct species (Kennerly & Pearson 2010).

Vie Milieu, 2018, 68 (1) 30 M. PAVIA, A. GALIMBERTI, I. PELLEGRINO, F. SILVANO, D. ZUCCON, G. BOANO

Fig. 4. – Distribution of African Reed Warbler Acrocephalus baeticatus with the putative bor- ders between the various subspecies considered in this paper. The red star represents the position of the study area (modified after Kennerly & Pearson 2010).

DISCUSSION tus. In addition, the analysis of the wing morphology on a wider series of specimens belonging to various subspecies Our integrated identification approach confirmed the of A. baeticatus of the whole Africa continent will allow presence of a new population of Acrocephalus baetica- to support the robustness of wing formula and primary tus in Southern Burkina Faso, as preliminary suggested emargination patterns (Kennerly & Pearson 2010). (Pavia et al. 2012). Considering the relatively recent ori- The morphological separation of Acrocephalus baeti- gin of Lemorodougou Lake, the surrounding reedmace catus from the European A. scirpaceus and A. palustris is was probably colonized by A. baeticatus dispersing from a crucial point in the study of African bird community, as some natural marshes along rivers, other irrigation ponds the latter are syntopic with A. baeticatus in most of their or rice fields and also constitute a wintering area for Euro- winter range. Concerning the specimens here analysed, pean populations of A. scirpaceus. the morphological features are not fully effective in iden- Our identification data clearly support the inclusion of tifying Acrocephalus species, in particular concerning the the reed warbler population from Burkina Faso among the primary emargination (cf Kennerly & Pearson 2010). We West African forms of Acrocephalus baeticatus, although followed the methodology proposed by Malmhagen et al. a deeper sampling is needed to shed light on taxonomy (2013) using the P9 notch/wing and P9 notch position/ and relationships within this polytypic group. Differences wing values and we found that the individuals of A. baet- in wing morphology between the Burkina Faso birds and icatus never fall within the pure range of A. scirpaceus all the other known African subspecies and in particular (Fig. 3), as also confirmed by DNA barcoding identifica- the shift of emargination from P7 (or P6) to P8 in the indi- tion approach. In addition, as the same values calculated viduals from Lemorodougou Lake, confirm the peculiar- for A. palustris are clearly different (Fig. 3), we suggest ity of this population within the West African forms. To that the same method can be applied in the overall distri- the best of our knowledge, this wing shape seems com- bution range of A. baeticatus. pletely different from those of conspecifics from Senegal Further specific researches in the water reservoirs of (A. b. guiersi) and Central Africa (A. b. cinnamomaeus) the Cascade Region and in other areas of the Burkina (Kennerly & Pearson 2010). Faso could better define the status and distribution of The distribution of A. baeticatus subspecies (Kennerly this newly discovered population in Southern Burkina & Pearson 2010) (Fig. 4) shows the presence of a popula- Faso and its eventual connection with the Malian one or tion of A. baeticatus in Mali that has not been taxonomi- with others of Central Africa. This will certainly help to cally described (Lamarche 1981). This population is the confirm the importance of these natural and seminatural geographically closest to that of Lemorodougou Lake and patches as they clearly act as an unexpected reservoir of its morphological and genetic analysis could help clarify- genetic and taxonomic diversity for reed warblers, also ing its similarities with it and its relationships within the including wintering populations from European coun- comprehensive Western African population of A. baetica- tries.

Vie Milieu, 2018, 68 (1) ACROCEPHALUS TAXONOMY 31

Acknowledgments . – We are grateful to K Mamadou, I Tou Fry CH, Williamson K, Ferguson-Lees IJ 1974. A new subspe- and A Belemsobgo and the other people of the AGEREF/CL for cies of Acrocephalus baeticatus from Lake Chad and a taxo- their hospitality and the help during the fieldworks. The field nomic reappraisal of Acrocephalus dumetorum. Ibis 116: 340-346. work was partially financed by the action “Alimentation,������������������ Eco- tourisme et Nature : microprojets écologiques dans la foret clas- Fry CH, Keith S, Urban MK 2000. The Birds of Africa, Vol VI: Picathartes to Oxpeckers. Academic Press, London, UK. sée de la Comoé-Léraba” within the cooperation project between Burkina Faso and the Provincia di Vercelli, Settore Risorse Giammarino M, Vaschetti G, Boano G 2007. Blood parasites in birds from Burkina Faso. Parassitologia 49: 55-57. Umane, Tutela Ambientale e Sanità. We thank the Minister of the Environment and Sustainable Development of Burkina Faso Helbig AJ, Seibold I. 1999. Molecular phylogeny of Palearctic- African Acrocephalus and Hippolais warblers (Aves: Sylvii- for the support of our research. In particular we thank the Direc- dae). Mol Phylogenet Evol 11: 246-260. tor of the Faunal Office, Urbain Belemsobgo, for his help with Johnsen A, Rindal E, Ericson P, Zuccon D, Kerr K, Stoeckle M, permits and for his enthusiasm for our work. The fieldworks Lifjeld J 2010. DNA barcoding of Scandinavian birds reveals have been conducted with the permission of the Ministère de divergent lineages in trans-Atlantic species. J Ornithol 151: l’Environnement et du Cadre de Vie of Burkina Faso, Permit 565-578. N° 2010-013/MECV/CAB. We also wish to thank the editor L Kennerley P, Pearson DJ 2010. Reed and Bush Warblers. Chris- Luiselli for inviting us to submit this contribution. This work topher Helm, London, UK. has been supported by Torino University Grant ex 60 % 2016 Lamarche B 1981. Liste commentée des Oiseaux du Mali. and 2017 to MP. Malimbus 3: 73-102. Leisler B, Heidrich P, Schulze-Hagen K, Wink M 1997. Taxono- my and phylogeny of reed warblers (genus Acrocephalus) REFERENCES based on mtDNA sequences and morphology. J Ornithol 138: 469-496. Alemayehu Y, Welegerima K, Meheretu Y 2017. Importance of Lungren C, Oueda GH, Walsh F, Belemsobgo U 2001. Burkina Lake Ashenge, a small Important Bird Area in Northern Ethi- Faso. In Fishpool LDC, Evans MI eds, Important Bird Areas opia, to Palaearctic and other migratory birds. Afric J Wildlife in Africa and Associated Islands: Priority Sites for Conserva- Res 47(1): 1-9. tion. Pisces Publications and BirdLife International (BirdLife Conservation Series No. 11), Newbury and Cambridge, UK. Amezian M, Cortes J, Thompson I, Bensusan K, Perez C, Louah A, Qninba A 2010. Complete moult of an undescribed resi- Malmhagen B, Karlsson MNB, Menzie S 2013. Using wing morphology to separate four species of Acrocephalus war- dent taxon of the Reed Warbler Acrocephalus scirpaceus / blers in Scandinavia. Ringing Migration 28: 63-68. baeticatus complex in the Smir marshes, Northern Morocco. Ardea 3(98): 225-234. Olsson U, Rguibi-Idrissi H, Copete JL, Arroyo Matos JL, Prov- ost P, Amezian M, Alström P, Jiguet F 2016. Mitochondrial Arbabi T, Gonzalez J, Wink M 2014. A Re-evaluation of phylo- phylogeny of the Eurasian/African reed warbler complex genetic relationships within Reed Warblers (Aves: Acro- (Acrocephalus, Aves). Disagreement between morphological cephalidae) based on eight molecular loci and ISSR profiles. and molecular evidence and cryptic divergence: A case for Mol Phylogenet Evol 78: 304-313. resurrecting Calamoherpe ambigua Brehm 1857. Mol Phylo- Borrow N, Demey R 2014. Birds of Western Africa. Second genet Evol 102: 30-44. edit. Christopher Helm, London, UK. Pavia M, Boano G, Silvano F, Karama M 2012. New bird del Hoyo J, Elliott A, Sargatal J 2006. Handbook of the birds of records from southwestern Burkina Faso. Malimbus 34: the world. Old World Flycatchers to Old World Warblers. 57-81 Lynx Edicions, Barcelona, Spain. Söderström B, Kiema S, Reid RS 2003. Intensified agricultural del Hoyo J, Collar NJ 2016. HBW and BirdLife International land-use and bird conservation in Burkina Faso. Agricult illustrated checklist of the Birds of the World. Volume 2: Pas- ecosyst environ 99 (1): 113-124. serines. Lynx Edicion, Barcelona, Spain. Svensson L. Identification Guide to European . Pri- Deutsche Ornithologen-Gesellschaft 2011. Measuring birds / vately published, Stockholm 1992. Vögel vermessen. Deutsche Ornithologen-Gesellschaft, Wil- Walinder G, Karlsson L, Persson K 1988. A new method for helmshaven, Germany. separating Marsh Warbler (Acrocephalus palustris) from Dickinson EC, Christidis L eds 2014. The Howard & Moore Reed Warbler (Acrocephalus scirpaceus). Ringing Migration complete Checklist of the Birds of the World. 4th Edit., Vol. 2. 9: 55-62. Aves Press, Eastbourne UK. Wilson JD, Akriotis T, Balmer DE, Kyrkos A 2001. Identifica- Dowsett-Lemaire F, Dowsett RJ 1987. European and African tion of Marsh Warblers Acrocephalus palustris and Reed reed warblers, Acrocephalus scirpaceus and A. baeticatus; Warblers A. scirpaceus on autumn migration through the vocal and other evidence for a single species. Bull Br Orni- eastern Mediterranean. Ringing Migration 20: 224-232. thol Club 107: 74-85. Wymenga E, Zwarts L 2010. Use of Rice Fields by birds in West Fridolfsson AK, Ellegren H 1999. A simple and universal meth- Africa. Waterbirds 33: 97-104. od for molecular sexing of non-ratite birds. J Avian Biol 30: Received on September 11, 2017 116-121. Accepted on November 20, 2017

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