Australian Field Ornithology 2019, 36, 168–172 http://dx.doi.org/10.20938/afo36168172 Notes on the distribution and plumage variation of Varied and Mangrove Honeyeaters Leo Joseph1*, Jeffrey L. Peters2, Ian J. Mason1 and Alex Drew1 1Australian National Wildlife Collection, National Research Collections Australia, CSIRO, G.P.O. Box 1700, Canberra ACT 2601, Australia 2Department of Biological Sciences, Wright State University, Dayton OH 45435, Ohio, United States of America *Corresponding author. Email: [email protected] Abstract. Considered conspecific in some recent literature, the Varied Gavicalis versicolor and Mangrove Honeyeaters G. fasciogularis have long been thought to intergrade in and around the city of Townsville, Queensland. Here we update knowledge concerning the distribution of these two species and their variation in plumage colour and pattern in the Townsville region. A lack of records between Lucinda and Townsville seems to reflect a real gap. Further work is required to clarify whether elsewhere Varied Honeyeaters may occasionally exclude Mangrove Honeyeaters in a given locality. If so, this may explain the seemingly inconsistent reports of one or the other at particular localities. Mangrove Honeyeaters immediately south of Townsville may be slightly yellower ventrally than populations further south. However, we argue that this is consistent with our genetic findings reported elsewhere and is not, we conclude, indicative of an undescribed subspecies. Introduction and ecology, he suggested that they are conspecific but advised further sampling between Cardwell in the north (where to that time only pure Varied Honeyeaters had Varied Gavicalis versicolor and Mangrove Honeyeaters been collected) and Townsville (from where he described G. fasciogularis replace each other latitudinally on intermediates). Noting that populations at Townsville and Australia’s eastern seaboard roughly north (Varied) and Ayr are intermediate in coloration but closest to Mangrove south (Mangrove) of the city of Townsville, Queensland Honeyeater, he reasoned that the zone of intergradation (Ford 1978; Schodde & Mason 1999). The Varied must be centred somewhere north of Townsville and south Honeyeater ranges in eastern Queensland from Cape York of Cardwell. Finally, Ford (1978, p. 73) noted a corollary that Peninsula and Torres Strait south to approximately Lucinda intergradation must be “fairly steep” because the distance and Townsville (Figure 1). It also occurs in New Guinea. between Cardwell and Townsville is only ~150 km. The Mangrove Honeyeater currently is understood to range from just south of Townsville southwards to Brisbane and Wolstenholme (1925) noted observations of what also northern New South Wales (see Schodde & Mason appeared to be either Varied Honeyeaters or birds more 1999; Higgins et al. 2001). A narrow hybrid zone is reputedly resembling Varied than Mangrove Honeyeaters at North centred on Townsville in north-eastern Queensland (Ford Keppel Island off Rockhampton ~600 km south-east 1978; Schodde & Mason 1999; Figure 1). Genomic study of Townsville. We shall return to this and other reports of the interactions between the two species in this zone of Varied Honeyeaters from south of Townsville in the of putative hybridisation is the focus of a separate paper Discussion. (Joseph et al. 2019). Schodde & Mason (1999, p. 237) argued that a slightly Ingram (1908) reported that Mangrove Honeyeaters from larger series of specimens than had been available to Inkerman (~100 km south of Townsville) have a paler ventral Ford (1978) affirmed that evidence for what they termed surface relative to populations further south. Later, Ford “character flow” (presumably meaning gene flow) is patchy (1978) examined five specimens that had been recently and localised. They retained the Varied and Mangrove collected between Townsville and ~100 km further north at Honeyeaters as separate species. They also noted the Ingham and other comparative material (unspecified) from patchy occurrence of these species between Halifax Bay the American Museum of Natural History, New York. Most of in the south and Townsville in the north. Molecular studies the latter was important comparative material of Mangrove (Nyari & Joseph 2011; Joseph et al. 2014; Marki et al. and Varied Honeyeaters from beyond the Townsville 2017) have since shown that these two species are not region of interest here. Ford (1978) argued that specimens each other’s closest relatives; contrary to expectations from Cleveland Bay, immediately south of Townsville, and based simply on their putative hybridisation, the Mangrove Inkerman, further south, were phenotypically intermediate Honeyeater and Singing Honeyeater G. virescens, which between Varied and Mangrove Honeyeaters, particularly is widespread in inland Australia, are each other’s closest on the ventral surface. He included a photograph of one relatives, and the Varied Honeyeater is the closest relative of those specimens aligned with specimens more typical to that pair of species. of Varied and Mangrove Honeyeaters. Ford’s (1978) The purpose of this note is to complement a separate conclusions were cautiously worded. For example, genomic study of contact between the two species (Joseph he noted that Varied and Mangrove Honeyeaters are et al. 2019). We briefly update knowledge on distribution connected by a population of intermediate coloration in and geographical variation in plumage colour and the region where it has been considered that they come patterning in these birds. Our scope for the latter focused in contact. When coupled with similarities in vocalisations on Mangrove Honeyeaters as a result of our genomic Varied and Mangrove Honeyeaters: Distribution and plumage variation 169 Figure 1. Left: Map showing approximate locations (orange-filled circles) and corresponding GPS coordinates (WGS-84) of locations of unsuccessful searches for Mangrove and Varied Honeyeaters by AD and IJM in May 2015 between Lucinda and Townsville (black squares). Right: Two specimens from the Australian National Wildlife Collection (ANWC) collected in May 2015 from the northern and southern side of Townsville, respectively, a Varied Honeyeater ANWC B57007 (left) and a Mangrove Honeyeater ANWC B57006 (right) separated by a straight-line distance of <5 km. findings. We hope that the study reported here will guide Plumage any further quantitative study of plumage variation in this species. We qualitatively assessed plumage colour and patterning through admittedly preliminary examination of all specimens held in the Australian National Wildlife Collection (ANWC). Methods We assessed variation in colour particularly on the underparts where we focused on colour and pattern of the throat, chest and belly. Distribution In May 2015, AD and IJM searched 18 localities Results specifically for Varied and Mangrove Honeyeaters north and south of Townsville, from Lucinda (Taylors Beach and Toomulla Road south of Lucinda) to just south of Distribution Townsville (Figure 1). Recordings of vocalisations (Varied Online resources indicate records of Mangrove or Varied or Mangrove Honeyeater, depending on whether north or Honeyeaters from several localities in and around Lucinda south of Townsville, respectively) were played to attract at the north of the zone of interest. Apart from the many birds. Responses, when they occurred, were almost records in Lucinda itself, almost all such records were from always immediate. In the absence of a response, the historical literature and of imprecise and indeterminate observers departed from the locality within 5 minutes. locality (e.g. “Queensland”). One, a specimen record We also examined literature sources (Ford 1978; Ford from Ingham (Queen Victoria Museum and Art Gallery, et al. 1981; Storr 1984; Wieneke 2000; Nielsen 2015) and Launceston, Tasmania, 2006:2:15550), is a single- online resources (Atlas of Living Australia https://www. egg clutch, collected from a nest in a drooping branch ala.org.au/ and eBird https://ebird.org/home; accessed ~1 m above the water level on 20 September 1961 by 12 July 2019) for distributional records. Between 1978 and H. Gatebridge (D. Maynard pers. comm.). Nielsen (2015, 1999, Mangrove and Varied Honeyeaters were considered p. 339) referred to a “large population” of Mangrove conspecific so observers before the 2000s tended not to Honeyeaters about Lucinda, which is based on sightings differentiate between the two, simply recording them as by John Young between c. 1979 and 1996 (L. Nielsen pers. Varied Honeyeaters. This means that caution is warranted comm. 4 April 2018). Conversely, Nielsen (2015, p. 339) in interpreting literature records. also noted the Ross River further south in Townsville as 170 Australian Field Ornithology L. Joseph et al. Figure 2. Representative series of Mangrove Honeyeaters from Townsville, Queensland (left) to northern New South Wales (right). All are held in the ANWC. From left to right, with abbreviated localities and the B prefix of the registration numbers omitted for brevity: 57006 (Townsville), 29009-29017-29010 (1 km S of Ross River mouth), 56984-31208-28779-28780 (25–30 km SE of Ayr), 31192-28774-31191-31193 (40 km SE of Ayr), 57004-57005 (5 km SE of Bowen), 39469 (SE of Proserpine), 39473-39470 (Cape Conway Peninsula), 31130-28770-31129-28769 (N of Mackay), 39253 (Tweed Heads), and 39339 (N of Bundaberg). the “dividing line” between the two species (D. James in were 4.6 km apart in a straight line and separated essentially Nielsen 2015).