Geographical partitioning of microsatellite variation in the sarus crane

Abstract

The sarus crane (Grus antigone) ranges across two continents and is the only species of crane (Gruidae) that breeds in India and Southeast Asia. Four subspecies, the Indian sarus (G. a. antigone), the eastern sarus (G. a. sharpii), the Australian sarus (G. a. gillae) and the extinct Philippine sarus (G. a. luzonica) were originally described through morphological, plumage, and/or geographical differences. The ranges of the Indian and eastern sarus converge in eastern India and Myanmar, but the Australian sarus has a disjunct Australian distribution. This study assesses population genetic structure of the current sarus populations utilising 13 DNA microsatellite loci. Population structure within this species was investigated utilising traditional F ST and Bayesian clustering methods. While significant divergence was observed among populations when individuals were assigned to geographical populations, analyses based solely on individual genotypes demonstrated a clinal nature to the variation. The results of this study suggest that the Indian and eastern sarus cranes represent two major breeding groups within Asia and that the birds from Myanmar probably reside in an introgression zone between them. Lastly, because of genetic similarities shown to the eastern sarus, the results support recent theories contending that the Australian sarus was derived from mainland Asian birds.

Screening and application of microsatellite markers for genetic diversity analysis of captive eastern sarus crane Grus antigone sharpii Blanford, 1895 in Thailand

“…These results suggest that the two populations of cranes from two breeding facilities might have originated from the same founder population in Cambodia. Previous microsatellite study by Jones et al () have shown that the estimated overall F ST value in the whole sarus crane range is 0.21, which is considerably high among populations. This value is higher than ours (0.023), which seems to support our assumption on sarus cranes common origin from Cambodian locality.…”

“…A monitoring program for such reintroduction is essential for the future preservation of this magnificent and majestic bird. Additionally, primers used in our work to assess genetic diversity and population structure of Thai sarus crane should be applicable to future conservation study of G. a. sharpii population throughout Southeast Asia, in particular the Burmese population, which exhibits distinct genetic structure from the Indochinese G. a. sharpii (Jones et al, ). Moreover, it would be great to apply these suitable primers on wild Cambodian cranes to compare directly on Thai captive populations to their wild ancestors.…”

“…This large non‐migratory crane is highly threatened in many countries in the Indian subcontinent and Southeast Asia (BirdLife International, ). Three extant G. antigone subspecies are recognized, the Indian sarus ( G. a. antigone ), the Australian sarus ( G. a. gillae ), and the eastern sarus ( G. a. sharpii ) (Archibald, Gopi Sundar, & Barzen, ; Meine & Archibald, ), which differ morphologically and geographically though genetically closely related (Das, ; Jones, Barzen, & Ashley, ; Wood & Krajewski, ). Grus a. antigone can be found in India, Nepal, Pakistan, and Bangladesh whereas G. a. gillae is restricted to north‐east Australia.…”

“…Map depicting (1) three G. a. sharpii captive breeding facilities in Thailand: BB (Bangpra Water Bird Breeding Station), KKOZ (Khao Kheow Open Zoo), and NZ (Nakhon Ratchasima Zoo); (2) two wetland areas for reintroduction: HCM (Huai Chorakhe Mak Non‐Hunting Area) and SNB (Sanambin Reservoir Non‐Hunting Area); (3) six areas of G. a. sharpii in northern Cambodia: ATT (Ang Trapeang Thmor), KPWS (Kulen Promtep Wildlife Sanctuary), PNP (Preah Net Preah), PVPF (Preah Vihear Protected Forest), TLS (Tonle Sap Grasslands), WSP (Western Siem Pang). Shade areas indicate known distribution of G. a. sharpii in Cambodia, Laos, and Vietnam (modified from Jones et al, ; van Zalinge et al, )…”

Subspecies in the Sarus Crane Antigone antigone revisited; with particular reference to the Australian population

“…These subspecific arrangements, largely indicated by morphology (Fig 2), have not hitherto been strongly supported by genetic analyses. Application of molecular techniques to understand the subspecific arrangements of Sarus Cranes [30,31,32] suggested that colonisation of Australia by Sarus Cranes was relatively recent and there had been little differentiation of populations across their range [32].…”