The bats (Mammalia : Chiroptera) of the lower Waria Valley, Morobe Province, Papua New Guinea: a survey and comparison across habitat types using mist nets Jeff Dawson A,F , Craig Turner B,C , Oscar Pileng A,D , Andrew Farmer A , Cara McGary A , Chris Walsh A , Alexia Tamblyn B and Cossey Yosi E A Coral Cay Conservation, 1st Floor Block, 1 Elizabeth House, 39 York Road, London SW1 7NQ, UK. B Jaquelin Fisher Associates, 4 Yukon Road, London SW12 9PU, UK. C Current address: Zoological Society of London, Regents Park, London NW1 4RY, UK. D FORCERT, Walindi Nature Centre, Talasea Highway, West New Britain Province, Papua New Guinea. E Papua New Guinea Forest Research Institute, PO Box 314, Lae, Morobe Province, Papua New Guinea. F Corresponding author. Email: jeffdawson78@gmail.com Abstract. From June 2007 to February 2009 the Waria Valley Community Conservation and Sustainable Livelihoods Project completed a mist net survey of bats in the lower Waria Valley, Morobe Province, Papua New Guinea. The Waria Valley is located on the north coast of the Morobe Province ~190 km south-east of Lae, and still has large tracts of intact lowland hill and plain rainforest. Four broad habitats (agricultural, secondary forest edge, primary forest edge and primary forest) were surveyed using mist nets. A total of 596 individuals representing 11 species were caught, measured and identified over 8824 net-m h –1 across 99 nights. Within the limitations of this method, primary forest edge sites in general showed the highest degree of species richness and diversity and along with secondary forest edge sites were more even in species composition. Primary forest and agricultural sites were each dominated by a single species, Syconycteris australis and Macroglossus minimus respectively. Most captures were megachiropterans and microchiropterans were underrepresented, presumably in part because of the survey method employed. Received 5 August 2011, accepted 10 February 2012, published online 8 June 2012 Introduction The tropical rainforests of New Guinea (including the sovereign state of Papua New Guinea and West Papua Province of Indonesia) are among the last remaining wilderness areas on the planet; they cover almost 70% of the island (Mittermeier et al. 1998) and are the third largest tropical rainforest in the world after the Amazon and Congo forests (Brooks et al. 2006). They are rich in biodiversity, with Papua New Guinea itself containing over 5% of the total estimated world’s biodiversity (AusAID 2010) and New Guinea’s lowland tropical forests and subtropical moist forests ranked amongst the top 10 most ecologically diverse regions in the world (Brooks et al. 2006). The Order Chiroptera, the bats, is one of the most speciose mammalian groups found in forest habitats around the world and Papua New Guinea is no exception. Of the estimated 242 mammal species found within its borders, at least 91 are bats, although this is likely to be an underestimate due to the taxonomic uncertainty surrounding them and the relative paucity of fieldwork carried out. The bats of Papua New Guinea represent six of the 18 living families (as listed by the IUCN 2011) and almost 9% of the living bat species worldwide (Bonaccorso 1998). This compares favourably to other tropical islands such as Borneo with 92 species (Payne et al. 1985) and Madagascar with 39 species (IUCN 2011). Unsurprisingly given its location, Papua New Guinea shares many bat species with the neighbouring countries of Indonesia, Australia and the Solomon Islands. Despite these shared similarities nearly 28% of species are endemic to either Papua New Guinea or the island of New Guinea itself (Bonaccorso 1998). The Megachiroptera (Old World fruit bats) are represented by 34 species and the remaining 57 are Microchiroptera (Bonaccorso 1998). This is a high proportion of megachiropteran bats, representing about one-fifth of the world’s fruit bat species. Within New Guinea, bats have been recorded up to an altitude of 3200 m although the greatest diversity is to be found in lowland habitats below 500 m (Bonaccorso 1998). Globally, forest habitats have been identified as being particularly important for bats and a priority for conservation efforts (Mickleburgh et al. 1992). Papua New Guinea has a relatively small human population and, because of its relatively low density (~15 people km –2 ), still has most of its natural habitat intact, with 71% of the country’s total land area covered by forest Journal compilation Ó Australian Mammal Society 2012 www.publish.csiro.au/journals/am CSIRO PUBLISHING Australian Mammalogy http://dx.doi.org/10.1071/AM11030