CONSERVATION
IUCN Redlist category Data Deficient (IUCN 2020)
Rationale for redlist categorization Troides plato has been assessed as Data Deficient. This species was considered very rare by many authors in the 1970s and 1980s and there is a lack of current data exists on the population status of this species. Its extent of occurrence is estimated to be no more than 37,000 km?, but may be considerably less; there are no locality data available to properly estimate area of occupancy which is likely much smaller for this localised species, and based on estimated area of remaining forest is likely to be at most 3,000 km?. In the past, there was concern about the survival of this species given the high rates of deforestation on Timor; at present, much of the land cover on the island is dedicated to agriculture, with few forested areas remaining. This is likely to be a species under threat, but given the lack of information on habitat, ecology and most importantly recent population trends of this species, more research is needed to monitor populations of this species and elucidate habitat requirements to inform future reassessments of this species. (IUCN 2020)
Threat category Ecosystem conversion|Ecosystem degradation (IUCN 2020)
Cause of stress (IUCN 2020)
Described Threats The species is listed on CITES Appendix II together with the genera Ornithoptera and Trogonoptera , with the exception of O. alexandrae which is listed on Appendix I. Recently traded individuals appear to come mostly from captive or ranched populations (CITES 2015). Butterfly ranching is generally thought of as a sound, economically viable and sustainable rural industry (Wambi 1996, Hanscom 1993, Burrows 2003 in Small 2007). However, there are concerns that butterfly ranching may not be as sustainable in some countries as it is often perceived to be (e.g., Papua New Guinea; Small 2007). This is based on a lack of data and species monitoring to assess the status of butterfly populations, and for many species, such monitoring is fraught with difficulty due to inaccessibility of their habitat (Small 2007). New and Collins (1991) noted that trade is extremely difficult to monitor because transportation of unpinned specimens is easy, especially of comparatively low value species which may instead be traded at high volumes. It has been stated that overcollecting seldom becomes a threat to butterflies, due to the reproductive capacity of insects and the difficulty in capturing significant numbers of the population (Pyle and Hughes 1978, in Parsons 1992). However, where birdwing butterflies are highly specific to host plants and where density of these hosts plants limits population size, collection in conjunction with habitat loss could have significant impacts on the species or subpopulations.
In the 1970s, D'Abrera (1975) had raised concerns with regard to the rates of deforestation on Timor Island as this may adversely affect the species. In fact, at present there is very little forest cover left on the island, with much of it dedicated to agricultural land uses according to Global Forest Watch; between 2001 and 2016, East Timor alone lost 22.8 kha of tree cover (Hansen et al. 2013). In 2010, only around one third (5,610 km?) of the area of Timor-Leste (15,410 km?) retained forest cover of more than 30% canopy density in 2010 (Hansen et al. 2013). Data for the Indonesian part of Timor (with a similar land area overall) are more difficult to obtain, although inspection of maps suggests that a higher proportion of land area is void of similarly dense forest (Hansen et al. 2013). Assuming a quarter of tree cover remaining in Indonesian Timor and a third in Timor Leste, and assuming there is no relationship with altitude and forest loss, suggests that around 3,000 km? of forest with canopy density of 30% remain within the species range. Given that there is a lack of data on ecological requirements of this species, it is difficult to assess if the species can occur in more open landscapes such as those dominating Timor, but at present based on limited evidence we assume that this is a primarily forest species. If the species relies on denser forest, the remaining area available to it on Timor is likely to be less than 3,000 km?. (IUCN 2020)
Commercial use Butterflies are mostly traded dead for the curio market (Collins and Morris 1985, New and Collins 1991). Between 1998 to 2007, 306,000 butterflies were traded from Southeast Asia, with 13,000 of these being wild-caught (Nijman 2010). There is a distinct shift towards ranched and captive-bred individuals in trade from 2003 onwards; in 1985, it was reported that globally less than 10% of trade was in ranched individuals (Collins and Morris 1985). Altogether at least 34 different species were recorded in trade, most of which belonged to the birdwing butterflies ( Troides and Ornithoptera ; Nijman 2010). It should be noted that trade in butterflies may be underreported, because of difficulties monitoring. New and Collins (1991) noted that trade is extremely difficult to monitor because transportation of unpinned specimens is easy, especially of comparatively low value species which may instead be traded at high volumes.
Birdwings can fetch high prices on the market. For example, butterfly collectors have paid high prices for birdwing butterflies of this genus: a pair of Ornithoptera meridionalis was reported to have fetched USD 3,400 in Germany (Melisch and Schutz 2000). Reported prices for Troides are however much lower. For example, a more recent pricing was around $85 per pair of T. hypolitus , around $15 per individual of T. helena and between $43 and $85 per pair of T. haliphron (Putri 2016). This species is listed on Appendix II of CITES. Recent data from the CITES Trade database show, that since 2000 and 2015 around 3,500 individuals were exported from Indonesia, none of which are from wild populations (CITES 2015). The species has reportedly been successfully reared outside its distribution (Weissmann et al. 1995). (IUCN 2020)
Applied conservation actions This species was not considered to be threatened during a global status assessment of the world's swallowtails in 1985, although at the time very little data were available on the species' distribution and population and more monitoring was recommended as an urgent action (Collins and Morris 1985). In 1991, New and Collins suggested work to fully integrate swallowtails into national conservation planning in Indonesia (1991), primarily for those species which were identified as threatened at the time - however, any such work is likely to have benefited all birdwing species in the country. The species is also protected in Indonesia (Collins and Morris 1985, Peraturan Pemerintah Republik Indonesia 1999). The species may occur in a number of protected areas within its range, specifically in the eastern parts of the island (WDPA 2016), although data are lacking to verify this. Given the lack of information on habitat, ecology and most importantly recent population trends of this species, more research is needed to monitor populations of this species and elucidate habitat requirements. (IUCN 2020)
REFERENCES
- CITES. 2015. CITES Trade Data Base. Available at: http://trade.cites.org/.
- Collins, N.M. and Morris, M.G. 1985. Threatened Swallowtail Butterflies of the World. The IUCN Red Data Book. IUCN, Gland and Cambridge.
- Hanscom, T. 1993. Setting hearts aflutter: little butterflies take wing as big business. The Rotarian 163: 16-19.
- Hansen, M.C., Potapov, P.V., Moore, R., Hancher, M., Turubanova, S.A., Tyukavina, A., Thau, D., Stehman, S.V., Goetz, S.J., Loveland, T.R., Kommareddy, A,. Egorov, A., Chini, L., Justice, C.O. and Townshend, J.R.G. 2013. High-resolution global maps of 21st-century forest cover change. Science 342: 850-853.
- IUCN. 2020. The IUCN Red List of Threatened Species. Version 2020-3. Available at: www.iucnredlist.org. (Accessed: 10 December 2020).
- Melisch, R. and Schutz, P. 2000. Butterflies and beetles in Germany. Traffic Bulletin 18: 91-93.
- New, T.R. and Collins, N.M. 1991. Swallowtail butterflies: an action plan for their conservation. International Union for Conservation of Nature and Natural Resources/Species Survival Commission Lepidoptera Specialist Group, Gland, Switzerland.
- Nijman, V. 2010. An overview of international wildlife trade from Southeast Asia. Biodiversity and Conservation 19(1101-1114).
- Parsons, M.J. 1992. The butterfly farming and trading industry in the Indo-Australian region and its role in tropical forest conservation. Tropical Lepidoptera 3(Suppl. 1): 1-31.
- Peraturan Pemerintah Republik Indonesia. 1999. Nomor 7 Tahun 1999 tentang Pengawetan Jenis Tumbuhan Dan Satwa.
- Putri, I.A.S.L.P. 2016. Handicraft of butterflies and moths (Insecta: Lepidoptera) in Bantimurung Nature Recreation Park and its implications on conservation. Biodiversitas 17(2): 823-831.
- Pyle, R.M. and Hughes, S.A. 1978. Conservation and Utilization of the Insect Resources of Papua New Guinea. Wildlife Branch, Department of Natural Resources, Port Moresby.
- Small, R.D.S. 2007. Becoming unsustainable? Recent trends in the formal sector of insect trading in Papua New Guinea. Oryx 41(3): 386-389.
- Wambi, D. 1996. Birds, bugs and butterflies. New Guinea Insight 6: 5-9.
- WDPA. 2016. Database on Protected Areas. A database online managed by UNEP-WCMC/IUCN World Commission on Protected Areas (WCPA). Available at: http://www.unep-wcmc.org/wdpa/index.htm.
- Weissmann, M.J., Lederhouse, R.C., and Elia, F.C. 1995. Butterfly gardening and butterfly houses and their influence on conservation in North America. In: Scriber, J.M., Tsubaki, Y. and Lederhouse, R.C. (eds), Swallowtail butterflies: Their ecology and evolutionary biology, pp. 393-400. Scientific Publishers, Gainesville.