CONSERVATION
IUCN Redlist category Least Concern (IUCN 2020)
Rationale for redlist categorization Pachliopta schadenbergi has been assessed as Least Concern. This species has an extent of occurrence of over 200,000 km2. Although this is likely an overestimation as it assumes the species occurs across Luzon, there is not sufficient data to provide an alternative area. There is concern that this species is severely affected by habitat loss that is occurring across Luzon, however there is not enough evidence to confirm that this is threatening the species enough to warrant a category other than Least Concern. Further, contemporary research into this species, most importantly into its distribution and habitat, would be very beneficial and may then result in a change of category. (IUCN 2020)
Threat category Species mortality,Ecosystem conversion (IUCN 2020)
Cause of stress Intentional use (species is the target),Shifting agriculture (IUCN 2020)
Described Threats The persistent degeneration and conversion of habitat for agricultural purposes is the major threat to this species (Tsukada and Nishiyama 1982). As its range is limited to very specific localities, its risk of extinction is heightened (Collins and Morris 1985). In Sierra Madre, although the land is protected in a National Park, this does not prevent illegal logging, and in fact when Greenpeace (2006) investigated illegal logging in nine different sites across this area they found that it was occurring in five of them. In northern Luzon, around 130,000 ha of forest (with canopy density >30%) has disappeared between 2001-2017 (Hansen et al. 2013). This species may also be threatened by trade as specimens are for sale, however it is unknown if and how much of an impact this has on this species. (IUCN 2020)
Commercial use A specimen of this species can be found for sale on eBay for around £27 (October 2018). However, further trade information is not available. (IUCN 2020)
Kind of conservation needed Site/area protection (IUCN 2020)
Applied conservation actions In a previous status assessment of the world's swallowtails, this species was considered to be Vulnerable (Collins and Morris 1985), an assessment which was reconfirmed in 1996 (Gimenez Dixon 1996), as well as by Danielsen and Treadaway in 2004. Following the status assessment in 1985, this and other Philippine species were considered a conservation priority in the subsequent swallowtail action plan (New and Collins 1991). Specifically, the authors called for provision of protected habitat for this and other important endemics (New and Collins 1991).
Northern Sierra Madre is reported to be the widest remaining tropical rainforest on the island of Luzon, and through the enactment of Republic Act 9125, 2001, the Sierra Madre was declared a National Park with a buffer zone of 1 km around the outside where land was also protected (Greenpeace 2006). Indeed, it is thought that the subspecies A. s. micholitzi occurs in the North Sierra Madre National Park, and that the subspecies A. s. schadenbergi probably occurs in Bataan National Park (Danielsen and Treadaway 2004). It is therefore very important that the land in these National Parks continues to be protected. Further research into whether trade is a threat to this species would be beneficial, and population monitoring is recommended to assess the impact of threats and effectiveness of conservation measures. (IUCN 2020)
REFERENCES
- Collins, N.M. and Morris, M.G. 1985. Threatened Swallowtail Butterflies of the World. The IUCN Red Data Book. IUCN, Gland and Cambridge.
- Danielsen, F. and Treadaway, C.G. 2004. Priority conservation areas for butterflies (Lepidoptera: Rhopalocera) in the Philippine islands. Animal Conservation 7: 79-92.
- Gimenez Dixon, M. 1996. The IUCN Red List of Threatened Species 1996: e.T2377A9435834.
- Greenpeace. 2006. Sierra Madre: Under Threat. Available at: https://www.greenpeace.org/seasia/ph/Global/seasia/report/2006/5/sierra-madre-under-threat.pdf. (Accessed: 10th October 2018).
- 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).
- 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.
- Tsukada, E. and Nishiyama, Y. 1982. Butterflies of the South East Asian islands. Plapac Co. Ltd., Tokyo.