|Scientific Name:||Ornithoptera alexandrae (Rothschild, 1907)|
Aetheoptera alexandrae Rothschild 1907
Troides alexandrae Rothschild, 1907
|Taxonomic Source(s):||Haeuser, C. L., Holstein, J. and Steiner, A. 2012. The Global Butterfly Information System. Last updated 05.02.2014. Available at: http://www.globis.insects-online.de. (Accessed: 15 March 2016).|
|Taxonomic Notes:||Note, for the birdwing butterflies, genera Ornithoptera, Trogonoptera and Troides, specific and subspecific status follows D'Abrera. Subsequent revisions have been referenced but only totally new taxa have been added. Subspecies are listed where possible as they may occasionally be listed as full species.|
|Red List Category & Criteria:||Endangered B2ab(iii) ver 3.1|
|Reviewer(s):||Gerlach, J. & Mumford, N.|
Ornithoptera alexandrae has been assessed as Endangered under criterion B2ab(iii). The species is very rare and has a very restricted extent of occurrence of 8,710 km², suggesting a Vulnerable category, while its area of occupancy of 128 to 140 km², places it within the Endangered category. The species is easily over-represented in population counts of adults. In addition, it is confined to a maximum of five locations and is affected by the conversion of habitat to agriculture, with habitat conversion leading to a decline in available food plant vines. While placed on CITES Appendix I, with international trade prohibited, this species is highly prized. Better monitoring for this species is recommended to keep track of population trajectories.
|Previously published Red List assessments:|
|Range Description:||This species is endemic to the island of New Guinea, where all occurrence records are currently known from southeastern Papua New Guinea (D'Abrera 1971, Straatman 1971, Collins and Morris 1985, Parsons 1999, Matsuka 2001, Schaeffler 2001), north of the Owen Stanley range (Haugum and Low 1979). Some of the older records, including the type specimen (a small atypical female), may be dubious, as the species has not been seen outside the Popondetta Plains region (Collins and Morris 1985), apart from a nearby separate, higher altitude population (Collins and Morris 1985). Specifically, this means that the species is known from the Popondetta Plains and Afore area (Collins and Morris 1985, Parsons 1999, Murata 2008), and has been mainly observed in low-lying regions (of less than 200 m Asl; Matsuka 2001), although it has been recorded in a population not far from the larger lowland populations and at altitudes of up to 900 m (Straatman 1971, Parsons 1980b, Collins and Morris 1985), and more usually up to 800 m (Parsons 1999). A record of the species at 1,200 m is likely erroneous, and an altitudinal range of 0-850 m is now assumed to be the case for this species, given its occurrence in the Afore area and the surrounding Managalese Plateau (Parsons 1999, Matsuka 2001). It has also been suggested that the species may be retreating from higher altitudes, thus leaving it with its current restricted range (Haugum and Low 1979). The estimated extent of occurrence of this species is around 8,710 km², though this includes uncertain records. Focusing on certain records only, the estimated extent of occurrence is much lower, at 2,800 km². The species is found in a maximum of five locations, based on four confirmed subpopulations (Parsons 1999, Mercer 1999), with a potential fifth listed in some publications (e.g., Matsuka 2001), all of which are affected by forest loss. An approximation of its area of occupancy is under 140 km².|
Native:Papua New Guinea
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This species is likely to occur in four subpopulations in eastern Papua New Guinea: Cape Ward Hunt, Popondetta, Sibium Mountains and Upper Musa Valley (Parsons 1999, Mercer 1999). Some publications appear to give a fifth subpopulation, though this requires confirmation (e.g. Matsuka 2001). In the past, there have been conflicting statements on the occurrence of this species: for example, D'Abrera (1971) consider the species to be rare, while Haugum and Low (1979) considered it to be locally not rare in and around Popondetta. More recently, given the species' restricted range where it has so far only ever been recorded in fourteen 10 km grid squares in the east of Papua New Guinea, it is considered to be genuinely rare and extremely local in occurrence (Parsons 1999). However, where it occurs in close association with its larval food plants, it may be locally occasional to common (equivalent of around 2-10 individuals spotted over a 10-day period; Parsons 1999). Specifically, in the area between Kapurakambo and Sanananda, Parsons (1991) observed the species in good numbers (11 individuals of which four were adults and seven were larvae). Thomas (1992) recorded the species from a new grid square and in good numbers on the Managalase Plateau, at Ondoro Village, having observed adult females 16 times and adult males 14 times. Several surveys have been carried out for the species throughout the years, namely by Straatman in 1967, 1968 and 1970 (Straatman 1970, in Parsons 1999) and Parsons in 1980 and 1981 and 1991 (Parsons 1999) and leading to the recommendation of a species action plan being submitted to the World Bank (Parsons 1992). Specifically, a 10-day Managalese survey employing 28 surveyors recorded only seven larvae and one pupa (Mercer 1992, in Parsons 1999), although large numbers of adults were deemed to have been observed (82 adult males and 85 adult females) - however, these numbers should be taken with caution and are likely over-representations, given the ease at which adults of this large and strong, wide-ranging flyer may be re-recorded by multiple observers. A 50-day survey by Parsons (1991) with an average of 5 observers recorded only 23 larvae over the area of the Popondetta Plain and Afore area.|
|Current Population Trend:||Unknown|
|Habitat and Ecology:||This species is the largest butterfly in the world, with a wingspan of up to 250 mm (Collins and Morris 1985). It is restricted to primary and advanced secondary lowland rain forest and the lower montane secondary rainforest of the Afore area (Haugum and Low 1979, Collins and Morris 1985, Parsons 1999). It was previously thought to be a monophagous species, with Aristolochia dielsiana (formerly A. schlechteri) as its host plant (Straatman and Inoue 1984), although under experimental conditions, the closely related A. tagala was readily accepted by larvae (Straatman 1971). Since then other host plants have been determined, namely Pararistolochia alexandriana and P. meridionaliana (Parsons 1999, Matsuka 2001). Both these food plants occur in the area between Kapurakambo and Sanananda, which contained both an abundance of P. meridionaliana vines and good numbers (11 individuals of which four were adults and seven were larvae) of O. alexandrae (Parsons 1991).|
The species is far more restricted than the distribution of its food plants and does not occur in some areas where food plants are abundant (Straatman 1970, Parsons 1999). This may be because the species is generally found in areas where the forest is light and appears to avoid areas of thorny plants, probably due to their wing size (Straatman 1970). It has also been suggested that there may be some other barriers (e.g. microclimate) preventing species occurrence (Haugum and Low 1979). Adults generally fly high above the upper forest canopy where they presumably search for flowers of rain forest trees (Haugum and Low 1979, Parsons 1999). Oviposition may take place high in the top of tall trees if the food plants vine occur this high up in primary forests (Straatman 1971); in secondary forest, where trees and vines are less tall, oviposition takes place closer to the ground (Straatman 1971, Haugum and Low 1979). Eggs are laid singly on the underside of leaves of the food plant (Straatman 1971, Haugum and Low 1979). Eggs hatch after an average of 12 days; total larval duration from egg to pupa is 107 to 131 days (Straatman 1971), though this may reach up to 180 days in higher altitudes.
Adult females are most frequently observed at flowers of species such as introduced ornamentals Spathodea campanulata, Hibiscus rosa, Euphorbia pulcherrina, Ixora chinensis and Poinciana spp. and the crop tree Caffea arabica (Parsons 1999). Male adult have been reported to feed on Deplanchaea spp and kwila trees Intsia bijuga (Parsons 1999).
Predation pressure is low in adults, although there have been reports of mortality from birds such as kingfishers and orb web spiders Nephila maculata (Parsons 1999). Eggs have been reportedly attacked by ants and Heteroptera bugs, and larvae are preyed upon by wasps (Vespa spp.), ants, tree rats, small marsupials, toads, lizards and birds such as cuckoos, drongos and crow pheasants (Straatman 1971, Haugum and Low 1979, Collins and Morris 1985, Parsons 1999). There is uncertainty over the role of parasitism on this species, but unidentified tachinid flies were reported to parasitise on larvae and parasitic wasps on pupae (Straatman 1971, Haugum and Low 1978-79, Collins and Morris 1985).
Development to adulthood has been reported as 131 days (undergoing six instars), with development taking longer at higher altitudes (Straatman 1971). Marking of adult males suggest an adult lifespan of around 11-12 weeks (Straatman 1971). Females have been estimated to produce no more than 240 eggs during their lifetime (Parsons 1999).
|Use and Trade:||
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). Collectors in the past paid as much as $2,850 for an imperfect male specimen of O. alexandrae (Collins and Morris 1985), however, this species has been listed on Appendix I of CITES since 1987, which prohibits international trade in specimens of this species except when the purpose of the import is not commercial (New and Collins 1991). Hence, only few import and export records of specimens for scientific study have been reported (CITES 2015).
The main threat to the species is habitat destruction, which has been noted as early as 1971 by D'Abrera who suggested that the species is becoming increasingly rare due to collecting and cutting down of forest which destroys growth of larval food plant. Specifically, the species is threatened by habitat destruction for plantation of income-generating crops such as oil palm (Allan 1985, Collins and Morris 1985, Parsons 1992, New 2007). Cocoa and rubber plantations have also been a problem in the past; in fact as early as 1983, the species was suggested to be endangered because of its limited range and the threats to its forest habitat in the Popondetta Plain from oil palm and timber industries (Parsons 1983, Allan 1985). Overall, it has been suggested that illegal collecting is not comparable with loss of habitat as a threat (Collins and Morris 1985). There has been some forest cover loss specifically within the Popondetta region between 2001 and 2014 (Hansen et al. 2013). Very few of the forests potentially affected by threats from logging and oil palm production are protected under Category I and II levels by the IUCN (New 2016); FAO figures of oil palm plantation area in the country show increases by 72.3 % from 1989 to 2013, with 25.3 % stemming from deforestation (Vijay et al. 2016).
This species used to feature in the species trade. In the past, an imperfect male specimen of this species fetched as much as $2,850 (Collins and Morris 1985), leading to concern about wild populations and the hope that butterfly ranching would help to take the pressure off wild populations of this and other species of this genus (Parsons 1992). As a result of trading pressures, Ornithoptera alexandrae has been placed on CITES Appendix I in 1987 (with all other Ornithoptera, Troides and Trogonoptera listed on CITES Appendix II) (e.g., Collins and Morris 1985). As a result, trade is prohibited with the exception for scientific study. As a result, few records of import/export of specimens exist.
|Conservation Actions:||This species has been protected under the Faunal Protection Ordinace of 1966 law since 1966 (Haugum and Low 1979, Collins and Morris 1985), and it is listed on CITES Appendix I. This species was a priority species for conservation projects in New and Collins' (1991) action plan for the world's swallowtail butterflies. This suggested specifically the establishment of special reserves for this species and conservation planning for birdwing butterflies more generally across Papua New Guinea (New and Collins 1991). New (1997) reports on an international conservation programme funded jointly by the governments of Papua New Guinea and Australia which increases financial rewards to local people from already changed secondary forest habitat to limit the rate of destruction of primary forest. Butterfly farming has been suggested as part of the conservation plan for this species in the Popondetta region, to help provide landowners with an income alternative to oil palm plantations (Parsons 1992), although given the species' CITES Appendix I listing, trade is prohibited except for scientific purposes. There are a number of protected areas within the range of the butterfly, but it is unknown whether the species occurs within them (WDPA 2013). There has also been a call for a captive breeding facilitate for this species on the Higaturu Estate, near Popondetta (Mitchell et al. 2016). There is a need for more data on this species, specifically with regard to the status and trends of its population and the impact that threats may have on the species.|
|Citation:||Böhm, M. 2018. Ornithoptera alexandrae. The IUCN Red List of Threatened Species 2018: e.T15513A88565197.Downloaded on 17 August 2018.|
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