Digitising some of the most endangered butterflies on Earth | Digital Collections Programme

Guest blog by Peter Wing

The Birdwings butterfly collection contains many interesting specimens and species that have captured the fascination of naturalists over centuries including well known collectors Lord Walter Rothschild and Alfred Russel Wallace.

As collecting these specimens is now restricted under international law, these species have also come to the attention of HM revenue and customs and Wildlife Crime Units. I thought it might be interesting to touch on a few of these aspects to provide an insight into the history of the collection and how digitising these specimens can unleash a new online resource to the world and provide important data to help setting out conservation plans to protect these endangered species for the future.

Birdwings are named for their wing shape and size, and birdlike appearance in-flight. They are a group of the Papilionidae (swallowtail butterflies) comprising the genera Ornithoptera, Trogonoptera and Troides, which contain 36 species between them. The range of these species spreads from Southeastern Asia to Northern Australasia, with some species spreading to India in the west and others found in Northern Australia in the southernmost extent of their range.

All Birdwings fall under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES)  trading legislation, with Queen Alexandra’s Birdwing (Ornithoptera alexandrae) being one of only three insect species listed in the ‘most endangered’ category as assigned by The International Union for Conservation of Nature (IUCN).  As they are threatened with extinction, CITES prohibits international commercial trade in specimens of these species.

The method of imaging the specimens is virtually the same as for the Madagascan Lepidoptera Type Project. This includes imaging from the top (dorsal),underside (ventral) of the adult specimens and labels and of all the immature stages, the eggs, larvae and pupae.  However, unlike with other specimens, it has been easier to move the digitisation set up to the collections’ area for this project as opposed to bringing specimens to the regular digitisation space. In contrast with recently curated parts of the Lepidoptera collection, which are housed in plastazote lined wooden drawers with a glass top, the Birdwings’ collection have been kept in the original Rothschild collection drawers with glass both above and below. This enables scientists to see both the top and bottom of these exquisite specimens, but does make transporting them that much more difficult.

These specimens are so large in comparison to other Lepidoptera we’ve digitised and, in some instances, incredibly fragile, that it takes much longer to complete the imaging and ensure that no specimens are damaged during the process.

Queen Alexandra’s Birdwing (Ornithoptera alexandrae)

Queen Alexandra’s Birdwing, described by Lord Walter Rothschild and named to honour the Queen consort Alexandra, the wife of Edward VII, is the biggest in size and possibly the most charismatic species of the birdwings.  There are marked differences between the males and females in this species is as can be seen in the images below. It is also the largest butterfly in the world with females having a wingspan exceeding 28cm. Discovered by A.S. Meek in January 1906, he stated the type locality in his 1913 book A naturalist in Cannibal Land as ‘Biagi, about 5000 feet high, at the head of the Mambare River.’

Ornithoptera alexandrae type specimen collected by A.S.Meek and described by Walter Rothschild in 1907.

This specimen was shot in order to be collected, which accounts for its perforated condition. This was noted by Meek in correspondence to Karl Jordan written held at the Museum (Meek correspondence, Letter 155), ‘Enclosed is female of large Ornithoptera shot by me on way up only two days from coast. This one is a small specimen, mostly running much larger. Females seem to be not too uncommon …’. Shooting the specimen was most likely necessary due to adults of this species normally being found within the rainforest canopy, inaccessible to collectors, and to the size of these butterflies which makes them feasible to hit.

Male Ornithoptera alexandrae specimen also collected by A.S.Meek

Not only are the females much larger than the males but as well as the stark difference in colour and patterning of the wings and abdomen, the wings of the male are narrow and elongate in comparison to the broad, rounded wings of the female.  

The range of this species is entirely restricted to the Northern province of Papua New Guinea. This has led to the species becoming part of the Northern, or Oro province flag which features a female Queen Alexandra’s butterfly.

Wallace’s Golden Birdwing (Ornithoptera croesus)

Although the Queen Alexandra’s Birdwing had not been discovered during his time in the Malay Archipelago, Alfred Russel Wallace wrote at length about birdwings, particularly within his paper ‘On the phenomena of the variation and geographical distribution as illustrated by the Papilionidae of the Malayan region’ (1865). It is his notes in The Malay Archipelago (1869) on first collecting Ornithoptera croesus , however, a species he described in 1859 and now bearing the common name Wallace’s Golden Birdwing, that show the great effect this species had on him upon him.

‘The beauty and brilliancy of this insect are indescribable, and none but a naturalist can understand the intense excitement I experienced when I at length captured it. On taking it out of my net and opening the glorious wings, my heart began to beat violently, the blood rushed to my head, and I felt much more like fainting than I have done when in apprehension of immediate death. I had a headache the rest of the day, so great was the excitement produced by what will appear to most people a very inadequate cause.’ Alfred Russel Wallace (1869)

While Wallace was clearly enthralled by this first sighting, we are not sure exactly which specimen he is referring to in his book. Phillip Ackery notes in ‘The Natural History Museum Collection of Ornithoptera (Birdwing) Butterflies (Lepidoptera: Papilionidae)’ (1997) that ‘it is frustrating that the available labelling gives no indication as to which (if any) of these specimens might have been involved in Wallace’s account’.  

Rajah Brooke’s Birdwing (Trogonoptera brookiana)

As well historically and scientifically  important specimens, there are those within the collection that are more modern and tell a completely different story, like this specimen of Rajah Brooke’s Birdwing (Trogonoptera brookiana)

The only data associated with this specimen, and an additional two drawers of specimens that bear the same information, is that it was ‘Confiscated by Customs & Excise. 15.viii.1980. Possible origin Malaysia B.M. 1981-183’.

All Birdwings are now CITES protected. Since 1975 their trade has been restricted which, after confiscation by Customs and Excise, is how these specimens came to be a part of the Museum collection in 1981.  Unfortunately the primary data of these specimens is virtually nonexistent. A ‘possible origin of Malaysia’ is of little use to scientists who need to know when and where this butterfly was collected in order to understand species range at specific times in history. Labels that contain good geographical data and dates can be transcribed and the information released onto the Museum’s data portal. These butterflies are protected from trading, but they are still  threatened by the encroachment of deforestation and agriculture on the areas in which they live. Data about these species can be used to help plan land use and support the conservation of these species for the future.

While the data surrounding endangered species is sensitive and should be treated with care and consideration, contemporary locality data on Birdwing species are already widely available in various scientific publications, and there are also research and other benefits to data release. Therefore the Natural History Museum consider that on balance, it is appropriate to make this data publicly available via the Museum’s Data Portal.

Experience the beautiful birdwings

The digitisation of the Birdwing butterflies has been possible due to the support of an anonymous donor. As part of this project, a display of Queen Alexandra Birdwings has been developed and will be on display at the Natural History Museum at Tring, alongside images of letters between Karl Jordan and Alfred Meek. This display opens on 24 January 2019 and will be on display for 12 months as part of the 150th anniversary of Walter Rothschild’s birth.

In addition to the Queen Alexandra specimens being available to visitors to Tring for the next twelve months, all the images and data for specimens that have been part of this project will be released via the Museum’s data portal and permanently join the 4.2 million collection specimens that have already been released.

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