extinct – More Than A Dodo

By Eileen Westwig, Collections Manager in the Museum’s Life Collections.

About 320 km south of Java in the Indian Ocean lies Christmas Island. Although discovered and named on Christmas Day in 1643, the island remained unexplored until its first settlement in 1888, a development which had dire consequences for some of its native species.

Christmas Island is home to a variety of endemic animals such as rats, land crabs, butterflies and many birds. The accumulation of bird droppings over thousands of years made the island rich in phosphate, and the commercial potential of these deposits brought many expeditions to the island. With the ships’ cargo came black rats.

Two species of endemic rats, Maclear’s Rat (Rattus macleari) and the Bulldog Rat (Rattus nativitatis) went extinct within 20 years of settlement, despite having been previously very numerous on the island.

One of the skins of Maclear’s Rat (Rattus macleari) collected by H.E. Durham, and now held in the Life Collections of the Oxford University Museum of Natural History.

Maclear’s Rat, seen at the top of the page in an illustration from an 1887 publication, was described as chestnut brown above, with a partly white, long tail. It was once the most numerous mammal on the island ‘occurring in swarms’. The Bulldog Rat had a much shorter tail and a layer of subcutaneous fat up to 2 centimetres thick, the function of which is unknown to this day.

The likely cause of their extinction was the introduction of diseases by the ship rats, to which the Christmas Island rodents had no immunity. The disappearance of the native rats also had a knock-on effect: the parasitic Christmas Island Flea (Xenopsylla nesiotes) depended on the rats as hosts, and so the fleas became extinct with the rats’ demise.

In 1901 Dr. Herbert E. Durham, a British parasitologist investigating the origins of beriberi disease, led an expedition to Christmas Island. During his visit he collected several specimens of Maclear’s Rat, but was unable to find any Bulldog Rats, despite a lengthy search and the offer of a reward. Two of the nine Maclear’s Rats Durham obtained showed abundant parasites, trypanosomes, in their blood.

Christmas Island possesses quite a number of peculiar species in its fauna, and it is regrettable that observations were not made before animals had been imported to this isolated station, as well as that my own notes are so incomplete.

Dr. Herbert E. Durham

Durham also found blood parasites in the native fruit bats (Pteropus melanotus) but noted that these were unlikely to have been introduced, instead were “an old standing native occurrence.” These bats still inhabit various islands in the Indian Ocean, including Christmas Island, where they are critically endangered.

Original letter by H.E. Durham offering his Christmas Island specimens to the Museum in 1938.

The Museum holds a range of material from Christmas Island, including six skins and three skulls of Rattus macleari, which were collected by H. E. Durham in 1901-02, and donated in 1938.

Visit the Museum’s Presenting… case between now and 6 March to see Christmas Island specimens from the collections.

Deal or no deal

by Darren Mann, Head of Life Collections

In a previous article on this blog I reported the discovery, in an insect collection, of the 21st British specimen of the ‘Regionally Extinct’ dung beetle Melinopterus punctatosulcatus. And since then, I’ve been on the hunt for more…

Heading out to numerous other museum collections I discovered more specimens, all collected in the same locality – Deal in Kent. In Ipswich Museum there are six, collected by C. Morley in 1896; there are two in the Natural History Museum, London, collected by G.C. Champion; and in the Museum of Zoology, Cambridge there are two collected by G.C. Hall in 1883.

But the earliest and most recent finds are both in the National Museum of Scotland – one from May 1871, in the G.R. Waterhouse collection, and one from 1923, in the T. Hudson-Beare collection. So now we know of 42 specimens of this beetle with data and we know that the species occurred at Deal for about 50 years. But why are there no records after this time?

The Deal sandhills in Kent were famous for their insects, but even as long ago as 1900 entomologists* were discussing the negative impact of “summer camping-out stations and the modern craze for the ‘Royal and Ancient Game of Golf'” on beetles and butterflies in the area.

Today, most of the sandhills are gone and there are no grazing animals other than a few rabbits. Most of the surrounding land is either developed as a golf course or under agricultural management. So, is the possible local extinction of this dung beetle due to habitat loss and a lack of dung?

To try and answer this question, naturally I went looking for poop in Deal. In a field in Sandwich Bay I could hear sheep bleating in the distance, although poo was scarce. Eventually I found a few old plops and inside were ten Calamosternus granarius, a small dung beetle. This was good, but my main target was Melinopterus punctatosulcatus.

Melinopterus punctatosulcatus edit — A specimen from the Museum of *Melinopterus punctatosulcatus,* previously listed as ‘Regionally Extinct’ in Britain, but now rediscovered in Deal, Kent

I probed the poop further. To my delight, crowded in the remaining squishy bit were four other species. On close inspection, one of these was hairy, so a male, and much darker than its close relatives. It fitted perfectly with my expectations for Melinopterus punctatosulcatus after seeing so many examples in museum collections. Success! This beetle, misidentified in museum collections for so long, and not seen since the 1920s in Deal, is indeed hanging on in Kent.

Disappointingly, after a further few days of searching, only a handful more specimens were seen. This suggests that either the species exists at low population levels, or that it was it was not the peak emergence period when I was there. Nonetheless, a species not recorded anywhere in the UK for over 70 years is actually still here.

Now hopefully we can encourage local land owners to help conserve this all-important dung fauna and flora.

* Walker, J.J. 1900. The Coleoptera and Hemiptera of the Deal Sandhill. Entomologist Monthly Magazine 36: 94-101.

Tag: extinct

Presenting… Christmas Island

Deal or no deal