Here we are, at the beginning of 2009. And here’s where I get that horrible feeling that – on the ‘things to do for 2008’ list – so many things remain incomplete. Among these are a number of Tet Zoo posts that were cutting-edge and topical when I started them, yet are now not so cutting-edge, and not so topical. Whatever: here’s a brief article I’d planned to publish months ago. It concerns the Bulo Burti boubou Laniarius liberatus, a bush-shrike described in 1991 on the basis of a single individual captured in central Somalia (Smith et al. 1991) [adjacent photo © E. F. G. Smith]. Bush-shrikes, or malaconotids, are an entirely African group of passerine birds. Unlike the more predatory shrikes (with which bush-shrikes were conventionally allied: they seem instead to be closer to vangas, ioras, helmet-shrikes and so on), bush-shrikes glean under-storey foliage, superficially recalling gigantic warblers.
During the early 1990s, the Bulo Burti boubou appeared in headlines all around the world. Whereas the type specimens of new species are usually dispatched and placed in museum collections, the Bulo Burti boubou was the first avian species in which the type specimen was released, alive. Edmund Smith (the lead author on the 1991 description) had initially (in 1988) seen this bird – that is, the one individual that became the type specimen – in the grounds of a hospital in Bulo Burti. Unable to identify it, he was lucky enough to see it ‘on most of the weekly visits to the hospital grounds’ (Smith et al. 1991, p. 227). Faced with the possibility that here was a new species, known only from a single, live specimen, he consulted with others and decided to capture the bird, and to release it after collecting as much data as possible. This plan was beset by a few problems* but was ultimately successful: the bird was captured in 1989 and released in March 1990.
* A deep-frozen fresh blood sample was lost in the post, meaning that traces of dried blood had to be relied upon for DNA analysis. And civil unrest in Somalia meant that the bird and its carer (Jan-Uwe Heckel) had to leave the country. Heckel looked after the bird in Germany before returning it to Somalia in 1990. The Bulo Burti area remained unsafe, and was also, by now, devoid of suitable habitat, so the bird was eventually released in a different place, the Balcad Nature Reserve [diagrammatic pic of Bulo Burti boubou below from wikipedia].
Smith et al. (1991) argued that ‘in the case of a taxon suspected to be threatened with extinction, our approach makes diagnosis possible without collection’ (p. 227). In recognition of the type specimen’s release, the species name liberatus was ‘chosen to emphasize that the bird is described on the basis of a freed individual’ (Smith et al. 1991, p. 228). Here we come to an area of much argument. I personally don’t like seeing animals dispatched or ‘collected’ in the name of science: if, like me, you’re sentimental and (try to be) ethical, you may find your personal feelings getting in the way of things when you’re out in the field and someone wants to kill an animal ‘for science’. Furthermore, ‘collecting’ is often completely unnecessary and so very much at odds with the ‘leave nothing but footprints’ mantra some of us would like to live by in these times of ‘eco-footprint’ awareness. In the case of the Bulo Burti boubou, its possible status as highly endangered contributed to the decision that it might be wrong to kill it (see Collar 1999). The same argument arose after the holotype of the endangered Tanzanian shrew Crocidura desperata Hutterer et al., 1991 was ‘collected’.
However… there are – in reality – usually enough animals for scientific collection to make no difference whatsoever (Patterson 2002). And, leaving personal feelings aside, most zoologists who have gone on record have argued that the collection of type specimens really is essential (and note that my sentimental objections above refer more to just ‘general collecting’ rather than to the specific procuring of TYPE individuals). Releasing such individuals (or failing to collect them) creates problems given that we lose – and/or lack – essential information, and lack the chance to go back and check the relevant specimens again (Banks et al. 1993, Bates et al. 2004, and see comments here). We looked at this debate back in 2006, when the Kipunji Rungwecebus kipunji was named (go here on ver 1. Pic of live kipunji shown here). The holotype was a live animal, photographed in the field (however, specimens were obtained later on). Type specimens were also not collected for the Blond capuchin Cebus quierozi Mendes Pontes & Malta, 2006 and Arunachal macaque Macaca munzala Sinha et al., 2005 (is it a coincidence that these are all primates?). As Collar (1999) pointed out, this is not necessarily a totally new thing however: during the 1800s, both P. L. Sclater and Walter Rothschild described new taxa on the basis of live, captive birds, and Delacour and Jabouille’s 1931 description of the Imperial pheasant Lophura imperialis was based on live specimens.
The scientist in me concludes that the collection of actual, physical type specimens (= dead animals) is indeed a necessity: we need such specimens to demonstrate the absolute reality of a taxon. Claims that taxon x is a hybrid or variant can at least be checked against a specimen if it exists in a collection (see the case studies in Bates et al. (2004)), whereas they can’t if the thing is out and running round in the wild. And we need to know that taxa are ‘real’ before we can pin hypotheses on them, or compose conservation strategies for them. At the far extreme end of the spectrum, the existence of controversial animals – like a new mega-mammal, say (yes, I’m thinking of sasquatch) – could only ever be demonstrated by the collection of a body or bodies, as in such cases no amount of scat, hair, DNA, or photographic data would ever definitely be good enough.
As some have said, this issue does seem to boil down to sentiment vs science. I can readily admit that my sentimental feelings get in the way of my views on killing animals, but then that’s ok because I’m not out there, trying to catalogue new, extant fauna.
You may, by now, have realised that I’ve gone off at a tangent. The original point of this article was to draw attention to the fact that the species-level status of the Bulo Burti boubou was challenged in 2008. Nguembock et al. (2008) analysed the molecular phylogeny of 41 Laniarius species and subspecies, producing the first densely-sampled analysis of this taxon (but, note, NOT the first molecular analysis of Laniarius).
They found that the Somali boubou, traditionally regarded as a subspecies of L. aethiopicus and known as L. a. erlangeri, did not group with the rest of L. aethiopicus (or with its closest relatives). Instead it was out on its own, possibly being most closely related to the Red-naped bush-shrike L. ruficeps [shown here, photo by Nik Borrow, from here]. Accordingly, Nguembock et al. (2008) recommended that its original species name, L. erlangeri Reichenow, 1905, be resurrected.
And what of L. liberatus, the Bulo Burti boubou? This was found to cluster with L. erlangeri and thus to be synonymous with it, so: goodbye L. liberatus. Perhaps. Nguembock et al. (2008) only said that the one known specimen ‘is identified as an unusual colour morph [of] L. erlangeri‘, but they otherwise provided little discussion. That seems a bit weird given that ‘Molecular data reveal L. liberatus synonymous with L. erlangeri‘ looms large in the title of the paper.
Refs – –
Banks, R. C., Goodman, S. M., Lanyon, S. M. & Schulenberg, T. S. 1993. Type specimens and basic principles of avian taxonomy. Auk 110, 413-414.
Bates, J. M., Bowie, R. C. K., Willard, D. E., Voelker, G. & Kahindo, C. 2004. A need for continued collecting of avian voucher specimens in Africa: why blood is not enough. Ostrich 75, 187-191.
Collar, N. J. 1999. New species, high standards and the case of Laniarius liberatus. Ibis 141, 358-367.
Nguembock, B., Fjeldså, J., Couloux, A. & Pasquet, E. 2008. Phylogeny of Laniarius: molecular data reveal L. liberatus synonymous with L. erlangeri and “plumage coloration” as unreliable morphological characters for defining species and species groups. Molecular Phylogenetics and Evolution 48, 396-407.
Patterson, B. D. 2002. On the continuing need for scientific collecting of mammals. Journal of Neotropical Mammalogy 9, 253-262.
Smith, E. F. G., Arctander, P., Fjeldså, J. & Amir, O. G. 1991. A new species of shrike (Laniidae: Laniarius) from Somalia, verified by DNA sequence data from the only known individual. Ibis 133, 227-235.