Category: flowers

The Race: Taming of the Shrew (and updates)

Things have been very busy.

Our flower people, Dr. Tom Daniel and Rebecca Wenk have been very active. Rebecca successfully completed her M.Sc . degree at San Francisco State University, based in part on plants she collected in the islands during GG III (A). She then published her research, with Tom, in the latest Proceedings of the California Academy of Sciences; the publication includes a special treatment of the genus Elytraria – E. mariginata is the little flower that Rebecca finally found high up on Pico Papagaio on Príncipe that was so exciting and which we reported last May. (See “News from the Flower people”).

Rebecca among the giant Begonias. Lagoa Amelia. Wenk camera: GG III.

Tom is nearing completion of his monograph on the acanthus (shrimp) flowers of São Tomé and Pr<!–[if gte msEquation 12]>í<![endif]–>ncipe. He is now collaborating with Estrela Figueiredo, a Portuguese botanist who has been on the islands many times and has added much to our knowledge of the botany of the Gulf of Guinea as a whole There are several species of the Acanthaceae found only on São Tomé and Príncipe and one (Heteradelphia paulowilhelmia) which may be endemic at the genus-level. We found this beautiful flower in the middle of Lagoa Amelia at 1400 m. during GG III.

Heteradelphia paulowilhelmia. Lagoa Amelia. Weckerphoto: GG III

Wes Eckerman (photographer) Rebecca and Tom at Lagoa Amelia. RCD phot: GGIII

Another species in Tom’s group that is of particular interest to me personally is an acanth called Justicia thomeensis. This flower is known only from São Tomé and has not been collected since the late 19th Century – the original collector did not provide detailed locality data, and we have not found it on the islands yet. We hope it is not extinct, or that it was not actually collected somewhere else. Tom has examined the original dried specimens in Coimbra; it is perfectly valid, and he is re-describing the species. Another botanist named Hedrén examined this material, and in a 1989 study found that J. thomeensis is more closely related to a group of species in East Africa than to any in nearby West Africa. I am finding the same strange disparate distribution patterns among my island frogs.

Justicia relationships. RCD

On the crustacean front, Alex Kim, our freshwater shrimp colleague (see January and March blogs) has decided to attend Harvard for his undergraduate studies, and this summer he is doing fieldwork on prawns in Puerto Rico. He tells us that the São Tomé specimens collected for him earlier this year by the marine group “..represent at least two species which, based on morphology, have clear affinities with New World forms. DNA analysis is still ongoing, but the geological youth of these prawns leads me to suspect that we will soon have genetic evidence of trans-Atlantic larval dispersal.” Pretty impressive stuff for an incoming freshman.

A New World prawn.  Alex Kim phot.

A few months ago I had an opportunity to lecture on some of the scientific results of our Gulf of Guinea Island expeditions to a group of biologists at international meetings in Sardinia; afterward in Spain, I met one of the foremost experts on bats, Javier Juste, of Institute Doñana in Seville who has also worked on the islands and has discovered some of the same strange evolutionary relationships that we have. We are about to send him bat tissues from our GGI collection for DNA extraction.

7th Congresso Nazionale, Societas Herpetologica Italica. Sardinia. C. Corti phot.

In earlier blogs, we discussed the fact that mammals make poor dispersers over saltwater barriers; except for some bats, mammals simply cannot survive long enough to colonize oceanic islands. This is because we mammals have to eat regularly in order to maintain constant body temperatures –without “stoking the furnace” by eating regularly, mammals quickly die of exposure. This is specially the case with shrews; because of the ratio of their tiny body masses to their surface area, shrews lose heat faster than any other mammal, and a shrew has eat almost constantly, or it dies of hypothermia. It is perhaps a testimony to the great geological age of São Tomé and Príncipe that shrews appear to have, nevertheless, successfully colonized both islands! If the two species are indeed valid and occur naturally (not brought to the islands accidentally through human agency), then these may be the only oceanic island shrews in the world.

The Sao Tome shrew (Crocidura thomensis). R. Lima phot. 2009

To our knowledge, the photographs above and below are the first ever published of the supposedly endemic São Tomé shrew, Crocidura thomensis. The photographs were taken by Ricardo Lima, a doctoral candidate at the University of Lancaster who is studying the environmental effects of various agro-forestry techniques on São Tomé. Ricardo tells us that the shrews are not at all rare; in spite of this, we don’t know much about this little critter, nor the one on Príncipe. The São Tomé species was first discovered in 1886 by the great Portuguese explorer, Francisco Newton and described in 1887.

C. thomensis. R. Lima phot. 2009.

The relationships of these small island insectivores were not assessed until nearly 100 years later by Heim de Balsac and Hutterer in 1982. These authors concluded (on morphological evidence) that the São Tomé shrew was a full endemic species, and that the Príncipe form was an endemic subspecies of Fraser’s musk shrew (C. poensis) which is widespread on mainland Africa.

Ricardo Lima and friends, crossing the Rio Lemba, Sao Tome.  2009.

Now, we are in the exciting position of being able to test these assumptions using modern genetic techniques; just how closely related are the two shrews, based on DNA sequence? Did these mammals arrive naturally by rafting, as we suggest for the amphibians? Perhaps millions of years ago? Or were they hitchhikers on an old Portuguese galleon a couple of hundred of years ago? We hope to find out.

Aspergillus dykowskii and Sarophorum palmicola on monkey pod cacao; Lagoa Amelia. D Lin phot. GG II

Finally, our mycologists have a huge job. As you know before our expeditions began back in 2001, there were only four species of mushrooms known from São Tomé, and Príncipe had never been sampled. Now, after Dr. Dennis Desjardin’s work on GG II (2006) and his subsequent return with Dr. Brian Perry during GG III last year, we now have 225 species (including 75 listed for the first time on Príncipe). Many of these are probably new to science and it will be a major effort to fully analyze the entire collection. But Dennis and Brian took the opportunity to describe one of the new species separately. It has just been formally published in the journal Mycologia, and they have named it after me! It is a weird looking thing, and I will describe the whole process (including the humor sometimes involved) in the next blog.

Here’s the parting shot:

“After the Race.”  Weckerphoto. GG III

PARTNERS

We gratefully acknowledge the support of the G. Lindsay Field Research Fund, Hagey Research Venture Fund of the California Academy of Sciences, the Société de Conservation et Développement (SCD) for logistics, ground transportation and lodging, STePUP of Sao Tome http://www.stepup.st/, Arlindo de Ceita Carvalho, Director General, and Victor Bomfim, Salvador Sousa Pontes and Danilo Bardero of the Ministry of Environment, Republic of São Tomé and Príncipe for permission to export specimens for study, and the continued support of Bastien Loloumb of Monte Pico and Faustino Oliviera, Director of the botanical garden at Bom Sucesso. Special thanks for the generosity of private individuals, George G. Breed, Gerry F. Ohrstrom, Timothy M. Muller, Mrs. W. H. V. Brooke and Mr. and Mrs. Michael Murakami for helping make these expeditions possible.

The Race Goes on: News from the Flower People

As I mentioned yesterday, the first two botanists to join one our GG expeditions are Dr. Tom Daniels of CAS Botany Department and one of his graduate students, Rebecca Wenk. Both are specialists on a large family of tropical herbs called the Acanthaceae. Can’t give you a common name, sorry.
Dr. Tom and Rebecca among the Lagoa Azul baobabs, Sao Tome

Rebecca and Tom among the baobabs at Lagoa Azul. Weckerphoto

GGIII.
There is already a book on the flora of the islands written by a man named A.W. Exell many years ago but there are still many groups that are poorly known on Sao Tome and Principe, including Tom’s and Rebecca’s acanths, and there is always the possibility of finding something new. Although these data are old, it is estimated that the flowering plants of Sao Tome and Principe are between 8 and 14% endemic, found nowhere else in the world. The numbers are a range because it depends upon which island and plant family you are talking about, but the endemicity is high.
A fly visits one of Tom's Principe acanths

Brillantasia, Sao Tome. Weckerphoto, GGIII
Tom and Rebecca have been working side by side with the cugumelo team but have been pressing and drying their plants at the small herbarium at Bom Sucesso, which is at about 1000 meters on the island of Sao Tome. The herbarium and delightful botanical gardens of Bom Sucesso were first built with support by ECOFAC, but now run by a local NGO called Monte Pico; their specialty is the endemic orchids, and there are guides for tours of the gardens, as well as guides available for hikes up into the “real” primary vegetation above. Our old friend, Bastien Loulomb, has been an advisor to Bom Sucesso and Monte Pico for a long time and has been of consistent help to me on the GG II and GG III expeditions.
a guide, Dennis, Bastien, Bob, Rebecca, Brian, Tom

GGIII team at Bom Successo, Sao Tome. Weckerphoto GGIII
I have always teased my botanical colleagues about the funny hats they wear in the field, and the fact that they never seem to get dirty like us herpetologists. Well, funny hats are a given (see the photo) but Tom and Rebecca get just as dirty as the rest of us. So far they seem to have collected whole samples, tissue for DNA and for karyotyping of all of the known endemics of their group, but have also collected great samples of a lot of other peculiar things, including the world’s largest Begonia, B. ebaccata, which grows to nearly 10 meters on Sao Tome. All duplicates collected by our botanists will reside at Bom Sucesso in the Herbarium.
The worlds largest Begonia, B. ebaccata, endemic to Sao Tome

Begonia baccata, largest in the world – Lagoa Amelia, Sao TomeWeckerphoto, GGIII

Tom on the hunt

Tom at Bom Successo. Weckerphoto GGIII
A high point was when Rebecca finally found an example of her “questing beast,” a tiny little acanth growing along the side of track up Pico Papagaio on Principe. She let out a loud shriek and dove to the ground. I wish I could remember the name of the thing, but Tom and Rebecca are on there way back the US as I write. Apparently, she needed sequence data from this little plant critter in order to “root the tree” of her current MSc thesis (the scientists among you will understand). Here’s a photo of her with her discovery.
Rebecca finds her critter!! on Principe Island

Rebecca Wenk with her “questing beast.” Weckerphoto GGIII

Rebecca's critter (an acanth of course), Principe

Rebecca’s acanth crittter (Elytraria marginata).  Weckerphoto, GGIII

Finally, thanks to SCD a couple of weeks ago, we were offered a boat ride to the inaccessible southwest coast of Principe The southwest exposures of all of the islands in this chain, Bioko, Principe, Sao Tome and Annobon are inaccessible by land because they receive the brunt of the incoming weather, hence erosive force comes from the southwest. For the same reason the Portuguese were unable to cultivate these areas during their 500 years of colonization here and on each island these exposures are pretty much untouched by man. In one sense the trip was a near disaster; our small rubber dingy flipped and a lot of our equipment was compromised, most of it temporarily. But the mushroom guys were able to collect a bunch of stuff on a virtually untouched steep slope, and Tom and Rebecca were able to establish that the dominant plant group in the southwest of Principe is the Rubiaceae, members of the coffee family.
A Principe mellistome

A melastome from Sao Tome.  Weckerphoto GGIII
An acanth in the Contador Valley, Sao Tome

We are posting a bunch of images, mostly by Wes Eckerman, that are unlabeled. The reason for this is that in many cases we do not know yet what the stuff is. Stay tuned.
A fisherman in Lagoa Azul

Fisherman at Lagoa Azul. Weckerphoto GGIII

PARTNERS We gratefully acknowledge the support of the Research Investment Fund of the California Academy of Sciences, the Société de Conservation et Développement  (SCD) for logistics, ground transportation and lodging, STePUP of Sao Tome http://www.stepup.st/ and especially the generosity of three private individuals, George F. Breed, Gerry F. Ohrstrom and Timothy M. Muller, for making GG III possible.
Next will be posting on my stuff, the creepy crawlies.