The Race: New Species or What’s in a Name?
Category: Biodiversity, Sao Tome, frogs, mushrooms, shrews | Date: Aug 18 2009 | By: islandbiodiversityrace
Ever wonder why biologists use weird, hard-to-pronounce names for animal and plant species? Well, it all started with Carl Linnaeus, the famous Swedish 18th Century botanist pictured below.
In the 10th edition of his great work, Systema Naturae (1758), Linnaeus established a system wherein every living species is given but a single scientific name made up of two parts: the Genus (always capitalized) and the species (always lower case and both are always italicized). Among animals, no two species ever have the same name, and this is true among plants, as well. Thus we modern humans are scientifically referred to only as Homo sapiens. In Linnaeus’s day, most scientists wrote in Latin or Greek, thus it was an early tradition to establish these names in those ancient languages. Now, naming of new species is tightly regulated by The International Congress of Zoological Nomenclature (ICZN; the botanists have the ICBN). A specific scientific name avoids confusion… here is an example:
The common English name of the critter above is red rattlesnake, or red diamondback rattlesnake; some locals might call it a “red buzzworm!” In French it would be called un serpent á sonnettes rouge; in German: eine rote klapperschlange and if an East African ever saw one, he might call it nyoka sumu nyukundu. See the problem? Not only different base languages, but regional differences in common names serve to muddy the waters. However, the scientific name of this critter is Crotalus ruber, and regardless of their native languages, scientists will always know exactly what species is being discussed. Taxonomists usually try to come up with a name that is descriptive of the species; in this case, Crotalus ruber translates roughly from the Latin as “red bell-ringer,” an obvious reference to its color and the sound made by the rattle.
The Sao Tome shrew: Crocidura thomensis (R. Lima phot, 2009)
Here is another example– the supposedly endemic shrew we are just beginning to study is called Crocidura thomensis, which means “yellow-tail from Thomas [=São Tomé]”. Probably the first species described in the genus Crocidura had a yellowish tail, although C. thomensis clearly does not.
The Oceanic Treefrog, Hyperolius molleri (Weckerphoto GG III)
Scientists may also name species in honor of the person who first collected the specimen; such is the case with the Oceanic treefrog, Hyperolius molleri, found on both São Tomé and Príncipe, M.A.F. Moller was the late 19th Century explorer who first collected the frogs and brought them to Portugal where the species was named in his honor at the University of Coimbra.
Sao Tome puddlefrog, Phrynobatrachus leveleve (Weckerphoto GG III0
Taxonomists have a fair amount of latitude in the choice of words and meanings for scientific names although they are usually Latinized. As an example, Josef Uyeda, Breda Zimkus and I chose Phrynobatrachus leveleve as the new name for one of our own new species of frogs from São Tomé. Phrynobatrachus is an old generic name and actually means “toad-frog;” as to the meaning of leveleve, here is a quote from our paper: The phrase, “leve leve,” generally meaning “easy, easy” or “lightly, lightly” has also been translated by Henrique Pinto da Costa, former Minister of Agriculture, as “calmly, surely.” In our opinion, all three definitions describe the delightful, easy-going demeanor of the citizens of The Republic of São Tomé and Príncipe….it is with the hope that the citizens of this tiny African nation will maintain their ecological heritage and cheerful outlook on life that we name this diminutive endemic anuran. Thus, we named the new species in honor of the attitude of the island citizens.
Illustration by H. Heatwole, 1970
Scientists are also known to inject humor into scientific names, on occasion. The image above is a composite plate from a scientific publication. By way of explanation, many American scientists receive support for their work from our National Science foundation, known universally to us over here as “NSF”. Look at the upper-most image of a frog known scientifically as Physalaemus enesefae… if you are an English speaker, pronounce the species name slowly and you’ll get the humor.
Now for the fun stuff: here is a photo of our latest new species from São Tomé, a mushroom we discovered on the trail up to Lagoa Ameliaduring GG II in 2006. It was formally described just last month in the journal MYCOLOGIA, and Drs Dennis Desjardin and Brian Perry named it after me. It is called Phallus drewesi meaning (literally) Drewes’s penis!
Phallus drewesi Desjardin & Perry 2009 (B. Perry phot. GG III)
As you can see, these fungi are shaped very much like a mammalian penis… they usually grow upright from the forest floor, smell terrible and attract flies! The flies act as vectors disperse the fungus’s spores!
Dr. Brian Perry with a Principe Phallus (RCD phot. GG III)
Members of the genus Phallus can grow quite large. Above is an image of Dr. Brian Perry, one of the describers, holding an example of Phallus atrovolvatus from Príncipe –a rather average sized Phallus.
The author with Phallus drewesi on Sao Tome (Weckerphoto, GG III)
Above is a picture of me holding a couple of examples of Phallus drewesi in 2008, and as you can see, they are quite small! Not only that, but so far as is known P. drewesi is the second smallest species in the world! And, it grows limp! Not proudly erect from the forest floor!
It has been hard for some of my non-scientists to understand what an incredible honor this is. Dennis, Brian and I are good friends and colleagues; in fact, Dennis and I play jazz together as often as we can and serve on the same university faculty.
The author and Dr. Desjardin at Praia Francesa. (Weckerphoto GG III)
It is a great honor because having a species named for you confers a form of immortality. Regardless of what the species is, the scientific name lives on as long as there is science. This is even the case even if decades from now, another scientist learns that this species already has a name – Phallus drewesi lives on in the botanical literature as a synonym. Scientists keep track of all names formally ascribed to a species, whether valid or not. So, yes, it is a wonderful thing to have something named after you, whatever it may be!
Here’s the parting shot:
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: New Fish Excitement
Category: Biodiversity, Gulf of Guinea, Island endemics, Sao Tome, fish, principe | Date: Jul 09 2009 | By: islandbiodiversityrace
Our colleague, Ricardo Lima, currently working on São Tomé has sent us another exciting photo; not of another São Tomé shrew this time, but of a large fish that we somehow missed during the island river surveys of GG I and GG II.
Led by Dr. Tomio Iwamoto, we surveyed all of the major rivers on both São Tomé and Príncipe in 2001 and 2006. As a result, Drs. Iwamoto and Petzold published a paper on the freshwater gobies of the islands, and later Dr. Iwamoto was one of the authors of the updated Checklist of Coastal Fishes of São Tomé and Príncipe Islands. This checklist is based on a great deal of our expedition material. Regardless, the fish that Ricardo has photographed was not included in either work and at the moment we have no idea to which species it belongs.
“Charroco“ R. Lima phot. 2009.
Quintino Quade and Dr. Iwamoto on Sao Tome. D. Lin phot. GG I
It is a fairly large fish and well-known by the local Sao Tomeans as “charroco ” Ricardo tells us, “I was told by an old man that lives in S. Jose (Binda), that he used to fish these upstream. But this photo is from the other [east] side of the island, near EMOLVE, the big oil palm plantation! I’m not sure where they got the animal, but I think it’s widespread, and according to the people who fish them, it lives in holes under the rocks. The specimen I photographed is not very big for the species. According to them, it can get much bigger, but they eat even the small ones, deep fried!”
Tomio and Drewes on Principe. D. Lin phot. GGI
Dr. Iwamoto has sent Ricardo’s photo to two other experts, Dr. Lynne Parenti of the US National Museum and Dr. David Greenfield of Monterey, California, and both agree that this is probably a member of the Family Eleotridae, or “sleeper gobies”. During our surveys, we caught other species of this family, one of which is pictured below; but at the moment, we seem to have another unidentified species from the Gulf of Guinea and will have to work to obtain more material and identify it.
A Sao Tome eleotrid fish. RCD phot. GG I
The Parting Shot:
A beach on north Principe. R. Wenk phot. 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: Taming of the Shrew (and updates)
Category: Biodiversity, Gulf of Guinea, Island endemics, Sao Tome, biogeography, flowers, mushrooms, principe, shrews | Date: Jun 24 2009 | By: islandbiodiversityrace
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.
Within the House of Slytherin (II. some snakes)
Category: Biodiversity, Sao Tome, biogeography, snakes | Date: May 05 2009 | By: islandbiodiversityrace
Snakes are not great over-ocean dispersers; they are certainly better than frogs or freshwater fish but not as successful as spiders, geckos and skinks. For instance there are no native snakes in the Hawaiian Islands although they do occur in the Galapagos, but these are much closer to a source continent. In spite of their small size and isolated nature, São Tomé and Príncipe have a rather surprising snake fauna; there are at least seven species, five of which we know to be endemic - they are found nowhere else. This group includes three species of “lower snakes” or scolecophidians; these are small, blind burrowing forms, two of which are endemic to São Tomé and one to Príncipe.
Rhinotyphlops newtonii, a burrowing scolecophidian from Sao Tome. (D. Lin phot. GG I)
The more advanced snakes (caenophidians) are represented by one endemic, diurnal (daytime) species on each island (belonging to two unrelated genera) and a nocturnal subspecies which is currently thought to be the same on both islands.
Hapsidophrys principis- (cobra sua sua:“snake fast”)- the endemic diurnal species of Principe (D. Lin phot. GGI).
The nocturnal snakes are known as cobra jita (“snake slow”). I have mentioned these in earlier blogs, and my suspicions are that the two island populations are distinct endemics—we are beginning a molecular study this summer to test this hypothesis.
Cobra jita (”snake slow”), the nocturnal species from both islands? (Weckerphoto. GG III)
But here I want to talk about the remaining snake found on São Tomé which the islanders call cobra preta (“snake black”); this is the only dangerous species on the islands, and it is a bit of a mystery to me.
The black and white, or Forest cobra - Naja melanoleuca. Ethnobiomed phot.
Widely distributed on the African mainland, this species is known as the forest cobra, or black and white cobra (Naja melanoleuca), and it is quite a venomous and formidable animal. In some parts of its range it can exceed 3 meters in length (10’).
Forest cobra distribution. map by Nils Boyson
Head of Forest or Black and White cobra, Naja melanoleuca.
This snake, like most true cobras, displays a hood as part of its defense system, essentially making itself look larger in order to warn of its presence. Like all members of family Elapidae, cobra preta has erect front fangs that are hollow and syringe-like, and it injects prey animals with venom that attacks the nervous system (neurotoxin).
[l.] C. melanoleuca fang showing aperture (Bruce Young) [r.] direction of venom injection (E. Jose)
All of the São Toméans know of cobra preta and fear it, although I have no idea how frequently citizens are bitten. Based on a dead-on the-road specimen at nearly sea level in the south of the island, we know it occurs in lowlands, but I suspect it is more common in the mid-level forests; during GG I, we purchased a number of skins from farmers at Bombaim, which is at middle elevation.
Dead on the road, south Sao Tome. (RCD phot. GG recon 2000)
Joel Ledford with Bom Sucesso specimen. (J. Ledford phot. GG I)
The 2- meter specimen above was killed by locals near the Botanic Gardens and Herbarium of Bom Sucesso at about 1000 m, and we were able collect it during the GG I expedition.
During GG II in 2006, we encountered a very large specimen while collecting along an aquaduct in the Contador Valley on the west side of the island at 700 m; in fact, several of us nearly stepped on it before we were aware of its presence.
On our most recent foray, GG III A, we were again on the Contador Aquaduct when a middle-sized snake was killed by locals around a bend in the road, less than 100 m from where we were working.
Contador Valley specimen (Weckerphoto GG III)
Regrettably, they had beheaded the specimen, and so it was of no value as a voucher specimen; however, we were able to photo-document the animal and I removed some liver tissue for future analysis.
Liver tissue removal. (Weckerphoto. GG III)
The presence of the cobra on São Tomé Island is widely considered to be the result of human introduction, most likely accidental (it is hard to imagine an individual bringing a deadly snake on purpose!). Physically it appears to be identical to the widespread Naja melanoleuca of the mainland. Accidental introduction makes ecological sense to me as well because the species does not really fit into this old ecosystem as we are beginning to understand it. We know that the other higher snakes feed on endemic prey species such as frogs and lizards. But aside from some birds, there do not seem to be endemic prey species that are of sufficient size to sustain a large, heavy-bodied snake like cobra preta; on the other hand, plenty of rats, chickens, etc. have been brought over by humans since the 15th Century.
Two of the top African cobra experts are Drs Wolfang Wuster of the University of Wales and Donald Broadley of Zimbabwe. They are currently working on this species, and we have been sending them our tissue samples for DNA analysis. Soon, we should know whether or not this large cobra drifted out to the islands on its own and has since been genetically diverging, or whether it was brought to the island through human agency. Wuster and Broadley are currently describing a new species from Ghana that was long thought to be the species Naja melanoleuca.
Our parting shot:
Roadside enterprise on Principe(Weckerphoto GGIII)
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 F. 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: Bad News/Good News
Category: Biodiversity, cacao, chocolate | Date: Mar 16 2009 | By: islandbiodiversityrace
I have some bad news (maybe) and some good news:
The image below is what might be our bad news. During GG III after the zoologists returned to Príncipe, our botanists and mycologists, Tom, Rebecca, Dennis and Brian did a little more work on the big island before flying home. The photo below was taken by Dr. Brian Perry on one of their last days on the islands, and I just learned of this discovery. The first image is of pods on a cacao tree by the roadside near a place called Bombaim, in mountainous central São Tomé. The cacao pods are infested with a fungal pathogen known as frosty pod rot, Monilophthera roreri. Brian and Dennis have positively identified it.
Frosty Pod Rot near Bombaim, Sao Tome Island. B. Perry phot - GG III
Cacao (or cocoa, the source of chocolate) is native to Central America and was brought first to Príncipe in the 1820’s by the Portuguese. During the Portuguese era the cacao industry on the islands was the largest in the world; based largely on slave labor, the industry declined at the end of the slave trade, and new plantations were established in Ghana by Cadburys, the one of the main European buyers and producers of chocolate. While the industry is now much reduced, it is still important to the economy of the Republic of São Tomé and Príncipe.
Healthy cacao pods on Sao Tome. D. Lin Phot. GG II
Frosty pod rot has devastated the cocoa industry in Central America from Mexico to Panama for over 50 years causing up to 80% crop losses in some localities. What we do not know is whether the growers of São Tomé and Príncipe know of the presence of this pathogen on the islands yet; we have just sent this picture together with the precise locality data to our friends in the Ministry of the Environment to alert them. We are hoping the authorities are already aware of the threat and have taken steps to deal with it. The whole frosty pod rot story can be found here:
http://www.worldcocoafoundation.org/info-center/documents/Phillips_Frosty_Pod_COPALPresentation.pdf.
Alex Kim at Intel Awards - Media photo.
The good news is that Alex Kim, our high school colleague in Virginia who has been working on freshwater shrimp took 7th place at the 2009 Intel Science Talent Search. This is a remarkable achievement as the finalists included 40 of the most highly talented kids in the country. He is continuing his study of our São Tomé prawns and will keep us informed of his results; frankly I have a feeling we will be hearing a lot about this young man for years to come. Here is the url with descriptions of the projects, including Alex’s: http://sciserv.org/sts/68sts/winners.asp
Snakes are next in a return to “Slytherin”
The parting shot.
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 F. Breed, Gerry F. Ohrstrom, Timothy M. Muller, Mrs. W. H. V. Brooke and Mr. and Mrs. Michael Murkami for helping make these expeditions possible.
The Race: Return of the Marines Redux!
Category: Biodiversity, Gulf of Guinea, Island endemics, Sao Tome, Uncategorized, barnacles, biogeography, coral, invertebrates, principe | Date: Feb 20 2009 | By: islandbiodiversityrace
I have just heard that Alex Kim, the student at Thomas Jefferson High School of Science and Technology in Virginia has received the new freshwater prawns GG III (B) collected for him and is in the process of extracting DNA from the fresh tissues. As I mentioned in the last couple of blogs, Alex is a finalist in the Intel Science Talent Search, and we are very interested in his progress. His results will add to our understanding of our own work and the biodiversity of these islands. When Alex first contacted me, I had some concern that we might have neglected to bring prawns back with us from GG I and II. We had, of course, and Alex has been studying some of the preserved specimens er brought to him in December. Just yesterday I found an image of Dr. Tomio Iwamoto carefully processing these some of these same prawn specimens in 2006 on São Tomé (during GG II). This will give you an idea of the size of the critters Alex is studying (although there are two species on the islands – I am not sure which one this is!)
Tomio Iwamoto on Sao Tome. RCD phot. GG II
The marine biologists of GG III (B) are busily sorting through their material, and I thought an early update was in order. In the last blog I mentioned that the Dr. Williams had done very well with his octocorals (also known as gorgonians or sea fans), and so had Dr. Van Syoc and Dana Carrison with their barnacles. Dana is Bob Van Syoc’s graduate student at San Francisco State University.
Dana Carrison during a more northerly field trip. NOAA photo
Bob Van Syoc found an undescribed barnacle species on São Tomé during GG II, and it appears that Dana has now confirmed this for Príncipe as well. And there may well be other new barnacle species; it is just too soon to tell. Dana is studying the relationship between these barnacles and Dr. Williams’ sea fans. This is an obligate relationship – some species of sea fans are always found in association with certain species of barnacles.
The barnacle Conopea calceola on a gorgonian. D. Carrison phot. GG III
Note that the barnacle settles on the gorgonian, and the gorgonian’s tissue (red, in this case) grows up around it. Along with describing new species and adding to our island biodiversity list, Dana is testing the hypothesis that the different species of barnacles have a preference for certain species of gorgonian upon which to settle. Dana got about 30 different Príncipe barnacles but has not yet begun identifying them or comparing them to the GG II barnacles collected in São Tomé. Also included in her collections are at least three different gorgonians and their associated barnacles that were not collected previously by the Academy expeditions.
Undescribed species of Conopea on a different species of gorgonian. D. Carrison phot. GG III
New barnacle species or the relationships of freshwater prawns may not sound exciting to you. In our biodiversity race, we are studying everything we can, as biodiversity is the sum of all living species in a given area; thus, everything is important as a measure of the uniqueness and past history of these ancient islands. Think of our mushroom work: before we started, there were only four species known from São Tomé and none from Príncipe; now the people of the islands know that there are at least 220 species, many of them undescribed and unexpected. The same is true for the ant lions I have documented earlier, and I fully expect similar results when analysis of our collections of diatoms and spiders are completed. The story of biodiversity can never be told by the study of furred and feathers critters alone.
Here’s the parting shot:
Incipient Dr. Uyeda with collecting party, Nova Cuba, Principe. 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 F. Breed, Gerry F. Ohrstrom, Timothy M. Muller, Mrs. W. H. V. Brooke and Mr. and Mrs. Michael Murkami for helping make these expeditions possible.
The Race: Return of the Marines!
Category: Biodiversity, Sao Tome, Uncategorized, coral, fish, invertebrates, nudibrachs, principe | Date: Feb 10 2009 | By: islandbiodiversityrace
This is a brief update on the return of our people last weekend from Gulf of Guinea III (B). They were the marine component of the 2008-2009 expeditions (see Send in the Marines). The focus of four of the group was the waters of Príncipe, the much older of the two islands. The two fish people, Dr. John McCosker and David Catania went a week earlier to dive in São Tomé; neither had been to the islands before, and much of our earlier fish work was freshwater in nature. After the second group of four arrived, the whole expedition flew to Príncipe courtesy of SCD, one of our main sponsors (see “Partners,” below).
As I posted earlier, our first nudibranch (sea slugs) specialist, Dr. Marta Pola-Perez, was on the GG III (B) expedition. Below are photos of a few of the critters she found.
A possible new species of Phidiana, Principe. Pola-Perez phot. GG III
Flabelina arveloi, Principe. Pola-Perez phot. GG III
Hypselodoris bilineata, Principe. Pola-Perez phot. GG III
As I wrote before, Dr. Bob Van Syoc, his graduate student, Dana Carrison and Dr. Gary Williams are looking at corals and barnacles and the association between the two life forms. Dana’s dissertation topic concerns the relationship between what we think is a new species of barnacle and one of Gary’s octocorals (sea fans).
A Sao Tome sea fan (Eunicella). G. Williams phot. GG III
This group did quite well on Príncipe; Bob and Dana collected a barnacle species previously known only from the Azores and Cape Verde Islands, Megabalanus azoricus, thus adding to the island diversity list. Gary thinks he has now collected more species of octocorals in São Tomé and Príncipe than are found on the Galapagos Islands.
Grad student, Dana Carrison, with sea fan on Principe. B. Van Syoc phot. GG III
Dana, Gary Williams and John McCosker, Principe. B. Van Syoc phot. GG III
Of particular interest is that Bob found a species of shore barnacle at Bom Bom on Príncipe otherwise known only from South Africa. He thinks it was probably brought in by barge carrying building supplies. So far it seems to be confined to the vicinity of the Bom Bom pier.
Bom Bom pier at night, Principe. Weckerphoto GGIII
John and Dave also well. Although they said the diving was “spotty” they did manage to sample a bunch of neat stuff, including at least one definite new species.
A new species of Serranus from both islands. D. Catania phot. GG III
Ichthyologists frequently find new species just by exploring fish markets. Below is a pot of jacks for sale which John and Dave cannot identify to species. They will need to compare the DNA of these fishmarket critters with other known species in the genus.
Unidentified species of Caranx in the fishmarket. J. McCosker phot. GG III
As I have written before, another way for ichthyologists to sample the marine fauna is to get permission to buy odd specimens directly from beach seiners.
Sao Tome beach seine. J. McCosker phot. GG III]
This group was fishing in the bay near Omali Lodge (Marlin Beach Hotel), and like Dr. Iwamoto did during GG I, John and Dave dealt directly with the seiners for unique specimens. Detirmining the identity of all of this material takes a great deal of time, but for now it looks as though the Marines of GG III (B) did quite well.
I received some great news while the group was gone. Recall that I mentioned the marine group was going to collect some freshwater prawns for DNA work in a project by high school student Alex Kim in Virginia. Well, the group got the prawns and by now they are back east being investigated by Alex and his mentor from George Mason University, Prof. Patrick Gillevet. But the great news is that Alex is one of 40 finalists in the INTEL SCIENCE TALENT SEARCH; his project and scholarship are obviously gaining recognition, and we at the Academy are proud to be able to help out.
Alex has his own website: http://amphidrome.wordpress.com/
Here’s the parting shot:
Growing up on Principe. R. Wenk photo. 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 F. 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: Within the House of Slytherin (I. Lizards)
Category: Biodiversity, Gulf of Guinea, Island endemics, Sao Tome, biogeography, gigantism, invertebrates, lizards, principe | Date: Jan 26 2009 | By: islandbiodiversityrace
Our race to discover and describe the unique fauna and flora of São Tomé and Príncipe continues, and the six members of Gulf of Guinea Expedition III (B) are diving in the ancient waters of Príncipe as I write; they return to the Academy next week. As I wrote earlier, Marta is sampling the sea slug fauna (nudibranchs), Gary, Bob and Dana are looking at coral and barnacles, having found a new species of the latter in waters off São Tomé during GG II, and John and David are looking at small marine fish, with emphasis on eels. The group has an added goal, and that is to bring back some freshwater prawns (Macrobrachium) that abound in the São Tomé rivers. These specimens are for a young high school student named Alex Kim.
A freshwater Macrobrachium prawn from Guinea (www.)
Alex is a senior at Thomas Jefferson High School of Science and Technology in Virginia. He is doing an ambitious biogeography project on these prawns, relatives of which are found on both sides of the Atlantic. Alex contacted me through this blog—you can read his comments at the end the November posting. During a brief visit to DC over the holidays, I brought some preserved specimens we collected in GG I and GG II which I handed over to one of his advisors, Dr. Patrick Gillevet of George Mason University, and now the GG III (B) group plans to bring him some fresh material for DNA studies. This is really fun academic stuff, and we are delighted to have the involvement of a young colleague.
A Macrobrachium prawn from Cameroon. (www)
Except for documenting our exciting hunt for Príncipe Jita, (see first May posting), I have not written that much about the endemic reptiles of these islands; in fact, there are quite a few of them, some rather spectacular. While reptiles, especially geckos and skinks, are much better dispersers over saltwater than amphibians, snakes are not particularly good at it; moreover, like the amphibian caecilian, cobra bobo, a number of these endemics are legless species. There are also some island species that may be endemic, but we are not sure…. we just haven’t studied them closely enough yet. In this posting I will show you the unique lizard species. One readily identifiable endemic species is Greeff’s gecko, or the Giant gecko, Hemidactylus greeffii.
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Greeff’s Gecko, Hemidactylus greeffii . A Sao Tome specimen. RCD phot. GG I
Greeff’s gecko is an island giant; it is evidently much larger than other African member of the genus (and there are over 55 African taxa of Hemidactylus with likely many more to be discovered). Our longest specimen is over 200 mm in total length (including original tail); but longer specimens are known. This gecko is not only very large it also differs from all of its African relatives in lacking a claw on the first (inner) finger and first toe. Somehow, this feature has been lost during the thousands, perhaps millions of years of isolation on the Gulf of Guinea Islands. Greeff’s gecko also has greenish eyes, which also distinguishes it from other nocturnal geckos on the island which, so far as we know, are not endemics.
H. greeffii. Note absence of claw on first thumb. ST specimen. RCD phot. GGI
H. greeffii with greenish eyes. ST specimen. D. Lin phot. GG II.
Greeff’s gecko occurs on both São Tomé and Príncipe; at least we think it does. Here’s what I mean: specimens from both islands look very much the same but a couple of years ago, a group of researchers from the University of Madeira and Portugal looked at the DNA of specimens from both islands and found that data from mitochondrial DNA suggested the two populations were very different, and that they may well be two distinct species in spite of their apparent anatomical similarity. These results were not confirmed by study of nuclear DNA however, so scientifically the “jury” is still out, and we call both island forms, Greeff’s gecko. This critter is quite common in rock walls, culverts, rock crevices on both islands and is strictly nocturnal.
Principe specimen of Greeff’s gecko. D. Lin phot. GG II.
A similar situation exists with a small terrestrial skink called Panaspis africana, or Gulf Leaf-litter skink. A daytime forager, this small uniform-brown skink is very common in the lowlands; it can be easily heard and seen scuttling through dried cacao leaves and it is almost always found on the ground on both islands; one of our largest gravid (with eggs) female specimens from São Tomé is about 100 mm in total length, but most of our examples are smaller.
Gulf Leaf-litter skink. Panaspis africana; D. Lin phot. GG II.
The same group of researchers from the University of Madeira studied the DNA of leaf litter skinks of both islands, and also Annobón, the last island in the chain and part of Equatorial Guinea. They used, in part, tissues and specimens collected by us during GG I in 2001. In this case they found clear evidence for three separate species, one on each island (the one on Annobón is already called P. annobonensis); this was supported by both mitochondrial and nuclear DNA sequence. However, in one of those tragic, fortunately rare, occurrences in science, the specimens from which the tissue samples were taken were either lost in transit or misplaced. Without voucher samples the results cannot be duplicated or tested nor can we demonstrate the results. So for now, although there was evidence that Panaspis is two different species on São Tomé and Príncipe we cannot confidently describe the populations of the different islands nor give them scientific names. Until the study can be redone with new material, the Gulf leaf-litter skinks remain known as simply Panaspis africana.
Author working on Principe. Weckerphoto. GGIII
The way we collect these specimens is not sophisticated – we use our hands. We turn over logs, rocks and branches on the ground or sift through leaf litter with rakes; we climb trees and cliffs; we go out at night with flashlights and headlamps. After capture, the specimens are put in separate plastic bags for later processing.
Dr. Iwamoto in Sao Tome H. greeffii habitat on Sao Tome. RCD phot. GG I
Jens Vindum searching leaf litter on Sao Tome. D. Lin phot. GG II
Principe day gecko in plasic bag. RDC phot. GG III.
Every specimen we collect gets a unique field number, which is the same used for photographs of it, recordings or tissues samples taken.
My grad student, Ricka Stoelting, processing specimens on Principe. RCD phot. GG I
Certainly one of the oddest endemic lizards is the legless skink, unique to Príncipe Island, Feylinia polylepis. There are about six species known in this genus, the remaining five found broadly distributed on the African mainland.
Principe legless skink, Feylinia polylepis. brown phase. D. Lin phot. GG I.
They appear in two different color morphs, a brown one and a pale gray one, regardless of size or sex. The locals call them, Ozhgah (or at least the name sounds like that).
Principe legless skin - grey phase. D. Lin phot. GG II
Feylinia polylepis head shot. D. Lin phot. GG II
They can be found under almost anything on the ground provided the earth is slightly moist. Once exposed, they are very quick and can rapidly disappear into holes in the ground. They are conspicuously common in the Príncipe lowlands, and in this regard are reminiscent of the caecilians of São Tomé Island; the high density of their numbers in suitable habitats suggests predation may be low in these areas.
Not all geckos are nocturnal. In the Old World there are two large groups that are secondarily diurnal, although they, like all geckos, lack eyelids. The genus Phelsuma is a group of numerous species of velvety green geckos found on Madagascar and the Indian Ocean islands; the other group, Lygodactylus are also present in Madagascar but also distributed throughout the Afrotropical region as well. They are not brightly colored, and taxonomically rather poorly known. The group as a whole is being studied by Dr. David Vieites (and his students) of Madrid and Dr. Adam Leache, of the University of Washington. I have been involved as well but largely in studying the relationships of day geckos of the Gulf of Guinea Islands.
Lygodactylus thomensis. Sao Tome. D. Lin phot. GGI
The Gulf of Guinea Day geckos are sun-lovers and strictly climbers, being fairly common on tree trunks and scuttling up walls even in São Tomé town and Santo Antonio, Príncipe. They are very small, at about 70-80 mm total length. The day geckos of the Gulf of Guinea islands (excluding the continental island of Bioko) have long been recognized as a distinct, endemic species, Lygodactylus thomensis, first discovered on São Tomé Island. The day geckos on Príncipe and Annobón have been described as subspecies (or races, if you will) of the São Tomé species.. As you can see from the illustration below, one of the characteristics used to define species of day geckos is the throat pattern.
Day geckos of the Gulf of Guinea Islands. RCD prep.
The throat patterns of the lizards on each of the three islands are quite consistently distinct from one another, and work by us and the University of Madeira suggest that they have been isolated from each other for a long, long time, and that each is a full species unique to its island. Work is continuing on these lizards.
L. delicatus of Príncipe Island. RCD phot. GG III
There are other conspicuous lizards on both islands but these are not considered endemics; i.e., they occur elsewhere and are probably just good over-water dispersers. The large speckled-lipped skink, Mabuya maculilabris, is common and widespread in the lowlands of both São Tomé and Príncipe. It is a good climber and is seen in a variety of habitats especially along the coast lines. This species also broadly distributed on the African mainland.
Speckle-lipped skink (Mabuya maculilabris) of the Gulf of Guinea. Sao Tome. D. Lin phot. GG II]
M. maculilabris detail. D. Lin phot. GGII
There are also non-endemic, nocturnal geckos on both islands. Most appear to be the widespread house gecko, Hemidactylus mabouia, also occuring nearly throughout Africa.
House gecko, Hemidactylus mabouia. D. Lin. phot. GG II\]
Note that the eyes are not greenish and that this species does not lack claws on the inner toe and finger. There is some confusion as to how many non-endemic species are present and what to call them.
H. mabouia foot from beneath. note claws. Weckerphoto GG III.
Snakes are coming next.
Here’s the parting shot:
The thrill of discovery! Bom Bom Island, Principe. 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, Victor Bomfim, Salvador Sousa Pontes and Danilo Bardero of the Ministry of Environment, Republic of Sao Tome and Principe 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 F. Breed, Gerry F. Ohrstrom, Timothy M. Muller, Mrs. W. H. V. Brooke and Mr. and Mrs. Michael Murkami for helping make these expeditions possible.
The Race: A Toad Less Traveled
Category: Biodiversity, Gulf of Guinea, Island endemics, Sao Tome, frogs, gigantism, principe | Date: Dec 15 2008 | By: islandbiodiversityrace
Sorry, I love titles like this… and I have more! Actually, there are no toads (Bufonidae) on São Tomé and Príncipe; interesting in itself because seven other amphibian species of five different families have survived the ocean crossing during the many millions of years since the islands first emerged. Moreover, toads are common in almost every conceivable terrestrial mainland habitat.
My last two blogs have been a bit academic. Having laid the biogeographical ground work, it is probably time to get back to the unique, endemic island critters. The tiny, 31-million year old island of Príncipe is the only home of Africa’s largest treefrog, Leptopelis palmatus – the Príncipe Giant Treefrog. It is one of the world’s rarest frogs, as well.
L. palmatus – D. Lin phot. GG I
Let me be quick to point out that the Príncipe critter is not Africa’s largest frog; that title belongs to Conraua goliath (below), which is found on the mainland in southern Cameroon and Gabon. In fact, the goliath frog is the largest in the world but it is not related to any on São Tomé and Príncipe– no members of its family have made it across the saltwater gap to the islands, or if they ever did, they have not survived.
Conraua goliath—J.-L. Perret phot.
Leptopelis palmatus is the largest African treefrog (emphasis on “tree”) — frogs that are adapted for climbing with, among other features, enlarged finger and toepads. As I have pointed out in earlier blogs, gigantism is a relative thing; the giant endemic plants, frogs, birds and lizards of São Tomé and Príncipe are bigger than all of their relatives but they are not necessarily so large you trip over them (like Galapagos or Aldabra tortoises); they are simply larger than all of their relatives. The two images below put this frog in some perspective, and I think you will agree that this is one BIG treefrog.
Me, with the first female. R. Stoelting phot. GG I
The frog on Dong Lin, our photographer. R. Stoelting phot GG I
This species was first described in 1868 on the basis of a single female specimen, housed in the Berlin Museum. At the time of GG I in 2001, the Príncipe giant treefrog was known only from this single type specimen and seven additional specimens, all females, collected by local Príncipeans for a Swiss colleague named Catherine Loumont. The largest of Loumont’s specimens is 110 mm from snout to vent (we do not include legs when we measure frog sizes), and even after our years of work, this specimen remains the largest ever found – it is nearly 30 mm longer than the largest of its nearest mainland relative, Leptopelis macrotis, distributed from central Sierra Leone to Ghana. One of several differences between the two species is the striking deep-red eyes of our island endemic.
The eye of the Príncipe giant treefrog. D. Lin phot. GG II
This first specimen we found during GG I (first three treefrog images, above) was yet another female, 108 mm in length. Our mammalogist, Doug Long, was led to the critter by some kids from the now-defunct plantation of Sundi in northwest Príncipe. Sundi may no longer function as a plantation but it is still inhabited by the descendents of former workers—lots of them, there is even a mayor.
Doug Long and the Sundi kids. RCD phot. GG I
The arrival of this frog was greeted with great enthusiasm by yours truly; here in my hands one of the rarest frogs in the world! And it was huge! I was not surprised to learn that it had been found on the ground, as it is hard to imagine something so bulky climbing around in bushes and trees. The male of this species was completely unknown, so far as we knew at the time,. None had ever been collected, photographed nor described in the scientific literature. So we also knew nothing about the species’ breeding biology, male advertisement call or tadpole. At the time, we were unaware of a blog posted two years before our visit by Jonathan Bailey on the Gulf of Guinea Conservation Group website, entitled “One month in the Forest of Príncipe.” Jonathan (now Dr.) Baillie described hearing the calls of male L. palmatus as “like a pop bottle being continuously opened.” He heard them high up on Pico do Príncipe near a small stream at about 700 m and actually collected two of them which had been deposited in the Natural History Museum in London. But during GG I, the male giant treefrog was terra incognita, so far as we were concerned.
Second female from Rio Papagaio. J. Ledford phot.. GG I
During a second GG I visit to Príncipe a few weeks later, my then-graduate student, Ricka Stoelting, collected another female along the Rio Papagaio, a large-ish river that flows through Príncipe’s only town, Santo Antonio. It was also of a rather dull in color but with white spots. We have since learned that this is about as brightly colored as females get.
Rio Papagaio in town, downstream. RCD phot. GG III
Ricka Stoelting, my graduate student on Sao Tome. RCD phot. GG I.
During this second visit, Ricka and Dr. Sarah Spaulding ascended Pico do Príncipe to the top and camped at nearly the same spot where Jonathan Baillie had been two years before. There she found the males, lots of them, calling from bushes and branches at night near a very small creek.
Tiny creek on the Pico. J. Uyeda phot. GG II
Ricka brought the series of males back down the mountain, and they were astounding. Unlike the females they were very brightly colored and highly variable, in pattern, as well; this variability is rather unusual in frogs, although there are some species that are sexually dimorphic for color. And they were much, much smaller than the females, though we knew they were full-sized breeding adults. During later analysis we learned that the largest breeding males are only about 41% of the size of the largest females, a size disparity that is striking.
First series of live males (far right is a juvenile). J. Ledford phot. GG I
Ricka never heard them calling and anyway she had no way of recording them if they had. One of the parameters we use in establishing relationships among frog species is analysis of the voice (or advertisement call.). Males call to attract females, and at the same time to advertise their presence and territory to other males. The advertisement call is species- specific and obviously adaptive when there are other species utilizing the same water for breeding. To really define Leptopelis palmatus, I needed a recording of the voice, and this was to become a priority in the future. Below is a preliminary analysis of the call of another Gulf of Guinea frog species which we think is present on both islands. Here, we are comparing the advertisement calls of males from two different localities on both islands, and we can see that they are basically the same.
Preliminary sonograms of Oceanic treefrog. Marshall/Drewes construct.
Back at the Academy, Ricka and I prepared the first formal description of male Príncipe giant treefrogs. Now aware of Baillie’s blog, we read his word description of the advertisement call. Although the Principeans insisted the frogs did call, it remained an open question, especially when I learned from anatomical study that the male frogs lack vocal sacs and vocal sac openings, features that most calling frogs possess (including other members of the genus Leptopelis). GG II in 2006 included Josef Uyeda as my student (now a PhD candidate at Oregon State University). Josef was working on a different group of island endemics called puddlefrogs (see earlier blog: “We Find Jita”) but when we were on Príncipe, I sent him up the Pico with his friend Mac and the same guide, Manona, who had led Jonathan Baillie and Ricka years before. They were armed with my old Sony cassette recorder (my iPod had failed). Bear in mind that the only known localities for males were at nearly 700 m, high on the Pico and while this made no biological sense, that’s where my stalwarts had to go. This is no small matter given the topography of the island, but graduate students are good at this sort of thing and anyway, they tend to be younger and more vigorous than their advisors!
Principe terrain. Pico do Príncipe is in the clouds to the left of the large Pico Papagaio. R. Wenk phot. GG III
Josef Uyeda hunting for caecilians on São Tomé. D. Lin phot. GG II
While in the same general area as earlier workers at about 700 m, Josef got a lot done but the party was caught in heavy rains. He heard males and saw them calling but only managed some rather distant, poor-quality recordings (the conditions were miserable), but now at least we knew that the frogs did, indeed, call. GG III, last spring, provided some answers, thanks in part to our friend Ramos of Bom Bom Island. Ramos is assistant manager of the resort, a native Principean and a keen, observant naturalist. See the photo of Ramos in the “We Find Jita” blog. I described our past difficulties in trying to record the voice of the Príncipe giant treefrog to him, and he grinned and said, We will go to my roça (farm) on Pico Papagaio and at 5:30, we will get them! I was highly skeptical…
Roça Papagaio, Ramos’s farm at 250 m. R. Wenk phot. GG III
Ramos’s farm is in the forested area on the northern flanks of Pico Papagaio at about 250 m. Just before you reach it on a dirt steep uphill road, you cross a tiny creek; this is where Ramos took us – about 30 m up that small creek, thick with dense undergrowth, and there we sat, waiting for the forest cacophony of grey parrots, mona monkeys to subside. Nothing much happened. I had my iPod with recording head at the ready. We waited in the gathering gloom for about 20, maybe 30 minutes, Ramos grinning throughout and occasionally exclaiming, Just wait. We will get them!
Me waiting, iPod in hand, for the giants to call. T. Daniel phot GG III
And sure enough, we began to hear frogs calling. I looked at my watch. It was 5:30. The call is certainly a strange one; it lacks resonance (remember males don’t have a vocal sac) and thus it is rather flat and unmelodius. Rather than my trying to describe it or arguing with earlier descriptions, you can listen to it yourself by clicking this link:
And here are a couple of photos of the male that was calling, taken by Wes. These are un-posed and taken before we collected it as a voucher specimen for the voice:
Weckerphoto GG III
Weckerphoto - GG III
There are still great gaps in our knowledge of this most unique frog. Obviously, the males are well-distributed in the lower elevations; we just have not been in right place at the right time. We still cannot explain why females are dull and rather cryptic in coloration and usually found on the ground, while there appears to be no selection for color in males. The dull color of females seems consistent, as a couple of months ago I found six additional females (no males) collected in 1988 at the Doñana Institute in Seville and they were clearly drab in life; my colleagues at Donana tell me they were collected on the ground in lowland localities at Rio Papagaio and Bela Vista.
Six female Seville specimens at Donana Institute. RCD phot.
We still have not observed breeding, nor have we ever seen tadpoles. In this genus, Leptopelis, they are very distinctive, and I would predict the tadpole will look like this:
A Leptopelis tadpole. Image courtesy of Dr. R. Altig
Here’s the parting shot:
Nezo, of Angolares, Sao Tome: artist, musician, restaurateur and worthy man - Weckerphoto GG III
PARTNERS We gratefully acknowledge the support of the G. Lindsay Field Research Fund, Academy 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 Sao Tome and Principe 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 four private individuals, George F. Breed, Gerry F. Ohrstrom, Timothy M. Muller and Mrs. W. H. V. Brooke for making these expeditions possible.
The Race: Strange Bedfellows (Part II)
Category: Biodiversity, Gulf of Guinea, Island endemics, Sao Tome, biogeography, gigantism, principe | Date: Nov 18 2008 | By: islandbiodiversityrace
First, I thought it would be useful to illustrate, in one place, how many scientists have been involved in the Gulf of Guinea expeditions since 2001 including the folks going in January 2009 (Gulf of Guinea III B).
In Part I of this blog, I suggested that it is not just the high numbers of plants and animals that are endemic to these islands that is striking; it is also the fact that many of them are particularly poor dispersers over salt water and, according to dogma, they just shouldn’t be there! A scientist would never predict the presence critters like amphibians on oceanic islands. Don’t believe me? Even Darwin himself made the observation:
Courtesy Dr. M. Vences, University of Braunschweig.
Amphibians and burrowing reptiles are among the most obvious of the unlikely inhabitants on the two islands but there are more subtle oddities as well. The plant group Acanthaceae (shrimp plants), which are the specialty of Dr. Tom Daniel (GG III – see May 2, “News From the Flower People”) is another group whose presence is surprising.
Dr. Tom Daniel. Lagoa Amelia, Sao Tome (RCD phot. GGIII)
Heteradelphia paulowilhelmina– an endemic genus? Weckerphoto GGIII
The seeds of this group have no “wings” or other morphological adaptations allowing them to be blown by winds (wind dispersal is very common among plants – think of dandelions). They do not float, they are too heavy, and anyway they are not salt-tolerant. If that were not enough, shrimp plant seeds do not have endosperm; i.e. they are not nutritious and thus are very unlikely to be routinely eaten by birds or mammals, then transported as stomach contents. In fact, seed dispersal in this group is accomplished by the capsule that bears the seeds “exploding” and casting the seeds a matter of a few meters away from the parent plant. Yet, there are 15 species native to the islands (non-introduced), two of which are endemic. How did they get there across the water?
I think the most likely answer to this question is that in the distant past these species crossed the marine barrier between Africa (the source) and the islands by floating on rafts. My colleagues and I published this “rafting hypothesis” about a year and a half ago, largely based on the study of one group of frogs; however, the more I learn about the island endemic fauna, the more I am convinced that this is the most likely scenario.
The first thing to remember is that two of the mightiest rivers on earth feed directly into the Gulf of Guinea - the Congo and the Niger. The Congo especially has an enormous drainage from deep within the African interior, and we know that the Niger flowed from current Lake Chad not so long ago; these might be considered amphibian freshwater highways from the interior to the coast. It is not difficult to envision rafts of matted vegetation, tree trunks etc., floating downstream on one of these great rivers and being discharged into the Gulf of Guinea. But we propose rafts composed of huge chunks of riverbank, chunks large and diverse enough to harbor burrowing forms and amphibians.
Illustration by Richard E. Cook, San Francisco.
Such rafts might be many acres (hectares) in size such as in this drawing by my artist friend, Richard Cook. Rafts of this size might be expected to have rotten logs, trees, bushes rocks etc. Does this actually happen? Yes, such huge rafts containing all manner of wildlife are fairly common breaking off and floating down the Amazon and the La Plata (they are called Camalotes); however, in the case of the Amazon, they are not often discharged into the Atlantic. Rather, they tend to accrete together at the delta, forming large masses.
Satellite image, from World Wide Web.
In the satellite image above, the red star indicates a large accretion island in the Amazon Delta called Marajó – it is about the size of Belgium! I can think of two possible explanations for why islands formed in the Amazon accumulate at the delta rather than float out to sea.
RCD phot.
First, notice above that the water remains relatively shallow for a great distance seaward from the Amazon Delta; this is because the continental shelf is about 200 miles wide before dropping off into great depths. By contrast, the continental shelf off the Niger and Congo Rivers is much narrower (arrows on the right); moreover, just offshore from the Congo Delta is a deep abyss called the Congo Canyon. Second, I think the water velocity in the Amazon is significantly lower in the Amazon than it is in the Congo, at least. In fact the Congo is only navigable for about 80 miles inland. The yellow star in the image below is the town of Matadi, which is as far inland as one can get by boat.
Matadi, D.R.C., as far as you can go. (RCD phot. 1984
Upstream from Matadi are a series of rapids or cataracts formed as the river cuts though the African coastal uplift.
Congo cataract. Google Earth image.
Rapids below Stanley Pool, D.R.C. - Souljah phot. WWW.
These rapids increase the water velocity so that I suspect the river is much swifter overall than the Amazon, and it is far more likely that floating objects would be ejected out over deep water from the mouth. How such floating objects would survive the cataracts themselves is an open question. Given a large chunk of riverbank being ejected out into the Atlantic Ocean from the mouth of the Congo, what happens next?
Google Earth, RCD composite.
The image above shows the mouths of the Congo and Niger (yellow stars) and the directions of the dominant ocean currents in the region. Note that any floating object ejected from the Congo River will immediately encounter the Benquela Current and be carried north; such an object from the mouth of the Niger will be carried East by the Guinea Current. It so happens that these two major currents converge to form the South Equatorial Current which flows due west, right through the central Gulf of Guinea Islands! Conditions being perfect, we estimate that a floating object would take less than two weeks to reach São Tomé or Príncipe from the mouth of the Congo. But, given our knowledge of the physiology of amphibians, what about the effects of the saltwater during the voyage. Well, it seems that at predictable times of the year, the surface water of the Gulf of Guinea is not all that salty.
From Measey, et. al. (2007). Journal of Biogeography
Notice that during the rainy season (around February) the surface salinity around the islands drops to around 31 parts per thousand of salt (technically it is brackish). Recall that because of differences in density, freshwater floats upon salt water. This sharp decrease in surface salinity is due to massive freshwater discharges of both the Congo and the Niger into the Gulf, plus the extremely high precipitation in the area as a whole. And of course, with high flow rates and the two mighty rivers in spate, this would be the time of year when pieces of riverbank would be most likely to break off and flow downstream. So a combination of factors, the locations of the rivers, the directions of the dominant ocean currents and periodic surface salinity changes, all point to rafting as the most likely way the amphibian ancestors of the current endemics actually arrived on the islands. We cannot prove this happened; we simply claim it is possible and likely. Moreover, , one must bear in mind that there has been a 13 million year period during which it might have in the case of São Tomé; as for Principe, it has been sitting out there “available for colonization for over 30 million years!
Here is the parting shot:
Angle of Repose on Principe. Weckerphoto, GG III.
PARTNERS We gratefully acknowledge the support of the G. Lindsay Field Research Fund, Academy 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 Sao Tome and Principe 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 four private individuals, George F. Breed, Gerry F. Ohrstrom, Timothy M. Muller and Mrs. W. H. V. Brooke for making these expeditions possible.
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I am Dr. Robert (Bob) Drewes. I am Curator of Herpetology at the California Academy of Sciences and specialize on the evolutionary biology and natural history of African reptiles and amphibians. During my entire career, spanning over three decades, I have conducted virtually all of my field work in Africa. Since 2001, I have been leading multidisciplinary research expeditions to the Gulf of Guinea, and our progress and activities are described in this blog.
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Island Biodiversity Race- The Race: New Species or What’s in a Name?
- The Race: New Fish Excitement
- The Race: Taming of the Shrew (and updates)
- Within the House of Slytherin (II. some snakes)
- The Race: Bad News/Good News
- The Race: Return of the Marines Redux!
- The Race: Return of the Marines!
- The Race: Within the House of Slytherin (I. Lizards)
- The Race: A Toad Less Traveled
- The Race: Strange Bedfellows (Part II)