California Academy of Sciences

Dispatch Number Two - April 17, 2001
Text by Bob Drewes, Herpetology

São Tomé was once known as "the island in the middle of the world," and in a way it really was. The Portuguese first landed here in 1470, back when most folks thought the world was flat. If you think about it, the Equator runs right across the little island off the south coast, and the Prime Meridian is only a few degrees to our west. Certainly, São Tomé was in the middle of the world as it was known at the time of Portuguese exploration.
pit traps
We help Charles put in his pit traps at 1300 meters on the mountain Bom Successo. Photo Robert C. Drewes
Hemiadactylus greefi
One of our guesting beasts, the endemic São Tomé gecko, Hemidactylus greefi, from the tunnels in the Contador Valley.
Photo Robert C. Drewes
Bom Successo
Ricka explores leaf litter in buttress roots near Bom Successo.
Photo Robert C. Drewes
Charles arrived on the 6th, via Air Gabon after a pretty miserable time in Libreville. Fortified with a beer or two and a tour down the eastern side of the island, he headed straight for the mountains. We set up his pit traps at about 1300 meters, near the island´s tallest radio antenna. They have been quite successful, and in fact the montane arthropod fauna is very diverse, even including the tiny commensal spiders that cannot live without their host spider species. It is here that we have found our first and only sample of the endemic treefrog so far, Nesionixalus thomensis,. We found. a group of adults in a pool in a hollow tree along with eggs and tadpoles. The other species, which Bob believes is Hyperolius (not Nesionixalus) molleri, is much more common and found lower, nearly to sea level.
Lagoa Amelia
Jens and Bob triangulating by the calls of the elusive Lagoa Amelia treefrogs.
Photo Dong Lin
Lagoa Amelia
Tino assists Dong over the gauntlet of yucky mud forming the periphery of Lagoa Amelia, above 1400 meters.
Photo Robert C. Drewes.
Hysterocrates gigas
"Bubba" (Hysterocrates gigas), one of the largest spiders in Africa. Jens captured Bubba beneath a large log near Lagoa Amelia.
Photo Robert C. Drewes

Fabio, Dong and Doug arrived on the 10th. We have spent considerable time at Lagoa Amelia, a swampy lake in the central massif at 1400 meters. All along we have been informed there are no frogs above 500 meters... but this is not so. We have collected two endemic species in Lagoa Amelia, the tiny brown Phrynobatrachus dispar, and Hyperolius molleri, our highest amphibians so far.. Up at Lagoa Amelia, Jens found "Bubba," an enormous, heavy tarantula, under rotten log.. Charles was most pleased. We also learned later that these critters get a lot bigger than Bubba. Our eyes are peeled.

Sao Tome aqueduct tunnels
Charles emerges from one of the aqueduct tunnels in the Contador Valley at 600 meteres.
Photo Robert C. Drewes
One of our most interesting sites is on the western slope of the Contador Valley, perhaps São Tomé´s deepest. There is much original vegetation, and in the 1950´s, the Portuguese built an aqueduct that runs along the 600 meter contour line through a number of tunnels. One of the tunnels is over 350 meters long. These tunnels are loaded with all sorts of neat creatures like bats, whip scorpions (big ones!), and the endemic gecko, Hemidactylus greefi. We miss not having a botanist with us as there are all sorts of flowering plants around, many of which we are informed are endemic.
Contador Valley
One of many flowering plants at 600 meters in the Contador Valley.
Photo Robert C. Drewes

The basalt cliffs on the northwest side of the island near Laguna Azul have also been productive. We were informed early that there are no scorpions on the island, but saw two our first night at the cliffs, and later Charles collected one of the genus Buthus. At night the lower elevations are alive with land crabs, giant snails, lots and lots of night critters. We have twice seen the cat-like Palm civet, supposedly introduced here years ago. One of Douglas Long´s bat colonies is located in a culvert at this locality.

Douglas handles his first bent-winged bat, Miniopterus, from the Contador Valley. Photo Dong Lin.
An impressive whip scorpion (Amblypigida .. not our largest!) from the tunnels in the Contador Valley.
Photo Robert C. Drewes
land crab
Jens and "Billy," an enormous land crab; night time at the basalt cliffs near Laguna Azul.
Photo Robert C. Drewes

Tomio and Quintino or Allen continue to seine rivers at various altitudes. Although he is not sure what he actually has, he´s sure he has more different species than have been recorded in the past. Bob and Tomio also watched a group of fishermen hauling in a long net from the shoreline, then went through the catch and purchased a number of species that Tomio thinks have not been recorded as part of the marine fauna.

Agua San Pedro
One of Tomio's river catches - a goby of the genus Sicydium from Agua San Pedro.
Photo Robert C. Drewes
Tomio and Tino seine the Aqua San Pedro on the east coast. Photo Dong Lin

Our apartments continue to serve us well as both living quarters and labs. Now that Fabio and Dong are here and the laptop is finally functional, we will be able to keep more up to date. Norm arrived on the TAP flight yesterday morning, and it was with great sadness and regret that we said farewell to Jens who left for home on the same plane. He will be missed by all of us.

Tomorrow we are off by small boat for the island of Principe... We will be out of touch for 6 days, but will prepare a third dispatch as soon after our arrival as we can.
Back at home base the gang photographs a treefrog from the central mountains.
Photo Robert C. Drewes





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