2016 Expedition to the Upper Ireng River, Guyana
Draining remote Guiana Shield highlands at the border between Brazil and Guiana, headwaters of the Ireng River have always fascinated me. Headwaters of several nearby rivers host evolutionary curiosities among their fishes, some of which I have discovered during previous expeditions. Headwaters of the Ireng River, though, have never previously been sampled by ichthyologists. Tributaries of the middle Ireng River provided type material for several fish species described in the early 20th century, but headwaters of the Ireng River had never been surveyed before. Joining this first expedition to the upper Ireng were ichthyologists Jon Armbruster and David Werneke, herpetologist Tim Colston, ornithologist Kristof Zyskowski, University of Guyana students Mahendra Doraisami and Mark Ram, and artist David Brooks. Our expedition started on January 2nd, when we flew from Georgetown to Orinduik Falls – a collection of large cascades at Guyana's border with Brazil. We spent four days sampling fishes, herps and birds near Orinduik Falls then headed upriver to survey habitats near the Patamona community of Kaibarupai for six days. The expedition produced 30 species (174 lots) of fish, 27 species of frogs, 20 species of reptiles, and 215 species of birds. Particularly valuable fish collections included topotypes of Lithoxus bovallii (Regan 1906), Characidium crandellii Steindachner 1915 and Parodon bifasciatus Eigenmann 1912, and future type material for new species of Characidium, Harttia, Neblinichthys and Rivulus (see photos below). All fish specimens were cataloged at the Auburn University Fish Collection in Auburn, AL, and can be searched here (field number prefix: GUY16). All frog and reptile specimens went to the Sam Noble Museum of Natural History in Norman, OK, and can be searched here, and all bird specimens went to Yale's Peabody Museum of Natural History, and can be searched here. A collection of drone videos from this expedition can be viewed on my YouTube channel here.
1. Team members (L-R) David Brooks, Kristof Zyskowski, Tim Colston, Jonathan Armbruster, David Werneke, and myself gather for our first meal together as a team and our last meal in Georgetown before flying in to Orinduik. 2. On our flight to Orinduik, we passed over Kaieteur Falls. 3. Looking down the Potaro River valley downstream of Kaieteur. 4. An aerial view of Orinduik Falls, with Brazil on the left and Guyana on the right. 5. Our team is dropped off at Orinduik's dirt airstrip. 6. In the absence of a wheelbarrow or any other wheeled transportation at Orinduik, all of our gear and supplies had to be carried by hand. 7. Kristof opens a mist net near Orinduik Falls. 8. Admiring a Hypostomus hemiurus. 9. More fuel and gear arrives from Georgetown. 10. Tim photographs a bumble-bee poison dart frog (Dendrobates leucomelas) on a bromeliad near the base of Orinduik Falls. 11. Two specimens that were collected as a record of the biodiversity of the area. 12. Tim processes frog and reptile specimens, taking measurements and tissue samples from each. 13. My sleeping quarters, with an excellent view of Orinduik Falls. 14. Looking for fish in mud and leaf litter. 15. A ladder-tailed nightjar (Hydropsalis climacocerca) that was brought to us by one of our guides. 16. Heading up the Ireng River from Orinduik to Kaibarupai. 17. A long portage around rapids en route to Kaibarupai. 18. Our pile of gear upon arrival at our Kaibarupai camp, which was still under construction. 19. Our first glimpse of Andu Falls, on Sukwabi Creek, a tributary of the upper Ireng River. 20. Kristof shows David some of the distinctive wing features of a male Guianan cock-of-the-rock (Rupicola rupicola). 21. Kristof and Mahendra process bird specimens. 22. A white bellbird (Procnias albus) brought to us by a local boy. 23. Two assistants from Kaibarupai, Bennie (L) and Walter (R), with their catch of birds for the day. 24. Tim measures the head of a bushmaster (Lachesis muta). 25. Photographing a large undescribed crenuchid (Characidium n.sp.). 26. Collecting fish from a hiari station. 27. With a new species of Neblinichthys in the photo tank. 28. Group photo at the top of a large waterfall on the upper Ireng main channel. 29. Tim photographs a racer. 30. Kristof delivers an ornithological lesson to Brooks and Tim. 31. A pet agouti (Dasyprocta sp.) being kept by a girl from the village. 32. Our camp prepares for departure. 33. Meeting the plane back at Orinduik.
This fieldwork was funded by the Coypu Foundation.
1. Astyanax sp. 2. Bryconops affinis, 3. Moenkhausia browni, 4. Characidium crandellii, 5. Characidium n.sp., 6. Characidium n.sp., 7. Pyrrhulina stoli (male), 8. Erythrinus erythrinus, 9. Crenicichla alta, 10. Krobia potaroensis, 11. Rivulus n.sp., 12. Gymnotus carapo, 13. Neblinichthys n.sp., 14. Lithoxus bovallii, 15. Harttia n.sp., 16. & 17. Trichomycterus sp. Scale bar for all photos = 1 cm.