Biodiversity of the Rewa Head B Zoological Society of London ...

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Chapter 1. Mammalian Species Diversity and Relative Abundance The study of mammalian diversity and relative abundance was principally based on a line of camera traps erected in the 25 miles of river immediately upstream of Corona Falls. The species list presented in the appendix is a combination of observations recorded through camera trapping, sightings made while on drift transects and opportunistically as well as indirect evidence such as scats, footprints and burrows. Our reference was Emmons and Feer (1997) Neotropical Rainforest Mammals however we have used the most recent taxonomic revisions including the Guianan red howler monkey, (Alouatta macconnelli) and red-backed bearded saki (Chiropotes chiropotes). Principal Findings • 33 species of mammal recorded including all 8 of Guyana’s primates and 5 species of felid. • Healthy population of endangered giant otter ( Pteronura brasiliensis) with 5 groups recorded above the falls, equating to one group every 12 miles. Four groups were recorded below the falls. • 17 species of medium to large mammal recorded in camera traps including puma (Puma concolor), giant anteater (Myrmecophaga tridactyla) and margay (Leopardus wiedii). • Indirect evidence for the presence of bush dog ( Speothos venaticus) and giant armadillo (Priodontes maximus). • High abundance of Brazilian tapir ( Tapirus terrestris) with 5 encountered on the river and approximately 2.5 tapir roads crossing the river every mile. The animals encountered appeared naïve, due to the absence of hunting. Flagship species: The Giant Otter The highly charismatic giant otter (Pteronura brasiliensis) was the main focus of the expedition, as we were there to collect faecal samples for genetic analysis. The giant otter population is in the process of recovering from a hunting-mediated population crash in the last century which drove the species down to an estimated 3000 individuals range-wide (Carter & Rosas 1997). While no official estimate of pre-hunting population size exists, judging by skin export figures (Carlos et al 1985, Schenck 1996), it could easily have been as high as 50,000. Since placing the giant otter in CITES Appendix 1, the removal of an international market in giant otter skins has seen numbers rise. However, it remains under threat particularly through habitat degradation, mercury poisoning, and direct conflict with fishermen (Harris et al 2005, Groenendijk et al 2005). Throughout the population crash the Guianan Shield remained a stronghold for the species, a low human population density coupled with an interior which had yet to be opened up led to the giant otter surviving in this region while in other parts of South America it suffered local extirpation. The work of Diane McTurk and Karanambu Ranch fomented the impression of this charismatic predator in the public’s eye, creating an irrevocable association between Guyana and the giant otter that has since been strengthened by recent BBC documentaries in the region. Southern Guyana remains one of the top sites in South America to see giant otters and as such the species acts as a huge draw to many of the eco-tourists that venture to the Rupununi ensuring that there is also an economical interest in the survival of the species. Rob Pickles’ PhD is an investigation into the phylogeography of the giant otter, using mitochondrial DNA to analyse patterns of relatedness between populations determining whether there has been any divergence according to drainage basin, or whether palaeoclimatic events may have been responsible. It also investigates the degree of gene flow between populations which has important implications for effective management of the species. Biodiversity of the Rewa Head 11
Figure 9a. Territorial display by a group of giant otters above Corona Falls. Termed ‘periscoping’ the behaviour is accompanied by a cacophony of wails and snorts often backed up by a mock charge. For the biologist, periscoping allows pictures to be taken of the unique throat patterns allowing identification of individuals. Figure 9b. Inquisitive adult male giant otter approaching the boat. While some individuals are remarkably fearless and will approach to within several yards of the boat, the mood of the group is determined by the breeding female. If she feels threatened the group will normally periscope and disappear. 12 Biodiversity of the Rewa Head
Page 1 and 2: Zoological Society of London, Regen
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Page 8 and 9: Co n t e n t s Executive Summary 3
Page 10 and 11: ex e C u t i v e su m m a r y The r
Page 12 and 13: te a m Rob Pickles. BSc Zoology Rob
Page 14 and 15: Unlike its larger neighbour to the
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Page 22 and 23: Table 1. Species diversity and rela
Page 24 and 25: The data reveal a typical situation
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Page 28 and 29: Figure 24. A White-plumed Antbird (
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Page 34 and 35: ecorded claim boards over 20 river
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Page 38 and 39: Chapter 5. Conservation value of th
Page 40 and 41: Figure 39. A relict leviathan, the
Page 42 and 43: Groenendijk J, Hajek F, Duplaix N,
Page 44 and 45: ap p e n d i x i Mammalian Diversit
Page 46 and 47: ap p e n d i x ii Avian Diversity a
Page 48 and 49: Scarlet Macaw Ara macao F U S Golde
Page 50 and 51: Amazonian Barred Woodcreeper Dendro
Page 52 and 53: Capuchinbird Perissocephalus tricol
Page 54 and 55: ap p e n d i x iii Reptilian Divers
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