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Investigations into the properties of mistletoe leaves, Phoradendron spp. (Viscaceae) and geophagic material consumed by Ateles geoffroyi (Atelidae) at sites within the Santa Rosa National Park, Costa Rica

This project arose because of the desire by the resident Ateles research observers, at Santa Rosa, to attempt to ascertain a function for what they deemed ‘uncharacteristic’ behaviours. The following were important considerations meriting further investigation. • Phoradendron (mistletoe) consumption by Ateles spp. appeared to be present only at Santa Rosa; • Mistletoe selection was considered deliberate, as mature host leaf (which was available) was not selected; • More than one mistletoe was available in the normal home range of the monkey, but selection was dominated by one mistletoe/host combination; • Consumption was of relatively small volumes; • There was an apparent seasonality to the use of mistletoe; • Consumption of mature, mistletoe leaf occurred at times when there was no shortage of suitable fruit; • Limitations of the Ateles spp. digestive system made exploitation of mature leaf potentially problematic; • The monkeys were also seen consuming geophageous material; on occasion, this closely followed mistletoe consumption; • There were no published reports of Ateles spp. geophagy in Central America and/or tropical dry forest habitat. The aim of the subsequent investigation was to determine if there was any beneficial function that could be attributed to the materials and so provide a link to a self-mediation hypothesis for mistletoe and/or geophagy or to relate the determined geophagy properties to the other published functional hypotheses for geophagy. The novel aspect of this project was the development of a specific ‘gastric model’ reflecting the differences between Ateles and human digestive systems. This modified model was used to investigate geophagic and Phoradendron samples. It was hoped that this approach would lead to the identification or constituents in the samples, which may have physiological significance. Samples of the two species of mistletoe identified were collected from three Phoradendron/host tree combinations. Samples were extracted using the simulated gastric conditions and the extracts analysed. Analytical ‘fingerprints’ of the gastric extracts of the two species were obtained together with the antimicrobial activities of the extracts. Species variation in Phoradendron constituents and antimicrobial activity was detected. The principal difference between the eaten and non-eaten Phoradendron species was identified using HPLC and LC-MS, as chlorogenic acid. Chlorogenic acid has antibacterial and antioxidant properties, stimulates the immune system and has activities related to regulation of blood sugar levels. Phoradendron consumption wass during the wet season, which may be a period of increased bacterial and parasite infection. It also coincides with a change in dietary fruits. The geophagic samples were taken from sites previously used by Ateles, together with ‘control’ sites found in the home range of the study group. Analysis of the physical properties and characteristics was undertaken to attempt to identify the mineral content material. Further analyses then investigated the behaviour of the material in relation to the commonly accepted hypotheses for geophagy. Where possible these were investigated using the simulated gastric conditions. The physical characteristics of the samples did not resemble the previously published reports for geophagic material used by humans or non-human primates. The results failed to detect the presence of montmorillonite and only a suggestion of the presence of kaolinite. The results do not suggest that it functions as an antacid, an anti-diarrhoeal or mineral supplement. An increase in antibacterial activity was seen when geophagic material and Phoradendron samples were incubated together. A putative hypothesis for the mechanism of Fe limitation was suggested by the physical properties of the geophagic material and the Fe chelating potential of the chemical constituents of the Phoradendron leaf.

Identiferoai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:644375
Date January 2014
CreatorsRostron, Lynda Ann
ContributorsRostron, Christopher ; Aurelli, Filippo ; Jones, Jenny
PublisherLiverpool John Moores University
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Sourcehttp://researchonline.ljmu.ac.uk/4473/

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