Incidencia síntomas del síndrome de afectación

difference in the amount of Ba released between the sites (Table 3.31). In this case a Dunn’s Multiple comparison test showed a significant difference in barium released between Ateles sites p<0.001.

There was no significant difference in the amount of Mn released between all the sites (Figure 3.49b and Table 3.31) and a Dunn’s Multiple comparison test showed no significant difference between Ateles sites p>0.05.

Zinc

Figure 3.50 ICP- MS determined zinc released from samples

Control site 4 Site 8 released the lowest level of zinc (Figure 3.50). There was a significant difference in the Zn released between all sites (Table 3.31) and a Dunn’s Multiple comparison test also showed a significant difference between Ateles sites p<0.001.

Table 3.31 Summary of Kruskal-Wallis 1-Way Anova, (all site comparisons) ICP determination of minerals released concentrations > LOQ.

KW statistic No, of groups p

potassium 30.15 6 <0.0001

magnesium 30.08 6 <0.0001

calcium 28.46 6 <0.0001

aluminium 19.29 6 0.0073

barium 13.25 6 0.0212

manganese 10.37 6 0.0653

zinc 11.49 6 0.0425

In summary:

o Only 7 elements were detected at levels above the LOQ.

o Only Site 2 had Na > LOQ

o K, Ca and Mg levels varied significantly between all the sites o Al, Ba, Mn and Zn did not vary significantly between all sites

o K, Ca, Ba and Zn showed a significant variation between the known Ateles eating sites o Mg. Al and Mn showed no significant variation between the known Ateles eating sites

3.5.10.2 Adsorption of Fe

The normalised calibration data was plotted using the Fe⁵⁸ data, (y= 0.0207x + 0.0163; R2 = 0.9989), the LOD and LOQ were determined.

The Fe recovery for the spiked blanks was 98.66-97.98%. The residual Fe levels were determined for each sample. Values for each sample were calculated and plotted in Excel 2010©. Due to limitations in sample available it was not possible to conduct sufficient analyses to permit statistical analysis to be undertaken.

0 2 4 6 8 10

Site 1 Site 2 Site 4 Site 6 Site 9 Site 10

μg/g

zinc

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Figure 3.51 ICP- MS determined Fe adsorbed from spiked solutions, pH2 conditions, highlighting Ateles eating sites.

The results however suggest that there will be adsorption by the geophagy samples of Fe in both acidic/gastric (Figure 3.51) and also in the intestinal pH7 conditions (Figure 3.52).

Figure 3.52 ICP- MS determined Fe adsorbed from spiked solutions, pH7 conditions.

The Fe released in samples from the sites <LOQ in previous ICP-MS analysis of geophagy samples in acidic conditions, therefore there is likely to be little contribution from the geophagy samples to the measured values remaining in solution in these spiked analyses. At low pH or in anoxic conditions the more soluble ferrous (Fe²⁺) form is present in aqueous solution.

The data presented in Figure 3.52 suggests that soluble Fe is exchanged/adsorbed or lost. This may be due to formation of insoluble iron hydroxides under the pH 7 conditions (Schwertmann et al. 1989).

3.5.11 Microbiological Assessment of geophagy samples

The plates were examined after incubation for 7 days, there was no growth indicating there was no viable bacterial contamination. The plates were then returned to the incubator for a further 21 days. There was no growth after this extended period indicating that no viable fungal spores were present.

0 100 200 300 400 500 600 700

Site 1 Site 1 Site 2 Site 2 Site 4 Site 4 Site 6 Site 6 Site 6 Site 8 Site 8 Site 9 Site 9 Site 10

adsorbed Fe ppm/250mg geophagy sample pH2 conditions

0 200 400 600 800 1000

Site 1 Site 1 Site 2 Site 2 Site 4 Site 4 Site 6 Site 6 Site 6 Site 8 Site 8 Site 9 Site 9 Site 10

Adsorbed Fe ppm/250mg geophagy sample pH7 conditions

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3.6 Discussion of Results

The results are discussed in the context of previous publications and the main functional hypotheses for geophagy. A summary of the analytical outcomes are presented in Table 3.32.

Table 3.32 Summary of analytical outcomes

Technique- characteristic determined Outcomes

Munsell colour characteristic consumed samples pink/grey Loss on Ignition/ presence of carbonates/organic

material

very low levels organic carbon or carbonates

XRD –presence of clay or other minerals quartz, feldspars, amorphous minerals minimal kaolinite absence of montmorillonites, limited magnetite and maghemite

IR – presence of clay minerals/organic matter/water

quartz, feldspars, amorphous minerals minimal kaolinite absence of montmorillonites

XRF– detectable elements present acidic nature derived from andesite/dacite type volcanic rocks;

aluminium values

ICP– of elements released into gastric extract limited elements reached LOQ, variable levels across the sites ICP-Effects of geophagy material on potentially

available Fe

Fe levels reduced when incubated in presence of geophagy material

Laser diffraction particle size in variable pH-media conditions/presence of clay sized particles

8-9% clay –very fine silts (<4μm); 18% fine, medium and coarse silts (4-32 μm)17-25% coarse, very coarse sand (500 μm) in Ateles eaten sites

Sample pH in water and KCl solution acidic in nature UV– analysis of gastric extract following exposure

to example PSM in gastric conditions

Ateles sites 200mg samples adsorbed < 50mg kaolinite or 10-25mg montmorillonite

Microbiological screening of gastric digest no organisms cultured

3.6.1 Munsell Colour characterisation

A review of the literature of geophagy material published since 1999 is collated in Table 3.33. This indicated that soils consumed by primates were predominantly reddish to reddish brown in colour. The yellow red colours indicate that eaten soils were highly weathered and depleted in silica (Krishnamani et al. 2000) due to prolonged leaching, together with the presence of oxides high in Fe (Mahaney et al. 1995a, Mahaney et al.

1996, Mahaney et al. 1997). The yellow colours often indicate released hydroxides of iron or aluminium and signify high clay content (Krishnamani et al. 2000). Hematite, formed by dehydration of goethite (Schwertmann et al. 1989), is abundant in ancient red beds whereas goethite is abundant in younger yellow-brown coloured deposits.

Detection of geophagy material by colour is available to humans, Old world apes and monkeys who share trichromatic colour vision (Sumner et al. 2000). Trichromatic vision has both a red-green chromatic channel and blue-yellow channel. New world primates differ in that there are sex-linked polymorphisms. In many cases males are obligate dichromats and females may be either dichromatic or trichromatic colour vision (Jacobs 2007). Investigation of the polymorphism in Ateles geoffroyi has been undertaken at Santa Rosa (Hiramatsu et al. 2005, Hiramatsu et al. 2008). Detection and selection (based on colour alone) of red coloured geophagy samples by Ateles geoffroyi would therefore be limited to trichromatic females.

Geophagy reports in New World primates are predominantly behavioural and there are few reports of sample or colour characterisation (Ferrari et al. 2008). New World monkeys often consume soil from arboreal sources, such as termite nests and ant mounds and wet/salido material.

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Table 3.33 Examples of publications relating to primate geophagy since 1999.

Reference Ape species Colour

Aufreiter et al. (2001) Pan troglodytes schweinfurthii Yellow-red 10YR 5/6 bright brown-orange 7.5YR4/6**

Ketch et al. (2001) Pan troglodytes schweinfurthii Not reported Klein et al. (2008) Pan troglodytes schweinfurthii red

Mahaney et al. (1999) Pan troglodytes schweinfurthii Yellow-brown 10YR 5/4 – 7.5YR 5/6 bright brown eaten

Mahaney et al. (2005) Pan troglodytes schweinfurthii 2.5YR 4/6 yellowish red – 10YR 4/3 yellow brown-grey

Reference Old world species colour

Mills et al. (2007) Papio ursinus Bright yellow brown (10YR 7/6) bright red brown (5YR 5/6) grey yellow (2.5YR 6/2)

Pebsworth et al. (2012) Papio cynocephalus ursinus White pink; ochre/pink no hue/chroma classification Pebsworth et al. (2013) Papio cynocephalus ursinus White, no hue/chroma classification

Voros et al.(2001) Macaca radiata 5YR 4/8 reddish brown 5YR 5/8 bright red brown**

Wakibara et al. (2001) Macaca fuscata No colour reported Reference and New world primate species

No reports of colour in these publications

Adams et al.(2011) Pithecia irrorata; Blake et al. (2010, 2011, 2013) Ateles belzebuth Campbell et al. (2005), Ateles spp.; De Souza et al.(2002), Alouatta belzebul; Dew (2005) Ateles belzebuth belzebuth; Molina Gonzalez (2010) Alouatta seniculus; Link et al. (2006, 2011a, 2011b) Ateles hybridus; Molina et al. (2014) Alouatta seniculus;

Montenegro (2004) Ateles paniscus.

The results for the Santa Rosa samples (Section 3.5.1, Table 3.17) are the first colour characterisation of geophagy materials for New World primate species. The eaten material was light grey-pinkish grey colours.

Pebsworth (2013) reported an example of consumption in an Old World primate of white coloured material which had lower Fe content than a rejected pink soil. The report also showed that there was a low bioavailability of Fe from both eaten and non-eaten samples. This illustrates the importance of not relying on total element content when suggesting a function. Colour can be used to infer presence but not bioavailability (Fontes et al. 2005). The colour of the Santa Rosa samples suggests that there is unlikely to be significant amounts of Fe in the sites chosen by Ateles.

In summary:

The Santa Rosa sample colours were markedly different from those in the bulk of the published literature for primates.

3.6.2 Mineral Content

The results from these analyses: XRD, Section 3.5.4, IR Section 3.5.5 and XRF Section 3.5.6 were used to characterise the mineral content.

The XRF data from Rockwood suggest the materials from Santa Rosa belong to the andesite/dacite groups of minerals (Appendix 1.2 Glossary of Geological terms). This is based on the TAS diagram classification (Figure 3.34). Andesites have SiO2 content 52%-63% and dacites 63-68%, this is consistent with the Santa Rosa data (Table 3.26). The feldspar constituents of andesites produce pink grey coloured material (McGraw-Hill 2003). XRD results indicate the presence of quartz, feldspars and traces of halloysite, kaolinite and the iron minerals maghemite and magnetite in the Ateles eating sites. These results agree with the minerals of andesitic volcanic lavas in Costa Rica identified by van Dooremolen et al. (1990) who describe poorly sorted lahars composed of kaolinite, illite, both 0.7 and 1.0nm halloysite, goethite and gibbsite.

Halloysite, metahalloysite are species of kaolin minerals with similar structure to kaolinite. Kaolinites are

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