A DNA metabarcoding study of a primate dietary diversity and plasticity across its entire fragmented range

In tropical regions, most primary ecosystems have been replaced by mosaic landscapes in which species must cope with a large shift in the distribution of their habitat and associated food resources. Primates are particularly vulnerable to habitat modifications. Most species persist in small fragments surrounded by complex human-mediated matrices whose structure and connectivity may strongly influence their dispersal and feeding behavior. Behavioral plasticity appears to be a crucial parameter governing the ability of organisms to exploit the resources offered by new matrix habitats and thus to persist in fragmented habitats. In this study, we were interested in the dietary plasticity of the golden-crowned sifaka (Propithecus tattersalli), an endangered species of lemur, found only in the Daraina region in north-eastern Madagascar. We used a DNA-based approach combining the barcoding concept and Illumina next-generation sequencing to (i) describe the species diet across its entire range and (ii) evaluate the influence of landscape heterogeneity on diet diversity and composition. Faeces from 96 individuals were sampled across the entire species range and their contents were analyzed using the trnL metabarcoding approach. In parallel, we built a large DNA reference database based on a checklist of the plant species of the Daraina region. Our results suggest that golden-crowned sifakas exhibit remarkable dietary diversity with at least 130 plant species belonging to 80 genera and 49 different families. We highlighted an influence of both habitat type and openness on diet composition suggesting a high flexibility of foraging strategies. Moreover, we observed the presence of numerous cultivated and naturalized plants in the faeces of groups living in forest edge areas. Overall, our findings support our initial expectation that P. tattersalli is able to cope with the current level of alteration of the landscape and confirm our previous results on the distribution and the dispersal ability of this species

On the CO 2 sorption and swelling of elastomers by supercritical CO 2 as studied by in situ high pressure FTIR microscopy

An FTIR (Fourier Transform InfraRed) microscope combined to a high pressure cell has been used to determine the CO2 uptake in several common elastomers. Both the CO2 sorption and the resulting swelling of the elastomers have been determined as function of pressure (P = 5–15 MPa) at constant temperature (T = 50 °C). A significant quantity of CO2 is sorbed in all studied elastomers, between 15 and 20% at T = 50 °C and P = 15 MPa for most elastomers and up to 30% for Ethylene Vinylacetate (EVM) in the same conditions. The resulting percentage of swelling of the majority of studied elastomers is significant (up to 30%), and varies quite proportionally with the CO2 mass uptake (linear variation with a slope equal to 1). The effect of temperature has been studied for Ethylene Propylene Diene (EPDM), between T = 50 °C and T = 110 °C (P = 5–15 MPa) and demonstrate that the swelling and CO2 sorption display only a weak variation in this temperature range

Quemere_gh_sequence_data

This file contains all unique sequences produced by G/H primers and occurring more than once. The sequences have been produced by the Illumina technology (GA IIx platform)

Environmental determinants of diet composition.

<p>Biplots of the co-inertia analysis between the PCA of diet composition (presence/absence of the 130 taxa) and the PCA of landscape structure (% area of the six habitats within the circular buffers).</p

Relative proportion of the most important habitat types within <i>P. tattersalli</i> home ranges.

<p>Proportions were calculated within circular buffers of 500m of radius centered on the group sampling location. N_maj indicate the number of groups for which this habitat is the most represented.</p

Taxonomic resolution of the golden-crowned sifaka diet.

<p>Panel (a) presents the results base on the EMBL reference database only. Panel (b) presents the results using both EMBL and customized local reference database. Panel (c) uses the final results integrating the final validation by taxonomic experts. The proportions correspond to the number of sequences assigned to each taxonomic rank compared to the total number of identified sequences from DNA Barcoding (N = 130).</p

Quemere_gh_final_data

This file contains the filtered sequences produced by G/H primers. The sequences have been produced by the Illumina technology (GA IIx platform)

Faeces and plant sampling schemes.

<p>Faeces and plant sampling schemes.</p

Quemere_gh_final

This file contains the filtered sequences produced by G/H primers. The sequences have been produced by the Illumina technology (GA IIx platform)