Resource depletion through primate stone technology
- University of Oxford, United Kingdom
- Nanyang Technological University, Singapore
- Max Planck Institute for Evolutionary Anthropology, Germany
- Chulalongkorn University, Thailand
- National Primate Research Center of Thailand-Chulalongkorn University, Thailand
Figures
Figure 1
Tool weights of Koram and NomSao Islands.
(A) Comparison between weights of stones used by macaques on Koram and NomSao Islands to open oysters. The plot shows all quantiles and the CIs (grey). (B) Comparison between weights of stones used by macaques on Koram and NomSao Islands to open snails. The plot shows all quantiles and the Cis (grey).
-
Figure 1—source data 1
Stone tools used.
Shellfish foraging stone tools collected on Koram and NomSao Islands, Thailand.
- https://doi.org/10.7554/eLife.23647.004
Figure 2
Location of the two study islands (Koram and NomSao) in Khao Sam Roi Yot National Park, Thailand.
https://doi.org/10.7554/eLife.23647.005
Figure 3
Stones available on Koram and NomSao Islands.
(A) Weight of stones (with bootstrapped 95% confidence intervals) found on Koram and NomSao Islands, separated for oyster bed and tidal. (B) Average stone availability per island, separated for oyster bed and tidal (with bootstrapped 95% confidence intervals over observed plots).
-
Figure 3—source data 1
Natural stone availability and weight.
The number and weight of stones located in 20 × 20 cm plots on Koram and NomSao Islands, Thailand.
- https://doi.org/10.7554/eLife.23647.007
Figure 4
Average snail availability on Koram and NomSao Islands for three species (with bootstrapped 95% confidence intervals over observed plots).
https://doi.org/10.7554/eLife.23647.008-
Figure 4—source data 1
Snail availability.
The number of snails located in point transects along the shore of Koram and NomSao Islands, Thailand.
- https://doi.org/10.7554/eLife.23647.009
Figure 5
Prey size on Koram and NomSao Islands.
(A) Average size of oysters (with bootstrapped 95% confidence intervals) found on Koram and NomSao Islands. (B) Average snail size (volume) (with bootstrapped 95% confidence intervals) found on Koram and NomSao Islands.
-
Figure 5—source data 1
Oyster size.
The size of rock oysters measured in width and length on Koram and NomSao Islands, Thailand.
- https://doi.org/10.7554/eLife.23647.011
-
Figure 5—source data 2
Snail size.
The size (length) of three marine snails (N = 100 each) on Koram and NomSao Islands, Thailand.
- https://doi.org/10.7554/eLife.23647.012
Figure 6
Long-tailed macaque tool use.
(A) Adult male long-tailed macaque using a stone tool to crack open a snail. (B) Size difference between NomSao and Koram Islands of most commonly harvested snails. (C) Abandoned macaque tool at shellfish cracking site, with prey remains. (D) Recently harvested oysters (white) are clearly distinguishable from older oysters (grey).
Tables
Table 1
Life history information of main prey species.
https://doi.org/10.7554/eLife.23647.014| Factors influencing population resilience | Prediction | Rock oyster | Tropical periwinkle |
|---|---|---|---|
| Resource Aggregation/Clustering | High aggregation → slow recovery | High aggregation | High aggregation |
| Size and age at sexual reproductive maturity | Large size at sexual maturity → slow recovery | Large: first year grows 25 mm Able to reproduce in the first year | Small: first year grows 14 mm (17.44 mm second year). Reproduced in second year |
| Reproductive output (per individual) | High reproductive output → fast recovery | High (50 to 200 million) | Low (10.000–100.000) Only 2% survive until sexual maturity |
| Larvae stage | Attached → slow recovery | Unattached: Planctonic larvae | Unattached: Planctonic larvae |
Additional files
-
Source data 1
Koram Island shellfish foraging.
The number of prey items consumed during behavioral observation of daily shellfish foraging on Koram Island, Thailand.
- https://doi.org/10.7554/eLife.23647.015
-
Source data 2
Maturation stages.
The size and maturation stages of the main prey species harvested by tool using macaques on Koram and NomSao Island, Thailand.
- https://doi.org/10.7554/eLife.23647.016
Download links
A two-part list of links to download the article, or parts of the article, in various formats.
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Resource depletion through primate stone technology
eLife 6:e23647.
https://doi.org/10.7554/eLife.23647
