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Dryad

Frugivory and seed predation of fishtail palm (Caryota mitis Lour.) on the remote oceanic island of Narcondam, India

Cite this dataset

Gopal, Abhishek et al. (2024). Frugivory and seed predation of fishtail palm (Caryota mitis Lour.) on the remote oceanic island of Narcondam, India [Dataset]. Dryad. https://doi.org/10.5061/dryad.4tmpg4fjj

Abstract

Oceanic islands, due to their evolutionary history and isolation, play a dual role of having high endemicity and being vulnerable to extinctions, with most known extinctions occurring on islands. Plant–animal interactions are particularly important on islands, as island systems generally have low redundancy and are more vulnerable to disruption either via extinction or by invasive species. Here, we examined the fruit removal and seed predation of a keystone palm, Caryota mitis, on Narcondam, a remote oceanic island. The island endemic Narcondam Hornbill (Rhyticeros narcondami) was the sole seed disperser of the palm (90 hours; N = 15 trees), with mean (± SE) visitation rate being 0.23 (± 0.06) individuals per hour and fruit removal rates of 3.5 (± 1.5; range: 0–16) fruits per visit, indicating a lack of redundancy in seed dispersal of the palm on this island. Whereas the invasive rodent, Rattus cf. tiomanicus, was the sole predator of palm seeds (N = 15 individual fruiting palms, 416 trap nights). Overall, 17.1% of the seeds placed (N = 375 seeds) were removed. Seeds placed under and away from the canopy, and at different densities (2 plots with 10 seeds each; 1 plot with 5 seeds, respectively), showed similar removal rates. This indicates density-independent seed predation and the lack of safe regeneration sites for Caryota mitis, with potential deleterious effects on subsequent stages of the ‘seed dispersal cycle’. Here, from a data-deficient site, we provide baseline information on the plant–frugivore interaction of a keystone palm and the potential impacts of an invasive rodent.

README: Frugivory and seed predation of fishtail palm (Caryota mitis Lour.) on the remote oceanic island of Narcondam, India

https://doi.org/10.5061/dryad.4tmpg4fjj

Description of the data and file structure

This dataset reports the seed fates to the seed plots set up in the study.

The .csv file contains the seed fate of the 7 species examined in the study.

tree_sp: Name of the seven tree species that were part of the study

tree_code: Unique id number for each of the tree under which the seed plots were set up

lat: Latitude of the tree sampled

long: Longitude of the tree sampled

elev: Elevation in metres

start_date:  Start date of the seed monitoring session

end_date: End date of the seed monitoring session

days_monitored: Number of days seed plots were surveyed

plot_code: Code for the plot for each of the treatment type

type: These represent the three treatments: Away_high and Away_low plots 15m away from the focal tree with 10 seeds and 5 seeds respectively, and Canopy, plots under the canopy with 10  seeds.

Intact: Seeds which have remained as it is in the plot.

Removed: Seeds which have been predated or removed from the plot.

Funding

Wildlife Conservation Trust

Nature Conservation Foundation

Mr Uday Kumar

M. M. Muthiah Research Foundation

Mr Rohit and Deepa Sobti

Mr Aravind Datar

IDEAWILD