Fruiting trees provide fruit and insect resources for four tropical deer species
Data files
May 01, 2024 version files 29.59 KB
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Bug_counts.xlsx
10.74 KB
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Insect_consumption.xlsx
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README.md
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Abstract
Fruiting trees provide important fruit and seed resources for various animal species, but rarely are they considered to be rich sources of insects as well. During a study of seed dispersal of Trewia nudiflora (Euphorbiaceae) using camera-traps in Nepal, we observed four tropical deer species (Axis axis, Muntiacus vaginalis, Rusa unicolor, Axis porcinus) foraging for insects, rather than fruits under the trees. These herbivorous deer are proven seed dispersers of Trewia, but 8-38% of video captures (across each species) were of insectivory, rather than frugivory. The deer chased and consumed red cotton bugs (Dysdercus sp. family Pyrrhocoridae), which were seed predators that hoarded Trewia seeds. It is likely that other unidentified insect species were also consumed. Tropical deer species are considered to be fully herbivorous, so our observations extend their known diets and possibly indicate a seasonal requirement for protein. These findings also highlight tri-trophic interactions among deer, insects, and fruits that could have important implications for seedling recruitment if seed predators are being consumed by seed dispersers (in addition to fruit consumption).
README: GENERAL INFORMATION
Fruiting trees provide fruit and insect resources for four tropical deer species
Two datasets are provided in relation to insect consumption by four tropical deer species (Axis axis, Muntiacus vaginalis, Rusa unicolor, Axis porcinus) in Chitwan National Park, Nepal. The first dataset (Insect_consumption) provides details on insect consumption by deer collected from camera-traps in 2020 and 2021. Cameras were set-up under 75 fruiting Trewia nudiflora (Euphorbiaceae) trees when fruit were at their peak abundance (August to October), primarily to collect seed dispersal information for the animal community. However, red cotton bugs (Dysdercus sp. family Pyrrhocoridae) consume the seeds of the fruit and these were the main insect chased and consumed by the deer. The first dataset reports all details recorded for the insect-eating events. The second dataset (Bug_counts) report the number of red cotton bugs in one square meter plots (averaged across four plots per tree) for 20 fruiting *Trewia nudiflora *trees. The plots were placed along the cardinal direction (east, north, west, south) around the tree and under the canopy.
Citation for publication in which the data were used:
Awasthi B, Chen J, McConkey KR, (in press). Fruiting trees provide fruit and insect resources for four tropical deer species. Ecosphere.
DATA-SPECIFIC INFORMATION
Dataset 1. Insect_consumption
Animal species: common name of the deer observed to consume insects
Genus_species: Genus and species name of the deer
Year: 2020 or 2021
Tree ID: unique code for each tree. Letters specify study area and numbers specify tree ID. Study areas within Chitwan National Park are:** **IT-Icherney, J- Jayamangala
Date: Date of video recorded
First video time: the start time of video recorded.
Visit length (min): total length of an independent visit in minutes
No. of individuals observed: Number of individuals of the deer species observed in the video
Fruit-eating observed (1=yes, 0=no): if deer was also observed to consume fruits as well as insects then 1 was recorded. If only insects were eaten then 0 was recorded.
Insect-eating (1 = confirmed or 2 = likely): Confirmed feeding was noted when the insect could be clearly distinguished in the video (1=confirmed) and Unconfirmed feeding was noted when the deer was feeding on something other than the easily-identifiable fruit or vegetation; in many of these videos insects can be seen moving away from the deer as they forage, but insect-capture could not be confirmed (2=likely)
Dataset 2. Bug_counts
Tree ID: unique code for each tree for which data were collected. These are not the same trees as in Dataset 1.
East_count: number of red cotton bugs counted in one square metre under the tree canopy to the east.
North_count: number of red cotton bugs counted in one square metre under the tree canopy to the north.
West_count: number of red cotton bugs counted in one square metre under the tree canopy to the west.
South_count: number of red cotton bugs counted in one square metre under the tree canopy to the south.
Mean count of RCB per sq m: Average (mean) of red cotton bugs across all four plots.
Chitwan National Park
The field study in Chitwan National Park in Nepal (latitude 27.537241, longitude: 84.447945) in 2020 and 2021, from August to October when Trewia nudiflora (Euphorbiaceae) fruit were at their peak abundance. Chitwan covers an area of 952.63 km2 in the Terai Arc Landscape of Nepal and has an altitudinal range of 150-800 m (Awasthi et al., 2023).
References
Awasthi, B., Lamichhane, B.R., MacConkey, K.R. 2023. Plastic ingestion by greater one-horned rhinos in Nepal: an emerging conservation threat*. Global Ecology and Conservation* 46: 1-6. https://doi.org/10.1016/j.gecco.2023.e02549.
Karar, H., Bashir, M.A., Khan, K.A., Ghramh, H.A., Atta, S., Ansari, M.J., Ahmad, Z., Khan,F.R. 2020. The impact of adjacent habitats on population dynamics of red cotton bugs and lint quality. PLoS ONE 15: e0242787. https://doi.org/10.1371/journal. pone.0242787.
Methods
Cameras were set-up under 75 fruiting trees of Trewia nudiflora to obtain information on its terrestrial consumers and seed dispersers. While monitoring the videos we noticed that not all deer feeding interactions were of fruit, and here we report confirmed and unconfirmed observations of insect feeding. Confirmed feeding was noted when the insect could be clearly distinguished in the video. Unconfirmed feeding was noted when the deer was feeding on something other than the easily identifiable fruit or vegetation; in many of these videos insects can be seen moving away from the deer as they forage, but insect-capture could not be confirmed. A) Camera trapping and b), counted the number of red cotton bugs in one square meter plots (averaged across four plots per tree) for 20 trees (Karar et al., 2020).