DOI: 10.5061/dryad.hhmgqnks7
title: Risk-sensitive foraging in a tropical lizard

description: Foraging opportunities can be unpredictable. When foragers face a choice
 between resources that vary in predictability, foraging decisions not only
 depend on the profitability of food but also on their physiological state.
 This risk-sensitive foraging approach, in which animals take greater
 foraging risks when starving, remains relatively untested in reptiles
 compared to other taxa. We tested the risk-sensitive foraging theory in
 the tropical lizard, Psammophilus dorsalis, by manipulating energy budgets
 (satiated vs. 48-hour starved) and measuring foraging preferences for
 options that differed in rewards: constant (2 mealworms) vs. variable (0
 or 4  mealworms). We find that satiated lizards were risk averse
 to variability in reward amounts and chose the constant food option more
 frequently than the variable option. By contrast, starved lizards were
 risk prone and chose the variable reward option more often than the
 constant one. At the end of 28 foraging trials, these strategies resulted
 in both starved and satiated groups achieving similar net resource gains.
 As new support for risk-sensitive foraging in a tropical reptile species,
 these results provide insight on how resource uncertainty influences
 foraging strategies. For lizards in the tropics, which have high energy
 requirements year-round, risk-sensitive foraging could be an effective
 strategy in stochastic environments.
description: We tested the risk-sensitive foraging theory in the tropical
 lizard <em>Psammophilus dorsalis</em>. We conducted a choice
 experiment with adult lizards of both sexes. In the experiment phase,
 lizards were subjected to different starvation treatment (satiated vs
 48-hour starved). Morphometric measurments such as snout-vent length and
 body mass were measured before and after the experiment phase. During the
 experiment phase, lizards were also tested for their foraging choice
 between two food options which provided variable rewards (constant vs.
 variable number of mealworms).
description: Title of dataset: Risk-sensitive foraging in a tropical lizard Authors:
 Avik Banerjee1, Maria Thaker1 Affiliation: 1Centre for Ecological
 Sciences, Indian Institute of Science, Bengaluru, India The data files
 contains data on number of choices made, number of mealworms eaten and
 mass difference for both satiated and starved state lizards. ##
 Description of the data and file structure 1. "Supplement 1_Risk
 sensitive foraging_Datasheet" excel file: [Convert it to .csv file
 for use in the analyses with the R codes]. This excel file includes the
 following data: Sheet 1 Column 1 consists of the lizard ID (or unique
 identifier). Column 2 indicate the sex of the lizard ('F' for
 females and 'M' for males). Column 3 indicate the starvation
 state of the lizard ('SATIATED' for satiated lizards and
 'STARVED' for 48-hour starved lizards). Column 4 indicates the
 choices available during the testing phase. Column 5 indicates the number
 of times the choice in Column 4 was made during the testing phase. Sheet 2
 Column 1 consists of the lizard ID (or unique identifier). Column 2
 indicate the sex of the lizard ('F' for females and
 'M' for males). Column 3 indicate the starvation state of the
 lizard ('SATIATED' for satiated lizards and 'STARVED'
 for 48-hour starved lizards). Column 4 and 5 indicates the initial (before
 experiment) and final (after experiment) Snout-Vent-Length (SVL, in mm) of
 the lizards respectively. Column 6 indicates the total number of mealworms
 gained (count) as rewards during the testing phase. Column 7 and 8
 indicates the initial (before experiment) and final (after experiment)
 mass  (in grams) of the lizards respectively. Column 9 indicates the
 difference in mass (final mass - initial mass) (in grams) for lizards. 2.
 "Supplement 2_Risk sensitive foraging_Rcode.R" : includes all R
 codes with step-by-step comments to replicate the analyses. 3. A video
 named "Supplement 3_Risk sensitive foraging_Video" showing a
 male P. dorsalis lizard making a choice during the testing phase is
 provided.