DOI: 10.5061/dryad.m605m
title: Data from: A camera-based method for estimating absolute density in animals displaying home range behaviour

description: 1.The measurement of animal density may take advantage of recent
 technological achievements in wildlife video recording. Fostering the
 theoretical links between the patterns depicted by cameras and absolute
 density is required to exploit this potential. 2.We explore the
 applicability of the Hutchinson-Waser's postulate (i.e., when animal
 density is stationary at a given temporal and spatial scale, the absolute
 density is given by the average number of animals counted per frame),
 which is a counter-intuitive statement for most ecologists and managers
 who are concerned with counting the same individual more than once. We
 aimed to reconcile such skepticism for animals displaying home range
 behaviour. 3.The specific objectives of this paper are to generalize the
 Hutchinson-Waser's postulate for animals displaying home range
 behaviour and to propose a Bayesian implementation to estimate density
 from counts per frame using video cameras. 4.Accuracy and precision of the
 method was evaluated by means of computer simulation experiments.
 Specifically, six animal archetypes displaying well-contrasted movement
 features were considered. The simulation results demonstrate that density
 could be accurately estimated after an affordable sampling effort (i.e.,
 number of cameras and deployment time) for a great number of animals
 across taxa. 5.The proposed method may complement other conventional
 methods for estimating animal density. The major advantages are that
 identifying an animal at the individual level and precise knowledge on how
 animals move are not needed, and that density can be estimated in a single
 survey. The method can accommodate conventional camera trapping data. The
 major limitations are related to some implicit assumptions of the
 underlying model: the home range centres should be homogeneously
 distributed, the detection probability within the area surveyed by the
 camera should be known, and animals should move independently to one
 another. Further improvements for circumventing these limitations are
 discussed.
description: Species-level database
 of density, body mass, speed and home range size.This is a dataset
 compiled from bibliographic references (see Materials & Methods).
 Essentially, it includes information of density, body mass, speed and home
 range size for 44 species. Name variables (in columns) are defined as
 follows: “Species” (TEXT): scientific name of each species; “BM(g)”
 (NUMERIC): body mass in grams; “HR(Km2)” (NUMERIC): Home range size in
 square kilometres; “Refs(for_BM_and_HR)” (TEXT): data source for body mass
 and home range size data (see Appendix S3 in Supplementary Materials for
 full citations); “DENSITY(ind/Km2)” (NUMERIC): animal density in number of
 individuals per square kilometre; “Density_survey_method” (TEXT): details
 of the survey method used to estimate density (if available);
 “Surveyed_area” (NUMERIC+TEXT): details of the surveyed area when
 estimating density (if available); “Study_area” (TEXT): details of the
 area of study when estimating density (if available); “Refs(for_Density)”
 (TEXT): data source for density and density-related data (see Appendix S3
 in Supplementary Materials for full citations); “SPEED(ms-1)” (NUMERIC):
 speed in meters per second; “Speed_survey_method” (TEXT): details of the
 survey method used to estimate speed (if available); “Time_step”
 (NUMERIC+TEXT): time step used to estimate speed (if available);
 “Sampling_time” (NUMERIC+TEXT): total tracking time used to estimate speed
 (if available); “Refs(for_Speed)” (TEXT): data source for speed and
 speed-related data (see Appendix S3 in Supplementary Materials for full
 citations).JAECamposCandela_DATA.xls