DOI: 10.5061/dryad.rbnzs7hm3
title: Data from: The effect of sampling schedule on assessment of dietary measures: Evidence from blue monkeys (Cercopithecus mitis stuhlmanni)

description: Accurately assessing primate diets is important in studies of behavioral
 ecology and evolution. While previous research has compared sampling
 methods (scan, focal), we compiled a data set to examine how sampling
 schedule influences accuracy of dietary measures. We define sampling
 schedule as the combined distribution (random vs. consecutive) and
 frequency of sampling days within a given month. Under field conditions,
 time may be required to locate a study group, and we therefore also
 subtracted 1, 2, or 3 hours from the beginning of all non-consecutive days
 in each sampling schedule to mimic observation time lost to search. From a
 dense (near daily) 5-year record of feeding behavior derived from focal
 animal follows of adult females in five wild blue monkey (C. m.
 stuhlmanni) groups, we created data subsets matching various sampling
 schedules, and compared monthly dietary measures calculated from each
 subset to those based on the full dataset. These measures included (1) the
 proportion of observation time feeding on fruit, (2) diet composition
 (three top-ranked food items), (3) species richness of plant diet, (4)
 Shannon-Weiner Diversity Index based on plant species, and (5)
 Holmes-Pitelka Index expressing dietary overlap (plant species) with the
 previous month. We used linear mixed models to assess how frequency and
 sampling type (a combination of distribution and hours lost) relate to a
 subset’s deviation from the full dataset, where a smaller deviation (or
 higher chance of matching, for diet composition) implies greater accuracy.
 The data set presented here is the full data set from which subsets were
 extracted for these analyses.
description: Data were collected from 2012-2016 through field observation of 5
 groups of wild blue monkeys (<em>Cercopithcus mitis
 stuhlmanni</em>) in Kakamega Forest, Kenya. On a near daily
 schedule, trained observers conducted 30 minute focal follows of adult
 females, balancing observation time across individuals and time of day
 (morning, midday, and afternoon periods). During follows, observers made
 instantaneous records (on the beep of a timer) of the subject’s activity
 at 1-minute intervals. Observers recorded a subject as feeding only when
 she put a food item in her mouth within 2 sec of the beep. Further details
 can be found in the methods section of the associated
 publication.
description: # Data from: The effect of sampling schedule on assessment of dietary
 measures: Evidence from blue monkeys (Cercopithecus mitis stuhlmanni)
 [https://doi.org/10.5061/dryad.rbnzs7hm3](https://doi.org/10.5061/dryad.rbnzs7hm3) ## Usage Notes: The dataset derives from focal animal follows of all adult females in five blue monkey groups from 01/01/2012 - 12/31/2016 and expresses the amount of sampling time that these subjects engaged in feeding vs. other behavior, as well as what foods (item, and plant species for plant-foods) were consumed. Each record indicates a unique combination of values in the N columns of the data set, which are as follows: * **group**: identity code of social group from which the record came. Data came from five groups observed throughout the observation period of five years. * **date**: calendar date (yyyy-mm-dd) on which the observations were made * **start_time**: time of day when focal follow started, expressed as hour of day using decimal notation. For example, 9.50 corresponds to 09:30 AM, and 15.25 corresponds to 15:15 PM. * **obs_hour**: designates the observation hour of the date given in date column. “1” designates the first observation hour of the day (i.e., within 60 minutes of the start of that day’s first focal follow of any subject in the same group), “2” designates the second observation hour for that group and day, “3” designates the third observation hour for the group and day. Values greater than 3 are all coded “4+”, meaning that the data came from the fourth or greater hour of observation for that group and day. This variable was used to exclude observations coded in the first hour, the first 2 hours or the first 3 hours of the day in some analyses, thus mimicking time lost to searching for the group of monkeys. * **activity**: F (feeding) or other (not feeding). * **item**: coded only when activity=F, with the following codes: fr (fruit), lvs (leaves, both mature, young, leaf buds and petioles), other_plant (plant parts other than fr or lvs, for example flowers, seeds, bark, among others), or ins (invertebrates, mainly insects). NA indicates missing values, assigned when activity was not “F”. * **food_plant**: coded only when activity=F, but not all feeding records included a food plant, because of visibility limitations in the rain forest habitat of the study animals. Each four letter code indicates a unique plant species. NA indicates missing values. * **beeps**: total count of beeps in which other values in this row of data applied. Each beep represents one instantaneous record in a focal follow of one female focal animal