# Online workshop: analysis of camera trap data with distance sampling, October 2022

Camera traps are widely used for studying terrestrial animal populations. Several methods exist for analysis of camera trap data to estimate animal abundance. Use of distance sampling theory for analysis of camera trap data does not require identification of individual animals to estimate abundance, making it applicable to a much larger set of species. This workshop, through lectures and computer exercises, provides training in survey design and the analysis of camera trap data to produce abundance estimates.

## Overview

The training workshop is intended to teach the fundamental principles of design and analysis of animal abundance using data derived from camera traps. In association with the principles, computer exercises will guide participants through survey design, fitting detection functions to detections, performing model selection, estimating temporal availability of animals and computing measures of uncertainty. The workshop will build upon a foundation of “conventional” distance sampling, and so workshop participants are expected to understand the basic concepts behind distance sampling before coming to the workshop (see “Prerequisites” below).

## Timing

10th – 14th October 2022, 14:00-17:00 UK time (BST, British Summer Time). To find the time in your location, follow this link to a universal time converter.

## Enrollment limit

Registration is limited to 15 participants, to allow us to run the workshop with participant involvement.

## Format and Delivery method

The workshop will be a mix of live online interactive sessions, delivered via videoconference software (Microsoft Teams) and computer exercises. There will be four sessions, across five days, each lasting three hours. In addition, there will be practical exercises to be undertaken outside of the scheduled sessions, with some to be completed in advance of the workshop starting. The practicals will be carried out using either Distance for Windows or the Distance package within the R statistical software.

## Content

Workshop content is given below; exact timing of topics may be changed.

• Day 1. Provides the foundation of distance sampling. The first computer exercise focuses upon analysis of point transect data (from a songbird survey) to initiate participants in fitting detection functions, assessing model fit and performing model selection. The second half of the session describes fundamentals of applying distance sampling analyses to camera trap data. The computer exercise associated with this topic (and subsequent topics) uses data on Maxwell’s duikers from the 2018 paper:
• Howe, E. J., Buckland, S. T., Després-Einspenner, M.-L., & Kühl, H. S. (2018). Distance sampling with camera traps. Methods in Ecology and Evolution 8:1558–1565. DOI
• Day 2. This day (as with days 3 and 5) will begin with a question and answer session to allow participants to raise any points that require further clarification related to the lectures or computer exercises on Day 1. The lecture/exercise topic of the day deals with design of camera trap surveys. The second half of this day is devoted to a discussion of the workflow associated with analysis of camera trap data, beginning with manipulation of images from SD camera cards to files ready for import into Distance for Windows.
• Day 3. After the question and answer session, the first lecture/exercise of the day is devoted to the special problem of model selection that arises with camera trap data, possibly caused by over-dispersion in the distribution of detection distances. Methods for refining model selection in this situation is described and applied to the duiker analysis from Day 1. The second topic of the day is assessing temporal availability of the study animal and ways to incorporate the estimate of temporal availability (and the uncertainty in that estimate) in the estimation of animal abundance.
• Day 4. There is no formal meeting on this day. Instead, participants will have time to complete any outstanding practical exercises and formulate questions to pose on the final day of the workshop.
• Day 5. Following an open question and answer session, lecturers and participants will discuss animal reaction to cameras; how to detect and mitigate. Next will be two periods to discuss special topics. Those are topics nominated by participants for additional discussion, lead by the instructors. Following a break, the workshop concludes with additiona time to use as instructors determine.

## Prerequisites

You should already understand distance sampling concepts, for example by having taken a face-to-face introductory workshop or an online workshop (either interactive or via our free pre-recorded lectures). You should be familiar with the use of either the software Distance for Windows or the Distance package within R for distance sampling analysis.