Animal Counting Toolkit Checklist

Animal Counting Toolkit Checklist

Here is a list of the software and other suggested items you may want to have on hand as part of your Animal Counting Toolkit. Please know this list is not exhaustive, and we’re not endorsing any particular hardware or software. These are resources we’ve found handy. We’d love to hear what works for your fieldwork.

General approach

Please refer to our Animal Counting Toolkit paper and its supporting information file for complete details, but here is a general overview of the steps we follow. Watch Video 1 to learn about our approach and intended audience.

Defining a survey region

  • Watch Video 2
  • Clarify your research question. Distance sampling estimates the average number of animals in the survey region during your survey. Start your study by defining your study area. If you’re interested in identifying critical habitat or informing marine spatial planning, you may want to survey a broader area than just the boundaries of a marine protected area. 
  • Use geographic information system software to draw a polygon around your study area. We like the free QGIS software. 
  • Export the shapefile to Distance software.

Designing a survey to provide representative coverage of the survey region

  • Watch Video 3. Note that in this video, the grey polygons represent water, and the white represents land in the geographically complex waters of inshore British Columbia, Canada.
  • We illustrate our survey using a survey design of a grid of parallel lines with a random start point. This approach is often a good approach for small-boat surveys, because it gives even coverage probability, but is sometimes inefficient. 
  • For an in-depth, how-to guide on survey design, check out this paper and the Distance Sampling online tutorial for more information. The paper discusses line spacing, the advantages of parallel versus zigzag samplers, and many other fundamental concepts.
  • Program Distance has the ability to simulate coverage probability (i.e., does every point in your study region have the same probability of being sampled using the design). Even coverage probability is an assumption underlying a standard distance sampling analysis – without even coverage probability you may get biased results, unless more sophisticated analysis options are chosen.
  • Transects should not be placed parallel to coasts, riverbanks, depth contours, or any other feature that may be correlated with animal density. There is an assumption in distance sampling that transects are placed randomly with respect to local distribution of animals, so that animals are uniformly distributed with respect to distance from the trackline. Again, check out the Distance Sampling online course for a deep dive on this.

Field data collection

  • Watch Video 4
  • Revisit your research question. Are you trying to measure absolute abundance? Relative abundance of multiple species? Do you have a priority species in mind? This affects your field protocols. Check out papers here and here for approaches we’ve taken in our previous small-boat surveys. The advice by Dawson et al. (2008) is excellent, and has inspired our work in this field. 
  • In one of our applications on Amazon river dolphins with Fundacion Omacha, we found that collecting data to generate consistent indices of relative abundance would be helpful to inferring trends. If you have “inherited” data from a previous study, check out this paper for a discussion about the challenges of salvaging data to explore trends.
  • We illustrate our Animal Counting Toolkit using CyberTracker for data collection, and the supporting information file contains a CyberTracker template for data collection. In previous studies, we’ve used IFAW’s Logger program, and other software packages work well. You can also collect effort and sightings data on paper data forms. If you use paper forms, (a) we recommend use of a GPS to record effort, so you can calculate the length of transects actually surveyed (rather than the length of the transects you planned to survey), and (b) we recommend you scan or photograph data sheets frequently to avoid loss of data. 
  • The video refers to an angleboard. Here is a picture of what an angleboard looks like. We’ve included an image of a protractor you can download, print, laminate or waterproof, attach to a board, and mount to the bow of the boat. Attach a pointer to point at each sighting, and make sure that the 0º mark lines up precisely with the centerline of the boat, so it corresponds exactly to the boat’s track. During the survey, the observer points the pointer at each sighting, and this will help you avoid “rounding” the radial angle of each sighting to the nearest 5 or 10º. Again, this is described in the methods section of the Animal Counting Toolkit paper (and in this one).
  • It is essential to have unbiased estimates of the distance to each sighting. Search well ahead, so that you have recorded radial distance and angle to each sighting before the animal has responded to the boat. On a small boat, you may have a low platform. Check out this paper for ideas on building platforms to increase observer eye height to increase the observers’ field of view. If you are able to see the horizon, you can use reticle binoculars. You may be able to use rangefinders on some species. For others, you may have to conduct distance estimation experiments to investigate accuracy and precision of your observers’ ability to judge distance and to develop correction factors for bias in visual estimates.
  • Reminder: We have covered field protocols in detail in two key papers: here and here. Are there specific questions you have? Get in touch, and we will try to brainstorm ideas together.

Analyzing the data to estimate animal density and abundance

Software

Here are a few software files we like to use in our Animal Counting Toolkit, which you can download for free from these developers:

  • Distance the industry-standard software for line transect surveys.
  • CyberTracker for field data collection from a GPS-enabled handheld computer. We use CyberTracker to illustrate how to use our Toolkit, but have enjoyed using IFAW’s Logger software on larger boats with room to run a laptop.
  • Quantum GIS for mapping study area and sightings data.

Hardware

Here are some items you might find useful for small-boat surveys:

  • Range Finder, such as LaserWorks Long Distance up to 1,200 yards. This is helpful to get accurate distances to fixed objects in real time (e.g., seals hauled out on rocks), or to conduct distance estimation experiments to generate correction factors for visual estimates of radial distance. 
  • Waterproof/Fogproof Binoculars, such as Bushnell Marine 7x50MM. 
  • GPS-equipped PDA/handheld computer. We use a Trimble Juno T41 Series Handheld. If this is out of your budget, you can use a handheld GPS to calculate the length of your transects.
  • For backup, we print data forms on Rite in the Rain All-Weather Copier Paper.
  • We put our data forms and protocols in a clipboard Storage Box, such as Officemate OIC Carry-All. 
  • Waterproof Notebook, such as Rite in the Rain All-Weather.

For your convenience, we’ve created a Wishlist on Amazon.com.

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