Rodent Log

User Guide: Logging Your First Rodent Sighting

Thank you for participating with the EUREKA project! The data you collect here can help guide future research, support sustainable rodent management, and enable data-driven decision-making and policymaking.

There is a long wish list of data we’d love for you to collect and share, but we know your time is money, so the only required data to make a submission is two photos.

You are encouraged however, to submit as much data as possible, including biological specimens, and we are keeping a scoreboard to highlight our power users to track:

  • the most data submitted;
  • rats caught;
  • confirmed Alpha rat catches.

As we think these users have made the greatest, validated impact on managing rodents in California.

Instructions

A. Prerequisites

For Photo Capture .jpeg files are suitable, RAW is even better.

1. For iPhones, the ProRaw setting is ideal. On Pro models, this is enabled by Settings>Camera>Formats>AppleProRaw.

2. Samsung requires the Expert Raw app to be downloaded.

3. Geotagging must be enabled:

  • a. For iPhone enable by Settings>Privacy>Location Services> Camera > While using.
  • b. For Samsung enable by Camera Settings>Location Tags>on.

B. Adding a Log

1. Context Photo * (environment or capture location).

2. Specimen Photo * (close-up of the specimen).

3. Found State *:

If you found the specimen in a trap please select “Trapped”.If the rodent was found outside of a trap please select “Found.

C. Specimen Profile

1. Weight (grams)

Ideally, use a digital scale with a flat surface:

  • wear PPE;
  • Place a clean container on the scale, tare it to zero, then add the rodent;
  • Record weight in grams;
  • Either continue to other measurements or safely dispose of rat.

2. Length (inches)

To be measured from Nose to tail:

  • wear PPE;
  • collect a tape measure, fixed or flexible using cm as the unit of measure;
  • record the body length from the nose to the base of the tail (nose to anus);
  • optional. If possible record the length of the tail in a separate box;
  • (the average body length is around 15-25 cm, and the average tail length is 11-24 cm).

3. Species

  • Norway and roof rats can be difficult to distinguish unless seen side-by-side. The simplest way to differentiate them is by their location: Norway rats typically inhabit ground-level areas, while roof rats are found in elevated spaces.

4. Maturity Stage

  • breeding males “boomers” have prominent testes that extend behind the legs (figure 1);
  • if a clear view of the testicles aren’t available, then examine the head for the shape of the snout. Boomers often have large robust snouts (figure 2).

Figure 1: Red circle highlights testes

Figure 2: Red circle highlights Robust male snout

5. Alpha Rat ID (optional field for male specimens)

  • Testicle size measured from left to right (mm).

D. Sample Inventory

Tail Snips:

Tail snips are straight forward and only require a sharp instrument such as a razor and a small tube such as the microcentrifuge tube pictured (Figure 3). (if you need tubes please reach out to EUREKA at our contact information). The following has been adapted from the University of Kentucky.

  1. Don PPE. Your continued health and safety is the most important aspect of sustainable research.
  2. Cut the tail. Cut a small piece of the distal (end/tip) of the tail (2–5 mm from the tip) and place it directly into the pre-labeled microcentrifuge tube. The label on the tube should contain a number or notation that allows it to be matched to the corresponding picture submitted to the app. A larger sample is not more effective, and minimizing the size helps conserve the sample.
  3. Store the sample. Ideally, for long-term preservation, store the sample in a freezer at -20°C. However, DNA will remain usable even if left out at room temperature.