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      Sooted track plates are another method developed by researchers to equalize the probability of detecting an animal's tracks. While more difficult to set up than scent stations, they have the advantage of providing a record of the track that can be carried out of the field for further inspection. Track plates come in a variety of forms to suit different species, but the basic principle is the same: an animal is lured across a board or “plate” covered with soot, chalk, or some other powdery substance, and then a sticky paper (contact paper) catches the soot from the bottom of the foot. The resulting two-dimensional tracks can be incredibly detailed or a blur of black dust; they are also very different from the three-dimensional tracks we see in earth and snow. For that reason, we have provided here a brief guide to common tracks you might catch when you do this in California, which begins after page 30. This resource was compiled from three resources: (1) tracks caught as part of a southern Sierra Nevada carnivore monitoring program managed by Rick Truex, wildlife biologist for Sequoia National Forest, (2) the collection of William J. Zielinski and Ric Schlexer at the Redwood Sciences Laboratory of the U.S. Forest Service Pacific Southwest Research Station, and (3) several private libraries, primarily Mark Elbroch's, but with generous contributions by Preston Taylor, Casey McFarland, and Neal Wight.

      Track plate methodology has been particularly refined for marten and Fisher detection. Herzog et al. (2009) developed a technique to identify individual Fishers from footprints on track plates and thereby found a noninvasive means of gathering capture-recapture data for quantifying population estimates. Slauson, Truex, and Zielinski (2008) determined that total track length (as defined in the accompanying visual) was an effective method to determine the sex of marten tracks collected on track plates in California. In the Sierra Nevada, the cutoff point is 30.75 mm—larger measurements are males, smaller are females. In the northern Humboldt region, martens are smaller, and the cutoff between the genders was 29.70 mm. Slauson and colleagues (2008) also presented a more complex equation to determine the sex of Fishers from their tracks in California: (1.046 × 13 height) + (1.011 × total length) + (0.361 × 13–14 width). Refer to the illustration to see how to measure these variables. The cutoff point for this equation is 62.17; larger numbers are males, and smaller are females.

      Measurements used in determining gender of marten, and one of the measurements needed to determine gender of Fisher tracks as described by Slauson et al. (2008). Note track is not to scale.

      Additional measurements useful in determining gender in Fisher tracks on soot plates. For this animal, we calculated 60.93, or female. As described in Slauson et al. (2008). Track is to scale.

      For additional information on track plates, see Long et al., Noninvasive Survey Methods for Carnivores (2008), Zielinski and Kucera, American Marten, Fisher, Lynx and Wolverine: Survey Methods for their Detection (1996), and Halfpenny et al., Track Plates for Mammals—A How-To Manual and Aid to Footprint Identification (2010).

      Camera Traps

      There has been an abundance of relatively cheap remote cameras flooding the commercial market in recent years. Hunters often use them to monitor trails, so that they know exactly when and where large bucks prowl. Researchers use them to document the presence of numerous species, especially rare and elusive ones.

      Camera traps are a wonderful complement to traditional tracking skills. They provide a visual confirmation to our interpretations, and provide a way to learn more about tracking. If there is a mystery path created by some animal in your backyard, perhaps a well-placed camera trap can teach you what species created it.

      DIGITAL VERSUS FILM The primary disadvantages of digital remote cameras remain shorter battery life and shutter delay, but these are being resolved with each new generation of cameras. The benefits of not needing to pay for film developing, as well as the ability to instantly see photos (and make adjustments as needed), make digital cameras a better choice for most situations.

      SOOTED TRACK PLATES

      PLATE 1 Sooted Tracks : Actual Size

      Slender salamander (Batrachoseps spp.)

      shrew (Sorex spp.)

      Western Harvest Mouse (Reithrodontomys megalotis)

      Western Red-backed Vole (Myodes californicus)

      Pocket mouse (Chaetodipus and Perognathus spp.)

      Deer mouse (Peromyscus spp.)

      California Vole (Microtus californicus)

      Rough-skinned Newt (Taricha granulosa)

      California Newt (Taricha torosa)

      PLATE 2 Sooted Tracks : Actual Size

      Lizard (Sceloporus spp.)

      Full set of four

      Jumping mouse (Zapus spp.)

      Ermine (Short-tailed Weasel) (Mustela erminea)

      Desert kangaroo rat (Dipodomys spp.)

      Chipmunk (Tamias spp.)

      PLATE 3 Sooted Tracks : Actual Size

      Northern Flying Squirrel (Glaucomys sabrinus)

      Woodrat (Neotoma spp.)

      California Giant Salamander (Dicamptodon ensatus)

      Golden-mantled Ground Squirrel (Spermophilus lateralis)

      American Mink (Neovison vison)

      PLATE 4 Sooted Tracks

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