Field Guide to Animal Tracks and Scat of California. Lawrence Mark Elbroch. Читать онлайн. Newlib. NEWLIB.NET

Автор: Lawrence Mark Elbroch
Издательство: Ingram
Серия: California Natural History Guides
Жанр произведения: Биология
Год издания: 0
isbn: 9780520951648
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skills are real and amazing. Yet they do not come easily, and they require ample time in the field. Consider this example: Stander and colleagues (1997) observed a Zebra dying of anthrax (blood sampling confirmed the cause), and over the next several days a Lion pride, hyenas, and vultures feeding and disassembling the carcass. They brought a team of four Ju/'huan trackers (Bushman in Namibia) to the area three days after the Zebra had died and asked them to reconstruct what had happened. The trackers investigated the area for two hours before coming to an agreement as to what had occurred. Then they correctly pointed out the spoor of the Zebra and said that the animal was sick and had died from that sickness. They correctly identified all the scavengers and the order in which they fed. They also correctly estimated the relative chronology of events, including the death of the Zebra.

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      A page from author Mike Kresky's tracking journal.

      You, too, can achieve this level of tracking, given persistence and practice. We hope this book provides some of the necessary building blocks and so shortens your journey. Now follow Gary Snyder's (1995) advice found at the very start of this chapter, and “go out and explore California!”

      GETTING STARTED

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       Why Tracks and Scats?

       Mark Elbroch

      We were faced with a decision at the start of this project. Given the size parameters of this field guide series, we could either present a detailed look at animals' tracks and scats, or use a more superficial approach to a broader diversity of signs—that is, evidence of feeding, beds, and the like. In the end we decided on the former—an in-depth presentation of just several topics. This book is a visual presentation of the tracks, scats, and scent-marking behaviors of California's wildlife.

      Interpreting wildlife tracks and signs is challenging detective work; it is an engaging exercise in clear thinking and deductive reasoning. The most reliable tools we have at our disposal to solve the natural mysteries we encounter in the field are animal tracks and scats. Tracks and scats are the foundation blocks in interpreting all indirect evidence of wildlife, and a detailed knowledge of tracks and scats will aid you in interpreting nearly every natural mystery you encounter.

      The presentation of this book also includes numerous citations of work completed by others. They may at first seem obstacles to easy reading, but they serve two powerful purposes: First, they are evidence that tracking has forever been integral to wildlife research and monitoring, and second, they are additional resources for you, the readers, to follow up and seek out should a specific topic grab your interest.

      There are without doubt numerous methods to speed you along in your study of wildlife tracking. One of us, Michael Kresky, provides a lively description of one method—track journaling—and through this method he has become an expert interpreter of wildlife tracks and signs. Here he shares tips on this process.

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      Look closely for the California Red-backed Vole remains and the two uric streaks, which are the best evidence that the killer was an American Kestrel.

       Honing Your Tracking Skills through Track Journaling

       Michael Kresky

      Tracking Journal

      Track journaling builds your knowledge of tracks and sign by making you observe tracks in close detail; your journal also becomes data, meaning scientific records, of what you discover. The physical act of drawing tracks and taking notes on your surroundings sharpens your ability to see clearly and with greater discernment. While you hover over a set of prints, patterns and shapes begin to emerge. We realize that journaling can be intimidating at first, but keep in mind that each journal is highly personal and evolves over time. Nature Drawing—A Tool for Learning, by Clare Walker Leslie (1995), can guide you in this process.

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      Author Mike Kresky journals a set of raccoon tracks under a bridge in Santa Barbara, California.

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      Tracker Louis Liebenberg taking measurements to create an accurate, life-sized rendition of wolf tracks in central Idaho.

      When drawing tracks, do not be daunted by the unknown. Often scrutinizing prints and investigating details with poignant questions will lead to tracks revealing themselves. Even when they do not, it is still valuable to draw the track and revisit your journal at later times.

      In the field you need a sketchbook or clipboard, pencils or markers, and a measuring device (ruler or calipers). Begin by finding four to six clear prints that you believe belong to the same animal, and choose a single track to draw. Make sure that the track is between you and the light source. Treat the track and the area around the tracks with deference. This preserves the features of the track as well as the story around the tracks.

      An effective track journal includes the date, time, weather, habitat, substrate, and wildlife and human activity in the surrounding area. Draw the track, showing the features of the toes and heel pad or claw marks. With a measuring device, note the track's length and width. The most important thing to remember is to be consistent in your practice. For example, when measuring a track, always include the claws in your measurements. In addition, record whether the track is from a front or hind foot, which side of body, and the direction in which the animal was traveling.

      Many folks new to sketching in general are unsure how to use shading to convey light or depth. The choice is ultimately up to you. First, try using shading to relay light—how the sun is falling over and/or across the footprint. Second, use shading to relay depth, meaning that you would shade the deepest parts of the footprint the darkest and the shallowest portions the lightest. We would, however, recommend the second method, because shadows created by light sources can distort one's perception of tracks, as we discuss under notes on photography.

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      An excerpt from Mike Kresky's journals.

      Once you have finished drawing the track, step away from it. This gives you a broader perspective, allowing you to see the line of tracks and perhaps discern the gait the animal was using. This perspective offers more information about the interpretation of this animal's behavior. You may notice that the animal was walking, dust bathing, or foraging. After you have drawn an individual track, draw the line of tracks. Measure the distance between the footfalls, again making sure that you are consistent. Although track journaling is a highly focused activity, remind yourself to pay attention to bird song and other animal behaviors. You may be surprised to find that you are near to the animal you are journaling.

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      Here Mike Kresky has drawn an area map to accompany his journals of individual tracks and trails.

      Maps in Your Track Journaling

      It is essential to be familiar with the topography where you track. Topographical maps teach us the salient features of the landscape. Specific maps, such as geological, hydrological, or vegetative, provide different perspectives on the natural history of an area. An awareness of topographical information and patterns in your immediate landscape is invaluable for locating ecotones, corridors, and the animals themselves.

      In addition to referencing published maps, create your own maps to hone your tracking skills. Start with a map with a one- or two-mile diameter. Then create a map that covers only several hundred feet. Center this map around your set of tracks. Once the tracks have been drawn, fill in the rest of the map