It is difficult to capture arboreal mammals because of the logistical complications in working in the canopy. As with subterranean mammals, if arboreal species have a period of the day or year that they use the ground or come close to the ground, they can most readily be sampled at that time. Sometimes species can be anesthetized with drugs delivered in a dart, but still there is the problem of the animal falling from the canopy when the drug takes affect. Diurnal species can be surveyed with distance sampling, or mark/recapture techniques when there are unique markings. Nocturnal species are more difficult to survey visually because the darkness increases their cryptic ability and there is difficulty in estimating distance; indexes can be derived from calls and visual detections along transects. For nocturnal species, use of a spotlight to detect "eye-shine" makes transect surveys feasible. Many species do have unique calls that can be used for index surveys. Radio telemetry can be used if the animal can be captured. For animals that forage high in the canopy, the utility of radio telemetry is diminished because it is difficult to estimate the third dimension in an animal's space use.
Clearly, one technique cannot be used to study all mammals. A study that attempts to record the density and behavior of all mammal species within an area has a daunting task that will take time and money to accomplish. A population study for a single species or suite of species must be tailored to match the habits and attributes of the animal. An advantage to mammal studies is that there is a rich literature of mammal field research conducted over the past 100 years that can provide guidelines. With increasing human densities, the affairs of mammals and humans can no longer be separated, and understanding wild mammals is the first step to ensuring their survival.
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This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.