Animal Ecology

Abstract

Aide Leopold, wildlife manager. BackgroundConcentration of studies not on the rare but on the most abundant and influential organisms in the community. Measurement and evaluation of physical factors in the actual microhabitat occupied by organisms. Correlation of findings of experimental studies of organisms in the laboratory with observations of those organisms in the field. Use of quantitative-not just qualitative-techniques in field studies as well as laboratory studies. A study of organisms in the field may bring to light problems which will be most expediently worked out in the laboratory ; but field and laboratory investi-Iictuiin;/ till' beauty oj its on/anicatiou is perhaps better in proportion ( Mac lady en 1957: 246). RKLATION TO OTHER SCIENCESEcology is one of tlie three main divisions of biology : the other two being morphology and physiology. The emphasis in morphology is on understanding the structure of organisms ; in physiology, on how they function : and in ecology, on their adjustments to the environment. These divisions overlap broadly. To appreciate fully the structure of an organ, one needs to know how it functions, and the way it functions is clearly related to environmental conditions. The morphologist is concerned with problems of anatomy, histology, cytologj', embryology, evolution, and genetics : the physiologist, with interpreting functions in terms of chemistry, physics, and mathematics : and the ecologist, with distribution, behavior, populations, and communities. The evolution of adaptation and of species is of mutual interest to the ecologist and to the geneticist ; bioclimatology is a connecting link between ecology and physiology.All areas, in the final analysis, are simply different approaches to an understanding of the meaning of life. SUBDIVISIONS OF ECOLOGYEcology may be studied with particular reference to animals or to plants, hence animal ecology and plant ecology. Animal ecology, however, cannot be adequately understood except against a considerable background of plant ecology. When animals and plants are given equal emphasis, the term bioecology is often used. Courses in plant ecology usually dismiss animals as but one of many factors in the environment. Synecology is the study of communities, and autccology the study of species.In this book we shall survey the fundamentals and basic facts of animal ecology. We will study comnmnity ecology, the local distribution of animals in various habitats, the recognition of community units, and succession ; ecological dynamics, the processes of dispersal, ecesis, reaction, coaction, productivity, competition, speciation, and regulation of abundance ; and geographic ecology, geographic distribution, palaeoecology. and biomes. We will also be interested throughout the text with how species and individuals respond and adjust to the physical factors of their environment, but a full study of physiological ecology must be left to another time and place.When special consideration of their ecology is given to one or another taxonomic group,...

Establishment of Invertebrate Communities on Log Substrates in the Kaskaskia River, Illinois

“…The riffte habitat was relatively severe, allowing only those organisms with fast-water adaptations to exist in large numbers. These adaptations (Kendeigh 1961) include streamlined shape, especially in the plecopterans and hydropsychids, secretion by simuliids of a silken thread by which they attach to the rocky bottom, and the construction of cases by the hydropsychids.…”

Population ecology of swift foxes (Vulpes velox) in southeastern Colorado

“…Elevation varies from 1310 to 1740 m. Topography consists of broad, moderately sloping uplands, limestone hills, and sandstone canyons (U.S. Army 2 ; Gese et al 1988). The vegetation is dominated by shortgrass prairie and woodland communities consisting of pinyon pine (Pinus edulis) and one-seeded juniper (Juniperus monosperma) (Costello 1954;Kendeigh 1961). Grasslands constitute approximately 60% of the vegetative cover (Shaw et al 1989), with blue grama (Bouteloua gracilis), sideoats grama (B. curtipendula), western wheatgrass (Agropyron smithii), galleta (Hilaria jamesii), and needle-and-thread (Stipa comata) predominating.…”

Morphological Changes in Swine Associated with Environmental Temperature

“…Most textbooks of ecology discuss temperature and climatic effects on animals as they relate to Bergmann's or to Allen's Rule (Chapman 1931, Bodenheimer 1938, Allee et a!. 1949Kendeigh 1961, and Knight 1965, but only earlier works give adequate description or definition of these rules. Based on measurements of animals killed in their natural environment, Bergmann (1847) stated that within a given species, mammals and birds increase in size toward the colder portion of the temperature range they occ!:py.…”