Frank B. Golley

Energy Values of Ecological Materials

Since Lindeman (1942) formulated his concept of trophic dynamics, American ecologists have become increasingly interested in the energy relationships of ecosystems. Even though the application of thermodynamic theory to ecology has progressed rapidly (see Odum 1956, Odum and Pinkerton 1955, Patten 1959, Sobodkin 1960), understanding of the energy dynamics of individual populations has been hampered by incomplete knowledge of the energy content of many plants and animals. In energy flow studies it is often necessary to convert biomass to energy by using caloric equivalents obtained from the literature. However, many workers, reluctant to depend upon equivalents, have made their own energy determinations in the oxygen bomb calorimeter. This paper summarizes my analyses of over 400 wild plants and animals collected from the field and over 200 analyses of other workers. These values were previously listed in a mimeographed publication (Golley 1959). I am indebte(d to a number of persons who have aided these studies. In 1956-57 equipment for caloric analyses in the laboratories of the Department of Foods and Nutrition, Michigan State University, was used through the courtesy of Dr. Evelyn Jones. Later studies were made in the ecological laboratory of Dr. E. P. Odum, Univ. of Ga. and the work was supported by the U. S. Atomic Energy Commission, contract At(07-2)-10. I am grateful to Dr. Odum for his critical comments (luring these investigations. I am also grateful to Drs. lawrence Bliss, Univ. of Illinois; Francesco Trama, Rutgers Univ.; Edward Kuenzler, Woods Hole Oceanographic Institute; Clyde Connell, Valdosta State College, Ga.; and J. D). Ovington, The Nature Conservancy, London for providing unpublished data from their studies.

Bioenergetics of the Southern Harvester Ant, Pogonomyrmex Badius

The bioenergetics of the southern harvester ant were studied on the Savannah River Project, Aiken, South Carolina. Excavation of hills revealed that density of ants ranged from 4,000 to 6,000 per hill. Labeling ants with p32 indicated that only 10% of the ants in a colony were active above ground during any 2-week period (the limit of recognition of the label) * thus, short-term marking recapture estimates based on above-ground individuals greatly underestimate the size of the colony. There were 27 hills per hectare on the study area. The consumption of oxygen of workers at various temperatures was determined in a simple respirometer, and the temperature at which the ants were living in the field was determined during a years observation at mounds. The energy expense of heat production was calculated from the oxygen consumption and activity- temperature records. Total energy flow (heat production plus tissue growth) was highest in summer and lowest in winter. The annual range was from 14 to 48 kgcal/m2/yr. Tissue growth was estimated to amount to only 0.09 kgcal/m2/yr. Energy flow in this species was higher than that of 2 vertebrate granivores studied in the same field, the old-field mouse and the savannah sparrow.

Caloric Value of Wet Tropical Forest Vegetation

Energy values of tropical forest vegetation collected in the Republic of Panama differed significantly depending upon the type of forest and the vegetation part sampled. The pattern of difference was complex, with maximum values varying with the plant part and the forest type. Mangrove generally had higher values than other tropical forests. These observations support the earlier conclusion that tropical vegetation has lower energy values than temperate or alpine vegetation.

Food intake and assimilation by bobcats under laboratory conditions.

Energy balance in the wild bobcat (Lynx rufus) was measured on eight animals trapped in the field and maintained on chicken, rabbit (Sylvilagus floridanus), or deer (Odocoileus virginianus) meat diets for up to 100 days. Food intake was found to be subject to much variation, with physical condition (as indicated by behavior, coat condition, and body weight) being maintained on an intake level of one-half the average intake. Energy consumption averaged 138 kcal/kg/day. Percentages of intake energy were as follows: feces, 9 percent; urine, 8 percent; weight gain, 6 percent; and metabolism, 77 percent. There are implications in these observations to understanding the life history of a carnivore. Carnivorous mammals such as the dog and cat were among the earliest species domesticated by man. In these instances, domestication probably meant selection for hunting ability rather than for growth or production. Until very recently, food was usually not provided these carnivores, but rather they were required to obtain their food through hunting, with irregular sup1 This research was supported by a contract between the University of Georgia and the U. S. Atomic Energy Commission [AT (38-1)-310, Tasks 1 and 2]. This content downloaded from 157.55.39.176 on Sat, 09 Apr 2016 06:36:11 UTC All use subject to http://about.jstor.org/terms ENERGY BALANCE IN BOBCATS Golley et al. 443 plements from the campfire or kitchen. Because of this historical background there has been relatively little interest in the study of the nutritional requirements of carnivores. In contrast, many herbivorous mammals have been domesticated for production or work, and the interaction of nutrition and production in these species has been the subject of intense investigation. Recently this situation has changed, and research on the nutrition of carnivorous mammals, such as the dog, cat, fox (Vulpes fulva), and mink (Mustela vison), has increased, principally because these species are being used in a variety of new ways, including the production of fur, and as subjects for scientific research. Nevertheless, it is still true that almost nothing is known about the nutrition of wild carnivores. This paper reports on the energy utilization of wild bobcats maintained under cage conditions. The study does not constitute a nutritional experiment in the usual sense. Because bobcats are difficult to trap and to handle, observations could be collected only irregularly when both animals and facilities were available. Nevertheless, we feel that the animals (eight) which have been maintained on experimental diets for up to 100 days provide unusual information on the trophic dynamics of this elusive species. Further, the information will contribute to the comparative study of energy requirements of carnivores and will also provide a basis for speculation about the role of this important predator in the natural environment. We are grateful to student assistants Samuel R. Chapman, Earl R. Cunningham, Frederic W. Kinard, Jr., Ronald B. Southerland, and Robert W. Walter, who assisted in these experiments by collecting rabbits for food, trapping experimental animals, handling the animals, or in the chemical analyses. METHODS Bobcats used in the experiments came from Georgia and the AEC Savannah River Project (SRP), South Carolina. Two animals, collected in October, 1960 and 1961, were kept on experiment for 15 or 27 days, during which time they were fed daily the legs, head, heart, liver, gizzard, and intestinal tract of one or more chickens. In November, 1962, four bobcats were penned for a 25-day period. During this period these cats were fed frozen whole cottontail rabbits shot on the SRP. In November, 1963, two bobcats were maintained for approximately 100 days on deer meat. The deer meat was obtained from the fore or hind quarters of road-killed deer and was free of fat and skin. In each instance these diets were made up of foods which are similar to those which this species of cat may capture or eat as carrion in its natural state on the SRP (Kight 1962). Within a week after they had been captured, the bobcats were placed in metabolism cages (2 x 2 x 5 feet) which permitted a small amount of exercise. The cages were located in animal rooms with a room temperature between 16 and 20 C. Except for diet, year, and length of time on the experiment, each animal was treated in the same manner. Animals were usually handled after anesthetization with an automatic projectile syringe gun (Crockford et al. 1958). Animals were fed daily. On the chicken and rabbit diets, food and water were provided ad libitum. On the deer diet, food was provided only in sufficient quantity to maintain constant body weight. The wet weight of food was determined immediately before feeding the animal. Feces and urine were usually collected daily. Feces were dried in an oven at 100 C, weighed, ground in a Wiley mill, and stored for caloric analysis. Urine volumes This content downloaded from 157.55.39.176 on Sat, 09 Apr 2016 06:36:11 UTC All use subject to http://about.jstor.org/terms 444 Journal of Wildlife Management, Vol. 29, No. 3, July 1965 Table 1. Caloric equivalents of food and excretory products determined in a feeding experiment with eight penned wild bobcats. NUMBER DRY WEIGHT OF (KCAL/G) SAMPLES

Number and Variety of Small Mammals on the AEC Savannah River Plant

Small mammal populations were sampled by standard traplines for 12 years on the AEC Savannah River Plant, Aiken, South Carolina. In 86,000 trap nights 12 of 15 potentially trappable species were collected. The variety of species was expressed as species per line and species per number of individuals. The species per number of individuals relationship was used to predict the number of individuals that must be captured to collect the regional species pool of 15 species. The number of individuals required ranged from 360,000 by trapping in only one habitat to 700 by stratified sampling based on the percentage occurrence of each habitat on the total land area. Relative abundance of mammals, as influenced by habitat, year and season, was determined from the trapping data. Peromyscus polionotus and Sigmodon hispidus were the most abundant species. Sigmodon was captured in the greatest variety of habitat at the greatest range in abundance, 0.14 to 16.81 individuals per line. P. polionotus was taken in fewer habitats, but at a relatively constant level of abundance of three mice per line. Broomsedge-vine and lespedeza habitats supported greatest numbers of animals; forest habitats, the least.

A Comparison of Variety and Standing Crop of Vegetation on a One-Year and a Twelve-Year Abandoned Field

Studies of the development of old-field vegetation over 12 years on the AEC Savannah River Plant (SRP), Aiken, South Carolina, USA, showed that an inverse relationship existed between the variety of species and the net production of dry matter of the plant community (ODUM 1960; GOLLEY 1965). After farming was abandoned on the SRP, the annual net production of the natural vegetation during the first year of the old-field sere was about 500 g dry matter/m2/year. In three years production declined to about 300 g/m2/year and stabilized at this level through the seventh year. During these first seven years the community was composed of a collection of plant species dominated by the composites Leptilon canadensis, Haplopappus divaricatus, Gnaphalium purpureum, Heterotheca subaxillaris, and the grass Digitaria sanguinalis. During the forb stage the number of species contributing more than one g/m2/year to net production increased from about 5 to 15. In the eighth year the dominance of the community changed from forbs to grasses. The grass Andropogon virginicus became the most important plant in the community and net production increased to 650 g/m2/year, while the variety of dominant species fell to 8. During the succeeding four years the net production declined to 550 g/m2/year and species variety increased to 14. Since the rate of change within or between seral stages of a community may be influenced by the size of the unvegetated area and the invasion ability of the species growing adjacent to the abandoned field (GOLLEY 1965), the observed inverse oscillation between species variety and net production may not always occur. For instance, in small fields succession may be very rapid, with the

Interactions of landscape ecology, planning and design

Abstract Landscape ecology provides planners and designers with two kinds of information. First, landscape ecology describes the structure of the physical and biological environment at a scale that is practical for humans. Second, landscape ecology describes dynamic processes in time and space, and explores the ways in which structures shape processes. An understanding of processes allows us to extrapolate patterns into the future and, therefore, to plan and to predict the consequences of design. Building a strong connection between landscape ecology, planning and design requires special training and experience. The Institute of Mediterranean Agronomy of Zaragoza, Spain, which is part of the International Center of Higher Studies in Mediterranean Agronomy, Paris, has been teaching courses on rural planning and the environment for over 12 years. This course experience, and the research associated with it, provides an example of how these separate disciplines can be integrated.

Assessing the Environmental Literacy Requirement at the University of Georgia.

The University of Georgia (UGA) is one of the first universities in the United States to require that every undergraduate student complete an environmental literacy requirement (ELR). The ELR has been in place since 1993. Three students examined the ELR through formal and informal studies and surveys. Their results showed that students were enthusiastic about the ELR and that they welcomed increased knowledge about the environment. Faculty thought that the ELR was useful but were dissatisfied with the criteria defining environmental literacy. The studies showed that there was wide interest and acceptance of an ELR but that lack of coordination and leadership has resulted in debate about its role in the institution. Although debate threatens the survival of this special requirement, modest changes in the ELR will likely save it. The experiences of UGA will be of value to other academic institutions contemplating a broad environmental requirement.

Response of Wild Rodents to Acute Gamma Radiation

Recent reports have shown that some species of small wild rodents, pocket mice (Perognathus longimembris and Perognathus formosus) (1) and cotton rats (Sigmodon hispidus) (2), given an acute dose of y-radiation have an LD50o(3o) that ranges between 1200 and 1500 r. This level of lethality is considerably higher than that of the laboratory mouse (544 to 665 r) (3) and the laboratory rat (665 r) (4), animals of approximately the same body size as the pocket mouse and cotton rat. Since it has been suggested that resistance to radiation is a criterion of general fitness (5), it might be concluded that wild rodents that are genetically diverse and as adults have passed through a period of rigorous natural selection are more fit and also more resistant than laboratory rodents. Alternatively, these data may represent exceptional species. Our studies have been designed to obtain evidence on these questions of comparative radiation sensitivity. Since a large number of variables such as age, sex, kind and intensity of radiation, previous treatment, length of time in captivity, genetic background, and environment affect lethality and make comparison of the results from different experiments and laboratories difficult, the procedure in these studies has been to collect adult wild small mammals by live-trapping and to compare their response to acute y-radiation with that of domestic mice under both laboratory and field conditions. Where possible, both wild and domestic forms of the same species have been used. In the laboratory experiments the wild mammals must adjust to the unusually stabile laboratory environment; in the field experiments the domestic mammals must adjust to a constantly fluctuating environment. Thus, the experimental design compares wild and domestic forms within a species and between

Forest reconstruction as ecological engineering

Abstract Land restoration involves reconstruction of the native biota in a sustainable form. If reconstruction involves deliberate manipulation of biological organisms and the physical-chemical environment to achieve specific human goals, it qualifies as ecological engineering. Restoration which uses natural processes to achieve endpoints which are unpredictable but can be accepted because they are “natural” is not ecological engineering. In Japan a system of forest reconstruction has been developed which is based on knowledge of the potential vegetation of a site, knowledge of the methods of germination and growth of the species which compose the mature vegetation and a method of site preparation and planting. This ecological engineering approach has been used on 285 sites, in a variety of habitats, to form dense stands of vegetation to hide industrial complexes, control visual, noise and chemical pollution, stabilize soil and beaches and provide urban green space. The technique has also been used to restore tropical rain forest.