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Abstract. Numerous studies reveal strong, positive skews in long-term breeding performance among free-living animals, yet few studies explore the mechanisms underlying such variation. We examine the results of a 12-yr study of a population of Western Gulls, Larus occidentalis. Of 112 pairs for which we have either long-term (Ն5 yr) or lifetime reproductive output, 44% bred for only a single year, and an additional 25% bred for only 2-3 yr. A few pairs bred successfully for 6 -12 yr and showed higher average clutch size, hatching success, and fledging success within any single season than did less successful breeders. The principal trait influencing both survival and reproduction was individual diet, which consisted of a mix of human refuse and fish. A strong, positive relationship existed among the amount of fish taken, breeding life-span, and reproductive performance. Birds with short life-spans took little or no fish on an annual basis. Birds with breeding lifespans Ͼ10 yr and high breeding success took Ͼ60% fish. Diet choice was also important for successful recruitment; 90% of banded offspring returning to breed on the colony had parents that had taken predominantly fish. Diets of male, but not female, recruits were correlated with diets of their parents; 90% of male recruits banded as chicks in the colony were successful breeders, in contrast to 10% of other recruits. Despite apparent selective advantages, few recruits take a diet consisting predominantly of fish, which suggests the existence of at least two alternate tactics, i.e., highly risk-prone foraging for fish, or riskaverse foraging for refuse. This suggests that diet choice is passed between generations by means such as learning or cultural transmission from parents to offspring.

Studies of diet choice in carnivorous animals typically concentrate on maximizing rates of energy intake, and rarely emphasize either constraints on choice or alternate currencies. We examined diet choice in a generalist carnivore, the Herring Gull, Larus argentatus, in relation to both nesting habitat and reproductive performance over a 2—yr period. During prelaying and incubation periods 75—80% of Herring Gulls specialized on either intertidal organisms, human refuse, or other seabirds, while only 20—25% had generalized diets. Specific types of specialists tended to nest in particular habitats. Foraging tactics associated with each of three diets were related to time budgets and ecological constraints, i.e., levels of predation or intraspecific competition in specific habitats. Variation in diet choice was also strongly related to individual breeding performance. Intertidal specialists laid eggs earlier, produced larger and heavier clutches, and had higher rates of hatching than generalists and other specialists. This pattern held true over both years of the study even though weather conditions, and food accessibility, differed between years. Despite differences in performance related to laying and hatching, there were no significant differences in fledging rates, either between years or among diets. These results suggest that (a) choice of nesting habitat may constrain diet choice, (b) diet choice may have major effects on breeding performance, and (c) energy may not be the proper currency for examining diet choice in carnivores subject to a variety of constraints.

Contemporary Western attitudes concerning the management of natural resources , treatment of nonhuman animals, and the natural world emerge from traditions derived from Western European philosophy, i.e., they assume that humans are autonomous from, and in control of, the natural world. A different approach is presented by Traditional Ecological Knowledge (TEK) of indigenous peoples of North America. Although spiritually oriented, TEK converges on Western scientific approaches. TEK is based on close observation of nature and natural phenomena; however, it is combined with a concept of community membership that differs from that of Western political and social thought. TEK is strongly tied to specific physical localities; therefore, all aspects of the physical space can be considered part of the community, including animals, plants, and landforms. As a consequence , native worldviews can be considered to be spatially oriented, in contrast to the temporal orientation of Western political and historical thought. TEK also emphasizes the idea that individual plants and animals exist on their own terms. This sense of place and concern for individuals leads to two basic TEK concepts: (1) all things are connected, which is conceptually related to Western community ecology, and (2) all things are related, which changes the emphasis from the human to the ecological community as the focus of theories concerning nature. Connectedness and relatedness are involved in the clan systems of many indigenous peoples, where nonhuman organisms are recognized as relatives whom the humans are obliged to treat with respect and honor. Convergence of TEK and Western science suggests that there may be areas in which TEK can contribute insights, or possibly even new concepts, to Western science. TEK is inherently multidisciplinary in that it links the human and the nonhuman, and is the basis not only for indigenous concepts of nature, but also for concepts of indigenous politics and ethics. This multidisciplinary aspect suggests that TEK may be useful in resolving conflicts involving a variety of stakeholders and interest groups in controversies over natural resource use, animal rights, and conservation. TEK may also have implications for human behavior and obligations toward other forms of life that are often unrecognized, or at least not emphasized, in Western science. We present examples from community and behavioral ecology where a TEK-based approach yielded unexpected and nonintuitive insights into natural phenomena. Understanding of TEK may be useful in helping scientists respond to the changing public perceptions of science, and new cultural pressures in our society. Capitalism and communism are simply the opposite sides of the same eurocentric coin. What the world needs is not a choice between capitalism and communism , between one aspect of eurocentrism or eu-rosupremacism and another. What we need is a genuine alternative to the European tradition as a whole.