Showing papers on "Territoriality published in 2000"

A Review of Ecological Determinants of Territoriality Within Vertebrate Species

Abstract: We reviewed papers that compared intraspecific variation in territoriality vs. alternative forms of spatial or behavioral organization with three goals: (1) to discover which ecological variables act as determinants of territorial behavior and how they might act; (2) to extract and evaluate predictions and evidence for determinants of territoriality and (3) to suggest ways for future studies to build upon what the review revealed. Twenty ecological variables have been predicted, correlated with or experimentally demonstrated to relate to territoriality within vertebrate species. These variables include several characteristics of food: quantity, predictability, distribution, quality, renewal rate, type, density and assessibility. Other variables include nonfood resources, population density, habitat features, mates, space, refuges/spawning/home sites, predation pressure, host nests (for brood parasites) and energy availability. We suggest several reasons why food resources are cited most often, in...

Mate locating strategies of the green carpenter bees Xylocopa (Lestis) aeratus and X. (L.) bombylans

Abstract: This paper describes the mate locating strategies of male Australian carpenter bees Xylocopa (Lestis) aeratus Smith and X.(L.) bombylans (F.). Males of X. aeratus display three different mate locating strategies: (1) non-territorial patrolling near nests or flowers; (2) territorial defence of nests that contain unmated females; (3) non-resource territoriality (hill-topping). At the onset of the mating season, non-territorial patrolling and territorial defence of nests were observed in three out of four populations that were studied, while in a fourth population only non-resource territoriality was observed. Later in the mating season both territorial defence of nests and non-resource territoriality were observed in one of the populations. Male X. bombylans have only been observed using the non-resource territoriality. Males of all size classes used the same strategy at any one time, but males that were observed more than once in a territory were significantly larger, suggesting that larger males have greater territory-holding capacity. Upon encountering males, receptive female X. aeratus alternated low zigzag flights through the vegetation with high-velocity flights well above the vegetation, while males followed closely. This behaviour is interpreted as a test of the flight capacity of males, and is indicative of pronounced female choice. The mate locating strategies of the two species are compared with literature data from other xylocopine bees, and factors that might affect the choice of a particular mate locating strategy are briefly discussed.

Sense of Privacy and Territoriality as a Function of Spatial Layout in University Public Spaces

Abstract: The present study was conducted to investigate the effect of spatial layout in a university public space on two socio-spatial phenomena: territoriality and privacy. The study is based on the assumption that different spatial layouts promote different levels of both territoriality and privacy, which are presumed to be interconnected with social interaction within these layouts. The study tested the effect of five types of outdoor spatial layouts which varied in their architectural and landscape elements. The subjects of the study were all university students who used to hang around the outdoor space of the study. The results indicated the following: First, spatial layout influences our sense of territoriality and sense of privacy, and that vertical spatial elements have greater impact than horizontal ones. Second, both territoriality and privacy are influenced by our ability to control interaction with others. Finally, there was a significant positive correlation between territoriality and privacy.

Alternative Life Styles in a Terrestrial Salamander

Abstract: The association between territoriality and mating strategies has become important in understanding complex social structures of vertebrates (Hixon, 1987). The way in which territories are arranged has a large impact on an individual’s access to potential mates, thus territorial arrangements and mating strategies are inherently interrelated. Davies’ (1992) long-term studies of the dunnock (a small European passerine) showed that both males and females are territorial and that the arrangement of these individual territories influences the type of mating strategies employed by the residents (monogamy, polygyny, polyandry, or polygynandry). In general, amphibian mating systems (particularly in anurans) have been viewed as relatively simple (e.g., Duellman, and Trueb. 1986), with males defending territories that contain necessary resources for females (e.g., Howard, 1978) and with females choosing mates (e.g., Gerhardt, 1991). The redback salamander (Plethodon cinereus: Plethodontidae), however, appears to have evolved a more complicated social system in which males and females may cohabit territories as pairs and may allow juveniles to forage within these territories (Jaeger, 1995).

Winter Territoriality and Irruptive Behavior in the Paridae

Abstract: Irruptions are irregular mass movements performed outside the main breeding area of a species (Svardson 1957, Bock and Lepthien 1976). These movements commonly involve juveniles or individuals with poor competitive ability (Smith and Nilsson 1987) and often are attributed to large-scale variation in food supplies or weather conditions that lead to population booms (Bock and Lepthien 1976, Perrins 1979). Irruptions may be produced after years of good food production followed by a successful breeding season (Ulfstrand 1963, Bejer and Rudemo 1987, Hussell 1996). However, anomalous seed-crop production may be interpreted only as the proximate cause for the irruptive behavior of parids (Ulfstrand 1962) and fringillids (Jenni 1987). Large seed crops increase resource availability and may lead to high population densities, which in turn may force some individuals to make long movements (Ulfstrand et al. 1974). However, some related species of parids with similar foraging behavior and habitat selection (e.g. Great Tit [Parus major] and Marsh Tit [P palustris], or Coal Tit [P ater] and Crested Tit [P cristatus]; Cramp and Perrins 1993) show very different responses to variation in food-crop size, resulting in specific irruptive tendencies. Few studies have been conducted on mechanisms of irruptive behavior (but see Bock and Lepthien 1976). In this study, I used comparative methods to examine possible links between winter territoriality and irruptive behavior in parids. Differences in nonbreeding social systems (i.e. degree of winter territoriality) can affect spacing mechanisms of individuals (Matthysen 1990). Therefore, an increase in the degree of winter territoriality likely would reduce the benefits of irruptive behavior. I also assessed the relative importance of annual fecundity in the predicted relationship between winter territoriality and irruptive behavior, because high fecundity favors offspring production and therefore may lead to irruptive episodes. Methods.-I gathered data from the literature on winter territoriality and irruptive tendency for 13 species of parids and the White-breasted Nuthatch (Sitta carolinensis), which I used as an outgroup (see Appendix). Whether a species was considered to be irruptive was based on information in Cramp and Perrins (1993) and Harrap and Quinn (1996). Al-

An Economic Analysis of Transnational Bankruptcies

Abstract: This paper analyzes the effects of the legal rules governing transnational bankruptcies. We compare a regime of territoriality' -- in which assets are adjudicated by the jurisdiction in which they are located at the time of the bankruptcy -- with a regime of universality are adjudicated in a single jurisdiction. Territoriality is shown to generate a distortion in investment patterns that might lead to an inefficient allocation of capital across countries. We also analyze who gains and who loses from territoriality, explain why countries engage in it even though it reduces global welfare, and identify what can be done to achieve universality.

Theory of resource allocation strategy in territorial male tropical reef fishes

Abstract: A mathematical model is proposed to explain energy resource allocation between sperm production and territoriality in male reef fishes (Labridae species) from the point of view of optimization. Labridae species are typically characterized by both TP (terminal phase) and IP (initial phase) males. The former are considered to release a lower amount of sperm but show aggressive territoriality. In the model, TP male reproductive success is considered as depending upon both fertilization probability (depending on sperm density) and the individual's own territorial activities. Between these factors, a trade-off exists by which the fertilization probability can be enhanced only by reducing territoriality. Therefore, the male has to decide how much of the total available energy resource should be allocated to each. The model showed that under high fertilization efficiency the male can achieve high success by spending less of the resource on sperm production and correspondingly more for territoriality. The TP male reproductive success increases with decreasing male density in the habitat. Nevertheless, when intruding males cannot be excluded completely by territorial behavior of the TP male, females prefer high male density. If females can control the number of intruding males to some degree, conflict may arise between the sexes.