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121.
122.
Extra-pair paternity and the opportunity for sexual selection in a socially monogamous bird (Dendroica petechia) 总被引:7,自引:0,他引:7
Stephen M. Yezerinac Patrick J. Weatherhead Peter T. Boag 《Behavioral ecology and sociobiology》1995,37(3):179-188
We used multi-locus DNA fingerprinting to characterise the genetic mating system of the socially monogamous yellow warbler (Dendroica petechia). Over 2 years there were no instances of brood parasitism, but 59% of families (n = 90) contained extrapair sired young and 37% of offspring (n = 355) were of extra-pair paternity. Most hypotheses for extra-pair mating in monogamous species assume a paternity benefit to extra-pair sires, and focus on the benefit(s) to females. However, the assumption of male benefit has been little tested. Among yellow warblers, known extra-pair sires were just as likely to be cuckolded as any male in the population, and there was at least one reciprocal exchange of extra-pair paternity. Nevertheless, among known extra-pair sires, the paternity gains from extra-pair paternity were, on average, greater than the losses in their own families. These results show there is a paternity benefit to certain males. However, the benefit is not absolute but relative and therefore more difficult to measure. The results also suggest that patterns of extra-pair fertilisation are not determined by female choice alone. Most confirmed extra-pair mates were territorial neighbours, but some resided as far as three territories apart, and greater spatial separation was implied in other cases. Thus, the opportunity for extra-pair mating is great. We estimate that as a result of extra-pair fertilisations, variance in male mating success is increased somewhere between 3-fold and 15-fold over that which would result from within-pair reproduction alone. These findings affirm the potential importance of extra-pair reproduction for sexual selection in monogamous species and they support earlier suggestions that extra-territorial forays by male yellow warblers are for the purpose of extra-pair mating. 相似文献
123.
124.
András Bardossy Arne Färber Steffen Schönau Bernhard Westrich Thomas Jancke Gerhard Schmid Sven Wurms Karl Stahr Thomas Gaiser Harald Frauenknecht Thilo Streck Joachim Ingwersen Claudia Kreschnak Ulrich Kern Hilke Heppelmann Ekkehard Christoffels Ulrich Förstner Patrick Jacobs 《Environmental Sciences Europe》2006,18(1):67-69
125.
American robin nestlings compete by jockeying for position 总被引:9,自引:0,他引:9
Susan B. McRae Patrick J. Weatherhead Robert Montgomerie 《Behavioral ecology and sociobiology》1993,33(2):101-106
Summary We investigated whether nestling American robins (Turdus migratorius) were capable of influencing food distribution in their nests by perceiving that certain sectors of the nest received a relatively high proportion of feedings and positioning themselves accordingly. Feeding observations were obtained from videotape recordings taken at different stages of the nestling period. Parents generally arrived at a predictable location on the nest rim and allocated proportionally more food to nestlings in the central position. The degree of nestling movement was significantly positively correlated with variation in the predictability of parental arrival locations on the nest rim. Furthermore, nestlings moved more in broods suffering brood reduction. This suggests that when competition for food is intense and the location of parental arrival is predictable, nestlings respond by jockeying for access to the most favorable (i.e., central) position in the nest. We conclude that jockeying for position by nestlings can influence the pattern of food allocation by parents, and that hungry nestlings can improve their competitive standing against nestmates by moving to positions where parents are more likely to feed them.
Correspondence to: S.B. McRae 相似文献
126.
127.
Patrick Gautier Kurtulus Olgun Nazan Uzum Claude Miaud 《Behavioral ecology and sociobiology》2006,59(6):836-841
Gregarious behaviour (i.e. living in groups in contrast to a solitary life) is commonly observed in mammals, but rarely documented
in amphibians. Environmental features and/or animal mutual attractions can promote the formation of aggregations that may
both reduce the risks of dehydration and predation and increase mate access and fitness. Luschan’s salamander (Mertensiella luschani) lives in permanently arid Mediterranean environments; individuals shelter in cracks and crevices and leave only during favourable
periods. In this study we examined the role of chemical tracks, in self and conspecific recognition (i.e. gregarious/solitary
behaviour), on the social structure of this species. Our results show that juveniles and adults of both sexes use chemical
scents deposited on substrate to relocate their shelter. In contrast to numerous other salamander species, Luschan’s salamanders
also use social information, conveyed by conspecific scents, to identify a safe shelter. Furthermore, this scent marking does
not play a role in sexual attraction but allows sex discrimination. This species exhibits gregarious behaviour (i.e. conspecific
attraction) as a possible adaptation to dry environments. We discuss both ultimate and proximate factors in the evolution
from a solitary to a gregarious life. 相似文献
128.
Intertidal mudflats are important nursery grounds for juveniles of many fish species. However, they are being used increasingly to farm bivalve molluscs, which produce large amounts of organic “fluff”, overlying the mud. Fish such as sole, Solea solea, hide in this fluff from potential predators, but the energy consumed by respiring the fluff may be high due to its biorheological properties. We developed an ichthyoviscometer. It incorporates a freshly killed fish as a viscometer, and we developed it to measure the rheological properties of fluids and suspensions, including fluff, at scales encompassing those in gill ventilation. We have shown that the rheological behaviour of fluff is close to that of a gel with a yield stress strongly dependent on particulate organic matter concentration ([POM]). This has allowed us to model fluff flow through the gill channels in living sole as a function of fish size and [POM], showing that in a 26-g sole, fluff would halve flow at a [POM] value of 3.2 g l−1, and stop it at 3.4. 相似文献
129.
Rates of oxygen consumption were measured for embryos, larvae and juveniles of the seastar Mediaster aequalis for 76 days post-fertilization. The rate increased from 0.65 nmol O2 ind–1 h–1 at 6 h after fertilization to 2.8 nmol O2 ind–1 h–1 at day 35. Larvae became competent to metamorphose around day 35 post-fertilization and began to decrease their metabolic rate after this time. Metamorphosed juveniles consumed 0.74 nmol O2 ind–1 h–1. Eggs contained 138.6 µg lipid ind–1 and 12.1 µg protein ind–1. Lipid levels decreased in concentration throughout development while protein levels increased slightly. The lipid levels decreased by 88.5 µg from eggs to day 76 larvae, accounting for 3.5 J of energy. Total oxygen consumption to this point was 3.74 µmol O2 ind–1, accounting for 1.84 J. The energetic demand up to day 76 was met completely through the use of lipid reserves. Metamorphosed juveniles expended 0.5 J more than larvae at the same age. Tubes of the polychaete Phyllochaetopterus prolifica were able to induce metamorphosis in M. aequalis larvae and a non-polar extract of these tubes also triggered metamorphosis. Larvae that are delayed to metamorphose can sustain their metabolic rate with lipid reserves for a limited, yet undetermined, period.Communicated by P.W. Sammarco, Chauvin 相似文献
130.
Industry's role in environmental protection is changing and growing. Increasing evidence shows that a corporation's understanding and response to environmental issues and concerns can have strategically important consequences for some kinds of businesses.1 Focusing on concepts of prevention, industry has developed and struggled with a number of environmental approaches, all of which attempt to link the environment with common business practice. Industry has followed and in some cases embraced concepts and approaches like sustainable development, eco-efficiency, green manufacturing, pollution prevention, and extended product responsibility. A particularly timely and promising strategy to reduce the environmental impact of both manufacturing and product use while enhancing business success is the integration of environmental management systems (EMS) with design for the environment (DFE) efforts. A desirable relationship can and should exist between DFE and EMS. This relationship has not been well understood, but is crucial to fulfill the promise of each. In application, the institutionalization of DFE in an organization is difficult and tenuous at best. Some authors suggest that management issues block the implementation of DFE.2 Others say that DFE has not been institutionalized to the extent that pollution prevention has.3 This article suggests that through an explicit connection between an EMS and DFE, DFE can extend the promise of EMS to reduce industry's environmental impact and produce business success, and it can do so in an ongoing way. The authors will show the importance of an EMS/DFE linkage, suggest company types that might benefit from investigating these approaches, and then review a series of DFE tool types. 相似文献