摘要:

AbstractGreen frog (Rana clamitans) tadpoles were exposed to 0, 500, 750 and 1,000 μg Pb/L (as lead nitrate) for 6 d (144 h). Previous studies have shown that similar exposure to 750 or 1,000 μg Pb/L produces deficiencies in both acquisition and retention of learned responses in green frog tadpoles. We examined preference/avoidance responses and spontaneous locomotor activity of Pb‐exposed and control tadpoles to plumes of Pb‐polluted water at each concentration in an octagonal fluviarium. Results indicated no significant preference or avoidance of Pb by either control or Pb‐exposed animals, and no significant effects on the amount of locomotor activity. However, there was significantly greater (p<0.05; foldedFtest) variability in locomotor activity for tadpoles exposed to 750 and 1,000 μg Pb/L compared to control animals and to those exposed to 500

ISSN:0730-7268    

DOI:10.1002/etc.5620090111

出版商:Wiley Periodicals, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractBehavioral responses to environmental chemicals take various forms that may influence the hazard associated with chemical exposures in the field. From integrated laboratory‐field studies that addressed the wildlife hazard associated with two chemicals—paraquat and carbofuran—commonly applied in various agricultural practices, the role of behavioral responses to environmental toxicants may be illustrated. For small mammals, and in particular the cricetid and murid rodents, olfactory and gustatory cues are prominent in influencing the perception of environmental chemicals and eliciting direct or indirect responses to chemical cues. In laboratory studies, subacute dietary exposures were evaluated using microtine rodents; feed aversion and toxicant avoidance appeared the most significant behaviors elicited by feed tainted with either paraquat or carbofuran. Feed aversion was associated with delays in the time‐to‐first‐breeding in carbofuran‐exposed females, while a female‐biased sex ratio in offspring of paraquat‐exposed breeding pairs was not uncommon in these laboratory feeding exposures. Preliminary field investigations that estimated population‐level effects (population size and structure), however, suggested that toxicant avoidance, perhaps mediated through responses like feed aversion, may have ameliorated these indirect toxicant effects. While reproductive function and population‐level effects in small mammals were not apparent in these preliminary field studies, the laboratory studies suggested that various subtle responses related to altered reproductive function may become apparent in long‐term field studies, especially if routes of exposure and chemical bioavailability were altered and different chemical formulations and chem

ISSN:0730-7268    

DOI:10.1002/etc.5620090112

出版商:Wiley Periodicals, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractPrevious studies of toxicant effects on fish foraging behavior and predator‐prey interactions have taken a strictly empirical approach. The most common observation of altered feeding behavior was cessation of feeding or reduction in the amount of artificial food consumed. Changes in the number of live prey attacked and captured, latency to feed and capture efficiency have also been documented. Predator‐prey tests have placed major emphasis on toxicant effects on the ability of prey to escape predation. Several different test systems, as well as model ecosystems, have been used. It is difficult to evaluate the sensitivity of these behavioral tests in relation to standard chronic tests. There was no consistency in test design, and few studies provided information on chemical effects on reproduction or growth in conjunction with behavioral effects. These empirical studies have little basis in ecological theory and do not allow development of testable hypotheses a priori to field verification of laboratory results. Few laboratory feeding studies have been verified in the wild. A mechanistic approach to feeding studies using optimal foraging and bioenergetics models may provide sensitive tests of contaminant effects that may be readily verified in the field. Model simulations demonstrate how toxicant effects on components of fishes' predation sequence can modify the size‐frequency distribution of prey in the fishes' diet and how reductions in the amount of food consumed may alter g

ISSN:0730-7268    

DOI:10.1002/etc.5620090113

出版商:Wiley Periodicals, Inc.    

年代:1990

数据来源: WILEY

ISSN:0730-7268    

DOI:10.1002/etc.5620090114

出版商:Wiley Periodicals, Inc.    

年代:1990

数据来源: WILEY