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101.
Francis Strobbe Mark A. McPeek Marjan De Block Robby Stoks 《Behavioral ecology and sociobiology》2011,65(2):241-247
Despite the importance of foraging activity for the growth/predation risk trade-off, studies that demonstrated predator-induced
survival selection on foraging activity under semi-natural conditions are relatively rare. Here, we tested for fish-induced
selection for reduced foraging activity in two larval Enallagma damselflies using a field enclosure experiment. Fish imposed considerable mortality in both damselfly species and survival
selection on foraging activity could be detected in Enallagma geminatum. We did not detect selection in Enallagma hageni, probably because this species already was not eating very much in the absence of fish compared to E. geminatum. Both species responded strongly to the presence of predators by reducing their foraging activity. The documented survival
selection on foraging activity was detected despite the already low activity levels in fish lake prey species and despite
strong predator-induced plasticity in this trait. 相似文献
102.
Francesca Romana Grati Denise Molina Gomes Jose Carlos Pinto B. Ferreira Celine Dupont Viola Alesi Laetitia Gouas Nina Horelli-Kuitunen Kwong Wai Choy Sandra García-Herrero Alberto Gonzalez de la Vega Krzysztof Piotrowski Rita Genesio Gloria Queipo Barbara Malvestiti Bérénice Hervé Brigitte Benzacken Antonio Novelli Philippe Vago Kirsi Piippo Tak Yeung Leung Federico Maggi Thibault Quibel Anne Claude Tabet Giuseppe Simoni François Vialard 《黑龙江环境通报》2015,35(8):801-809
103.
Sixty-eight yellowfin tuna, Thunnus albacares, (60-135 cm fork length) were caught and released with implanted archival tags offshore off Baja California, Mexico, during
October 2002 and October 2003. Thirty-six fish (53%) were recaptured and the data were downloaded from all 36 recovered tags.
Time at liberty ranged from 9 to 1,161 days, and the data were analyzed for the 20 fish that were at liberty for 154 or more
days. The accuracy in the position estimates, derived from light-level longitude data and sea-surface temperatures (SSTs)
based latitude, is about 0.41° in longitude and 0.82° in latitude, in this region. The movement paths, derived from position
estimates, for the 20 yellowfin indicated that 19 (95%) remained within 1,445 km of their release locations. The estimated
mean velocity along movement paths was 77 km/day. The southern and northern seasonal movement paths observed for yellowfin
off Baja California are influenced by the seasonal movements of the 18°C SST isotherm. Cyclical movements to and from suitable
spawning habitat (≥24°C SST) was observed only for mature fish. For the 12 fish that demonstrated site fidelity, the mean
95 and 50% utilization distributions were 258,730 km2 and 41,260 km2, respectively. Evaluations of the timed depth records resulted in discrimination of four distinct behaviors. When exhibiting
type-1 diving behavior (78.1% of all days at liberty) the fish remained at depths less than 50 m at night and did not dive
to depths greater than about 100 m during the day. Type-2 diving behavior (21.2% of all days at liberty) was characterized
by ten or more dives in excess of 150 m during the day. Type-2 diving behavior is apparently a foraging strategy for fish
targeting prey organisms of the deep-scattering layer during the day, following nighttime foraging within the mixed layer
on the same prey. Yellowfin tuna exhibited occasional deep-diving behavior, and some dives exceeded 1,000 m, where ambient
temperatures were less than 5°C. Surface-oriented behavior, defined as the time fish remained at depths less than 10 m for
more than 10 min, were evaluated. The mean number and duration of surface-oriented events per day for all fish was 14.3 and
28.5 min, respectively. Habitat utilization of yellowfin, presented as monthly composite horizontal and vertical distributions,
indicates confined geographical distributions, apparently resulting from an affinity to an area of high prey availability.
The vertical distributions indicate greater daytime depths in relation to a seasonally deeper mixed layer and a greater proportion
of daytime at shallower depths in relation to a seasonally shallower mixed layer. 相似文献
104.
105.
Joan Solé Albert Sans Magí Riba Gloria Rosell Esmeralda Rosa Lourdes Muñoz Maria Pilar Bosch Angel Guerrero 《Chemoecology》2008,18(2):99-108
Summary. The differing antagonist activity of (Z)-13-hexadecen-2-one (Z11 – 14 :MK, 1) and its 1,1,1-trifluoro derivative (Z11 –14 :TFMK, 2), two closely related analogues of the European corn borer pheromone Ostrinia nubilalis (Z strain), and their rationale is reported. Both chemicals exhibited some electrophysiological activity, and topical application
of 10 pg of pheromone analogue on male antennae was sufficient to induce significantly lower depolarization responses to the
pheromone versus untreated insects. In a wind tunnel, the number of European corn borer males attracted to sources containing
mixtures of 1 + pheromone in ratios ≥ 1 :1 was significantly lower than the number attracted to a source containing pheromone alone. Source
contact behaviour was dramatically impaired when the 1 + pheromone blend reached a ratio of 10 :1, in which only 2% of males displayed source contact in the presence of antagonist.
When compound 1 was present at the source, males usually flew upwind with occasional downwind reversals; when compound 2 was present at the lure, males performed wider crosswind reversals, with little progress toward the source. In the field,
traps baited with mixtures of both compounds with the pheromone in ratios of 5 :1 and 10 :1 elicited a significantly decreased
number of male catches. In esterase inhibition assays, compound 2 was a potent inhibitor (IC50 = 70 nM), whereas the non-fluorinated compound 1 was not. The different activity of both compounds is presumed to be due to different mechanisms of action; considerations
for using methyl ketone analogues as new behavioural antagonists of the pheromone are outlined. 相似文献
106.
107.
Ako AA Shimada J Hosono T Kagabu M Ayuk AR Nkeng GE Eyong GE Fouepe Takounjou AL 《Environmental geochemistry and health》2012,34(5):615-639
Groundwater is the only reliable water resource for drinking, domestic, and agricultural purposes for the people living in the Mount Cameroon area. Hydrogeochemical and R-mode factor analysis were used to identify hydrogeochemical processes controlling spring water quality and assess its usability for the above uses. Main water types in the study area are Ca-Mg-HCO(3) and Na-HCO(3). This study reveals that three processes are controlling the spring water quality. CO(2)-driven silicate weathering and reverse cation exchange are the most important processes affecting the hydrochemistry of the spring waters. While tropical oceanic monsoon chloride-rich/sulfate-rich rainwater seems to affect spring water chemistry at low-altitude areas, strong correlations exist between major ions, dissolved silica and the altitude of springs. In general, the spring waters are suitable for drinking and domestic uses. Total hardness (TH) values indicate a general softness of the waters, which is linked to the development of cardiovascular diseases. Based on Na?%, residual sodium carbonate, sodium adsorption ratio, and the USSL classification, the spring waters are considered suitable for irrigation. Though there is wide spread use of chemical fertilizers and intense urban settlements at the lower flanks of the volcano, anthropogenic activities for now seem to have little impact on the spring water quality. 相似文献
108.
Francesco Ferretti Alessia Costa Marcello Corazza Venusta Pietrocini Gloria Cesaretti Sandro Lovari 《Behavioral ecology and sociobiology》2014,68(8):1335-1344
Availability of food resources and individual characteristics can influence foraging behaviour, which can differ between males and females, leading to different patterns of food/habitat selection. In dimorphic species, females are usually more selective in food choice, show greater bite rates and spend more time foraging than males. We evaluated sexual differences in foraging behaviour in Apennine chamois Rupicapra pyrenaica ornata, during the warm season, before the rut. Both sexes selected nutritious vegetation patches and spent a comparable amount of time feeding. However, males had a significantly greater feeding intensity (bite rate) and a lower search effort for feeding (step rate), as well as they spent more time lying down than females. Females selected foraging sites closer to refuge areas than males. In chamois, sexual size dimorphism is seasonal, being negligible in winter–spring, but increasing to 30–40 % in autumn. Our results suggest that males enhance their energy and mass gain by increasing their food intake rate during the warm season, to face the costs of the mating season (November). Conversely, females seem to prioritize a fine-scale selection of vegetation and the protection of offspring. A great food intake rate of males in the warm season could have developed as a behavioural adaptation leading herbivores to the evolutionary transition from year-round monomorphism to permanent dimorphism, through seasonal dimorphism. 相似文献
109.
S. R. Esterby A. H. El-Shaarawi H. O. Block 《Environmental monitoring and assessment》1992,23(1-3):219-242
Water quality monitoring networks are generally multi-purpose, and thus the data generated are expected to provide information on a set of objectives. Two questions that are fundamental to these objectives are the detection of long term trends and of differences between locations. The extent to which these questions can be answered and the types of statistical methods which can be used are considered in a case study of conventional parameters sampled monthly for nine years. Regression and nonparametric methods, which explicitly account for seasonality, are compared for both the determination of change over time and of differences between locations. Changes over time in the form of step changes and differences between locations which depend upon season were found. 相似文献
110.