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491.
The fiddler crab Uca perplexa has a conspicuous male courtship signal that is directed at females to attract them to the male’s burrow for mating. The signal involves waving the unflexed large claw up and down. To determine whether the spatiotemporal structure of the wave is under selection by female choice, we examined whether females had a preference for any particular features of the wave. Females respond to a waving display by either visiting the male’s burrow entrance or by electing to pass without visiting the burrow. We filmed mate-searching females and the waving males that they visited or passed. We documented the wave structure of these males using frame-by-frame analysis. Males produce a two-part wave with component A preceding component B. Both components have an upstroke, a pause at the apex and a downstroke. The tip of the claw was raised much higher in B than in A. Visited males had a shorter delay between the two wave components than did males that the females passed without visiting. Visited males also produced component B waves that had a slower upstroke than those of passed males. There was a significant correlation between the relative height of the raised claw and the duration of the upstroke of component B. Females were selecting males that raised their major claw to the highest position (two to three times as high as the carapace width). Passed males brought down their major claw earlier and from a lower position than did visited males. The data suggests that wave structure has evolved through female choice. Male display rate and body size were not female choice cues. An earlier study showed that display duration was also not used by females in selecting mates. 相似文献
492.
Patricia A. Tester 《Marine Biology》1985,89(1):45-53
Experimental results indicate that both parental acclimation temperature and egg-incubation temperature have significant effects on the egg-hatching time of Acartia tonsa Dana between 15° and 25°C. Effects of parental acclimation temperature and egg-incubation temperature are additive if the long-term parental acclimation temperature is constant. A. tonsa are sensitive to temperature and changes of temperature during development (in vivo) and after they are laid (in vitro), up to the time of hatching. A temperature change of the parent culture for time periods of 86 h to 8 d is sufficient to change egg-hatching times. The time required for a temperature change to affect egg-hatching times depends on the magnitude and direction of the temperature change. Field collected A. tonsa demonstrate that changes in egg-hatching times occur in the field populations and can be predicted by mean weekly water temperature. 相似文献
493.
J. Haydock Patricia G. Parker Kerry N. Rabenold 《Behavioral ecology and sociobiology》1996,38(1):1-16
We investigated parentage using multilocus DNA fingerprinting for 222 juveniles produced during 99 group-years in the bicolored
wren Campylorhynchus griseus, a cooperatively breeding bird of the Venezuelan savanna. Young adult bicolored wrens (auxiliaries) remain in their natal
territories and substantially enhance the production of young there. We have previously used behavioral indicators of dominance
by a single male/female pair (principals) to infer breeding status, resulting in the commonly applied model of helping in
which current fitness accrues to auxiliaries only indirectly, in proportion to their relatedness to the principals and the
effect of their assistance on breeding success. Our parentage analysis has demonstrated that 8.6% of the juveniles found on
territories were not produced by the principal pair. Parentage of 4.1% of the juveniles was completely outside the social
group; these appear to result from early dispersal of juveniles rather than from brood parasitism, most likely resulting from
breakup of nearby groups. Principal females mated outside of their group (2.3%), or with an auxiliary male (2.3%), in the
remaining cases of parentage outside the principal pair. No matings were detected between close relatives (e.g. mother-son);
matings detected between the principal female and an auxiliary male followed a typical replacement of the principal female
by an unrelated immigrant female. Our finger-printing results indicate that: (1) current fitness benefits accruing to most
auxiliaries do not exceed their likely reproductive success had they dispersed successfully to a breeding position; (2) nearly
all wren mating is monogamous and (3) behavioral dominants (especially females) can monopolize breeding.
Received: 23 September 1994/Accepted after revision: 10 June 1995 相似文献
494.
Patricia Habuda OByrne Jon P Nelson Joseph J Seneca 《Journal of Environmental Economics and Management》1985,12(2):169-178
Two unresolved issues about airport noise-property value studies are addressed. The first issue concerns the comparability of empirical results from aggregate census data vs individual sales values, and the second issue concerns the homogeneity and stability of results from housing price studies over time and across markets. Hedonic price models from two sets of data for a residential area near the Atlanta International Airport are estimated at two points in time 1979–1980 and 1970–1972. The available data yield similar estimates of the noise discount over time, and from the prices of individual house sales vs owner-appraised census block aggregates. 相似文献
495.
496.
497.
Shoufan Fang George Z. Gertner Alan B. Anderson Heidi R. Howard Patricia Sullivan Chris Otto 《Journal of environmental management》2010,91(3):772-780
Vehicle use during military training activities results in soil disturbance and vegetation loss. The capacity of lands to sustain training is a function of the sensitivity of lands to vehicle use and the pattern of land use. The sensitivity of land to vehicle use has been extensively studied. Less well understood are the spatial patterns of vehicle disturbance. Since disturbance from off-road vehicular traffic moving through complex landscapes varies spatially, a spatially explicit nonlinear regression model (disturbance model) was used to predict the pattern of vehicle disturbance across a training facility. An uncertainty analysis of the model predictions assessed the spatial distribution of prediction uncertainty and the contribution of different error sources to that uncertainty.For the most part, this analysis showed that mapping and modeling process errors contributed more than 95% of the total uncertainty of predicted disturbance, while satellite imagery error contributed less than 5% of the uncertainty. When the total uncertainty was larger than a threshold, modeling error contributed 60% to 90% of the prediction uncertainty. Otherwise, mapping error contributed about 10% to 50% of the total uncertainty. These uncertainty sources were further partitioned spatially based on other sources of uncertainties associated with vehicle moment, landscape characterization, satellite imagery, etc. 相似文献
498.
499.
Patricia Brierley Newell 《Journal of environmental psychology》1998,18(4):357-371
As a further step in developing a systems model of privacy, variables involved in the process of achieving a condition of privacy were examined cross-culturally. Subjects were students from Ireland, Senegal and the United States. Striking commonalities were found in the reasons why subjects required privacy, the affect that was associated with a desire for privacy, the definition of privacy as a condition of the person, the duration of the average privacy experience and the change in affect at the completion of the experience which supported the suggestion that privacy has a therapeutic effect. Within culture, variability was associated with age, gender and in the case of Senegal, with income. Between culture, variability was hardly noticeable. The majority of the subjects in each culture believed that not being disturbed was the most important element of privacy and grief, fatigue and need to focus were the main affective sets associated with seeking privacy. It is believed that several universals have been identified which may be used in later research, and that the study supports a systems-based model of privacy. 相似文献
500.
Patricia Miretzky Carolina Muñoz Alejandro Carrillo-Chávez 《Environmental Chemistry Letters》2007,5(3):131-136
The Pb (II) adsorption/desorption mechanism onto a natural sandy loam soil was studied by batch experiments at different pHs
(3.0, 4.5, 6.0), at different ionic strength (0, 0.02 and 0.1 M) and with different electrolytes solutions of NaCl, NaAcO
and NaNO3. Pb was strongly adsorbed onto the soil due to the formation of a mix of inner-sphere and outer-sphere complexes. Experimental
adsorption data fitted Freundlich and Langmuir isotherms. The desorption results with 0.1 M Mg (NO3)2 and 0.1 M NaAcO solutions corroborated the mechanisms proposed. The strong binding of Pb (II) to high affinity sites on soil
minerals seems to be responsible for the extent of hysteresis. The sandy loam soil under study thus constitutes a natural
control for Pb contamination. 相似文献