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241.
Information on food waste disposal and on recycling methods and recycled amounts is reported. Data were obtained from a mail and phone survey of all licensed food establishments in Hawaii conducted in 2004 and 2005. Of 8253 licensed food establishments, 5033 completed surveys. It was found that relationships exist between food establishment size (measured by the number of meals served per day or the number of employees) and the amount of food an establishment recycled; establishment type and recycling behavior; and establishment type and amount recycled. The amount of food waste recycled in the state of Hawaii was estimated to be 264,000 L/day and annual food waste generation was estimated to be 336,000 tonnes. 相似文献
242.
We present a hitherto unknown prey perception strategy in bats: Myotis nattereri (Vespertilionidae, Chiroptera) is able to perceive prey by echolocation within a few centimeters of echo-cluttering vegetation,
by using frequency-modulated search signals of very large bandwidth (up to 135 kHz). We describe the species’ search behavior
and echolocation repertoire from the field and from experiments in a flight tent. In the field, bats varied signal parameters
in relation to their distance from vegetation and usually flew close to vegetation. In the flight tent, M. nattereri detected and localized prey by echolocation alone as close as 5 cm from vegetation. Apparently, the bats were able to tolerate
some overlap between prey and clutter echoes. Passive prey cues (vision, olfaction, prey-generated sounds) were not used in
prey perception. The bats selected prey by size. The animals performed aerial catches and produced approach sequences typical
for aerial hawking bats, but were able to do so within a few centimeters of the substrate. M. nattereri thus has access to silent, suspended prey very close to vegetation (e.g., spiders, and caterpillars on threads).
Received: 29 September 1999 / Received in revised form: 12 February 2000 / Accepted: 12 February 2000 相似文献
243.
Characteristics that influence male reproductive success on a lek of Lethrinops c.f. parvidens (Teleostei: Cichlidae) 总被引:1,自引:1,他引:0
Sexual selection has long been proposed as a mechanism leading to the diverse cichlid (Teleostei: Cichlidae) fauna of Lake
Malawi, Africa. Many of the shallow-water, sand-dwelling, bower-building cichlid species are particularly well suited for
studies of sexual selection because they participate in leks. Since females in lekking systems appear to acquire only genetic
material from their mates, it has been suggested that leks are ideal systems to study female mate choice. The objectives of
the investigation were to examine Lethrinops c.f. parvidens male bower characteristics (i.e., bower size and location) as well as other male characteristics (i.e., length, gular color,
and duration on the lek) for their influence on male mating success as measured by the number of visits, circles, and eggs
laid by females. These measures are nested in that a visit by a female may or may not lead to circling, and circling by a
female may or may not lead to egg-laying. We found increased bower height and higher numbers of conspecific neighbors (analogous
to shallow-water, near-shore bower positions) to be positively, significantly associated with the number of visits by females.
The only significant correlate with the number of circles was visits, and similarly circles was the only significant correlate
with the number of eggs laid. The R
2 value for the egg-laying regression was quite low (19.8%) compared with visits (54.3%) and circling (78.9%), suggesting that
females may be using additional cues, that we failed to measure, when in close proximity to males or simply that a small proportion
of the females were ready to spawn. Both indirect selection and direct selection pressure due to egg predation may have influenced
female choice on the lek.
Received: 10 April 1999 / Received in revised form: 26 July 1999 / Accepted: 18 September 1999 相似文献
244.
Aggression and resource sharing among foundresses in the social wasp Polistes dominulus: testing transactional theories of conflict 总被引:3,自引:0,他引:3
Tug-of-war models of within-group conflict predict that the frequency of conflict will be positively related to the degree
of reproductive sharing within the group; in contrast, a negative relationship supports transactional models, in which reproductive
payments among group members limit the degree of within-group selfishness. We tested predictions of the tug-of-war and transactional
models by examining cofoundress interactions during the founding (preworker) phase of colony development in 30 naturally nesting
colonies of the paper wasp Polistes dominulus. We found that the mean rate of foundress aggression and the mean probability of food sharing were significantly negatively
associated, which supports the prediction of the transactional, not the tug-of-war model. Further, cofoundress aggression
significantly increased over the founding phase (independently of temperature), while the fraction of aggression initiated
by the dominant (alpha) foundress significantly decreased over this period. We show that both of these results are predicted
by the transactional model of within-group conflict. Interestingly, the alpha’s rate of aggression was significantly positively
temperature dependent, while the beta’s was not. This indicates that the alpha’s aggression level may often be near her physiological
maximum, while the beta’s aggression is limi- ted by other factors, contradicting the prediction of the tug-of-war model.
Moreover, the alpha’s aggression was significantly positively temperature dependent only in the second half of the founding
period, as predicted by the transactional model since this is when there is least reproductive sharing. Finally, our results
indicate that the alpha’s level of aggression depends on the resources controlled by the beta.
Received: 18 January 2000 / Revised: 19 June 2000 / Accepted: 24 June 2000 相似文献
245.
T. Lubjuhn Wolfgang Winkel Jörg Thomas Epplen Jörg Brün 《Behavioral ecology and sociobiology》2000,48(1):12-17
One of the most interesting aspects of the mating system of pied flycatchers is the regular occurrence of polygyny. Here we
present data on the reproductive success of polygynously paired pied flycatcher males compared to monogamous males based on
paternity analyses through DNA fingerprinting. Males paired with two females suffered a higher loss in reproductive output
per female compared to monogamous males due to (1) a greater proportion of unhatched eggs in their broods, (2) greater nestling
mortality and (3) a greater probability of being cuckolded. Nevertheless, the number of fledglings was significantly greater
for polygynous males. Based on the number of nestlings that returned for subsequent breeding seasons, however, the reproductive
success of monogamous and polygynous males did not differ significantly. These data raise the question as to why males attempt
polygyny.
Received: 16 August 1999 / Received in revised form: 15 March 2000 / Accepted: 18 March 2000 相似文献
246.
247.
Assessing the Geographic Representativeness of Genebank Collections: the Case of Bolivian Wild Potatoes 总被引:5,自引:0,他引:5
R. J. Hijmans K. A. Garrett Z. Huamán D. P. Zhang M. Schreuder M. Bonierbale 《Conservation biology》2000,14(6):1755-1765
Abstract: Genebank collection databases can be used for ecogeographical studies under the assumption that the accessions are a geographically unbiased sample. We evaluated the representativeness of a collection of wild potatoes from Bolivia and defined and assessed four types of bias: species, species-area, hotspot, and infrastructure. Species bias is the sampling of some species more often than others. Species-area bias is a sampling that is disproportionate to the total area in which a species is found. Hotspot bias is the disproportionate sampling of areas with high levels of diversity. Infrastructure bias is the disproportionate sampling of areas near roads and towns. Each of these biases is present in the Bolivian wild potato collection. The infrastructure bias was strong: 60% of all wild potato accessions were collected within 2 km of a road, as opposed to 22%, if collections had been made randomly. This analysis can serve as a guide for future collecting trips. It can also provide baseline information for the application of genebank data in studies based on geographic information systems. 相似文献
248.
The reproductive strategies of two gammaridean amphipod species, Gammarus wilkitzkii and Apherusa glacialis, that permanently inhabit the Arctic sea ice were investigated. G. wilkitzkii reaches sexual maturity at an age of 2 years and produces 128 ± 54 eggs fem.−1 yr−1. Mating takes place during fall and winter, and the development of the large eggs (0.60 to 0.80 mm diam.) lasts 6 to 7 months.
The sex ratio of G. wilkitzkii was dominated by males in a proportion of 1.5:1. In vivo studies showed that juveniles are released in batches from the brood
pouches of the females during April and May. A. glacialis reaches sexual maturity at the age of 1 year and produces 555 ± 151 eggs fem.−1 yr−1. The eggs are between 0.18 and 0.23 mm in diameter, and are the smallest known for gammaridean amphipods. Eggs are kept in
packages of two to eight in the brood pouches of females. The sex ratio of A. glacialis was dominated by females in a proportion of 3:1. The high fecundity of both amphipod species, the release of juveniles in
batches over a period of time, a high proportion of females (A. glacialis), and an elongated life-span with multiple spawnings (G. wilkitzkii) are discussed as possible adaptations to the specific and highly variable conditions under Arctic sea ice.
Received: 29 December 1999 / Accepted: 8 March 2000 相似文献
249.
Strontium (Sr) and calcium (Ca) contents in the otoliths of yellow and silver European eels [Anguilla anguilla (L.)] collected from coastal waters of the Baltic Sea and a freshwater lake in Sweden were examined by wavelength dispersive
X-ray spectrometry with an electron microprobe. The mean Sr/Ca ratios from elver check to otolith edge were significantly
higher for the eels from coastal waters (5.39 ± 1.09‰) than for those from the lake (0.71 ± 0.89‰). The evidence indicates
that European eels in the Baltic Sea do not necessarily migrate into freshwater streams during the growth phase.
Received: 30 September 1999 / Accepted: 6 April 2000 相似文献
250.
Population structure and reproductive ecology of the burrowing ghost shrimp Callianassa filholi Milne-Edwards, 1878 were studied in populations along a latitudinal gradient throughout New Zealand during the breeding season.
Size-frequency distributions revealed unimodal populations, with predominantly sexually mature shrimp. All populations showed
an unbiased sex-ratio, and there appeared to be no significant difference in size (carapace length, CL) between sexes. At
the same time, CL and size at maturity differed significantly between populations; however, a general increase in sizes from
north to south was not consistent throughout the latitudinal range studied. The timing of the breeding cycle differed significantly
between populations, and breeding started earlier in southern populations. Number of embryos (fecundity) increased linearly
with female CL at each location, but rates differed significantly between populations. Embryo size was not related to number
of embryos, and the former increased significantly with latitude. With the exception of embryo size, observed differences
in body size/size at maturity and reproductive timing between C. filholi populations are thought to be determined by food availability rather than temperature. Thus, further study is suggested on
these aspects of thalassinid reproductive biology.
Received: 17 June 1999 / Accepted: 8 January 2000 相似文献