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211.
Signe Brinkløv Elisabeth K. V. Kalko Annemarie Surlykke 《Behavioral ecology and sociobiology》2010,64(11):1867-1874
Echolocating bats adjust the time–frequency structure such as sweep rate and pulse interval of their sonar calls when they
move from open space to vegetation-dense environments. Emitted call intensity is equally important for echolocation, but adjustment
of signal intensity to different habitats has never been systematically studied in any bat species. To address this question,
we recorded sonar calls of the Neotropical trawling insectivorous bat Macrophyllum macrophyllum (Phyllostomidae) at three sites with different obstacle densities (clutter). We found a clear correlation between emitted
intensity and degree of clutter, with intensity proportional to decreasing clutter. In highly cluttered, semicluttered, and
open spaces, M. macrophyllum emitted calls with mean source levels (sound pressure level (SPL) 10 cm from the bat’s mouth) of 100, 105, and 111 dB SPL
root mean square (rms), respectively. To our knowledge, this is the first documentation of dynamic intensity adjustments in
bats. Phyllostomid bats were previously considered silent, but the 111-dB SPL rms emitted by free-ranging M. macrophyllum in open space is comparable to output in aerial insectivorous bats from other families. Our results suggest that the acoustic
constraints of habitats are better predictors of call intensity than phylogeny and therefore likely to be major drivers shaping
the sonar system of bats in the course of evolution. 相似文献
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Antoon Opperhulzen Els W. v. d. Volde Frank A. P. C. Gobas Djlen A. K. Liem Jan M. D. v. d. Steen 《Chemosphere》1985,14(11-12)
Most polychlorinated naphthalones (PCN) accumulate rapidly according to their hydrophobicity. The uptake and ellmination rate constants are comparable to those of chlorinated benzenes and biphenyls.For most PCN-congeners the resulting bioaccumulation factors show an increase with increasing hydrophobicity. For higher Kd,oct-values (>105) however, no further increase of Kc is observed (Kc. max. = 3.5.104).For the two hepta- and the octachloronaphthalenes no detectable concentrations are found in the fishes, although no restricted blo-availability could be expected. Based on these observations and on data obtained from the literature. a loss of membrane permeation is suggested for hydrophobic molecules with widths over 9.5 Å.In addition a membrane permeation model, as part of the accumulation process of hydrophobic chemicals. Is proposed, which is based on diffusion and partition processes. 相似文献
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