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61.
Timothée Romuald Cook Frédéric Bailleul Amélie Lescroël Yann Tremblay Charles-André Bost 《Marine Biology》2008,154(2):383-391
Knowing the depth zone of neutral buoyancy of divers is important because buoyancy can determine how animals manage their
energy budget. In this study, we estimate the depth zone of neutral buoyancy of free-ranging cormorants for the first time,
using time-depth recorders. We discovered that vertical ascent rates of 12 Crozet and 15 Kerguelen diving blue-eyed shags
(respectively Phalacrocorax
melanogenis and P.
verrucosus) slowed down considerably at the 50–60 m depth zone. We suggest this was due to birds trying to reach the surface from that
point upwards using reduced locomotor activity because the force of buoyancy becomes greater than the force of gravity at
that depth. The results show a shift of this depth zone in relation to maximum targeted dive depth, suggesting cormorants
may control buoyancy through respiratory air volume adjustment. Interestingly, 60 m is close to the maximum depth zone reached
by these two species during dives lasting 4 min, their estimated behavioural aerobic dive limit. This suggests that the decision
to swim deeper has a direct consequence on the energy budget, with time spent recovering at the surface (time thus lost to
foraging) strongly increasing relative to the preceding time of submergence. Resources found in deeper waters must be of sufficient
quantity or quality to justify crossing the frontier of physical neutral buoyancy. 相似文献
62.
Deseada Parejo Étienne Danchin Nadia Silva Joel F. White Amélie N. Dreiss Jesús M. Avilés 《Behavioral ecology and sociobiology》2008,62(10):1569-1579
Sympatric species sharing requirements are competitors, but recent evidence suggests that heterospecifics may also be used
as a source of information. The heterospecific habitat copying hypothesis proposes that individuals of one species might use
information inadvertently produced by the breeding performance of individuals of other species to assess habitat quality whenever
the two species share needs. In this study, we provide the first experimental test of this hypothesis by examining whether
the manipulated reproductive success of blue tits (Cyanistes caeruleus) is used as heterospecific inadvertent social information (ISI) in breeding-habitat selection by sympatric great tits (Parus major). The reproductive success of blue tits was manipulated 1year at the scale of patches by transferring nestlings from decreased
to increased patches. No evidence was found of great tits using the reproductive success of blue tits as a source of heterospecific
ISI. However, dispersal decisions by adult great tits correlated with information on con- and heterospecific densities, which
constitute other sources of ISI. As density and breeding performance are tightly intertwined forms of information, the difficulty
in distinguishing between them might lead great tits to use heterospecific ISI more in the form of density than breeding performance
when making dispersal decisions. 相似文献
63.
Amélia Viricel Allan E. Strand Patricia E. Rosel Vincent Ridoux Pascale Garcia 《Behavioral ecology and sociobiology》2008,63(2):173-185
Compared to terrestrial mammals, little is known of cetacean social systems as they are generally less accessible to behavioral
investigations due to their aquatic environment. The present study investigates group structure of the pelagic common dolphin,
Delphinus delphis, using genetic markers. Tissue samples from 52 individuals representing a recent live mass-stranding event were compared
to 42 single strandings taken from presumably different groups. The mass-stranding event occurred in 2002 on the French coast
of the English Channel, whereas the single strandings were collected between 1993 and 2003 along the western coast of France
(Bay of Biscay and English Channel). Analysis of mitochondrial DNA control region sequences indicated that genetic variability
within the mass-stranded pod was similar to variability observed in single strandings. The mass-stranded group was composed
of 41 different mitochondrial haplotypes or matrilines while the single strandings revealed 29 different haplotypes. Analysis
of 11 microsatellite loci revealed that average relatedness of the mass-stranded pod was not different from average relatedness
among all single strandings suggesting that individuals within the group had no closer kin relationships than animals taken
from presumably different groups. These results do not support a matriarchal system and suggest that common dolphins constituting
a pod are not necessarily genetically related. 相似文献
64.
Beig Bilal Niazi Muhammad Bilal Khan Sher Farooq Jahan Zaib Malik Umer Shahzad Khan Mohammad Daud Américo-Pinheiro Juliana Heloisa Pinê Vo Dai-Viet N. 《Environmental Chemistry Letters》2022,20(4):2709-2726
The rising population is increasing food demand, yet actual crop production is limited by the poor efficiency of classical fertilizers. In particular, only about 40–60% of fertilizer nitrogen, 15–20% of phosphorus and 50–60% of potassium are used by crop plants, the rest ending polluting the environment. Nanofertilizers are promising alternatives. Here, we review plant nutrients, synthesis of zinc oxide nanoparticles, encapsulation of nanoparticles in fertilizers, and effect on plants.
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