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911.
Recent attempts to integrate function and mechanism have resulted in an appreciation of the relevance of forager psychology
to understanding the functional aspects of foraging behaviour. Conversely, an acknowledgement of the functional diversity
of learning mechanisms has led to greater understanding of the adaptive nature of cognition. In this paper, we present data
from three experiments suggesting that noisy miner birds use different cognitive strategies when searching for foods with
different distributions. When searching for nectar, an immobile, readily depleted resource, birds spontaneously attend to
fine-scale spatial information and use a spatial memory-based strategy that is efficient in a novel context and largely resistant
to disruptions to movement. When searching for invertebrates, a mobile, clumped and cryptic resource, birds employ a strategy
whose efficiency increases with increased task familiarity, is vulnerable to disruptions to their movement and may rely more
on memory for movement rules than memory for location information. Previous reports of adapted cognition have reported performance
differences between species (for example, better spatial cognitive performance in storing versus non-storing birds). Ours
is the first study to demonstrate that differences in cognitive strategy (as opposed to just enhanced performance) occur within
a single species in different foraging contexts. As well as providing an example of how specially adapted cognitive mechanisms
might work, our data further emphasise the importance of jointly considering functional and mechanistic aspects to fully understand
the adaptive complexities of behaviour. 相似文献
912.
Recent studies have revealed the importance of self-consistency in evolutionary models, particularly in the context of male–female
interactions. This has been largely ignored in models of the ancestral divergence of the sexes, i.e., the evolution of anisogamy.
Here, we model the evolution of anisogamy in a Fisher-consistent context, explicitly taking into account the number of interacting
individuals in a typical reproductive group. We reveal an interaction between the number of adult individuals in the local
mating group and the selection pressures responsible for the divergence of the sexes. The same underlying model can produce
anisogamy in two different ways. Gamete competition can lead to anisogamy when it is relatively easy for gametes to find each
other, but when this is more difficult and gamete competition is absent, gamete limitation can provide another route for anisogamy
to evolve. In line with earlier models, organismal complexity favors anisogamy. We argue that the early contributions of Kalmus
and Scudo, largely dismissed as group selectionist, are valid under certain conditions. Linking their work with the contributions
of Parker helps to explain why precisely males keep producing more sperm than can ever lead to offspring: sperm could evolve
to provision zygotes but this brings little profit for the effort required, because sperm would have to be equipped with provisioning
ability before it is known which sperm will make it to the fertilization stage. This insight creates a logical link between
paternal care under uncertain paternity (where again investment is selected against when some investment never brings about
genetic benefits) and gamete size evolution. 相似文献
913.
Across animal taxa, exclusive female offspring care has evolved repeatedly from biparental care, suggesting that the latter
becomes evolutionarily unstable under certain conditions. Both the attributes of a species and the environment it experiences
can help to predict shifts from one particular care mode to another. Nevertheless, factors inducing differences in care strategies
among closely related species, or seasonal variation within species, have been subject to surprisingly little empirical testing.
Here, we report the results of a field-based study that examined both among and within species variation in mate desertion
in five species of closely related Nicaraguan cichlid fish in the genera Amphilophus and Amatitlania. The results show a link between female body size and male involvement in offspring care. Specifically, the larger the species
the less often males were found to provide extended care. Furthermore, we found that solitary females became more common towards
the end of the breeding season. We discuss the implications of this finding in the context of previous theoretical and empirical
contributions regarding the frequency of offspring desertion by males. 相似文献
914.
AIC model selection and multimodel inference in behavioral ecology: some background,observations, and comparisons 总被引:4,自引:0,他引:4
Kenneth P. Burnham David R. Anderson Kathryn P. Huyvaert 《Behavioral ecology and sociobiology》2011,65(1):23-35
We briefly outline the information-theoretic (I-T) approaches to valid inference including a review of some simple methods
for making formal inference from all the hypotheses in the model set (multimodel inference). The I-T approaches can replace
the usual t tests and ANOVA tables that are so inferentially limited, but still commonly used. The I-T methods are easy to compute and
understand and provide formal measures of the strength of evidence for both the null and alternative hypotheses, given the
data. We give an example to highlight the importance of deriving alternative hypotheses and representing these as probability
models. Fifteen technical issues are addressed to clarify various points that have appeared incorrectly in the recent literature.
We offer several remarks regarding the future of empirical science and data analysis under an I-T framework. 相似文献
915.
Claire Suchet Laurent Dormont Bertrand Schatz Martin Giurfa Valérie Simon Christine Raynaud Jérôme Chave 《Behavioral ecology and sociobiology》2011,65(5):1015-1027
Two wild subspecies of snapdragon, Antirrhinum majus, subspecies pseudomajus and striatum, differ in floral color and can be visually discriminated by insect visitors. The extent to which olfactory cues derived
from floral scents contribute to discrimination between snapdragon subspecies is however unknown. We tested whether these
two subspecies differ in floral scent and whether these olfactory differences are used by bumblebees (Bombus terrestris) to discriminate between them. We grew individuals of both subspecies, collected from a total of seven wild populations,
under controlled conditions. We quantified the volatile organic compounds (VOCs) emitted by the flowers using gas-chromatography/mass-spectrometry/flame-ionization-detection.
We studied antennal detection of VOCs by bumblebees, by means of electroantennogram study (EAG). We also performed behavioral
experiments in a Y-maze to determine the innate response of bumblebees to the main floral VOCs emitted by our snapdragon subspecies.
The floral scent of Antirrhinum majus pseudomajus contained three volatile benzenoids absent in the floral scent of Antirrhinum majus striatum. One of them, acetophenone, contributed over 69% of the absolute emissions of A. majus pseudomajus. These benzenoids elicited a significantly higher EAG response compared with other VOCs. In the Y-maze, bumblebees were significantly
less attracted by acetophenone, suggesting an aversive effect of this VOC. Our findings indicate that bumblebees are able
to discriminate between the two Antirrhinum majus subspecies. Differences in flower scent between these subspecies and olfactory bumblebee preferences are discussed in the
light of biochemical constraints on VOCs synthesis and of the role of flower scent in the evolutionary ecology of A. majus. 相似文献
916.
Maria Clara P. Amorim José Miguel Simões Vitor C. Almada Paulo J. Fonseca 《Behavioral ecology and sociobiology》2011,65(4):707-716
Signal attributes should show different degrees of variability depending on the information to be conveyed. Species identity
is usually associated with stereotyped features of a signal, whereas other types of information such as individual quality
and motivation are associated with signal plasticity. Lusitanian toadfish males form aggregations during the breeding season
and emit a tonal advertisement call (the boatwhistle) to attract mates to their nests. We test the hypothesis that the boatwhistle
can convey information both on individual identity and motivation by checking how signal parameters vary with time. We study
how the physical (tide level) and social (calling alone or in a chorus) environments and male calling rate affect this advertisement
signal and how all these external and internal factors (environment, social and male motivation) blend to modulate the Lusitanian
toadfish’s advertisement call. Boatwhistles of each male were very stereotyped in short periods of time (minutes), but intra-male
signal variability greatly increased in a longer time scale (days). Nevertheless, significant differences among males could
still be found even in a long time scale. Pulse period was the acoustic feature that most contributed to discriminate among
males. Tide level and male calling rate modulated boatwhistle characteristics, and there was a differential effect of tide
on call attributes depending on male calling rate. Social acoustic environment only affected calling rate. These results suggest
that inter-individual differences in call characteristics and call plasticity may mediate both male–male assessment and mate
choice. 相似文献
917.
Melanie McClure Melissa Ralph Emma Despland 《Behavioral ecology and sociobiology》2011,65(8):1573-1579
Group living is a common strategy among animals and has arisen independently in over 300 species of Lepidoptera. Yet, activity
synchrony between individuals is necessary to derive the benefits that ensue from an aggregated lifestyle. Which individuals
decide which activities to perform and when to perform them is, therefore, a fundamental question. In some species of social
caterpillars and sawflies, the role of a potential behavioral polyethism between individuals has been suggested, whereby certain
individuals are consistently more likely to initiate and lead a foraging event. However, in these cases, evidence in support
of division of labor is lacking. This study was undertaken to determine if certain individuals of Malacosoma disstria are more likely to be consistent group leaders or if transient leaders could be predicted by the differences in energetic
states between individuals. The results of this study indicate that unfed caterpillars initiate foraging bouts and are more
likely to lead locomotion. There was no size or sex-based bias in those individuals that acted as temporary leaders. Consistent
behavioral differences between individuals, if they exist, are therefore not necessary to explain task allocation and synchronization
during foraging in this species. 相似文献
918.
Cynthia A. Ursino María C. De Mársico Mariela Sued Andrés Farall Juan C. Reboreda 《Behavioral ecology and sociobiology》2011,65(12):2279-2286
Obligate avian brood parasites lay their eggs in nests of other species (hosts), which raise parasitic young. Parasitic nestlings
are likely to influence host’s parental behaviours as they typically beg for food more vigorously than young host for a given
hunger level. However, few studies have tested this idea, with conflicting results. These prior studies were largely limited
to biparental hosts, but little is known about the effect of brood parasitism on parental behaviours in hosts that breed cooperatively.
We followed a multimodel approach to examine the effect of brood parasitism on nest provisioning and helper recruitment in
the baywing (Agelaioides badius), a cooperative breeder parasitised by screaming (Molothrus rufoaxillaris) and shiny (Molothrus bonariensis) cowbirds. Multimodel inference results indicated that feeding visits increased with nestling age, cooperative group size
and number of cowbird nestlings in the brood. Brood size had little influence on feeding visits, which further suggests that
baywings adjusted their provisioning effort in response to cowbird parasitism. In addition, nests parasitised artificially
with shiny cowbird eggs or hatchlings recruited more helpers than unmanipulated nests having only host or screaming cowbird
young. Our results provide novel evidence that brood parasitism and cooperative breeding interact in determining the levels
of nest provisioning. 相似文献
919.
Effects of oceanic and terrestrial sediment suspensions on the behavioral traits activity, colony expansion, and mucus formation
of the gorgonian octocoral Subergorgia suberosa (Pallas, 1766) were studied in the laboratory. Increased sediment concentration significantly changed the logits of activity
indices (as colony expansion) and was correlated with decreased activity. For both sources of sediments, the activity index
decreased as the concentration of sediment increased. The level of decrease was more significance for terrestrial sediments.
The activity index showed no clear time pattern for the control group, but a decrease over time occurred in both sediment
treatment groups. Activity change was linearly correlated with exposure time and concentration of terrestrial and ocean sediments.
The activity indices of polyps were negatively correlated with the formation of mucus sheets (correlation = −0.536, p = 0.048). For both sources of sediments, the frequency of mucus sheet formation (MSF) increased with sediment concentration.
Increases in terrestrial sediment loads resulted in more striking effects. The probability for MSF under different sediment
groups at different concentrations over time was modeled by regressions. Frequency of polyp activity is suggested as a suitable
biomarker to monitor the effects of sedimentation stress. 相似文献
920.
Rosemary E. Golding Donald J. Colgan Guy Nelmes Tina Reutelshöfer 《Marine Biology》2011,158(6):1259-1269
DNA sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene were collected from estuarine snails in the genus
Phallomedusa to examine the effects of estuarine isolation on population structure and gene flow. Three clades were recovered, one corresponding
to Phallomedusa austrina and two others with the morphology of Phallomedusa solida. The haplotype diversity in all three clades indicated recent population expansion. Phallomedusa austrina was restricted to the west of a previous land bridge in the Bass Strait between mainland Australia and Tasmania, and P. solida to its east and to northern Tasmania. Phylogeographic analysis of P. austrina and P. solida shows strong geographic separation of species, but no local genetic structure indicative of regional or estuarine isolation.
The clades of P. solida exhibit substantial genetic divergence and were sympatric across their entire distribution in eastern Tasmania and mainland
Australia. Such a situation, which has not previously been observed in phylogeographic studies of southeast Australia, suggests
that P. solida has had a complex refugial history during periods of environmental challenge. 相似文献