Search results for "Foraging"
showing 10 items of 204 documents
Parabiotic ants: the costs and benefits of symbiosis
2014
1. Mutualisms are important drivers of co-evolution and speciation. However, they typically imply costs for one or both partners. Each partner consequently tries to maximise benefits and minimise costs. Mutualisms can therefore develop towards commensalism or parasitism if one partner fails to provide sufficient benefits. This is particularly likely in diffuse interactions, where multiple species can associate with each other. If costs and benefits of a species vary with the identity of the partner species, this may result in a geographical mosaic of co-evolution. 2. In the present study, inter-specific interactions in two parabiotic associations of ants were studied (Hymenoptera: Formicida…
The wild side of the New Nordic Cuisine
2021
The Edible Country il primo concreto tentativo di avvicinare il grande pubblico alla filosofia del foraging. Lo scopo quello di incoraggiare le persone a mangiare cibi pi sani e di produzione locale e contemporaneamente a conoscere e rispettare la natura, i suoi cicli, le sue risorse ma anche i suoi limiti. L’utilizzo nel cibo selvatico in cucina, che ha da sempre caratterizzato le economie di sussistenza o i momenti di carestia, assume un nuovo importante significato oggi pi che mai in tempi di crisi economiche e sanitarie. un’importante risorsa alimentare a impatto quasi nullo sul pianeta e il suo valore culturale ci insegna a rispettare gli equilibri dei nostri ecosistemi. Conosc…
Attraction of egg-killing parasitoids toward induced plant volatiles in a multi-herbivore context
2015
In response to insect herbivory, plants emit volatile organic compounds which may act as indirect plant defenses by attracting natural enemies of the attacking herbivore. In nature, plants are often attacked by multiple herbivores, but the majority of studies which have investigated indirect plant defenses to date have focused on the recruitment of different parasitoid species in a single-herbivore context. Here, we report our investigation on the attraction of egg parasitoids of lepidopteran hosts (Trichogramma brassicae and T. evanescens) toward plant volatiles induced by different insect herbivores in olfactometer bioassays. We used a system consisting of a native crucifer, Brassica nigr…
Social information use by predators : expanding the information ecology of prey defences
2022
Social information use is well documented across the animal kingdom, but how it influences ecological and evolutionary processes is only just beginning to be investigated. Here we evaluate how social transmission may influence species interactions and potentially change or create novel selection pressures by focusing on predator-prey interactions, one of the best studied examples of species coevolution. There is extensive research into how prey can use social information to avoid predators, but little synthesis of how social transmission among predators can influence the outcome of different stages of predation. Here we review evidence that predators use social information during 1) encount…
Age-dependent responses to alarm calls depend on foraging activity in Willow TitsPoecile montanus
2011
Survivorship in animals depends on both foraging activities and avoidance of predation, and thus behavioural decisions often reflect a trade-off between predation risk and foraging efficiency. In this experimental study, we compared behavioural responses of free-living adult and juvenile Willow Tits Poecile montanus to a conspecific alarm call in two treatments. The alarm call was played back when a focal bird was either not feeding, or feeding on a sunflower seed on the middle part of a spruce branch. When feeding at the time of the alarm call, juveniles more often stayed motionless or moved shorter distances than adults. Our results suggest that in hierarchical groups, juveniles are force…
Evolution of foraging ecology in Fennoscandian tits ( Parus spp.)
1994
Species belonging to the same genus exploit similar resources in a similar manner. Despite their general similarities in behaviour, they differ in morphology, and these differences are often interpreted as adaptations for use of different resources. Here we report on the relation between morphology, habitat selection and feeding ecology in seven tit species (Parus spp.) in Fennoscandia. A problem previously disregarded in most ecomorphological studies is that members of a guild with closely related species share their common ancestry. This historical legacy causes similarity in ecology and morphology. We have used phylogenetic information with proper comparative methods to reveal the evolut…
Adaptive plasticity of blue tits(Parus caeruleus)and great tits(Parus major)breeding in natural and semi‐natural insular habitats
2004
The breeding performance and foraging of blue and great tits, and the abundance of arthropods living on the trees of an oak-wood and of a coniferous reafforestation were studied in Sicily, in order to: 1) compare breeding parameters in natural and semi-natural habitats within the same area; 2) estimate the degree of overlap in peak resource and peak demand of young tits, and the overlap of nestling diet of the two species in the two habitats. Both species had earlier laying dates, laid more eggs and raised more fledglings in the oakwood than in the reafforestation; they achieved the same fledging success within the same habitat type. These differences are probably due to the earlier and hig…
Learning can be detrimental for a parasitic wasp
2021
Animals have evolved the capacity to learn, and the conventional view is that learning allows individuals to improve foraging decisions. The parasitoid Telenomus podisi has been shown to parasitize eggs of the exotic stink bug Halyomorpha halys at the same rate as eggs of its coevolved host, Podisus maculiventris, but the parasitoid cannot complete its development in the exotic species. We hypothesized that T. podisi learns to exploit cues from this non-coevolved species, thereby increasing unsuccessful parasitism rates. We conducted bioassays to compare the responses of naïve vs. experienced parasitoids on chemical footprints left by one of the two host species. Both naïve and experienced …
Bee reverse-learning behavior and intra-colony differences: Simulations based on behavioral experiments reveal benefits of diversity
2014
Abstract Foraging bees use color cues to help identify rewarding from unrewarding flowers. As environmental conditions change, bees may require behavioral flexibility to reverse their learnt preferences. Learning to discriminate perceptually similar colors takes bees a long time, and thus potentially poses a difficult task to reverse-learn. We trained free-flying honeybees to learn a fine color discrimination task that could only be resolved (with about 70% accuracy) following extended differential conditioning. The bees were then tested for their ability to reverse-learn this visual problem. Subsequent analyses potentially identified individual behavioral differences that could be broadly …
Nest aggregation and reproductive synchrony promote Lesser Kestrel Falco naumanni seasonal fitness
2013
Several factors promote coloniality by enhancing the fitness of colony members. In birds, spatial proximity among nests, breeder abundance and reproductive synchrony have been proposed as primary factors responsible for enhanced colonial defence and foraging success, which, in turn, enhance reproductive success. Whether these factors function synergistically or antagonistically remains, however, an open question due to the absence of an integrated analysis of their effects on fitness. We studied a large population of the Lesser Kestrel, Falco naumanni, a facultative colonial species, breeding in colonies of different sizes in their typical pseudo-steppe habitat. We quantified both the singu…