Search results for "Forage"
showing 10 items of 77 documents
Variation in predation risk and vole feeding behaviour: a field test of the risk allocation hypothesis.
2003
Many prey animals experience temporal variation in the risk of predation and therefore face the problem of allocating their time between antipredator efforts and other activities like feeding and breeding. We investigated time allocation of prey animals that balanced predation risk and feeding opportunities. The predation risk allocation hypothesis predicts that animals should forage more in low- than in high-risk situations and that this difference should increase with an increasing attack ratio (i.e. difference between low- and high-risk situations) and proportion of time spent at high risk. To test these predictions we conducted a field test using bank voles ( Clethrionomys glareolus) as…
Seed germination under osmotic stress across different wild populations of mountain rye (Secale strictum (C.Presl) C.Presl))
2020
The selection of resilient cultivars could help stem the losses in forage production due to a changing climate. Secale strictum is a wild grass with interesting potential as a forage crop. We studied the germination requirements of six wild S. strictum populations, representative of the whole species distribution range in Italy and occurring under different osmotic conditions (0 MPa, −0.8 MPa, −1.0 MPa, −1.2 MPa, −1.4 MPa and −1.6 MPa). Our aim was to find beneficial seed and germination traits for the possible use of this species as a crop. Different accessions of domesticated Secale cereale and ×Triticosecale were used as comparison. Some populations of S. strictum were drought tolerant a…
Predator odor recognition and antipredatory response in fish: does the prey know the predator diel rhythm?
2007
We studied in a laboratory experiment using stream tanks if two percid prey fish, the perch (Perca fluviatilis) and the ruffe (Gymnocephalus cernuus), can recognize and respond to increased predation risk using odors of two piscivores, the pike (Esox lucius) and the burbot (Lota lota). Burbot is night-active most of the year but pike hunts predominantly visually whenever there is enough light. Perch is a common day-active prey of pike and dark-active ruffe that of burbot. We predicted that besides recognizing the predator odors, the prey species would respond more strongly to odors of the predator which share the same activity pattern. Both perch and ruffe clearly responded to both predator…
Can video playback provide social information for foraging blue tits?
2017
Video playback is becoming a common method for manipulating social stimuli in experiments. Parid tits are one of the most commonly studied groups of wild birds. However, it is not yet clear if tits respond to video playback or how their behavioural responses should be measured. Behaviours may also differ depending on what they observe demonstrators encountering. Here we present blue tits (Cyanistes caeruleus) videos of demonstrators discovering palatable or aversive prey (injected with bittertasting Bitrex) from coloured feeding cups. First we quantify variation in demonstrators’ responses to the prey items: aversive prey provoked high rates of beak wiping and head shaking. We then show tha…
Mediterranean forage legumes grown alone or in mixture with annual ryegrass: biomass production, N2 fixation, and indices of intercrop efficiency
2016
Aims: To evaluate the productivity and N2 fixation of a range of Mediterranean forage legume species as well as their ability to be grown in mixture with a forage grass, and to verify whether N transfer occurs from the legume to the non-legume component of the mixtures and, if so, to what extent this process is affected by legume species. Methods: Seven legume species (Hedysarum coronarium L., Medicago scutellata L., Trifolium resupinatum L., Trifolium squarrosum L., Trigonella foenum-graecum L., Vicia sativa L., Vicia villosa Roth) were grown alone or in mixture with annual ryegrass (Lolium multiflorum L.). Biomass and N yields and biological N2 fixation (15N dilution technique) were measu…
Community structure affects trophic ontogeny in a predatory fish.
2016
While most studies have focused on the timing and nature of ontogenetic niche shifts, information is scarce about the effects of community structure on trophic ontogeny of top predators. We investigated how community structure affects ontogenetic niche shifts (i.e., relationships between body length, trophic position, and individual dietary specialization) of a predatory fish, brown trout (Salmo trutta). We used stable isotope and stomach content analyses to test how functional characteristics of lake fish community compositions (competition and prey availability) modulate niche shifts in terms of (i) piscivorous behavior, (ii) trophic position, and (iii) individual dietary specialization. …
Macrophytes shape trophic niche variation among generalist fishes.
2017
Generalist species commonly have a fundamental role in ecosystems as they can integrate spatially distinct habitats and food-web compartments, as well as control the composition, abundance and behavior of organisms at different trophic levels. Generalist populations typically consist of specialized individuals, but the potential for and hence degree of individual niche variation can be largely determined by habitat complexity. We compared individual niche variation within three generalist fishes between two comparable lakes in the Czech Republic differing in macrophyte cover, i.e. macrophyte-rich Milada and macrophyte-poor Most. We tested the hypothesis that large individual niche variation…
Abiotic Stress Tolerance of Coastal Accessions of a Promising Forage Species, Trifolium fragiferum
2021
Crop wild relatives are valuable as a genetic resource to develop new crop cultivars, better adapted to increasing environmental heterogeneity and being able to give high quality yields in a changing climate. The aim of the study was to evaluate the tolerance of different accessions of a crop wild relative, Trifolium fragiferum L., from coastal habitats of the Baltic Sea to three abiotic factors (increased soil moisture, trampling, cutting) in controlled conditions. Seeds from four accessions of T. fragiferum, collected in the wild, were used for experiments, and cv. ‘Palestine’ was used as a reference genotype. Plants were cultivated in asymbiotic conditions of soil culture. Treatments wer…
Effect of lemon leaves on energy and C–N balances, methane emission, and milk performance in Murciano-Granadina dairy goats
2018
[EN] The objective of this experiment was to find out the effect of lemon leaves on energy and C-N balances, methane emission, and milk performance in dairy goats. Lemon leaves were used to replace alfalfa as forage in a diet for Murciano-Granadina goats. Ten Murciano-Granadina dairy goats (44.1 +/- 4.47 kg of BW) in late lactation (185 +/- 7.2 d) were selected in a crossover design experiment, where each goat received 2 treatments in 2 periods. One group was fed a mixed ration with 450 g of pelleted alfalfa per kilogram of DM (ALF diet) and, the other group replaced alfalfa with 450 g of pelleted lemon leaves per kilogram DM (LEM diet). The concentrate was pelleted, being the same for the …
The adaptive value of tandem communication in ants:Insights from an agent-based model
2021
AbstractSocial animals often share information about the location of resources, such as a food source or a new nest-site. One well-studied communication strategy in ants is tandem running, whereby a leader guides a recruit to a resource. Tandem running is considered an example of animal teaching because a leader adjusts her behaviour and invests time to help another ant to learn the location of a resource more efficiently. Tandem running also has costs, such as waiting inside the nest for a leader and a reduced walking speed. Whether and when these costs outweigh the benefits of tandem running is not well understood. We developed an agent-based simulation model to investigate the conditions…