scholarly journals Mere presence of co-eater automatically shifts foraging tactics toward ‘Fast and Easy' food in humans

2020 ◽  
Vol 7 (4) ◽  
pp. 200044
Author(s):  
Yukiko Ogura ◽  
Taku Masamoto ◽  
Tatsuya Kameda
Keyword(s):  
Foraging Behaviour ◽  
Eating Behaviour ◽  
Food Competition ◽  
The Other ◽  
Social Foraging ◽  
Social Animals ◽  
Mere Presence ◽  
Foraging Tactics ◽  
Competition For Food ◽  
Potential Food

Competition for food resources is widespread in nature. The foraging behaviour of social animals should thus be adapted to potential food competition. We conjectured that in the presence of co-foragers, animals would shift their tactics to forage more frequently for smaller food. Because smaller foods are more abundant in nature and allow faster consumption, such tactics should allow animals to consume food more securely against scrounging. We experimentally tested whether such a shift would be triggered automatically in human eating behaviour, even when there was no rivalry about food consumption. To prevent subjects from having rivalry, they were instructed to engage in a ‘taste test' in a laboratory, alone or in pairs. Even though the other subject was merely present and there was no real competition for food, subjects in pairs immediately exhibited a systematic behavioural shift to reaching for smaller food amounts more frequently, which was clearly distinct from their reaching patterns both when eating alone and when simply weighing the same food without eating any. These patterns suggest that behavioural shifts in the presence of others may be built-in tactics in humans (and possibly in other gregarious animals as well) to adapt to potential food competition in social foraging.

The influence of wing morphology and echolocation on the gleaning ability of the insectivorous bat Myotis tricolor

2004 ◽  
Vol 82 (12) ◽  
pp. 1854-1863 ◽  
Author(s):  
Samantha Stoffberg ◽  
David S Jacobs
Keyword(s):  
Discriminant Analysis ◽  
Foraging Behaviour ◽  
Myotis Lucifugus ◽  
The Other ◽  
Wing Morphology ◽  
Echolocation Calls ◽  
Narrow Bandwidth ◽  
Mole Crickets ◽  
Wing Tips ◽  
Wing Tip

On the basis of its external morphology, Myotis tricolor (Temminck, 1832) should be able to both aerial-feed and glean. Furthermore, this bat is known to use broadband calls of short duration, reinforcing the prediction that it gleans. However, results from this study indicate that M. tricolor does not commonly glean. This conclusion was reached after studying the foraging behaviour of M. tricolor in a flight room. We presented M. tricolor with mealworms, moths, mole crickets, beetles, and cicadas in a variety of ways that required either gleaning and (or) aerial feeding. Although M. tricolor readily took tethered prey, it did not take any of the variety of insects presented to it in a manner that required gleaning. We therefore compared its wing morphology and echolocation calls with those of several known gleaners, Nycteris thebaica E. Geoffroy, 1818, Myotis lucifugus (Le Conte, 1831), and Myotis septentrionalis (Trouessart, 1897), and an aerial forager, Neoromicia capensis (A. Smith, 1829). In a discriminant analysis wing-tip shape was the only variable to provide some degree of discrimination between species, with M. tricolor having more pointed wing tips than the known gleaners. Discriminant analysis of echolocation-call parameters grouped M. tricolor with the other Myotis species and separated it from N. capensis and N. thebaica. However, M. tricolor did not use harmonics as did the other Myotis species. The apparent failure of M. tricolor to glean might therefore be due to its relatively pointed wings and narrow-bandwidth echolocation calls, owing to the absence of harmonics in its calls.

Self-Structuring in Artificial "Chimps" Offers New Hypotheses for Male Grouping in Chimpanzees

Behaviour ◽  
1994 ◽  
Vol 130 (3-4) ◽  
pp. 229-252 ◽  
Author(s):  
Irenaeus J.A. Te Boekhorst ◽  
Paulien Hogeweg
Keyword(s):  
Empirical Data ◽  
The Other ◽  
Territorial Defense ◽  
Party Membership ◽  
Party Size ◽  
Other Hand ◽  
Competition For Food ◽  
Self Organisation ◽  
The One ◽  
Artificial World

AbstractChimpanzees live in societies that are characterised both by disorder and order. On the one hand, party size fluctuates in a randomlike fashion and party membership is unpredictable ; on the other hand, fundamental party structures are apparent; males are often in all-male parties whereas females remain mostly solitary. The customary sociobiological explanation is based on the assumptions that 1) competition for food favors solitariness (especially in females); 2) chimpanzee males share the costs of territorial defense against rivals from neighbouring communities and 3) genetical relatedness among males within a community compensates for fitness losses due to their competition for food and females. We point to some theoretical flaws in the reasoning that forms the basis of the current neo-Darwinistic model and to the lack of empirical data concerning male relatedness. Most importantly, chimpanzee-like party structures emerge by self-organisation in an artificial "world" in which "CHIMPs" do nothing more than searching for food and mates, without requiring any of the assumptions of the sociobiological model.

Age and food hardness affect food handling by insectivorous bats

2007 ◽  
Vol 85 (9) ◽  
pp. 985-993 ◽  
Author(s):  
E.E. Fraser ◽  
M.B. Fenton
Keyword(s):  
Optimal Foraging ◽  
Feeding Behaviour ◽  
Eating Behaviour ◽  
Myotis Lucifugus ◽  
The Other ◽  
Food Handling ◽  
Insectivorous Bats ◽  
Male And Female ◽  
Food Items ◽  
And Gender

Eating behaviour can vary with age, experience, and gender, as well as food hardness. This variation can contribute to intraspecific dietary differences and may result in variable definitions of optimal foraging and decreased intraspecific competition. We quantified feeding behaviour of insectivorous bats eating hard and soft mealworm-based food items based on the bats’ ability to consume and manipulate food items, consumption time, chew frequency, and total chews to consume. Adult Myotis lucifugus (LeConte, 1831) were more successful at both consuming and manipulating mealworms and consumed mealworms more quickly, with greater chew frequency and in fewer chews, than did subadults. Adults chewed mealworm viscera more frequently than did subadults but showed no differences in the other variables. Adult Eptesicus fuscus (Beauvois, 1796) consumed mealworms more quickly and with fewer chews than did subadults but showed no differences in the other variables. There were no differences between adult and subadult E. fuscus when consuming mealworm viscera. Male and female M. lucifugus did not differ significantly when eating either mealworms or mealworm viscera. There was no change in subadult consumption time of mealworms over the summer. Age-based differences in eating abilities may play a role in defining optimal foraging and dietary composition in insectivorous bats.

The effects of predation risk on the use of social foraging tactics

2004 ◽  
Vol 67 (2) ◽  
pp. 301-308 ◽  
Author(s):  
Zoltán Barta ◽  
András Liker ◽  
Ferenc Mónus
Keyword(s):  
Predation Risk ◽  
Social Foraging ◽  
Foraging Tactics

Dominance, pair bonds and boldness determine social-foraging tactics in rooks, Corvus frugilegus

2013 ◽  
Vol 85 (6) ◽  
pp. 1261-1269 ◽  
Author(s):  
Jolle W. Jolles ◽  
Ljerka Ostojić ◽  
Nicola S. Clayton
Keyword(s):  
Social Foraging ◽  
Pair Bonds ◽  
Corvus Frugilegus ◽  
Foraging Tactics

Two Solitudes: The Behaviour of Pigeons in Competitive Feeding

Behaviour ◽  
2004 ◽  
Vol 141 (4) ◽  
pp. 407-424 ◽  
Author(s):  
◽  
◽  
◽  
◽  
Keyword(s):  
Resource Depletion ◽  
The Other ◽  
Flight Cage ◽  
Significant Difference ◽  
Mere Presence ◽  
Potential Competitor ◽  
Food Conditions ◽  
Access To Food ◽  
As If

AbstractPrevious research showed that pigeons foraging for preferred grains of maize and less preferred grains of wheat respond to the presence of a competitor by becoming less choosy ( i.e. they more readily choose wheat). We extended this work by disentangling the presence of the competitor from the resource depletion associated with it. In Experiment 1, eight birds foraged for maize and wheat in a flight cage. They were tested both alone and with another bird in different foraging sessions. Two groups were formed and differed in how they were treated when the birds foraged in pairs: both birds had access to food (Both Eat) versus only one bird had access to food (Only One Eats) while the other was placed behind a transparent curtain. For the latter treatment, no effect of the mere presence of the other bird on choice was found. Pigeons were, however, less choosy in the presence of a real competitor that exploited the food. At the end of the experiment, the pigeons that had been tested in the 'Both Eat' treatment, were tested in the 'Only One Eats' treatment. They behaved as if foraging alone. Experiment 2 introduced a new condition in which one bird ate and the other was placed behind the curtain where it pecked at grain but could not eat it. Even though this other bird behaved as if it were a potential competitor, it had no effect on the forager in the pair. The only significant difference in choice proportions was between birds foraging in real competition ( i.e. where the other bird caused resource depletion) or not. In competitive feeding situations, pigeons react to what is most directly associated with the dwindling food conditions but are insensitive to the presence and to the pecking behaviour of the animal that creates them.

scholarly journals Cuttlefish show flexible and future-dependent foraging cognition

2020 ◽  
Vol 16 (2) ◽  
pp. 20190743 ◽  
Author(s):  
Pauline Billard ◽  
Alexandra K. Schnell ◽  
Nicola S. Clayton ◽  
Christelle Jozet-Alves
Keyword(s):  
Food Availability ◽  
Feeding Behaviour ◽  
Foraging Behaviour ◽  
Foraging Strategy ◽  
The Other ◽  
Foraging Activity ◽  
Experimental Conditions

Some animals optimize their foraging activity by learning and memorizing food availability, in terms of quantity and quality, and adapt their feeding behaviour accordingly. Here, we investigated whether cuttlefish flexibly adapt their foraging behaviour according to the availability of their preferred prey. In Experiment 1, cuttlefish switched from a selective to an opportunistic foraging strategy (or vice versa ) when the availability of their preferred prey at night was predictable versus unpredictable. In Experiment 2, cuttlefish exhibited day-to-day foraging flexibility, in response to experiencing changes in the proximate future (i.e. preferred prey available on alternate nights). In Experiment 1, the number of crabs eaten during the day decreased when shrimp (i.e. preferred food) were predictably available at night, while the consumption of crabs during the day was maintained when shrimp availability was unpredictable. Cuttlefish quickly shifted from one strategy to the other, when experimental conditions were reversed. In Experiment 2, cuttlefish only reduced their consumption of crabs during the daytime when shrimps were predictably available the following night. Their daytime foraging behaviour appeared dependent on shrimps' future availability. Overall, cuttlefish can adopt dynamic and flexible foraging behaviours including selective, opportunistic and future-dependent strategies, in response to changing foraging conditions.

Intertidal foraging by gentoo penguins in a macroalgal raft

2020 ◽  
Vol 32 (1) ◽  
pp. 43-44
Author(s):  
James B. McClintock ◽  
Charles D. Amsler ◽  
Margaret O. Amsler ◽  
William R. Fraser
Keyword(s):  
Environmental Change ◽  
Foraging Behaviour ◽  
Foraging Strategy ◽  
Foraging Strategies ◽  
Marion Island ◽  
Pygoscelis Papua ◽  
General Consensus ◽  
Foraging Tactics ◽  
Pygoscelid Penguins ◽  
Foraging Tactic

Foraging strategies in gentoo penguins (Pygoscelis papua) have been well studied (e.g. Croxall et al. 1988, Robinson & Hindell 1996, Lescroël et al. 2004, Takahashi et al. 2008, Xavier et al. 2017). The general consensus is this largest member of the three pygoscelid penguins displays both nearshore benthic and pelagic foraging tactics to consume combinations of crustaceans and fish. In a recent study, Carpenter-Kling et al. (2017) reported that gentoos at sub-Antarctic Marion Island displayed a novel foraging strategy that consisted of alternating typical lengthy foraging trips with much shorter nearshore afternoon trips. They suggest the latter foraging behaviour may be a response to suboptimal feeding conditions caused by local environmental change. This novel discovery reinforces the fact that, despite considerable study, not all foraging tactics in penguins have been documented. In this paper, we describe what we believe to be, yet another undocumented foraging tactic employed by gentoos.

scholarly journals Review of the Australian and New Zealand orb-weaving spider genus Novakiella (Araneae, Araneidae)

2021 ◽  
Vol 97 (2) ◽  
pp. 393-405
Author(s):  
Volker W. Framenau ◽  
Cor J. Vink ◽  
Nikolaj Scharff ◽  
Renner L. C. Baptista ◽  
Pedro de S. Castanheira
Keyword(s):  
New Zealand ◽  
Type Species ◽  
Foraging Behaviour ◽  
Base Plate ◽  
The Other ◽  
Museum Specimens

The orb-weaving spider genus Novakiella Court & Forster, 1993 (family Araneidae Clerck, 1757) is reviewed to include two species, N. trituberculosa (Roewer, 1942) (type species, Australia and New Zealand) and N. boletussp. nov. (Australia). Novakiella belongs to the informal, largely Australian ‘backobourkiine’ clade and shares with the other genera of the clade a single macroseta on the male pedipalp patella and a median apophysis of the male pedipalp that forms an arch over the radix. The proposed genus synapomorphies are the presence of a large basal conductor lobe expanding apically over the radix and the shape of the median apophysis, which extends into a basally directed, pointy projection. Males have an apico-prolateral spur on the tibia of the second leg that carries a distinct spine. Females have an epigyne with triangular base plate bearing transverse ridges and an elongate triangular scape, which is almost always broken off. The humeral humps of the abdomen are distinct. Novakiella trituberculosa build characteristic dome-shaped webs; however, the foraging behaviour and web-shape of N. boletussp. nov., currently only known from museum specimens, are not known.

scholarly journals Examining the influence of nudges on children's fruit and vegetable consumption

2019 ◽  
Author(s):  
Maxine Sharps ◽  
Eleanor Thomas ◽  
Jacqueline Blissett
Keyword(s):  
Vegetable Consumption ◽  
Eating Behaviour ◽  
Fruit And Vegetable Consumption ◽  
Portion Size ◽  
The Other ◽  
Children's Health ◽  
Children’S Health ◽  
Healthy Weight ◽  
Fruit And Vegetable ◽  
Control Study

Purpose: Children’s fruit and vegetable consumption is lower than recommended and increasing consumption is important for children’s health. Nudges influence children’s eating behaviour, but less is known about their influence on children’s fruit and vegetable consumption. Two studies were conducted to examine this. Methods: Study 1 examined whether a fruit nudge (an image of grapes) on a plate influenced children’s fruit (grapes) consumption relative to a control condition (no image). In a between-subjects design, children (n=63, Mean age=8.9 years, SD=1.41, 38 females, 25 males, 73% had a healthy-weight) were randomly assigned to one of two conditions (fruit nudge vs. control). Study 2 examined the influence of a large portion nudge (an image of a large portion of carrots) vs. a small portion nudge (an image of a small portion of carrots) vs. control (no nudge) on children’s vegetable (carrot) consumption. In a between-subjects design, children (n=60, Mean age=8.53 years, SD=2.14, 31 females, 29 males, 85% had a healthy-weight) were randomly assigned to a condition. Results: In Study 1 children consumed significantly more fruit in the fruit nudge condition than the control condition. In Study 2 children exposed to the large portion nudge ate significantly more vegetables than the other two conditions. The small portion nudge did not affect children’s vegetable consumption relative to control. Conclusions: The results indicate that nudges influence children’s fruit and vegetable consumption, and that the portion size of the nudge may be key to whether the nudge influences children’s eating behaviour.

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