Prey preferences of Phaeacius malayensis, a spartaeine jumping spider (Araneae: Salticidae) from Singapore

2000 ◽  
Vol 78 (12) ◽  
pp. 2218-2226 ◽  
Author(s):  
Daiqin Li
Keyword(s):  
Optimal Foraging ◽  
Prey Type ◽  
Optimal Foraging Theory ◽  
Simultaneous Presentation ◽  
Adaptive Significance ◽  
Alternative Prey ◽  
Jumping Spider ◽  
Jumping Spiders ◽  
Prey Preferences ◽  
Different Types

Phaeacius malayensis (Salticidae: Spartaeinae) is an atypical jumping spider that routinely includes other jumping spiders in its diet. This paper presents the first detailed study of P. malayensis' prey preferences. Three basic types of tests of prey preference were used: different types of prey were provided on alternate days (alternate-day tests), two types of prey were provided simultaneously (simultaneous-presentation tests), and an alternative prey type was provided while the predator was already feeding (alternative-prey tests). In alternate-day and simultaneous-presentation testing, but not in alternative-prey testing, (i) P. malayensis preferred spiders (salticids and hunting spiders) to insects; (ii) P. malayensis preferred salticids to hunting spiders; (iii) these preferences were not exhibited in some paired choices when the background was nonmatching, indicating that visual concealment is important with respect to some, but not all, prey; (iv) P. malayensis' prey preferences were not affected by a prior 14-day period without food; (v) after 21 days of fasting, P. malayensis took different types of prey indiscriminately. The adaptive significance of preferences for particular types of prey is discussed in the context of optimal-foraging theory.

scholarly journals The influence of camouflage and prey type on predatory decisions of jumping spider

2013 ◽  
Vol 9 ◽  
pp. 26-34
Author(s):  
Maciej Bartos
Keyword(s):  
Prey Type ◽  
Predatory Behavior ◽  
Background Color ◽  
Jumping Spider ◽  
Jumping Spiders ◽  
Multiple Factors ◽  
Background Matching ◽  
Factors Influencing

Decisions made by predators during predatory encounters are often based on multiple factors that may influence the outcome of the encounters. For stalking predators their visibility to the prey and the ability of their prey to escape may be important factors influencing predatory success. Hence they are likely to adapt their predatory behavior when approaching prey on backgrounds with different camouflaging properties, but only if the prey is able to escape. To test whether jumping spiders flexibly adapt their predatory behavior to camouflaging properties of the background and prey type, the behavior of Yllenus arenarius (Araneae, Salticide), a cryptically colored jumping spider hunting leafhoppers (high escape potential) and caterpillars (low escape potential) on two types of background: matching and non-matching for the spiders was analyzed. Background color had a significant effect on the spiders’ jumping distance and their predatory success, but only if the prey had a high escape potential. No differences occurred between backgrounds if the prey could not escape. On camouflaging background the spiders attacked leafhoppers from a shorter distance and had a higher success than on non-camouflaging background.

Are great tits (Parus major) really optimal foragers?

2003 ◽  
Vol 81 (5) ◽  
pp. 780-788 ◽  
Author(s):  
Michal Berec ◽  
Vlastimil Krivan ◽  
Ludek Berec
Keyword(s):  
Optimal Foraging ◽  
Parus Major ◽  
Random Order ◽  
Prey Type ◽  
Optimal Foraging Theory ◽  
Conveyor Belt ◽  
Critical Value ◽  
Foraging Theory ◽  
Functional Responses ◽  
Prey Model

In this study, we test the classical prey model of optimal-foraging theory with great tits (Parus major) feeding on two types of mealworms presented on a conveyor belt. Contrary to the results of some previous experiments, prey types were given to birds in random order, therefore birds could not predict their next prey item. We tested birds' diet choices at four different prey-encounter rates. Our results show that in 95% of cases great tits consumed the more profitable prey type upon encounter. On the other hand, consumption of the less profitable prey type did not differ statistically from the "always-attack" strategy in 77% of cases when the rate of encounter with the more profitable prey was below a critical value, and did differ from that strategy in 67% of cases when the rate of encounter with the more profitable prey was above that critical value. Contrary to predictions of the classical prey model of optimal-foraging theory, our birds never completely excluded the less profitable prey type from their diet. We also estimated the functional responses of individual birds with respect to the more profitable prey type; birds' diet changes occurred too slowly to make these functional responses stabilizing.

scholarly journals Be different to be better: the effect of personality on optimal foraging with incomplete knowledge

2021 ◽  
Author(s):  
Poppy M. Jeffries ◽  
Samantha C. Patrick ◽  
Jonathan R. Potts
Keyword(s):  
Optimal Foraging ◽  
Optimal Foraging Theory ◽  
Foraging Strategy ◽  
Foraging Strategies ◽  
Partial Knowledge ◽  
Marginal Value ◽  
Animal Populations ◽  
Plausible Mechanism ◽  
Insight Into ◽  
Modelling Approach

AbstractMany animal populations include a diversity of personalities, and these personalities are often linked to foraging strategy. However, it is not always clear why populations should evolve to have this diversity. Indeed, optimal foraging theory typically seeks out a single optimal strategy for individuals in a population. So why do we, in fact, see a variety of strategies existing in a single population? Here, we aim to provide insight into this conundrum by modelling the particular case of foraging seabirds, that forage on patchy prey. These seabirds have only partial knowledge of their environment: they do not know exactly where the next patch will emerge, but they may have some understanding of which locations are more likely to lead to patch emergence than others. Many existing optimal foraging studies assume either complete knowledge (e.g. Marginal Value Theorem) or no knowledge (e.g. Lévy Flight Hypothesis), but here we construct a new modelling approach which incorporates partial knowledge. In our model, different foraging strategies are favoured by different birds along the bold-shy personality continuum, so we can assess the optimality of a personality type. We show that it is optimal to be shy (resp. bold) when living in a population of bold (resp. shy) birds. This observation gives a plausible mechanism behind the emergence of diverse personalities. We also show that environmental degradation is likely to favour shyer birds and cause a decrease in diversity of personality over time.

Optimal foraging: theory and experiment

Nature ◽  
1977 ◽  
Vol 268 (5621) ◽  
pp. 583-584 ◽  
Author(s):  
John Krebs
Keyword(s):  
Optimal Foraging ◽  
Optimal Foraging Theory ◽  
Foraging Theory ◽  
Theory And Experiment
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