Predatory behaviour and prey-capture decision-making by the web-weaving spider Micrathena sagittata

2005 ◽  
Vol 83 (2) ◽  
pp. 268-273 ◽  
Author(s):  
Francisco Díaz-Fleischer
Keyword(s):  
Prey Item ◽  
Prey Capture ◽  
Prey Size ◽  
Prey Type ◽  
Optimal Foraging Theory ◽  
Choice Test ◽  
Large Prey ◽  
Predatory Behaviour ◽  
Hunting Behaviour ◽  
The Web

Optimal-foraging theory predicts how a predator would feed most efficiently when faced with a choice of two types of prey differing in profitability and density in the habitat. The predator should focus only on the more profitable prey, since any prey item eaten by the predator has a cost in terms of the time and resources taken to subdue and eat it. A study of the hunting behaviour and prey-type selection of the web-weaving spider Micrathena sagittata (Walckenaer, 1841) (Araneae: Araneidae) in the field is documented. In the first part of the study, prey of two sizes were offered in four sectors of the web (top, bottom, right, and left). A prey item was provided at one position of the web at a time. Attack time was recorded at each position. Also, choice and no-choice tests were carried out by offering prey in opposing web sectors (top and bottom) simultaneously. Large prey were more successfully captured in the upper parts than in the bottom parts of the web. In the choice test, spiders always preferred large prey to small prey, while in the no-choice test, spiders always responded to the first stimulus received. Two different attack strategies, depending on prey size, were observed. Hunting strategies and prey-size preference can be related to the cost of web construction and profitability of the prey type.

Feeding Habits and Predatory Behaviour in the Marbled Polecat (Vormela Peregusna Syriaca): I. Killing Methods in Relation To Prey Size and Prey Behaviour

Behaviour ◽  
1991 ◽  
Vol 118 (1-2) ◽  
pp. 127-143 ◽  
Author(s):  
Merav Ben-David ◽  
Sergio M. Pellis ◽  
Vivien C. Pellis
Keyword(s):  
Prey Capture ◽  
Prey Size ◽  
Feeding Habits ◽  
Large Prey ◽  
Predatory Behaviour ◽  
Medical Laboratories ◽  
Ecological Aspects ◽  
In Captivity ◽  
In The Wild ◽  
Meriones Tristrami

AbstractThe marbled polecat (Vormela peregusna syriaca), a small musteline, is represented in the fauna of Israel. Predatory behaviour of eleven marbled polecats, caught in the field, and held in captivity for a reproductive biology study, was observed during their routine feedings over the course of two years. Sequences of prey capture and killing were recorded on film or videotape. Killed prey were also retrieved for autopsy. Prey offered included Gallus gallus domesticus, Mus musculus, Acomys cahirinus, Microtus guentheri, Meriones tristrami, Cavia porcellus and Rattus norvegicus. All prey items were obtained as surplus from medical laboratories. In addition to using the typical musteline killing method of biting the nape of the neck, marbled polecats used a variety of killing methods suited to a range of prey types. Two variables determined the killing method used. 1) Size of prey: Small prey were killed by bites to the thorax, whereas large prey were bitten on the head or neck. 2) Prey defense behaviour: Fleeing prey were bitten dorsally, whereas defending prey were bitten ventrally, typically on the throat. This non-stereotypical predatory behaviour appears to correlate with the opportunistic feeding habits of marbled polecats in the wild. Evolutionary and ecological aspects of this relationship are discussed.

Quantitative analysis of feeding kinematics in dusky salamanders (Desmognathus)

1988 ◽  
Vol 66 (6) ◽  
pp. 1309-1317 ◽  
Author(s):  
John H. Larsen Jr. ◽  
John T. Beneski Jr.
Keyword(s):  
Quantitative Analysis ◽  
Prey Item ◽  
Prey Capture ◽  
Large Prey ◽  
Selective Force ◽  
Mandibular Symphysis ◽  
Lower Jaw ◽  
Feeding Kinematics

Gape formation by the dusky salamander (Desmognathus) involves both upper and lower jaws and occurs in a manner similar to that of other terrestrial salamanders. As Desmognathus opens its mouth, ventral rotation of the mandibles is restricted but not stopped by the atlas–mandibular ligaments; the lower jaw is not propelled anteriorly. Tongue protraction, well beyond the mandibular symphysis, is always a major component of prey capture by this genus. After the sticky tongue pad has made contact with the prey, the salamander's head surges forward and the pad is rapidly retracted with the prey item attached. Aided by a unique suite of characters the mouth then snaps shut with considerable force. Our study supports the premise that Desmognathus is no different from most, if not all, terrestrial salamanders in its employment of tongue projection as a major feature in prey capture. We argue that the primary selective force for the unique configuration of desmognathine cephalic structures was enhancement of the ability of these small salamanders to capture relatively large prey without an increase in the size of the head and body.

The Inactivity of Animals: Influence of Stochasticity and Prey Size

Behaviour ◽  
1985 ◽  
Vol 92 (1-2) ◽  
pp. 1-8 ◽  
Author(s):  
Dorian Moss ◽  
William J. Sutherland
Keyword(s):  
Food Supply ◽  
Prey Capture ◽  
Prey Size ◽  
Large Prey ◽  
Small Prey ◽  
Sufficient Food

As a consequence of prey capture being partly dependent upon chance, each individual may usually spend much of the day inactive even if the population is limited by its food supply. This applies particularly to species that eat large prey and thus experience considerable day-to-day variation in intake which restricts them to relatively rich habitats. Food will be found easily on most days and little time need be spent hunting although, occasionally, they will be unlucky and, despite searching all day, risk starvation. Predators of small prey can survive in environments that provide barely sufficient food as they experience little variation in intake: but they need to search all day to sustain themselves.

Modulation of prey-capture behavior in the plethodontid salamander Ensatina eschscholtzii

1997 ◽  
Vol 200 (14) ◽  
pp. 1951-1964 ◽  
Author(s):  
S Deban
Keyword(s):  
High Speed ◽  
Sensory Feedback ◽  
Prey Capture ◽  
Prey Size ◽  
Sensory Information ◽  
Prey Type ◽  
Jaw Movements ◽  
Plethodontid Salamander ◽  
Ensatina Eschscholtzii ◽  
Prey Capture Behavior

The hypothesis that salamander prey-capture behavior is highly stereotyped was tested in the plethodontid salamander Ensatina eschscholtzii using high-speed videography and kinematic analysis of feedings on two types of prey (waxworms and termites). The results show that E. eschscholtzii is capable of modulating the timing and magnitude of tongue and jaw movements in response to prey type. Feedings on waxworms, the larger prey, were characterized by shorter durations and higher velocities of tongue and jaw movements compared with feedings on termites, particularly in the latter portion of the feeding sequence (i.e. after prey contact). To test the hypothesis that sensory feedback through the tongue pad plays a role in modulating feeding movements in response to prey type, the ramus lingualis of the glossopharyngeal nerve (cranial nerve IX), which is known to carry sensory information from the tongue pad in salamanders, was transected bilaterally. This experimental deafferentation of the tongue pad had no effect on the degree or direction of differences in feeding kinematics across prey type. These results refute the glossopharyngeal feedback hypothesis, but are consistent with the hypothesis that E. eschscholtzii responds more vigorously to larger prey by assessing prey size visually.

Do snakes exhibit shifts in feeding ecology associated with the presence or absence of potential competitors? A case study from tropical Africa

2003 ◽  
Vol 81 (2) ◽  
pp. 228-236 ◽  
Author(s):  
Luca Luiselli
Keyword(s):  
Feeding Ecology ◽  
Prey Size ◽  
Prey Type ◽  
Swamp Forest ◽  
Southeastern Nigeria ◽  
Predator Species ◽  
Predatory Behaviour ◽  
Ecological Requirements ◽  
Predator Size ◽  
Potential Competitor

Two species of rain-forest snakes, the colubrids Natriciteres fuliginoides and Natriciteres variegata, are potential competitors, because they attain, on average, the same body size (20–30 cm long), have similar habits and ecological requirements (they are both diurnal and nocturnal, often semi-aquatic), and have similar dietary spectra ( including both small vertebrates and invertebrates). I studied prey type and predator size – prey size relationships of these snakes in four swamp-forest areas of southeastern Nigeria (West Africa): only N. fuliginoides was found in two of these areas, whereas both species were common in the other two areas. The feeding ecology of N. fuliginoides shifted greatly in the presence of its potential competitor, N. variegata, in terms of prey-type preferences and predatory behaviour as well as in terms of predator size – prey size relationships. In particular, the effects of the potential competitor on the feeding ecology of N. fuliginoides were (i) a shift toward eating many invertebrates from a diet based on many small vertebrates, (ii) a shift toward eating many terrestrial organisms from a diet based on many aquatic organisms, and (iii) a shift in mean prey size for females toward relatively larger prey from a diet based on smaller prey. The resulting effect was a clear partitioning of food resources between the two predator species in both the areas where they are sympatric, whereas N. fuliginoides had a wider dietary spectrum (covering that of the two species together) in the areas where its competitor is not found. The role of intraspecific competition seems less strong, as no apparent resource partitioning in prey type or prey size was observed between males and females of either species or in any study area. However, mean prey size was significantly greater for females than for males of both species and in all study areas, but depended on the significant reverse sexual size dimorphism observed in both species.

Selection of Prey by Size in Ningaui Yvonneae

1996 ◽  
Vol 44 (3) ◽  
pp. 319 ◽  
Author(s):  
AP Woolnough ◽  
SM Carthew
Keyword(s):  
Energy Efficient ◽  
Prey Size ◽  
Handling Time ◽  
Optimal Foraging Theory ◽  
Large Prey ◽  
Small Prey ◽  
Upper Limit ◽  
The Relationship ◽  
Prey Items ◽  
Selection Of

The small dasyurid marsupial, Ningaui yvonneae, feeds opportunistically on invertebrates dominated by the orders Hymenoptera, Coleoptera and Araneae, but is capable of, and will, consume vertebrates such as skinks. When presented with a choice of prey N. yvonneae exhibited a strong preference for prey items on the basis of size. It consistently selected small prey items over large prey items. Small prey items represented the most energy-efficient prey option as the ningaui can more efficiently capture, subdue and consume them than it can larger prey. The relationship between prey size and handling time was exponential, indicating that there is an upper limit to the ability of N. yvonneae to process prey. Moreover, smaller cockroaches provided greater energy gain than larger ones, indicating that the costs of eating larger cockroaches energetically outweighed the energy return. These results are in agreement with optimal foraging theory.

scholarly journals Flexibility in feeding behaviour may compensate for morphological constraints of fossoriality in the amphisbaenian Blanus cinereus

2013 ◽  
Vol 34 (2) ◽  
pp. 241-247 ◽  
Author(s):  
Pilar López ◽  
Pilar López ◽  
José Martín ◽  
Pilar López ◽  
José Martín ◽  
...  
Keyword(s):  
Feeding Behaviour ◽  
Prey Capture ◽  
Prey Type ◽  
Large Prey ◽  
Morphological Adaptation ◽  
Trophic Resources ◽  
Morphological Adaptations ◽  
Small Head ◽  
Gape Size

Morphological adaptations for burrowing, such as an elongated body, and a small head may constrain feeding behaviour in fossorial reptiles. We experimentally examined the effect of prey type on prey capture and handling behaviour of the amphisbaenian Blanus cinereus. This amphisbaenian showed four different handling modes according to the characteristics of each prey type. When prey diameter was narrower than gape-size, prey were consumed without prey processing; when prey diameter was wider than gape-size, B. cinereus shifted handling mode to prey processing. Amphisbaenians scraped or tore off bite-sized pieces of large prey and showed longer handling times for some prey types than most epigean saurians. Flexibility in feeding behaviour may allow amphisbaenians to exploit variable underground trophic resources, overcoming constraints of morphological adaptation to fossoriality.

The Ontogeny of Predatory Behaviour in the Golden Hamster (Mesocricetus a. Auratus). IV. Effects of Prolonged Exposure, Iti, Size of Prey and Selective Breeding

Behaviour ◽  
1978 ◽  
Vol 65 (1-2) ◽  
pp. 27-41 ◽  
Author(s):  
Polsky Richard H.
Keyword(s):  
Selective Breeding ◽  
Prolonged Exposure ◽  
Prey Capture ◽  
Locusta Migratoria ◽  
Relative Size ◽  
Future Research ◽  
Large Prey ◽  
Repeated Testing ◽  
Predatory Behaviour ◽  
The Stability

As an outgrowth of previous experimental work (POLSKY, 1977a, 1977b, 1977c) this paper presents findings which examined the influence of the following variables on the development of predatory behaviour in golden hamsters (M. a. auratits) : (a) prolonged exposure to the prey; (b) the interval between successive prey presentations (ITI) ; (c) the size of prey, and (d) selective breeding. Nymphs of Locusta migratoria served as prey. The basic methodology consisted of testing naive hamsters individually for the capture of a locust in their own home compartment. The principal measure was latency to capture; in addition, in Experiment 3 the frequency of exploration of the prey, withdrawal from the prey, nip at the prey and unsuccessful capture were recorded. Results showed: 1. Increasing familiarization with the prey via prolonged exposure resulted in an increase in the incidence of capture. 2. Latency to capture decreased significantly with repeated testing when the prey was presented at intervals of five or ten days; no significant decrease occurred when the prey was presented at intervals of one day. Further, the response of capture remained intact in established captors after a period of seventy days without the opportunity for capture. 3. Large prey were captured with relatively high latencies by forty day old hamsters; overall, forty day old hamsters, when compared with seventy day old hamsters, also showed a greater frequency of the behaviours associated with capture. 4. Prey capture was susceptible to the effects of selective breeding. The above results were discussed within the framework of habituation (Experiment i), methodological procedures and the stability of the prey capture response (Experiment 2), the relative size between predator and prey (Experiment 3) and genetic predispositions for capture (Experiment 4). Areas for future research were suggested.

The Ontogeny of Predatory Behaviour in the Golden Hamster (Mesocricetus a. Auratus). Iv. Effects of Prolonged Exposure, Iti, Size of Prey and Selective Breeding

Behaviour ◽  
1978 ◽  
Vol 65 (1-2) ◽  
pp. 27-41 ◽  
Author(s):  
Polsky Richard H.
Keyword(s):  
Selective Breeding ◽  
Prolonged Exposure ◽  
Prey Capture ◽  
Locusta Migratoria ◽  
Relative Size ◽  
Future Research ◽  
Large Prey ◽  
Repeated Testing ◽  
Predatory Behaviour ◽  
The Stability

As an outgrowth of previous experimental work (POLSKY, 1977a, 1977b, 1977c) this paper presents findings which examined the influence of the following variables on the development of predatory behaviour in golden hamsters (M. a. auratus) : (a) prolonged exposure to the prey; (b) the interval between successive prey presentations (ITI) ; (c) the size of prey, and (d) selective breeding. Nymphs of Locusta migratoria served as prey. The basic methodology consisted of testing naive hamsters individually for the capture of a locust in their own home compartment. The principal measure was latency to capture; in addition, in Experiment 3 the frequency of exploration of the prey, withdrawal from the prey, nip at the prey and unsuccessful capture were recorded. Results showed: 1. Increasing familiarization with the prey via prolonged exposure resulted in an increase in the incidence of capture. 2. Latency to capture decreased significantly with repeated testing when the prey was presented at intervals of five or ten days; no significant decrease occurred when the prey was presented at intervals of one day. Further, the response of capture remained intact in established captors after a period of seventy days without the opportunity for capture. 3. Large prey were captured with relatively high latencies by forty day old hamsters; overall, forty day old hamsters, when compared with seventy day old hamsters, also showed a greater frequency of the behaviours associated with capture. 4. Prey capture was susceptible to the effects of selective breeding. The above results were discussed within the framework of habituation (Experiment 1), methodological procedures and the stability of the prey capture response (Experiment 2), the relative size between predator and prey (Experiment 3) and genetic predispositions for capture (Experiment 4). Areas for future research were suggested.

Potential of prey size and type to affect foraging asymmetries in tiger salamander (Ambystoma tigrinum nebulosum) larvae

2003 ◽  
Vol 81 (10) ◽  
pp. 1726-1735 ◽  
Author(s):  
Eric B Johnson ◽  
Paulette Bierzychudek ◽  
Howard H Whiteman
Keyword(s):  
Size Structure ◽  
Prey Size ◽  
Interference Competition ◽  
Prey Type ◽  
Foraging Efficiency ◽  
Ambystoma Tigrinum ◽  
Tiger Salamander ◽  
Predator Population ◽  
Large Prey ◽  
Ambystoma Tigrinum Nebulosum

Although competitive interactions within predator populations are known to depend on their size structure, we understand less about how these interactions are influenced by prey characteristics. Most studies of such interactions for tiger salamander (Ambystoma tigrinum nebulosum) larvae have used small zooplankton prey. We investigate the potential of exploitation and interference competition to influence the success of tiger salamander larvae feeding on relatively large prey, mayfly and damselfly larvae. We measured salamander foraging efficiency for a range of salamander and prey sizes and observed aggression levels of salamanders of varying size housed together. Exploitative foraging efficiency (captures per attempts) increased with salamander size but was better predicted by relative prey size (prey size as a percentage of salamander snout–vent length) than by salamander size alone; it also depended significantly on prey type. Aggression (interference) levels were higher when prey were present, and larger salamanders were more aggressive than smaller ones but did not consume more mayfly prey. Our results suggest that investigating the environmental conditions, particularly the prey characteristics, that influence size-based competitive advantages will lead to a better understanding of predator population dynamics.

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