Resource-Dependent Giving-Up Time of the Predatory Mite, Phytoseiulus persimilis

We examined the effect of prey (Tetranychus urticae) egg density on leaving rate of the predatory mite, Phytoseiulus persimilis, from leaf disks using predators with different feeding experiences and levels of external volatile cues related to their prey. Predators stayed longer on disks with prey eggs than on those without prey eggs. However, at each prey egg density predators stayed longer in the absence of prey-related volatiles from an external source. Starved predators stayed longer in a prey patch than those that had not experienced starvation. At each prey density, starved P. persimilis consumed a greater proportion of prey eggs than satiated predators. The total prey consumption of starved predators appears to be related to their longer residence time on source disks compared to satiated predators and also the per capita consumption rate was greater for starved predators compared to satiated predators.     

The effect of rearing the ladybirdHarmonia axyridis onEphestia kuehniella eggs on the response of its larvae to aphid tracks

Larvae ofHarmonia axyridis Pallas (Col., Coccinellidae) exhibited two walking patterns during prey search. Extensive search occurred when searching for prey patches and was characterized by long linear paths and a fast speed. Intesive search, which appeared after the ingestion of a prey in a patch, resulted from a lowering of the linear speed and an increase in the number of stops and angular speed. When larvae reared on the aphidAcyrthosiphum pisum Harris (Hom., Aphidae) crossed an artificial substratum previously contaminated by this prey, they changed their path direction and adopted intensive search. They probably perceived aphid odor tracks and consequently modified their walking pattern. This gustatory capacity probably allowed very mobile larvae to locate prey patches more rapidly and improve encounter with preys in every patch.H. axyridis larvae reared on a substitute prey, the eggs ofEphestia kuehniella Zeller (Lep., Pyralidae), for more than a hundred generations, also changed their path orientation but retained extensive search. The weak response of these larvae to aphid tracks may have resulted from either a decrease in their sensitivity to gustatory aphid stimuli or their difficulty in associating aphid odor with aphid presence. These larvae needed more time and more preliminary encounters than larvae reared on aphids before catching prey.     

Capture efficiency and trophic adaptations of a specialist and generalist predator: A comparison

Specialist true predators are expected to exhibit higher capture efficiencies for the capture of larger and dangerous prey than generalist predators due to their possession of specialized morphological and behavioral adaptations. We used an araneophagous spider (Lampona murina) and a generalist spider (Drassodes lapidosus) as phylogenetically related model species and investigated their realized and fundamental trophic niches and their efficacy with respect to prey capture and prey handling. The trophic niche of both species confirmed that Lampona had a narrow trophic niche with a predominance of spider prey (including conspecifics), while the niche of Drassodes was wide, without any preference. DNA analysis of the gut contents of Lampona spiders collected in the field revealed that spiders form a significant part of its natural diet. Lampona captured significantly larger prey than itself and the prey captured by Drassodes. As concerns hunting strategy, Lampona grasped the prey with two pairs of legs possessing scopulae, whereas Drassodes immobilized prey with silk. Lampona possess forelegs equipped with scopulae and a thicker cuticle similar to other nonrelated araneophagous spiders. Lampona fed for a longer time and extracted more nutrients than Drassodes. We show that specialized behavioral and morphological adaptations altogether increase the hunting efficiency of specialists when compared to generalists.     

Diet and prey selection of sympatric tropical skinks

Most skinks are opportunistic predators, taking available prey from the environment as it is encountered. Variation in their diet composition is thought to reflect differences in prey abundance in the environment. We studied diet composition and prey selection in a community of three sympatric skink species (genus Carlia) in northern Australia by comparing contents of skink stomachs with arthropod prey available in their habitat. Carlia were entirely carnivorous and fed on a range of arthropod prey. We found high overlap in diet and prey size among the three species and between the wet and dry seasons, but found that skinks generally focused their foraging efforts on prey types and prey sizes that were not abundant in the habitat. Spiders (Aranea), orthopterans, blattarians, isopods and termites (Isoptera) were important prey of skinks, but these arthropods were rarely trapped in the environment. Skinks also frequently consumed large‐bodied prey, despite the higher relative abundance of small prey in the environment. Skinks were more selective in their foraging and diet than previously assumed. Selection of prey by consumers is a fundamental ecological process, important to consumers for maintaining energy requirements to grow and reproduce, but equally important to the community dynamics of the prey consumed.     

The reaction time of leech and triclad species to crushed prey and the significance of this for their coexistence in British lakes

1. Three species of leeches, Erpobdella octoculata, Glossiphonia complanata and Helobdella stagnalis, and four species of triclads, Polycelis nigra, P. tennis, Dugesia polychroa and Dendrocoelum lacteum, commonly coexist on stony shores in productive British lakes. All species are food limited and there is much overlap in their diet. For both leech and triclad communities, coexistence of species is through the occurrence of food refuges. Leeches are more successful than triclads at capturing live prey, whereas both groups feed on damaged prey, comprising incapacitated, live or dead animals that are leaking body fluids. If triclads are better than leeches at exploiting damaged prey, this could be a mechanism for their coexistence. 2. Laboratory experiments investigated the comparative speeds at which leeches and triclads responded to crushed prey. Young and adult predators were offered a crushed specimen of the oligochaete Tubifex tubifex, the snail Lymnaea peregra, the crustacean Asellus aquaticus or the chironomid Chironomus sp., and their reaction times recorded. These four prey groups constitute the main diet of the predators in the field. Only D. polychroa and D. lacteum showed a significantly different reaction time between young and adults to crushed prey, and the reason for this is unclear. All predators, except H. stagnalis and D. polychroa, showed a difference in reaction time to the four types of prey, presumably a consequence of differences in both the ‘quality’ and ‘concentration’ of the different prey fluids, and there were some differences between predators in their speed of reaction to the same prey type. The following sequence, from fastest to slowest, in general reaction time to prey was obtained: E. octoculata, D. polychroa, P. tenuis, D. lacteum, P. nigra, H. stagnalis and G. complanata. 3. The location of the damaged food by the predators can be explained partly in terms of their foraging behaviour, with E. octoculata, D, polychroa and P. tenuis exhibiting a more seek-out strategy than other species which have a more sit-and-wait behaviour, and partly on the level of sophistication of their chemosensory system used to detect leaked prey fluids. This system is highly developed in triclad species but poorly developed in leeches. 4. In a second type of experiment in which prey, L. peregra, A. aquaticus or Chironomus sp., were offered at different time intervals after crushing to H, stagnalis and P. tenuis, few predators fed on food crushed for 24 h or longer, although a few leeches fed on Chironomus crushed for up to 72 h. 5. It is concluded that coexistence of leech and triclad species on stony shores in lakes is assisted by partitioning of food on a damaged or live basis.     

Coevolution of a marine gastropod predator and its dangerous bivalve prey

The fossil record of the interaction between the predatory whelk Sinistrofulgur and its dangerous hard‐shelled bivalve prey Mercenaria in the Plio‐Pleistocene of Florida was examined to evaluate the hypothesis that coevolution was a major driving force shaping the species interaction. Whelks use their shell lip to chip open the shell of their prey, often resulting in breakage to their own shells, as well as to their prey. Mercenaria evolved a larger shell in response to an intensifying level of whelk predation. Reciprocally, an increase in attack success (ratio of successful to unsuccessful attacks) and degree of stereotypy of attack position by the predator suggest reciprocal adaptation by Sinistrofulgur to increase efficiency in exploiting hard‐shelled prey. A decrease in prey effectiveness (ratio of unsuccessful to total whelk predation attempts) and an increase in the minimum boundary of a size refuge from whelk predation for Mercenaria may indicate that predator adaptation has outpaced prey antipredatory adaptation. Evolutionary size increase in Sinistrofulgur most likely occurred in response to prey adaptation to decrease the likelihood of feeding‐induced shell breakage and unsuccessful predation when encounters with damage‐inducing prey occur, coupled with (or reinforced by) an evolutionary response to the whelk's own predators. Predator adaptation to Mercenaria best explains temporal changes in whelk behaviour to decrease performance loss (shell breakage) associated with feeding on hard‐shelled prey; this behavioural change limits attacks on prey to when the whelk's shell lip is thickest and most resistant to breakage. Despite evidence of reciprocal adaptation between predator and prey, the contribution of Mercenaria to Sinistrofulgur evolution is likely only a component of the predator's response to dangerous bivalve prey. This study highlights the importance of understanding the interactions among several species in order to provide the appropriate context to test evolutionary hypotheses about any specific pair of species. © 2003 The Linnean Society of London, Biological Journal of the Linnean Society, 2003, 80 , 409–436.     

Attraction of Allodorylaimus americanus (Nematoda: Dorylaimida) towards different prey nematodes and factors influencing this attraction

Abstract

The attraction of Allodorylaimus americaus towards excised (cut into two pieces) and non-excised (live) individuals of plant parasitic nematodes viz., Tylenchorhynchus mashhoodi, Hoplolaimus indicus, Helicotylenchus indicus, Hirschmanniella oryzae, Xiphinema americanum and Hemicriconemoides mangiferae used as prey were tested in a Petri dish. A. americanus responded positively and significantly to prey kairomones but showed variation in their individual behaviour. A. americanus was most attracted towards excised individuals of T. mashhoodi. The differential responses of A. americanus towards different prey were attributed to the inert behaviour of the predator, their preference for a particular species of prey, chemical composition, concentration, quality, quantity of prey attractant, formation of minimum perceptible attraction gradient of prey and minimum response threshold of predators. Different factors such as temperature, period of prey incubation, prey density, starvation of predators, agar concentration, and agar thickness governed the attraction responses of the predator. A. americanus responded maximally towards T. mashhoodi, when tested as 5-day starved predators in agar plates containing a 2 mm thick layer of 1% water-agar with 200 prey individuals previously incubated for 16 h at 30°C.     

Prey to predator size ratio influences foraging efficiency of larval Aeshna juncea dragonflies

We investigated foraging behaviour of larval dragonflies Aeshna juncea in order to examine the significance of prey density and body size in predator-prey dynamics. A. juncea were offered separately three size-classes of Daphnia magna at low and high densities. The data were collected with direct observations of the foraging individuals. We found that large A. juncea larvae could better enhance their intake of prey biomass as prey size and prey density increased than their smaller conspecifics. However, increasing feeding efficiency of both larval instars was constrained by declining attack success and search rate with increasing prey size and density. With small D. magna, in contrast to large A. juncea, small A. juncea increased their searching efficiency as prey density increased keeping D. magna mortality rate at a constant level. In a predator-prey relationship this indicates stabilizing potential and feeding thresholds set by both prey density and prey-predator size ratio. Attack success dropped with prey size and density, but did not change in the course of the foraging bout. For both A. juncea sizes prey handling times increased as more medium and large prey were eaten. The slope of the increase became steeper with increasing prey-predator size ratio. These observations indicate that components of the predator-prey relationship vary with prey density, contrary to the basic assumptions of functional response equations. Moreover, the results suggest that the effects of prey density change during the ontogeny of predators and prey.     

Predator hunting modes and predator–prey space games

Predators and prey are often engaged in a game where their expected fitnesses are affected by their relative spatial distributions. Game models generally predict that when predators and prey move at similar temporal and spatial scales that predators should distribute themselves to match the distribution of the prey's resources and that prey should be relatively uniformly distributed. These predictions should better apply to sit-and-pursue and sit-and-wait predators, who must anticipate the spatial distributions of their prey, than active predators that search for their prey. We test this with an experiment observing the spatial distributions and estimating the causes of movements between patches for Pacific tree frog tadpoles (Pseudacris regilla), a sit-and-pursue dragonfly larvae predator (Rhionaeschna multicolor), and an active salamander larval predator (Ambystoma tigrinum mavortium) when a single species was in the arena and when the prey was with one of the predators. We find that the sit-and-pursue predator favors patches with more of the prey's algae resources when the prey is not in the experimental arena and that the prey, when in the arena with this predator, do not favor patches with more resources. We also find that the active predator does not favor patches with more algae and that prey, when with an active predator, continue to favor these higher resource patches. These results suggest that the hunting modes of predators impact their spatial distributions and the spatial distributions of their prey, which has potential to have cascading effects on lower trophic levels.     

Assimilation of carbon and nitrogen from pollen and nectar by a predaceous larva and its effects on growth and development

Abstract. 1. Predaceous insects may benefit from feeding on non‐prey foods, such as pollen, nectar, and honeydew, because they can provide nutrients that help maintain metabolism and enhance overall nutrient intake. Yet, the extent to which predaceous insects can assimilate non‐prey food and the importance of diet mixing during particular life history stages is poorly understood. In this study the relative contribution of an omnivorous diet to the growth and survivorship of a predaceous larva was tested in a hypothetical situation in which nutritionally optimal prey was not available. The study system comprised a predaceous larva (second‐ and third‐instar larvae of the green lacewing Chrysoperla carnea), nutritionally poor prey (larvae of Drosophila melanogaster), and non‐prey food (pollen suspension, a mixture of bee pollen and artificial nectar (1 M sucrose solution)). Chrysoperla carnea larvae in the mixed diet treatment were provided with both Drosophila larvae and pollen suspension, while those reared on the prey and non‐prey diet treatments received only Drosophila larvae or pollen suspension respectively. 2. The inclusion of pollen and sucrose in their diet enhanced the growth of C. carnea larvae. Second instars reared on the mixed diet developed significantly faster than their cohorts reared on the prey diet, however third instars reared on the mixed diet did not develop faster than their cohorts reared on the prey diet. Larvae reared on the mixed diet became larger adults than did those reared on either the prey or non‐prey diets. Third instars reared on the non‐prey diet completed their development while second instars in the non‐prey diet treatment failed to pupate. 3. Stable isotope analysis indicated that the larvae obtained most of their carbon (55–73%) and nitrogen (71–73%) from Drosophila but acquired only a minor amount of carbon (2–5%) and nitrogen (3–11%) from pollen. Larvae reared on the mixed and non‐prey diets acquired a relatively significant amount of carbon (23–51%) from sucrose. 4. A model, which included a novel fractionation factor to account for the isotopic effect of metamorphosis, was developed to explain the proportion of larval growth attributable to each diet item. It explained the adult δ¹³C values to within 0.2‰ and adult δ¹⁵N values to within 0.7‰ in all treatments. 5. Adults fed ¹⁵N‐labelled pollen as larvae retained the ¹⁵N signal of the pollen as adults. 6. The collective results of this study support the view that, despite their dependence on prey arthropods to obtain most of their dietary nitrogen, omnivorous lacewing larvae can enhance their growth and development by supplementing their diets with alternative non‐prey food resources. This finding is consistent with the notion that omnivory has evolved as a feeding strategy to acquire both additional nitrogen as well as trace nutrients.     

Temporal variation in behavioral responses to dietary cues from a gape‐limited predator in tadpole prey: A test of the phylogenetic relatedness hypothesis

The ability of prey to recognize and adequately respond to predators determines their survival. Predator‐borne, post‐digestion dietary cues represent essential information for prey about the identity and the level of risk posed by predators. The phylogenetic relatedness hypothesis posits that prey should respond strongly to dietary cues from closely related heterospecifics but respond weakly to such cues from distantly related prey, following a hierarchical pattern. While such responses have mostly been observed in prey at their first encounter with predators, whether prey maintain such hierarchical levels of investment through time remains unclear. We investigated this question by exposing Rhacophorus arboreus tadpoles to the non‐consumptive effect of gape‐limited newt predators Cynops pyrrhogaster that were fed one of five prey diets across a gradient of phylogenetic relatedness: frog tadpoles (Rhacophorus arboreus, Rhacophorus schlegelii, Pelophylax nigromaculatus, and Hyla japonica) and medaka fish (Oryzias latipes). Predators’ diet, time, and their interaction significantly influenced tadpole activity level. We found support for the phylogenetic relatedness hypothesis: Investments in defense were stronger to cues from tadpole diets than to cues from fish diet. However, such a hierarchical response was recorded only in the first four days following predator exposure, then gradually disappear by day 8 on which the tadpoles exhibited similar activity level across all predator treatments. The findings suggest that, at least under the threat of gape‐limited predators, prey use phylogenetic information to evaluate risk and appropriately invest in defense during early encounters with predators; however, energy requirements may prevent prey from maintaining a high level of defense over long exposure to predation risk.     

Chemosensory responses of Aporcelaimellus nivalis (Nematoda: Dorylaimida) towards kairomones emitted by prey nematodes belonging to different trophic groups

Abstract

Observations were made on the attraction of Aporcelaimellus nivalis towards kairomones/attractants emitted by prey nematodes belonging to different trophic categories, viz., saprophagous, epidermal, migratory semi-endodermal, predatory nematodes, virus vectors and cortical feeders. Aporcelaimellus nivalis responded positively and significantly to prey kairomones, but showed variation in their individual behaviour. Predators are most attracted towards epidermal feeders and least attracted to virus vectors. The differential responses of A. nivalis towards different prey were attributed to the inert behaviour of predators, their preference for a particular species of prey, chemical composition, concentration, quality, quantity of prey attractant, formation of minimum perceptible attraction gradient of prey and minimum response threshold of predators. Various factors such as prey density, period of prey incubation, starvation of predators, temperature, agar concentration, agar thickness and distance of predators from the source of attraction (prey) govern chemosensory responses of predator. Aporcelaimellus nivalis maximum response was towards Hirschmanniella oryzae, when tested as 10 day starved predators in agar plates containing 2 mm thick layer of 1% water-agar with 200 prey individuals previously incubated for 16 h at 30°C. Prey kairomones were most attractive when A. nivalis were tested from a distance of 2 and 3 cm.     

Preference and consumption of Macrolophus pygmaeus preying on mixed instar assemblages of Myzus persicae

This study examines the effects of changes in the prey frequency and abundance on prey selection among the four instars of Myzus persicae by the predator Macrolophus pygmaeus under laboratory conditions. The central hypothesis was that M. pygmaeus will become more selective as prey density increases. It was also observed that M. pygmaeus can occasionally abandon a prey item that had already been killed (non-consumptive prey mortality). It was assumed that the frequency of this behavior would increase with the prey size and prey density. For these purposes prey selection was evaluated by simultaneously presenting all instars of M. persicae to the predator in equal proportions and at increasing densities. M. pygmaeus showed a higher predation rate and a higher preference for smaller prey instars at all prey densities. However, if the predation rate by the predator is expressed in terms of biomass consumed, then biomass gain was higher when feeding on the larger instars of M. persicae. The prey selectivity was indicated by the total prey mortality (consumptive plus non-consumptive prey mortality) as well as by the non-consumptive prey mortality, was associated with relatively high prey densities, depending on the prey instar. Therefore, we argued that the predatory impact of M. pygmaeus on the various instars of the aphid depends not only on prey traits but also on their relative abundance in a patch. Observed decreases in biomass gain from larger prey were likely the result of high prey availability at densities before saturation, which might have caused confusion in the predator’s prey selection.     

Experience affects performance of ten-spined sticklebacks foraging on zooplankton

To study the effects of short-term experience on prey size-selection ten-spined sticklebacks (Pungitius pungitius) were fed 7–13 days with five differing diets of novel prey, Daphnia magna. The diets consisted either of a mixture of two prey size classes (1.7 and 2.2 mm) or of single-sized (1.7 and 2.2 mm) prey. Before and after the diets, the sticklebacks' prey size selection was tested with a 1:1 ratio of 1.7 and 2.2 mm D. magna. Sticklebacks made more attempts to capture large than small prey, but their foraging success was better for small than for large prey. Sticklebacks fed with a diet of both prey sizes chose significantly more large prey on the 13th day than on the 7th day or at the beginning of the experiment. Handling times for both Daphnia size classes decreased slightly with increasing foraging experience. Inexperienced sticklebacks made more unsuccessful strikes on large prey than did experienced fish. Foraging success on large prey improved somewhat with increasing experience in all but one diet group. The results indicate that experience affected ten-spined sticklebacks' prey selection.     

A relationship of diet to prey abundance and the foraging behavior of Trematomus bernacchii

Little information is available regarding fish diets in Antarctica and how they relate to prey availability. The primary objective of this work was to describe the diet of Trematomus bernacchii. The second objective was to compare prey taken with prey present in the benthos along a spatial gradient of prey abundance using Ivlev's Index of Electivity. All samples were collected from 4 different sites on the east side of McMurdo Sound, Antarctica. Fish were captured by divers at the same depth at each site and their stomachs were flushed for dietary analysis. The diet of T. bernacchii varied among sites, and prey selectivity varied inversely with prey abundance. Many of the prey taken by T. bernacchii were sedentary species suggesting that T. bernacchii is a hunt and peck predator.     

The foraging ecology of sympatric marine fish in the genus Embiotoca (Embiotocidae): Importance of foraging behavior in prey size selection

Summary Two locally sympatric temperate marine reef fishes, Embiotoca jacksoni and E. lateralis (Embiotocidae), have high taxonomic similarity in diets. Subdivision of gammarid amphipods, their principal prey, was found. E. jacksoni took more tubicolous gammarid amphipods whereas E. lateralis consumed mostly free-living individuals. The species differed considerably with respect to between-individual variability in taxonomic compositions of their diets. Each E. jacksoni closely resembled other conspecifics in this regard while individual E. lateralis displayed very high between-fish variation. The principal interspecific difference in fish diets concerned the sizes of prey items taken. E. jacksoni ate small but very common items and the mean prey weight in their guts did not differ from random collections of available prey. E. lateralis concentrated on large, rarer sizes such that the average prey weight in their guts was much heavier than available or in the diet of E. jacksoni of the same length. Disparate foraging behaviors was a much better indicator of the relative differences in diets of these two fishes than was external fish morphology. E. jacksoni, which can winnow prey items from unwanted debris, was a relatively indiscriminant forager. E. lateralis did not winnow but actively searched for prey. This species was a much more discriminating forager, but displayed much variability in foraging behavior.     

Extraordinary Predation by the Neotropical Army Ant Cheliomyrmex andicola: Implications for the Evolution of the Army Ant Syndrome1

Workers of the genus Cheliomyrmex are unique among the New world army ants (subfamily Ecitoninae) in that their mandibles are armed with elongate, spine‐like teeth. We present the first prey records for this genus. Cheliomyrmex andicola prey on large‐bodied ground dwelling invertebrates and, possibly, on vertebrates. Unlike other army ants, C. andicola workers use their sting during prey capture. The workers' unusual mandibles and potent stings may be adapted for piercing and gripping the integument of nonarthropod prey animals, and for rapidly subduing large‐bodied prey, respectively. The genus Cheliomyrmex may be the sister taxon to other Neotropical army ants (Ecitoninae), and Cheliomyrmex shares features of mandibular morphology and prey selection with Old World driver ants in the genus Dorylus. Mass cooperative foraging, an important element of army ant behavior, may have arisen in part as an adaptation for exploiting large‐bodied prey.     

Prey selection by a stonefly: the influence of hunger and prey size

Summary The influences of hunger and prey size on prey selection by the stonefly Hesperoperla pacifica (Perlidae) were explored in the laboratory by observing behavioral responses toward ten prey taxa and three nonprey taxa. Patterns of behavior were consistent with most assumptions and predictions of optimal foraging theory predicting sizebased prey selection by pursuing predators. Handling time appeared to increase as an exponential function of prey mass, and prey profitability (mg/s) was highest for small and intermediate-sized prey. Fasted stoneflies consumed a wide range of prey sizes, whereas well-fed stoneflies concentrated their attacks on intermediate-sized prey. Responses of H. pacifica to nonprey taxa, however, suggest that prey recognition and selection are not based on size alone.     

Analysis of the aggregation behavior in the larvae ofHarmonia axyridis Pallas (Coleoptera: Coccinellidae) to prey colony

Summary The searching and handling behaviors ofHarmonia axyridis larvae to the colony ofRhopalosiphum padi were experimentally examined and the processes of their aggregation to the prey colony was analyzed. All the instar larvae searched for the prey at random and they have no preference to the prey colony, but except the 1st instar they tend to aggregate to the plants with prey colonies. The 1st instar larvae tend to stay on the plants they once located. The 2nd to 4th instar larvae often emigrate from the plants without prey colony but seldom emigrate from the plants with prey colonies, and consequently, they aggregate to the plants with prey colonies. The expense of time to eat prey (in the 2nd and 3rd instars) and the change of searching behavior for the prey after feeding (in the 3rd and 4th instars) are responsible for the larval concentration to prey colony as a trapping effect for predators to prey colony.     

How many can you catch? Factors influencing the occurrence of multi-prey loading in provisioning Greater Crested Terns§

Seabirds use several methods to transport food to their chicks; most species carry food in their stomachs or crops, but some terns and auks carry prey in their bills. Terns usually only carry one prey item at a time, limiting the rate at which they can provision their chicks, and restricting their effective foraging range. However, some terns do occasionally carry multiple prey, which should offer a selective advantage, but there are very few studies investigating the factors influencing the occurrence of multi-prey loading. We investigated the occurrence of multi-prey loads in provisioning Greater Crested Terns (Swift Tern) Thalasseus bergii bergii breeding on Robben Island, South Africa. Of 24 173 loads photographed, 1.3% comprised multiple prey items. Up to 11 fish were carried at once, but most multi-prey loads contained two Anchovies Engraulis encrasicolus, the most common prey item for this population of terns. Mixed species prey were recorded for the first time in a tern. Multi-prey loads occurred more frequently during mid- and late-provisioning, presumably because large chicks can cope with multiple prey, and have higher energetic requirements than small chicks. Mean standard length of Anchovies in multi-prey prey loads was less than Anchovies in single loads, possibly suggesting terns compensate for smaller prey sizes by bringing multiple prey back to their chick. The orientation of multiple Anchovies in a tern’s bill tended to be the same, suggesting that they were captured from polarised fish schools. At least some multi-prey loads were caught in a single dive.