The evolution of obligate kleptoparasitism, the theft of food, has led to remarkable innovations, including physical weapons and chemical signals that can evolve into chemical weapons. Stingless bees ...in the genus
Lestrimelitta
are excellent examples of this phenomenon because they are obligate kleptoparasites that no longer collect floral resources and instead steal brood resources from other bees. Their ability to raid successfully is thus essential to their fitness even when they fight species that are physically bigger, have larger defense forces, or both. We conducted morphometric analyses, quantified
Lestrimelitta niitkib
mandibular gland pheromone (MGP) components, and carried out individual fighting trials between
L. niitkib
and the stingless bee
Scaptotrigona mexicana
, a common victim species, to shed light on the detailed reasons for their success at robbing. Measurements showed that
L. niitkib
mandibles have thicker exoskeleton cuticles and overall greater width, particularly in the medial and proximal sections, than S
. mexicana
, which is quite similar in body size. In all fights,
L. niitkib
bit victims and released MGP, as it does during raids.
Scaptotrigona mexicana
victims exhibited significantly increased uncoordinated behaviors and showed partial or complete paralysis. We analyzed and quantified the major components of MGP, which consisted of large quantities of geranial (mean of 253 μg) and neral (48 μg) per bee. Microinjections of 1 bee equivalent (BE) of natural or synthetic MGP and ≥ 0.1 BE of geranial significantly increased deleterious behaviors and paralysis as compared to control injections. We suggest that the large quantities of MGP used during raiding have led to an unexpected outcome, a semiochemical evolving the additional function of a toxin, and contribute to the ability of
Lestrimelitta
to rob its victims.
Significance statement
Kleptoparasites, organisms that steal food resources, employ multiple physical and chemical tools to survive. The success of kleptoparasitism requires a balance between honesty and coercion in interspecific communication. The genus
Lestrimellita
consists of a group of kleptoparasitic stingless bee species that raid other bee colonies for food and therefore depend upon winning these raids. However, why they succeed remains not fully understood. We studied differences in morphology between
L. niitkib
and its victims, the pheromones they release during raids, and ran individual fight trials between
L. niitkib
and a common victim to identify why they are successful. We suggest that the release of pheromones at the beginning of raids, in concert with the pheromone’s toxicity, has been combined to improve
L. niitkib
’s ability to successfully rob.
Context
Habitat loss and alteration affect wildlife populations worldwide. Bush encroachment alters landscapes and threatens arid and semi-arid grasslands, but its effects on predator–prey ...relationships and carnivore community ecology are not well understood. Predation strategies of large predators, for example high-speed pursuits versus ambush from short distances, are likely to be affected differently by bush encroachment.
Objectives
We assessed how bush encroachment affects overall predation success of cheetahs (
Acinonyx jubatus
) and leopards (
Panthera pardus
) in a savanna landscape under variable fractional woody cover (FWC). We tested if predation success remained relatively unchanged for leopards across a gradient of FWC, and whether cheetah predation was most successful at low to intermediate cover and varied seasonally.
Methods
Belly scores of predators were measured from camera-trap images collected over 7 years in north-central Namibia and used to index predation success. We derived predicted belly score probabilities as a function of FWC, which was measured using a Synthetic Aperture Radar (SAR)-derived satellite data layer.
Results
Predicted leopard predation success was highest at 0.27–0.34 FWC in the dry season, potentially due to lower prey density in highly covered areas and decreased prey catchability in low cover. Predicted cheetah predation success was highest at 0.24–0.28 FWC in the wet season, potentially due to increased landscape openness, high availability of habitat margins for visualising and stalking prey, and decreased kleptoparasitism by leopards. These results highlight optimal habitat cover thresholds that favour lower FWC for cheetah than for leopard.
Conclusions
The findings indicate that landscape heterogeneity is important for predation success of cheetahs and leopards, suggesting that habitat management should focus on bush control efforts to maintain intermediate levels of bush cover.
Artificial feeding of wildlife is a widespread, but controversial, management practice with many positive and negative effects. Besides the effects on the target species, it can also affect other ...(non-target) species by modulating interspecific interactions. Previous research showed that the presence of artificial feeding sites for bears and ungulates increases the risk of kleptoparasitism by the brown bear (Ursus arctos) on kills made by Eurasian lynx (Lynx lynx). However, it remains unknown whether lynx adjust their behaviour to the distribution of artificial feeding sites, which also attract potential prey (ungulates) for lynx. Using GPS telemetry data, we explored the spatiotemporal lynx response to such sites and studied how this response varied with experience level, i.e. between adult resident individuals ('experienced lynx') and juveniles and/or translocated individuals ('naïve lynx'). We found that lynx experience played an important role in the use of artificial feeding sites. Specifically, while both experienced and naïve lynx selected feeding sites while moving within their home range, the attraction was stronger among the naïve lynx. Considering the distribution of kill sites, naïve lynx killed prey closer to the artificial feeding sites than expected, while experienced lynx avoided them. Finally, the proximity to artificial feeding sites by experienced lynx showed an annual variation, matching the seasonal kleptoparasitism risk, with overall closer proximity to feeding sites during the winter, when bears are less active, which is also when ungulates are more concentrated around feeding sites. Our study suggests that, despite the relatively recent introduction of artificial feeding in the ecosystems, wildlife can learn to respond to the altered interactions with other species. However, this appears to be a learning process with manifold management and conservation implications. A better understanding of species interactions and space use in the context of resource manipulation is increasingly relevant as the use of anthropogenic food by wildlife is nowadays substantial and widespread across most parts of the world.
Symbiotic relationships in marine environments are not fixed and can change throughout the animal's life. This study investigated the ontogeny of symbiosis of the spider crab Libinia ferreirae with ...the host medusa Lychnorhiza lucerna. We described the type of relationship, the temporal correlation among species, and food habits. More than 50% of the sampled crabs were symbionts, most in early life stages. The highest number of crabs found in a single medusa was 11. Symbiosis was observed throughout most of the year but was more evident in warm periods. The crab has many benefits in this relationship with a medusa. One is the use of food resources captured by the medusa, primarily copepods. Because the crab steals the medusa's food, it is a kleptoparasitic relationship. There is a niche partition between symbiont and the free-living crabs as they occupy different habitats and use nonoverlapping food resources. Previous research reported that symbiosis first developed during the crab's last larval phase (megalopa) when crab and medusa are in the same habitat. Observation of the crab's behavior shows that symbiosis occurs when the crab can grab to the medusa when the host touches the sea bottom. The crab also took advantage of water currents, releasing itself from the substrate and then drifting toward the medusa. The symbiotic relationship that crabs have with the medusa provides then with a nursery, food resources, shelter, dispersion, and decreased competition with free-living adult crabs, all essential for the crab's survival.
Kleptoparasitic spiders live and forage in the webs of other spiders. Using vibratory cues generated by the host spider during prey capture, they leave their resting positions in the upper ...peripheries of the host web and move towards the centre of the web where they feed along with the host spider or steal small pieces of prey. While the triggers for initiating the foraging raids are known, there is little information about the fine-scale trajectory dynamics in this model system. We mapped the movement of the kleptoparasite
Argyrodes elevatus
in the web of the host
Trichonephila clavipes
. We filmed the movement of the kleptoparasite spiders and quantified the trajectory shape, speed, heading directions and path revisitation. Our results show that kleptoparasitic spider movement is spatially structured, with higher levels of speed at the peripheries and slower in the centre of the web. We found a high level of variation in trajectory shapes between individuals. We found that the majority of heading orientations were away from the hub suggesting that detouring or repeated approaches are an essential component of kleptoparasite movement strategies. Our results of the revisitation rate also confirm this pattern, where locations close to the hub were revisited more often than in the periphery. The kleptoparasite–host spider system is a promising model to study fine-scale movement patterns in small bounded spaces.
While the unique hunting behavior of archerfish has received considerable scientific attention, the specific social cues that govern behaviors like intraspecific kleptoparasitism in the species are ...less understood. This paper asks whether the use of a robotic facsimile representing an archerfish can elicit a social response if it approximates an archerfish’s appearance, along with key features of its hunting behavior. We found that the fish respond to the robot when it hunted, as indicated by decreasing distances between the robot and fish (and among the fish) during the robot’s hunting behavior sequence, as well as higher net transfer entropy when the robot was hunting. These effects were present even when the robot’s “hunt” was unproductive and did not result in food. The temporal pattern of fish approach to the robot and each other indicated that the segment of robot hunting behavior proximal to the robotic facsimile shot elicited fish behavior initially. However, earlier cues in the robot’s hunting sequence became important following more experience with a food contingency. This indicates that further studies could use a robotic facsimile to conduct a detailed stimulus analysis, changing aspects of the robot’s appearance and behavior to uncover the basic mechanisms of information transfer among individuals in a social hunting scenario.
Joining a social group entails a range of possible costs and benefits, with the balance of pros and cons potentially dependent on the specific conditions present in the local environment. In the ...third-instar stage of fruit fly (
Drosophila melanogaster
) development, individuals may join together into clusters that can increase access to buried food resources, but this collaboration comes with the possible risks of kleptoparasitism or slowed development. Cluster feeding in
D. melanogaster
larvae has the potential to be a valuable model for studying the dynamics of social and group behaviours, but little is currently known about the plasticity of its expression. In this study, we set out to explore how this collective behaviour might be shaped by the nutritional quality of the environment and/or the spatial distribution of resources by manipulating the nutritional quality of the larval environment and the configuration of available resources. By tracking the timing, frequency, composition, and size of any feeding clusters that subsequently developed, we could better understand the factors that influenced the expression of this social behaviour. We found that cluster expression varied temporally and with the type of resources present in the environment. When possible, larvae formed clusters more frequently to take advantage of otherwise inaccessible resources. The increased clustering patterns were most dramatically manifested as deeper feeding mines. This work expands our understanding of the plastic nature of this collective behaviour, given that discrete environmental changes elicited dynamic changes in larval behaviours.
Examples of predator–prey interactions in which flies rob ants are uncommon. To date, this behavior has only been recorded in the genus Bengalia Robineau‐Desvoidy (Bengaliinae, Diptera, ...Calliphoridae). These predatory flies ambush ants, and rob them of the food or offspring that they are carrying. However, because of the rarity of this behavior, the reasons and consequences (evolutionary advantages) are unknown, and indeed, the behavior has been sometimes considered anecdotal. In this study, we employed field investigations and behavioral analyses to investigate whether the sex of the fly Bengalia varicolor, or the weight and quality of the food carried by Pheidole nodus ants influenced fly–ant interactions in their natural habitats. We show that food weight and quality influenced the behavior of B. varicolor independent of the fly's sex. Robbing behavior by the flies was more successful when the food robbed was of high‐quality and light in weight. Furthermore, the weight of the food robbed modulated the escape distance the flies could carry it. This then may affect the food quality and weight transported by the ants. This is a novel example of deciphering the relationship between highwayman flies and their ant victims. Given the widespread distribution of Bengalia flies, we suggest that such interspecific predator–prey encounters may shape the robbery interactions and the carrying behavior of further ant species in nature.
A B. varicolor individual is robbing a single ant with its food.
Osmia caerulescens is a generalist solitary bee well‐adapted to altered anthropogenic environments, and the kleptoparasitic wasp Sapyga quinquepunctata has been cited among its natural enemies.
We ...analysed offspring characteristics of O. caerulescens and S. quinquepunctata, at population and individual levels, and compared these characteristics between sunny and shady aspects and between two zones within the valley that differed in landscape complexity (simple and complex zones).
The offspring production of O. caerulescens was higher in sunny aspect at population and individual levels while S. quinquepunctata was positively associated with the zone with a lower proportion of agricultural land (complex zone). We did not detect a relationship between number of brood cells parasitised and number of brood cells established by host. Despite the parasitism being higher in the area with favourable characteristics for both species, the reproductive success of O. caerulescens did not show signs of reduction. At the individual level, nests with fewer brood cells were more likely to be parasitised.
Studying the relationship of environmental factors and landscape features at population and individual levels provides a better understanding of how these characteristics could be driving the offspring production of the solitary bee and their ecological interactions.
The offspring investment of Osmia caerulescens rises in the sunny aspect of the valley where its abundance and offspring body size are higher.
The probability of a nest being parasitised by Sapyga quinquepunctata increases in the zone of the valley with higher landscape complexity.
Under advantageous conditions for both species (sunny aspect and complex zone), a greater pressure on host population is exerted by the kleptoparasite, although the offspring production is not reduced.
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