Christoph Grüter

Christoph Grüter
University of Bristol | UB · School of Biological Sciences

Doctor of Philosophy

About

103
Publications
18,665
Reads
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2,684
Citations
Additional affiliations
October 2015 - January 2020
Johannes Gutenberg-Universität Mainz
Position
  • Professor (Assistant)
October 2013 - September 2015
University of Lausanne
Position
  • Group Leader
August 2012 - September 2013
University of São Paulo
Position
  • PostDoc Position

Publications

Publications (103)
Article
Full-text available
Stingless bees are the most species-rich group of eusocial bees and show great diversity in behaviour, ecology, nest architecture, colony size, and worker morphology. How this variation relates to varying selection pressures and constraints is not well understood. Variation can be caused by selection acting on behavioural or morphological traits, b...
Preprint
Full-text available
Many bee species show flower constancy, i.e . a tendency to visit flowers of one type during a foraging trip. Flower constancy is important for plant reproduction, but whether bees also benefit from flower constancy remains unclear. Social bees, which often use communication about food sources, show particularly strong flower constancy. We hypothes...
Preprint
Full-text available
How behavior in insect societies is regulated remains a fundamental question in sociobiology. In hymenopteran societies, the queen plays a crucial role in regulating group behavior by affecting individual behavior, physiology, and lifespan through worker gene expression. Honey bee ( Apis mellifera ) queens signal their presence via the queen mandib...
Preprint
Full-text available
Animals can acquire information through individual learning or by copying others. Simulations suggest that social learning is expected to lead to better rewards, but experimental studies confirming this remain scarce. We tested how a well-known form of social learning in ants, tandem running, affects individual foraging success of Temnothroax nylan...
Preprint
Full-text available
Eusocial insects have evolved different strategies to share information about their environment and workers can recruit nestmates to food sources or new nest sites. Ants are the most species-rich social insect group and are known to use pheromones, visual and tactile signals to communicate and inform nestmates about resources. However, how these di...
Article
Full-text available
Social information is widely used in the animal kingdom and can be highly adaptive. In social insects, foragers can use social information to find food, avoid danger or choose a new nest site. Copying others allows individuals to obtain information without having to sample the environment. When foragers communicate information they will often only...
Article
Social animals often share information about the location of resources, such as a food source or a new nest-site. One well-studied communication strategy in ants is tandem running, whereby a leader guides a recruit to a resource. Tandem running is considered an example of animal teaching because a leader adjusts her behaviour and invests time to he...
Article
Full-text available
Tropical ants experience intense intra- and interspecific competition for food sources, which influences their activity pattern and foraging strategies. Even though different ant species can coexist through spatial and temporal niche partitioning, direct competition for food cannot be avoided. Recruitment communication is assumed to help colonies t...
Article
Full-text available
Communication is essential for social animals, but deciding how to utilize information provided by conspecifics is a complex process that depends on environmental and intrinsic factors. Honey bees use a unique form of communication, the waggle dance, to inform nestmates about the location of food sources. However, as in many other animals, experien...
Article
Full-text available
Diversity in animal groups is often assumed to increase group performance. In insect colonies, genetic, behavioural and morphological variation among workers can improve colony functioning and resilience. However, it has been hypothesized that during communication processes, differences between workers, e.g. in body size, could also have negative e...
Article
Full-text available
Foraging behaviour is crucial for the development of a honeybee colony. Biogenic amines are key mediators of learning and the transition from in‐hive tasks to foraging. Bees that have become foragers vary considerably in their behavior, but whether and how this behavioral diversity depends on biogenic amines is not yet well understood. For example,...
Preprint
Full-text available
Communication is essential for social animals, but deciding how to utilize information provided by conspecifics is a complex process that depends on environmental and intrinsic factors. Honey bees use a unique form of communication, the waggle dance, to inform nestmates about the location of food sources. However, as in many other animals, experien...
Chapter
In his famous “pin factory” example, Adam Smith (1776) calculated that a group of labourers with division of labour could produce at least 240 times more pins per day than a group of labourers without division of labour. He attributed this massive increase in productivity to several factors. Firstly, division of labour results in workers becoming m...
Chapter
The tropics and subtropics are home to thousands of different types of bees. One bee group that frequently calls an observer’s attention are the stingless bees or Meliponini. In the Neotropics, for example, about half of all bees that one is likely to see on flowers belongs to this group (Chap. 9). Stingless bees can be smaller than a fruit fly or...
Chapter
Finding a good food source can be challenging for a bee, especially if she is on her own. This task can be greatly simplified if a nestmate tells her how and where to find a good food source. Information from nestmates is probably even more important during swarming when large numbers of bees need to find the way from their old to the new nest site...
Chapter
More than 90% of all tropical flowering plants (Angiosperms) are pollinated by animals (Ollerton et al. 2011). Bees represent the most significant group of pollinators in both new and old world tropics (Bawa 1990; Momose et al. 1998; Corlett 2004; Klein et al. 2007; Michener 2007; Giannini et al. 2015; Ollerton 2017) and among them, stingless bees...
Chapter
Stingless bee nests contain valuable resources, such as honey, pollen, cerumen, batumen, resin, larval food and finally, the cavity and the bees themselves (Chap. 3). It is, therefore, unsurprising that other animals attempt to gain access to these resources. This, in turn, can lead to substantial predation-related mortality of stingless bee coloni...
Chapter
Stingless bees need different types of resources to rear brood, build nest structures and defend their colony. This has major consequences for tropical ecosystems because the collection of pollen, the main protein source for larvae, and carbohydrates in the form of floral nectars lead to pollination. Worldwide, thousands of plant species are likely...
Chapter
Stingless bee brood rearing is a complex process that involves workers performing a number of different jobs and requires coordination with the queen. After a new brood cell is finished, several workers regurgitate larval food into this cell, a process called mass provisioning. Shortly afterwards, the queen lays her egg on top of the larval food, i...
Chapter
Stingless bees (Meliponini) belong to the corbiculate bees, a monophyletic group of bees characterised, among other things, by their particular pollen-carrying structures (“pollen baskets” or corbiculae) on the hind legs (Chap. 1; Fig. 1.1) (Michener 2007). The evolution of the concave pollen baskets allowed corbiculate bees to transport large amou...
Chapter
To start a new colony, stingless bee queens need the help of workers. The first tasks of these workers are finding and inspecting potential nest sites, building nest-structures at the selected site, gathering food and defending the new home. Most details of this process are still poorly understood and there has been little research on stingless bee...
Chapter
The nest is the place where bees spend most of their time. Only towards the end of a worker’s life will she start to leave the nest regularly to forage for resources or guard the nest entrance (Chaps. 6 and 8). In the complete darkness of the nest cavity, bees are in frequent contact with nest-mates, share food and exchange chemical and tactile inf...
Article
Regulation of pollen and nectar foraging in honeybees is linked to differences in the sensitivity to the reward. Octopamine (OA) participates in the processing of reward-related information in the bee brain, being a candidate to mediate and modulate the division of labour among pollen and nectar foragers. Here we tested the hypothesis that OA affec...
Preprint
Full-text available
This work describe an algorithm for the automatic analysis of the waggle dance of honeybees. The algorithm analyses a video of a beehive with 13,624 frames, acquired at 25 frames/second. The algorithm employs the following traditional image processing steps: conversion to grayscale, low pass filtering, background subtraction, thresholding, tracking...
Article
Honeybees can be directed to profitable food sources by following waggle dances performed by other bees. Followers can often choose between using this social information or relying on memories about food sources they have visited in the past, so-called private information. While the circumstances that favour the use of either social or private info...
Preprint
Full-text available
Social animals often share information about the location of resources, such as a food source or a new nest-site. One well-studied communication strategy in ants is tandem running, whereby a leader guides a recruit to a resource. Tandem running is considered an example of animal teaching because a leader adjusts her behaviour and invests time to he...
Article
• The tropical stingless bees have evolved intricate communication systems to recruit nestmates to food locations. Some species are able to accurately communicate the location of food, whereas others simply announce the presence of food in the environment. • Plebeia droryana is a tiny Neotropical stingless bee that, until recently, was thought to...
Article
Full-text available
The biogenic amine octopamine (OA) is a key modulator of individual and social behaviours in honeybees, but its role in the other group of highly eusocial bees, the stingless bees, remains largely unknown. In honeybees, OA mediates reward perception and affects a wide range of reward-seeking behaviours. Thus, we tested the hypothesis that OA increa...
Book
Stingless bees (Meliponini) are the largest and most diverse group of social bees, yet their largely tropical distribution means that they are less studied than their relatives, the bumble bees and honey bees. Stingless bees produce honey and collect pollen from tens of thousands of tropical plant species and, in the process, provide critical polli...
Preprint
Full-text available
Diversity in animal groups is often assumed to increase group performance. In insect colonies, genetic, behavioral and morphological variation among workers can improve colony functioning and resilience. However, it has been hypothesized that during communication processes, differences between workers, e.g. in body size, could also have negative ef...
Article
Full-text available
Plants and pollinators form beneficial relationships, with plants offering resources in return for pollination services. Some plants, however, add compounds to nectar to manipulate pollinators. Caffeine is a secondary plant metabolite found in some nectars that affects foraging in pollinators. In honeybees, caffeine increases foraging and recruitme...
Article
Task allocation is a central challenge of collective behavior in a variety of group-living species, and this is particularly the case for the allocation of social insect workers for group defense. In social insects, both benefits and considerable costs are associated with the production of specialized soldiers. We asked whether colonies mitigate co...
Article
Communication is the foundation of all social systems, and learning is perhaps the most important cognitive tool. But how do these two critical faculties interact? With social insects being some of the best learners of the invertebrate world, and indisputably the most communicative, we examine the role of learning and experience in social insect co...
Article
Full-text available
Division of labor plays a fundamental role in colony organization in social insects. In many species, division of labor is based on temporal behavioral castes, whereby workers change tasks as they age. However, division of labor remains relatively poorly understood in the large and diverse group of stingless bees (Meliponini), particularly in the l...
Article
Full-text available
Honeybees use the waggle dance to share information about food-site locations with nestmates. However, the importance of this behavior in colony foraging success remains unclear. We tested whether spatial dance information affects colony foraging success in a human-modified temperate environment by comparing colonies with oriented and disoriented d...
Article
Insect societies face many social parasites that exploit their altruistic behaviours or their resources. Due to the fitness costs these social parasites incur, hosts have evolved various behavioural, chemical, architectural and morphological defence traits. Similar to bacteria infecting multicellular hosts, social parasites have to successfully go...
Article
Full-text available
Social insect colonies exploit food sources that vary in their profitability and riskiness. One factor that affects both profitability and riskiness is the foraging distance: more distant resources are both more costly to exploit and expose individuals to greater predation or navigational risks. Temnothorax nylanderi scouts use tandem running to re...
Article
Full-text available
Tandem running is a common recruitment strategy in ant species with small colony sizes. During a tandem run, an informed leader guides a usually naïve nestmate to a food source or a nest site. Some species perform tandem runs only during house hunting, suggesting that tandem running does not always improve foraging success in species known to use t...
Article
Full-text available
The differentiation of workers into morphological castes represents an important evolutionary innovation that is thought to improve division of labor in insect societies. Given the potential benefits of task-related worker differentiation, it is puzzling that physical worker castes, such as soldiers, are extremely rare in social bees and absent in...
Article
Full-text available
Many ant and termite colonies are defended by soldiers with powerful mandibles or chemical weaponry. Recently, it was reported that several stingless bee species also have soldiers for colony defence. These soldiers are larger than foragers, but otherwise lack obvious morphological adaptations for defence. Thus, how these soldiers improve colony fi...
Article
Full-text available
The communication involved in the foraging behaviour of social insects is integral to their success. Many ant species use trail pheromones to make decisions about where to forage. The strong positive feedback caused by the trail pheromone is thought to create a decision between two or more options. When the two options are of identical quality, thi...
Article
Workers in many eusocial insect species show considerable size variation within a colony. Honeybees (Apis mellifera) vary little in size compared to other eusocial bee species, but there is evidence for a link between worker size and behaviour. In this study, we investigated how size variation and the average size of honeybee foragers change during...
Article
Full-text available
Learning plays an important role in the life of many animals. In social insects, colony foraging success depends on the combined actions of many individuals and learning contributes to individual foraging success. In many ants, for example, route learning helps foragers to navigate between the nest and a food source. Here, we studied if the foragin...
Article
Social insect colonies function as highly integrated units despite consisting of many individuals. This requires the different functional parts of the colony (e.g. different castes) to exchange information that aid in colony functioning and ontogeny. Here we discuss inter-caste communication in three contexts, firstly, the communication between mal...
Article
Full-text available
Many colonial animals rely for their defense on a soldier caste. Adaptive colony demography theory predicts that colonies should flxibly adjust the investment in different worker castes depending on the colony needs. For example, colonies should invest more in defensive workers (e.g., soldiers) in dangerous environments. However, evidence for this...
Article
Full-text available
Bees are well known for being industrious pollinators. Some species, however, have taken to invading the nests of other colonies to steal food, nest material or the nest site itself. Despite the potential mortality costs due to fighting with an aggressive opponent, the prospects of a large bounty can be worth the risk. In this review, we aim to bri...
Article
Full-text available
The differentiation of workers into morphological subcastes (e.g., soldiers) represents an important evolutionary transition and is thought to improve division of labor in social insects. Soldiers occur in many ant and termite species, where they make up a small proportion of the workforce. A common assumption of worker caste evolution is that sold...
Article
Full-text available
Honey bees (Apis sp.) are the only known bee genus that uses nest-based communication to provide nest-mates with information about the location of resources, the so-called “dance language.” Successful foragers perform waggle dances for high quality food sources and, when swarming, suitable nest-sites. However, since many species of social insects d...
Article
Full-text available
Many ants forage in complex environments and use a combination of trail pheromone information and route memory to navigate between food sources and the nest. Previous research has shown that foraging routes differ in how easily they are learned. In particular, it is easier to learn feeding locations that are reached by repeating (e.g. left–left or...
Article
Full-text available
The spectacular morphological variation among workers of certain ant and termite species has fascinated evolutionary biologists since Darwin. In some species, environmental triggers induce larvae to develop into different phenotypes, e.g. minor or major workers (soldiers). Recently, the first soldier subcaste was discovered in a bee, the stingless...
Article
Trail pheromones do more than simply guide social insect workers from point A to point B. Recent research has revealed additional ways in which they help to regulate colony foraging, often via positive and negative feedback processes that influence the exploitation of the different resources that a colony has knowledge of. Trail pheromones are ofte...
Article
Full-text available
Waggle dancing bees provide nestmates with spatial information about high quality resources. Surprisingly, attempts to quantify the benefits of this encoded spatial information have failed to find positive effects on colony foraging success under many ecological circumstances. Experimental designs have often involved measuring the foraging success...
Article
Full-text available
Copying others can greatly improve individual fitness and is fundamental for the organisation of societies. Yet in some situations it is better to ignore social information and either explore the world individually or use personal information obtained through prior experience. Insects provide excellent models to study the strategic use of social in...
Article
Full-text available
Social insects often respond to signals and cues from nest-mates, and these responses may include changes in the information they, in turn, transmit. During foraging, Lasius niger deposits a pheromone trail to recruit nestmates, and ants that experience trail crowding deposit pheromone less often. Less studied, however, is the time taken for signal...
Article
Full-text available
Individual honeybee foragers often need to decide between using private versus social information when choosing where to forage. Social information is provided by the waggle dances made by successful foragers. Experienced foragers also have private information about the feeding sites they have previously visited. Previous work has shown that honeyb...
Article
Full-text available
Returning honey bee foragers perform waggle dances to inform nestmate foragers about the presence, location and odour of profitable food sources and new nest sites. The aim of this study is to investigate how the characteristics of waggle dances for natural food sources and environmental factors affect dance follower behaviour. Because food source...
Article
Full-text available
Crowding in human transport networks reduces efficiency. Efficiency can be increased by appropriate control mechanisms, which are often imposed externally. Ant colonies also have distribution networks to feeding sites outside the nest and can experience crowding. However, ants do not have external controllers or leaders. Here, we report a self-orga...
Article
Full-text available
In beekeeping, queen honey bees are often temporarily kept alive in cages. We determined the survival of newly-emerged virgin honey bee queens every day for seven days in an experiment that simultaneously investigated three factors: queen cage type (wooden three-hole or plastic), attendant workers (present or absent) and food type (sugar candy, hon...
Article
Full-text available
Ants are central place foragers and use multiple information sources to navigate between the nest and feeding sites. Individual ants rapidly learn a route, and often prioritize memory over pheromone trails when tested on a simple trail with a single bifurcation. However, in nature ants often forage at locations which are reached via more complex ro...
Article
Full-text available
Positive feedback plays a major role in the emergence of many collective animal behaviours. In many ants pheromone trails recruit and direct nestmate foragers to food sources. The strong positive feedback caused by trail pheromones allows fast collective responses but can compromise flexibility. Previous laboratory experiments have shown that when...
Data
The raw data for the tests presented in Table 2 . (XLSX)
Data
Smallest colony size still showing flexibility under high crowding conditions (8 vs. 24 agents). Proportions of agents foraging at the two food patches, in which the second patch (red line) allowed three times as many agents to feed simultaneously but was made available 900 times steps after agents started foraging at the first food patch (blue lin...
Data
Photo showing the feeder (petri-dish, 5 cm diameter) standing on 2 cm wooden legs. The feeder contained 1 M sucrose solution. Ants could gain access to the solution via 1 mm feeding holes (27 in this situation). (TIF)
Data
Colony size needed for flexibility under low crowding conditions (72 vs. 216 agents). Proportions of agents foraging at the two food patches, in which the second patch (red line) allowed three times as many agents to feed simultaneously but was made available 900 times steps after agents started foraging at the first food patch (blue line). Data av...
Data
The NetLogo computer code of the agent-based simulation model. The file extension “.txt” can be renamed to “.nlogo” to open the file. (TXT)
Data
Model 1 with the different behavioural states being updated in reversed sequence (unloading agents→recruiting agents→dissatisfied agents→feeding agents→foraging agents→idle agents). Proportions of agents visiting two identical food patches each with space for 8, 24, 72 or 216 foraging agents. The blue line represents the patch that had more agents...
Data
The effect of the arm length on flexibility under high crowding conditions (8 vs. 24 agents). Proportions of agents foraging at the two food patches, in which the second patch (red line) allowed three times as many agents to feed simultaneously but was made available 1800 time steps after agents started foraging at the first food patch (blue line)....
Data
The effect of the main branch length on flexibility under high crowding conditions (8 vs. 24 agents). Proportions of agents foraging at the two food patches, in which the second patch (red line) allowed three times as many agents to feed simultaneously but was made available 14000 time steps after agents started foraging at the first food patch (bl...
Data
The effect of the probability of dissatisfied agents to walk to the nest versus to the second feeder on collective flexibility under high crowding conditions (8 vs. 24 agents). Proportions of agents foraging at the two food patches, in which the second patch (red line) allowed three times as many agents to feed simultaneously but was made available...
Article
Full-text available
Division of labor among workers is common in insect societies and is thought to be important in their ecological success. In most species, division of labor is based on age (temporal castes), but workers in some ants and termites show morphological specialization for particular tasks (physical castes). Large-headed soldier ants and termites are wel...