Learning to anticipate mate presence shapes individual sex roles in the hermaphroditic pond snail, Lymnaea stagnalis.

Despite being simultaneously male and female, hermaphrodites may still need to assume the male or female sexual role in a mating encounter, with the option to swap roles afterwards. For the great pond snail, Lymnaea stagnalis, deciding which sexual role to perform has important consequences, since sperm transfer and male reproductive success can be decreased. We hypothesised that detecting cues that indicate a possible mating encounter could help them to adapt their mating behaviour.

Cause, development, function, and evolution: Toward a behavioral ecology of rescue behavior in ants.

In a species of Mediterranean desert-dwelling ant, Cataglyphis piliscapa (formerly, C. cursor), some individuals, mostly foragers, engage in highly orchestrated behavior to free a trapped nestmate. Their behavior, which we have labeled rescue, is a heritable trait in this species, and it appears fully formed within a few days of an ant's emergence as an adult.

Rescue specialists in Cataglyphis piliscapa ants: The nature and development of ant first responders.

Previous research in our laboratories has demonstrated that, within each colony of Cataglyphis piliscapa (formerly C. cursor) ants, only some individuals are capable of performing a complex sequence of behavioral patterns to free trapped nestmates-a sequence that not only is memory-dependent but also is responsive to the particular circumstances of that entrapment and how the rescue operation unfolds. Additionally, this rescue behavior is inherited patrilineally from but a few of the many males that fertilize the eggs of the colony's single queen.

Analysis of ants' rescue behavior reveals heritable specialization for first responders.

In colonies of ants, a single queen mates with multiple males, creating the foundation for heritable behavioral specializations. A novel and unique candidate for such specializations is rescue behavior, a precisely delivered form of altruism in which workers attempt to release trapped nestmates and which relies on short-term memory of previous actions to increase its efficiency. Consistent with task specialization, not all individuals participate; instead, some individuals move away from the victim, which gives rescuers unrestricted access.

Natural aversive learning in Tetramorium ants reveals ability to form a generalizable memory of predators' pit traps.

Many species of ants fall prey to pit-digging larval antlions (Myrmeleon spp.), extremely sedentary predators that wait, nearly motionless at the bottom of their pit traps, for prey to stumble inside. Previous research, both in the field and laboratory, has demonstrated a remarkable ability of these ants to rescue trapped nestmates, thus sabotaging antlions' attempts to capture them.

Organization of rescue behaviour sequences in ants, Cataglyphis cursor, reflects goal-directedness, plasticity and memory.

The experimental study of rescue behaviour in ants, behaviour in which individuals help entrapped nestmates in distress, has revealed that rescuers respond to victims with very precisely targeted behaviour. In Cataglyphis cursor, several different components of rescue behaviour have been observed, demonstrating the complexity of this behaviour, including sand digging and sand transport to excavate the victim, followed by pulling on the victim's limbs as well as the object holding the victim in place, behaviour that serves to free the victim. Although previous work suggested that rescue was optimally organized, first to expose and then to extricate the victim under a variety of differing circumstances, experimental analysis of that organization has been lacking.

Ants and antlions: The impact of ecology, coevolution and learning on an insect predator-prey relationship.

A behavioural ecological approach to the relationship between pit-digging larval antlions and their common prey, ants, provides yet another example of how the specific ecological niche that species inhabit imposes selection pressures leading to unique behavioural adaptations. Antlions rely on multiple strategies to capture prey with a minimal expenditure of energy and extraordinary efficiency while ants employ several different strategies for avoiding capture, including rescue of trapped nestmates. Importantly, both ants and antlions rely heavily on their capacity for learning, a tool that sometimes is overlooked in predator-prey relationships, leading to the implicit assumption that behavioural adaptations are the result of fixed, hard-wired responses.

Rescue of newborn ants by older Cataglyphis cursor adult workers.

Cataglyphis cursor worker ants are capable of highly sophisticated rescue behaviour in which individuals are able to identify what has trapped a nestmate and to direct their behaviour towards that obstacle. Nonetheless, rescue behaviour is constrained by workers' subcaste: whereas foragers, the oldest workers, are able both to give and to receive the most help, the youngest workers, inactives, neither give nor receive any help whatsoever; nurses give and receive intermediate levels of aid, reflecting their intermediate age. Such differences in rescue behaviour across subcastes suggest that age and experience play a critical role.

A Delphi study for the development of an infant skin breakdown risk assessment tool.

Background: Infants, especially those born prematurely, are at increased risk for skin breakdown because of the immaturity and fragility of their skin. Following a review of existing skin risk assessment tools, we concluded that none provided valid, clear, and concise assessment criteria and direction for treatment interventions specifically for use with neonates.

Purpose: To examine the risk factors of skin breakdown in infants using the knowledge of interprofessional providers who routinely care for infants.

Toward a behavioral ecology of rescue behavior.

Although the study of helping behavior has revolutionized the field of behavioral ecology, scientific examination of rescue behavior remains extremely rare, except perhaps in ants, having been described as early as 1874. Nonetheless, recent work in our laboratories has revealed several new patterns of rescue behavior that appear to be much more complex than previously studied forms. This precisely-directed rescue behavior bears a remarkable resemblance to what has been labeled empathy in rats, and thus raises numerous philosophical and theoretical questions: How should rescue behavior (or empathy) be defined? What distinguishes rescue from other forms of altruism? In what ways is rescue behavior in ants different from, and similar to, rescue in other non-human animals? What selection pressures dictate its appearance? In this paper, we review our own experimental studies of rescue in both laboratory and field, which, taken together, begin to reveal some of the behavioral ecological conditions that likely have given rise to rescue behavior in ants.

Division of labor regulates precision rescue behavior in sand-dwelling Cataglyphis cursor ants: to give is to receive.

Division of labor, an adaptation in which individuals specialize in performing tasks necessary to the colony, such as nest defense and foraging, is believed key to eusocial insects' remarkable ecological success. Here we report, for the first time, a completely novel specialization in a eusocial insect, namely the ability of Cataglyphis cursor ants to rescue a trapped nestmate using precisely targeted behavior. Labeled "precision rescue", this behavior involves the ability of rescuers not only to detect what, exactly, holds the victim in place, but also to direct specific actions to this obstacle.

Pro-sociality without empathy.

Empathy, the capacity to recognize and share feelings experienced by another individual, is an important trait in humans, but is not the same as pro-sociality, the tendency to behave so as to benefit another individual. Given the importance of understanding empathy's evolutionary emergence, it is unsurprising that many studies attempt to find evidence for it in other species. To address the question of what should constitute evidence for empathy, we offer a critical comparison of two recent studies of rescuing behaviour that report similar phenomena but are interpreted very differently by their authors.

Specialized learning in antlions (Neuroptera: Myrmeleontidae), pit-digging predators, shortens vulnerable larval stage.

Unique in the insect world for their extremely sedentary predatory behavior, pit-dwelling larval antlions dig pits, and then sit at the bottom and wait, sometimes for months, for prey to fall inside. This sedentary predation strategy, combined with their seemingly innate ability to detect approaching prey, make antlions unlikely candidates for learning. That is, although scientists have demonstrated that many species of insects possess the capacity to learn, each of these species, which together represent multiple families from every major insect order, utilizes this ability as a means of navigating the environment, using learned cues to guide an active search for food and hosts, or to avoid noxious events.

Rescue behavior: Distinguishing between rescue, cooperation and other forms of altruistic behavior.

Reports of rescue behavior in non-human animals are exceedingly rare, except in ants where rescue is well known, but has not been explored experimentally until recently. Although we predict that rescue behavior should be limited to circumstances in which the victim and the rescuer are highly related to one another, or in which unrelated individuals must cooperate very closely with one another, we also predict that it is likely to be far more common than the current literature would suggest. To address this oversight, we propose a rigorous definition of rescue behavior, one that helps researchers to focus on its necessary and sufficient components, at the same time that it helps to differentiate rescue behavior from cooperation and other forms of helping behavior.

Ants, Cataglyphis cursor, use precisely directed rescue behavior to free entrapped relatives.

Although helping behavior is ubiquitous throughout the animal kingdom, actual rescue activity is particularly rare. Nonetheless, here we report the first experimental evidence that ants, Cataglyphis cursor, use precisely directed rescue behavior to free entrapped victims; equally important, they carefully discriminate between individuals in distress, offering aid only to nestmates. Our experiments simulate a natural situation, which we often observed in the field when collecting Catagyphis ants, causing sand to collapse in the process.

Learning in a sedentary insect predator: antlions (Neuroptera: Myrmeleontidae) anticipate a long wait.

Pit-building antlions, the larvae of a winged adult insect, capture food by digging funnel-shaped pits in sand and then lying in wait, buried at the vertex, for prey to fall inside. The sedentary nature of this sit-and-wait predatory behaviour and, especially, antlions' innate ability to detect prey arrival, do not fit the typical profile of insects that possess learning capabilities. However, we show, for the first time, that learning can play an important role in this unique form of predation.

The bitter truth: sensitivity to saccharin's bitterness predicts overactivity in highly arousable female dieters.

Objective: The interaction between taste sensitivity and emotionality in rats provides a provocative view of hyperactivity. Rats that have been bred selectively for their reactivity to saccharin exhibit characteristic emotionality. When placed on restrictive diets, these rats exhibit excessive activity levels, relative to rats that are not sensitive to saccharin.