Karen L. Hollis's research while affiliated with Mount Holyoke College and other places

... This is a well-known non-invasive method for marking individuals and has been used without problem in A. carolinensis and other lizard species (e.g. Rodda et al., 1988;Robson and Miles, 2000;Lopez and Martin, 2001;Hollis et al., 2004;Henningsen and Irschick, 2012). When individuals lost their colour markings (for example by moulting) they were caught and the markings were reapplied. ...

... Thus, in reality, the present state of each rescuer influences, and is influenced by, a complex, truly dynamically unfolding operation in which the actions of all rescuers contribute. In short, rescue in ants exhibits, yet again, that ants are not hardwired reflex automatons; instead, their execution of highly organized and precisely directed rescue behavior is one more example of their especially high cognitive capacities in general (Cheng, 2010;Kriete & Hollis, 2022;Perry et al., 2013). ...

... The pond snail Lymnaea stagnalis is an important model system for studying the causal neuronal mechanisms of associative learning and the subsequent formation of long-term memory. Lymnaea can be both classically and operantly conditioned for a number of different behaviors, and researchers have primarily focused on feeding, withdrawal, and aerial respiratory behaviors [1][2][3][4][5]. Lymnaea possesses relatively simple nervous systems, and the neuronal circuits mediating many of the behaviors that exhibit learning and memory have been well elucidated. ...

... The capture of an ant worker falling into such pits is not certain and it depends on several factors, such as the soil type and humidity level, pit size and shape, the predator actions, and the ant worker size [27][28][29][30]. The capture likelihood of some ant species is further reduced owing to rescuing behavior by their nestmates, probably attracted to a volatile pheromone emitted by the trapped worker [31,32]. When ant workers are recruited, the predator might find itself becoming the prey [33]. ...

... Many such species occur in sandy habitats, in which pits dug by pit-building predators as well as other opportunities to get trapped exist [42][43][44]. The congeneric species Cataglyphis cursor or C. piliscapa rescue workers when trapped [42,45]. ...

... An intriguing perspective of our findings is why stable individual differences in learning proficiency would be maintained within colonies. One potential explanation relies on the potential costs of cognitive functions (Mery andKawecki 2003, 2004;Mery 2005): One could hypothesize that increased ability for a cognitive trait might trade-off against the ability for another trait (Chittka et al. 2003;Hollis and Guillette 2015;Tait et al. 2019;Junca et al. 2019). Consequently, different cognitive abilities in different individuals could lead to task specialization or specific adaptation to given environmental conditions. ...

... The association of behavioural task with genetic lineage in social insects has a long history, beginning with pioneering work on the response to disease in honeybees [69][70][71]. These early results have been extended to additional tasks in honeybees such as guarding behaviour [70], and pollen and nectar foraging [19] and in ants to specialization on foraging versus waste management [72,73], rescue behaviour [74], resistance to fungal diseases [75,76] and foraging [16]. Although division of labour can occur at the very beginning of colony life [77], as specialization becomes more extensive in larger colonies, there is a greater association of specific patrilines with particular tasks which in turn leads to greater performance by colonies with higher genetic diversity [16,33,36,38,78,79]. ...

... Studies addressing the role of social structure in nervous system trait evolution often propose that social complexity, generally measured by colony size, will be negatively correlated with individual worker behavioral complexity (Anderson and McShea, 2001;Gronenberg and Riveros, 2009;O'Donnell et al., 2015) and hypothesize that relative brain investment, particularly in brain regions associated with more complex behaviors such as multi-modal learning and memory, will decrease with increasing colony size (Riveros et al., 2012;O'Donnell et al., 2015;Kamhi et al., 2016). However, individual workers of social species often show behavioral and cognitive skills comparable to solitary relatives (Gruter et al., 2011;Pasquier and Grüter, 2016;Hollis et al., 2017;Yilmaz et al., 2017), and comparisons seeking to link colony size with changes in brain structure may be complicated by confounding variables such as habitat differences or phylogenetic distance (Kamhi et al., 2016;Godfrey and Gronenberg, 2019b). Furthermore, complex collective behaviors may emerge from expanded communication systems or require relatively small changes in neural circuitry (Lihoreau et al., 2012;Bouchebti and Arganda, 2020) without changes to individual behavioral complexity (Jeanson et al., 2012;Feinerman and Korman, 2017). ...

... Although rescue behavior in C. piliscapa might at first look like a frantic scramble in aid of an entrapped nestmate, each rescue operation is in fact carefully orchestrated. Indeed, an analysis of the probabilities of transitions from one behavioral component of rescue behavior to another reveals that rescue is neither a series of random acts-the frantic scramble that it appears to be-nor a fixed pattern of behavior in which ants perform specific acts in the same robotic order (Duhoo et al., 2017). Rather, rescue behavior reflects goaldirectedness, plasticity, and memory. ...

... To some "constraints" researchers, they were studying what they found to be "the meaty part of behavior" (Garcia et al., 1972). It warrants stressing that the critique was never directed at the study of these meaty bits, which are also in focus in other sciences, such as the vibrant field of behavioural ecology (e.g., Hollis, 2017). Behavioural ecology is not atheoretical, and it connects intimately with both of the positive solutions offered below. ...