At the end of the 1920s, Tanganyika Territory experienced several serious rodent outbreaks that threatened cotton and other grain production. At the same time, regular reports of pneumonic and bubonic plague occurred in the northern areas of Tanganyika. These events led the British colonial administration to dispatch several studies into rodent taxonomy and ecology in 1931 to determine the causes of rodent outbreaks and plague disease, and to control future outbreaks. The application of ecological frameworks to the control of rodent (...) outbreaks and plague disease transmission in colonial Tanganyika Territory gradually moved from a view that prioritised 'ecological interrelations' among rodents, fleas and people to one where those interrelations required studies into population dynamics, endemicity and social organisation in order to mitigate pests and pestilence. This shift in Tanganyika anticipated later population ecology approaches on the African continent. Drawing on sources from the Tanzania National Archives, this article offers an important case study of the application of ecological frameworks in a colonial setting that anticipated later global scientific interest in studies of rodent populations and rodent-borne disease ecologies. (shrink)

ABSTRACT In a series of experiments at the National Institute of Mental Health, the animal ecologist John B. Calhoun offered rats everything they needed, except space. The resulting population explosion was followed by a series of “social pathologies”—violence, sexual deviance, and withdrawal. This essay examines the influence of Calhoun's experiments among psychologists and sociologists concerned with the effects of the built environment on health and behavior. Some saw evidence of the danger of the crowd in Calhoun's “rat cities” and fastened (...) on a method of analysis that could be transferred to the study of urban man. Others, however, cautioned against drawing analogies between rodents and humans. The ensuing dispute saw social scientists involved in a careful negotiation over the structure and meaning of Calhoun's experimental systems and, with it, over the significance of the crowd in the laboratory, institution, and city. (shrink)

Researchers working on rodent in maze studies claim that organisms use distal (far) and proximal (near) visual cues differently. I characterize the dominant working definitions researchers use for distal and proximal cues, where distal cues sit beyond an experimental apparatus (like a maze) and proximal cues sit within. Then, I present a problem: the relevant experimental apparatuses are confined to labs and cannot be used to study real-life navigation behaviors like long-distance migration. It follows that the working definitions do not (...) identify difference makers beyond those settings and do not allow for claims about distal and proximal cues to play explanatory or predictive roles for real-life navigation. Despite this, I argue that researchers should continue to treat these as working definitions for concepts that work more generally in natural environments. This calls for some conceptual engineering however, since the more generally useful concepts of “proximal” and “distal” are not well-defined. To remedy this, I present more general, ecologically valid definitions in terms of neural information about visual cues. (shrink)

Proposals to eradicate rodents threatening native seabird populations on islands using tools including poisons and—potentially—gene drives are becoming increasingly common. Focusing on the case of Gough Island, we analyze such proposals from two ethical perspectives—the value of the lives and welfare of individuals, and the conservation value of saving populations. We argue that from many ethical positions, and for both welfare and conservation reasons, a gene drive intervention, were one available, would be better than no intervention or the use (...) of poison. However, we also argue that the standard conservation stories given for island rodent eradications may ignore significant complexity. In the case of Gough Island, for instance, the rodents, as well as the seabirds, are significant reservoirs of biodiversity. Hence, rodent eradication can result in the loss of some conservation value. While this does not mean rodent eradications should be ruled out, recognizing they may bring conservation loss as well as welfare loss would be a first step toward more firmly grounded ethical justifications for eradication. (shrink)

In the quest to discover the neural bases of cognition, rigorous behavioral tools are equally as important as sophisticated tools for neural intervention. This paper evaluates several episodes in the development of a novel behavioral tool for rodent cognitive testing, the rodent touchscreen operant chamber. Using conceptual tools on offer in the philosophical literature on exploratory experimentation and control, I illuminate how optimization of this behavioral tool and an understanding of the causal knowledge it may be used to generate historically (...) has involved dynamic interplay between community-driven exploratory practices operating in parallel with causal hypothesis-driven research. (shrink)

This Open Access volume is the first book on home-cage monitoring (HCM), carefully prepared by an international team of experts to improve the outcome of animal behavior research. It offers essential information for anyone entering the world of continuous monitoring, addressing animal welfare and translatability in animal models. Comprehensively structured, the book guides you from user training through technologies, rodent models, study design, and commercialization to data analysis and sharing. HCM allows for uninterrupted monitoring of rodents during their active (...) phases with a minimum impact on the animals. This enables them to exhibit natural behaviors in a familiar environment. Moreover, continuous monitoring allows us to pick up animal welfare issues that otherwise might have been missed. As such, the present work is an indispensable contribution to the refinement of experimental conditions and animal wellbeing, ultimately enhancing data reproducibility and translational value. Alongside biomedical researchers, veterinarians and animal care personnel, also experts in animal behavior, laboratory animal science, and data science will recognize the value of this instructive and unique guide. (shrink)

This article postulates a method of determining the date of human settlement in the Canary Islands by establishing when species of mice, which are commensal with human beings and hence in all likelihood migrated with them, arrived in the archipelago. At the same time, the extinction of several species of endemic rodents may also correlate with such arrivals. The study establishes the outer limits for the arrival of the mouse species, between the 5th millennium BCE and the 15th century (...) CE, but, while indicative archaeological evidence indicates human settlement was established by around the middle of the 1st millennium BCE, the absence of conclusive dating of fossil mice remains leaves a definitive conclusion for the start of such settlement still open. (shrink)

There are two main approaches within classical cognitive science to explaining how humans can entertain mental states that integrate contents across domains. The language-based framework states that this ability arises from higher cognitive domain-specific systems that combine their outputs through the language faculty, whereas the language-independent framework holds that it comes from non-language-involving connections between such systems. This article turns on its head the most influential empirical argument for the language-based framework, an argument that originates from research on spatial reorientation. (...) I make the case that neuroscientific findings about spatial reorientation in rodents and humans bolster the language-independent framework instead. (shrink)

Communication is inherent to social relationships. Previous papers addressed the correlation between social and communicative complexity, and the origin of sociality in rodents. In subterranean social species, as the number of animals in the same burrow increases, so do interindividual contact rates. This is because of limitations in actually used tunnel length and diameter, leading to an increasing number of agonistic situations probably resulting in time loss, threatening, and fighting with danger of injuries. To avoid this, social species are (...) expected to have an increase in the number of particular vocalizations. Comparison of the adult vocal repertoire of 12 species through regression and phylogenetically independent contrasts suggests three main conclusions: social species increase their repertoire both in number and categories of vocal signals in relation to solitary species, although the coefficient was smaller in the PIC model; the number of agonistic vocalizations was also different between solitary and social species, with the latter displaying higher numbers of these calls; the percentage of agonistic vocalizations in relation to total repertoire was similar between social and solitary species, with no significant relationship between this parameter and the social structure. These results imply that agonistic vocalizations have also increased in number in social species, indicating the importance of these calls in the establishment of new relationships. As repertoire changes are essential to cope with new and frequent kinds of interactions sociality originates, these results suggest that at least for these organisms, communicative changes, especially at the level of agonistic signals, could be a necessary condition to fulfill in the path to the possibility of group living. (shrink)

Contrary to the outstanding simplistic view of the taste system, learning studies show a more complex picture. Behavioral data using conditioned taste preference and aversion tasks support the idea that mixtures involve complex interactions between individual taste cues. Evidence from taste conditioned blocking, taste perceptual learning, and taste learned preferences is considered to support such a view. Greater support for research in taste learning and memory is required for a complete understanding of taste recognition.

Translation failure occurs when a treatment shown to be safe and effective in one type of population does not produce the same result in another. We are currently in a crisis involving the translatability of preclinical studies to human populations. Animal trials are no better than a coin toss at predicting the safety and efficacy of drugs in human trials, and the high failure rate of drugs entering human trials suggests that most of the suffering of laboratory animals is futile, (...) creating no commensurate benefit for human patients. Here, I argue that animal ethics committees have a role to play in getting us out of this crisis. Inadequate representation is a known contributor to translation failures and is a matter of both scientific and ethical concern. Ethical review committees have the authority to address it by reprioritising the values already enshrined in their guiding principles. (shrink)

Home cage monitoring (HCM) offers a transformative approach to understanding rodent behavior and physiology in biomedical research. This chapter reviews the most commonly used mouse and rat models in HCM. Mice, particularly the C57BL/6 inbred strain, dominate the field due to their genetic homogeneity, ease of breeding, and well-characterized genome. Despite their advantages, researchers must consider strain- (and substrain-) specific traits that can be either strengths or limitations of the model (such as susceptibility to diet-induced obesity, age-related hearing loss, retinal (...) degeneration and visual impairment, and differences in locomotor and exploratory activity). HCM allows for the continuous monitoring of behaviors such as activity and feeding, providing insights into subtle phenotypes and genetic influences on behavior. Other mouse strains, including DBA/2, 129, BALB/c, and FVB/N, offer unique behavioral profiles useful for specific research applications. In rats, strains like the Long-Evans, Dark Agouti, and Spontaneously Hypertensive Rat (SHR) are highlighted for their relevance in cognitive, metabolic, and cardiovascular studies. This chapter underscores the importance of selecting appropriate strains for HCM studies, considering genetic background, behavioral traits, and experimental goals. The continuous, automated nature of HCM systems promises to advance our understanding of complex behaviors and physiological responses, paving the way for innovative approaches in biomedical research. (shrink)

Head direction (HD) cells, abundant in the rat postsubiculum and anterior thalamic nuclei, fire maximally when the rat’s head is facing a particular direction. The activity of a population of these cells forms a distributed representation of the animal’s current heading. We describe a neural network model that creates a stable, distributed representation of head direction and updates that representation in response to angular velocity information. In contrast to earlier models, our model of the head direction system accurately tracks a (...) series of actual rat head rotations, and, using biologically plausible neurons, it fits the single-cell tuning curves of real HD cells recorded from rats executing those same rotations. The model makes neurophysiological predictions that can be tested using current technologies. (shrink)

Phylogeography and zooarchaeology are largely separate disciplines, yet each interrogates relationships between humans and commensal species. Knowledge gained about human history from studies of four commensal rats (Rattus rattus, R. tanezumi, R. exulans, and R. norvegicus) is outlined, and open questions about their spread alongside humans are identified. Limitations of phylogeographic and zooarchaeological studies are highlighted, then how integration would increase understanding of species’ demographic histories and resultant inferences about human societies is discussed. How rat expansions have informed the understanding (...) of human migration, urban settlements, trade networks, and intra‐ and interspecific competition is reviewed. Since each rat species is associated with different human societies, they identify unique ecological and historical/cultural conditions that influenced their expansion. Finally, priority research areas including nuclear genome based phylogeographies are identified using archaeological evidence to understand R. norvegicus expansion across China, multi‐wave colonization of R. rattus across Europe, and competition between R. rattus and R. norvegicus. (shrink)