Biology subjects

Manser, M.

Publications and source records attributed to Manser, M..

6 recordsLinked to original sources

bioRxiv2025

The bind of the burrow: space use is dominated by selection for burrow habitat over foraging habitat in an arid-adapted carnivore

Our understanding of habitat selection in wild vertebrates has been heavily influenced by observations of preferred foraging areas. However, foraging is only one of many ways animals interact with their environment, and preferences for habitat features that support resting, breeding, and safety, along with trade-offs between these needs, remain underexplored. These trade-offs are likely to be particularly acute in complex environments where these needs are met in different locations. Using a long-term dataset of movements and life history, we examine how preferences for foraging areas and burrow sites shape space use in Kalahari meerkats (Suricata suricatta). Meerkats cannot dig new sleeping and breeding burrows and must use those abandoned by other species, potentially generating trade-offs in daily space use if overnight refuges are far from optimal foraging areas. We find that space use is strongly anchored by burrow location, with burrows in calcareous pans and dry riverbed ("white sand") habitat being preferred year-round and showing lower burrow switching rates. However, white sand areas were not preferred for foraging, and yielded lower weight gains, particularly during the dry season. As a result, meerkats faced a trade-off between optimal burrow locations and productive foraging grounds, as indicated by faster, longer, and more energetically costly travel when moving through or waking up in white sands. Our results suggest that changes in the distribution or abundance of key burrow-constructing species in desert environments may have cascading effects on the many secondary burrow-using species that depend on them for survival and reproduction. More broadly, our results highlight that limited refuge availability across the landscape can impose strong ecological constraints on animals and may restrict behavioural plasticity under environmental change, particularly if productive foraging areas shift.

ecology↗

bioRxiv2025

IFNAR1. Neutrophils Orchestrate Chronic Inflammatory Damage Through Mitochondrial Remodeling

Neutrophils are abundant innate effector cells that drive mucosal inflammation, yet the mechanisms by which they contribute to chronic inflammatory diseases across distinct tissues remain incompletely understood. Here, by reanalyzing single-cell RNA-seq datasets from patients with inflammatory bowel disease (IBD) and chronic obstructive pulmonary disease (COPD), we identify a shared neutrophil activation program enriched for type I interferon (IFN) signaling, nuclear factor-{kappa}B (NF-{kappa}B) and AP-1 transcriptional regulators, and effector pathways including NETosis, degranulation, and leukocyte trafficking. To interrogate these signatures, we established a CRISPR-compatible neutrophil differentiation platform from adult CD34 progenitors, which yielded cells closely resembling primary neutrophils at transcriptomic, proteomic, and functional levels. A targeted CRISPR-Cas9 screen revealed a central role for the mitochondrial iron transporter mitoferrin-1 (SLC25A37) in coordinating neutrophil oxidative phosphorylation, NET formation, and type I IFN production downstream of TLR9. Mechanistically, we show that NET-derived citrullinated histones activate an autocrine IFN-IFNAR1 loop, amplifying neutrophil inflammatory functions without impairing phagocytosis. Disruption of this loop, through IFNAR1 depletion or blockade, dampened neutrophil-driven tissue damage in human intestinal and alveolar organoid co-cultures as well as in murine models of colitis and cigarette smoke-induced lung inflammation. These findings uncover a conserved IFN-driven metabolic circuit in neutrophils that underpins pathology across chronic mucosal diseases and identify IFNAR1 as a therapeutic node to selectively disarm neutrophil-mediated tissue injury.

immunology↗

bioRxiv2024

Vocal grooming in meerkats: weakly bonded subordinatescall more in response to dominants

Physical grooming is often used to maintain social bonds in animal groups, but opportunities for grooming each group member may be limited. Vocal exchanges have been proposed as an alternative way to sustain social ties without requiring physical proximity. To explore the link between vocal exchanges and social relationships, we examined the effect of dominance and dyadic bond strength of the interacting partners on the intensity of vocal interaction in meerkats (Suricata suricatta). Focusing on sunning calls, socially facilitated vocalisations produced when meerkats warm themselves in the sun, we conducted experiments where we played sunning calls to individuals and recorded their responses. Overall, subordinate individuals showed an increased call rate when responding to calls from dominants. Tie strength showed a weak trend that differed across dyad types. These results support the notion of meerkat sunning calls having a social regulatory function, possibly as a bonding or appeasing signal, mainly directed to dominant individuals. Our results reflect the dichotomy between the subordinate and dominant individuals and underscore the strategic nature of social relationships within a despotic society. Engaging in continuous reciprocal interactions can signify commitment, promoting tolerance and cooperation. Investing in such interaction with influential dominants could lower the chances of aggression and would fit the vocal grooming functionality of such call exchanges. Further work establishing causal links between vocal interaction patterns and long-term relationship outcomes will be crucial for understanding the scope of vocal grooming as a complement or alternative to physical affiliation across species. LAY SUMMARYMeerkats use more than grooming to manage their social relationships--they also exchange short calls while warming in the sun. Playback of these "sunning calls" to wild meerkats led to increased calling by listeners, particularly when subordinates heard dominants. Females responded somewhat more than males, and social bond strength had a modest influence on calling patterns. Such vocal exchanges may function as "vocal grooming," helping maintain relationships at a distance.

animal behavior and cognition↗

bioRxiv2023

A female-biased gene expression signature of dominance in cooperatively breeding meerkats

Dominance is a primary determinant of social dynamics and resource access in social animals. Recent studies show that dominance is also reflected in the gene regulatory profiles of peripheral immune cells. However, the strength and direction of this relationship differs across the species and sex combinations investigated, potentially due to variation in the predictors and energetic consequences of dominant status. To test this possibility, we investigated the association between social status and gene expression in the blood of wild meerkats (Suricata suricatta; n=113 unique individuals), including in response to lipopolysaccharide, Gardiquimod, and glucocorticoid stimulation. Meerkats are cooperatively breeding social carnivores in which breeding females physically outcompete other females to suppress reproduction, resulting in high reproductive skew. They therefore present an opportunity to disentangle the effects of social dominance from those of sex per se. We identify a sex-specific signature of dominance, including 1,045 differentially expressed genes in females but none in males. Dominant females exhibit elevated activity in innate immune pathways and an exacerbated response to LPS challenge. In this respect, female meerkats resemble wild male baboons (for which similar data are available), where physical competition is also central to determining rank hierarchies and mating effort is high. However, they differ from female primates in which social status is nepotistically determined. Our results support the hypothesis that the gene regulatory signature of social status depends on the determinants and energetic costs of social dominance. They also support potential life history trade-offs between investment in reproduction versus somatic maintenance.

animal behavior and cognition↗

bioRxiv2020

Mobbing-like response to secondary predator cues is not a form of teaching in meerkats

Across many taxa, individuals learn how to detect, recognise and respond to predators via social learning. Learning to recognise and interpret predator cues is essential in the accurate assessment of risk. Cues can come directly from a predators presence (visual, acoustic) or from secondary predator cues (SPCs, such as hair/feathers, urine or faeces) left in the environment. Animals show various responses to encountering SPCs, which are thought to act in reducing risk to the individual. Meerkats, Suricata suricatta, show a response to SPCs not described in any other species: they display a mobbing-like behaviour. The function of this behaviour is unclear as unlike mobbing, the response it so closely resembles, it cannot serve to drive predators away. We used experiments to investigate whether adults may use this mobbing-like response to teach naive young how to recognise and respond to predators. Meerkats are known to teach pups hunting skills, but there is as yet no evidence that any species other than humans teaches across multiple contexts. We used experimental presentations of SPCs to test whether wild adult meerkats respond more intensely to SPCs in the presence of naive pups, as would be expected if the behaviour serves to promote learning. Contrary to this prediction, response intensity was lower when pups were present than when they were absent, and declined as the number of pups in the group increased, possibly due to costs associated with foraging with dependent young. Response intensity instead increased with increasing group size, number of group members interacting with the cue, and varied with predator cue type. These results suggest that the mobbing-like response to SPCs is not a form of teaching in meerkats. Instead, this behaviour may function to increase the recruitment of others to investigate the SPC. Exposing group members to SPCs may better inform them of the nature of the threat, facilitating more effective defensive group responses.

animal behavior and cognition↗

bioRxiv2020

Mobbing-like response to secondary predator cues informs group behaviour in wild meerkats

The assessment of current risk is essential in informing defensive behaviours. Many animals use cues left behind by predators, known as secondary predator cues (SPCs), to assess risk and respond appropriately. However, meerkats, Suricata suricatta, exhibit seemingly unique mobbing-like responses to these cues. The benefit of this high-intensity recruitment response is unclear, as unlike genuine mobbing, it cannot help to drive the predator away. One potential explanation is that mobbing-like responses promote information gathering and collective decision-making by the whole group. To examine this, we investigated (i) how meerkats responses to SPCs differ from mobbing live animals and (ii) the subsequent behavioural changes following a SPC encounter. Using a dataset gathered over a 20-year period, we first compared the rate of SPC recruitment versus the rate of animal mobbing. We then investigated changes in behaviour (alarm calling, sentinel bouts, distance travelled and pup provisioning) in the hour before and after a SPC encounter. Abiotic factors did not affect recruitment rate to SPCs or live animals, or influence the change in behavioural responses following a SPC encounter. The presence of pups reduced response rate to SPCs, but had no effect on animal mobbing rate, supporting experimental findings that responses towards SPCs are unlikely to function as a form of teaching. Alarm calling rate increased and the distance travelled by the group decreased following a SPC encounter, and were unaffected by the presence of pups or abiotic conditions. The results indicate group-level behavioural changes following a SPC encounter, and a greater degree of plasticity in recruitment to SPCs than to live animals. This response plasticity may reflect a context-dependent need to gather information to make collective decisions for defensive behaviour according to the level of threat perceived.

animal behavior and cognition↗