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Andrew N Radford - One of the best experts on this subject based on the ideXlab platform.
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strongly bonded individuals prefer to forage together in cooperatively breeding dwarf mongoose groups
Behavioral Ecology and Sociobiology, 2021Co-Authors: Julie M Kern, Andrew N RadfordAbstract:In many social species, group members form strong social bonds. Such strong bonds are well-known to generate long-term fitness benefits, but they are also expected to influence short-term behavioural decisions. Here, we use field observations and an experimental manipulation to investigate whether variation in social-bond strength (as determined from grooming interactions) influences nearest-neighbour choices while foraging in wild dwarf mongooses (Helogale parvula). Preferred grooming partnerships (PGPs), representing particularly strong bonds, were found predominately between male–female dyads but among a range of dominance-status dyads. When searching for food, dwarf mongooses with PGPs were more likely than expected by chance to forage close to a preferred grooming partner. Foraging near a strongly bonded groupmate might reduce the predation risk or increase foraging opportunities and the transfer of social information. In addition, there could be stress-reducing benefits, although our field experiment provided no evidence that nearest-neighbour preferences for strongly bonded groupmates were additionally favoured, or indeed disrupted, in the aftermath of a short-term stressful event. Investigating the potential influence of strong social bonds on short-term behavioural decisions with potential fitness consequences is important for our understanding of social interactions and cooperation. Enduring, close social bonds between individuals provide considerable long-term health and fitness benefits, but are also expected to influence short-term behavioural decisions. We investigated whether social-bond strength (as determined from grooming interactions) influenced foraging decisions in cooperatively breeding dwarf mongoose groups. We found particularly strong social bonds in the form of preferred grooming partnerships in a subset of male–female dyads. Dwarf mongoose foraging decisions were affected by the strength of their social relationships with groupmates: individuals with preferred grooming partners preferred to have these individuals as their nearest neighbours when searching for food. We used a field-based experimental manipulation to investigate whether stressful events impact nearest-neighbour choices, but found no evidence that preferences to forage near strongly bonded groupmates were disrupted or more additionally favoured in the aftermath of a stressful event. Our current work extends understanding of how social bonds can potentially influence within-group behaviour.
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wild dwarf mongooses produce general alert and predator specific alarm calls
Behavioral Ecology, 2017Co-Authors: Katie Collier, Andrew N Radford, Simon W Townsend, Marta B. ManserAbstract:Many species produce alarm calls in response to predator threats. Whilst these can be general alert calls, some are urgency-based, indicating perceived threat level, some are predator-specific, indicating the predator type present, and some encode information about both urgency level and predator type. Predator-specific calls given to a narrow range of stimuli and which elicit a specific, adaptive, response from the receiver are termed functionally referential. Differing escape strategies, habitat structural complexity and sociality may favor the evolution of functionally referential calls. A study of one captive group of dwarf 3 mongooses (Helogale parvula) suggested their alarm calls could transmit information about species, distance and elevation of predators. Using recordings of natural predator encounters, predator presentations and audio playbacks, we investigated the alarm-call system in seven wild dwarf mongoose groups. We recorded 11 different alarm-call types given to nine stimulus categories. Of the five commonly emitted alarm-call types, three appeared to be non-specific and two predator-specific, given to aerial and terrestrial predators respectively. The remaining six call types were rarely produced. Furthermore, aerial alarms were given to a narrower range of stimuli than their terrestrial alarm calls, which were given to both visible terrestrial predators and secondary cues of predators. Unlike other mongoose species, dwarf mongoose seem to use the same alarm-call type for both physically present terrestrial predators and secondary cues of their presence. We argue that detailed knowledge of species’ alarm-call systems under natural conditions can shed light on the evolutionary emergence of different types of alarm calls.
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anthropogenic noise alters dwarf mongoose responses to heterospecific alarm calls
Environmental Pollution, 2017Co-Authors: Amy Morrisdrake, Julie M Kern, Anna M Bracken, Andrew N RadfordAbstract:Anthropogenic noise is an evolutionarily novel and widespread pollutant in both terrestrial and aquatic habitats. Despite increasing evidence that the additional noise generated by human activities can affect vocal communication, the majority of research has focused on the use of conspecific acoustic information, especially sexual signals. Many animals are known to eavesdrop on the alarm calls produced by other species, enhancing their likelihood of avoiding predation, but how this use of heterospecific information is affected by anthropogenic noise has received little empirical attention. Here, we use two field-based playback experiments on a habituated wild population of dwarf mongooses (Helogale parvula) to determine how anthropogenic noise influences the response of foragers to heterospecific alarm calls. We begin by demonstrating that dwarf mongooses respond appropriately to the alarm calls of sympatric chacma baboons (Papio ursinus) and tree squirrels (Paraxerus cepapi); fleeing only to the latter. We then show that mongoose foragers are less likely to exhibit this flee response to tree squirrel alarm calls during road-noise playback compared to ambient-sound playback. One explanation for the change in response is that noise-induced distraction or stress result in maladaptive behaviour. However, further analysis revealed that road-noise playback results in increased vigilance and that mongooses showing the greatest vigilance increase are those that do not subsequently exhibit a flee response to the alarm call. These individuals may therefore be acting appropriately: if the greater gathering of personal information indicates the absence of an actual predator despite an alarm call, the need to undertake costly fleeing behaviour can be avoided. Either way, our study indicates the potential for anthropogenic noise to interfere with the use of acoustic information from other species, and suggests the importance of considering how heterospecific networks are affected by this global pollutant.
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social bond strength influences vocally mediated recruitment to mobbing
Biology Letters, 2016Co-Authors: Julie M Kern, Andrew N RadfordAbstract:Strong social bonds form between individuals in many group-living species, and these relationships can have important fitness benefits. When responding to vocalizations produced by groupmates, receivers are expected to adjust their behaviour depending on the nature of the bond they share with the signaller. Here we investigate whether the strength of the signaller–receiver social bond affects response to calls that attract others to help mob a predator. Using field-based playback experiments on a habituated population of wild dwarf mongooses ( Helogale parvula ), we first demonstrate that a particular vocalization given on detecting predatory snakes does act as a recruitment call; receivers were more likely to look, approach and engage in mobbing behaviour than in response to control close calls. We then show that individuals respond more strongly to these recruitment calls if they are from groupmates with whom they are more strongly bonded (those with whom they preferentially groom and forage). Our study, therefore, provides novel evidence about the anti-predator benefits of close bonds within social groups.
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sentinel dominance status influences forager use of social information
Behavioral Ecology, 2016Co-Authors: Julie M Kern, Seirian Sumner, Andrew N RadfordAbstract:Animals in social groups can acquire information about the need for antipredator behavior by personally sampling the environment or from information provided by others. Use of such social information is expected to be adjusted according to its reliability, but experimental tests are rare and tend to focus just on alarm calls. We use detailed behavioral observations, acoustic analyses, and playback experiments to investigate how differences in sentinel dominance status affect the behavioral decisions of foraging dwarf mongooses (Helogale parvula). Dominant individuals acted as sentinels considerably more often than subordinate group members and used higher sentinel posts for guarding, making them potentially higher-quality sentinels in terms of experience and optimal positioning for predator detection. Surveillance calls produced during sentinel bouts contained vocal information about dominance status. Playback experiments showed that foragers used surveillance calls to detect sentinel presence and identity, and adjusted their vigilance behavior accordingly. When a dominant sentinel was on duty, compared with a subordinate groupmate, foragers increased reliance on social information, gathered less information through personal vigilance, and focused more on foraging. Our study contributes novel evidence that a major benefit of individual- and class-specific vocalizations is the potential to assess differences in caller information quality.
Julie M Kern - One of the best experts on this subject based on the ideXlab platform.
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strongly bonded individuals prefer to forage together in cooperatively breeding dwarf mongoose groups
Behavioral Ecology and Sociobiology, 2021Co-Authors: Julie M Kern, Andrew N RadfordAbstract:In many social species, group members form strong social bonds. Such strong bonds are well-known to generate long-term fitness benefits, but they are also expected to influence short-term behavioural decisions. Here, we use field observations and an experimental manipulation to investigate whether variation in social-bond strength (as determined from grooming interactions) influences nearest-neighbour choices while foraging in wild dwarf mongooses (Helogale parvula). Preferred grooming partnerships (PGPs), representing particularly strong bonds, were found predominately between male–female dyads but among a range of dominance-status dyads. When searching for food, dwarf mongooses with PGPs were more likely than expected by chance to forage close to a preferred grooming partner. Foraging near a strongly bonded groupmate might reduce the predation risk or increase foraging opportunities and the transfer of social information. In addition, there could be stress-reducing benefits, although our field experiment provided no evidence that nearest-neighbour preferences for strongly bonded groupmates were additionally favoured, or indeed disrupted, in the aftermath of a short-term stressful event. Investigating the potential influence of strong social bonds on short-term behavioural decisions with potential fitness consequences is important for our understanding of social interactions and cooperation. Enduring, close social bonds between individuals provide considerable long-term health and fitness benefits, but are also expected to influence short-term behavioural decisions. We investigated whether social-bond strength (as determined from grooming interactions) influenced foraging decisions in cooperatively breeding dwarf mongoose groups. We found particularly strong social bonds in the form of preferred grooming partnerships in a subset of male–female dyads. Dwarf mongoose foraging decisions were affected by the strength of their social relationships with groupmates: individuals with preferred grooming partners preferred to have these individuals as their nearest neighbours when searching for food. We used a field-based experimental manipulation to investigate whether stressful events impact nearest-neighbour choices, but found no evidence that preferences to forage near strongly bonded groupmates were disrupted or more additionally favoured in the aftermath of a stressful event. Our current work extends understanding of how social bonds can potentially influence within-group behaviour.
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anthropogenic noise alters dwarf mongoose responses to heterospecific alarm calls
Environmental Pollution, 2017Co-Authors: Amy Morrisdrake, Julie M Kern, Anna M Bracken, Andrew N RadfordAbstract:Anthropogenic noise is an evolutionarily novel and widespread pollutant in both terrestrial and aquatic habitats. Despite increasing evidence that the additional noise generated by human activities can affect vocal communication, the majority of research has focused on the use of conspecific acoustic information, especially sexual signals. Many animals are known to eavesdrop on the alarm calls produced by other species, enhancing their likelihood of avoiding predation, but how this use of heterospecific information is affected by anthropogenic noise has received little empirical attention. Here, we use two field-based playback experiments on a habituated wild population of dwarf mongooses (Helogale parvula) to determine how anthropogenic noise influences the response of foragers to heterospecific alarm calls. We begin by demonstrating that dwarf mongooses respond appropriately to the alarm calls of sympatric chacma baboons (Papio ursinus) and tree squirrels (Paraxerus cepapi); fleeing only to the latter. We then show that mongoose foragers are less likely to exhibit this flee response to tree squirrel alarm calls during road-noise playback compared to ambient-sound playback. One explanation for the change in response is that noise-induced distraction or stress result in maladaptive behaviour. However, further analysis revealed that road-noise playback results in increased vigilance and that mongooses showing the greatest vigilance increase are those that do not subsequently exhibit a flee response to the alarm call. These individuals may therefore be acting appropriately: if the greater gathering of personal information indicates the absence of an actual predator despite an alarm call, the need to undertake costly fleeing behaviour can be avoided. Either way, our study indicates the potential for anthropogenic noise to interfere with the use of acoustic information from other species, and suggests the importance of considering how heterospecific networks are affected by this global pollutant.
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social bond strength influences vocally mediated recruitment to mobbing
Biology Letters, 2016Co-Authors: Julie M Kern, Andrew N RadfordAbstract:Strong social bonds form between individuals in many group-living species, and these relationships can have important fitness benefits. When responding to vocalizations produced by groupmates, receivers are expected to adjust their behaviour depending on the nature of the bond they share with the signaller. Here we investigate whether the strength of the signaller–receiver social bond affects response to calls that attract others to help mob a predator. Using field-based playback experiments on a habituated population of wild dwarf mongooses ( Helogale parvula ), we first demonstrate that a particular vocalization given on detecting predatory snakes does act as a recruitment call; receivers were more likely to look, approach and engage in mobbing behaviour than in response to control close calls. We then show that individuals respond more strongly to these recruitment calls if they are from groupmates with whom they are more strongly bonded (those with whom they preferentially groom and forage). Our study, therefore, provides novel evidence about the anti-predator benefits of close bonds within social groups.
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sentinel dominance status influences forager use of social information
Behavioral Ecology, 2016Co-Authors: Julie M Kern, Seirian Sumner, Andrew N RadfordAbstract:Animals in social groups can acquire information about the need for antipredator behavior by personally sampling the environment or from information provided by others. Use of such social information is expected to be adjusted according to its reliability, but experimental tests are rare and tend to focus just on alarm calls. We use detailed behavioral observations, acoustic analyses, and playback experiments to investigate how differences in sentinel dominance status affect the behavioral decisions of foraging dwarf mongooses (Helogale parvula). Dominant individuals acted as sentinels considerably more often than subordinate group members and used higher sentinel posts for guarding, making them potentially higher-quality sentinels in terms of experience and optimal positioning for predator detection. Surveillance calls produced during sentinel bouts contained vocal information about dominance status. Playback experiments showed that foragers used surveillance calls to detect sentinel presence and identity, and adjusted their vigilance behavior accordingly. When a dominant sentinel was on duty, compared with a subordinate groupmate, foragers increased reliance on social information, gathered less information through personal vigilance, and focused more on foraging. Our study contributes novel evidence that a major benefit of individual- and class-specific vocalizations is the potential to assess differences in caller information quality.
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tree climbing and denning by common dwarf mongoose Helogale parvula
2014Co-Authors: Michael R Hoffmann, R L Roberts, Julie M KernAbstract:Common Dwarf Mongoose Helogale parvula is a small, social mongoose (Herpestidae) widely distributed from the Horn of Africa to the north-eastern parts of South Africa’s KwaZulu– Natal province (Kingdon 1977, Creel 2013). Creel (2013) described it as most common in open woodlands, thickets and wooded savannas, particularly where there are termitaria, rock outcroppings or crevices, or hollow logs for use as dens. Waser et al. (1995) suggested that the most important determinant of Common Dwarf Mongoose habitat preference is the density of suitable dens, with active or quiescent termite mounds (especially those of Macrotermes) being particularly favoured. While it is often observed clambering on termitaria, rocks or logs or branches of fallen trees, it is not commonly considered a climber and tree denning is rarely recorded. Indeed, Rautenbach (1982: 140) noted that “Helogale parvula
Radford, Andrew N. - One of the best experts on this subject based on the ideXlab platform.
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Dwarf mongoose alarm calls : investigating a complex non-human animal call
The Royal Society Publishing, 2020Co-Authors: Collier Katie, Radford, Andrew N., Stoll Sabine, Watson, Stuart K., Manser, Marta B., Bickel Balthasar, Townsend, Simon W.Abstract:Communication plays a vital role in the social lives of many species and varies greatly in complexity. One possible way to increase communicative complexity is by combining signals into longer sequences, which has been proposed as a mechanism allowing species with a limited repertoire to increase their communicative output. In mammals, most studies on combinatoriality have focused on vocal communication in non-human primates. Here, we investigated a potential combination of alarm calls in the dwarf mongoose (Helogale parvula), a non-primate mammal. Acoustic analyses and playback experiments with a wild population suggest: i) that dwarf mongooses produce a complex call type (T3) which, at least at the surface level, seems to comprise units that are not functionally different to two meaningful alarm calls (aerial and terrestrial); and ii) that this T3 call functions as a general alarm, produced in response to a wide range of threats. Using a novel approach, we further explored multiple interpretations of the T3 call based on the information content of the apparent comprising calls and how they are combined. We also considered an alternative, non-combinatorial, interpretation that frames T3 as the origin, rather than the product, of the individual alarm calls. This study complements previous knowledge of vocal combinatoriality in non-primate mammals and introduces an approach that could facilitate comparisons between different animal and human communication systems
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Data from: Experimental field evidence that out-group threats influence within-group behaviour
2019Co-Authors: Morris-drake Amy, Kern, Julie M., Christensen Charlotte, Radford, Andrew N.Abstract:In social species, conspecific outsiders present various threats to groups and their members. These out-group threats are predicted to affect subsequent within-group interactions (e.g. affiliation and aggression) and individual behaviour (e.g. foraging and vigilance decisions). However, experimental investigations of such consequences are rare, especially in natural conditions. We used field-based call playbacks and faecal presentations on habituated wild dwarf mongooses (Helogale parvula)—a cooperatively breeding, territorial species—to examine post-interaction responses to the simulated threat of a rival group. Dwarf mongooses invested more in grooming of groupmates, foraged closer together and more regularly acted as sentinels (a raised guard) after encountering indicators of rival-group presence compared to control conditions. These behavioural changes likely arise from greater anxiety and, in the case of increased vigilance, the need to seek additional information about the threat. The influence of an out-group threat lasted at least 1 h but individuals of different dominance status and sex responded similarly, potentially because all group members suffer costs if a contest with rivals is lost. Our results provide field-based experimental evidence from wild animals that out-group threats can influence within-group behaviour and decision-making, and suggest the need for greater consideration of the lasting impacts of social conflict
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Wild dwarf mongooses produce general alert and predator-specific alarm calls
'Oxford University Press (OUP)', 2017Co-Authors: Collier Katie, Radford, Andrew N., Townsend, Simon W., Manser, Marta B.Abstract:Many species produce alarm calls in response to predator threats. Whilst these can be general alert calls, some are urgency-based, indicating perceived threat level, some are predator-specific, indicating the predator type present, and some encode information about both urgency level and predator type. Predator-specific calls given to a narrow range of stimuli and which elicit a specific, adaptive, response from the receiver are termed functionally referential. Differing escape strategies, habitat structural complexity and sociality may favor the evolution of functionally referential calls. A study of one captive group of dwarf mongooses (Helogale parvula) suggested their alarm calls could transmit information about species, distance, and elevation of predators. Using recordings of natural predator encounters, predator presentations and audio playbacks, we investigated the alarm-call system in 7 wild dwarf mongoose groups. We recorded 11 different alarm-call types given to 9 stimulus categories. Of the 5 commonly emitted alarm-call types, 3 appeared to be non-specific and 2 predator-specific, given to aerial and terrestrial predators respectively. The remaining 6 call types were rarely produced. Furthermore, aerial alarms were given to a narrower range of stimuli than their terrestrial alarm calls, which were given to both visible terrestrial predators and secondary cues of predators. Unlike other mongoose species, dwarf mongoose seem to use the same alarm-call type for both physically present terrestrial predators and secondary cues of their presence. We argue that detailed knowledge of species’ alarm-call systems under natural conditions can shed light on the evolutionary emergence of different types of alarm calls
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Data from: Rival group scent induces changes in dwarf mongoose immediate behaviour and subsequent movement
2016Co-Authors: Christensen Charlotte, Kern, Julie M., Bennitt Emily, Radford, Andrew N.Abstract:In many social species, groups of animals defend a shared territory against rival conspecifics. Intruders can be detected from a variety of cues, including fecal deposits, and the strength of response is expected to vary depending on the identity of the rival group. Previous studies examining differences in response to neighbor and stranger groups have focused on the immediate response to the relevant cues. Here, we investigated how simulated intrusions of rival groups affect both immediate responses and postinspection movement patterns. To do so, we used a fecal translocation experiment at latrine sites within the territories of dwarf mongoose Helogale parvula groups. Immediate responses were adjusted to the level of threat, with greater scent-marking behavior, time spent at the latrine, and group-member participation when groups were presented with fecal matter from out-group rivals relative to control (own group and herbivore) feces. Subsequent movement of the group was also affected by threat level, with a decrease in speed and distance covered following simulated intrusions by out-group rivals compared with control conditions. However, there were no significant differences in immediate responses or post-latrine movement patterns when comparing simulated neighbor and stranger intrusions. These results indicate that territorial intrusions can elicit not just an immediate change in behavior but more far-reaching consequences in terms of movement dynamics. They also raise the possibility that neighbor–stranger discrimination predictions are not necessarily as clear-cut as previously described
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Data from: Social-bond strength influences vocally-mediated recruitment to mobbing
2016Co-Authors: Kern, Julie M., Radford, Andrew N.Abstract:Strong social bonds form between individuals in many group-living species, and these relationships can have important fitness benefits. When responding to vocalizations produced by groupmates, receivers are expected to adjust their behaviour depending on the nature of the bond they share with the signaller. Here we investigate whether the strength of the signaller–receiver social bond affects response to calls that attract others to help mob a predator. Using field-based playback experiments on a habituated population of wild dwarf mongooses (Helogale parvula), we first demonstrate that a particular vocalization given on detecting predatory snakes does act as a recruitment call; receivers were more likely to look, approach and engage in mobbing behaviour than in response to control close calls. We then show that individuals respond more strongly to these recruitment calls if they are from groupmates with whom they are more strongly bonded (those with whom they preferentially groom and forage). Our study, therefore, provides novel evidence about the anti-predator benefits of close bonds within social groups
Stephen J. O'brien - One of the best experts on this subject based on the ideXlab platform.
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The Ancestral Carnivore Karyotype (2n = 38) Lives Today in Ringtails
The Journal of heredity, 2008Co-Authors: William G. Nash, Polina L Perelman, Joan C. Menninger, Hesed Padilla-nash, Gary Stone, Stephen J. O'brienAbstract:Chromosome painting was used to investigate the conservation of high-resolution longitudinal 4',6-diamidino-2-phenylindole (DAPI)/G bands in Carnivore chromosomes. Cat (Felis catus) and raccoon dog (Nyctereutes procyonoides) painting probes were hybridized to the ringtail (Bassaricus astutus), dwarf mongoose (Helogale parvula) , and Malagasy civet (Fossa fossa) to identify homologous chromosome elements. The patterns of chromosome segment homology among Carnivore species allowed us to reconstruct and propose the disposition of a high-resolution banded ancestral carnivore karyotype (ACK). Three bi-armed chromosomes consistently found among Caniformia species are represented as 6 homologous acrocentric chromosomes among Feliformia species of Carnivora. However, reexamination of the most basal of Feliformia species, the African palm civet Nandinia, revealed the presence of the 3 heretofore Caniformia bi-armed chromosomes. Because these 3 bi-armed chromosomes are found in both Caniformia and Feliformia lineages, they are presumed ancestral for all Carnivora, suggesting that the ACK chromosome number would be 38, rather than the previously supposed 42. Banded chromosomes of the ACK are used to evaluate the consistency between recently determined molecular phylogenetic relationships and postulated cytogenetic dynamics in the same Carnivore species.
Marta B. Manser - One of the best experts on this subject based on the ideXlab platform.
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wild dwarf mongooses produce general alert and predator specific alarm calls
Behavioral Ecology, 2017Co-Authors: Katie Collier, Andrew N Radford, Simon W Townsend, Marta B. ManserAbstract:Many species produce alarm calls in response to predator threats. Whilst these can be general alert calls, some are urgency-based, indicating perceived threat level, some are predator-specific, indicating the predator type present, and some encode information about both urgency level and predator type. Predator-specific calls given to a narrow range of stimuli and which elicit a specific, adaptive, response from the receiver are termed functionally referential. Differing escape strategies, habitat structural complexity and sociality may favor the evolution of functionally referential calls. A study of one captive group of dwarf 3 mongooses (Helogale parvula) suggested their alarm calls could transmit information about species, distance and elevation of predators. Using recordings of natural predator encounters, predator presentations and audio playbacks, we investigated the alarm-call system in seven wild dwarf mongoose groups. We recorded 11 different alarm-call types given to nine stimulus categories. Of the five commonly emitted alarm-call types, three appeared to be non-specific and two predator-specific, given to aerial and terrestrial predators respectively. The remaining six call types were rarely produced. Furthermore, aerial alarms were given to a narrower range of stimuli than their terrestrial alarm calls, which were given to both visible terrestrial predators and secondary cues of predators. Unlike other mongoose species, dwarf mongoose seem to use the same alarm-call type for both physically present terrestrial predators and secondary cues of their presence. We argue that detailed knowledge of species’ alarm-call systems under natural conditions can shed light on the evolutionary emergence of different types of alarm calls.