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1.
Nat Commun ; 12(1): 3717, 2021 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-34162841

RESUMO

Rawls argued that fairness in human societies can be achieved if decisions about the distribution of societal rewards are made from behind a veil of ignorance, which obscures the personal gains that result. Whether ignorance promotes fairness in animal societies, that is, the distribution of resources to reduce inequality, is unknown. Here we show experimentally that cooperatively breeding banded mongooses, acting from behind a veil of ignorance over kinship, allocate postnatal care in a way that reduces inequality among offspring, in the manner predicted by a Rawlsian model of cooperation. In this society synchronized reproduction leaves adults in a group ignorant of the individual parentage of their communal young. We provisioned half of the mothers in each mongoose group during pregnancy, leaving the other half as matched controls, thus increasing inequality among mothers and increasing the amount of variation in offspring birth weight in communal litters. After birth, fed mothers provided extra care to the offspring of unfed mothers, not their own young, which levelled up initial size inequalities among the offspring and equalized their survival to adulthood. Our findings suggest that a classic idea of moral philosophy also applies to the evolution of cooperation in biological systems.


Assuntos
Comportamento Animal/fisiologia , Herpestidae/fisiologia , Reprodução/fisiologia , Comportamento Social , Animais , Animais Recém-Nascidos , Peso Corporal/fisiologia , Cruzamento , Feminino , Masculino , Modelos Teóricos , Gravidez , Predomínio Social
2.
Viruses ; 13(2)2021 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-33672496

RESUMO

We applied the model-guided fieldwork framework to the Caribbean mongoose rabies system by parametrizing a spatially-explicit, individual-based model, and by performing an uncertainty analysis designed to identify parameters for which additional empirical data are most needed. Our analysis revealed important variation in output variables characterizing rabies dynamics, namely rabies persistence, exposure level, spatiotemporal distribution, and prevalence. Among epidemiological parameters, rabies transmission rate was the most influential, followed by rabies mortality and location, and size of the initial infection. The most influential landscape parameters included habitat-specific carrying capacities, landscape heterogeneity, and the level of resistance to dispersal associated with topography. Movement variables, including juvenile dispersal, adult fine-scale movement distances, and home range size, as well as life history traits such as age of independence, birth seasonality, and age- and sex-specific mortality were other important drivers of rabies dynamics. We discuss results in the context of mongoose ecology and its influence on disease transmission dynamics. Finally, we suggest empirical approaches and study design specificities that would provide optimal contributing data addressing the knowledge gaps identified by our approach, and would increase our potential to use epidemiological models to guide mongoose rabies control and management in the Caribbean.


Assuntos
Herpestidae/virologia , Raiva/veterinária , Distribuição Animal , Animais , Região do Caribe/epidemiologia , Feminino , Herpestidae/fisiologia , Masculino , Modelos Biológicos , Raiva/epidemiologia , Raiva/transmissão , Raiva/virologia , Vírus da Raiva/classificação , Vírus da Raiva/genética , Vírus da Raiva/isolamento & purificação , Vírus da Raiva/fisiologia
3.
BMC Biol ; 18(1): 119, 2020 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-32907574

RESUMO

BACKGROUND: The ability to recombine smaller units to produce infinite structures of higher-order phrases is unique to human language, yet evidence of animals to combine multiple acoustic units into meaningful combinations increases constantly. Despite increasing evidence for meaningful call combinations across contexts, little attention has been paid to the potential role of temporal variation of call type composition in longer vocal sequences in conveying information about subtle changes in the environment or individual differences. Here, we investigated the composition and information content of sentinel call sequences in meerkats (Suricata suricatta). While being on sentinel guard, a coordinated vigilance behaviour, meerkats produce long sequences composed of six distinct sentinel call types and alarm calls. We analysed recordings of sentinels to test if the order of the call types is graded and whether they contain additional group-, individual-, age- or sex-specific vocal signatures. RESULTS: Our results confirmed that the six distinct types of sentinel calls in addition to alarm calls were produced in a highly graded way, likely referring to changes in the perceived predation risk. Transitions between call types one step up or down the a priory assumed gradation were over-represented, while transitions over two or three steps were significantly under-represented. Analysing sequence similarity within and between groups and individuals demonstrated that sequences composed of the most commonly emitted sentinel call types showed high within-individual consistency whereby adults and females had higher consistency scores than subadults and males respectively. CONCLUSIONS: We present a novel type of combinatoriality where the order of the call types contains temporary contextual information, and also relates to the identity of the caller. By combining different call types in a graded way over long periods, meerkats constantly convey meaningful information about subtle changes in the external environment, while at the same time the temporal pattern of the distinct call types contains stable information about caller identity. Our study demonstrates how complex animal call sequences can be described by simple rules, in this case gradation across acoustically distinct, but functionally related call types, combined with individual-specific call patterns.


Assuntos
Herpestidae/fisiologia , Comportamento Social , Vocalização Animal , Acústica , Animais , Feminino , Herpestidae/psicologia , Masculino
4.
PLoS Biol ; 18(8): e3000764, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32780733

RESUMO

Tissue vibrations in the larynx produce most sounds that comprise vocal communication in mammals. Larynx morphology is thus predicted to be a key target for selection, particularly in species with highly developed vocal communication systems. Here, we present a novel database of digitally modeled scanned larynges from 55 different mammalian species, representing a wide range of body sizes in the primate and carnivoran orders. Using phylogenetic comparative methods, we demonstrate that the primate larynx has evolved more rapidly than the carnivoran larynx, resulting in a pattern of larger size and increased deviation from expected allometry with body size. These results imply fundamental differences between primates and carnivorans in the balance of selective forces that constrain larynx size and highlight an evolutionary flexibility in primates that may help explain why we have developed complex and diverse uses of the vocal organ for communication.


Assuntos
Canidae/fisiologia , Felidae/fisiologia , Herpestidae/fisiologia , Laringe/fisiologia , Primatas/fisiologia , Vocalização Animal/fisiologia , Animais , Evolução Biológica , Tamanho Corporal , Canidae/anatomia & histologia , Canidae/classificação , Felidae/anatomia & histologia , Felidae/classificação , Feminino , Herpestidae/anatomia & histologia , Herpestidae/classificação , Laringe/anatomia & histologia , Masculino , Mamíferos , Tamanho do Órgão , Filogenia , Primatas/anatomia & histologia , Primatas/classificação , Caracteres Sexuais , Fatores Sexuais , Som
5.
PLoS One ; 15(8): e0238313, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32853231

RESUMO

The efficiency of communication between animals is determined by the perception range of signals. With changes in the environment, signal transmission between a sender and a receiver can be influenced both directly, where the signal's propagation quality itself is affected, and indirectly where the senders or receivers' behaviour is impaired, impacting for example the distance between them. Here we investigated how meerkats (Suricata suricatta) in the Kalahari Desert adjust to these challenges in the context of maintaining group cohesion through contact calls. We found that meerkats changed their calling rate when signal transmission was affected indirectly due to increased dispersion of group members as during a drought, but not under typical wet conditions, when signal transmission was directly affected due to higher vegetation density. Instead under these wetter conditions, meerkats remained within proximity to each other. Overall, both direct and indirect environmental effects on signal perception resulted in an increased probability of groups splitting. In conclusion, we provide evidence that social animals can flexibly adjust their vocal coordination behaviour to cope with direct and indirect effects of the environment on signal perception, but these adjustments have limitations.


Assuntos
Comportamento Animal/fisiologia , Herpestidae/fisiologia , Vocalização Animal/fisiologia , Animais , Botsuana , Clima , Meio Ambiente , Comportamento Social
6.
Chemosphere ; 259: 127485, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32650164

RESUMO

Sub-lethal toxic impacts of chromium on hematological, biochemical and histological parameters were analyzed in the female small Indian mongoose (Urva auropuctatus) residing contaminated environment of tannery industry. Chromium bioaccumulation in the blood, liver and kidney tissue of the exposed mongooses was found elevated compared to the control mongooses' tissues. Total body weight (75.7%), liver weight (83.6%) as well as HSI (68.1%), RSI (86.2%) and the platelets counts (59.7%) were found significantly elevated, with significantly reduced RBCs (59.6%), and WBCs (64%). LFT and RFT were also found abnormal, moreover, the histopathological injuries had been distinct inside the kidney (>75%) and hepatic (>75%) tissues of exposed animals. Shrinkage and vacuolization (>75%) inside the hepatocyte expanded sinusoidal spaces and nuclear pyknosis (>75%) was evident within the hepatic tissue. Hypertrophy of epithelial cells of renal tubules and inter-renal cells of the head kidney with a reduction in tubular lumens (>75%) and vacuolization of tubules were witnessed within the kidney section. Atrophy inside the kidney inter-renal cells, glomeruli compression within the Bowman's capsules (>75%) following the necrosis in hematopoietic tissues were found in exposed animals. The present findings indicate that chronic exposure to chromium induces severe anemia, decreased serum protein concentration, hepatic and renal tissue histopathology, impairing the vital capabilities of liver, metabolic regulation, excretion, and stress homeostasis maintenance of which within the long-run may posture a severe risk to animal well-being then distress their inhabitants.


Assuntos
Cromo/toxicidade , Poluentes Ambientais/toxicidade , Herpestidae/fisiologia , Animais , Cromo/metabolismo , Poluentes Ambientais/metabolismo , Poluição Ambiental , Feminino , Herpestidae/metabolismo , Rim/metabolismo , Fígado/metabolismo , Masculino
7.
Sci Rep ; 10(1): 7461, 2020 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-32366920

RESUMO

Invasive alien species represent one of the major factors of global loss of biodiversity and disruption of natural ecosystems. The small Indian mongoose, Urva auropunctata, is considered one of the wild carnivore species with the greatest negative impact on global biodiversity. Understanding of the factors underpinning the species' distribution and potential dispersion in a context of climate change thus appears crucial in the conservation of native ecosystems. Here we modelled the current and future climatically favourable areas for the small Indian mongoose using Ecological Niche Modelling based on data sets filtrated in environmental spaces. Projections from these models show extensive current favourable geographical areas, covering continental and insular regions within tropical and sub-tropical latitudes. Moreover, predictions for 2050 reveal that climate change is likely to expand current favourable areas north of the current favourable spaces, particularly in Eastern Europe. This climate-induced expansion is particularly worrisome given that the species is already spreading in the Balkan region. Our projections suggest that it is very likely that the small Indian mongoose will have an increasing influence on ecosystems and biodiversity in Europe by 2050.


Assuntos
Biodiversidade , Mudança Climática , Herpestidae/fisiologia , Modelos Biológicos , Animais , Europa Oriental , Espécies Introduzidas
8.
Evolution ; 74(4): 740-748, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31989582

RESUMO

Sexual selection theory provides a framework for investigating the evolution of traits involved in attracting and competing for mates. Given the sexual function of such traits, studies generally focus on individual interactions (i.e., displays and contests) in explaining trait origin and persistence. We show that ecological factors can strongly influence the adaptive value of these traits, and changes to these factors can lead to rapid evolutionary change. We compared sexually selected traits in the small Indian mongoose (Urva auropunctata) between their sparsely populated native range and four tropical islands to which they were introduced within the last 150 years and where, due to a lack of interspecific competition and predation, they have become invasive and densely populated. Because of a likely increase in encounter rate, we predicted that selection on long-distance chemical advertisement by males would relax in the introduced range. Accordingly, male, but not female, anal pads (used in scent marking) decreased in size in relation to both time since introduction and population density, and their relationship to body size and condition weakened. Concurrently, as predicted by intensified sperm competition, testis size increased following introduction. The small Indian mongoose thus experienced an inversion in the relative contributions to fitness of two sexual traits, followed by their rapid evolution in line with ecological changes.


Assuntos
Comunicação Animal , Evolução Biológica , Herpestidae/fisiologia , Seleção Sexual , Animais , Hawaii , Herpestidae/anatomia & histologia , Herpestidae/genética , Índia , Espécies Introduzidas , Jamaica , Maurício , Ilhas Virgens Americanas
9.
Philos Trans R Soc Lond B Biol Sci ; 374(1770): 20180117, 2019 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-30966876

RESUMO

The phenotype of parents can have long-lasting effects on the development of offspring as well as on their behaviour, physiology and morphology as adults. In some cases, these changes may increase offspring fitness but, in others, they can elevate parental fitness at a cost to the fitness of their offspring. We show that in Kalahari meerkats ( Suricata suricatta), the circulating glucocorticoid (GC) hormones of pregnant females affect the growth and cooperative behaviour of their offspring. We performed a 3-year experiment in wild meerkats to test the hypothesis that GC-mediated maternal effects reduce the potential for offspring to reproduce directly and therefore cause them to exhibit more cooperative behaviour. Daughters (but not sons) born to mothers treated with cortisol during pregnancy grew more slowly early in life and exhibited significantly more of two types of cooperative behaviour (pup rearing and feeding) once they were adults compared to offspring from control mothers. They also had lower measures of GCs as they aged, which could explain the observed increases in cooperative behaviour. Because early life growth is a crucial determinant of fitness in female meerkats, our results indicate that GC-mediated maternal effects may reduce the fitness of offspring, but may elevate parental fitness as a consequence of increasing the cooperative behaviour of their daughters. This article is part of the theme issue 'Developing differences: early-life effects and evolutionary medicine'.


Assuntos
Comportamento Cooperativo , Glucocorticoides/metabolismo , Comportamento de Ajuda , Herpestidae/fisiologia , Animais , Variação Biológica Individual , Herpestidae/genética , Herança Materna , África do Sul
10.
Philos Trans R Soc Lond B Biol Sci ; 374(1770): 20180114, 2019 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-30966878

RESUMO

Kin selection theory defines the conditions for which altruism or 'helping' can be favoured by natural selection. Tests of this theory in cooperatively breeding animals have focused on the short-term benefits to the recipients of help, such as improved growth or survival to adulthood. However, research on early-life effects suggests that there may be more durable, lifelong fitness impacts to the recipients of help, which in theory should strengthen selection for helping. Here, we show in cooperatively breeding banded mongooses ( Mungos mungo) that care received in the first 3 months of life has lifelong fitness benefits for both male and female recipients. In this species, adult helpers called 'escorts' form exclusive one-to-one caring relationships with specific pups (not their own offspring), allowing us to isolate the effects of being escorted on later reproduction and survival. Pups that were more closely escorted were heavier at sexual maturity, which was associated with higher lifetime reproductive success for both sexes. Moreover, for female offspring, lifetime reproductive success increased with the level of escorting received per se, over and above any effect on body mass. Our results suggest that early-life social care has durable benefits to offspring of both sexes in this species. Given the well-established developmental effects of early-life care in laboratory animals and humans, we suggest that similar effects are likely to be widespread in social animals more generally. We discuss some of the implications of durable fitness benefits for the evolution of intergenerational helping in cooperative animal societies, including humans. This article is part of the theme issue 'Developing differences: early-life effects and evolutionary medicine'.


Assuntos
Comportamento de Ajuda , Herpestidae/fisiologia , Longevidade , Reprodução , Animais , Comportamento Cooperativo , Feminino , Herpestidae/crescimento & desenvolvimento , Masculino
11.
Proc Biol Sci ; 286(1896): 20190033, 2019 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-30963932

RESUMO

Dispersal is a key process influencing the dynamics of socially and spatially structured populations. Dispersal success is determined by the state of individuals at emigration and the costs incurred after emigration. However, quantification of such costs is often difficult, due to logistical constraints of following wide-ranging individuals. We investigated the effects of dispersal on individual body mass and stress hormone levels in a cooperative breeder, the meerkat ( Suricata suricatta). We measured body mass and faecal glucocorticoid metabolite (fGCM) concentrations from 95 dispersing females in 65 coalitions through the entire dispersal process. Females that successfully settled lost body mass, while females that did not settle but returned to their natal group after a short period of time did not. Furthermore, dispersing females had higher fGCM levels than resident females, and this was especially pronounced during the later stages of dispersal. By adding information on the transient stage of dispersal and by comparing dispersers that successfully settled to dispersers that returned to their natal group, we expand on previous studies focusing on the earlier stages of dispersal. We propose that body mass and stress hormone levels are good indicators to investigate dispersal costs, as these traits often play an important role in mediating the effects of the environment on other life-history events and individual fitness.


Assuntos
Distribuição Animal/fisiologia , Peso Corporal , Herpestidae/fisiologia , Estresse Fisiológico , Migração Animal/fisiologia , Animais , Fezes/química , Feminino , Glucocorticoides/metabolismo , Comportamento Social , África do Sul
12.
Physiol Behav ; 202: 69-76, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30726721

RESUMO

Meerkats (Suricata suricatta) are known to strongly rely on chemical signals for social communication. However, little is known about their use of the sense of smell in foraging and food detection. The aim of the present study was therefore to assess whether captive meerkats are able to (1) detect hidden food using olfactory cues alone, (2) discriminate between the odor of real food and a single food odor component, and (3) build an association between the odor of real food and a novel odor. We employed the buried food test, widely used with rodents to assess basic olfactory abilities and designed to take advantage of the propensity of certain species to dig. We found that the meerkats were clearly able to find all four food types tested (mouse, chicken, mealworm, banana) using olfactory cues alone and that they successfully discriminated between the odor of real food (banana) and a food odor component (iso-pentyl acetate). In both tasks, the animals dug in the food-bearing corner of the test arena as the first one significantly more often than in the other three corners. No significant association-building between a food odor and a novel odor was found within the 60 trials performed per animal. We conclude that meerkats are able to use olfactory cues when foraging for hidden food. Further, we conclude that the buried food test, employed for the first time with a non-rodent species, is a useful means of assessing basic olfactory capabilities in meerkats.


Assuntos
Comportamento Apetitivo/fisiologia , Herpestidae/fisiologia , Olfato/fisiologia , Animais , Sinais (Psicologia) , Discriminação Psicológica/fisiologia , Feminino , Alimentos , Herpestidae/psicologia , Masculino , Odorantes
13.
Science ; 363(6427): 631-635, 2019 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-30733418

RESUMO

Species in extreme habitats increasingly face changes in seasonal climate, but the demographic mechanisms through which these changes affect population persistence remain unknown. We investigated how changes in seasonal rainfall and temperature influence vital rates and viability of an arid environment specialist, the Kalahari meerkat, through effects on body mass. We show that climate change-induced reduction in adult mass in the prebreeding season would decrease fecundity during the breeding season and increase extinction risk, particularly at low population densities. In contrast, a warmer nonbreeding season resulting in increased mass and survival would buffer negative effects of reduced rainfall during the breeding season, ensuring persistence. Because most ecosystems undergo seasonal climate variations, a full understanding of species vulnerability to global change relies on linking seasonal trait and population dynamics.


Assuntos
Adaptação Fisiológica , Ambientes Extremos , Fertilidade , Herpestidae/fisiologia , Animais , Botsuana , Mudança Climática , Feminino , Masculino , Densidade Demográfica , Dinâmica Populacional , Chuva , Estações do Ano , Temperatura
14.
Toxicol Ind Health ; 35(2): 145-158, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30654724

RESUMO

The populations of wild animals are declining in many parts of the world in response to man-made alterations in the environment. Environmental contamination due to heavy metals discharge from industry may contribute to the decline of wild animal populations by impacting their reproduction, growth, and development. In the leather tanning industry, chromium (Cr) is used as a basic component, but it is a potent toxicant that can affect many of the physiological functions of animals. In the current study, we investigated the reproductive toxicity of industrial Cr in female small Indian mongooses inhabiting a tannery area. Adult female specimens were live trapped from February 2015 to January 2016. Blood and other body tissues (ovaries, kidneys and liver) of the captured specimens were collected along with soil and water samples from the environment for analysis. The Cr concentrations were found significantly ( p < 0.0001) increased compared to control in the environment, blood, and all body tissues of the animals. Estradiol and progesterone levels were found to be significantly decreased in comparison with control ( p < 0.0001), along with reduced ovarian weights, while follicle stimulating hormone (FSH) and luteinizing hormone levels were found significantly ( p < 0.0001) elevated. Light microscopy revealed significantly decreased in comparison with control ovarian follicle numbers ( p < 0.0001) and diameters, vacuolization of the oocytes, and a significantly higher percentage of atretic follicles inside the ovary. We conclude that Cr discharged from the tanneries is absorbed by the exposed female small Indian mongoose, leading to ovarian dysfunction with potential impairment of reproductive function.


Assuntos
Cromo/toxicidade , Poluição Ambiental/efeitos adversos , Herpestidae/fisiologia , Folículo Ovariano , Curtume , Animais , Peso Corporal/efeitos dos fármacos , Cromo/análise , Cromo/farmacocinética , Feminino , Folículo Ovariano/efeitos dos fármacos , Folículo Ovariano/patologia , Paquistão , Progesterona/sangue , Distribuição Tecidual
15.
Curr Biol ; 28(22): 3661-3666.e3, 2018 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-30416063

RESUMO

Coordination is a fundamental aspect of social living, underlying processes ranging from the maintenance of group cohesion to the avoidance of competition. Coordination can manifest as synchronization, where individuals perform the same action at the same time but can also take the form of anti-synchronization or turn-taking. Turn-taking has mainly been studied in the context of the development of language [1] due to the fact that it is a universal feature in all languages and has been found to appear early in infancy [2, 3]. Recently, turn-taking has received attention in animal communication research [4-7] as a potential foundation on which social communication was formed [1, 3]. In this study, we describe turn-taking in group-wide vocal interactions of meerkats (Suricata suricatta) during low-conflict sunning behavior, which is accompanied by the production of specific "sunning calls." We show that sunning-call production is socially stimulated and that at the group level, meerkats avoid overlap, thus fulfilling a key principle of turn-taking [8]. Through observational data and playback experiments, we show that these group-level patterns arise from two individual-level rules: call inhibition over short timescales, which prevents mutual interference, and call excitation over longer timescales, which stimulates further group calling. These simple rules suggest that hierarchy formation and turn allocation are not required for achieving group-wide coordination of communication. We also suggest that the potential bonding function of turn-taking shown in humans might have similar effects in animal interactions. VIDEO ABSTRACT.


Assuntos
Herpestidae/fisiologia , Comportamento Social , Vocalização Animal , Animais , Comportamento Animal
16.
Curr Biol ; 28(18): 2934-2939.e4, 2018 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-30174185

RESUMO

In many cooperatively breeding animal societies, breeders outlive non-breeding subordinates, despite investing heavily in reproduction [1-3]. In eusocial insects, the extended lifespans of breeders arise from specialized slowed aging profiles [1], prompting suggestions that reproduction and dominance similarly defer aging in cooperatively breeding vertebrates, too [4-6]. Although lacking the permanent castes of eusocial insects, breeders of vertebrate societies could delay aging via phenotypic plasticity (similar rank-related changes occur in growth, neuroendocrinology, and behavior [7-10]), and such plastic deferment of aging may reveal novel targets for preventing aging-related diseases [11]. Here, we investigate whether breeding dominants exhibit extended longevity and delayed age-related physiological declines in wild cooperatively breeding meerkats. We show that dominants outlive subordinates but exhibit faster telomere attrition (a marker of cellular senescence and hallmark of aging [12]) and that in dominants (but not subordinates), rapid telomere attrition is associated with mortality. Our findings further suggest that, rather than resulting from specialized aging profiles, differences in longevity between dominants and subordinates are driven by subordinate dispersal forays, which become exponentially more frequent with age and increase subordinate mortality. These results highlight the need to critically examine the causes of rank-related longevity contrasts in other cooperatively breeding vertebrates, including social mole-rats, where they are currently attributed to specialized aging profiles in dominants [4].


Assuntos
Herpestidae/fisiologia , Longevidade/fisiologia , Predomínio Social , Encurtamento do Telômero/fisiologia , Animais , Feminino , Herpestidae/genética , Hierarquia Social , Masculino , Comportamento Sexual Animal
17.
PLoS One ; 13(6): e0198277, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29897948

RESUMO

Wildlife activity patterns tend to be defined by terms such as diurnal and nocturnal that might not fully depict the complexity of a species' life history strategy and behavior in a given system. These activity pattern categories often influence the methodological approaches employed, including the temporal period of study (daylight or nighttime). We evaluated banded mongoose (Mungos mungo) behavior in Northern Botswana through the use of remote sensing cameras at active den sites in order to characterize early morning behavior for this diurnal species. Our approach, however, provided the facility to capture unexpected nocturnal activity in a species that had otherwise only been studied during daylight hours. Camera traps were deployed for 215 trap days (24 hour data capture period) at den sites, capturing 5,472 photos over all events. Nocturnal activity was identified in 3% of trap days at study den sites with both vigilant and non-vigilant nocturnal behaviors identified. While vigilant behaviors involved troop fleeing responses, observations of non-vigilant behaviors suggest nonresident mongoose may investigate den sites of other troops during nocturnal time periods. There was no association between the occurrence of nocturnal activity and lunar phase (Fisher's exact test, n = 215, p = 0.638) and thus, increased moonlight was not identified as a factor influencing nocturnal behavior. The drivers and fitness consequences of these nocturnal activities remain uncertain and present intriguing areas for future research. Our findings highlight the need for ecological studies to more explicitly address and evaluate the potential for temporal variability in activity periods. Modifying our approach and embracing variation in wildlife activity patterns might provide new insights into the interaction between ecological phenomenon and species biology that spans the diurnal-nocturnal spectrum.


Assuntos
Comportamento Animal/fisiologia , Herpestidae/fisiologia , Animais , Animais Selvagens , Botsuana , Ritmo Circadiano , Lua , Tecnologia de Sensoriamento Remoto
18.
Proc Natl Acad Sci U S A ; 115(24): 6255-6260, 2018 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-29844179

RESUMO

Many animals participate in biological markets, with strong evidence existing for immediate cooperative trades. In particular, grooming is often exchanged for itself or other commodities, such as coalitionary support or access to food and mates. More contentious is the possibility that nonhuman animals can rely on memories of recent events, providing contingent cooperation even when there is a temporal delay between two cooperative acts. Here we provide experimental evidence of delayed cross-commodity grooming exchange in wild dwarf mongooses (Helogale parvula). First, we use natural observations and social-network analyses to demonstrate a positive link between grooming and sentinel behavior (acting as a raised guard). Group members who contributed more to sentinel behavior received more grooming and had a better social-network position. We then used a field-based playback experiment to test a causal link between contributions to sentinel behavior and grooming received later in the day. During 3-h trial sessions, the perceived sentinel contributions of a focal individual were either up-regulated (playback of its surveillance calls, which are given naturally during sentinel bouts) or unmanipulated (playback of its foraging close calls as a control). On returning to the sleeping refuge at the end of the day, focal individuals received more grooming following surveillance-call playback than control-call playback and more grooming than a matched individual whose sentinel contributions were not up-regulated. We believe our study therefore provides experimental evidence of delayed contingent cooperation in a wild nonprimate species.


Assuntos
Herpestidae/fisiologia , Animais , Feminino , Asseio Animal/fisiologia , Relações Interpessoais , Masculino , Memória/fisiologia , Comportamento Social , Vocalização Animal
19.
Mol Ecol ; 27(9): 2271-2288, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29603504

RESUMO

Inbreeding depression, the reduced fitness of offspring of closely related parents, is commonplace in both captive and wild populations and has important consequences for conservation and mating system evolution. However, because of the difficulty of collecting pedigree and life-history data from wild populations, relatively few studies have been able to compare inbreeding depression for traits at different points in the life cycle. Moreover, pedigrees give the expected proportion of the genome that is identical by descent (IBDg ) whereas in theory with enough molecular markers realized IBDg can be quantified directly. We therefore investigated inbreeding depression for multiple life-history traits in a wild population of banded mongooses using pedigree-based inbreeding coefficients (fped ) and standardized multilocus heterozygosity (sMLH) measured at 35-43 microsatellites. Within an information theoretic framework, we evaluated support for either fped or sMLH as inbreeding terms and used sequential regression to determine whether the residuals of sMLH on fped explain fitness variation above and beyond fped . We found no evidence of inbreeding depression for survival, either before or after nutritional independence. By contrast, inbreeding was negatively associated with two quality-related traits, yearling body mass and annual male reproductive success. Yearling body mass was associated with fped but not sMLH, while male annual reproductive success was best explained by both fped and residual sMLH. Thus, our study not only uncovers variation in the extent to which different traits show inbreeding depression, but also reveals trait-specific differences in the ability of pedigrees and molecular markers to explain fitness variation and suggests that for certain traits, genetic markers may capture variation in realized IBDg above and beyond the pedigree expectation.


Assuntos
Herpestidae/genética , Depressão por Endogamia , Animais , Conservação dos Recursos Naturais , Marcadores Genéticos , Genótipo , Herpestidae/fisiologia , Longevidade/genética , Repetições de Microssatélites , Linhagem
20.
J Anim Ecol ; 87(3): 838-849, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29344939

RESUMO

Dispersal is a key process governing the dynamics of socially and spatially structured populations and involves three distinct stages: emigration, transience and settlement. At each stage, individuals have to make movement decisions, which are influenced by social, environmental and individual factors. Yet, a comprehensive understanding of the drivers that influence such decisions is still lacking, particularly for the transient stage during which free-living individuals are inherently difficult to follow. Social circumstances such as the likelihood of encountering conspecifics can be expected to strongly affects decision-making during dispersal, particularly in territorial species where encounters with resident conspecifics are antagonistic. Here, we analysed the movement trajectories of 47 dispersing coalitions of Kalahari meerkats Suricata suricatta through a landscape occupied by constantly monitored resident groups, while simultaneously taking into account environmental and individual characteristics. We used GPS locations collected on resident groups to create a georeferenced social landscape representing the likelihood of encountering resident groups. We used a step-selection function to infer the effect of social, environmental and individual covariates on habitat selection during dispersal. Finally, we created a temporal mismatch between the social landscape and the dispersal event of interest to identify the temporal scale at which dispersers perceive the social landscape. Including information about the social landscape considerably improved our representation of the dispersal trajectory compared to analyses that only accounted for environmental variables. The latter were only marginally selected or avoided by dispersers. Before leaving their natal territory, dispersers selected areas frequently used by their natal group. In contrast, after leaving their natal territory, they selectively used areas where they were less likely to encounter unrelated groups. This pattern was particularly marked in larger dispersing coalitions and when unrelated males were part of the dispersing coalition. Our results suggest that, in socially and spatially structured species, dispersers gather and process social information during dispersal, and that reducing risk of aggression from unrelated resident groups outweighs benefits derived from conspecific attraction. Finally, our work underlines the intimate link between the social structure of a population and dispersal, which affect each other reciprocally.


Assuntos
Distribuição Animal , Ecossistema , Herpestidae/fisiologia , Comportamento Social , Animais , Feminino , Masculino , Modelos Biológicos , Dinâmica Populacional , África do Sul
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