Behavioral Ecology and Sociobiology最新文献

{"title":"Daily ranging and den usage patterns structure the spatiotemporal properties of social encounters in spotted hyenas","authors":"","doi":"10.1007/s00265-024-03458-3","DOIUrl":"https://doi.org/10.1007/s00265-024-03458-3","url":null,"abstract":"<h3>Abstract</h3> <p>Fission–fusion dynamics describe the tendency for members of some animal societies to associate in subgroups that change size and structure fluidly over time. These dynamics shape social complexity and social structure, but are difficult to study because they unfold simultaneously over large spatial scales. Here we use simultaneous, fine-scale GPS data from spotted hyenas to examine fission–fusion dynamics through a dyadic analysis of <em>merge-split events</em> between pairs of individuals. We introduce a species-agnostic framework for identifying merge-split events and discretizing them into three phases (merging, together, and splitting), enabling analysis of each phase as well as the connections among phases. Applying this framework to the hyena data, we examine the temporal and spatial properties of merges and splits between dyads and test the extent to which social encounters are driven by key locations. Specifically, we focus on communal dens—shelters for juvenile hyenas where classical observational studies often report large aggregations of adults. We find that overall, 62% of merges occurred at communal dens, supporting the idea that dens facilitate meet-ups and subsequent social behavior. Social encounters most commonly involved close approaches within a few meters between hyenas, while co-travel together occurred in only 11% of events. Comparison to permutation-based reference models suggests that independent movement decisions structure broad-scale patterns of social encounters but do not explain the fine-scale dynamics of interactions that unfold during these encounters. We reflect on how physical features such as dens can become social hotspots, causing social and spatial processes to become fundamentally intertwined.</p>","PeriodicalId":8881,"journal":{"name":"Behavioral Ecology and Sociobiology","volume":"44 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140581094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geographic variation and discrimination of social calls in male great himalayan leaf-nosed bats: do functionally similar calls have similar patterns?","authors":"Chunmian Zhang, Ziqi Zheng, Jeffrey R. Lucas, Jiang Feng, Congnan Sun, Tinglei Jiang","doi":"10.1007/s00265-024-03459-2","DOIUrl":"https://doi.org/10.1007/s00265-024-03459-2","url":null,"abstract":"<p>Geographical variation in animals’ acoustic signals has received much attention. However, few studies have compared the patterns and underlying selective forces driving geographical divergence of vocalizations with similar and different functions within the same species. Also, the social consequences of geographical divergence in acoustic signals are still rather poorly understood. Here we recorded three types of social calls of male great Himalayan leaf-nosed bats (<i>Hipposideros armiger</i>) across eight colonies in China. Two calls share similar functions and the third has a function distinct from the other two. We examined the patterns and causes of geographical variation of each of these calls. We found that all three calls had significant geographic variation with similar patterns of spatial variation. Only one of the two social calls with similar functions was found to be affected by genetic drift, while the other two calls were not affected by selection, drift, or morphological constraints. Furthermore, we found that bats could discriminate between vocalizations of their own colony and those of an allopatric colony. Overall, these results suggest that acoustic signals with similar functions may be shaped by different driving forces and acoustic signals with different functions may exhibit similar geographical patterns. This study expands our limited knowledge of the patterns of geographical variation of vocalizations emitted at different emotional states and highlights the importance of comparing simultaneously patterns and causes of geographical divergence of vocalizations with similar and different functions.</p>","PeriodicalId":8881,"journal":{"name":"Behavioral Ecology and Sociobiology","volume":"13 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140313850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Background contrast affects detection and recognition of courting wolf spiders by intended and unintended receivers","authors":"George W. Uetz, Rachel Gilbert, Rebecca Wilson, Jacqueline Mann, Joseph Macedonia, David L. Clark","doi":"10.1007/s00265-024-03453-8","DOIUrl":"https://doi.org/10.1007/s00265-024-03453-8","url":null,"abstract":"<p>We used video playback of courting male <i>Schizocosa ocreata</i> wolf spiders to examine responses of intended receivers (conspecific females) and eavesdroppers (competitor males, predatory spiders, toads) to manipulations of spider color (natural color, monochromatic gray, monochromatic RBG average) displayed against complex leaf litter backgrounds (color, grayscale). Models of chromatic and achromatic contrast between spider stimuli and backgrounds were used to predict receiver responses. The results support the hypothesis that interactions between spider and background coloration affect detection and recognition, although responses varied with receiver type. Detection responses of intended receivers (female <i>S. ocreata</i>) did not fit predictions of the chromatic contrast model in some cases, but showed a fair fit to the achromatic model. Detection responses of social eavesdroppers (male <i>S. ocreata</i>) fit the chromatic and achromatic contrast models slightly better than did female responses (poor fit and very good fit, respectively). Eavesdropping wolf spider predators (<i>Rabidosa</i>) exhibited detection responses that significantly matched predictions of the chromatic (very good fit) and achromatic (excellent fit) models. Whereas jumping spiders (<i>Phidippus</i>) showed a good fit to the chromatic and achromatic contrast models, toad predators had a good fit only to the chromatic model. Recognition responses revealed a different pattern of fit to the chromatic and achromatic models across receiver types, although <i>Rabidosa</i> again indicated a significant fit to both models. Taken together, the results of this study identify both chromatic and achromatic features of spider appearance as likely explanations for differences in behavioral responses of intended and unintended receivers. This outcome suggests the possibility that both sexual and natural selection likely target different features of male appearance during courtship.</p>","PeriodicalId":8881,"journal":{"name":"Behavioral Ecology and Sociobiology","volume":"31 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140199737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vocal and genetic variation between a land-bridge island and mainland populations of the Black-crowned Antshrike (Thamnophilus atrinucha)","authors":"","doi":"10.1007/s00265-024-03455-6","DOIUrl":"https://doi.org/10.1007/s00265-024-03455-6","url":null,"abstract":"<span> <h3>Abstract</h3> <p>Island-mainland systems serve as natural laboratories for studying communication signals. We explored potential divergence in the song of the black-crowned antshrike between Gorgona Island, a land-bridge island off the Pacific coast of Colombia, and several mainland populations. We found that the perching song of this species, the so called loudsong, was distinctly different on Gorgona Island. This differentiation encompassed an increase in frequency bandwidth, a decrease in vocal performance, and a reduction in song duration. All are consistent with documented patterns of divergence observed in avian acoustic signals on oceanic islands. The observed distinctions in loudsong acoustics, including variations in frequency and temporal features, led to the inference that the population on Gorgona Island produces the least complex loudsong dialect across the entire species range. This pattern of how an innate vocalization manifests within a land-bridge island, which was connected to the mainland not long ago, lends support to the Character Release Hypothesis. To ensure an unbiased comparison, we considered genetic clusters and analyzed them by comparing ten acoustic signals between the land-bridge island and several mainland populations. Combined with the gene genealogy, this finding supports the validity of two geographic forms: <em>Thamnophilus atrinucha atrinucha</em> and <em>Thamnophilus atrinucha gorgonae</em> (island). However, they also reveal the existence of additional unrecognized dialects of loudsong that transcend current taxonomic classifications. We provide evidence that challenges the long-standing presumption suggesting minimal intraspecific geographic variation in the vocalization among non-vocal learning species.</p> </span> <span> <h3>Significance statement</h3> <p>Significant evolutionary implications exist for an intriguing pattern of variation of the loudsong behavior in the Black-crowned Antshrike over a land-bridge island. Our gene tree does provide evidence of the enormous haplotypic diversity accumulated in the <em>trans</em>-Andean region long after the final uplift of the northern Andes. The acoustic divergence of the loudsong suggests substantial geographic variation within a non-vocal learning suboscine. Genetic and loudsong divergence on a land-bridge island add to document that evolution of acoustic traits may be relaxed in islands as compared to those observed on the species-rich mainland. The island-mainland system is one of the few definitive biogeographic contexts for understanding evolution of acoustic behavior.</p> </span>","PeriodicalId":8881,"journal":{"name":"Behavioral Ecology and Sociobiology","volume":"229 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140205580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Iberian wolf’s diet and its quality during breeding season: exploring the influence of zone, wolf groups, prey availability and individual factors","authors":"Isabel Barja, Ana Piñeiro, Javier Talegón, Aritz Ruiz-González, Álvaro Navarro-Castilla, Amaia Caro, Toni Gago-Barja, M. Carmen Hernández","doi":"10.1007/s00265-024-03457-4","DOIUrl":"https://doi.org/10.1007/s00265-024-03457-4","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Large predators are essential in maintaining ecosystem functioning, and comprehending how their feeding habits change across natural and human-dominated landscapes is crucial to preserve biodiversity. In this study, the diet of Iberian wolves (<i>Canis lupus signatus</i>) during pup rearing season (July to September) has been studied in relation to prey abundance and putting emphasis in the analysis of the differences between zones, wolf groups and individual factors (age, sex and social status). For this, non-invasive monitoring was carried out in three zones of Spain where nine different wolf breeding groups were detected (Galicia, <i>n</i> = 4; Zamora, <i>n</i> = 4 and Valladolid, <i>n</i> = 1). Faecal samples were collected near breeding sites for dietary and genetic analyses, registering if it was or not a scent mark to know the social status of the individuals. Prey availability was determined by camera trapping or requesting the official census of wild prey in the study areas. We found differences in wolf’s diet depending on the zone and the breeding group however, the diet did not vary depending on the age, sex and social status. In general, Iberian wolves mainly fed on wild ungulates (wild boar, roe deer and red deer), feeding on the most abundant prey, except for Baldriz group in Galicia which seems to be specialized in hunting roe deer. Domestic animals’ consumption (sheep, goat, donkey, pig) was not high, but it occurred specially in agriculture and livestock areas (Ferreras in Zamora and Valladolid) where wild prey were less available.</p><h3 data-test=\"abstract-sub-heading\">Significance statement</h3><p>In this study, we shed light on the vital role of Iberian wolves in the ecosystem by investigating the dietary preferences during pup rearing season across different landscapes. Our research revealed differences in wolf diets based on geographic location and breeding groups, emphasizing their adaptability. We found that age, sex, and social status did not significantly influence their dietary preferences. Iberian wolves predominantly target wild ungulates, except for a specialized group in Galicia. Our study introduces a novel approach as it is the first to analyse wolf diet based on individual factors and using nitrogen analysis. Additionally, the study highlights previously overlooked dietary patterns of the Iberian wolf subspecies, despite its critical role in the ecosystem as a top predator. Furthermore, we emphasize the necessity of conserving wild ungulate populations to reduce livestock attacks by ensuring a stable supply of wild prey, promoting coexistence between humans and wolves.</p>","PeriodicalId":8881,"journal":{"name":"Behavioral Ecology and Sociobiology","volume":"183 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140199702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The relationship between preference and switching in flower foraging by bees","authors":"Daniel R. Papaj, Avery L. Russell","doi":"10.1007/s00265-024-03456-5","DOIUrl":"https://doi.org/10.1007/s00265-024-03456-5","url":null,"abstract":"<p>It seems self-evident that generalist foragers switch more between resources than specialists but despite diverse ecological and evolutionary implications, how variation in switching relates to variation in preference warrants additional study. Here we tested predictions based on a simple probability model, using flower-foraging bees as a model system. In laboratory assays, we presented bumble bee (<i>Bombus impatiens</i>) workers with flowers of two species, <i>Tecoma stans</i> and <i>T. alata</i>, from which they could collect nectar and/or pollen. We quantified landing preference and occurrence of switching between species in successive visits. Bees varied greatly in floral preference. Almost half showed statistically significant preferences for one or the other species, while the rest were generalists in preference. As expected, generalists using both flower species switched more in successive visits than bees that were more specialized, a pattern fit to a quadratic function. However, generalist individuals switched more than expected based on null expectation. A Modified Jacob’s Index (MJI) of switching was significantly positively correlated with degree of preference: generalist bees had more negative MJI’s than specialist bees, indicating that even after the expected statistical effect of preference on switching was accounted for, they switched more than specialists. A simulation ruled out the possibility that the pattern was due to bias in MJI. Generalist-specialist differences in which food was collected (nectar versus pollen) were also ruled out. We offer possible explanations for our observed pattern and advocate consideration of preference and switching throughout behavioral ecology.</p>","PeriodicalId":8881,"journal":{"name":"Behavioral Ecology and Sociobiology","volume":"18 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140166994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanisms for polyandry evolution in a complex social bee","authors":"Keith Delaplane, Katherine Hagan, Kevin Vogel, Lewis Bartlett","doi":"10.1007/s00265-024-03450-x","DOIUrl":"https://doi.org/10.1007/s00265-024-03450-x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Polyandry in social Hymenoptera is associated with reduced within-colony relatedness and increased colony-level ecologic fitness. One explanation for this sees increasing within-nest genetic diversity as a mechanism for improving group task efficiency and colony competitiveness. A queen on her mating flight captures nearly 90% of her breeding population’s allele potential by her tenth effective mating (<i>m</i>_<i>e</i> ~ 10 males). Under this population allele capture (PAC) model, colony fitness gains track mating number in an asymptotic manner, leveling out after about the tenth mating. A supporting theory we call the genotype composition (GC) model sees genetic novelty at mating levels higher than the <i>m</i>_<i>e</i> ~ 10 asymptote, the hyperpolyandry zone, resulting from unique genotype compositions whose number are potentially infinite. Colony fitness gains under the GC model will track mating number in a linear manner. We set up field colonies with <i>Apis mellifera</i> queens each instrumentally mated with 1, 2, 4, 8, 16, or 32 males, creating a polyandry gradient bracketing the qualitative divide of <i>m</i>_<i>e</i> ~ 10, measured tokens of colony level fitness, and collected observation hive data. Our results lead us to conclude that (1) ancestral colony traits fundamental to eusociality (cooperative brood care) respond to mating level changes at or below <i>m</i>_<i>e</i> ~ 10 in a manner consistent with the PAC model, whereas (2) more derived specialized colony phenotypes (resistance to the non-native parasite <i>Varroa destructor</i>) continue improving with increasing <i>m</i>_<i>e</i> in a manner consistent with the GC model. By either model, (3) the mechanism for increasing colony fitness is an increase in worker task specialisms and task efficiency.</p><h3 data-test=\"abstract-sub-heading\">Significance statement</h3><p>Polyandry is a female’s practice of mating with many males, storing their sperm, and using it to produce genetically diverse offspring. In complex social bees, a queen captures nearly 90% of her breeding population’s diversity potential by her tenth mating; however, queens in nature routinely mate with many more than ten males. We tested two models that, together, explain how social bee colonies ecologically benefit from queen mating numbers ranging from 2 to potential infinity. A population allele capture (PAC) model focuses on colony fitness gains at mating numbers at or below 10, and we provide evidence that it was at these polyandry levels that significant gains were made in an ancestral eusocial trait, cooperative brood care. A genotype composition (GC) model focuses on colony fitness gains at higher mating numbers, and we believe these gains are centered around more recently evolved ecologic specialisms such as parasite resistance.</p>","PeriodicalId":8881,"journal":{"name":"Behavioral Ecology and Sociobiology","volume":"40 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140075460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance and efficiency in leaf transport: unveiling the task allocation puzzle in Acromyrmex subterraneus","authors":"Antônio Marcos Oliveira Toledo, Arthur Zimerer, Juliane Floriano Santos Lopes","doi":"10.1007/s00265-024-03454-7","DOIUrl":"https://doi.org/10.1007/s00265-024-03454-7","url":null,"abstract":"<p>The performance of ant workers in a given task can be highly variable, generating a non-homogenous workload in the colony. However, there is no information on whether high performance workers are more efficient, or have any morphometric and physiological variation that causes them to both start earlier and continue executing the task longer. Here, we demonstrate that non-homogeneous task distribution is common in small colonies and that different performance levels occur even among <i>Acromyrmex subterraneus</i> workers of the same size class. High Activity workers did more work and were faster, so they were more efficient than Low Activity workers. However, their efficiency was not related to their leg length, as it was for Low Activity workers. Also, the delay of the first loaded trip of High Activity workers was shorter than that of Low Activity workers, indicating an earlier response of the former to the task. Delay variation was not affected by mass-specific metabolic rate. Considering the first five trips, we found that the first trip had a longer duration than the others, and High Activity workers were faster than Low Activity workers, suggesting that the higher efficiency of High Activity workers may be related to the reinforcement mechanism, which in turn lessens their response threshold to the task. Finally, workers had similar mandible morphometry (length of the first and second tooth, number of teeth), and body mass components (water content, lean dry weight and lipid content) despite their activity category, indicating that these variables did not explain differences in performance or efficiency among workers. The hypometric mass scaling metabolic rate showed that Non-transporters had proportionally lower energy expenditure than other categories. High Activity workers showed remarkable performance, efficiency, and faster responses to foraging stimulus. We suggest that this heightened level of individual proficiency is in line with the threshold model, explaining the operation of the task allocation mechanism within the same worker size class.</p>","PeriodicalId":8881,"journal":{"name":"Behavioral Ecology and Sociobiology","volume":"20 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140076270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"‘Beware, I am large and dangerous’ – human listeners can be deceived by dynamic manipulation of the indexical content of agonistic dog growls","authors":"Péter Pongrácz, Petra Dobos, Borbála Zsilák, Tamás Faragó, Bence Ferdinandy","doi":"10.1007/s00265-024-03452-9","DOIUrl":"https://doi.org/10.1007/s00265-024-03452-9","url":null,"abstract":"<p>Dishonest vocal signals about body size are rarely encountered, however, dogs are capable of modifying indexical information in their growls. This apparent acoustic body-size manipulation could be affected by the level of threat experienced by the dog. We tested whether this natural size manipulation actually affects how listeners assess the size of the dog, thus whether it could be considered as a successful indexical information manipulation. We requested human participants to assess dog growls, originally recorded when dogs encountered various ‘threatening strangers’ (of different sex, stature). The participants heard several sets of growl pairs, where they had to guess, which growl belonged to the ‘larger dog’. In the Control condition, dog growls originated from two different dogs in a pair; in the Test condition, growls of the same dog were presented pair by pair, always recorded in the presence of different threatening humans. Human listeners reliably picked the larger dog from two differently sized animals based on their growls alone. In the Test condition, participants thought that the dog was ‘larger’ when it was threatened by a female experimenter, and when the dog was growling at a larger sized human. We found that while growl length modulation was the main factor behind size-choice decisions in the case of female strangers, formant dispersion difference contributed the most when listeners chose which dog was the larger in the case of male opponents. Our results provide firsthand evidence of dogs’ functionally deceptive vocalizations towards humans, a phenomenon which has not been shown before in any interspecific scenario.</p>","PeriodicalId":8881,"journal":{"name":"Behavioral Ecology and Sociobiology","volume":"79 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140005402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Competitive asymmetries, birthing asynchrony and sibling rivalry in a social lizard","authors":"Alix Bouffet-Halle, Erik Wapstra, Geoffrey M. While","doi":"10.1007/s00265-024-03442-x","DOIUrl":"https://doi.org/10.1007/s00265-024-03442-x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Family life often involves interactions between individuals who have different fitness goals, leading to conflict. Resolution of this conflict is key for the stabilisation of family life. Here, we used a lizard, <i>Liopholis whitii</i>, that lives in facultative family groups to characterise the nature and extent of sibling conflict and test the role that individual and litter characteristics play in shaping conflict between family members. We found significant variation in conflict between family groups, specifically in relation to siblings. In approximately half of the litters, siblings were aggressive towards one another, while in the other half of litters, there was no aggression observed between siblings. There were no differences between aggressive and non-aggressive litters in the key factors predicted to mediate conflict, including sex, offspring size, or litter size. However, in aggressive litters, the maximum amount of within-litter conflict decreased with an increase in the spread between births of siblings. First-born offspring were significantly more likely to be aggressive towards their siblings compared to second and third born offspring. While one offspring was usually the target of that aggression, we found no evidence that any individual-level factor predicted who received aggression. In aggressive litters, aggressive offspring spent a greater amount of time with their mother compared to non-aggressive offspring. Similar asymmetries in the amount of time offspring spent with their mother between siblings were also observed in non-aggressive litters. Combined, our results suggest that birth order is the main driver of sibling conflict in aggressive litters in this facultatively social lizard species, suggesting that birthing asynchrony may provide females with a mechanism to manage conflict.</p><h3 data-test=\"abstract-sub-heading\">Significance statement</h3><p>Conflict is a ubiquitous aspect of family life; it occurs between adults, between parents and offspring as well as between siblings. We show that the extent of conflict between siblings varies considerably within and between families in a lizard that exhibits prolonged associations between parents and offspring. We found no effects of offspring sex or size on within or between litter conflict. Instead, the number of days that passed between the birth of offspring appears to be the main factor that influences how much conflict there is between siblings. Furthermore, birth order was the main factor predicting which offspring was dominant. Combined this suggests that birthing asynchrony, the ability of females to spread out births across multiple days, may play a crucial role in the management of conflict in this system. As the moderation of conflict is crucial for the stabilisation of family life, these results provide important insights into the early evolution of social life.</p>","PeriodicalId":8881,"journal":{"name":"Behavioral Ecology and Sociobiology","volume":"4 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140005225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}