Biology LettersPub Date : 2025-06-01Epub Date: 2025-06-04DOI: 10.1098/rsbl.2025.0010
Barbara C Klump, David Walter, John M Martin, Lucy M Aplin
{"title":"Emergence of a novel drinking innovation in an urban population of sulphur-crested cockatoos, <i>Cacatua galerita</i>.","authors":"Barbara C Klump, David Walter, John M Martin, Lucy M Aplin","doi":"10.1098/rsbl.2025.0010","DOIUrl":"10.1098/rsbl.2025.0010","url":null,"abstract":"<p><p>The spread of innovation has been proposed as a potentially important source of adaptive behavioural responses to anthropogenic change. Yet, while a diversity of urban innovations have been documented in animals, there are relatively few examples of these spreading to form local traditions. One notable example is the 'bin-opening innovation' in sulphur-crested cockatoos (<i>Cacatua galerita</i>), where individuals open household bin lids to access food waste, with this behaviour spreading across southern Sydney, Australia. Here, we describe a second innovation in this species, the 'drinking-fountain innovation'. Individuals from a population in western Sydney drink from twist-handle public drinking fountains, with this behaviour persisting over at least 2 years. Successful operation requires a coordinated sequence of actions, with only 41% of observed attempts ending in success. Intensive observation at one drinking fountain over 44 days revealed 525 attempts and 46% of marked individuals successfully engaging in the behaviour, with individuals visiting at dawn and dusk in line with expectations for use of a water resource. Public drinking fountains vary in design between local councils but are generally widespread. Yet, to our knowledge, this behaviour has not been observed elsewhere. Altogether, this suggests that this drinking innovation has spread to form a new urban-adapted local tradition.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"21 6","pages":"20250010"},"PeriodicalIF":2.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12133349/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144214822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Biology LettersPub Date : 2025-06-01Epub Date: 2025-06-11DOI: 10.1098/rsbl.2025.0099
Thomas Remer
{"title":"Females' scarcity of testosterone: a helper to save somatic resources in unfavourable environments. A Comment on: 'The sexy and formidable male body: men's height and weight are condition-dependent, sexually selected traits' (2025), by Giofrè D <i>et al</i>.","authors":"Thomas Remer","doi":"10.1098/rsbl.2025.0099","DOIUrl":"10.1098/rsbl.2025.0099","url":null,"abstract":"","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"21 6","pages":"20250099"},"PeriodicalIF":2.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12152743/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144265204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Biology LettersPub Date : 2025-06-01Epub Date: 2025-06-18DOI: 10.1098/rsbl.2025.0103
Peter Edmunds, Adrian Cheh, Scott Burgess
{"title":"A physiological crisis drives the coral recruitment bottleneck.","authors":"Peter Edmunds, Adrian Cheh, Scott Burgess","doi":"10.1098/rsbl.2025.0103","DOIUrl":"10.1098/rsbl.2025.0103","url":null,"abstract":"<p><p>Recruitment failure is an important factor contributing to population declines of tropical corals. Because the causes of death for juvenile corals are unclear, it is challenging to predict how recruitment bottlenecks will change in the future. We tested the hypothesis that depletion of metabolic reserves increases mortality of juvenile corals under thermal stress. Metabolic reserves of juvenile colonies (<30 mm diameter) of broadcast spawning <i>Pocillopora</i> from Moorea, French Polynesia, were manipulated using elevated temperature to increase respiration, and reduced day length to decrease photosynthesis, and estimated as biomass. Corals with high or low biomass were incubated at 28°C and 31°C for 15 days. Juvenile <i>P. meandrina</i> with high biomass were six times more likely to die at 31°C versus 28°C, but corals with low biomass were 48 times more likely to die at 31°C versus 28°C. When juvenile <i>Pocillopora</i> were grown in seawater augmented with bicarbonate to reduce the cost of skeletogenesis in support of growth, growth was not affected, but energy expenditure was reduced by 20% to reduce reliance on metabolic reserves. Resource limitation of juvenile corals can affect their response to elevated temperatures, supporting the hypothesis that a physiological crisis initiated by resource limitation mediates the stringency of recruitment bottlenecks.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"21 6","pages":"20250103"},"PeriodicalIF":2.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12173483/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144315861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Biology LettersPub Date : 2025-06-01Epub Date: 2025-06-18DOI: 10.1098/rsbl.2024.0669
Ayumi Ogawa, Shinya Yamamoto
{"title":"Why is mutual grooming rare despite its function? A hypothesis for cognitive constraints.","authors":"Ayumi Ogawa, Shinya Yamamoto","doi":"10.1098/rsbl.2024.0669","DOIUrl":"10.1098/rsbl.2024.0669","url":null,"abstract":"<p><p>Mutual grooming, where both participants groom each other simultaneously, is a type of allogrooming and probably also plays an important role as a social and hygienic function; however, it has attracted little attention, probably due to its rarity compared to prevailing unidirectional grooming in many social animals, such as primate species. While previous studies have shown that mutual grooming has functional significance, such as promoting social bonds and maximizing short-term benefits, we do not know why mutual grooming is much rarer than unidirectional grooming, and its restrictive factors have been mostly uninvestigated. In this article, we propose a hypothesis of cognitive constraints in which cognitive complexity is assumed as an underpinning mechanism for mutual grooming, thereby restricting its prevalence across animal species. To achieve joint action and its symmetric nature, mutual grooming is considered to require behavioural coordination between participants, which could be facilitated by active communication and, furthermore, by joint commitment based on a mutual understanding of intention between the two. The fact that joint commitment has been proved only in a limited number of animals may support this cognitive demand hypothesis, although it definitely calls for further in-depth investigation and comparative studies across primate and non-primate species.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"21 6","pages":"20240669"},"PeriodicalIF":2.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12173481/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144315864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Biology LettersPub Date : 2025-06-01Epub Date: 2025-06-25DOI: 10.1098/rsbl.2024.0636
Colin E Adams, Colin Bean, Kevin Parsons
{"title":"Foraging and thermally induced phenotypic plasticity interact in the most northerly distributed freshwater fish.","authors":"Colin E Adams, Colin Bean, Kevin Parsons","doi":"10.1098/rsbl.2024.0636","DOIUrl":"10.1098/rsbl.2024.0636","url":null,"abstract":"<p><p>Elevated temperatures from climate change are predicted to be more extreme at higher latitudes. This could require phenotypic plasticity to generate variation that allows organisms to persist in these regions. However, climate change will provide a multifactorial change in environmental cues, making an understanding of how they interact essential for predicting persistence and future evolutionary potential. Here, the impacts of temperature on ecologically relevant phenotypic plasticity (foraging environment) in Arctic charr (<i>Salvelinus alpinus</i>) were studied. Eggs and alevins were kept at the same temperature (9°C) and split using a factorial design. This included two temperature treatments (10°C and 14°C) and two treatments representing benthic and pelagic foraging styles. We measured morphology in response to these treatment combinations and found an interaction between foraging and temperature-induced plasticity in body shape that included changes in body depth and the caudal peduncle that could impact swimming ability and fitness. This indicates that thermal conditions may change how plasticity responds to ecological conditions and impact adaptive variation.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"21 6","pages":"20240636"},"PeriodicalIF":2.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12187422/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144483106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Biology LettersPub Date : 2025-06-01Epub Date: 2025-06-04DOI: 10.1098/rsbl.2025.0193
Levi Storks, Jessica Garcia, Christian A Perez-Martinez, Manuel Leal
{"title":"Correction: Habitat complexity influences neuron number in six species of Puerto Rican <i>Anolis</i>.","authors":"Levi Storks, Jessica Garcia, Christian A Perez-Martinez, Manuel Leal","doi":"10.1098/rsbl.2025.0193","DOIUrl":"10.1098/rsbl.2025.0193","url":null,"abstract":"","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"21 6","pages":"20250193"},"PeriodicalIF":2.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12134934/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144214821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Biology LettersPub Date : 2025-06-01Epub Date: 2025-06-06DOI: 10.1098/rsbl.2025.0005
Ritabrata Chowdhury, T Ulmar Grafe, Faizah Metali, Walter Federle
{"title":"Arms race of physical defences: hooked trichomes of <i>Macaranga</i> ant-plants kill lycaenid caterpillars, but one specialist has a counter-defence.","authors":"Ritabrata Chowdhury, T Ulmar Grafe, Faizah Metali, Walter Federle","doi":"10.1098/rsbl.2025.0005","DOIUrl":"10.1098/rsbl.2025.0005","url":null,"abstract":"<p><p>The coevolution of insects and chemical plant defences has been described as an arms race, but it is unclear whether physical plant defences can produce similar outcomes. Here, we report a previously unknown interaction from the mutualism between ants and <i>Macaranga</i> trees. Although <i>Macaranga</i> trees are well protected against herbivory by aggressive ants, caterpillars of the genus <i>Arhopala</i> (Lepidoptera: Lycaenidae) can feed on the leaves by appeasing the ants with nectar-like secretions. One ant-plant species, <i>M. trachyphylla</i>, bears hooked trichomes on its green surfaces. When placed on <i>M. trachyphylla</i> stems or petioles, <i>Arhopala</i> caterpillars associated with other <i>Macaranga</i> species (<i>A. major, A. dajagaka</i> and <i>A. zylda</i>) were quickly arrested by the sharp trichomes that pierced their cuticle, resulting in death by rapid blood loss and removal by ants. In striking contrast, <i>A. amphimuta</i> caterpillars, which occur naturally on <i>M. trachyphylla</i>, could easily walk over the hooked trichomes without any injury. As hooked trichomes are a novel trait within <i>Macaranga</i>, this interaction provides an example of de novo evolution of a physical plant defence, which in turn has been overcome by a specialist herbivore. Our study suggests that physical plant defences can lead to evolutionary arms races similar to those for chemical defences.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"21 6","pages":"20250005"},"PeriodicalIF":2.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12142895/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144233079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Biology LettersPub Date : 2025-06-01Epub Date: 2025-06-11DOI: 10.1098/rsbl.2025.0112
Daniel Hanley, Mark E Hauber, Mandë Holford, Collins Moya, Claire N Spottiswoode, Tanmay Dixit
{"title":"Pigment concentrations only partially predict avian eggshell colour mimicry in a polymorphic host-brood parasite system.","authors":"Daniel Hanley, Mark E Hauber, Mandë Holford, Collins Moya, Claire N Spottiswoode, Tanmay Dixit","doi":"10.1098/rsbl.2025.0112","DOIUrl":"10.1098/rsbl.2025.0112","url":null,"abstract":"<p><p>The precise mimicry of host eggshell colours and patterns by some obligate avian brood parasites provides a powerful study system for understanding co-evolutionary arms races. However, most attention has focused on host behaviour in response to mimicry, rather than the proximate mechanisms that give rise to mimetic eggshell colours and patterns. In Africa, the cuckoo finch <i>Anomalospiza imberbis</i> produces a wide range of eggshell colours that largely match those of one of its hosts, the tawny-flanked prinia <i>Prinia subflava</i>. Here, we use chemical analysis and avian visual modelling to determine how cuckoo finches and prinias produce this wide array of perceived eggshell colours. Although both species incorporate similar proportions of the two main egg pigments (biliverdin and protoporphyrin) into their eggshell matrix, the cuckoo finch deposits greater concentrations of pigments. Proportions of pigments predicted eggshell coloration only in bluer eggshells, whereas there was no statistical relationship between pigments and colours in browner eggshells. Possible explanations include that brown pigments are involved in maculation and/or strengthening the eggshell. Overall, variation in the deposition of eggshell pigments results in complex relationships between eggshell chemistry and avian-perceivable coloration, both within and across species in this system.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"21 6","pages":"20250112"},"PeriodicalIF":2.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12151605/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144265205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Biology LettersPub Date : 2025-06-01Epub Date: 2025-06-25DOI: 10.1098/rsbl.2025.0187
Lewis G Halsey, David Geary
{"title":"The nurture of nature: why physical and psychological differences between the sexes are greater in healthier, wealthier societies.","authors":"Lewis G Halsey, David Geary","doi":"10.1098/rsbl.2025.0187","DOIUrl":"10.1098/rsbl.2025.0187","url":null,"abstract":"<p><p>Men and women differ morphologically, physiologically, cognitively, psychologically and behaviourally, and many of these differences are getting larger. We propose a synthesis of two disparate yet related mechanisms in combination with sexual selection theory to explain this divergence of the sexes. In large part through sexual selection, males and females have evolved many trait differences, some subtle, others stark. In stressful environments (e.g. frequent nutritional shortfalls, disease risk), those differences are attenuated because in the sex where the trait is greater (such as height in men, or various forms of memory in women) the effects of those stressors are more apparent. Societies exposed to these stressors have more restrictive social mores and harsher criminal punishments for norm violations, restricting the behavioural expression of individuals and hence sex-based preferences (e.g. working with people vs. things). It follows that reduction in ecological threats (e.g. pestilence) and out-group social threats (e.g. warfare) leads to a lessening of in-group social restrictions resulting in more self-referential cognitions, emotions and motivations, and through this a fuller expression of individual and thus sex differences in various psychological domains. In this scenario, increases in bodily sex differences, such as height, are predicted to be associated with increases in psychological and behavioural sex differences (e.g. facets of personality). Our model integrates evolutionary and biological processes with social customs and mores-that is, combines nature and nurture-into a cohesive framework to explain historical and cross-cultural variation in the magnitude of many sex differences.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"21 6","pages":"20250187"},"PeriodicalIF":2.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12187407/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144483109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Biology LettersPub Date : 2025-05-01Epub Date: 2025-05-23DOI: 10.1098/rsbl.2024.0715
Tirza M Moerman, Kia Karina Tahmin, Stephen J Coulson, Leif E Loe, René van der Wal
{"title":"Parasite-host contact in the Arctic: dispersal behaviour of infective nematode larvae from Svalbard reindeer faeces.","authors":"Tirza M Moerman, Kia Karina Tahmin, Stephen J Coulson, Leif E Loe, René van der Wal","doi":"10.1098/rsbl.2024.0715","DOIUrl":"10.1098/rsbl.2024.0715","url":null,"abstract":"<p><p>Gastro-intestinal parasitic nematodes are typical pathogens of mammalian herbivores. A key moment of infection by passively ingested nematodes is the contact between infective larvae and the grazing host. Yet, knowledge on dispersal dynamics of larvae infecting wild herbivores in natural environments is limited. We studied the mode and range of lateral larval movement. As study species, we used infective larvae of <i>Ostertagia gruehneri</i>-a parasitic nematode that can negatively affect its host, Svalbard reindeer (<i>Rangifer tarandus platyrhynchus</i>). In the laboratory, reindeer faecal pats containing larvae were introduced onto soil placed either horizontally or on a slope (10°), mimicking the micro-topography of High Arctic tundra. After four weeks, 939 live nematodes were recorded, of which 23% were in the soil, mostly underneath the faecal pat (20%). The remaining 3% that dispersed away from the pat did so in both sloped and flat soil. We conclude that the larvae were able to actively move from faeces to soil and that subsequent dispersal was limited and not assisted by gravity (slope). These insights reveal potential infection hotspots, providing a glimpse in the complex interplay between parasite and host.</p>","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"21 5","pages":"20240715"},"PeriodicalIF":2.8,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12101472/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144126176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}