Bite force is an important performance indicator of individual fitness that is closely related to food acquisition, male competition, and mating selection. It is also affected by a variety of factors and different mechanisms. Therefore, it is relatively difficult to understand the evolutionary driving forces of changes in bite force. In this study, the driving factors affecting the bite force of wild-derived red junglefowl (Gallus gallus jabouillei) were investigated from the aspects of morphological indicators and physiological characteristics. Results showed that the bite force of wild-derived red junglefowl was directly related to sex, showing obvious sexual differences. However, there was no correlation between the plasma testosterone level and bite force. The bite force of males was significantly greater than that of females, and the body index (i.e., PC1 of five body measures, namely body mass, body length, wing length, tail length and tarsus length), the grasp index (i.e., tomial length × bill width) of males were significantly greater than those of females. Sexual selection may have played a key role in the evolution of bite force in the red junglefowl. Future studies should examine other key factors affecting changes in bite force, to verify the correlation between secondary sexual characteristics and bite force in red junglefowls.
{"title":"Sexual differences in bite force are not related to testosterone level in the wild-derived red junglefowl","authors":"Xiaodong Rao, Daiping Wang, Wei Liang","doi":"10.1093/cz/zoae016","DOIUrl":"https://doi.org/10.1093/cz/zoae016","url":null,"abstract":"Bite force is an important performance indicator of individual fitness that is closely related to food acquisition, male competition, and mating selection. It is also affected by a variety of factors and different mechanisms. Therefore, it is relatively difficult to understand the evolutionary driving forces of changes in bite force. In this study, the driving factors affecting the bite force of wild-derived red junglefowl (Gallus gallus jabouillei) were investigated from the aspects of morphological indicators and physiological characteristics. Results showed that the bite force of wild-derived red junglefowl was directly related to sex, showing obvious sexual differences. However, there was no correlation between the plasma testosterone level and bite force. The bite force of males was significantly greater than that of females, and the body index (i.e., PC1 of five body measures, namely body mass, body length, wing length, tail length and tarsus length), the grasp index (i.e., tomial length × bill width) of males were significantly greater than those of females. Sexual selection may have played a key role in the evolution of bite force in the red junglefowl. Future studies should examine other key factors affecting changes in bite force, to verify the correlation between secondary sexual characteristics and bite force in red junglefowls.","PeriodicalId":50599,"journal":{"name":"Current Zoology","volume":"17 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140587585","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}
Iveta Štolhoferová, Veronika Rudolfová, Hana Skalíková, Barbora Vobrubová, Daniel Frynta
The black rat (Rattus rattus) is a unique model for studying exploratory tactics due to its enormous colonizing potential. Considerable behavioral variability and consistent interindividual differences might help populations inhabit new environments and persist there even under intense pressure. Additionally, the affinity of the black rat for climbing might be another advantage, widening their potential niche. In this study, we describe the exploratory tactics of the black rats when introduced to a novel environment. In the first experiment, we tested 12 rats and calculated repeatability of their behaviors across 12 sessions of an enriched open field test. We concluded that climbing is a highly repeatable behavior that serves as an important source of interindividual variability. In the second experiment, we tested 24 black rats in a unique L-shaped arena. Each rat was tested twice. We found that the majority of rats distributed their activity evenly, exploring each part of the apparatus for a similar amount of time, thus maximizing their chances of finding resources. Nevertheless, these ‘even’ explorers still greatly differed in their level of activity, orderliness and affinity for climbing, generating large variability. In contrast, the minority of rats concentrated their activity only on a section of the new environment and were therefore characterized as selective explorers. Overall, we concluded that a combination of such exploratory tactics as well as a bias for even explorers enables black rats to quickly colonize new environments and persist there even under unfavorable conditions.
{"title":"How to explore a new environment: exploratory tactics of the black rat (Rattus rattus)","authors":"Iveta Štolhoferová, Veronika Rudolfová, Hana Skalíková, Barbora Vobrubová, Daniel Frynta","doi":"10.1093/cz/zoae015","DOIUrl":"https://doi.org/10.1093/cz/zoae015","url":null,"abstract":"The black rat (Rattus rattus) is a unique model for studying exploratory tactics due to its enormous colonizing potential. Considerable behavioral variability and consistent interindividual differences might help populations inhabit new environments and persist there even under intense pressure. Additionally, the affinity of the black rat for climbing might be another advantage, widening their potential niche. In this study, we describe the exploratory tactics of the black rats when introduced to a novel environment. In the first experiment, we tested 12 rats and calculated repeatability of their behaviors across 12 sessions of an enriched open field test. We concluded that climbing is a highly repeatable behavior that serves as an important source of interindividual variability. In the second experiment, we tested 24 black rats in a unique L-shaped arena. Each rat was tested twice. We found that the majority of rats distributed their activity evenly, exploring each part of the apparatus for a similar amount of time, thus maximizing their chances of finding resources. Nevertheless, these ‘even’ explorers still greatly differed in their level of activity, orderliness and affinity for climbing, generating large variability. In contrast, the minority of rats concentrated their activity only on a section of the new environment and were therefore characterized as selective explorers. Overall, we concluded that a combination of such exploratory tactics as well as a bias for even explorers enables black rats to quickly colonize new environments and persist there even under unfavorable conditions.","PeriodicalId":50599,"journal":{"name":"Current Zoology","volume":"156 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140587119","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}
The theoretical trade-off between immune and endocrine investment in mating animals has received mixed empirical support, particularly in reptiles. We investigated the relationship between male sexual characteristics, diet, and immune response to stress in an island population of tuatara (Sphenodon punctatus) across two mating seasons. Tuatara are promiscuous with a highly skewed mating system where males face significant competition for access to mates and post-copulatory competition for fertilisation success. We found that tuatara sperm viability and swim speed were negatively associated with the ratio of heterophils to lymphocytes and with male body condition. Additionally, sperm swim speed was negatively associated with spine area, mite load, and the total number of circulating white blood cells, but was positively associated with tick number, likely a function of social dynamics in this system where larger male size predicts greater spatial overlap with potential rivals and increased tick load. Because the production of sexual characteristics may be costly, we also investigated the effect of diet on sperm quality. We did not identify an association between diet and sperm viability. However, sperm swim speed was negatively associated with carbon-13 and positively associated with nitrogen-15. We suspect that these results reflect the influence of seabird-based nutrients in this island ecosystem, particularly poly-unsaturated fatty acids, and antioxidant damage on this tuatara sperm. In total, these results provide evidence of a trade-off between pre- and post-copulatory sexual characteristics and the immune and endocrine systems in male tuatara.
{"title":"Immune stress and diet influence reproductive fitness in male tuatara (Sphenodon punctatus)","authors":"Sarah K Lamar, Diane K Ormsby, Nicola J Nelson","doi":"10.1093/cz/zoae012","DOIUrl":"https://doi.org/10.1093/cz/zoae012","url":null,"abstract":"The theoretical trade-off between immune and endocrine investment in mating animals has received mixed empirical support, particularly in reptiles. We investigated the relationship between male sexual characteristics, diet, and immune response to stress in an island population of tuatara (Sphenodon punctatus) across two mating seasons. Tuatara are promiscuous with a highly skewed mating system where males face significant competition for access to mates and post-copulatory competition for fertilisation success. We found that tuatara sperm viability and swim speed were negatively associated with the ratio of heterophils to lymphocytes and with male body condition. Additionally, sperm swim speed was negatively associated with spine area, mite load, and the total number of circulating white blood cells, but was positively associated with tick number, likely a function of social dynamics in this system where larger male size predicts greater spatial overlap with potential rivals and increased tick load. Because the production of sexual characteristics may be costly, we also investigated the effect of diet on sperm quality. We did not identify an association between diet and sperm viability. However, sperm swim speed was negatively associated with carbon-13 and positively associated with nitrogen-15. We suspect that these results reflect the influence of seabird-based nutrients in this island ecosystem, particularly poly-unsaturated fatty acids, and antioxidant damage on this tuatara sperm. In total, these results provide evidence of a trade-off between pre- and post-copulatory sexual characteristics and the immune and endocrine systems in male tuatara.","PeriodicalId":50599,"journal":{"name":"Current Zoology","volume":"23 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140587288","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}
Ivan Norscia, Martin Hecker, Marta Caselli, Edoardo Collarini, Beatriz Gallego Aldama, Santiago Borragán Santos, Giada Cordoni
In social groups, competition for individual advantage is balanced with cooperation, for the collective benefit. Selection against aggression has favoured cooperation and non-aggressive competitive strategies. Because social play is a behavioural system that fluctuates between cooperation and competition, selection against aggression might have especially influenced this behaviour. African savannah elephants (Loxodonta africana) are a low aggressive species, therefore suitable to investigate this aspect. We collected all occurrences observational audio-video data on social play, aggression/threats, and affiliation on an African elephant colony housed in a 25-ha open space at Parque de la Naturaleza de Cabarceno (Cantabria, Spain) and composed of four family groups (3 immature males, 3 immature females, and 7 adult females) and two adult males. Anticipating the influence of reduced aggression, we found that social play decreased with age, persisting in adults, and that it was highest in males. Social play was associated with affiliation (informing cooperation). Indeed, individuals that were central in the social play network were also central in the affiliation network. For immature subjects, we found a correlation between social play and affiliation sociomatrices. However, such correlation was absent in adults and social play mostly occurred between families. Despite the limitations related to dealing with a small captive group, this study largely supports the idea that the features of social play in African savannah elephants may be related to low aggression. This investigation hints toward a non purely cooperative use of play, possibly as a non-aggressive interaction that accommodates different levels of cooperation and competition.
在社会群体中，为了个人利益的竞争与为了集体利益的合作是平衡的。针对攻击性的选择有利于合作和非攻击性的竞争策略。由于社交游戏是一种在合作与竞争之间波动的行为系统，因此针对攻击性的选择可能会对这种行为产生特别的影响。非洲草原象（Loxodonta africana）是攻击性较低的物种，因此适合研究这方面的问题。我们收集了一个非洲象群的所有社交游戏、攻击/威胁和隶属关系的音频视频观察数据，该象群位于西班牙坎塔布里亚卡巴塞诺自然公园（Parque de la Naturaleza de Cabarceno）的一个25公顷的空地上，由4个家庭群（3个未成年雄象、3个未成年雌象和7个成年雌象）和2个成年雄象组成。我们发现，随着年龄的增长，社交游戏会减少，但成年后仍会持续，而且雄性的社交游戏最多。社交游戏与隶属关系（合作信息）有关。事实上，在社交游戏网络中处于中心位置的个体在附属关系网络中也处于中心位置。对于未成年被试，我们发现社交游戏和从属关系社会矩阵之间存在相关性。然而，这种相关性在成年人中并不存在，而且社交游戏大多发生在家庭之间。尽管这项研究受到圈养小象群体的限制，但它在很大程度上支持了非洲草原象的社交游戏特征可能与低攻击性有关的观点。这项调查暗示了游戏的非纯粹合作性使用，可能是一种非攻击性的互动，可容纳不同程度的合作和竞争。
{"title":"Social Play In African Savannah Elephants May Inform Selection Against Aggression","authors":"Ivan Norscia, Martin Hecker, Marta Caselli, Edoardo Collarini, Beatriz Gallego Aldama, Santiago Borragán Santos, Giada Cordoni","doi":"10.1093/cz/zoae009","DOIUrl":"https://doi.org/10.1093/cz/zoae009","url":null,"abstract":"In social groups, competition for individual advantage is balanced with cooperation, for the collective benefit. Selection against aggression has favoured cooperation and non-aggressive competitive strategies. Because social play is a behavioural system that fluctuates between cooperation and competition, selection against aggression might have especially influenced this behaviour. African savannah elephants (Loxodonta africana) are a low aggressive species, therefore suitable to investigate this aspect. We collected all occurrences observational audio-video data on social play, aggression/threats, and affiliation on an African elephant colony housed in a 25-ha open space at Parque de la Naturaleza de Cabarceno (Cantabria, Spain) and composed of four family groups (3 immature males, 3 immature females, and 7 adult females) and two adult males. Anticipating the influence of reduced aggression, we found that social play decreased with age, persisting in adults, and that it was highest in males. Social play was associated with affiliation (informing cooperation). Indeed, individuals that were central in the social play network were also central in the affiliation network. For immature subjects, we found a correlation between social play and affiliation sociomatrices. However, such correlation was absent in adults and social play mostly occurred between families. Despite the limitations related to dealing with a small captive group, this study largely supports the idea that the features of social play in African savannah elephants may be related to low aggression. This investigation hints toward a non purely cooperative use of play, possibly as a non-aggressive interaction that accommodates different levels of cooperation and competition.","PeriodicalId":50599,"journal":{"name":"Current Zoology","volume":"115 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140107687","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}
Ongoing wind energy developments play a key role in mitigating the global effects of climate change and the energy crisis; however, they have complex ecological consequences for many flying animals. The Yellow Sea coast is considered as an ecological bottleneck for migratory waterbirds along the East Asian–Australasian flyway (EAAF), and is also an important wind farm base in China. However, the effects of large-scale onshore wind farms along the EAAF on multidimensional waterbird diversity, and how to mitigate these effects, remain unclear. Here we examined how wind farms and their surrounding landscapes affected multidimensional waterbird diversity along the Yellow Sea coast. Taxonomic, functional, and phylogenetic diversity of the waterbird assemblages, and mean pairwise distances and nearest taxon distances with null models were quantified in relation to four different wind turbine densities. We also measured six landscape variables. Multi-dimensional waterbird diversity (taxonomic, functional, and phylogenetic diversity) significantly decreased with increasing wind turbine density. Functional and phylogenetic structures tended to be clustered in waterbird communities, and environmental filtering drove waterbird community assemblages. Furthermore, waterbird diversity was regulated by a combination of wind turbine density and landscape variables, with edge density of aquaculture ponds, in addition to wind turbine density, having the greatest independent contribution to waterbird diversity. These results suggest that attempts to mitigate the impact of wind farms on waterbird diversity could involve the landscape transformation of wind farm regions, e.g., by including high-edge-density aquaculture ponds (i.e. industrial ponds) around wind farms, instead of traditional low-edge-density aquaculture ponds.
{"title":"Prioritizing landscapes for mitigating the impacts of onshore wind farms on multidimensional waterbird diversity in the Yellow Sea","authors":"Shanshan Zhao, Huan Xu, Tianhou Wang, Hepeng Li, Xiuzhen Li, Ningning Liu, Xiao Song, Feng Guan, Xuechu Chen, Aichun Xu, Ben Li","doi":"10.1093/cz/zoae008","DOIUrl":"https://doi.org/10.1093/cz/zoae008","url":null,"abstract":"Ongoing wind energy developments play a key role in mitigating the global effects of climate change and the energy crisis; however, they have complex ecological consequences for many flying animals. The Yellow Sea coast is considered as an ecological bottleneck for migratory waterbirds along the East Asian–Australasian flyway (EAAF), and is also an important wind farm base in China. However, the effects of large-scale onshore wind farms along the EAAF on multidimensional waterbird diversity, and how to mitigate these effects, remain unclear. Here we examined how wind farms and their surrounding landscapes affected multidimensional waterbird diversity along the Yellow Sea coast. Taxonomic, functional, and phylogenetic diversity of the waterbird assemblages, and mean pairwise distances and nearest taxon distances with null models were quantified in relation to four different wind turbine densities. We also measured six landscape variables. Multi-dimensional waterbird diversity (taxonomic, functional, and phylogenetic diversity) significantly decreased with increasing wind turbine density. Functional and phylogenetic structures tended to be clustered in waterbird communities, and environmental filtering drove waterbird community assemblages. Furthermore, waterbird diversity was regulated by a combination of wind turbine density and landscape variables, with edge density of aquaculture ponds, in addition to wind turbine density, having the greatest independent contribution to waterbird diversity. These results suggest that attempts to mitigate the impact of wind farms on waterbird diversity could involve the landscape transformation of wind farm regions, e.g., by including high-edge-density aquaculture ponds (i.e. industrial ponds) around wind farms, instead of traditional low-edge-density aquaculture ponds.","PeriodicalId":50599,"journal":{"name":"Current Zoology","volume":"95 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140097640","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}
Deming Yang, Kevin T Uno, Thure E Cerling, Ogeto Mwebi, Louise N Leakey, Frederick E Grine, Antoine Souron
How animals respond to seasonal resource availability has profound implications for their dietary flexibility and realized ecological niches. We sought to understand seasonal dietary niche partitioning in extant African suids using intra-tooth stable isotope analysis of enamel. We collected enamel samples from canines of red river hogs/bushpigs (Potamochoerus spp.) and third molars of warthogs (Phacochoerus spp.) in three different regions of central and eastern Africa. We analyzed multiple samples from each tooth and used variations in stable carbon and oxygen isotope ratios (δ13C and δ18O) and covariances between them to infer seasonal dietary changes. We found that most Phacochoerus display C4-dominated diets, while most Potamochoerus display C3-dominated diets. Phacochoerus and Potamochoerus that co-occur in the same region display no overlap in intra-tooth δ13C, which suggests dietary niche partitioning. They also show diverging δ13C values as the dry seasons progress and converging δ13C values during the peak of the rainy seasons, which suggests a greater dietary niche separation during the dry seasons when resources are scarce than during the rainy season. We found statistically significant cross-correlations between intra-tooth δ13C and δ18O in most specimens. We also observed a temporal lag between δ13C and δ18O in some specimens. This study demonstrates that intra-tooth stable isotope analysis is a promising approach to investigate seasonal dietary niche variation. However, large inter-individual variations in δ18O at certain localities can be challenging to interpret. Future studies that expand the intra-tooth stable isotope surveys or include controlled feeding experiments will improve its application in ecological studies.
{"title":"Intra-tooth stable isotope analysis reveals seasonal dietary variability and niche partitioning among bushpigs/red river hogs and warthogs","authors":"Deming Yang, Kevin T Uno, Thure E Cerling, Ogeto Mwebi, Louise N Leakey, Frederick E Grine, Antoine Souron","doi":"10.1093/cz/zoae007","DOIUrl":"https://doi.org/10.1093/cz/zoae007","url":null,"abstract":"How animals respond to seasonal resource availability has profound implications for their dietary flexibility and realized ecological niches. We sought to understand seasonal dietary niche partitioning in extant African suids using intra-tooth stable isotope analysis of enamel. We collected enamel samples from canines of red river hogs/bushpigs (Potamochoerus spp.) and third molars of warthogs (Phacochoerus spp.) in three different regions of central and eastern Africa. We analyzed multiple samples from each tooth and used variations in stable carbon and oxygen isotope ratios (δ13C and δ18O) and covariances between them to infer seasonal dietary changes. We found that most Phacochoerus display C4-dominated diets, while most Potamochoerus display C3-dominated diets. Phacochoerus and Potamochoerus that co-occur in the same region display no overlap in intra-tooth δ13C, which suggests dietary niche partitioning. They also show diverging δ13C values as the dry seasons progress and converging δ13C values during the peak of the rainy seasons, which suggests a greater dietary niche separation during the dry seasons when resources are scarce than during the rainy season. We found statistically significant cross-correlations between intra-tooth δ13C and δ18O in most specimens. We also observed a temporal lag between δ13C and δ18O in some specimens. This study demonstrates that intra-tooth stable isotope analysis is a promising approach to investigate seasonal dietary niche variation. However, large inter-individual variations in δ18O at certain localities can be challenging to interpret. Future studies that expand the intra-tooth stable isotope surveys or include controlled feeding experiments will improve its application in ecological studies.","PeriodicalId":50599,"journal":{"name":"Current Zoology","volume":"3 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140097635","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}
Chengxiu Zhan, Bicheng Li, Chuanwu Chen, Yanping Wang
Nestedness is an important part of the theoretical framework of island biogeography and community ecology. However, most previous studies focused on taxonomic dimension and overlooked functional and phylogenetic nestedness. Here, we simultaneously investigated taxonomic, functional, and phylogenetic nestedness of terrestrial mammals on 39 land-bridge islands in the Zhoushan Archipelago, China. As mammals’ response to the environment may depend on their body size, we performed analyses for three mammal assemblages separately: overall species, large and medium species and small species. The taxonomic nestedness was quantified by organizing the species incidence matrix, while the functional and phylogenetic nestedness were estimated by combining the similarity of their ecological traits and phylogeny. Island characteristics (island area, three isolation indices, land use intensity and habitat diversity) and species traits (body size, litter size, habitat specificity, geographic range size and minimum area requirement) were used as predictors of nestedness. Overall and small species were significantly nested in three facets of nestedness, and results supported the selective extinction, selective colonization and habitat nestedness hypotheses. Large and medium species was functionally and phylogenetically nested when matrices were ordered by increasing distance to mainland, supporting the selective colonization hypothesis. Overall, differences in nestedness and its underlying mechanisms were detected not only in three facets of nestedness but also in the three mammal assemblages. Therefore, frameworks that incorporate taxonomic, phylogenetic, and functional nestedness can contribute to a more comprehensive understanding of nestedness processes. Additionally, it also improves our ability to understand divergent responses of mammal assemblages to the insular environment.
{"title":"Taxonomic, phylogenetic and functional nestedness of mammal assemblages in the Zhoushan Archipelago, China","authors":"Chengxiu Zhan, Bicheng Li, Chuanwu Chen, Yanping Wang","doi":"10.1093/cz/zoae006","DOIUrl":"https://doi.org/10.1093/cz/zoae006","url":null,"abstract":"Nestedness is an important part of the theoretical framework of island biogeography and community ecology. However, most previous studies focused on taxonomic dimension and overlooked functional and phylogenetic nestedness. Here, we simultaneously investigated taxonomic, functional, and phylogenetic nestedness of terrestrial mammals on 39 land-bridge islands in the Zhoushan Archipelago, China. As mammals’ response to the environment may depend on their body size, we performed analyses for three mammal assemblages separately: overall species, large and medium species and small species. The taxonomic nestedness was quantified by organizing the species incidence matrix, while the functional and phylogenetic nestedness were estimated by combining the similarity of their ecological traits and phylogeny. Island characteristics (island area, three isolation indices, land use intensity and habitat diversity) and species traits (body size, litter size, habitat specificity, geographic range size and minimum area requirement) were used as predictors of nestedness. Overall and small species were significantly nested in three facets of nestedness, and results supported the selective extinction, selective colonization and habitat nestedness hypotheses. Large and medium species was functionally and phylogenetically nested when matrices were ordered by increasing distance to mainland, supporting the selective colonization hypothesis. Overall, differences in nestedness and its underlying mechanisms were detected not only in three facets of nestedness but also in the three mammal assemblages. Therefore, frameworks that incorporate taxonomic, phylogenetic, and functional nestedness can contribute to a more comprehensive understanding of nestedness processes. Additionally, it also improves our ability to understand divergent responses of mammal assemblages to the insular environment.","PeriodicalId":50599,"journal":{"name":"Current Zoology","volume":"4 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140045086","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}
Environmental conditions change constantly either by anthropogenic perturbation or naturally across space and time. Often, a change in behaviour is the first response to changing conditions. Behavioural flexibility can potentially improve an organism’s chances to survive and reproduce. Currently, we lack an understanding on the time-scale such behavioural adjustments need, how they actually affect reproduction and survival and whether behavioural adjustments are sufficient in keeping up with changing conditions. We used house mice (Mus musculus) to test whether personality and life-history traits can adjust to an experimentally induced food-switch flexibly in adulthood or by intergenerational plasticity, i.e., adjustments only becoming visible in the offspring generation. Mice lived in six experimental populations of semi-natural environments either on high or standard quality food for four generations. We showed previously that high-quality food induced better condition and a less risk-prone personality. Here, we tested whether the speed and/ or magnitude of adjustment shows condition-dependency and whether adjustments incur fitness effects. Life-history but not personality traits reacted flexibly to a food-switch, primarily by a direct reduction of reproduction and slowed-down growth. Offspring whose parents received a food-switch developed a more active stress-coping personality and gained weight at a slower rate compared to their respective controls. Furthermore, the modulation of most traits was condition-dependent, with animals previously fed with high-quality food showing stronger responses. Our study highlights that life-history and personality traits adjust at different speed towards environmental change, thus, highlighting the importance of the environment and the mode of response for evolutionary models.
{"title":"Is the speed of adjusting to environmental change condition dependent? An experiment with house mice (Mus musculus)","authors":"Karem Lopez-Hervas, Neelam Porwal, Mathilde Delacoux, Alexandros Vezyrakis, Anja Guenther","doi":"10.1093/cz/zoae005","DOIUrl":"https://doi.org/10.1093/cz/zoae005","url":null,"abstract":"Environmental conditions change constantly either by anthropogenic perturbation or naturally across space and time. Often, a change in behaviour is the first response to changing conditions. Behavioural flexibility can potentially improve an organism’s chances to survive and reproduce. Currently, we lack an understanding on the time-scale such behavioural adjustments need, how they actually affect reproduction and survival and whether behavioural adjustments are sufficient in keeping up with changing conditions. We used house mice (Mus musculus) to test whether personality and life-history traits can adjust to an experimentally induced food-switch flexibly in adulthood or by intergenerational plasticity, i.e., adjustments only becoming visible in the offspring generation. Mice lived in six experimental populations of semi-natural environments either on high or standard quality food for four generations. We showed previously that high-quality food induced better condition and a less risk-prone personality. Here, we tested whether the speed and/ or magnitude of adjustment shows condition-dependency and whether adjustments incur fitness effects. Life-history but not personality traits reacted flexibly to a food-switch, primarily by a direct reduction of reproduction and slowed-down growth. Offspring whose parents received a food-switch developed a more active stress-coping personality and gained weight at a slower rate compared to their respective controls. Furthermore, the modulation of most traits was condition-dependent, with animals previously fed with high-quality food showing stronger responses. Our study highlights that life-history and personality traits adjust at different speed towards environmental change, thus, highlighting the importance of the environment and the mode of response for evolutionary models.","PeriodicalId":50599,"journal":{"name":"Current Zoology","volume":"137 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140074311","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}
Inbreeding and loss of genetic diversity increase the extinction risk of small isolated populations. Genetic rescue by augmenting gene flow is a powerful means for the restoration of lost genetic variation. In this study, we used multigenerational pedigrees and neutral genetic markers to assess the consequences of outbreeding management in the Chinese and Vietnamese populations of the endangered crocodile lizard (Shinisaurus crocodilurus). Compared with the purebred Chinese population, the outbreeding population exhibited greater molecular genetic variation and a threefold larger population size. Moreover, the first-generation hybrids had a longer lifespan than purebreds, suggesting that outbreeding depression did not occur, but the long-term fitness effect of outbreeding needs to be further evaluated. Our study provides valuable insights into the potential for genetic rescue in the endangered crocodile lizard, emphasizing the importance of an evidence-based genetic management approach to address the risks of inbreeding and outbreeding depression in threatened populations.
{"title":"Outbreeding management offers the promise of genetic rescue for an endangered lizard","authors":"Guannan Wen, Hongxin Xie, Shuyi Luo, Chunsheng Yang, Xianwu Tang, Yibo Hu, Weiguo Du","doi":"10.1093/cz/zoae003","DOIUrl":"https://doi.org/10.1093/cz/zoae003","url":null,"abstract":"Inbreeding and loss of genetic diversity increase the extinction risk of small isolated populations. Genetic rescue by augmenting gene flow is a powerful means for the restoration of lost genetic variation. In this study, we used multigenerational pedigrees and neutral genetic markers to assess the consequences of outbreeding management in the Chinese and Vietnamese populations of the endangered crocodile lizard (Shinisaurus crocodilurus). Compared with the purebred Chinese population, the outbreeding population exhibited greater molecular genetic variation and a threefold larger population size. Moreover, the first-generation hybrids had a longer lifespan than purebreds, suggesting that outbreeding depression did not occur, but the long-term fitness effect of outbreeding needs to be further evaluated. Our study provides valuable insights into the potential for genetic rescue in the endangered crocodile lizard, emphasizing the importance of an evidence-based genetic management approach to address the risks of inbreeding and outbreeding depression in threatened populations.","PeriodicalId":50599,"journal":{"name":"Current Zoology","volume":"46 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140008011","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}
The present review provides a compilation of the published data on the ecology and social behaviour of tamarisk gerbils. Both field studies and direct observations under semi-natural conditions provide evidence that the tamarisk gerbil is a nocturnal herbivorous rodent that lives in highly seasonal habitats and displays seasonal fluctuations in reproduction and spatial organization. A typical feature of the tamarisk gerbils' spatial organization is higher mobility of males during the breeding season (as compared to the non-breeding period) and formation of temporary aggregations of males competing for access to receptive females; the composition of these aggregations was variable and depended on the reproductive condition of the females. Females tend to occupy exclusive home ranges irrespective of their reproductive condition. The mating system of the species can be defined as scramble competition polygyny with some features of polygynandry and promiscuity. The tamarisk gerbil has distinct features of a solitary species and its social structure is primarily based on aggressive interactions or mutual avoidance of conspecifics resulting in a dominance hierarchy among males and site-dependent dominance among females during the breeding season. By the end of the breeding season, males become less mobile and occupy nearly exclusive home ranges, consistent with solitary living. The main features of the spatial and social organization of this species, which distinguish it from other solitary rodents, are the higher mobility of males and the formation of temporary multi-male–multi-female aggregations during the breeding season. Overall, the data presented expand our understanding of socio-ecology of gerbils.
{"title":"Ecology and social behavior of the tamarisk gerbil Meriones tamariscinus: Insights from long-term research in the wild and seminatural environments","authors":"Vladimir S Gromov","doi":"10.1093/cz/zoae004","DOIUrl":"https://doi.org/10.1093/cz/zoae004","url":null,"abstract":"The present review provides a compilation of the published data on the ecology and social behaviour of tamarisk gerbils. Both field studies and direct observations under semi-natural conditions provide evidence that the tamarisk gerbil is a nocturnal herbivorous rodent that lives in highly seasonal habitats and displays seasonal fluctuations in reproduction and spatial organization. A typical feature of the tamarisk gerbils' spatial organization is higher mobility of males during the breeding season (as compared to the non-breeding period) and formation of temporary aggregations of males competing for access to receptive females; the composition of these aggregations was variable and depended on the reproductive condition of the females. Females tend to occupy exclusive home ranges irrespective of their reproductive condition. The mating system of the species can be defined as scramble competition polygyny with some features of polygynandry and promiscuity. The tamarisk gerbil has distinct features of a solitary species and its social structure is primarily based on aggressive interactions or mutual avoidance of conspecifics resulting in a dominance hierarchy among males and site-dependent dominance among females during the breeding season. By the end of the breeding season, males become less mobile and occupy nearly exclusive home ranges, consistent with solitary living. The main features of the spatial and social organization of this species, which distinguish it from other solitary rodents, are the higher mobility of males and the formation of temporary multi-male–multi-female aggregations during the breeding season. Overall, the data presented expand our understanding of socio-ecology of gerbils.","PeriodicalId":50599,"journal":{"name":"Current Zoology","volume":"72 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140007892","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}
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