1
|
Sizing up swords: Correlated evolution of antlers and tusks in ruminants. J MAMM EVOL 2022. [DOI: 10.1007/s10914-022-09628-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
2
|
Chen ZY, Lin CP, Hsu Y. Stag beetle Cyclommatus mniszechi employs both mutual- and self-assessment strategies in male-male combat. Behav Processes 2022; 202:104750. [PMID: 36067873 DOI: 10.1016/j.beproc.2022.104750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 08/31/2022] [Accepted: 08/31/2022] [Indexed: 11/26/2022]
Abstract
Animals may base contest decisions on their fighting ability alone (self-assessment) or also their opponents' (mutual assessment). Many male stag beetles develop disproportionately enlarged mandibles and use them as weapons. Information on their assessment strategy is limited. To investigate their assessment strategy and whether they adopt the same strategy at different stages of contests, we used food to encourage male Cyclommatus mniszechi of different (random pairings) or similar (ML-matched pairings) mandible length (ML) to interact. For the random pairings, losers had shorter mandibles than winners and were faster to feed. Overall contest duration and the tendency to escalate to tussles associated positively with winners' ML and average ML in the random and the ML-matched pairings, respectively, consistent with self-assessment. Non-tussle phase duration associated positively with average ML in the ML-matched pairings, consistent with self-assessment. Tussle phase duration, however, positively associated with losers' ML in the random pairings and had no association with average ML in the ML-matched pairings, consistent with mutual assessment. These results show that (1) the males employ both assessment strategies, (2) winners have more control over contest intensity than losers, and (3) males with shorter mandibles are quicker to feed and also more likely to lose fights.
Collapse
Affiliation(s)
- Zhen-Yi Chen
- Department of Life Science, National Taiwan Normal University, No. 88, Section 4, Tingzhou Rd., Taipei 11677, Taiwan
| | - Chung-Ping Lin
- Department of Life Science, National Taiwan Normal University, No. 88, Section 4, Tingzhou Rd., Taipei 11677, Taiwan
| | - Yuying Hsu
- Department of Life Science, National Taiwan Normal University, No. 88, Section 4, Tingzhou Rd., Taipei 11677, Taiwan.
| |
Collapse
|
3
|
Tszydel M, Błońska D. Intra- and interspecific competition resulting from spatial coexistence among larvae of closely-related caddisflies from the genus Hydropsyche. PeerJ 2022; 10:e13576. [PMID: 35765593 PMCID: PMC9233898 DOI: 10.7717/peerj.13576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 05/22/2022] [Indexed: 01/17/2023] Open
Abstract
Caddisfly larvae commonly inhabit freshwater ecosystems, where they often create multi-species aggregations. However, while several strategies have been developed to avoid or reduce inter- and intraspecific interactions, most species choose the same time to seek a suitable place for pupation, which can increase competition. The current study assesses the competitive interactions among larvae (5th instar) of three co-existing Hydropsyche species, viz. H. contubernalis, H. pellucidula, and H. modesta, analysing their direct one-on-one interaction and various morphological features, such as size, weight, and mandibles. More than half of the interspecific conflicts ended with a draw, and 80% of intraspecific interactions with a decisive outcome. In fights between species, H. pellucidula was the most successful, and H. modesta the weakest. Our results confirm that among the larvae, competitive interactions were usually decided by body size, especially that of the head capsule. Although wider head capsule and higher weight were advantageous for ~60% of winning larvae, there were no distinct winning species. The chewing mouthpart turned out to be supportive in the fight: regardless of the species, longer and wider mandibles were significant for winning specimens, but not the distance between mandibles. Hence, acquiring a suitable place for pupation is determined by the possession of certain features enhancing the fighting potential of individual larvae, which does not exclude any species from the possibility of closing the life cycle. Future studies on interactions among caddisfly larvae could include experience in fights, volitional features and stridulation (not tested).
Collapse
|
4
|
Palaoro AV, García-Hernández S, Buzatto BA, Machado G. Function predicts the allometry of contest-related traits, but not sexual or male dimorphism in the amazonian tusked harvestman. Evol Ecol 2022. [DOI: 10.1007/s10682-022-10152-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
5
|
Batucan LS, Hsu YH, Maliszewski JW, Wang LJ, Lin CP. Novel wing display and divergent agonistic behaviors of two incipient Psolodesmus damselflies. Naturwissenschaften 2021; 108:49. [PMID: 34601627 DOI: 10.1007/s00114-021-01758-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 09/13/2021] [Accepted: 09/13/2021] [Indexed: 11/25/2022]
Abstract
Sexual selection via male competition is a strong evolutionary force that can drive rapid changes in competitive traits and subsequently lead to population divergence and speciation. Territorial males of many odonates are known to use their colorful wings as visual signals and to perform agonistic displays toward intruders. Psolodesmus mandarinus dorothea and Psolodesmus mandarinus mandarinus are two parapatrically distributed sister damselflies that share similar ecological characteristics but differ markedly in wing coloration. The wings of P. m. dorothea are mostly clear, whereas those of P. m. mandarinus have a large area of black pigmentation and a central white patch. We investigated whether territorial males of the two damselflies at breeding sites display distinct agonistic behaviors associated with their respective wing colors. Behavioral interactions between territorial and intruder males and their wing kinematics were filmed and analyzed for P. m. dorothea in Lienhuachih of central Taiwan, and P. m. mandarinus in Tianxiyuan and Fusan of northern Taiwan. We observed that the P. m. mandarinus males exhibited a novel set of perched wing displays, which was not only absent in its sister P. m. dorothea but also previously unknown in Odonata. At breeding sites, perched rival males of P. m. mandarinus with pigmented wings exhibited escalating agonistic wing-flapping and wing-hitting displays toward each other. In contrast, territorial males of P. m. dorothea with clear wings engaged only in aerial chase or face-to-face hovering when intruder males approached from the air. These results indicate that the two sister P. mandarinus damselflies diverged behaviorally in territorial contests and support the hypothesis of coadaptation on the basis of wing colors and types of wing movement in Odonata. Our findings further suggest that divergent agonistic wing displays may play a pivotal role in the speciation mechanism of P. mandarinus damselflies. The sequential analyses of behavioral characteristics and progression suggest that P. m. mandarinus damselflies likely use mutual assessment of rivals in territorial contests.
Collapse
Affiliation(s)
- Leocris S Batucan
- Department of Life Science, National Taiwan Normal University, No. 88, Section 4, Tingzhou Road, Taipei, 11677, Taiwan
- Biodiversity Program, Taiwan International Graduate Program, Academia Sinica, Taipei, 11529, Taiwan
| | - Yu-Hsun Hsu
- Department of Life Science, National Taiwan Normal University, No. 88, Section 4, Tingzhou Road, Taipei, 11677, Taiwan
- Department of Life Science, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Jak W Maliszewski
- Biodiversity Program, Taiwan International Graduate Program, Academia Sinica, Taipei, 11529, Taiwan
| | - Liang-Jong Wang
- Division of Forest Protection, Taiwan Forestry Research Institution, Taipei, 10066, Taiwan
| | - Chung-Ping Lin
- Department of Life Science, National Taiwan Normal University, No. 88, Section 4, Tingzhou Road, Taipei, 11677, Taiwan.
- Biodiversity Program, Taiwan International Graduate Program, Academia Sinica, Taipei, 11529, Taiwan.
| |
Collapse
|
6
|
Packard GC. When perception isn’t reality: allometric variation in the exaggerated mandibles of male stag beetles (Coleoptera: Lucanidae). Biol J Linn Soc Lond 2021. [DOI: 10.1093/biolinnean/blab100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
A variety of protocols have been used to study allometric variation in size of the exaggerated mandibles on male stag beetles. Many of these protocols entail logarithmic transformation of the original measurements followed by numerical analysis of the transformations by linear regression or some conceptual extension thereof. I reanalysed data from four such studies to show how these protocols can lead investigators to conclusions that are not well supported by the original observations. One of the data sets was originally reported to conform to simple loglinear allometry, with untransformed observations that presumably follow the path of a two-parameter power function; one was said to represent biphasic, loglinear allometry, with two distinctive morphs having different scaling relationships on the arithmetic scale; and two were originally described as cases of discontinuous, loglinear allometry caused by dimorphisms. My analyses, which were based on graphical analysis and nonlinear regression of untransformed observations, revealed that all the data sets form S-shaped distributions and that each of the distributions is well described by a four-parameter sigmoid function. None of the bivariate distributions reveals a discontinuity or dimorphism. Thus, the original authors unknowingly offered descriptions and interpretations for patterns of variation that do not exist in their data.
Collapse
Affiliation(s)
- Gary C Packard
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| |
Collapse
|
7
|
Benítez HA, Sukhodolskaya RA, Órdenes-Clavería R, Avtaeva TA, Kushalieva SA, Saveliev AA. Measuring the Inter and Intraspecific Sexual Shape Dimorphism and Body Shape Variation in Generalist Ground Beetles in Russia. INSECTS 2020; 11:insects11060361. [PMID: 32531974 PMCID: PMC7349662 DOI: 10.3390/insects11060361] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 05/25/2020] [Accepted: 05/29/2020] [Indexed: 11/30/2022]
Abstract
Ground beetles in multiple species vary greatly in the expression of the shape on sexual traits, resulting in a sexual shape dimorphism as a consequence of sexual selection differences. The present research focuses on the study of inter and intrasexual sexual shape dimorphism of two generalist genera of ground beetles Pterostichus and Carabus. Geometric morphometric methods were applied to five generalist species of ground beetles Carabus exaratus, C. granulatus, Pterostichus melanarius, P. niger, and P. oblongopunctatus and several multivariate analyses were applied for two different traits, abdomen and elytra. Three of the five species analyzed showed high levels of sex-based shape dimorphism. However, the most generalist species, P. melanarius and P. oblongopunctatus, did not evidence shape-based sexual dimorphism differentiation in both of the analyzed traits, as statistically confirmed based on the permutation of pairwise comparison of the Mahalanobis distances of a sex–species classifier. It is generally known that environmental stress in natural populations can affect the fitness expression, principally related to sexual fecundity, being that this pattern is more evident in non-generalist species. In our results, the contrary pattern was found, with the absence of sexual shape dimorphism for two of the three generalist species analyzed. On the other hand, the interspecies shape variation was clearly identified using principal component analysis of both of the analyzed traits. Finally, this research is the first to analyze the relationship between sexual shape dimorphism in Russian ground beetles, evidencing the lack of understanding of the mechanism underlying the sexual dimorphism, especially in species living in extreme environments.
Collapse
Affiliation(s)
- Hugo A. Benítez
- Laboratorio de Ecología y Morfometría Evolutiva, Centro de Investigación de Estudios Avanzados del Maule, Universidad Católica del Maule, Talca 3466706, Chile;
- Correspondence: ; Tel.: +56-978895630
| | - Raisa A. Sukhodolskaya
- Institute of Ecology and Mineral Resource Management Academy of Sciences of Tatarstan Republic, Tatarstan, Kazan 420000, Russia;
| | - Rodrigo Órdenes-Clavería
- Laboratorio de Ecología y Morfometría Evolutiva, Centro de Investigación de Estudios Avanzados del Maule, Universidad Católica del Maule, Talca 3466706, Chile;
| | - Tamara A. Avtaeva
- Kh. Ibragimov Complex Institute of the Russian Academy of Sciences, Grozny 364014, Russia;
| | - Shapaat A. Kushalieva
- Department of Biology and Methods of Teaching (Head), Chechen State Pedagogical University, Grozny 364014, Russia;
| | - Anatoly A. Saveliev
- Department of Ecosystem Modeling, Kazan (Volga Region) Federal University, Kazan 420000, Russia;
| |
Collapse
|