Mating Behavior Research Articles

Genetic Screening Reveals Cone Cell-Specific Factors as Common Genetic Targets Modulating Rival-Induced Prolonged Mating in male Drosophila melanogaster.

Male-male social interactions exert a substantial impact on the transcriptional regulation of genes associated with aggression and mating behavior in male Drosophila melanogaster. Throughout our comprehensive genetic screening of aggression-related genes, we identified that the majority of mutants for these genes are associated with rival-induced and visually-oriented mating behavior, longer-mating-duration (LMD). The majority of mutants with upregulated genes in single-housed males significantly altered LMD behavior but not copulation latency, suggesting a primary regulation of mating duration. Single-cell RNA sequencing revealed that LMD-related genes are predominantly co-expressed with male-specific genes like dsx and Cyp6a20 in specific cell populations, especially in cone cells. Functional validation confirmed the roles of these genes in mediating LMD. Expression of LMD genes like Cyp6a20, Cyp4d21, and CrzR was enriched in cone cells, with disruptions in cone cell-specific expression of CrzR and Cyp4d21 leading to disrupted LMD. We also identified a novel gene, CG10026/Macewindu, that reversed LMD when overexpressed in cone cells. These findings underscore the critical role of cone cells as a pivotal site for the expression of genes involved in the regulation of LMD behavior. This study provides valuable insights into the intricate mechanisms underlying complex sexual behaviors in Drosophila.

Deafness due to loss of a TRPV channel eliminates mating behavior in Aedes aegypti males

Attraction and mating between male and female animals depend on effective communication between conspecifics. However, in mosquitoes, we have only a rudimentary understanding of the sensory cues and receptors critical for the communication that is essential for reproductive behavior. While it is known that male Aedes aegypti use sound to help them identify females, it is not unclear whether sound detection is absolutely required since other cues such as vision may also participate in mating behavior. To determine the effect of eliminating hearing on mating success, we knocked out the Ae. aegypti TRPVa channel, which is a protein expressed in chordotonal neurons in the Johnston's organ (JO) that respond to sound-induced movements in the antenna. Loss of trpVa eradicated sound-induced responses from the JO, thereby abolishing hearing. Strikingly, mutation of trpVa eliminated mating behavior in males. In contrast, trpVa-null females mated, although this behavior was slightly delayed relative to wild-type females. Males and females produce sounds as they beat their wings at distinct frequencies during flight. Sound mimicking the female wingbeat induced flight, attraction, and copulatory-like behavior in wild-type males without females present, but not in trpVa-null males. Males are known to modulate their wingbeat frequencies before mating in the air, which is a phenomenon referred to as rapid frequency modulation (RFM). We found that RFM was absent in mosquitoes lacking TRPVa. We conclude that the requirement for trpVa and hearing for male reproductive behavior in Aedes is absolute, as mating in the deaf males is eliminated.

Adaptive Significance of Long Mating With Repeated Intromissions in Zygogramma bicolorata

ABSTRACTLong matings are abundant in insects despite the range of the costs involved. The causes and consequences of the evolution of long mating remain an interesting problem for behavioural ecologists. We studied extraordinarily long mating that involves repeated intromissions interspersed with latent periods in the Parthenium beetle (Zygogramma bicolorata). We conducted a series of interrupted mating assays to examine the fitness consequences of different components of this curious mating behaviour. We tested multiple adaptive hypotheses concerning male fertility and competitive ability. We found that sperm transfer and fertility did not exhibit a linear increase with the number of intromissions. There was also no evidence of nutrient transfer by the males. Interestingly, our results showed that both sexes suffered a significant cost of long mating. Further, female remating behaviour was found to be modulated by the length of the previous mating. Additionally, males were observed performing a curious leg rubbing behaviour during the inter‐intromission latent period, putatively serving as a copulatory courtship function that reduced female resistance to the continuance of mating. Therefore, we show that while the long mating may still serve a mate‐guarding role, there are additional fitness effects of such behaviour that need careful consideration. Our study provides insights into the adaptive significance of long mating and its fitness consequences.

Novo plant-based mosquito repellent shows promise for exclusion of Aedes mosquitoes from "window" entry.

Mosquitoes threaten over half of the world's population through vectored diseases such as malaria, zika, yellow fever, dengue, and chikungunya. Mosquitoes have a highly developed olfactory system attuned to chemotaxis relating to host-seeking, mating, and oviposition behavior. In this study, we aimed to determine the spatial efficacy of 2 plant-based repellent blends (Blend3 and Blend4that had previously been found to successfully repel Aedes, Anopheles and Culex mosquitoes in wind tunnel assays)in excluding Aedes aegypti from the window entry. A new cage system was developed for parallel "no-choice" and "choice" olfactometric assays. In the no-choice trial, Blends 3 and 4, as well as commercial products (N, N-diethyl-3-methylbenzamide, p-menthane-3,8-diol [PMD], 3-(N-n-butyl-N-acetyl)-amino-propionic acid ethyl ester, and 2-(2-hydroxyethyl)-1-methylpropylstyrene 1-piperidine carboxylate), were adsorbed into filter papers of different sizes and placed in a window created between 2 attached bug dorms. Then, the number of mosquitoes entering the window was counted through a 6-min period. In choice olfactometric assays, Blends 3, 4, and PMD were adsorbed into filter paper and the number of mosquitoes moving away from Blend 3 and PMD were compared. No-choice assays showed that Blend3 (P < 0.001) and Blend4 (P = 0.0012) were more repellent than the best commercial product PMD. Additionally, while Blend 4 was significantly more repellent than Blend 3 (P = 0.012) in the choice assay, overall, these 2 blends show promise as new repellents for the spatial exclusion of Aedes aegypti from window entry alone or as part of a "push-pull'' strategy.

Infection by a fungal pathogen and mating behavior in Pacific treefrogs: a test of the Hamilton-Zuk hypothesis

Infection by a fungal pathogen and mating behavior in Pacific treefrogs: a test of the Hamilton-Zuk hypothesis

Don't touch me! Mating not always preceded by courtship behavior in predatory coccinellids.

Knowledge of the ecology and behavior of biological control agents is essential for their effective use in biocontrol and Integrated Pest Management (IPM)programs. There is a lack of information regarding the courtship and mating traits that are crucial for successful mating in biocontrol population of coccinellids. To expand our current understanding in this area, 2 coccinellid species commonly used for the biocontrol of soft-bodied insects, Cryptolaemus montrouzieri (Mulsant) and Propylea quatuordecimpunctata (Linnaeus) (Coleoptera: Coccinellidae), were studied. A quantitative analysis was performed to compare their courtship and mating displays. Key behavioral traits of the precopulatory, copulatory, and postcopulatory phases were investigated. The courtship and mating sequences of C. montrouzieri and P. quatuordecimpunctata were similar to each other. During the mating phase, the key displays were the opening of the elytrae and wings followed by body shaking in C. montrouzieri and leg tapping followed by body shaking in P. quatuordecimpunctata. The mating success of both species was not correlated with any courtship display, such as antennal tapping. Only in C. montrouzieri mounting attempt showed a higher frequency from the backside without affecting male mating success. This research adds baseline knowledge about the courtship and mating behavior of the biocontrol population of coccinellids, contributing to the identification of potentiallyuseful benchmarks (e.g., body shaking, leg tapping) for monitoring prolonged mass-rearing processes, thusreducing mating failures.

Females drive postmating reproductive trait evolution across Drosophila species, but not via remating rate.

While traits that contribute to premating sexual interactions are known to be wildly diverse, much less is known about the diversity of postmating (especially female) reproductive traits and the mechanisms shaping this diversity. To assess the rate, pattern, and potential drivers of postmating reproductive trait evolution, we analyzed male and female traits across up to 30 Drosophila species within a phylogenetic comparative framework. In addition to postmating reproductive morphology (e.g., sperm length, reproductive tract length and mass), we also quantified mating behaviors including female remating rate-a common proxy for the strength of postmating sexual selection. We found evidence for strong coevolution between male and female postmating traits (specifically sperm length and sperm storage organ size). However, remating rate was not associated with the rate of evolution or exaggeration of either male or female postmating reproductive morphology, once phylogenetic relatedness was accounted for. We infer that female-mediated and intersexual selection predominantly drive the evolution of our postmating morphological traits, including via divergent male and female interests in controlling paternity. In comparison, remating rate has a complex and likely secondary role in shaping this evolution, in part because this trait can be both a driver and a product of postmating selection.

Mating behaviour and cholesterol nutritional strategies promoted ovarian development of female swimming crab (Portunus trituberculatus).

Female crabs enter a stage of rapid ovarian development after mating, and cholesterol is a substrate for steroid hormone synthesis. Therefore, in this experiment, an 8-week feeding trial was conducted to investigate the effects of mating treatments (mated crab and unmated crab) and three dietary cholesterol levels (0·09 %, 0·79 % and 1·40 %) on ovarian development, cholesterol metabolism and steroid hormones metabolism of adult female swimming crab (Portunus trituberculatus). The results indicated that crabs fed the diet with 0·79 % cholesterol significantly increased gonadosomatic index (GSI) and vitellogenin (VTG) content than other treatments in the same mating status. Moreover, mated crabs had markedly increased GSI and VTG content in the ovary and hepatopancreas than unmated crabs. The histological observation found that exogenous vitellogenic oocytes appeared in the mated crabs, while previtellogenic oocytes and endogenous vitellogenic oocytes were the primary oocytes in unmated crabs. The transmission electron microscopy analysis showed that when fed diet with 0·79 % cholesterol, the unmated crabs contained more rough endoplasmic reticulum and mated crabs had higher yolk content than other treatments. Furthermore, mating treatment and dietary 0·79 % cholesterol level both promoted cholesterol deposition by up-regulation of the mRNA and protein expression levels of class B scavenger receptors 1 (Srb1), while stimulating the secretion of steroid hormones by up-regulation of the mRNA and protein expression of steroidogenic acute regulatory protein (Star). Overall, the present results indicated that mating behaviour plays a leading role in promoting ovarian development, and dietary 0·79 % cholesterol level can further promote ovarian development after mating.

Abundance, ecology and dispersal of wood bison (Bison bison athabascae Rhoads) in Yakutia

In 2006, 2011, 2013, and 2020, four groups of young wood bison, each made up of 30 individuals from Canada, were introduced to Yakutia. The bison began to reproduce at ages 2 to 3 in 2008. Their mating behavior was first noted in 2007 when they were 2 to 3 years old, and calving took place in the spring of 2008 when they were 3 to 4 years old. Between 2008 and 2023, 16 generations of calves were born from both Canadian and Yakutia-born bison. The percentage of females that gave birth varied each year, ranging from 46.2% to 92.3%, with an average of 69.3 ± 5.4%. In 2017 and 2018, some bison were released in the middle section of the Sinyaya River. By 2023, the total population of bison in the nurseries “Ust-Buotama,” “Tympynai,” and in free-ranging groups reached 348 individuals. We discuss the characteristics of pastures, plant nutrition, feeding, reproduction, reintroduction to the wild, and the distribution of bison in Yakutia and surrounding areas. Bison have adapted well to the region’s climate, which features long winters, short summers, and extremely low winter temperatures. Central Yakutia offers a broad ecological niche for bison, with shallow valley lands that have meadow and shrub vegetation. This environment supports the potential for successfully restoring the historical habitat of the Bison genus in Yakutia and nearby regions. To avoid inbreeding and preserve genetic diversity, it is crucial to regularly release animals into the wild and occasionally introduce new individuals from various parks in Canada.

Kinematics of elongate harvestmen chelicerae: Comparative range of motion analyses in extant Ischyropsalis (Dyspnoi, Opiliones)

Chelicerae, the mouthparts of chelicerates, are essential for food processing. Particularly within harvestmen (Opiliones), some species have greatly elongated their tripartite chelicerae and utilize them for mating behavior, defense, and primarily for predation. We investigated two European species, Ischyropsalis muellneri and Ischyropsalis hellwigii, which occupy different niches (caves, forests), exhibit different feeding ecologies (opportunist, specialist), and first and foremost possess different chelicerae morphologies (long and thin, short and robust). We scanned the specimens using state-of-the-art micro-CT, generated surface reconstructions, and equipped one chelicera of each specimen with artificial joints to explore their Range of Motion in a 3D kinematic approach. For a size-corrected comparison of the two species, we analyzed the Range of Motion in addition to three different settings (original body size, body scaled to 5 mm, chelicerae scaled to 5 mm). Ischyropsalis muellneri reached a higher maximum excursion angle (= single Range of Motion) in all three joints, also exhibiting a greater total Range of Motion in the original body length setting, as well as the scaled body length setting. Only in the third setting, the total Range of Motion of Ischyropsalis hellwigii was slightly higher, although Ischyropsalis muellneri still extended further ventrally. Our results suggest that the sturdier, more massive chelicerae of Ischyropsalis hellwigii, attributable to strong specialization on snails as prey, are associated with reduced Range of Motion. The less food-specialized species Ischyropsalis muellneri apparently requires higher flexibility of its chelicerae for prey capture, likely due to its restriction to cave ecosystems, where food availability is relatively scarce. We could show that virtual Range of Motion analyses in harvestmen chelicerae can play a pivotal role in understanding the theoretical feeding ecology and functional morphology of this group. This approach can be verified by in-vivo observations and measurements or extended to other arachnid taxa and other body parts.

Reproductive and developmental toxicity of α-terpineol in Wistar rats

Alpha-terpineol (α-T) is a type of monoterpenoid alcohol commonly present in essential oils, it contributes to a pleasant floral fragrance similar to that of lilacs. This research aimed to evaluate the impact of α-terpineol on the reproductive functions of both male and female rats, including gonadal activity, mating behavior, conception, conceptus development and parturition. Six male and female Wistar rats per group received α-terpineol through gavage at doses of 0, 75, 150 and 300 mg/kg/day. The study revealed changes in body weight gain inhibition, food consumption, azoospermia, decreased testosterone levels (0.7 ± 1.61 ng/mL, 0.7 ± 2.30 ng/mL) as well as histopathological variations in testis and epididymis among males exposed to doses of 150 and 300 mg/kg/day. Moreover, this exposure led to significantly decreased serum T4 levels in both adult males (21.85 ± 12.68 ng/mL, 16.20 ± 9.15 ng/mL) and dams (11.24 ± 12.37 ng/mL, 9.48 ± 11.74 ng/mL) at the dose range of 150 and 300 mg/kg/day without affecting TSH concentrations. In summary, the present study showed that α-terpineol induced reproductive toxicities in male rats. Therefore, a detailed toxicological assessment is highly recommended.

Short-Term Responsive Mating Intentions Increase with Estradiol and Testosterone across the Menstrual Cycle: Scale Development and an Observational Study

The extent to which estradiol, progesterone, and testosterone influence mating behavior across the menstrual cycle is unclear. The Proactive and Responsive Mating Strategies Scales (PARMSS) were developed to separately examine two specific components of sexuality and were used here to test divergent hormonal associations. Preliminary psychometric data (N = 364 females) suggest that both scales consist of one factor and demonstrate strong psychometric properties (internal consistency, test–retest reliability, and construct and convergent validity). The PARMSS were used in a repeated-measures observational study to examine the relationships between changes in endogenous hormone levels and both proactive and responsive mating intentions with potential new short-term or long-term partners in healthy pre-menopausal participants (N = 38). At two points in their cycle, participants provided salivary hormone samples in the laboratory and reported the likelihood of engaging in proactive and responsive behaviors with men in photos and vignettes. Participants reported greater responsive than proactive intentions. Increases in estradiol and testosterone across the cycle were associated with increases in short-term mating intentions, particularly responsivity to potential short-term relationship partners. No associations were found for intentions that were proactive or that involved potential long-term partners or for progesterone. Changes in the three hormones explained changes in short-term responsive mating intentions (22% of the variance). The results suggest (a) cyclical changes in estradiol and testosterone are differentially associated with changes in responsive vs. proactive mating intentions and (b) context-dependent changes (i.e., short-term vs. long-term mating intentions and possibly relationship status). The findings require replication with larger and diverse samples.

Evaluating the effects of short-term low temperature on the growth and development of Trichopria drosophilae based on the age–stage two-sex life table

BackgroundThe effects of low temperatures on parasitic wasps are crucial for maintaining farmland biodiversity and enhancing biological control, especially given the implications of global warming and frequent extreme cold events.MethodsWe studied the effects of different low temperatures (−8 ± 1 °C, −4 ± 1 °C, 0 ± 1 °C, 4 ± 1 °C, and 8 ± 1 °C) on the mating frequency and duration of male adults of Trichopria drosophilae and the number of pupae beaten by female adults, and constructed the age–stage two-sex life table of T. drosophilae.ResultsThis study found that male T. drosophilae adults exposed to low temperatures for 12 h significantly altered their mating behavior, peaking between 15:00 and 17:00. As the temperature dropped during the exposure, both the mating frequency of T. drosophilae and the duration of pupal beating were affected. The survival rate of female adults dropped from 39.55% at 8 °C to just 21.17% at −8 °C. Low-temperature treatment shortened the development period and lifespan for T. drosophilae adults. They developed 4.71 days faster and had a total lifespan that was 10.66 days shorter than those in the control group after being exposed to −8 °C. Furthermore, the average number of eggs laid by females at −8 °C was 4.46 less than that at 8 °C and 6.16 less than that in the control group, which laid an average of 21.55 eggs. The net reproductive rate (R0) of T. drosophilae decreased with lower temperatures, reaching a low of 23.64 at −8 °C. Conversely, the intrinsic growth rate (rm) actually increased as temperatures dropped, with the lowest value being 0.21 at −8 °C.ConclusionsThe findings indicate that short-term exposure to low temperatures hampers the growth and population increase of T. drosophilae, thereby reducing their effectiveness as biological control agents.Graphical

Sex-Specific Perching: Monitoring of Artificial Plants Reveals Dynamic Female-Biased Perching Behavior in the Black Soldier Fly, Hermetia illucens (Diptera: Stratiomyidae).

Artificial perches are implemented by many companies that mass-rear the black soldier fly (BSF), to emulate a natural breeding environment or provide additional surface area for flies to rest; however, basic information about perching behavior is lacking. This experiment tested the effect of adding 0.00, 0.04, 0.26, or 0.34 m2 of surface area to 0.93 m3 cages, each supplied with 90 male and 90 female adults. Female thoraxes marked with acrylic paint, and the number of perching flies of each sex were recorded over 6 d. A time-series analysis revealed the following: (a) females utilized perches 1.42 times more often than males across two trials; (b) especially in the morning where the difference could be as high as 2.56 times as great; (c) this decreased to 0.20-1.57 times more females than males by 1600 h; and (d) this cyclical pattern repeated each day throughout the week with a decreasing female-bias, starting from 2.41-times more females on day 1, which fell to 0.88-1.98-times more females than males on day 6. These dynamics are likely due to the presence of male flies engaging in aerial contests near ultraviolet lamps required for mating, especially during the early hours and early adulthood, aligning with and expanding prior knowledge of black soldier fly mating behavior.

Mating receptivity mediated by endosymbiont interactions in a haplodiploid thrips species.

Many arthropods carry maternally inherited endosymbionts that cause cytoplasmic incompatibility (CI), manifested as embryonic mortality in matings of infected males with uninfected females. Infected females, however, do not suffer this cost. Therefore, in populations with mixed endosymbiont infections, selection is expected to favour mechanisms that enable hosts to avoid or mitigate CI. This may include changes in mating behaviour, such as reduced female receptivity to mating and/or remating when approached by incompatible males. Here, we investigated mating behavioural traits in haplodiploid thrips naturally associated with two CI-inducing endosymbionts, Cardinium and Wolbachia. Compared with females with both endosymbionts, those with only Cardinium showed reduced receptivity to males carrying both. However, surprisingly, females without endosymbionts were not less receptive to incompatible males. Furthermore, in contrast to females without endosymbionts, females with Cardinium were far less likely to remate with incompatible than compatible males irrespective of the compatibility type of the first mating. Our results suggest that endosymbiont-specific sexual selection processes occur, whereby females carrying only Cardinium recognize Wolbachia in coinfected males to avoid CI. This may hinder a CI-driven Wolbachia spread. Endosymbiont-mediated mating behaviours may be crucial for the dynamics of CI-inducing endosymbionts and their application in pest management strategies.

A metabolomics approach reveals the pharmacological effects and mechanisms of Cistanche tubulosa stems and its combination with fluoxetine on depression in comorbid with sexual dysfunction

Ethnopharmacological relevanceThe dried succulent stems of Cistanche tubulosa (Schenk) Wight are utilized in traditional medicine for tonifying kidney yang, which have shown to be effective in alleviating depression-like behaviors or male sexual dysfunction, respectively. However, the pharmacological effects and mechanisms of C. tubulosa and its combinations in the treatment of depression in comorbid with sexual dysfunction remain unclear. Aim of the studyThis study aims to elucidate the pharmacological effects and mechanisms of C. tubulosa aqueous extract (CTE) and its combination with fluoxetine (FLX) on depression in comorbid with sexual dysfunction. Materials and methodsA mouse model of depression in comorbid with sexual dysfunction was created using the chronic unpredictable mild stress (CUMS) procedure. The therapeutic effects of CTE and its combination with FLX were assessed using depressive-like and mating behavior experiments, histopathological analysis, and hypothalamic-pituitary-gonadal (HPG) axis function evaluation. The mechanisms were explored by integrated serum and testicular metabolomics combined with network correlation analysis. ResultsCTE was confirmed to significantly improve depressive-like behaviors, reduce mating abilities, testicular histopathological damage, and HPG axis hormone secretion disorders in CUMS mice. Subsequently, mechanism exploration findings indicated that CTE might exert its effect by regulating potential efficacy-related biomarkers (isobutyrylglycine, citric acid, D-galactose) to improve certain metabolic pathways centered around steroid hormone biosynthesis and tricarboxylic acid (TCA) cycle. Furthermore, the combination of CTE and FLX exhibited stronger antidepressant effects than FLX alone, and ameliorated the exacerbated sexual dysfunction induced by FLX. These effects were achieved through the regulation of potential efficacy-related biomarkers (17α-hydroxypregnenolone, tetrahydrodeoxy-corticosterone, sphingosine, cortol, thymine, and L-histidine), thereby improving disorders in glycerophospholipid and histidine metabolism. ConclusionIn conclusion, the amelioration effects of CTE and its combination with FLX on depression in comorbid with sexual dysfunction were confirmed for the first time. This key mechanism may be achieved by modulating the levels of potential efficacy-related biomarkers, and then emphatically intervene in steroid hormone biosynthesis, TCA cycle, glycerophospholipid and histidine metabolism. The study offers a new perspective for the development and utilization of C. tubulosa.

A Case of Facultative Polygyny in an Enigmatic Monogamous Species, the European Nightjar (Caprimulgus europaeus).

In many socially monogamous bird species with biparental care, occasional social polygyny has been detected. We provide information about a case of facultative polygyny in the European Nightjar (Caprimulgus europaeus). The male nightjar (I96) formed a pair with two females (I95: the presumed primary female with whom he already bred since 2018; M042: the presumed secondary female, an inexperienced yearling). GPS and accelerometer data demonstrate how the male only sang in proximity of the primary nest, while assisting both females during incubation, as well as during the nestling period. When the male came to the nest, the primary and/or secondary female went foraging, but the secondary female received less assistance during incubation than the primary female, and her eggs were often left unattended. However, once the chicks of the secondary female hatched, male assistance suddenly increased, presumably at a cost to the primary female. Being only the second record of social polygyny in the European Nightjar, we do not have a direct explication for the occurrence of this polygynous event. We note that male density at the study site was lower than that observed in previous seasons. The male may have taken over the female that was initially paired to a neighbouring territory holder that then died. Alternatively, the inexperienced female might have mated with an already paired male, either because she was not aware of the mating status of the male, or because she could not find an unpaired male, or because mating with this paired male was better than mating with another unpaired male. In any case, the breeding ecology and mating behaviour of this crepuscular bird species remains little understood.

Differential expression of quick-to-court gene isoforms in Drosophila male and female

The quick-to-court (qtc) gene is expressed in both males and females but affects only the mating behavior of males, probably due to the different composition of isoforms in different sexes. We tested this hypothesis and examined the sex-specific expression of qtc transcripts in the tissues of male and female Oregon-R flies. It was found that some qtc transcripts, such as qtc-RM and qtc-RN, are testis-specific, while others like qtc-RH are found in ovaries but absent in testes. No sex-specific transcripts were identified in the brain, suggesting further investigation into specific brain structures may be needed. There is probably a complex regulation of qtc gene expression, which is potentially influenced by various factors in different tissues.

Thermal conditions alter the mating behaviour of males in a polygynous system

Abstract Males in polygynous systems may be facing a trade‐off between the traits that enhance reproductive success and the need to cope with environmental change. To secure mates, males invest into large bodies, lavish ornaments and costly activities, but these investments may be incompatible with future environments. As climatic change intensifies, thermal stressors could be disrupting the energy‐intensive pathways that historically have yielded mating opportunity. We evaluated how traits associated with social dominance interacted with environmental conditions to shape mating behaviour and opportunity in moose (Alces alces), a heat‐sensitive species in which southern populations live at the edge of their thermal tolerance. We anticipated that males with favourable characteristics (e.g. age, weaponry) would allocate more to reproduction, resulting in increased mating opportunity. We expected that warm temperatures would limit reproductive effort, especially as age and weapon size increased. We quantified mating tactics, effort, and opportunity for male moose ranging in age from 1.5 to 11.5 years. We used hidden Markov models to detect mating tactics, accelerometer data to quantify movement effort, and proximity to females as a proxy for mating opportunity. We modelled these mating dynamics as a function of age, weapon size, and ambient temperature. Warm temperatures exaggerated age‐related differences in time and effort allocated to reproductive movement. Heat disproportionately limited reproductive effort in old males, the ages that also had the greatest mating opportunity. Even though warm temperatures altered mating behaviour, they did not reduce mating opportunity. Across temperatures, mating opportunity was highest in prime‐age and old males, yet time and effort devoted to reproductive movement decreased with age. Climate change, which is increasing autumn temperatures, may increase variation in reproductive effort across ages and depress the movement of old males, who are typically the primary breeders. The discrepancy between behaviour and opportunity suggests that movement is not a reliable pathway to reproduction and emphasizes the advantages of energy‐saving strategies, especially as environments become more taxing for heat‐sensitive species. We reveal the limitations of movement effort in polygynous mating strategies and the susceptibility of this critical life history stage to environmental change. Read the free Plain Language Summary for this article on the Journal blog.

Hot males: thermal biology of males and females during coercive mating in water striders Gerris lacustris

Sexual conflict theory predicts that males that adopt coercive mating strategies impose costs to females during copulation. Nevertheless, conflicting mating strategies may also affect males, although such effects on males are often neglected in the literature. Here, we seek to understand whether male water striders (Gerris lacustris) experience higher body temperatures than females during coercive mating behavior. We we explored whether the water temperature affected male and female body temperature differently, considering that water contact by females might serve as a thermal regulator. We built generalized linear mixed models considering the male and female temperature as the dependent variables. Air temperature (as a proxy for solar radiation), water temperature, and sex were used as predictor variables. Our results suggest that males are warmer than females, and despite females coming into contact with water during skimming, this contact does not significantly contribute to lowering their body temperature or improving thermoregulation under the observed conditions. These findings provide novel insights into the thermal biology of water striders. Future studies should focus on addressing whether warmer temperatures confer some advantages to males, such as increased mobility and better ability to hold onto females or impose physiological constraints and fitness costs.