•Male-female conflict can arise when males can benefit from multiple mates.•Adjusting mating rate can resolve male–female conflict over multiple mates.•External fertilization can emphasize sperm ...management over sperm competition.•Continuous sperm production facilitates multiple within-pair mating.•Multiple within-pair mating can sometimes result from a “negotiated” mating rate.
Besides egg fertilization, females of many taxa obtain direct fitness benefits from male mates, such as food, protection or paternal care. But males often increase their own fitness by mating with several females, among which they distribute sperm along with the above-mentioned benefits, reducing the benefits to individual females. These diverging interests lead to a conflict in which each female may try to ensure male fidelity and get exclusive access to male-provided benefits. Here, we use a theoretical model to show how a female of an externally fertilizing species may achieve mate fidelity by soliciting copulations at such a rate that the male has insufficient sperm left to increase his fitness with additional females. We show that three alternative condition-dependent evolutionarily stable mating relationships emerge in this scenario, based on whether one mate’s preference for mating rate dominates, or the conflict is resolved by what amounts to negotiation. We demonstrate how these outcomes depend on some features of physiology, ecology, and behavior. In particular, a greater reproductive benefit to a female from exclusive access to a male partner—or the occasional tendency of females to withhold eggs during mating—can increase male fidelity; and continuous sperm regeneration rather than an initially-set stock of sperm allows for multiple within-pair mating across all three mating patterns.
Sirex noctilio F. is a woodwasp that develops within stressed and dying pine trees, Pinus spp. It is native to Eurasia and North Africa but has spread to other continents and has become a pest of ...pine plantations in the Southern Hemisphere. In nature, adults live for <2 wk, during which time males form leks. We investigated environmental and biological conditions related to mating of these woodwasps. We hypothesized that temperature, light, and size ratio of the sexes (male:female) influence mating receptivity. A total of 71 12-min mating trials, with 10males and 1 female in each trial, were conducted in outdoor cages. As a precursor to mating, a male would approach a female from behind and touch her with his antennae and, if the female was receptive, mating proceeded. Sirex noctilio mated more often at higher temperatures, but the size ratio of sexes and degree of cloud cover did not influence female receptivity tomating. Females that mated oftenmated multiple times (2.6 ± 0.2, mean ± SE; range 1–7), and numbers ofmatings increased with increasing temperature and was greatest during the last 4-min of the 12-min trials.
Observations of Chinese pangolin (Manis pentadactyla) in the wild are extremely rare and challenging because of their nocturnal and cryptic activity patterns and low population density. The present ...article reported the first field observation in eastern Taiwan, from October 4, 2012 to June 16, 2016, on the reproductive behavior of the Chinese pangolin based on the monitoring of a female (LF28) using radiotelemetry and camera traps. During this period, LF28 aged from 1-4.5 years old and gave two single-births, both took place in early December, at 3 and 4 years old, respectively. We recorded the entire 157 days of the first nursing period from parturition to maternal separation. For the second infant, the gestation period was estimated to be around 150 days based on the evidence that the pregnancy started in early Jul. 2015 and the offspring was born on Dec. 9, 2015. During the entire nursing period, LF28 frequently moved the offspring from one nursing burrow to another staying various durations ranging from 1 day to more than 35 days, and almost all (= 15/16) of these burrows were located in the core (MCP75) of LF28's home range. Started from the month of parturition and lasting throughout the whole nursing period, different adult males constantly visiting the nursing burrows were recorded. Mating behavior was recorded once outside the burrow in March, which provided evidence of the occurrence of post-partum estrus in this species. Delayed implantation was proposed based on the observation of a several months lag between copulation and the estimated pregnancy initiation date. The present study demonstrated the advantage of using remote technologies to learn the life history of resting fossorial species.
Mating outside the pair‐bond occurs frequently in socially monogamous birds, but the benefits that females gain from this behaviour remain debated. One hypothesis is that females engage in extra‐pair ...copulations (EPCs) to ensure that their clutch is fertilised in case their own mate is infertile, but evidence for this idea is scarce. We report on a case of an infertile male blue tit that bred in three successive years with three different females. In the first year, all eggs were sired by an extra‐pair male whereas in the second year all eggs were unfertilised and contained no sperm. In the third year, the female produced two clutches that were fertilised by an extra‐pair male, but – unlike ‘normal’ clutches – sperm numbers on the perivitelline membrane decreased rapidly over the laying sequence. Our findings show that blue tit females mated to an infertile male can escape reproductive failure by engaging in EPCs and support previous suggestions that EPCs in blue tits cease after the onset of egg laying.
Male fitness depends on the expression of costly traits involved in obtaining mates (pre-copulatory) and fertilization (post-copulatory). However, very little is known about the nutrient requirements ...for these traits and whether males compromise their diet to maximize one trait at the expense of another. Here we used Nutritional Geometry to investigate macronutrient requirements for pre- and post-copulatory traits in Drosophila, when males were the first or second to mate with females. We found no significant effects of male diet on sperm competitiveness. However, although males self-regulate their macronutrient intake at a protein-to-carbohydrate ratio ("P:C ratio") of 1:1.5, this ratio does not coincide with their optima for several key reproductive traits: both the short-term (~24 hr) rate of offspring production after a female's first mating, as well as the total offspring number sired when males were second to mate were maximized at a P:C ratio of 1:9, whereas male attractiveness (latency to mate), were maximised at a P:C ratio of 1:1. These results suggest a compromised optimum diet, and no single diet that simultaneously maximizes all male reproductive traits. The protein intake of first males also negatively affected female offspring production following remating, suggesting a long-term intersexual effect of male nutrition.
The genus Neotrogaspidia Lelej, 1996 is a small group of velvet ants with five species from the Australasian, Oriental and Palearctic Regions. The type species, N. pustulata (Smith, 1873) (♂♀), is ...the only Northeast Asian species known at present. In this paper, N. elpinice (Mickel, 1933), stat. resurr. et comb. nov. (♂♀) is resurrected from the junior synonym of N. pustulata. Two new combinations are proposed for N. circumcincta (André, 1896), comb. nov. (♂♀) from Orientidia Lelej, 1996 and N. recticarinata (Chen, 1957), comb. nov. (♂) from Trogaspidia Ashmead, 1899. New synonymies are proposed for N. elpinice with T. aestivalis Hammer, 1949, syn. nov. and T. maritima Chen, 1957, syn. nov., and N. circumcincta with T. yuliensis Tsuneki, 1972, syn. nov. and Krombeinidia agricola Williams, 2019, syn. nov. An updated genus diagnosis and a key to all described species are provided. New records include N. circumcincta from Laos and Vietnam, N. pustulata from North Korea, and N. recticarinata from Taiwan. The inflated endophallus of the male genitalia of N. pustulata is illustrated. A potential host record, habitat records and mating observations of Neotrogaspidia are presented. The historical process of formation of the distributional patterns of this genus in Northeast Asia is discussed.
Velvet ants possess varied dispersal ability across taxa stemming from alternative mating strategies. This paper reviewed the taxonomy of the genus Neotrogaspidia in Northeast Asia. The results highlighted the conflicting distributional patterns of velvet ant species on islands and potential of phoretic copulation for overseas dispersal.
Avian social and genetic mating systems are influenced by parental care roles as well as by reproductive opportunities. Alternative reproductive tactics, including conspecific brood parasitism and ...extra-pair mating, are predicted to be most common when females have access to potential host nests and when adults have access to potential mating partners, respectively. We tested these predictions in the facultatively colonial Hispaniolan woodpecker (
Melanerpes striatus
), a socially monogamous species with biparental care. Up to 12 pairs may nest concurrently in the same tree or, less frequently, two adjacent trees, potentially facilitating both conspecific brood parasitism and extra-pair mating. Contrary to our predictions, genotyping with single-nucleotide polymorphisms (SNPs) revealed no evidence of extra-pair paternity in either solitary or colonial nests: all 307 nestlings in 101 broods were matched to their social parents. Two instances of apparent conspecific brood parasitism were detected via changes in clutch size, but these could not be confirmed genetically since none of the apparently parasitic eggs survived to hatching. Therefore, if conspecific brood parasitism did occur, it was not a successful route to reproduction: parents fledged only their genetic offspring. These results suggest that reproductive opportunities alone are insufficient to favor alternative reproductive tactics, and that genetic monogamy can persist despite locally high densities of breeding pairs. Other life-history traits, including high levels of nest attendance and male parental care, may constrain parasitism and extra-pair mating in this long-lived tropical species.
Significance statement
High breeding density, a feature of colonial nesting, should increase opportunities for infidelity and conspecific brood parasitism because of the close proximity of potential extra-pair mates and parasitic females. Yet, we found that Hispaniolan woodpeckers, which nest both solitarily and colonially (two or more pairs in the same tree) in the same population, were genetically monogamous and lacked successful brood parasitism. Colonial nesting is exceptionally rare in the woodpecker family, which is also characterized by high investment in male parental care, including nocturnal incubation. The essential role of paternal care for successful reproduction in the Hispaniolan woodpecker might have selected against extra-pair mating and conspecific brood parasitism despite the apparent ample opportunities provided by nesting so close to others.
Extremely hot events (usually involving a few hours at extreme high temperatures in summer) are expected to increase in frequency in temperate regions under global warming. The impact of these events ...is generally overlooked in insect population prediction, since they are unlikely to cause widespread mortality, however reproduction may be affected by them. In this study, we examined such stress effects in the diamondback moth, Plutella xylostella. We simulated a single extreme hot day (maximum of 40°C lasting for 3, 4 or 5 h) increasingly experienced under field conditions. This event had no detrimental effects on immediate mortality, copulation duration, mating success, longevity or lifetime fecundity, but stressed females produced 21% (after 3 or 4 h) fewer hatched eggs because of a decline in the number and hatching success of eggs laid on the first two days. These negative effects on reproduction were no longer evident in the following days. Male heat exposure led to a similar but smaller effect on fertile egg production, and exposure extended pre-mating period in both sexes. Our results indicate that a single hot day can have detrimental effects on reproduction, particularly through maternal effects on egg hatching, and thereby influence the population dynamics of diamondback moth.
In rodents, sexual stimulation induces a positive affective state that is evaluated by the conditioned place preference (CPP) test. Opioids are released during sexual behavior and modulate the ...rewarding properties of this behavior. Prairie voles (Microtus ochrogaster) are a socially monogamous species, in which copulation with cohabitation for 6h induces a pair bond. However, the mating-induced reward state that could contribute to the establishment of the long-term pair bond has not been evaluated in this species. The present study aimed to determine whether one ejaculation or cohabitation with mating for 6h is rewarding for voles. We also evaluated whether this state is opioid dependent. Our results demonstrate that mating with one ejaculation and social cohabitation with mating for 6h induce a CPP in males, while exposure to a sexually receptive female without mating did not induce CPP. In the female vole, mating until one ejaculation, social cohabitation with mating, or exposure to a male without physical interaction for 6h did not induce CPP. To evaluate whether the rewarding state in males is opioid dependent, the antagonist naloxone was injected i.p. The administration of naloxone blocked the rewarding state induced by one ejaculation and by social cohabitation with mating. Our results demonstrate that in the prairie vole, on the basis of the CPP in the testing conditions used here, the stimulation received with one ejaculation and the mating conditions that lead to pair bonding formation may be rewarding for males, and this reward state is opioid dependent.
•In male prairie voles (M. ochrogaster), one ejaculation is rewarding.•In males, social cohabitation with mating for 6h that leads to pair bonding is rewarding.•In females, neither condition induces conditioned place preference.•The reward state induced by one ejaculation or 6h of mating is opioid dependent.
After a massive decline, the Griffon Vulture (Gyps fulvus) population in Bulgaria has now stabilised as a result of the hard work of conservation programmes, although it is still listed as an ...Endangered species (EN) in the country's Red Data Book. Due to a series of unfortunate events, another species - the Cinereous Vulture (Aegypius monachus) became extinct in Bulgaria and recovered only recently due to systematic re-introduction efforts. Along with the poor living conditions, a predisposing factor for the decreasing population of the vultures is the fact they hatch only a single egg; two may be laid on exceptions. The survival rate of the young is from medium to low. In that order, a method of double clutching has been applied in the hope of preserving and retrieving both of the vultures. This article aims to introduce the double clutching method in detail, as well as to show the results of its implementation into the breeding programme of the Cinereous Vulture and the Griffon Vulture at the Wildlife Rehabilitation and Breeding Centre of Green Balkans – Stara Zagora NGO. This research studies the time period 2019-2023. The purpose of this study is to compare the results of natural copulation and hatching and those of the double clutching method. The data taken are used for studies for both the Cinereous and the Griffon Vulture’s reproduction in correlation with their feeding programme and living conditions. The results of the study will be summarised into the following text for the purposes of shedding light on the positives of the double clutching method.
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