Copulatory pattern and behavior in a semi-captive population of Eld＇s deer

Male copulatory patterns, female multiple copulation and male post-copulatory guarding were studied in Eld＇s deer Cervus eldi in Datian National Nature Reserve, China. Mating behavior in 18 females and 11 males from a group of 61 semi-captive Eld＇s deer were observed. The majority （55.8%） of copulations occurred between 15：00-19：00 h. The ejaculatory mount was preceded by an average of 5.1 prior mounts. Successful copulation consisted of a single thrust with ejaculation during one intromission, with no lock. This copulatory pattern is classified as pattern No. 15 （no lock, no intravaginal thrusting, single intromission, and multiple ejaculation） and No. 16 （no lock, no intravaginal thrusting, single intromission, and single ejaculation） under Dewsbury＇s scheme （1972） and as No. 16 （no lock, no thrusting, single and brief intromission） under Dixson＇s classification （1998）. Copulation frequency was 1.5 ± 0.9 times for males/females with the same female/male per day. The duration of the final mount, which included ejaculation, was brief （3.4±1.3 s）, and ejaculation usually terminated copulation. Eleven females copulated more than once in this study： three of them copulated with several males （multi-male copulations） and the remainder copulated with a single male （repeated copulations）. Our results indicate that some female Eld＇s deer may seek multiple copulations to be a strategy to improve the genetic quality of their offspring or to avoid harassment. Post-copulatory guarding of females by males followed all copulations, with dominant males guarding for significantly longer than subordinate males. Dominant males appear to be more effective at post-copulatory guarding than subordinate males. Subordinate males engaged in a quicker pre-copulatory phase to improve their chances of finishing copulation before being forced to accede to dominant males [Current Zoology 57 （3）： 284-292, 2011].

Strategic adjustment of copulatory plug size in a nematode

Copulatory plugs(CP)are substances produced during copulation that block the genital openings of the female.In several species of Nematoda,males produce CP that are thought to impede female remating and thus sperm competition.The relatively large size of the CP in several nematodes,and its evolutionary loss in self-fertilizing populations of Caenorhabditis elegans,suggests that CP are costly to produce.If CP production is costly,the application of basic concepts of strategic ejaculation theory suggests a modulated allocation of CP in response to sperm competition risk.This hypothesis led us to predict that males perceiving a higher risk of sperm competition will produce larger CP.We tested these ideas with the entomopathogenic,gonochoristic nematode Rhabditis regina.Our first experiment provides evidence suggesting that production of CP is costly,because the size of CP is negatively affected by stressful conditions(high population density,small male adult size,and suboptimal food type).The results of our second experiment support the prediction that males adjust the size of CP to sperm competition risk:the average size of CP increased as the number of males competing for one female increased.Overall,our study supports the idea that in R.regina the production of CP is costly for males and that the size of the CP produced is influenced by sperm competition risk.

The duration of sociosexual behaviors in male meadow voles Microtus pennsylvanicus varies before, during, and after copulation

The behaviors that surround copulation are characterized as sociosexual behaviors. These behaviors displayed by males that are directed at females may include allogrooming, wrestling, chasing, approach, and time spent together. The data supported the hypothesis that the duration of sociosexual behaviors differs during the pre-copulatory, peri-copulatory, and post-copulatory phases of the mating bout in meadow voles. Voles spent more time approaching conspecifics during the pre- and peri-copulatory phases than during the post-copulatory phase. Voles spent more time allogrooming, wrestling, and chasing during the pre-copulatory phase than during the peri- and post-copulatory phases. Voles spent similar amounts of time together during the pre-, peri-, and post-copulatory phases. The data suggest that sociosexual behaviors displayed by males may be involved in set- ring the pace and temporal components of the mating bout. During the pre-copulatory phase particular behaviors by male voles may attract females, during the peri-copulatory phase some of these behaviors may stimulate or motivate the female to mate, and during the post-copulatory phase certain behaviors may prepare the male to mate again

Queens remate despite traumatic mating in stingless bees

Males can control female reproduction using genital plugs to impede access by rivals.In social bees,ants,and wasps,plugging may involve traumatic mating,with females being harmed.In stingless bees,chances are that plugs may promote ovarian activan,and are thought to ensure single mating—a general tendency among the social Hymenoptera.However,understanding on relationships between mating plugs,traumatic mating,and mating systems in stingless bees remains limited.To address this,we(1)compared mated queens of 7 Neotropical species to understand the patterns of copulatory marks in females and(2)compared pre-and post-mating genitalia of males and females in Melipona fasciculata to depict plug functional morphology.Data revealed an unprecedented consequence of mating in stingless bees:the characteristic marks left by mating plugs on female abdomens and the inferences that can be made from them.To our surprise,in 1 species M.fasciculata we found that queens retain the plug long after mating,and may carry it for the rest of their lives.All the other 6 species retained the plug for only a short period.Remated queens were only found in M.seminigra,whose multiple copulatory marks match previous findings of polyandry in this species.Our study shows that queens can remate,and suggests that male genital morphology may determine in part the time persistence of plugs.We conclude that traumatic mating plugs do not fully prevent remating in stingless bees and that mating systems are not uniform in this group.Nonetheless,exceptional cases of facultative polyandry in social insects—for example,when mating plugs fail—may confirm a general tendency for single mating in close link with efficient mating plugs.