Reproductive behaviour in free-ranging crested porcupine Hystrix cristata L., 1758

Previous data on crested porcupine reproduction biology were mostly collected in captivity or semi-captivity due to its elusive, burrowing and mainly nocturnal habits. Between 2017 and 2019 the reproductive behaviour (i.e., intrapair mounting and copulation, birth and parental care) of free-ranging crested porcupine was documented and described. Nightly rhythms of single and multiple mounting occurred throughout the year while only two copulation events were recorded. Three months after both copulation events, the birth of porcupettes (porcupine < 5 kg) was recorded. A stochastic phase characterized by an articulate courtship with distinct behavioural patterns always preceded each mounting event. After the stochastic phase, the presenting of the female evoked by Nose-Quill contact behaviour, occurred in 83.8% (n = 182) of mounting events, while in 16.1% (n = 35) a spontaneous presenting of the female occurred. The average duration of copulation lasted 24 s (SD = 7 s) with 17 thrusting (SD = 5.5 thrusting). Births of porcupettes occurred throughout the year from 1 to 3 times per pair per year and the litter size observed ranged from 1 to 2 porcupettes. The first emerging of porcupettes from burrow occurred at 10–15 days after birth. Parents and sub-adults of the family actively perform parental care and the permanence of sub-adults within the family (i.e., from birth to dispersal) resulted to be at least 1 year. This investigation provides new useful insights on porcupine reproductive behaviour in the wild. Such new knowledge may be useful to the management of porcupines in wild, semiwild and captive condition as well as to delineate the key habitat desiderata of this rodent.

Life history of the false flower mantid (Harpagomantis tricolor Linnaeus, 1758) (Mantodea: Galinthiadidae) and its distribution in southern Africa

The false flower mantid is the common name for the Mantodea species Harpagomantis tricolor (Linnaeus, 1758). This species uses camouflage as a defense mechanism. Limited information (Kaltenbach 1996, 1998) exists on its distribution in southern Africa or about its life history. This species, and Mantodea to an extent, are not usually included in biodiversity studies from this region. The aim of this study was to determine the distribution of this species in southern Africa based on museum collection records and to study the biology of Harpagomantis tricolor under captive breeding conditions. The distribution of Harpagomantis and its morphological variety, i.e., discolor, were determined utilising the historical insect collection records of seven national museums throughout South Africa. Field collected H. tricolor males and females were mated and reared under laboratory conditions to record their life history parameters of nymphal duration, oothecae structure, size and incubation duration, adult longevity, and sex ratio. The results of this study indicate that the mean duration of the lifecycle of H. tricolor is 191.33 ± 37.96 days. All but three H. tricolor individuals had five nymphal instars, and the mean duration of the nymphal stage was 140.20 ± 31.03 days. The mean duration of copulation was six hours, while the average incubation period of oothecae was 144.71 ± 9.33 days. These results indicate that oothecae of H. tricolor probably overwinter under field conditions and that males of this species have evolved various mechanisms to increase the likelihood of ensuring their own genetic offspring. This study bridges the gap in rudimental research in which Mantodea, in general, has been overlooked and establishes a basis on which ecological interactions, habitat preferences, and imminent threats to H. tricolor can be established.

Increased copulation duration does not necessarily reflect a proportional increase in the number of transferred spermatozoa

Post-copulatory sexual selection research tends to focus on the numerous adaptations that have evolved to increase the chances of donated spermatozoa fertilizing oocytes. Even though fertilization obviously directly depends on the presence of sufficient, viable spermatozoa, the quantification of the sperm transfer process itself has not received the attention it deserves. Here, we present experimental work on a simultaneously hermaphroditic snail in combination with a review of the literature focussing on the relationship between the duration of copulation and the number of sperm that are transferred. Based on classical work, this relationship is often assumed to be linear, but as we show here this need not be the case. Both our experimental data and the reviewed literature indicate that there are clear instances where the process of sperm transfer is not a linear process, i.e., longer copulation duration does not necessarily imply more transfer of sperm. As we point out, there seems to be a bias in the literature towards investigating this in insects, but other animal groups in which this has been investigated do show similar relationships. To conclude, we discuss how the specific patterns of sperm transfer that have been reported can be biologically interpreted and we caution that simply using copulation duration as a proxy for the number of sperm transferred can be misleading.

Testing hypotheses for the function of the carnivoran baculum using finite-element analysis

The baculum (os penis) is a mineralized bone within the glans of the mammalian penis and is one of the most morphologically diverse structures in the mammal skeleton. Recent experimental work provides compelling evidence for sexual selection shaping the baculum, yet the functional mechanism by which this occurs remains unknown. Previous studies have tested biomechanical hypotheses for the role of the baculum based on simple metrics such as length and diameter, ignoring the wealth of additional shape complexity present. For the first time, to our knowledge, we apply a computational simulation approach (finite-element analysis; FEA) to quantify the three-dimensional biomechanical performance of carnivoran bacula (n= 74) based upon high-resolution micro-computed tomography scans. We find a marginally significant positive correlation between sexual size dimorphism and baculum stress under compressive loading, counter to the ‘vaginal friction’ hypothesis of bacula becoming more robust to overcome resistance during initial intromission. However, a highly significant negative relationship exists between intromission duration and baculum stress under dorsoventral bending. Furthermore, additional FEA simulations confirm that the presence of a ventral groove would reduce deformation of the urethra. We take this as evidence in support of the ‘prolonged intromission’ hypothesis, suggesting the carnivoran baculum has evolved in response to pressures on the duration of copulation and protection of the urethra.

Mate availability does not influence mating strategies in males of the sexually cannibalistic spiderArgiope bruennichi

BackgroundSexual selection theory predicts that male investment in a current female should be a function of female density and male competition. While many studies have focused on male competition, the impact of female density on male mating investment has been widely neglected. Here, we aimed to close this gap and tested effects of mate density on male mating decisions in the orb-web spiderArgiope bruennichi. Males of this species mutilate their genitalia during copulation, which reduces sperm competition and limits their mating rate to a maximum of two females (bigyny). The mating rate is frequently further reduced by female aggression and cannibalization. Males can reduce the risk of cannibalism if they jump off the female in time, but will then transfer fewer sperm. An alternative solution of this trade-off is to copulate longer, commit self-sacrifice and secure higher minimal paternity. The self-sacrificial strategy may be adaptive if prospective mating chances are uncertain. InA. bruennichi, this uncertainty may arise from quick changes in population dynamics. Therefore, we expected that males would immediately respond to information about low or high mate availability and opt for self-sacrifice after a single copulation under low mate availability. If male survival depends on information about prospective mating chances, we further predicted that under high mate availability, we would find a higher rate of males that leave the first mating partner to follow a bigynous mating strategy.MethodWe used naïve males and compared their mating decisions among two treatments that differed in the number of signalling females. In the high mate availability treatment, males perceived pheromone signals from four adult, virgin females, while in the low mate availability treatment only one of four females was adult and virgin and the other three were penultimate and unreceptive.ResultsMales took more time to start mate searching if mate availability was low. However, a self-sacrificial strategy was not more likely under low mate availability. We found no effects of treatment on the duration of copulation, the probability to survive the first copulation or the probability of bigyny. Interestingly, survival chances depended on male size and were higher in small males.DiscussionOur results do not support the hypothesis that mate density variation affects male mating investment, although they clearly perceived mate density, which they presumably assessed by pheromone quantity. One reason for the absence of male adjustments to mating tactics could be that adaptations to survive female attacks veil adaptations that facilitate mating decisions.

Role of aqueous extract of Crocus sativus to improvement of sexual dysfunctions induced by imipramine in male mice

The present study was carried out to focus light on the possible improvement and enhancement of functional performance of male mice sexual activities by using the aqueous extract of Crocus sativus. Several pharmaceutical drugs affect sexual activities and upset the sexual desire sequence that can lead to impotence or loss libido, example of these drugs are tricyclic antidepressant such as imipramine. To achieve this goal, twenty adult albino male mice were used, which were randomly divided into equal four experimental groups. The first group was given 10 mg/kg B.W. imipramine, the second group was given 100 mg/kg B.W. aqueous extract of Crocus sativus, and the third group was given 100 mg/ kg B.W. Crocus sativus aqueous extract and 10 mg/ kg B.W. imipramine, while the fourth group served as control, which was given D.W. In all groups the doses were given orally by stomach tube at 0.1 ml/10 g. B.W. for 30 days. The recorded parameters were; latency of copulation (second), frequency of copulation (per-hour), and duration of copulation (second). At day thirty blood samples were collected to determine the hormonal levels of luteinizing and testosterone hormones and the testis were obtained for histopathological processing .The results of sexual activity measured parameters showed significant decrease (P<0.05) in latency of copulation and significant increase in both frequency of copulation, and duration of copulation in the groups given aqueous extract of Crocus sativus and that given aqueous extract of Crocus sativus and imipramine as compared with imipramine and control groups. While results of hormonal levels showed significant increase (P<0.05) in both groups of Crocus sativus aqueous extract and imipramine as compared with imipramine only and control groups. On bases of these results, it can be concluded that the sexual activities of male mice given imipramine tend to be improved and returned when administered with aqueous extract of Crocus sativus.

Male–female interactions drive the (un)repeatability of copula duration in an insect

Across the animal kingdom the duration of copulation varies enormously from a few seconds to several days. Functional explanations for this variation are largely embedded within sperm competition theory in which males modulate the duration of copula in order to optimize their fitness. However, copulation is the union of two protagonists which are likely to have separate and often conflicting reproductive interests, yet few experimental designs specifically assess the effect of male–female interactions on the duration of copulation. This can result in inexact assertions over which sex controls copulatory behaviour. Here we analyse the repeatability of copulatory behaviour in the seed beetle Callosobruchus maculatus to determine which sex exerts primary influence over copulation duration. In C. maculatus , copulation follows two distinct phases: an initial quiescent phase followed by a period of vigorous female kicking behaviour that culminates in the termination of copulation. When males or females copulated with several novel mates, copulatory behaviour was not significantly repeatable. By contrast, when males or females mated repeatedly with the same mate, copula duration was repeatable. These data suggest copulatory behaviour in C. maculatus to be largely the product of male–female interactions rather than the consistent, sex-specific modulation of copula duration of one protagonist in response to the phenotypic variation presented by the other protagonist.