The Role of Urine in Semiochemical Communication between Females and Males of Domestic Dog (Canis familiaris) during Estrus

This study aimed to assess the mechanisms of semiochemical signal detection in dogs. In the first experiment, five males were exposed to volatile semiochemicals emitted by a live female in estrus and the female’s urine sample collected during estrus. The odor of canine food and clean air were used as controls. In the second experiment, 25 males could directly sniff and lick the urine samples from females in estrus, from females in anestrus, from males and from humans, placed in a lineup. Sniffing, licking and salivation, as well as keeping dogs at different distances from the source of odor, were recorded in both experiments. Experiment 1 showed that food odor was sniffed by males longer than estrous urine. Volatile semiochemicals from females in estrus evoked interest in males but without visual cues did not cause overt symptoms of sexual arousal. In Experiment 2, the estrous urine evoked interest in males and provoked significantly longer sniffing. Licking accompanied by salivation was observed in all instances only during direct contact with estrous urine. The results suggest a complex character of detection of female reproductive status, in which both volatile and nonvolatile compounds emitted by females and present in female urine are involved.

Expression of Insulin-Like Growth Factor 1 (IGF-1) and Epidermal Growth Factor (EGF) Receptors and the Effect of IGF-1 and EGF on Androgen and Estrogen Release in the Myometrium of Pigs—In Vitro Study

Porcine myometrium possesses steroidogenic activity but its regulation is not well understood. It was hypothesized that the regulators of myometrial steroidogenesis are insulin-like growth factor 1 (IGF-1) and epidermal growth factor (EGF), which were found to modulate the steroidogenic activity of the endometrium and embryos. Myometrial slices were collected from gravid and nongravid pigs on days 10 or 11, 12 or 13 and 15 or 16 and studied for: (1) the relative abundance of IGF-1R and EGFR mRNA transcripts and proteins, to determine myometrial readiness to response growth factors treatment and (2) the effect of IGF-1 or EGF on the myometrial release of androstenedione (A4), testosterone (T), estrone (E1) and estradiol-17β (E2). The results showed that the relative expression and abundance of IGF-1R and EGFR in the myometrium were altered regarding the female reproductive status. During the estrous cycle, EGF increased myometrial release of A4 on days 12–13 and E2 on days 15–16. In gravid pigs (days 15–16), IGF-1 and EGF increased the E1 release. In conclusion: (1) porcine myometrium possesses the potential to respond to IGF-1 and EGF treatment, (2) EGF significantly increases myometrial A4 and E2 release in cyclic pigs, while IGF-1 and EGF increase the E1 release in gravid pigs.

Reproductive Factors and Risk of Spontaneous Abortion in the Jinchang Cohort

The aim of this study was to investigate the association between female reproductive status and risk of spontaneous abortion among female workers in the Jinchang Cohort. This study used data obtained from a baseline survey of the Jinchang Cohort Study of female workers in Jinchang Industry, the largest nickel production company in China. A standardized, structured questionnaire was used to collect the health status of 18,834 female workers employed by the company from 2011 to 2013. Spearman grade correlation analysis and logistic regression models were used to evaluate the association between female reproductive status and risk of spontaneous abortion. The incidence rate of spontaneous abortion was 6.89%, and fatigue was associated with the risk of spontaneous abortion. The number of pregnancies, age at primary birth and age at the last pregnancy were associated with an increased risk of spontaneous abortion (rs = 0.190, p = 0.000; rs = 0.092, p = 0.000; rs = 0.061, p = 0.000; respectively). In addition, there was a negative correlation between the number of artificial abortions and spontaneous abortions (rs = −0.129, p = 0.000). Female reproductive status was associated with an increased risk of spontaneous abortion in this cohort. More studies are needed to confirm this observed association.

The frequency of leg autotomy and its influence on survival in natural populations of the wolf spider Pardosa valens

Autotomy occurs when an animal intentionally sacrifices an appendage to escape predation or free a limb. While immediately beneficial, loss of an appendage can lead to a variety of future costs. In many spiders, leg autotomy is common; previous work has sometimes demonstrated autotomy costs in some behaviors, while other times, no costs of autotomy occur. We examined frequency of autotomy in two riparian zone populations of the wolf spider Pardosa valens Barnes, 1959 and then used both mark–recapture work at these sites and laboratory predation trials to determine whether autotomy affected survival. Autotomy occurred in 31% of spiders; males were more likely than females to have a missing leg, but female reproductive status (carrying an egg sac or not) was unrelated to leg loss status. At both sites, survival over 1 week in the field was significantly higher for intact spiders than for spiders missing a leg, for both sexes and both female reproductive states. Additionally, when we paired intact and autotomized spiders with a predator (the larger wolf spider Rabidosa santrita (Chamberlin & Ivie, 1942)), autotomized spiders were more likely to be attacked and eaten. Our results suggest that leg autotomy in P. valens leads to a significant future survival cost, and we discuss how this cost may affect males and females differently.

Female reproductive status affecting chimney characteristics and time allocation for surface activities in Uca rosea (Tweedie, 1937) (Brachyura, Ocypodidae)

We examined the effects of female reproductive status (ovigerous and non-ovigerous) on chimney characteristics and time allocation for surface activities in Uca rosea (Tweedie, 1937) (currently referred to as Tubuca rosea (Tweedie, 1937)). We investigated time spent on feeding, standing, in burrow, surface mating, walking, grooming, and digging of 13 ovigerous and 20 non-ovigerous females of similar-size and measured the diameter, width, and height of their chimneys. Chimneys of ovigerous females were wider and higher than those of non-ovigerous females, but chimney diameters did not differ. Ovigerous females spent less time on feeding and walking, but more time on standing, inside burrows, and mating than non-ovigerous females. Feeding rate/min did not differ between ovigerous and non-ovigerous females. This study reports, for the first time, that reproductive status of females affects chimney characteristics and time allocation for surface activities in U. rosea.

Social grooming among Indian short-nosed fruit bats

Social grooming is conspicuous in group-living mammals. Bats are gregarious and may groom each other, but the motivation for such social behaviour remains unclear. Here, we describe patterns and infer function of social grooming in tent-making Indian short-nosed fruit bats. Combining field and captivity observations, we found that males and their harem of females mutually groom and apply bodily secretions to one another in tight clusters. Mutual grooming is more commonly initiated by females, before emergence flight at dusk, and during the non-mating season. The within-harem association pattern suggests males may recognize female reproductive status via social grooming. Chemical analysis of the secretions applied during grooming revealed volatile organic compounds that may be involved in chemosensory-mediated communication and/or mate choice. These fruit bat harems were previously seen as simple aggregations, with limited interactions among individuals. Our findings suggest social grooming is multi-functional, with potential implications for the bats’ social lives.