Geographic Disparity in Chronic Obstructive Pulmonary Disease (COPD) Mortality Rates among the Taiwan Population

Chronic obstructive pulmonary disease (COPD) causes a high disease burden among the elderly worldwide. In Taiwan, the long-term temporal trend of COPD mortality is declining, but the geographical disparity of the disease is not yet known. Nationwide COPD age-adjusted mortality at the township level during 1999–2007 is used for elucidating the geographical distribution of the disease. With an ordinary least squares (OLS) model and geographically weighted regression (GWR), the ecologic risk factors such as smoking rate, area deprivation index, tuberculosis exposure, percentage of aborigines, density of health care facilities, air pollution and altitude are all considered in both models to evaluate their effects on mortality. Global and local Moran’s I are used for examining their spatial autocorrelation and identifying clusters. During the study period, the COPD age-adjusted mortality rates in males declined from 26.83 to 19.67 per 100,000 population, and those in females declined from 8.98 to 5.70 per 100,000 population. Overall, males’ COPD mortality rate was around three times higher than females’. In the results of GWR, the median coefficients of smoking rate, the percentage of aborigines, PM₁₀ and the altitude are positively correlated with COPD mortality in males and females. The median value of density of health care facilities is negatively correlated with COPD mortality. The overall adjusted R-squares are about 20% higher in the GWR model than in the OLS model. The local Moran’s I of the GWR’s residuals reflected the consistent high-high cluster in southern Taiwan. The findings indicate that geographical disparities in COPD mortality exist. Future epidemiological investigation is required to understand the specific risk factors within the clustering areas.     

Sex differences in the termination of social play in cats

Sixteen measures of social play between kittens were found to decrease significantly between 12 and 16 weeks of age. Behaviour was little influenced by the presence of the mother during this time. Although males' rates of behaviour did not differ from females' rates when the sexes were compared regardless of group composition, males from all-male groups played at higher rates than females from all-female groups. Females' rates of behaviour declined as the number of male companions decreased. Males' behaviour was little influenced by the number of females in the group. Females with male companions behaved more like males than did females with no male companions, but this was not because they directed behaviour to brothers at higher rates than to sisters.     

Models on butterfly protandry: Virgin females are at risk to die

Current models on protandry in butterflies assume that females are mated instantaneously upon eclosion. However, for most butterfly species this assumption is not realistic. In this paper a model is formulated in which the mating rate depends on both male and female density. Given the female presence curve, protandry is an evolutionarily stable strategy (ESS) for males. The evolutionarily stable amount of protandry decreases with increasing death rate and decreasing encounter rate. Given the male presence curve, protandry also is an ESS for females. However, male and female ESS are not identical; moreover, in the present model a simultaneous ESS does not exist. Protandry critically depends on the assumption that females mate only once, whereas males are capable of multiple mating. If females too are capable of multiple mating, absence of protandry is the ESS for males as well as females. The model predicts that protandry depends on population density: protandry should be more pronounced in populations with high density than in populations with low density. Protandry also depends on sex ratio. It becomes more pronounced when the proportion of males among emerging adults increases.     

Mortality trajectory analysis reveals the drivers of sex-specific epidemiology in natural wildlife–disease interactions

In animal populations, males are commonly more susceptible to disease-induced mortality than females. However, three competing mechanisms can cause this sex bias: weak males may simultaneously be more prone to exposure to infection and mortality; being ‘male’ may be an imperfect proxy for the underlying driver of disease-induced mortality; or males may experience increased severity of disease-induced effects compared with females. Here, we infer the drivers of sex-specific epidemiology by decomposing fixed mortality rates into mortality trajectories and comparing their parameters. We applied Bayesian survival trajectory analysis to a 22-year longitudinal study of a population of badgers (Meles meles) naturally infected with bovine tuberculosis (bTB). At the point of infection, infected male and female badgers had equal mortality risk, refuting the hypothesis that acquisition of infection occurs in males with coincidentally high mortality. Males and females exhibited similar levels of heterogeneity in mortality risk, refuting the hypothesis that maleness is only a proxy for disease susceptibility. Instead, sex differences were caused by a more rapid increase in male mortality rates following infection. Males are indeed more susceptible to bTB, probably due to immunological differences between the sexes. We recommend this mortality trajectory approach for the study of infection in animal populations.     

Pupation site and emergence time influence the mating success of bagworm females,Oiketicus kirbyi

In commercial oil palm plantations in Costa Rica, we tested the hypotheses that pupation site and emergence time affect the mating success of protogynous female bagworms,Oiketicus kirbyi (Guilding) (Lepidoptera: Psychidae). Greater proportions of female than male pupae on upper leaves of oil palms and greater proportions of mated females in the upper rather than lower crown strata support the hypothesis that selection of pupation site by female larvae influences the mating success of adults. Increasing captures of males with increasing trap height further suggest that enhanced mating success of females in tree tops may be attributed either to most effective dissemination of sex pheromone on higher sites, or to males foraging predominantly in the upper strata of oil palms. As the majority of females pupated in the middle rather than upper crown of oil palms, selection of pupation site by females may be affected by additional as yet unknown factors. Emergence of females significntly preceded emergence of males. Increasing proportions of mated females throughout the emergence seasons probably resulted from an increased ‘availability’ of males. In tropical rainforests with local variations inO. kirbyi developmental time and stage, protogyny may represent an evolutionary strategy that furthers outbreeding.     

Odour cues from suitors’ nests determine mating success in a fish

Animals use a range of sensory cues for finding food, avoiding predators and choosing mates. In this regard, the aquatic environment is particularly suitable for the use of olfactory and other chemical cues. Nevertheless, mate choice research, even on aquatic organisms, has focused on visual signals, while chemical cues relevant in sexual selection have been assumed to be ‘intrinsic’ excretions of mate candidates. Here, using the sand goby Pomatoschistus minutus, a small fish with paternal egg care, we investigated the possibility that ‘extrinsic’ chemical cues in the males’ nests could also have a significant contribution to mating success. We found that females strongly avoided laying eggs into nests subject to the odour of Saprolegnia water moulds (an egg infection) and that this effect was independent of the females’ initial, visually based preference for males. To the best of our knowledge, this is the first study to show that chemical cues related to parental failure can play a large role in sexual selection.     

Low Incidence of Miscarriage Induced by the Scent of Male Littermates of Original Mates: Male Kinship Reduces the Bruce Effect in Female Mice,Mus musculus

The scent of a novel male can elicit pregnancy block in recently mated female mice (Mus musculus), a phenomenon known as the Bruce effect. Despite abundant literature on the Bruce effect in rodents, it remains unclear whether males related to a female’s original mate can induce the Bruce effect in out-bred, communally living mice. We investigated this question using Kunming (KM) male mice of varying genetic relatedness. Recently mated females were subjected to three treatments: exposure to the urine of the mate, urine of the mate’s male littermate, and urine of a male unrelated to the mate. It was found that the urine of male littermates of the females’ mates did not elicit more pregnancy block than that of the females’ mates. However, the urine of novel males caused a higher rate of female miscarriage than that of the females’ mates. By using a habituation-dishabituation paradigm, we found that unmated females could discriminate the urine scents of two male littermates from those of a novel male unrelated to the littermates. To understand how females use urinary cues to discriminate between males with different genetic relationships, we used gas chromatography coupled with mass spectrometry (GC-MS) to examine the volatile composition of urine from males with varying relatedness. It was found that KM male littermates shared similar volatile compositions in their urine. Our results suggest that male kinship reduces the Bruce effect in female KM mice, and provide additional evidence for mate choice being partly mediated by the Bruce effect in KM mice.     

Money Affects Theory of Mind Differently by Gender

Theory of Mind (ToM) ─ the ability to understand other’s thoughts, intentions, and emotions ─ is important for navigating interpersonal relationships, avoiding conflict, and empathizing. Prior research has identified many factors that affect one’s ToM ability, but little work has examined how different kinds of monetary incentives affect ToM ability. We ask: Does money affect ToM ability? If so, how does the effect depend on the structure of monetary incentives? How do the differences depend on gender? We hypothesize that money will affect ToM ability differently by gender: monetary rewards increase males’ motivation to express ToM ability while simultaneously crowding out females’ motivation. This prediction is confirmed in an experiment that varies the structure of monetary rewards for correct answers in the Reading the Mind in the Eyes Test (RMET). RMET scores decrease for females and increase for males with individual payments, and this effect is stronger with competitively-structured payments. RMET scores do not significantly change when monetary earnings go to a charity. Whether money improves or hinders ToM ability, and, hence, success in social interactions, thus depends on the interaction of gender and monetary incentive structure.     

Ranging behaviour of roe deer in an experimental high-density population: Are females territorial?

We studied the ranging behaviour and spatial relationships between seven roe deer during more than 4 years in a partly wooded 14.2-ha enclosure. The animals (three young males, four adult females) were monitored with GPS telemetry collars. As expected, the surface area and overlap of the males’ bimonthly ranges decreased, and the distance between their arithmetic centres increased, as they became adult and, for two of them, territorial. Unexpectedly, females also tended to space out, the surface area and overlap of their bimonthly ranges being minimal in May to June, i.e. during the birth period. The distance between their arithmetic centres reached its maximum at the same time. Overlap between females’ ranges was consistently lower than those between males and females’ ranges, or between 1-year old males’ ranges. Our results raise the questions of female seasonal territoriality and of independence of the spacing systems of the two sexes in roe deer.     

Infant Mortality Risk and Paternity Certainty Are Associated with Postnatal Maternal Behavior toward Adult Male Mountain Gorillas (Gorilla beringei beringei)

Sexually selected infanticide is an important source of infant mortality in many mammalian species. In species with long-term male-female associations, females may benefit from male protection against infanticidal outsiders. We tested whether mountain gorilla (Gorilla beringei beringei) mothers in single and multi-male groups monitored by the Dian Fossey Gorilla Fund’s Karisoke Research Center actively facilitated interactions between their infants and a potentially protective male. We also evaluated the criteria mothers in multi-male groups used to choose a preferred male social partner. In single male groups, where infanticide risk and paternity certainty are high, females with infants <1 year old spent more time near and affiliated more with males than females without young infants. In multi-male groups, where infanticide rates and paternity certainty are lower, mothers with new infants exhibited few behavioral changes toward males. The sole notable change was that females with young infants proportionally increased their time near males they previously spent little time near when compared to males they had previously preferred, perhaps to encourage paternity uncertainty and deter aggression. Rank was a much better predictor of females’ social partner choice than paternity. Older infants (2–3 years) in multi-male groups mirrored their mothers’ preferences for individual male social partners; 89% spent the most time in close proximity to the male their mother had spent the most time near when they were <1 year old. Observed discrepancies between female behavior in single and multi-male groups likely reflect different levels of postpartum intersexual conflict; in groups where paternity certainty and infanticide risk are both high, male-female interests align and females behave accordingly. This highlights the importance of considering individual and group-level variation when evaluating intersexual conflict across the reproductive cycle.     

Female Choice or Male Sex Drive? The Advantages of Male Body Size during Mating in Drosophila Melanogaster

The mating success of larger male Drosophila melanogaster in the laboratory and the wild has been traditionally been explained by female choice, even though the reasons are generally hard to reconcile. Female choice can explain this success by virtue of females taking less time to mate with preferred males, but so can the more aggressive or persistent courtships efforts of large males. Since mating is a negotiation between the two sexes, the behaviors of both are likely to interact and influence mating outcomes. Using a series of assays, we explored these negotiations by testing for the relative influence of male behaviors and its effect on influencing female courtship arousal threshold, which is the time taken for females to accept copulation. Our results show that large males indeed have higher copulation success compared to smaller males. Competition between two males or an increasing number of males had no influence on female sexual arousal threshold;—females therefore may have a relatively fixed ‘arousal threshold’ that must be reached before they are ready to mate, and larger males appear to be able to manipulate this threshold sooner. On the other hand, the females’ physiological and behavioral state drastically influences mating; once females have crossed the courtship arousal threshold they take less time to mate and mate indiscriminately with large and small males. Mating quicker with larger males may be misconstrued to be due to female choice; our results suggest that the mating advantage of larger males may be more a result of heightened male activity and relatively less of female choice. Body size per se may not be a trait under selection by female choice, but size likely amplifies male activity and signal outputs in courtship, allowing them to influence female arousal threshold faster.     

Male Seminal Fluid Substances Affect Sperm Competition Success and Female Reproductive Behavior in a Seed Beetle

Male seminal fluid proteins are known to affect female reproductive behavior and physiology by reducing mating receptivity and by increasing egg production rates. Such substances are also though to increase the competitive fertilization success of males, but the empirical foundation for this tenet is restricted. Here, we examined the effects of injections of size-fractioned protein extracts from male reproductive organs on both male competitive fertilization success (i.e., P2 in double mating experiments) and female reproduction in the seed beetle Callosobruchus maculatus. We found that extracts of male seminal vesicles and ejaculatory ducts increased competitive fertilization success when males mated with females 1 day after the females’ initial mating, while extracts from accessory glands and testes increased competitive fertilization success when males mated with females 2 days after the females’ initial mating. Moreover, different size fractions of seminal fluid proteins had distinct and partly antagonistic effects on male competitive fertilization success. Collectively, our experiments show that several different seminal fluid proteins, deriving from different parts in the male reproductive tract and of different molecular weight, affect male competitive fertilization success in C. maculatus. Our results highlight the diverse effects of seminal fluid proteins and show that the function of such proteins can be contingent upon female mating status. We also document effects of different size fractions on female mating receptivity and egg laying rates, which can serve as a basis for future efforts to identify the molecular identity of seminal fluid proteins and their function in this model species.     

Juvenile social experience affects pairing success at adulthood: congruence with the loser effect?

Social interactions with adults are often critical for the development of mating behaviours. However, the potential role of other primary social partners such as juvenile counterparts is rarely considered. Most interestingly, it is not known whether interactions with juvenile females improve males’ courtship and whether, similar to the winner and loser effects in a fighting context—outcome of these interactions shapes males’ behaviour in future encounters. We investigated the combined effects of male quality and juvenile social experience on pairing success at adulthood in zebra finches (Taeniopygia guttata). We manipulated brood size to alter male quality and then placed males in either same- or mixed-sex juvenile dyads until adulthood. We found that males from reduced broods obtained more copulations and males from mixed-sex dyads had more complete courtships. Furthermore, independent of their quality, males that failed to pair with juvenile females, but not juvenile males, had a lower pairing success at adulthood. Our study shows that negative social experience with peers during adolescence may be a potent determinant of pairing success that can override the effects of early environmental conditions on male attractiveness and thereby supports the occurrence of an analogous process to the loser effect in a mating context.     

Effects of temperature on life‐history traits of the newly invasive fall armyworm,Spodoptera frugiperda in Southeast China

In mid‐May, 2019, the fall armyworm (FAW) Spodoptera frugiperda invaded Jiangxi Province, China, and caused extensive damage to corn crops. However, little attention has been given to the life‐history traits of the FAW. In the present study, we systematically investigated the life‐history traits of the newly invasive FAW on corn leaves at 19, 22, 25, 28, and 31°C under a photoperiod of LD 15:9 hr. The FAW thrived on the corn leaves with short developmental periods, high survival rates of larvae and pupae, very high mating success rates, and high fecundity. The pupal developmental stage was significantly longer in males than females at all temperatures, thus resulting in a protogyny phenomenon. The pupal weight was heaviest after a relatively shorter larval development stage at a higher temperature (25°C); thus, the FAW did not follow the temperature–size rule. Females were smaller than males, indicating sexual size dimorphism. A small proportion of females delayed their pre‐oviposition period and began to lay eggs on the 7th to 9th day after adult emergence. There were positive relationships between pupal weight and larval developmental time and between adult weight and fecundity. There was a negative relationship between fecundity and longevity. These findings can help us to predict the population dynamics of the FAW on corn and to develop a suitable and practical management strategy.     

Growth and Development in Wild Owl Monkeys (<Emphasis Type="Italic">Aotus azarai</Emphasis>) of Argentina

Life history predicts that in sexually dimorphic species in which males are the larger sex, males should reach sexual maturity later than females (or vice versa if females are the larger sex). The corresponding prediction that in sexually monomorphic species maturational rates will differ little between the sexes has rarely been tested. We report here sex differences in growth and development to adulthood for 70 female and 69 male wild owl monkeys (Aotus azarai). In addition, using evidence from natal dispersal and first reproduction (mean: 74 mo) for 7 individuals of known age, we assigned ages to categories: infant, 0–6 mo; juvenile, 6.1–24 mo; subadult, 24.1–48 mo; adult >48 mo. We compared von Bertalanffy growth curves and growth rates derived from linear piecewise regressions for juvenile and subadult females and males. Growth rates did not differ between the sexes, although juvenile females were slightly longer than males. Females reached maximum maxillary canine height at ca. 2 yr, about a year earlier than males, and females’ maxillary canines were shorter than males’. Thus apart from canine eruption and possibly crown–rump length, the development of Azara’s owl monkeys conforms to the prediction by life history that in monomorphic species the sexes should develop at similar paces.     

Size- and density-dependent reproductive success of bagworms, Metisa plana

A study conducted in a Malaysian plantation of oil palm over 5 consecutive generations of bagworms, Metisa plana (Walker) (Lepidoptera: Psychidae), evaluated extent and causes of variability for 3 components of reproductive success: pupal mortality, mating success and fecundity. The population of M. plana in the experimental site exhibited cycles of 70–80 days with discrete generations. Females emerged before males during all generations. Relatively large proportions of M. plana did not reproduce, either because they did not survive as pupa or (for females) mate as adult. Occurrence of unmated female bagworms may be attributed to complex mating procedure, short lifespan of females, limited mating capacity of males, protogyny inducing female-biased operational sex-ratio, and/or flightlessness per se constraining mating success of females. Size attained at pupation is a significant component of reproductive success, with large individuals having greatest survival during pupal stage, mating success and fecundity. Population density also influenced reproductive success of M. plana: female and (to a lesser extent) male larvae on crowded palms attained small size at pupation; survival of pupae was density-dependent during 2 generations for females and density-independent during 5 generations for males; mating success of females was inverse density-dependent during 4 generations. Size- and density-dependent mating success of females may be attributed to mate choice by males, size-dependent pheromone production by and longevity of females, and/or disorientation of mate-seeking males around heavily infested palms. Long-term studies are needed to determine whether and to what extent attributes of oil palm, seasonal fluctuations of abiotic factors and inter-generational variations of reproductive success influence population dynamics of M. plana.     

Mating system and size advantage of male mating in the protogynous swamp eel Monopterus albus with paternal care

In fish with paternal care, protogynous sex change (female to male) is rare and has only been reported from species with haremic polygyny. The swamp eel, Monopterus albus, is a protogynous fish with paternal care, but little is known about its mating system. To understand protogyny in this species, we examined the mating system and male size advantage in mating in M. albus under semi-natural condition. Females swam over wide ranges and visited multiple male nests. Males defended a narrow territory around nests against other males that approached nests; at these nests, males courted and accepted visiting females. After spawning inside nests, caring males continued to perform courtship activities, and multiple breeding was observed. These observations suggest that the M. albus mating system is male-territory-visiting (MTV)-polygamy. Larger males had nests, and mated more frequently compared with small males. Because small initial males of this species are not found in nature, and because M. albus does not engage in sneaking tactics, larger nesting males do not suffer from reproductive parasitism. Thus, protogyny in this fish is likely consistent with the predictions of the size-advantage model. Biting attacks by territorial males of this predatory fish seriously wounded intruding males, occasionally resulting in the death of the intruder. We discuss the possibility that sexual differences in mortality rates in small fish may facilitate the evolution of protogyny in this species. Protogyny of the swamp eel is, to our knowledge, the first example of an MTV-polygamous mating system in a fish with paternal care.     

Co-existence of subadult males and females as alternative tactics of breeding post acquisition in a monogamous and protandrous anemonefish

Summary The monogamous and protandrous anemonefish,Amphiprion clarkii, utilizes only large host sea anemones as breeding sites. Under conditions of breeding site shortage, an important strategy for unmated fish may be to prepare themselves to enter quickly a breeding site from which a breeding male or female has recently disappeared. There are two types of subadults. Some juveniles become subadult males, which can change either to male or female afterwards, but others become subadult females, which can change only to female. Subadult females seem to acquire female posts more easily than subadult males. We develop an ESS model which evaluates the future reproductive success of subadult females and subadult males and test whether coexistence of subadult males and females can be interpreted as adaptive alternative tactics, using field data from two populations. The model predicts that if mortality does not differ between adult males and females the frequency for juveniles to become subadult females should be equal to the proportion of breeding post acquisition by subadult females among that by all subadults. The model also predicts that if mortality does not differ between subadult males and females, nor in adults, the frequency of subadult females among all subadults should be equal to the proportion of post acquisition. The model, with data from two study sites, suggests that alternative life-history pathways found inA. clarkii have evolved through adaptive tactics of breeding post acquisition.     

The evolution of parental care in the context of sexual selection: a critical reassessment of parental investment theory

Males and females are often defined by differences in their energetic investment in gametes. In most sexual species, females produce few large ova, whereas males produce many tiny sperm. This difference in initial parental investment is presumed to exert a fundamental influence on sex differences in mating and parental behavior, resulting in a taxonomic bias toward parental care in females and away from parental care in males. In this article, we reexamine the logic of this argument as well as the evolutionarily stable strategy (ESS) theory often used to substantiate it. We show that the classic ESS model, which contrasts parental care with offspring desertion, violates the necessary relationship between mean male and female fitness. When the constraint of equal male and female mean fitness is correctly incorporated into the ESS model, its results are congruent with those of evolutionary genetic theory for the evolution of genes with direct and indirect effects. Male parental care evolves whenever half the magnitude of the indirect effect of paternal care on offspring viability exceeds the direct effect of additional mating success gained by desertion. When the converse is true, desertion invades and spreads. In the absence of a genetic correlation between the sexes, the evolution of paternal care is independent of maternal care. Theories based on sex differences in gametic investment make no such specific predictions. We discuss whether inferences about the evolution of sex differences in parental care can hold if the ESS theory on which they are based contains internal contradictions.     

二化螟成虫雄性先羽化现象

二化螟Chilos uppressalis(Walker)是水稻一种重要的鳞翅目害虫,作者在室内人工饲养的过程中注意到二化螟的雄虫羽化较雌虫早,因此对二化螟的雄性先熟现象进行了初步的研究,结果发现雌雄二化螟从初孵幼虫到成虫羽化阶段的历期平均长度存在显著差异,雄虫的历期为38.8d,而雌虫的历期为40.6d,即雄虫较雌虫要早1.8d羽化。本文对雄性先熟现象的生物学意义进行了简要讨论,同时,就利用性诱方法对二化螟进行监测和防治进行了讨论。