Effects of bot fly, Cuterebra fontinella, parasitism on male aggression and female choice in Peromyscus leucopus (original) (raw)
Related papers
Bot flies are common parasites of Peromyscus leucopus, although determination of a cost to the host has been elusive. The goal of this study was to further explore the potential costs of bot fly parasites for a population of P. leucopus. We investigated the effects of parasitism on host condition (mass after controlling for parasite mass and host body length) and survivorship (the number of days animals persisted on trapping grids). Parasitism was quantified by prevalence (proportion of the population infected), intensity (the number of parasites per infected host), and dispersion of parasites within hosts (clumped, regular, or random). In addition, we searched for spatial and temporal patterns in infection. Finally, we analyzed the relationship between population demography and parasitism. Contrary to expectations, we found that infected mice persisted longer on trapping grids and were in better condition than uninfected mice. Also, we discovered that when considering overall infection levels, parasites were clumped within hosts, but when considering the number of simultaneous infections, parasites were randomly distributed among hosts. Although most animals had single infections, there was a high incidence of reinfections, leading to bimodal patterns of parasitism. Prevalence was not correlated with host density, sex ratio, or proportion reproductive, but there were significant relationships between intensity and density and sex ratio in 1 year. In addition, prevalence and proportion of reproductively active animals were asynchronous. These results suggest that bot flies do not impose an obvious cost to their hosts, and hosts may express some degree of tolerance for bot fly parasitism.
A PRESCRIPTION FOR LONGER LIFE? BOT FLY PARASITISM OF THE WHITE-FOOTED MOUSE
Ecology, 2005
Investigation of host-parasite interactions typically reveals a negative impact of parasitism on the host species. In contrast, mounting evidence indicates that bot fly (Cuterebra sp.) infestation enhances the survival of white-footed mice (Peromyscus leucopus). We propose that life history trade-offs, namely, between reproduction and survival, can explain this counterintuitive observation. By using an extensive data set spanning a decade, 12 sites in two states, and over 30 000 mouse captures, we offer a new perspective on the effects of bot fly parasitism on white-footed mice. Analysis of persistence time corroborated earlier studies that showed significantly higher survival rates of infested mice. Although a higher proportion of infested than uninfested females were in breeding condition, secondary reproductive success appeared to be negatively impacted by parasitism via declines in the number of litters and the total number of offspring produced by infested females. Population growth rates were negatively correlated with infestation prevalence, further indicating a negative effect of parasitism. Based on the negative impact of parasitism on reproduction, we propose that enhanced survival of infested mice can be explained by the diversion of resources from reproduction to body maintenance. Parasite-induced life history shifts in which mice decrease current reproduction to promote future reproduction, such as increasing the age at maturity, may also contribute to the decline in population growth rate observed in years of high infestation prevalence.
Does Host Value Influence Female Aggressiveness, Contest Outcome and Fitness Gain in Parasitoids?
Ethology, 2007
Intraspecific competition for resources is common in animals and may lead to physical contests. Contest outcomes and aggressiveness can be influenced by the resource holding potential of contestants but also by their perception of the resource value (RV). Competitors may assess resource quality directly (real RV) but may also estimate it according to their physiological status and their experience of the habitat quality (subjective RV). In this article, we studied contests between females of the solitary parasitoid Pachycrepoideus vindemmiae Rondani (Hymenoptera: Pteromalidae) when exploiting simultaneously a host, a Delia radicum L. (Diptera: Anthomyiidae) pupa. We tested the effect of factors modifying host value on the occurrence of agonistic behaviours, contest outcomes and host exploitation. The factors tested were: the quality of the previous habitat experienced by females, female egg load, host parasitism status and the stage reached by the owner female in her behavioural oviposition sequence. Females successfully protected their host against intruders during its exploitation, but not after oviposition, and their aggressiveness did not seem to be influenced by their perception of the RV. The fact that the host is subsequently parasitized by the opponent females appears to mainly depend on the host selectiveness of females.
Infestation of Rock Mice (Peromyscus difficilis) by Botflies: Ecological Consequences of Differences Between Sexes., 1997
I tested the hypothesis that infestation by botflies (Cuterebra) is male-biased and related to increased movement in the rock mouse (Peromyscus difficUis) during 2 full-annual cycles. During both years, adult females were more heavily infested in autumn, but adult males were more heavily infested in winter. Rates of infestation were negatively related to movements of animals. Females had higher infestation in the breeding season when they move less, whereas males had higher infestation in the non-breeding season. In grids with supplemental feod, higher rates of infestation occurred among individuals, especially females, that used traps near food stations.
Parasite-Mediated Mate Preferences in a Cooperatively Breeding Rodent
Frontiers in Ecology and Evolution
Females of many species discriminate among males when choosing a mate and this can bear indirect and direct benefits including the avoidance of parasite transmission from infested males. In rodents, this may be mediated by androgen hormones that affect the expression of urinary odors. Female choosiness may also vary with a female’s infestation status, with infested females being less choosy. In the current study we tested the preference of cooperatively breeding highveld mole-rat (Cryptomys hottentotus hottentotus) females for male urinary odors from healthy males and those naturally infested with a cestode (Mathevotaenia sp.). Thirty females (15 healthy, 15 infested) were allowed to explore a Y-maze with urine samples from healthy and infested males and the frequency of entering choice arms and chambers as well as the duration spend with each odor sample was recorded. Infestation status did neither affect male body mass, urinary testosterone, nor cortisol levels or the body conditi...
Journal of mammalogy, 1997
I tested the hypothesis that infestation by botflies (Cuterebra) is male-biased and related to increased movement in the rock mouse (Peromyscus difficUis) during 2 full-annual cycles. During both years, adult females were more heavily infested in autumn, but adult males were more heavily infested in winter. Rates of infestation were negatively related to movements of animals. Females had higher infestation in the breeding season when they move less, whereas males had higher infestation in the non-breeding season. In grids with supplemental feod, higher rates of infestation occurred among individuals, especially females, that used traps near food stations.
Physiological Entomology, 2015
Previous work has shown that male flesh flies (Sarcophaga crassipalpis Macquart) exhibit an ontogeny of behaviour from eclosion through sexual maturity that includes extensive changes in the expression of aggressive, non-aggressive interactive and non-interactive behaviours. To determine how the presence of a female flesh fly influences the manifestation of these behaviours, male flesh flies of different ages post-eclosion are paired with same-age females and their behaviours are monitored in a simple arena during a 50-min observation period. All flies are socially isolated until pairing. Although the levels of expression of aggressive and non-aggressive interactive behaviours are depressed relative to previous findings in male-opponent pairs, the ontogeny of aggression still occurs as indicated by a significant increase, with age, in the agonistic behaviour 'hold'. Similar to male-opponent pairs and individual males, the performance by males of the non-interactive behaviours 'walking' and 'standing' diminishes, whereas 'upside-down' increases with age. By contrast, 'grooming' shows a significant age-related decline. No courtship behaviours are observed in the males, although the aggressive behaviour 'hold' is a significant transition to mating. Females show no obvious courtship or rejection behaviours, although the significant increase in 'upside-down' with age could possibly be a behavioural gateway to mating. The results of this study indicate that extensive age-related changes encompassing the entire behavioural repertoire are intrinsic to male flesh flies and persist under a variety of different social contexts.
Animal Behaviour, 2017
Animal behaviours, like aggression, can directly impact host health by influencing exposure to parasites. Aggressive individuals may experience an increase in agonistic interactions and contact rates with conspecifics, which might increase their probability of acquiring parasites. However, aggression is not the only factor that shapes parasitism; proximate mechanisms like hormone-modulated immunosuppression can also have broad impacts. Here, we hypothesize that high levels of aggression, cortisol (C), and testosterone (T) will be positively associated with parasitism, and that aggressive individuals will play a larger role spreading parasites to conspecifics than docile individuals. Aggression was measured using the level of aggressive response to human handling during capture. The aim of this study was to examine associations between aggression and hormones, C and T, on variation in endo-and ecto-parasitism in a population of wild mouse lemurs (Microcebus rufus) over a three-year period. By tracking the movement of lice (directly transmitted parasites) in the population, we also examined the effect of host aggression on population-wide parasite dynamics. We show that animals with high T and C were more likely to exhibit aggressive behaviors, and C was associated with significantly higher ectoparasite infestations. Aggressive individuals were significantly more infested by lice, and also donated significantly more lice to conspecifics in the population. Taken together, our results offer insight into the individual and population health costs of aggression, and empirical support of a trade-off between aggression and ectoparasitism, which may have driven the evolution of aggression and interactions with conspecifics.
Physiological Entomology, 2015
Previous work has shown that male flesh flies (Sarcophaga crassipalpis Macquart) exhibit an ontogeny of behaviour from eclosion through sexual maturity that includes extensive changes in the expression of aggressive, non-aggressive interactive and non-interactive behaviours. To determine how the presence of a female flesh fly influences the manifestation of these behaviours, male flesh flies of different ages post-eclosion are paired with same-age females and their behaviours are monitored in a simple arena during a 50-min observation period. All flies are socially isolated until pairing. Although the levels of expression of aggressive and non-aggressive interactive behaviours are depressed relative to previous findings in male-opponent pairs, the ontogeny of aggression still occurs as indicated by a significant increase, with age, in the agonistic behaviour 'hold'. Similar to male-opponent pairs and individual males, the performance by males of the non-interactive behaviours 'walking' and 'standing' diminishes, whereas 'upside-down' increases with age. By contrast, 'grooming' shows a significant age-related decline. No courtship behaviours are observed in the males, although the aggressive behaviour 'hold' is a significant transition to mating. Females show no obvious courtship or rejection behaviours, although the significant increase in 'upside-down' with age could possibly be a behavioural gateway to mating. The results of this study indicate that extensive age-related changes encompassing the entire behavioural repertoire are intrinsic to male flesh flies and persist under a variety of different social contexts.