Abstract In iteroparous species high investment in current reproduction is usually paid terms of reduced future and increased mortality. However, the proximal mechanisms these costs remain poorly understood. Free radicals arising as by‐products normal metabolic activities have deleterious effects on cellular proteins, lipids DNA, this phenomenon known oxidative stress. Since an energetically demanding activity, which increases both basal field rates, one could expect that breeding effort...

Carotenoid-based sexual traits are thought to be reliable indicators of male quality because they might scarce and therefore indicate the ability males gather high-quality food involved in important physiological functions (as immune enhancers antioxidants). We performed an experiment where female zebra finches (Taeniopygia guttata) were provided with increasing carotenoid doses drinking water during 4 weeks (bill color this species is a carotenoid-based signal). Simultaneously, birds split...

Major life history traits, such as fecundity and survival, have been consistently demonstrated to covary positively in nature, some individuals having more resources than others allocate all aspects of their history. Yet, little is known about which (or state variables) may account for covariation. Reactive oxygen species (ROS) are natural by‐products metabolism and, when ROS production exceeds antioxidant defenses, organisms exposed oxidative stress that can deleterious effects on survival....

Optimal investment into life‐history traits depends on the environmental conditions that organisms are likely to experience during their life. Evolutionary theory tells us optimal in reproduction versus maintenance is shape pattern of age‐associated decline performance, also known as aging. The currency traded against different vital functions is, however, still debated. Here, we took advantage a phenotypic manipulation individual quality early life explore (1) long‐term consequences...

Early nutrition has recently been shown to have pervasive, downstream effects on adult life–history parameters including lifespan, but the underlying mechanisms remain poorly understood. Damage biomolecules caused by oxidants, such as free radicals generated during metabolic processes, is widely recognized a key contributor somatic degeneration and rate of ageing. Lipophilic antioxidants (carotenoids, vitamins A E) are an important component vertebrate defences against damage. By using avian...

1 Sex differences in levels of parasite infection are a common rule wide range mammals, with males usually more susceptible than females. Sex-specific exposure to parasites, e.g. mediated through distinct modes social aggregation between and within genders, as well negative relationships androgen immune defences thought play major role this pattern. 2 Reproductive female bats live close association clusters at maternity roosts, whereas nonbreeding females generally occupy solitary roosts....

Parental effort is usually associated with high metabolism that could lead to an increase in the production of reactive oxidative species giving rise stress. Since many antioxidants involved resistance stress can also enhance immune function, parental may diminish level otherwise parasite resistance. In present study, we performed brood size manipulation a population great tits ( Parus major ) create different levels effort. We measured and used newly developed quantitative PCR assay...

Within-host microbial communities and interactions among microbes are increasingly recognized as important factors influencing host health pathogen transmission. The community associated with a is indeed influenced by complex network of direct indirect between the lineages it harbors, but mechanisms rarely established. We investigated within-host strains Borrelia burgdorferi, causative agent Lyme disease, using experimental infections in mice. used fully crossed-design three distinct...

Parasites are often aggregated on a minority of the individuals in their host populations. Although characteristics commonly presumed to explain parasite aggregation hosts, spatio-temporal parasites during host-seeking stages may have dominant effect hosts. We aimed quantify, using mixed models, repeatability and autocorrelation analyses, degree which blacklegged ticks (Ixodes scapularis) white-footed mice (Peromyscus leucopus) is influenced by distributions heterogeneity among mice....

Coinfections with parasitic helminths and microparasites are highly common in nature can lead to complex within-host interactions between parasite species which cause negative health outcomes for humans, domestic wild animals. Many of these effects worsen increasing burdens. However, even though many studies have identified several key factors that determine worm burdens across various host systems, less is known about how the immune response interacts what consequences outcome interactions....

Many parasites infect multiple sympatric host species, and there is a general assumption that parasite transmission between co-occurring species commonplace. Such between-species could be key to persistence within disease reservoir consequently an emerging focus for control. However, while growing body of theory indicates the potential importance persistence, conclusive empirical evidence from natural communities lacking, inevitable may therefore wrong. We investigated occurrence in...

Abiotic factors including thermal stress are suggested to exert constrains on sexual ornaments through trade-offs between displays and physiological functions related self-maintenance. Given the health properties of carotenoid pigments, carotenoid-based offer a relevant context in which investigate effect environmental stress, such as ambient temperature, production maintenance secondary traits and, also, explore proximate mechanisms shaping their expression. In this study, we exposed male...

1 Parasites use resources from their hosts, which can indirectly affect a number of host functions because trade-offs in resource allocation. In order to get comprehensive view the costs imposed by blood sucking parasites it is important monitor multiple components development and physiology parasitized hosts over long time periods. 2 The effect infestation fleas on body mass, length growth, haematocrit, resistance oxidative stress, resting metabolic rate humoral immune response were...

Vaccinating wildlife is becoming an increasingly popular method to reduce human disease risks from pathogens such as Borrelia burgdorferi, the causative agent of Lyme disease. To successfully limit risk, vaccines targeting reservoirs B. burgdorferi must be easily distributable and effectively pathogen transmission infected animals, given that many animals in nature will prior vaccination. We assessed efficacy oral bait vaccine based on immunogenic outer surface protein A (OspA) protect...

SUMMARY Parasitism is often a source of variation in host's fitness components. Understanding and estimating its relative importance for components hosts fundamental from physiological, ecological evolutionary perspectives. Host-parasite studies have reported parasite-induced reduction host fecundity, whereas the effect parasitism on survival has been largely neglected. Here, we experimentally investigated infestation by rat fleas ( Nosopsyllus fasciatus ) life span wild-derived male common...

Summary 1. Harsh environmental conditions experienced during development can reduce the performance of same individuals in adulthood. However, ‘predictive adaptive response’ hypothesis postulates that if adapt their phenotype to environments where they are likely live future, exposed harsh early life perform better when encountering adulthood compared those never these before. 2. Using common vole ( Microtus arvalis ) as study organism, we tested how exposure flea parasitism juvenile stage...

Optimal investment into life-history traits depends on the environmental conditions that organisms are likely to experience during their life. Evolutionary theory tells us optimal in reproduction versus maintenance is shape pattern of age-associated decline performance, also known as aging. The currency traded against different vital functions is, however, still debated. Here, we took advantage a phenotypic manipulation individual quality early life explore (1) long-term consequences...

Investment of resources in immune defences, despite obvious short-term benefits, may be detrimental to long-term maintenance and thus decrease longevity absence parasites. In addition, females males differ investment intrinsic because they are subjected different degrees sexual competition extrinsic mortality. order test if sex-specific mounting an response reduced longevity, we compared the captive male female common voles Microtus arvalis regularly challenged with keyhole limpet...

Vector-borne pathogens, many of which cause major suffering worldwide, often circulate in diverse wildlife communities comprising multiple reservoir host and/or vector species. However, the complexities these systems make it challenging to determine contributions different species transmission. We experimentally manipulated transmission within a natural multihost–multipathogen–multivector system, by blocking flea-borne pathogen from either two co-occurring (bank voles and wood mice). Through...