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... Despite the central role that female mate choice plays in the production of biological diversity, controversy remains concerning its evolution and maintenance. This is particularly true in systems where females are choosy but do not receive obvious direct benefits such as nuptial gifts that increase a female's survival and fecundity. In the absence of such direct benefits, indirect benefits (i.e., ...
... Selection should favor greater parental effort when the caring individual is more likely to be related to the offspring in its care. If certainty of paternity varies across broods, plasticity in the extent of paternal care may be advantageous, provided that cues of a male’s paternity are available. Consequently, to understand relationships between parentage and parental care, it is necessary to id ...
Microstigmus nigrophthalmus; altruism; brood rearing; females; males; nests; social behavior
Abstract:
... Altruism in the social Hymenoptera is generally considered to be a feature of females rather than males. A popular explanation for this is that in the solitary ancestors of today's social species, males provided little brood care. Males might therefore lack the preadaptations necessary to evolve altruism in social contexts. While anecdotal observations of male contributions to colony life have bee ...
... Natural enemies exert selection pressure on their prey. Predators and parasitoids drive their prey into the evolution of novel traits to cope with this stress. When eggs and juveniles are the target of enemies, defense strategies may rely on adults. However, it is not easy to predict whether adults should actively protect unrelated offspring. Females of the golden egg bug (Phyllomorpha laciniata) ...
oviposition; nests; reproductive performance; breeding; environmental factors; hatching; progeny; temperature; eggs; body condition; females; birds; Finland
Abstract:
... After laying the first egg, a bird can, to a certain extent, adjust the hatching date of the brood to environmental conditions. However, costs of this adjustment have remained largely unexplored. We studied potential costs of hatching delay in a population of blue tits in southern Finland. We explored the factors underlying hatching delay and investigated the association between hatching delay, cl ...
... In many taxa, parental strategies can vary among individuals. This is especially true in species with biparental care, with males, more often than females, deserting their mates. While there is an abundance of theoretical predictions and empirical data on factors inducing mate abandonment by males, much less is known about what consequences this may have on female behaviour, particularly in the fi ...
... Carotenoid-based ornaments (many yellow–orange–red colourations) may signal the genetic or parental quality of the bearer. Thus, their expression could influence the amount of resources/energy that the mate will invest in the production of offspring, thereby optimising its reproductive fitness. The differential allocation hypothesis (DAH) predicts that females mated with more attractive males shou ...
... Adolescence is the pivotal transitional phase during which animals become sexually and socially mature and acquire the skills to cope with a variety of environmental challenges on their own. We investigated in a bird species, the zebra finch, how the social environment experienced during this period influences their behaviour in a sexual context. Zebra finches were kept in pairs (male–female or ma ...
... When females mate with a heterospecific male, they do not usually produce viable offspring. Thus, there is a selective pressure for females to avoid interspecific mating. In many species, females innately avoid heterospecific males; females can also imprint on their parents to avoid later sexual interactions with heterospecific males. However, it was previously unknown whether adult females can le ...
... Division of labor in social groups can be influenced by differential nutrition. Consumption of more food or higher-quality food often affects individuals’ capacities for reproduction. In social insects, nutrients consumed during immature (e.g., larval) stages often affect adult reproductive capacity, but adult nutrition may also impact reproductive status. This study tested whether ovary developme ...
... Many species of teleost fish live in coral reefs and change sex depending on their social status; some even demonstrate sex change in both directions. Typically, in the absence of a more dominant competitive individual, the fish functions as a male; however, when a more competitively superior individual arrives, the focal fish becomes a female. Among these bidirectional sex changers, there are spe ...
... Senders and receivers influence dynamic characteristics of the signals used for mate attraction over different time scales. On a moment-to-moment basis, interactions among senders competing for a mate influence dynamic characteristics, whereas the preferences of receivers of the opposite gender exert an influence over evolutionary time. We observed and recorded the calling patterns of the bird-voi ...
... Animals adjust their antipredator behavior according to environmental variation in risk, and to account for their ability to respond to threats. Intrinsic factors that influence an animalâs ability to respond to predators (e.g., age, body condition) should explain variation in antipredator behavior. For example, a juvenile might allocate more time to vigilance than an adult because mortality as ...
... Intrinsic and environmental stressors, such as age and seasonality, may influence social behavior and endocrine levels in gregarious foragers, but little is known about how season and age affect both behavioral and physiological responses. We evaluated seasonal/age variation of aggression and vigilance, and seasonal/age variation of endocrine levels (fecal cortisol and testosterone metabolites), i ...
Anolis; adults; age structure; body size; breeding season; community structure; females; habitat preferences; interspecific variation; juveniles; landscapes; lizards; males; microhabitats; winter
Abstract:
... Animals should select microhabitats with features that enhance fitness. However, the fitness benefits of different habitats may vary across ages and between sexes. By quantifying microhabitat choice in relation to age or sex, as well as the specific fitness consequences of habitat selection, we can better understand the factors that shape the way organisms distribute themselves across landscapes. ...
... In mammalian polygynous mating systems, male reproductive effort consists mainly of male-male competition and courting of females, which entail substantial somatic costs. Males are thus expected to adjust their reproductive effort according to their age and condition. In this study, we examined how activity budgets of male mountain goats (Oreamnos americanus), a polygynous ungulate, varied with ag ...
... The structure of male mating signals is often influenced by age. The causes and consequences of age-based signal variation have been much studied in visual, acoustic, and chemical signaling modalities, but are less explored in species that use vibrational signals for mate attraction. However, the complex structure of many vibrational signals makes them ideal for investigating the relationships bet ...
Lycosidae; age structure; cannibalism; diet; females; males; mating behavior
Abstract:
... Female mating behaviors are known to be sensitive to a variety of individual factors both external and internal to a female; however, mating decisions are likely due to a suite of interacting factors. By independently manipulating female and male diet in the wolf spider Rabidosa rabida and testing females across age groups, we demonstrate that, in addition to its independent effect, female nutriti ...
Sula nebouxii; age structure; birds; elderly; females; longevity; males; nests; parental behavior; phenotype; progeny; social behavior
Abstract:
... In long-lived species, behaviour is expected to vary across the lifespan, first improving with maturation and experience and then declining with senescence, but measurement is rare, particularly during old age. Measuring nest defence intensity in 255 known-age blue-footed boobies (Sula nebouxii) of 19 age classes confirmed the inverted-U pattern: intensity of nest defence increased in young males ...
... Female birds can influence offspring development by adjusting egg size or by a differential allocation of egg resources. Such maternal effects can be expected to be shaped by natural selection, given the costs connected to the allocation of maternal resources. Among egg components, yolk androgens play an important role in affecting offspring life-history traits. Despite their relevance for nestlin ...