Abstract In socially monogamous species, males that risk cuckoldry more than others might gain inclusive fitness by yielding paternity to relatives. We tested this prediction in the Tibetan ground tit Pseudopodoces humilis , an unusual facultative cooperative breeder wherein most helpers (87% males) join a mated pair shortly before clutch completion. Extra‐pair among bi‐parental broods occurred less often (26% of broods, 9% young) compared with (68%, 25%). former, extra‐pair sires (88%) were...

In avian cooperative breeding systems, many benefits obtained by social pairs from the presence of helpers have been uncovered. However, until now, factors that determine type assistance provide and responses not well illustrated. We examined contribution to groups relevant dominant in azure‐winged magpie Cyanapica cyana which breeds on Tibetan Plateau. used capture–mark–recapture method identify helpers. Results showed were mostly yearling sons pairs. They mainly contributed group three...

Songbirds in seasonal environments often adjust their breeding strategy according to spatial or temporal changes conditions. Here we investigate how horned larks Eremophila alpestris , a multi‐brooded songbird on the Tibetan Plateau, responded changing risk of nest predation and food availability across attempts. We showed that both concealment supply increased with plant growth, adjusted strategies accordingly. First they selected nest‐sites where predator density was low, which enhanced...

Reproductive skew models predict how animal groups containing multiple males maintain stable through partitioning reproduction. However, these have rarely been tested in vertebrates, especially birds where tests made for less than 10 of more 800 species that regularly exhibit cooperative breeding behavior. In the ground tit Parus humilis, a group consists primary pair members and secondary individuals are mainly failed male breeders. A previous study showed low quality thus facing high...

It is common in birds that the sizes of nestlings vary greatly when multiple young are produced one nest. However, methods used by parents to establish size hierarchy among and their effect on parental provisioning pattern may differ between species. In Azure‐winged Magpie Cyanopica cyanus , we explored how why controlled nestlings. Asynchronous hatching was main cause within brood, although laying larger eggs later sequence reduced this effect. Parents with asynchronous broods more fledged...

Altricial birds show enormous intraspecific diversity in their provisioning strategies, terms of both the rate and amount food delivered per feeding bout. Extra‐pair copulations (EPCs), which result either extra‐pair paternity (EPP) or maternity (EPM), provide an opportunity to demonstrate why strategies vary among individuals. Because EPP‐cuckolded males EPM‐cuckolded females must raise unrelated young, whereas need not, we hypothesized that first two categories breeders would reduce...

Extrapair fertilizations (EPFs) occur widely in socially monogamous birds and result mixed parentage the brood. The response of an individual to these EPFs its social mate remains poorly investigated terms parental care for We addressed this question a cooperatively‐breeding corvid, azure‐winged magpie Cyanopica cyana . Parentage analysis indicated that 45% females 37% males engaged EPFs. There were 49% cooperative groups 36% bi‐parental nests with extrapair paternity (EPP) offspring, 22%...

Life-history theory assumes that selection favors parents can maximize their reproductive success via behavioral strategies. As brood size determines the value of each nestling, may adjust food-allocation patterns according to size. We test this assumption in Horned Lark (Eremophila alpestris (L., 1758)). Our findings revealed nestling begging forms varied with size, by gaping one-chick broods and postural activity two- three-chick broods. Accordingly, parental differed different-sized In...

Parent birds show a continuous spectrum of breeding strategies, ranging from low‐fecundity and high‐survival pattern to high‐fecundity, low‐survival pattern. Investigations parental strategies under variable environmental conditions can illustrate how parents trade‐off the benefits costs these two extreme strategies. White‐collared Blackbirds Turdus albocinctus breed twice year on Tibetan Plateau. We that both life‐history traits feeding behaviour differ between attempts. In first attempt,...

Life‐history theory predicts that parents refer to the resources they hold determine their breeding strategy. In multi‐brooded species, it is hypothesized single‐brooded produce larger clutches and raise offspring with a brood survival strategy, whereas only do this under good conditions. Under poor conditions, smaller reduction We tested hypothesis in Brown‐cheeked Laughing Thrush Trochalopteron henrici , which can breed twice year on Tibetan Plateau, by investigating life‐history traits...

Abstract Background Great diversity exists in the parenting pattern of altricial birds, which has long been considered as an adaptive response to specific environmental conditions but not their life-history style. Methods We examined egg-laying and nestling-raising Grey-backed Shrike ( Lanius tephronotus ) that breeds only once a year on Tibetan Plateau. compared dietary composition its sympatric competitor, Brown-cheeked Laughing Thrush Trochalopteron henrici twice year. Results Female...

Abstract Territoriality is an important male behavioral trait used in mate selection of butterflies, but the factors determining outcome territorial contests remain controversial. We studied foraging and behaviors males Parnassius imperator butterfly. Adult were selective about nectar sources, they did not defend flowers. By contrast, fought over areas bare rocks because as lek locations to attract court receptive females. The ownership a lek, rather than sex pheromones or wing pigments,...

Abstract Theory predicts that because males are more variable in reproductive success than females, a mother should produce sons to maximize fitness return from the sex allocation if she is of high-quality (the female quality hypothesis) or mates with male hypothesis). While most previous studies have looked at each hypothesis, we tested both them simultaneously white-rumped snowfinch Montifringilla taczanowskii, socially monogamous, sexually monomorphic passerine where body size potential...

In many species, nestling demands vary continuously during early development and both parents have different parental care strategies at each age. Sexual conflict arises when parent expects its partner investing more in care. It is largely unknown how the two respond to dynamics of resolve sexual period, especially on Qinghai-Tibetan Plateau. To address this question, we monitored behaviors horned larks (Eremophila alpestris) using video-recording systems. We found that male invested less...

Abstract Phenotypic plasticity, which encompasses the diversification of both irreversible and reversible traits, has long been considered an adaptive response by animals to varying environmental conditions. However, process traits are coordinated form changing environment yet be clarified. Here, we investigated variation in body size two urban insect species context habitat fragmentation. These were Chinese cricket Gryllus chinensis stove grasshopper Diestrammena japonica , sympatric...

In social animals, when conspecific individuals use limited resources differently jealousy will occur. To address whether is an environmental variable underlying negative evolutionary responses to superior phenotypes, we investigated jealous behaviours in the azure-winged magpie, Cyanopica cyanus, under natural and experimental conditions. Within a triad composed of feeder, target three differently-ranked third-party individuals, was fed exclusively experimentally imitate scene uneven...

Avian reproductive strategies exhibit remarkable plasticity in various scenarios, posing challenges determining the optimal pathway through which parents enhance their success. we addressed this question by employing structural equation modeling (SEM) analysis a long-term field survey for azure-winged magpie (Cyanopica cyanus), had accumulated datasets multiple components, including extra-pair fertilization (EPF), hatching failure, nest predation predators and conspecific raiders, offspring...