Brooding is a major breeding investment of parental birds during the early nestling stage, and has important effects on the development and survival of nestlings. Investigating brooding behavior can help to understand...Brooding is a major breeding investment of parental birds during the early nestling stage, and has important effects on the development and survival of nestlings. Investigating brooding behavior can help to understand avian breeding investment strategies. From January to June in 2013 and 2014, we studied the brooding behaviors of long-tailed tits （Aegithalos caudatus glaucogularis） in Dongzhai National Nature Reserve, Henan Province, China. We analyzed the relationships between parental diurnal brooding duration and nestling age, brood size, temperature, relative breeding season, time of day and nestling frequencies during brooding duration. Results showed that female and male long-tailed tit parents had different breeding investment strategies during the early nestling stage. Female parents bore most of the brooding investment, while male parents performed most of the nestling feedings. In addition, helpers were not found to brood nestlings at the two cooperative breeding nests. Parental brooding duration was significantly associated with the food delivered to nestlings （F=86.10, dr=l, 193.94, P〈0.001）, and was longer when the nestlings received more food. We found that parental brooding duration declined significantly as nestlings aged （F=5.99, dr=-1, 50.13, P=0.018）. When nestlings were six days old, daytime parental brooding almost ceased, implying that long- tailed tit nestlings might be able to maintain their own body temperature by this age. In addition, brooding duration was affected by both brood size （F=12.74, dr=-1,32.08, P=0.001） and temperature （F=5.83, df=-l, 39.59, P=-0.021）, with it being shorter in larger broods and when ambient temperature was higher.展开更多
In this study,we report an unusual homing behavior of the Sichuan Partridge(Arborophila rufipectus)at the Laojunshan National Nature Reserve,Sichuan Province,China.Hen Sichuan Partridges led the chicks back to the nes...In this study,we report an unusual homing behavior of the Sichuan Partridge(Arborophila rufipectus)at the Laojunshan National Nature Reserve,Sichuan Province,China.Hen Sichuan Partridges led the chicks back to the nests where they hatched in the evening and roosted there over night.This behavior lasted 6.7±4.3 nights(range=1–15;n=13)after the chicks hatched.At this stage,the hens became very vigilant to predators and human disturbance.If disturbed,they often abandoned the nests immediately and no longer returned thereafter.The ambient temperature at night during the early brooding period of Sichuan Partridge at our study site was^12.4°C.Our findings suggest that hen Sichuan Partridges may make trade-offs between nest predation risks versus the thermoregulatory needs of their young.展开更多
The key techniques of artificial incubation and brooding of Bonasa bonasia during breeding technology promotion was summed up in the paper.Electric incubation and dielectric incubation,electric brooding and dielectric...The key techniques of artificial incubation and brooding of Bonasa bonasia during breeding technology promotion was summed up in the paper.Electric incubation and dielectric incubation,electric brooding and dielectric brooding were compared with each other.The results showed that the effect of dielectric inoculation was poor,and there were no significant difference between electric brooding and dielectric brooding.展开更多
Urban areas differ from natural habitats in several environmental features that influence the characteristics of animals living there.For example,birds often start breeding seasonally earlier and fledge fewer offsprin...Urban areas differ from natural habitats in several environmental features that influence the characteristics of animals living there.For example,birds often start breeding seasonally earlier and fledge fewer offspring per brood in cities than in natural habitats.However,longer breeding seasons in cities may increase the frequency of double-brooding in urban compared with nonurban populations,thus potentially increasing urban birds’annual reproductive output and resulting in lower habitat difference in reproductive success than estimated by studies focusing on first clutches only.In this study,we investigated 2 urban and 2 forests great tit Parus major populations from 2013 to 2019.We compared the probability of double-brooding and the total number of annually fledged chicks per female between urban and forest habitats,while controlling for the effects of potentially confounding variables.There was a trend for a higher probability of double-brooding in urban(44%of females)than in forest populations(36%),although this was not consistent between the 2 urban sites.Females produced significantly fewer fledglings annually in the cities than in the forest sites,and this difference was present both within single-and double-brooded females.Furthermore,double-brooded urban females produced a similar number of fledglings per season as single-brooded forest females.These results indicate that double-brooding increases the reproductive success of female great tits in both habitats,but urban females cannot effectively compensate in this way for their lower reproductive output per brood.However,other mechanisms like increased post-fledging survival can mitigate habitat differences in reproductive success.展开更多
Dear Editor,Coral reefs sustain high biodiversity and have been referred to as the rainforests of the ocean.However,anthropogenic stressors have led to a global decline of coral reefs,partly due to the increasing scal...Dear Editor,Coral reefs sustain high biodiversity and have been referred to as the rainforests of the ocean.However,anthropogenic stressors have led to a global decline of coral reefs,partly due to the increasing scale,frequency,and intensity of coral bleaching events driven by global warming(Henley et al.,2024;Hughes et al.,2018).展开更多
The brood-parasitic brown-headed cowbird(Molothrus ater)has one of the shortest incubation periods of any bird.Brown-headed cowbird eggs,and those of other avian brood parasites,tend to be more spherical due to their ...The brood-parasitic brown-headed cowbird(Molothrus ater)has one of the shortest incubation periods of any bird.Brown-headed cowbird eggs,and those of other avian brood parasites,tend to be more spherical due to their greater relative width.The traditional explanation for this egg shape is that it,combined with the thicker eggshells,resists host puncture-ejection.However,very few North American hosts of the brownheaded cowbird actually engage in puncture-ejection and therefore wider eggs may instead provide greater contact with a host’s brood patch during incubation,especially in large host nests.We tested whether greater egg width increased mean temperature and reduced temperature variation in brown-headed cowbirds by inserting temperature probes into brown-headed cowbird and house sparrow(Passer domesticus)eggs and placing them into red-winged blackbird(Agelaius phoeniceus)nests.House sparrow eggs are similar in appearance and in length to cowbird eggs,but are not as wide.We found no signifcant relationship between brown-headed cowbird egg width and mean incubation temperature.However,brown-headed cowbird eggs experienced less temperature variation than house sparrow eggs,and within brown-headed cowbird eggs,more spherical eggs experienced less temperature variation when accounting for differences in width.These results suggest that brownheaded cowbirds may have short incubation periods in part because their eggs exhibit less temperature variation over the course of incubation.The brown-headed cowbird’s egg shape may contribute to its accelerated embryonic development rate relative to host eggs of similar size,which explains its ability to hatch in a variety of host nests.展开更多
With the ongoing acceleration of global urbanization, an increasingly larger proportion of natural habitats are being transformed and utilized by humans. Urbanization has a substantial impact on animal populations, ex...With the ongoing acceleration of global urbanization, an increasingly larger proportion of natural habitats are being transformed and utilized by humans. Urbanization has a substantial impact on animal populations, exposing them to greater risks, but also presenting new opportunities and resources. Although the effects of urbanization and brood parasitism on the population dynamics and behavior of host birds have received considerable attention, there has been comparatively little research on how urbanization might affect the risk of brood parasitism on host birds. From April to August in 2023 and 2024, we investigated the risk of brood parasitism on Azure-winged Magpies (Cyanopica cyanus) breeding in the urban center, outskirt, and rural areas of Wuhan City, Hubei Province, China. The results revealed significant differences in the risk of brood parasitism among Azure-winged Magpies in the three regions, with the proportion of magpies parasitized by the Asian Koel (Eudynamys scolopaceus) being found to be significantly lower in the city center (0%) than that in outskirt (3.8%) and rural (11.4%) areas. Our results are consistent with the idea that cities can act as refuges that reduce the risk of brood parasitism experienced by host Azure-winged Magpies. Accordingly, breeding in cities enables Azure-winged Magpies to escape brood parasitism by the Asian Koel.展开更多
Avian brood parasitism is a unique reproductive behavior in which parasitic birds depend on other species to incubate their eggs and raise their offspring.In China,there are 20 species of cuckoos in the family Cuculid...Avian brood parasitism is a unique reproductive behavior in which parasitic birds depend on other species to incubate their eggs and raise their offspring.In China,there are 20 species of cuckoos in the family Cuculidae,order Cuculiformes,of which 17 species are parasitic cuckoos.This makes China one of the countries with the largest number of parasitic cuckoo species worldwide.Understanding the host utilization of cuckoos provides fundamental data for studying the coevolution of cuckoos with their hosts.We collected information on cuckoo hosts from the literature,photographs provided by birdwatchers,and online short video platforms,combined these data with our field observations,and summarized the parasitic cuckoos and their host species in China.A total of 1155 parasitism events were counted,involving 12 parasitic cuckoo species and 87 bird host species.These hosts belonged to 26 families,among which Muscicapidae was the most diverse with 19 species,accounting for 21.8%of the total hosts,followed by the families Phylloscopidae and Leiothrichidae with 8 species each,accounting for 9.2%of the total hosts recorded.The Common Cuckoo(Cuculus canorus)had the largest number of host taxa with 38 species,accounting for 43.7%of the total host species.This study adds 14 host species that have not been reported in China.However,for five species,the Jacobin Cuckoo(Clamator jacobinus),Banded Bay Cuckoo(Cacomantis sonneratii),Violet Cuckoo(Chrysococcyx xanthorhynchus),Common Hawkcuckoo(Hierococcyx varius),and Whistling Hawk-cuckoo(Hierococcyx nisicolor),information regarding host utilization is still lacking.展开更多
Alarm calls in bird vocalizations serve as acoustic signals announcing danger.Owing to the convergent evolution of alarm calls,some bird species can beneft from eavesdropping on certain parameters of alarm calls of ot...Alarm calls in bird vocalizations serve as acoustic signals announcing danger.Owing to the convergent evolution of alarm calls,some bird species can beneft from eavesdropping on certain parameters of alarm calls of other species.Vocal mimicry,displayed by many bird species,aids defense against predators and may help brood parasites during parasitism.In the coevolutionary dynamics between brood parasites,such as the common cuckoo(Cuculus canorus),and their hosts,female cuckoo vocalizations can induce hosts to leave the nest,increasing the probability of successful parasitism and reducing the risk of host attacks.Such cuckoo calls were thought to mimic those of the sparrowhawk.However,owing to their similarity to alarm calls,we propose a new hypothesis:Female cuckoos cheat their hosts by mimicking the parameters of the host alarm call.In this study,we tested this new hypothesis and the sparrowhawk mimicry hypothesis simultaneously by manipulating the syllable rate in male and female common cuckoo vocalizations and playing them in front of the host Oriental reed warbler(Acrocephalus orientalis)for examination.The results indicate that similar to a normal female cuckoo call,a female call with a reduced syllable rate prompted the hosts to leave their nests more frequently and rapidly than male cuckoo calls.Additionally,the male cuckoo calls with increased syllable rate did not prompt the host to leave their nests more frequently or quickly compared with the male cuckoo calls with a normal syllable rate.Our results further confrm that female common cuckoos mimic the vocalizations of Eurasian sparrowhawks(Accipiter nisus),reveal the function mechanisms underlying such mimicry,and support the theory of imperfect mimicry.展开更多
For songbirds,the post-fledging period is critical for development and survival,as young must learn to get food,practice flying,and identify predators to become independent from their parents and disperse or migrate.O...For songbirds,the post-fledging period is critical for development and survival,as young must learn to get food,practice flying,and identify predators to become independent from their parents and disperse or migrate.Obligate avian brood parasites,like cuckoos and cowbirds,lay eggs in nests of other bird species that provide parental care until the parasite’s young become independent.The information on the post-fledging period in songbirds is limited due to the difficulty in following and observing fledglings and it is even scarcer for brood parasites.We studied the behavior,survival,and age of independence of Shiny Cowbird(Molothrus bonariensis)fledglings raised by 2 hosts that differ markedly in body size:the House Wren(Troglodytes aedon)and the Chalk-Browed Mockingbird(Mimus saturninus).We radio-tracked individuals from a few days before they left the nest until they disappeared from the natal territory.We found:(1)chicks left the nest when they were 11-15 days of age and the age of fledgling did not differ between the 2 host species,(2)after leaving the nest,they spent most of the time perched in a hidden place without begging but as they grew,the proportion of time perched without begging decreased and begging in hidden and exposed places increased,(3)we observed approaches between adult parasitic females and young in host territories,(4)young abandoned the host territory and joined conspecific flocks when they were 35-39 days of age,and(5)the estimated post-fledging survival was between 12.5%and 20.8%.展开更多
In this exposé we provide the first review of host use by brood parasitic cuckoos in a multiple-cuckoo system in China, based on our own long-term field data and a compilation of observations obtained from the li...In this exposé we provide the first review of host use by brood parasitic cuckoos in a multiple-cuckoo system in China, based on our own long-term field data and a compilation of observations obtained from the literature. In total, we found that 11 species of cuckoos utilized altogether 55 host species. These hosts belong to 15 families, in which Sylviidae, Turdidae and Timaliidae account for 22.6%, 20.8% and 17.0% of parasitism records, respectively. The Common Cuckoo (Cuculus canorus) had the widest range of host species, accounting for 45.5% of the total number of parasitized species (25 in 10 families) of all parasitism records and is the most frequent brood parasite in the country. Cuckoo species differed in their egg coloration and the extent of egg polymorphism with most of them, e.g. the Common Cuckoo, the Lesser Cuckoo (C. poliocephalus) and the Plaintive Cuckoo (Cacomantis merulinus) laying well mimetic eggs with respect to their hosts based on human being’s visual observations, while others such as the Large Hawk-cuckoo (C. sparverioides), the Himalayan Cuckoo (C. saturatus) and the Asian Emerald Cuckoo (Chrysococcyx maculatus) usually laid non-mimetic eggs. The use of cuckoo hosts and egg color variation in China are compared with those in other parts of their ranges in Asia.展开更多
Genetic variations of three species from primary parent （OI Q,SIS Q,Kona Bay Q） and their first filial generation （OI Z,SIS Z,Kona Bay Z） of Litopenaeus vannamei were detected using microsatellite marker technique...Genetic variations of three species from primary parent （OI Q,SIS Q,Kona Bay Q） and their first filial generation （OI Z,SIS Z,Kona Bay Z） of Litopenaeus vannamei were detected using microsatellite marker technique.The amplified products of genomic DNA with 8 microsatellite makers indicated that 8 loci presents polymorphism,the number of total alleles were 28 in 6 species;the number of allele of every loci was 2 to 6;mean allele number （Na） was 3.5;expected heterozygosity value （He） were higher than observed heterozygosity value （Ho）;mean polymorphism information content （PIC） ranged from 0.479 4 to 0.769 9,which showed these 8 loci posses relatively high information content.Through analysis of genetic structure in primary parent and their first filial,allele and effective allele number,observed heterozygosity and expected heterozygosity values and mean polymorphism information content （PIC） in filial generation were little lower than their primary parents.However,genetic diversity of filial generation is not influenced,and still maintains a good heritability.展开更多
Based on the field observation on the parental behavior of Oriental White Stork (Ciconia boyciana) during their brooding period, this paper describes the breeding style, feeding behavior, water chicks, protect chicks,...Based on the field observation on the parental behavior of Oriental White Stork (Ciconia boyciana) during their brooding period, this paper describes the breeding style, feeding behavior, water chicks, protect chicks, etc. A Ritual “behavior—Culmen Knocking/bill clattering” was observed and which is divided into three styles with deferent meanings. This behavior plays an important role during this season.展开更多
Polymorphism in egg coloration is prominent in the Common Cuckoo (Cuculus canorus) and a common host, the Ashy-throated Parrotbill (Paradoxornis alphonsianus). Egg polymorphism has probably evolved as a consequence of...Polymorphism in egg coloration is prominent in the Common Cuckoo (Cuculus canorus) and a common host, the Ashy-throated Parrotbill (Paradoxornis alphonsianus). Egg polymorphism has probably evolved as a consequence of frequency-dependent selection in both host and parasite, and has, according to human vision, resulted in discrete immaculate white, pale blue and blue egg phenotypes within a single population. However, egg mimicry assessment is not always straightforward, and previous studies have shown that human based comparisons applied to the coloration of bird eggs may be inadequate. Here, we objectively quantify egg color of both parasite and host by spectrophotometry and assess egg mimicry of the Common Cuckoo to the eggs of its Ashy-throated Parrotbill host. Our results revealed that egg reflectance spectra agree well with the assessment based on human vision that cuckoo eggs mimic those of the parrotbill host, in both visible (VIS) and ultraviolet (UV) ranges. However, the white cuckoo egg shows slightly poorer mimicry than the blue cuckoo egg in corresponding host clutches. We suggest that the white parrotbill egg morph (and subsequently the whitish cuckoo egg color) may have evolved after the evolution of the blue egg morph due to strong selection from parasites in the cuckoo-parrotbill system.展开更多
Interaction between a parasite and its host could lead to a co-evolutionary arms race. Cuckoo-host system is among the most studied of all brood parasite systems, but the cuckoos of Asia, on the other hand, are much l...Interaction between a parasite and its host could lead to a co-evolutionary arms race. Cuckoo-host system is among the most studied of all brood parasite systems, but the cuckoos of Asia, on the other hand, are much less well known. China has the most abundant cuckoo species in Asia. Many of these co-occur in sympatric areas, posing a potential risk of mis-identification of cuckoo nestlings, especially in Cuculus species. In this study we have provided a practical criterion to identify cuckoo nestlings species in the field and performed molecular phylogeny to confirm our empirical results. These results indicate that two distinct characteristics of cuckoo nestlings, i.e., the gape color pattern and feather traits can be considered as reliable species identification. To our knowledge, this is the first report for species identification of Cuculus nestlings through molecular analysis.展开更多
The essay expounds the philosophy of Thoreau's "simplify" in aspect of meaning and reason.Closely connected with the relationship between human and nature,it enables us to see the point of a brooding,sim...The essay expounds the philosophy of Thoreau's "simplify" in aspect of meaning and reason.Closely connected with the relationship between human and nature,it enables us to see the point of a brooding,simple and sensible life of Thoreau.The end clarifies on a question:according to Thoreau,what is to have a simplify life? That's to care for little,listen to one's heart and do what one likes.The conclusion comes with an advocation that people keep a simple life with little greed,and take it as an ulti mate cure for the bothering life of today.展开更多
Individuals may gather information about environmental conditions when deciding where to breed in order to maximize their lifetime fitness.They can obtain social information by observing conspecifics and heterospecifi...Individuals may gather information about environmental conditions when deciding where to breed in order to maximize their lifetime fitness.They can obtain social information by observing conspecifics and heterospecifics with similar ecological needs.Many studies have shown that birds can rely on social information to select their nest sites.The location of active nests and the reproductive success of conspecifics and heterospecifics can provide accurate predictions about the quality of the breeding habitat.Some short-lived species can facultatively reproduce two and/or more times within a breeding season.However,few studies have focused on how multiplebrooding individuals select nest sites for their second breeding attempts.In this study,we use long-term data to test whether the Japanese Tit(Parus minor)can use social information from conspecifics and/or heterospecifics(the Eurasian Nuthatch Sitta europaea,the Daurian Redstart Phoenicurus auroreus and the Yellow-rumped Flycatcher Ficedula zanthopygia)to select a nest site for the second breeding attempt.Our results showed that the nest boxes occupied by tits on their second breeding attempt tended to be surrounded by more breeding conspecific nests,successful first nests of conspecifics,and fewer failed first nests of conspecifics than the nest boxes that remained unoccupied(the control group).However,the numbers of breeding heterospecific nests,successful heterospecific nests,and failed heterospecific nests did not differ between the nest boxes occupied by tits on their second breeding attempt and the unoccupied nest boxes.Furthermore,the tits with local successful breeding experience tended to choose areas with more successful first nests of conspecifics than those without successful breeding experience.Thus,we suggest that conspecifics'but not heterospecifics'social information within the same breeding season is the major factor influencing the nest site selection of Japanese Tits during second breeding attempts.展开更多
In 2008 and 2009,we made continuous and repeated breeding surveys of the Scaly-sided Merganser(Mergus squamatus)in the Changbai Mountain range(China side),using a combination of rubber-boat drifting and walking.Each s...In 2008 and 2009,we made continuous and repeated breeding surveys of the Scaly-sided Merganser(Mergus squamatus)in the Changbai Mountain range(China side),using a combination of rubber-boat drifting and walking.Each survey consisted of a census of breeding pairs in the spring and broods in the summer.A total of 1553 km in length of 17 river stretches were surveyed in four different river systems of the Yalujiang,Songhuajiang,Tumenjiang and Mudanjiang rivers.A total of 1354 individuals of the Scaly-sided Merganser were recorded during the both surveys.The breeding density for all the stretches surveyed over both years averaged 0.26 ± 0.30 pairs per km;the population density in the spring averaged 0.75 ± 0.88 individuals per km.According to our survey results,we estimated that the breeding population in the Changbai Mountain range was about 170 breeding pairs of the Scaly-sided Merganser.Three major breeding sites of this bird were found in the Changbai Mountain range in these surveys.展开更多
Brood parasitic birds constitute a model system for the study of coevolution.Such parasites are unique by having evolved unusually thick eggshells for their body size.ick eggshells have been hypothesized to evolve as ...Brood parasitic birds constitute a model system for the study of coevolution.Such parasites are unique by having evolved unusually thick eggshells for their body size.ick eggshells have been hypothesized to evolve as 1) a means of preventing damage to parasite eggs when the brood parasite lays its egg at a distance from the host clutch(the laying damage hypothesis);2) a consequence of host puncture ejection(the puncture resistance hypothesis);3) a means for the brood parasite to allocate calcium to development of a disproportionately large skeleto-muscular system in evicting parasite chicks(the chick vigour hypothesis);or 4) a means of protecting the cuckoo embryo from microorganisms in the nest of the host(the anti-bacterial protection hypothesis).Here we review the literature studying the evolutionary mechanisms promoting thick eggshells in avian brood parasites,and provide proposals for future studies to test their validity.Available data are insu cient to rigorously test exclusive predictions and assumptions of these not necessarily exclusive hypotheses,although the laying damage and the puncture resistance hypotheses seem to currently be the most well supported alternatives.We discuss how quanti cation of rejection modes(grasp ejection,puncture ejection and desertion) may disclose the validity of the puncture resistance hypothesis,and nally we provide perspectives for future research on testing this speci c hypothesis.展开更多
Among more than 75 variants of microcystin （MC）, microcystin-LR （MC-LR） is one of the most common toxins. In this study, the feasibility of using Caenorhabditis elegans to evaluate MC-LR toxicity was studied. C. e...Among more than 75 variants of microcystin （MC）, microcystin-LR （MC-LR） is one of the most common toxins. In this study, the feasibility of using Caenorhabditis elegans to evaluate MC-LR toxicity was studied. C. elegans was treated with MC-LR at different concentrations ranging from 0.1 to 80 μg/L. The results showed that MC-LR could reduce lifespan, delay development, lengthen generation time, decrease brood size, suppress locomotion behavior, and decreases hsp-16-2-gfp expression. The endpoints of generation time, brood size, and percentage of the population expressing hsp-16-2-gfp were very sensitive to 1.0μg/L of MC-LR, and would be more useful for the evaluation of MC-LR toxicity. Furthermore, the tissue-specific hsp-16-2-gfp expressions were investigated in MC-LR-exposed animals, and the nervous system and intestine were primarily affected by MC-LR. Therefore, the generation time, brood size, and hsp-16-2-gfp expression in C. elegans can be explored to serve as valuable endpoints for evaluating the potential toxicity from MC-LR exposure.展开更多
基金Foundation item： This study was supported by the National Natural Science Foundation of China （31472011）ACKNOWLEDGEMENTS We are grateful to Peng ZHANG, Zheng CHEN, Jia-Hui WANG, and Hui-Jia YUAN of Beijing Normal University for field assistance, and staff from Henan Dongzhai National Nature Reserve for help during field work. We also thank editor for revising the English, and the two reviewers for their constructive comments, which have helped to improve the manuscript.
文摘Brooding is a major breeding investment of parental birds during the early nestling stage, and has important effects on the development and survival of nestlings. Investigating brooding behavior can help to understand avian breeding investment strategies. From January to June in 2013 and 2014, we studied the brooding behaviors of long-tailed tits （Aegithalos caudatus glaucogularis） in Dongzhai National Nature Reserve, Henan Province, China. We analyzed the relationships between parental diurnal brooding duration and nestling age, brood size, temperature, relative breeding season, time of day and nestling frequencies during brooding duration. Results showed that female and male long-tailed tit parents had different breeding investment strategies during the early nestling stage. Female parents bore most of the brooding investment, while male parents performed most of the nestling feedings. In addition, helpers were not found to brood nestlings at the two cooperative breeding nests. Parental brooding duration was significantly associated with the food delivered to nestlings （F=86.10, dr=l, 193.94, P〈0.001）, and was longer when the nestlings received more food. We found that parental brooding duration declined significantly as nestlings aged （F=5.99, dr=-1, 50.13, P=0.018）. When nestlings were six days old, daytime parental brooding almost ceased, implying that long- tailed tit nestlings might be able to maintain their own body temperature by this age. In addition, brooding duration was affected by both brood size （F=12.74, dr=-1,32.08, P=0.001） and temperature （F=5.83, df=-l, 39.59, P=-0.021）, with it being shorter in larger broods and when ambient temperature was higher.
基金This work was supported by the National Natural Science Foundation of China(31872961 and 31272330)the biodiversity survey and assessment project of the Ministry of Ecology and Environment of China(2019HB2096001006)the National Forestry and Grassland Administration of China.
文摘In this study,we report an unusual homing behavior of the Sichuan Partridge(Arborophila rufipectus)at the Laojunshan National Nature Reserve,Sichuan Province,China.Hen Sichuan Partridges led the chicks back to the nests where they hatched in the evening and roosted there over night.This behavior lasted 6.7±4.3 nights(range=1–15;n=13)after the chicks hatched.At this stage,the hens became very vigilant to predators and human disturbance.If disturbed,they often abandoned the nests immediately and no longer returned thereafter.The ambient temperature at night during the early brooding period of Sichuan Partridge at our study site was^12.4°C.Our findings suggest that hen Sichuan Partridges may make trade-offs between nest predation risks versus the thermoregulatory needs of their young.
文摘The key techniques of artificial incubation and brooding of Bonasa bonasia during breeding technology promotion was summed up in the paper.Electric incubation and dielectric incubation,electric brooding and dielectric brooding were compared with each other.The results showed that the effect of dielectric inoculation was poor,and there were no significant difference between electric brooding and dielectric brooding.
基金the National Research Development and Innovation Office(NKFIH)of Hungary through the grant K132490 to A.L.and FK137743 to G.S.and by the TKP2020-IKA-07 project financed under the 2020-4.1.1-TKP2020 Thematic Excellence Program.I.P.was supported by theÚNKP-20-4 New National Excellence Program of the Ministry of Innovation and Technology from the Source of the National Research,Development and Innovation Fund.E.V.was supported by the National Office of Research,Development and Innovation(PD-134985)the MSCA EF Seal of Excellence IF-2019 grant by Vinnova,the Swedish Governmental Agency for Innovation Systems(grant number:2021-01102).
文摘Urban areas differ from natural habitats in several environmental features that influence the characteristics of animals living there.For example,birds often start breeding seasonally earlier and fledge fewer offspring per brood in cities than in natural habitats.However,longer breeding seasons in cities may increase the frequency of double-brooding in urban compared with nonurban populations,thus potentially increasing urban birds’annual reproductive output and resulting in lower habitat difference in reproductive success than estimated by studies focusing on first clutches only.In this study,we investigated 2 urban and 2 forests great tit Parus major populations from 2013 to 2019.We compared the probability of double-brooding and the total number of annually fledged chicks per female between urban and forest habitats,while controlling for the effects of potentially confounding variables.There was a trend for a higher probability of double-brooding in urban(44%of females)than in forest populations(36%),although this was not consistent between the 2 urban sites.Females produced significantly fewer fledglings annually in the cities than in the forest sites,and this difference was present both within single-and double-brooded females.Furthermore,double-brooded urban females produced a similar number of fledglings per season as single-brooded forest females.These results indicate that double-brooding increases the reproductive success of female great tits in both habitats,but urban females cannot effectively compensate in this way for their lower reproductive output per brood.However,other mechanisms like increased post-fledging survival can mitigate habitat differences in reproductive success.
基金supported by the National Natural Science Foundation of China(42122045,U23A2036)the National Key Research and Development Program of China(2022-24,2023YFC3108800)。
文摘Dear Editor,Coral reefs sustain high biodiversity and have been referred to as the rainforests of the ocean.However,anthropogenic stressors have led to a global decline of coral reefs,partly due to the increasing scale,frequency,and intensity of coral bleaching events driven by global warming(Henley et al.,2024;Hughes et al.,2018).
文摘The brood-parasitic brown-headed cowbird(Molothrus ater)has one of the shortest incubation periods of any bird.Brown-headed cowbird eggs,and those of other avian brood parasites,tend to be more spherical due to their greater relative width.The traditional explanation for this egg shape is that it,combined with the thicker eggshells,resists host puncture-ejection.However,very few North American hosts of the brownheaded cowbird actually engage in puncture-ejection and therefore wider eggs may instead provide greater contact with a host’s brood patch during incubation,especially in large host nests.We tested whether greater egg width increased mean temperature and reduced temperature variation in brown-headed cowbirds by inserting temperature probes into brown-headed cowbird and house sparrow(Passer domesticus)eggs and placing them into red-winged blackbird(Agelaius phoeniceus)nests.House sparrow eggs are similar in appearance and in length to cowbird eggs,but are not as wide.We found no signifcant relationship between brown-headed cowbird egg width and mean incubation temperature.However,brown-headed cowbird eggs experienced less temperature variation than house sparrow eggs,and within brown-headed cowbird eggs,more spherical eggs experienced less temperature variation when accounting for differences in width.These results suggest that brownheaded cowbirds may have short incubation periods in part because their eggs exhibit less temperature variation over the course of incubation.The brown-headed cowbird’s egg shape may contribute to its accelerated embryonic development rate relative to host eggs of similar size,which explains its ability to hatch in a variety of host nests.
基金supported by the National Key R&D Program of China(2023YFF1304600)supported by the National Natural Science Foundation of China(No.32160242 to JL,32470513 and 32270526 to WL)supported by the 2023 Ningxia Hui Autonomous Region Youth Science and Technology Support Talent Training Project.
文摘With the ongoing acceleration of global urbanization, an increasingly larger proportion of natural habitats are being transformed and utilized by humans. Urbanization has a substantial impact on animal populations, exposing them to greater risks, but also presenting new opportunities and resources. Although the effects of urbanization and brood parasitism on the population dynamics and behavior of host birds have received considerable attention, there has been comparatively little research on how urbanization might affect the risk of brood parasitism on host birds. From April to August in 2023 and 2024, we investigated the risk of brood parasitism on Azure-winged Magpies (Cyanopica cyanus) breeding in the urban center, outskirt, and rural areas of Wuhan City, Hubei Province, China. The results revealed significant differences in the risk of brood parasitism among Azure-winged Magpies in the three regions, with the proportion of magpies parasitized by the Asian Koel (Eudynamys scolopaceus) being found to be significantly lower in the city center (0%) than that in outskirt (3.8%) and rural (11.4%) areas. Our results are consistent with the idea that cities can act as refuges that reduce the risk of brood parasitism experienced by host Azure-winged Magpies. Accordingly, breeding in cities enables Azure-winged Magpies to escape brood parasitism by the Asian Koel.
基金supported by the National Key R&D Program of China(2023YFF1304600)supported by the National Natural Science Foundation of China(Nos.32160242 to JL,32470513 and 32270526 to W.L.)supported by the 2023 Ningxia Hui Autonomous Region Youth Science and Technology Support Talent Training Project。
文摘Avian brood parasitism is a unique reproductive behavior in which parasitic birds depend on other species to incubate their eggs and raise their offspring.In China,there are 20 species of cuckoos in the family Cuculidae,order Cuculiformes,of which 17 species are parasitic cuckoos.This makes China one of the countries with the largest number of parasitic cuckoo species worldwide.Understanding the host utilization of cuckoos provides fundamental data for studying the coevolution of cuckoos with their hosts.We collected information on cuckoo hosts from the literature,photographs provided by birdwatchers,and online short video platforms,combined these data with our field observations,and summarized the parasitic cuckoos and their host species in China.A total of 1155 parasitism events were counted,involving 12 parasitic cuckoo species and 87 bird host species.These hosts belonged to 26 families,among which Muscicapidae was the most diverse with 19 species,accounting for 21.8%of the total hosts,followed by the families Phylloscopidae and Leiothrichidae with 8 species each,accounting for 9.2%of the total hosts recorded.The Common Cuckoo(Cuculus canorus)had the largest number of host taxa with 38 species,accounting for 43.7%of the total host species.This study adds 14 host species that have not been reported in China.However,for five species,the Jacobin Cuckoo(Clamator jacobinus),Banded Bay Cuckoo(Cacomantis sonneratii),Violet Cuckoo(Chrysococcyx xanthorhynchus),Common Hawkcuckoo(Hierococcyx varius),and Whistling Hawk-cuckoo(Hierococcyx nisicolor),information regarding host utilization is still lacking.
基金funded by the Education Department of Hainan Province(no.HnjgY 2022-12)the National Natural Science Foundation of China(no.32260127).
文摘Alarm calls in bird vocalizations serve as acoustic signals announcing danger.Owing to the convergent evolution of alarm calls,some bird species can beneft from eavesdropping on certain parameters of alarm calls of other species.Vocal mimicry,displayed by many bird species,aids defense against predators and may help brood parasites during parasitism.In the coevolutionary dynamics between brood parasites,such as the common cuckoo(Cuculus canorus),and their hosts,female cuckoo vocalizations can induce hosts to leave the nest,increasing the probability of successful parasitism and reducing the risk of host attacks.Such cuckoo calls were thought to mimic those of the sparrowhawk.However,owing to their similarity to alarm calls,we propose a new hypothesis:Female cuckoos cheat their hosts by mimicking the parameters of the host alarm call.In this study,we tested this new hypothesis and the sparrowhawk mimicry hypothesis simultaneously by manipulating the syllable rate in male and female common cuckoo vocalizations and playing them in front of the host Oriental reed warbler(Acrocephalus orientalis)for examination.The results indicate that similar to a normal female cuckoo call,a female call with a reduced syllable rate prompted the hosts to leave their nests more frequently and rapidly than male cuckoo calls.Additionally,the male cuckoo calls with increased syllable rate did not prompt the host to leave their nests more frequently or quickly compared with the male cuckoo calls with a normal syllable rate.Our results further confrm that female common cuckoos mimic the vocalizations of Eurasian sparrowhawks(Accipiter nisus),reveal the function mechanisms underlying such mimicry,and support the theory of imperfect mimicry.
基金supported by Grants from the Agencia Nacional de Promoción Científica y Tecnológica,from Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET)and the University of Buenos Aires.
文摘For songbirds,the post-fledging period is critical for development and survival,as young must learn to get food,practice flying,and identify predators to become independent from their parents and disperse or migrate.Obligate avian brood parasites,like cuckoos and cowbirds,lay eggs in nests of other bird species that provide parental care until the parasite’s young become independent.The information on the post-fledging period in songbirds is limited due to the difficulty in following and observing fledglings and it is even scarcer for brood parasites.We studied the behavior,survival,and age of independence of Shiny Cowbird(Molothrus bonariensis)fledglings raised by 2 hosts that differ markedly in body size:the House Wren(Troglodytes aedon)and the Chalk-Browed Mockingbird(Mimus saturninus).We radio-tracked individuals from a few days before they left the nest until they disappeared from the natal territory.We found:(1)chicks left the nest when they were 11-15 days of age and the age of fledgling did not differ between the 2 host species,(2)after leaving the nest,they spent most of the time perched in a hidden place without begging but as they grew,the proportion of time perched without begging decreased and begging in hidden and exposed places increased,(3)we observed approaches between adult parasitic females and young in host territories,(4)young abandoned the host territory and joined conspecific flocks when they were 35-39 days of age,and(5)the estimated post-fledging survival was between 12.5%and 20.8%.
基金supported by the National Natural Science Foundation of China (No. 31071938, 31101646)Key Project of Chinese Ministry of Education (No. 212136)+1 种基金the China Postdoctoral Science Foundation funded project (20110490967)the Program for New Century Excellent Talents in University (NCET-10-0111)
文摘In this exposé we provide the first review of host use by brood parasitic cuckoos in a multiple-cuckoo system in China, based on our own long-term field data and a compilation of observations obtained from the literature. In total, we found that 11 species of cuckoos utilized altogether 55 host species. These hosts belong to 15 families, in which Sylviidae, Turdidae and Timaliidae account for 22.6%, 20.8% and 17.0% of parasitism records, respectively. The Common Cuckoo (Cuculus canorus) had the widest range of host species, accounting for 45.5% of the total number of parasitized species (25 in 10 families) of all parasitism records and is the most frequent brood parasite in the country. Cuckoo species differed in their egg coloration and the extent of egg polymorphism with most of them, e.g. the Common Cuckoo, the Lesser Cuckoo (C. poliocephalus) and the Plaintive Cuckoo (Cacomantis merulinus) laying well mimetic eggs with respect to their hosts based on human being’s visual observations, while others such as the Large Hawk-cuckoo (C. sparverioides), the Himalayan Cuckoo (C. saturatus) and the Asian Emerald Cuckoo (Chrysococcyx maculatus) usually laid non-mimetic eggs. The use of cuckoo hosts and egg color variation in China are compared with those in other parts of their ranges in Asia.
基金Supported by Technology Innovation Projects from Science and Tech-nology Department of Guangdong Province (2008A023700011)~~
文摘Genetic variations of three species from primary parent （OI Q,SIS Q,Kona Bay Q） and their first filial generation （OI Z,SIS Z,Kona Bay Z） of Litopenaeus vannamei were detected using microsatellite marker technique.The amplified products of genomic DNA with 8 microsatellite makers indicated that 8 loci presents polymorphism,the number of total alleles were 28 in 6 species;the number of allele of every loci was 2 to 6;mean allele number （Na） was 3.5;expected heterozygosity value （He） were higher than observed heterozygosity value （Ho）;mean polymorphism information content （PIC） ranged from 0.479 4 to 0.769 9,which showed these 8 loci posses relatively high information content.Through analysis of genetic structure in primary parent and their first filial,allele and effective allele number,observed heterozygosity and expected heterozygosity values and mean polymorphism information content （PIC） in filial generation were little lower than their primary parents.However,genetic diversity of filial generation is not influenced,and still maintains a good heritability.
文摘Based on the field observation on the parental behavior of Oriental White Stork (Ciconia boyciana) during their brooding period, this paper describes the breeding style, feeding behavior, water chicks, protect chicks, etc. A Ritual “behavior—Culmen Knocking/bill clattering” was observed and which is divided into three styles with deferent meanings. This behavior plays an important role during this season.
基金supported by the National Natural Science Foundation of China (Nos. 31071938 and 31272328 to WL, 31101646 and 31260514 to CY)Program for New Century Excellent Talents in University (NCET-10-0111 to WL)Key Project of Chinese Ministry of Education (No. 212136 to CY)
文摘Polymorphism in egg coloration is prominent in the Common Cuckoo (Cuculus canorus) and a common host, the Ashy-throated Parrotbill (Paradoxornis alphonsianus). Egg polymorphism has probably evolved as a consequence of frequency-dependent selection in both host and parasite, and has, according to human vision, resulted in discrete immaculate white, pale blue and blue egg phenotypes within a single population. However, egg mimicry assessment is not always straightforward, and previous studies have shown that human based comparisons applied to the coloration of bird eggs may be inadequate. Here, we objectively quantify egg color of both parasite and host by spectrophotometry and assess egg mimicry of the Common Cuckoo to the eggs of its Ashy-throated Parrotbill host. Our results revealed that egg reflectance spectra agree well with the assessment based on human vision that cuckoo eggs mimic those of the parrotbill host, in both visible (VIS) and ultraviolet (UV) ranges. However, the white cuckoo egg shows slightly poorer mimicry than the blue cuckoo egg in corresponding host clutches. We suggest that the white parrotbill egg morph (and subsequently the whitish cuckoo egg color) may have evolved after the evolution of the blue egg morph due to strong selection from parasites in the cuckoo-parrotbill system.
基金supported by the National Natural Science Foundation of China (No. 31071938, 31101646)the Key Project of the Chinese Ministry of Education (No. 212136)the Program for New Century Excellent Talents in University(NCET-10-0111)
文摘Interaction between a parasite and its host could lead to a co-evolutionary arms race. Cuckoo-host system is among the most studied of all brood parasite systems, but the cuckoos of Asia, on the other hand, are much less well known. China has the most abundant cuckoo species in Asia. Many of these co-occur in sympatric areas, posing a potential risk of mis-identification of cuckoo nestlings, especially in Cuculus species. In this study we have provided a practical criterion to identify cuckoo nestlings species in the field and performed molecular phylogeny to confirm our empirical results. These results indicate that two distinct characteristics of cuckoo nestlings, i.e., the gape color pattern and feather traits can be considered as reliable species identification. To our knowledge, this is the first report for species identification of Cuculus nestlings through molecular analysis.
文摘The essay expounds the philosophy of Thoreau's "simplify" in aspect of meaning and reason.Closely connected with the relationship between human and nature,it enables us to see the point of a brooding,simple and sensible life of Thoreau.The end clarifies on a question:according to Thoreau,what is to have a simplify life? That's to care for little,listen to one's heart and do what one likes.The conclusion comes with an advocation that people keep a simple life with little greed,and take it as an ulti mate cure for the bothering life of today.
基金financed by the National Natural Science Foundation of China(31971402 to H.Wang,32001094 to J.Yu,31870368 to K.Zhang)the High-level Startup Talents Introduced Scientific Research Fund Project of Baotou Teacher's College,China(No.BTTCRCQD2024-C34)。
文摘Individuals may gather information about environmental conditions when deciding where to breed in order to maximize their lifetime fitness.They can obtain social information by observing conspecifics and heterospecifics with similar ecological needs.Many studies have shown that birds can rely on social information to select their nest sites.The location of active nests and the reproductive success of conspecifics and heterospecifics can provide accurate predictions about the quality of the breeding habitat.Some short-lived species can facultatively reproduce two and/or more times within a breeding season.However,few studies have focused on how multiplebrooding individuals select nest sites for their second breeding attempts.In this study,we use long-term data to test whether the Japanese Tit(Parus minor)can use social information from conspecifics and/or heterospecifics(the Eurasian Nuthatch Sitta europaea,the Daurian Redstart Phoenicurus auroreus and the Yellow-rumped Flycatcher Ficedula zanthopygia)to select a nest site for the second breeding attempt.Our results showed that the nest boxes occupied by tits on their second breeding attempt tended to be surrounded by more breeding conspecific nests,successful first nests of conspecifics,and fewer failed first nests of conspecifics than the nest boxes that remained unoccupied(the control group).However,the numbers of breeding heterospecific nests,successful heterospecific nests,and failed heterospecific nests did not differ between the nest boxes occupied by tits on their second breeding attempt and the unoccupied nest boxes.Furthermore,the tits with local successful breeding experience tended to choose areas with more successful first nests of conspecifics than those without successful breeding experience.Thus,we suggest that conspecifics'but not heterospecifics'social information within the same breeding season is the major factor influencing the nest site selection of Japanese Tits during second breeding attempts.
基金sponsored by the Rufford Small Grant of the Rufford Foundation
文摘In 2008 and 2009,we made continuous and repeated breeding surveys of the Scaly-sided Merganser(Mergus squamatus)in the Changbai Mountain range(China side),using a combination of rubber-boat drifting and walking.Each survey consisted of a census of breeding pairs in the spring and broods in the summer.A total of 1553 km in length of 17 river stretches were surveyed in four different river systems of the Yalujiang,Songhuajiang,Tumenjiang and Mudanjiang rivers.A total of 1354 individuals of the Scaly-sided Merganser were recorded during the both surveys.The breeding density for all the stretches surveyed over both years averaged 0.26 ± 0.30 pairs per km;the population density in the spring averaged 0.75 ± 0.88 individuals per km.According to our survey results,we estimated that the breeding population in the Changbai Mountain range was about 170 breeding pairs of the Scaly-sided Merganser.Three major breeding sites of this bird were found in the Changbai Mountain range in these surveys.
基金supported by National Natural Science Foundation of China (Nos.31071938 to AA,BGS and WL,31272328 to WL,31101646 and 31260514 to CY)Program for New Century Excellent Talents in University (NCET-10-0111 to WL)BGS and FF were funded by the Research Council of Norway (218144)
文摘Brood parasitic birds constitute a model system for the study of coevolution.Such parasites are unique by having evolved unusually thick eggshells for their body size.ick eggshells have been hypothesized to evolve as 1) a means of preventing damage to parasite eggs when the brood parasite lays its egg at a distance from the host clutch(the laying damage hypothesis);2) a consequence of host puncture ejection(the puncture resistance hypothesis);3) a means for the brood parasite to allocate calcium to development of a disproportionately large skeleto-muscular system in evicting parasite chicks(the chick vigour hypothesis);or 4) a means of protecting the cuckoo embryo from microorganisms in the nest of the host(the anti-bacterial protection hypothesis).Here we review the literature studying the evolutionary mechanisms promoting thick eggshells in avian brood parasites,and provide proposals for future studies to test their validity.Available data are insu cient to rigorously test exclusive predictions and assumptions of these not necessarily exclusive hypotheses,although the laying damage and the puncture resistance hypotheses seem to currently be the most well supported alternatives.We discuss how quanti cation of rejection modes(grasp ejection,puncture ejection and desertion) may disclose the validity of the puncture resistance hypothesis,and nally we provide perspectives for future research on testing this speci c hypothesis.
基金supported by the National Natural Sci-ence Foundation of China (No. 30771113, 30870810)the Doctoral Program of Higher Education of China (No.20050286035)+1 种基金the Jiangsu 333 Project Foundation (No.07056)the Natural Science Foundation of Jiangsu Province (No. BK2006107, BK2008320)
文摘Among more than 75 variants of microcystin （MC）, microcystin-LR （MC-LR） is one of the most common toxins. In this study, the feasibility of using Caenorhabditis elegans to evaluate MC-LR toxicity was studied. C. elegans was treated with MC-LR at different concentrations ranging from 0.1 to 80 μg/L. The results showed that MC-LR could reduce lifespan, delay development, lengthen generation time, decrease brood size, suppress locomotion behavior, and decreases hsp-16-2-gfp expression. The endpoints of generation time, brood size, and percentage of the population expressing hsp-16-2-gfp were very sensitive to 1.0μg/L of MC-LR, and would be more useful for the evaluation of MC-LR toxicity. Furthermore, the tissue-specific hsp-16-2-gfp expressions were investigated in MC-LR-exposed animals, and the nervous system and intestine were primarily affected by MC-LR. Therefore, the generation time, brood size, and hsp-16-2-gfp expression in C. elegans can be explored to serve as valuable endpoints for evaluating the potential toxicity from MC-LR exposure.
