Rates of brood parasitism vary extensively among host species and populations of a single host species. In this study, we documented and compared parasitism rates of two sympatric hosts, the Oriental Reed Warbler （Ac...Rates of brood parasitism vary extensively among host species and populations of a single host species. In this study, we documented and compared parasitism rates of two sympatric hosts, the Oriental Reed Warbler （Acrocephalus orientalis） and the Reed Parrotbill （Paradoxornis heudei）, in three populations in China. We found that the Common Cuckoo （Cuculus canorus） is the only parasite using both the Oriental Reed Warbler and Reed Parrotbill as hosts, with a parasitism rate of 22.4%-34.3% and 0%-4.6%, respectively. The multiple parasitism rates were positively correlated with local parasitism rates across three geographic populations of Oriental Reed Warbler, which implies that higher pressure of parasitism lead to higher multiple parasitism rate. Furthermore, only one phenotype of cuckoo eggs was found in the nests of these two host species. Our results lead to two conclusions： （1） The Oriental Reed Warbler should be considered the major host of Common Cuckoo in our study sites; and （2） obligate parasitism on Oriental Reed Warbler by Common Cuckoo is specialized but flexible to some extent, i.e., using Reed Parrotbill as a secondary host. Further studies focusing on egg recognition and rejection behaviour of these two host species should be conducted to test our predictions.展开更多
Background: The success of cuckoo parasitism is thought to depend largely on the extent of egg matching between cuckoo and host eggs, since poor-matching cuckoo egg would lead to more frequent egg rejection by the hos...Background: The success of cuckoo parasitism is thought to depend largely on the extent of egg matching between cuckoo and host eggs, since poor-matching cuckoo egg would lead to more frequent egg rejection by the host. In this study, we investigated how egg-spot matching between the Common Cuckoo(Cuculus canorus) and its host, the Oriental Reed Warbler(Acrocephalus orientalis) is affected by the local parasitism rate, nest availability in breeding synchronization and egg rejection.Methods: We used the paired design of parasitized and their nearest non-parasitized nests where breeding occurred simultaneously to compare egg-spot matching. The image analysis was used to compare four eggshell pattern variables, namely spot size, density, coverage on the different areas of egg surface, and the distribution on the whole egg surface. Egg recognition experiments were conducted to test the effect of egg spots on egg rejection by the host.Results: Our results show that much better matching in almost all spot parameters tested on the side of the egg and the spot distribution on the whole egg occurred in parasitized nests than in non-parasitized nests. Matching of spot density between cuckoo and host eggs in parasitized nests increased with the synchronization between temporal availability of nests and the egg-laying period of female cuckoos. Egg recognition experiments in which the warbler eggs were deliberately painted with extra spots led to a significantly higher egg rejection rate(78.3%) than of unpainted eggs.Conclusion: Our data suggest that both the high temporal encounter rate between cuckoo and warbler nests as well as the high egg rejection ability of the host are important factors for egg-spot matching of the cuckoos.展开更多
Ten populations of Radopholus similis from different ornamental hosts were tested for their parasitism and pathogenicity to water spinach （Ipomoea aquatic）, malabar spinach （Basella rubra）, and squash （Cucurbita ...Ten populations of Radopholus similis from different ornamental hosts were tested for their parasitism and pathogenicity to water spinach （Ipomoea aquatic）, malabar spinach （Basella rubra）, and squash （Cucurbita moschata） in pots. The re- sults showed all three plants were new hosts of R. similis. Growth parameters of plants inoculated with nematodes were significantly lower than those of healthy control plants. All R. similis populations were pathogenic to the three plants, but pathogenicity differed among populations from different hosts. The same R. similis populations also showed different pathogenic effects in the three different plants. RadN5 population from Anthurium andraeanum had the highest pathoge- nicity to the three studied plants. RadN1 from A. andraeanum had the lowest pathogenicity to squash and RadN7 from Chrysalidocarpus lutesens had the lowest pathogenicity to water spinach and malabar spinach. R. similis is usually associated with root tissues, but here we report that it could be found to move and feed in the stem bases of all three studied plants. Sequence and phylogenetic analyses of DNA markers of the 18S rRNA, 28S rRNA, ITS rRNA, and mitochondrial DNA gene sequences of ten R. similis populations revealed significant genetic diversity. RadN5 and RadN6 populations from anthurium showed a close genetic relationship and could be distinguished from other populations by PCR-RFLP. At the same time, RadN5 and RadN6 populations were the most pathogenic to three studied plants. These results confirm the existence of large biological variability and molecular diversity among R. similis populations from the same or different hosts, and these characteristics are related to pathogenic variability.展开更多
Background:Red-winged Blackbirds(Agelaius phoeniceus),hereafter red-wings,are much less frequently parasitized by Brown-headed Cowbirds(Molothrus ater)in eastern North America than in central North America and had not...Background:Red-winged Blackbirds(Agelaius phoeniceus),hereafter red-wings,are much less frequently parasitized by Brown-headed Cowbirds(Molothrus ater)in eastern North America than in central North America and had not been recorded as hosts in our study area in southeastern Pennsylvania.Although hosts of Old World cuckoos(Cuculidae)often show geographic variation in egg rejection behavior,cowbird hosts typically exhibit uniform responses of all acceptance or all rejection of cowbird eggs.Thus,geographic variation in cowbird parasitism frequencies might reflect a different behavioral response to parasitism by hosts where only some populations reject parasitism.In this study,we tested whether egg rejection behavior may explain the lack of parasitism observed in our eastern red-wing population,which may provide insight into low parasitism levels across eastern North America.Methods:We parasitized red-wing nests with model cowbird eggs to determine their response to parasitism.Nests were tested across three nest stages and compared to control nests with no manipulations.Because rejection differed significantly by stage,we compared responses separately for each nest stage.We also monitored other songbird nests to identify parasitism frequencies on all potential hosts.Results:Red-wings showed significantly more rejections during the building stage,but not for the laying and incubation stages.Rejections during nest building involved mostly egg burials,which likely represent a continuation of the nest building process rather than true rejection of the cowbird egg.Excluding these responses,red-wings rejected 15%of cowbird eggs,which is similar to rejection levels from other studies and populations.The overall parasitism frequency on 11 species surveyed in our study area was only 7.4%.Conclusions:Egg rejection behavior does not explain the lack of parasitism on red-wings in our eastern population.Alternatively,we suggest that cowbird preference for other hosts and the low abundance of cowbirds in the east might explain the lack of parasitism.Future research should also explore cowbird and host density and the makeup of the host community to explain the low levels of parasitism on red-wings across eastern North America because egg rejection alone is unlikely to explain this broad geographic trend.展开更多
The Plaintive Cuckoo(Cacomantis merulinus) is a widespread brood parasite in Asia, but no data on host species utilization in Bangladesh exist. By searching for nests of all possible host species of the Plaintive Cuck...The Plaintive Cuckoo(Cacomantis merulinus) is a widespread brood parasite in Asia, but no data on host species utilization in Bangladesh exist. By searching for nests of all possible host species of the Plaintive Cuckoo at Jahangirnagar university campus, north of Dhaka, we were able to determine which hosts were used in this area. We found that the Common Tailorbird(Orthotomus sutorius) was the only potential host used by Plaintive Cuckoos, and parasitism rate was rather high(31.3 %, n = 16). However, both host and cuckoo breeding success was poor(0 %, n = 16) due to frequent nest predation. Details on host and cuckoo egg appearance are provided. Our findings indicate that Common Tailorbirds are common hosts of the Plaintive Cuckoo in Central Bangladesh.展开更多
Common Cuckoos(Cuculus canorus) parasitize nests of small passerines.e Cuckoo chicks cause the death of their nest-mates when evicting eggs or nestlings from the nests;consequently,hosts su er from a high loss of repr...Common Cuckoos(Cuculus canorus) parasitize nests of small passerines.e Cuckoo chicks cause the death of their nest-mates when evicting eggs or nestlings from the nests;consequently,hosts su er from a high loss of reproduction.Host adaptations against parasitism,e.g.,by egg discrimination behavior,and cuckoo counter-adaptations to hosts,e.g.,by mimetic eggs,are often regarded as a result of the arms race between the two interacting species.In Hungary Great Reed Warblers(Acrocephalus arundinaceus) are the main hosts of cuckoos,su ering from heavy parasitism(ca.40-65%).e Oriental Reed Warbler(A.orientalis),formerly a subspecies of the Great Reed Warbler(A.a.orientalis),is also a highly parasitized host in Japan(25-40%).We compared main characteristics of Cuckoo parasitism in these two distant areas from the Western and Eastern Palearctic by comparing cuckoo egg mimicry.We measured color characteristics of host and parasitic eggs by spectrophotometer.Visual modeling revealed lower chromatic distances between Cuckoo and host eggs in Hungary than in Japan,but high variation both in host and Cuckoo eggs may cause matching problems in Hungary.Achromatic(brightness) di erence between host and Cuckoo eggs were lower in Japan than in Hungary,and it proved to be the most important factor a ecting egg rejection.Hosts rejected Cuckoo eggs at similar frequencies(37% and 35% in Hungary and Japan,respectively).Host adaptation,i.e.,egg rejection behavior,seems to be preceding Cuckoo counter-adaptations to hosts in Japan.We suggest that the Cuckoo-Great/Oriental Reed Warbler relationships developed in alternative ways in Japan and Hungary,and they represent di erent stages of their arms race.展开更多
A double parasitism(isopod Cymothoidae and copepod Pennellidae) on black-barred halfbeak fish,Hemiramphus far,was recorded from Pazhayar coastal waters(southeast coast of India) during September 2008.This is the first...A double parasitism(isopod Cymothoidae and copepod Pennellidae) on black-barred halfbeak fish,Hemiramphus far,was recorded from Pazhayar coastal waters(southeast coast of India) during September 2008.This is the first report from this region and the infection is discussed in relation to environmental and biological parameters.展开更多
Living and/or non-living animal models are often used as stimuli to observe the behavioral responses of the target animals.In the past,parasites,predators,and harmless controls have been used to test host anti-parasit...Living and/or non-living animal models are often used as stimuli to observe the behavioral responses of the target animals.In the past,parasites,predators,and harmless controls have been used to test host anti-parasitism defense behavior,and their taxidermy specimens have been widely used as a set of standard methods for the study of avian brood parasitism.In recent years,with the rapid development of 3D-printing technology,3D-printed bird models are expected to be applied as a standard method in the study of avian brood parasitism.To evaluate the use of 3D-printed models,this study tests the reaction of Oriental Reed Warbler(Acrocephalus orientalis)towards predators,parasites,or controls,and compares the reaction among different nest intruders and between taxidermy specimens and 3D-printed animal models.It was found that the Oriental Reed Warbler responded most aggressively to the parasite,followed by predator,and finally the control;the results were consistent between the reaction to taxidermy specimens and 3D-printed animal models,indicating that 3D-printed models could serve as a substitute for taxidermy specimens.We propose a series of advantages of using 3D-printed models and suggest them to be a standard method for widespread use in future studies of avian brood parasitism.展开更多
The effects of parasitic capacitance in induction motor system are unnoticed when it is fed from the AC line, but they are obvious when supplied directly from a PWM inverter. Consequently, many parasitic problems occu...The effects of parasitic capacitance in induction motor system are unnoticed when it is fed from the AC line, but they are obvious when supplied directly from a PWM inverter. Consequently, many parasitic problems occur, such as motor to earth leakage current, bearing current, incoming line current distortion and uneven distribution of electrical stresses along the winding. On the basis of the uniform transmission line principle, a complete equivalent circuit of the PWM inverter fed motor system is presented, based on which all the capacitive parasitic problems mentioned above are analyzed and simulated by means of PSPICE. All the results are consistent with the existing ones.展开更多
Introduction: Intestinal parasitism has been a challenge to overcome for the Mexican deworming campaign and this study determined the prevalence of these infections in schoolchildren treated with albendazole in Northw...Introduction: Intestinal parasitism has been a challenge to overcome for the Mexican deworming campaign and this study determined the prevalence of these infections in schoolchildren treated with albendazole in Northwestern Mexico. Methods: Study sites in marginal conditions, with gastrointestinal infections and albendazole intervention were selected. The Faust and Kato Katz techniques were used to identify the parasites spp. and the NCSS software was used for statistical analysis. Results: A total of 450, 389 and 364 schoolchildren participated in 2005, 2006, and 2007 respectively during this study. The mean age was 7.9 (±1.3). The estimated prevalences were of 42%, 30% and 37% for protozoa infections, and 11%, 12% and 11% for helminth infections in 2005, 2006 and 2007 respectively. Conclusion: The education strategies should be integrated into the Mexican deworming campaign.展开更多
The reniform nematode (RN), Rotylenchulus reniformis, is an agriculturally important pest with a broad host range that results in a large economic impact in tropical, subtropical and in warm temperate zones. In an ini...The reniform nematode (RN), Rotylenchulus reniformis, is an agriculturally important pest with a broad host range that results in a large economic impact in tropical, subtropical and in warm temperate zones. In an initial effort to understand the transcriptome and gene expression in RN, we present EST results that reveal numerous putative parasitism-related genes some of which play roles in plant cell wall modification. The characterized contigs included 8362 (40.6%) matches to unique proteins. Coding contigs predicted were 10,656 (51.7%) or 3079 (14.9%), that was similar to those identified in Brugia malayi and Caenorhabditis elegans as reference organisms respectively. Specific transcripts studied in more detail include putative plant parasitism genes, prominent among them were several plant cell wall modification genes. Contigs matching 14 parasitism genes found in sedentary endoparasitic nematodes included expansins, hexosaminidase, glycosyl hydrolases family, 14-3-3 protein, xylanases, glutathione peroxidase, pectate lyase, β-1,4-endoglucanase, major sperm protein, aminopeptidase, c-type lectin, chitin synthase, FMR famide-like peptide, and calreticulin. These genes function in suppression of host defenses and development of feeding sites.展开更多
The strategies used by parasitic cuckoos to fool their hosts have intrigued naturalists and ornithologists for centuries. Here I review some of the tricks used by Australian parasitic cuckoos to increase host nest ava...The strategies used by parasitic cuckoos to fool their hosts have intrigued naturalists and ornithologists for centuries. Here I review some of the tricks used by Australian parasitic cuckoos to increase host nest availability, access host nests, and fool their hosts into accepting their eggs and chicks. Some of these strategies are widely used by cuckoo species around the world, but other traits, such as cryptic eggs and mimetic chicks, appear to be largely restricted to the Australasian cuckoos. Generalist cuckoos face greater challenges than specialists if they must fool multiple host species, and this provides a possible explanation for why different species of cuckoos have evolved different strategies for host deception.展开更多
Unlike most brood parasites, several species of cowbird (Molothrus) are generalists that parasitize multiple host species across their range and within the same communities; likewise, there is little evidence that ind...Unlike most brood parasites, several species of cowbird (Molothrus) are generalists that parasitize multiple host species across their range and within the same communities; likewise, there is little evidence that individuals within a population specialize on host species. This situation has variously been attributed to the recency of cowbird evolution (the 'evolutionary lag' hypothesis) or to hidden costs of rejection by hosts (the 'equilibrium' hypothesis). Both hypotheses have some support as cowbirds are indeed a relatively young clade compared with more specialized cuckoos and cowbirds are capable of sophisticated behaviors such as retaliation against rejection ('mafia' behaviors) that would select for acceptance of cowbird eggs. Nevertheless, many species in the Americas have evolved specialized defenses against cowbird parasitism, almost all of which live in more open habitats (e. g., grasslands, shrublands, riparian strips), which indicates that coevolutionary processes can operate in ways that select for host defenses in spite of cowbird counterdefenses. We propose that the structure of landscapes in North America may explain why forest-nesting birds lack defenses against parasitism and reinforce the long-term maintenance of generalized brood parasitism in cowbirds. Because cowbirds require open habitats in which to feed, they are rare or absent in large forest tracts, which dominate much of the forest cover of the Americas. These tracts act as 'source habitats' that produce surplus young that recolonize populations in smaller, fragmented forest patches in which rates of both cowbird parasitism and nest predation are very high ('sink' habitats). Evolution of antiparasite adaptations would be very slow in this situation because most hosts are produced in areas where there is little or no cowbird parasitism. In addition, the interplay of host breeding dispersal, source-sink metapopulation dynamics, and fragmented forest habitat could further deter the evolution of host defenses against parasitism. Therefore, as long as large forest tracts remain widespread in North America, most forest birds will likely continue to lack defenses against cowbird parasitism, guaranteeing a steady supply of na ve hosts in forest habitats, even in fragmented landscapes. This situation will, in turn, favor host generalist cowbirds that actively avoid more open habitats in favor of parasitizing forest bird communities. These forest communities may also act as source populations for cowbirds, which might pump surplus generalist cowbirds into more open habitats further slowing the coevolutionary process. As long as large forest tracts are a common part of the landscape, generalist parasitism may persist indefinitely.展开更多
正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled &q...正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments展开更多
Tea tortrix, Homona coffearia Nietner (Lepidoptera: Tortricidae), is a seasonal pest of tea in Sri Lanka. Though it is active in dry weather, it is observed that populations do occur in wet weather causing serious dam...Tea tortrix, Homona coffearia Nietner (Lepidoptera: Tortricidae), is a seasonal pest of tea in Sri Lanka. Though it is active in dry weather, it is observed that populations do occur in wet weather causing serious damage to tea. The parasite, Macrocentrus homonae Nixon (Hymenoptera: Braconidae), controls the tortrix populations, but the efficiency of Macrocentrus has been reduced on account of hyperparasites in recent times. Level of hyperparasitism was studied in some tea tortrix prone areas in the up country region to study how this affected the tortrix populations during wet weather. The hyperparasitism varied during the study period of which average values observed ranged from 35% to 52% in the plantations studied. A negative linear relationship was observed between the average number of parasite cocoons in a cocoon mass and the percentage hyperparasitism. Three generations of tortrix were evident during the study period of May to November 2005. It is observed that tortrix populations do occur in dry and wet weather, and that hyperparasitism has been identified as the major cause affecting the efficient control of tortrix by the parasite. Possibilities of tea tortrix control in wet weather are discussed.展开更多
正Invited participants on the 3rd International Symposium on Avian Brood Parasitism, sponsored by Hainan Normal University (HNU), China, Norwegian University of Science and Technology (NTNU), Norway, the Research Coun...正Invited participants on the 3rd International Symposium on Avian Brood Parasitism, sponsored by Hainan Normal University (HNU), China, Norwegian University of Science and Technology (NTNU), Norway, the Research Council of Norway, and China Ornithological Society (COS).展开更多
Objective:To ascertain the level of intestinal parasites vis-a-vis the quality of housing and water supply,and sanitary conditions among the people of Kuraje village in Zamfara state. Methods:The study was cross secti...Objective:To ascertain the level of intestinal parasites vis-a-vis the quality of housing and water supply,and sanitary conditions among the people of Kuraje village in Zamfara state. Methods:The study was cross sectional in nature.Individual households were selected using systematic random sampling methods and pre-tested questionnaires were administered to all the members of each household.Stool samples were collected and processed using standard laboratory procedures.Housing conditions,sources of water and sanitary conditions of the households were also inspected.Results were analysed using Epi Info 2006 model.Results: The prevalence of intestinal parasites was 67.0%(347/519).72.3%(251/347),17.0%(59/347),and 10.7%(37/347) had one,two and three or more parasites,respectively.The associated factors with intestinal parasites were poor housing and sanitary conditions,lack of potable water and illiteracy.The commonest parasites encountered were hookworm(22.0%),Ascaris lumbricoides (18.5%),and Strongyloides stercoralis(15.6%) while the least common was Enterobius vermicularis (1.6%).Others were Giardia lamblia(5.7%),Hymenolepsis nana(5.0%),Trichuris trichiura(8.8%), Entamoeba histolytica(14.4%) and Schistosoma mansoni(8.4%).Conclusions:The infection rate of intestinal parasites in Kuraje village is high.More efforts should be intensified towards improvement in sanitary and housing standards,supply of potable water and institution of a more comprehensive literacy programme for the people of the community.展开更多
Captivity of wild animals and restriction of their movement can lead to stress, resulting in suppressed immune response and reduced disease resistance ability. Wild animals in zoological gardens can predominately affe...Captivity of wild animals and restriction of their movement can lead to stress, resulting in suppressed immune response and reduced disease resistance ability. Wild animals in zoological gardens can predominately affected by various gastro-intestinal parasites. This study was therefore, conducted to determine occurrence, identify types and assess seasonal variation of gastrointestinal parasites in captive animals at the Zoological garden of Haramaya University. The study involved a retrospective investigation of zoo records and fecal examinations. Twenty two fecal samples were collected in December, 2013 from all the animals in the garden and examined using concentration and fecal culture techniques. Sampling was repeated after four months in April, 2014 to assess seasonal variations of the parasites. The result from the retrospective study showed death of 21 animals in the last five years. Fecal examination confirmed presence of gastrointestinal parasites with an overall mean prevalence rate of 73.8%. A total of 9 parasite taxa were identified of which 6 (66.67%) and 4 (33.33%) were helminths and protozoa respectively. No Cestode and Trematode species were recovered. <i>Trichuris spp.</i>, <i>Toxocara spp.</i>, <i>Strongyloides spp.</i>, <i>Toxascaris leonine</i>, <i>Passalurus ambiguous</i> and <i>Ascaridia spp.</i> were the helminth parasites observed in the garden. <i>Entamoeba spp.</i>, <i>Isospora spp.</i> and <i>Eimeria spp.</i> were the protozoan parasites encountered. No remarkable seasonal variation in parasitic infection was noticed in the garden. The study revealed occurrence of gastrointestinal parasites in the zoological garden, most of which are zoonotic and hence future studies are needed to determine risks of cross-transmission.展开更多
The shiny cowbird Molothrus bonariensis parasitizes many species with different life-history traits and has a detrimental effect on the survival of the progeny of the hosts.In response,hosts have developed numerous an...The shiny cowbird Molothrus bonariensis parasitizes many species with different life-history traits and has a detrimental effect on the survival of the progeny of the hosts.In response,hosts have developed numerous antiparasitic defenses.Here,we examined the effects of brood parasitism by shiny cowbird on the clutch and brood sizes(83 nests)in a small host,the black-backed water tyrant Fluvicola albiventer.We also studied whether the death of parasite nestlings was related to the care of the foster parents and whether the host had any antiparasitic defense against the shiny cowbird.Our results indicate that brood parasitism significantly decreased the host hatching and fledging successes.The majority of nest failures(57%)were caused by brood parasitism.Shiny cowbird parasitism occurred in 52%of nests and the intensity of parasitism was 1.23±0.53 eggs per parasitized nest.Of the total host eggs,54%were damaged.During the incubation stage,20 nests(47%)were abandoned because of egg punctures by shiny cowbirds females.Only two parasitic fledglings were recorded,while the remaining nestlings either died from starvation(n=12)or predation(n=3).Foster parents abandoned parasitic nestlings between 5 and 10 days old.Our findings demonstrate that the shiny cowbird has very low rates of fledging success when parasitizing black-backed water tyrant.Also,parasitism had a high reproductive cost in the black-backed water tyrant because a very low proportion(7%)of the parasitized nests(n=43)were successful.展开更多
The interactions between avian brood parasites and their hosts provide an informative and easy-to-handle system for studying coevolution.Avian brood parasitism reduces the reproductive success of hosts,and thus,hosts ...The interactions between avian brood parasites and their hosts provide an informative and easy-to-handle system for studying coevolution.Avian brood parasitism reduces the reproductive success of hosts,and thus,hosts have evolved anti-parasitic strategies,such as rejecting parasitic eggs and adopting aggressive nest defense strategies,to avoid the cost brought on by brood parasitism.To test whether host anti-parasitic strategies are adjusted with the risk of being parasitized when the breeding seasons of brood parasites and hosts are not synchronous,we conducted a field experiment assessing nest defense and egg recognition behaviors of the Isabelline Shrike(Lanius isabellinus),a host of the Common Cuckoo(Cuculus canorus).In the local area,the host Isabelline Shrike begins to breed in April,whereas the summer migratory Common Cuckoo migrates to the local area in May and begins to lay parasitic eggs.Results showed that nest defense behaviors of the Isabelline Shrike increases significantly after cuckoo arrival,showing higher aggressiveness to cuckoo dummies,with no significant difference in attack rates among cuckoo,sparrowhawk and dove dummies,but their egg rejection did not change significantly.These results imply that Isabelline Shrikes may adjust their nest defense behavior,but not egg rejection behavior,with seasonality.展开更多
基金supported by the National Natural Science Foundation of China(31071938 and 31272328 to WL,31101646 and 31260514 to CY)Program for New Century Excellent Talents in University(NCET-10-0111 to WL)the United Foundation for Natural Science of National Natural Science Foundation of China and People's Government of Guangdong Province(U0833005 to ZZ)
文摘Rates of brood parasitism vary extensively among host species and populations of a single host species. In this study, we documented and compared parasitism rates of two sympatric hosts, the Oriental Reed Warbler （Acrocephalus orientalis） and the Reed Parrotbill （Paradoxornis heudei）, in three populations in China. We found that the Common Cuckoo （Cuculus canorus） is the only parasite using both the Oriental Reed Warbler and Reed Parrotbill as hosts, with a parasitism rate of 22.4%-34.3% and 0%-4.6%, respectively. The multiple parasitism rates were positively correlated with local parasitism rates across three geographic populations of Oriental Reed Warbler, which implies that higher pressure of parasitism lead to higher multiple parasitism rate. Furthermore, only one phenotype of cuckoo eggs was found in the nests of these two host species. Our results lead to two conclusions： （1） The Oriental Reed Warbler should be considered the major host of Common Cuckoo in our study sites; and （2） obligate parasitism on Oriental Reed Warbler by Common Cuckoo is specialized but flexible to some extent, i.e., using Reed Parrotbill as a secondary host. Further studies focusing on egg recognition and rejection behaviour of these two host species should be conducted to test our predictions.
基金supported by the National Natural Science Foundation of China (Nos.31301888 and 31672316 to DL)the General Scientific Research Project of the Education Department of Liaoning Province (L2015196 to DL)the Open Fund of the Ministry of Education Key Laboratory for Biodiversity Sciences and Ecological Engineering, Beijing Normal University (K1401 to DL)
文摘Background: The success of cuckoo parasitism is thought to depend largely on the extent of egg matching between cuckoo and host eggs, since poor-matching cuckoo egg would lead to more frequent egg rejection by the host. In this study, we investigated how egg-spot matching between the Common Cuckoo(Cuculus canorus) and its host, the Oriental Reed Warbler(Acrocephalus orientalis) is affected by the local parasitism rate, nest availability in breeding synchronization and egg rejection.Methods: We used the paired design of parasitized and their nearest non-parasitized nests where breeding occurred simultaneously to compare egg-spot matching. The image analysis was used to compare four eggshell pattern variables, namely spot size, density, coverage on the different areas of egg surface, and the distribution on the whole egg surface. Egg recognition experiments were conducted to test the effect of egg spots on egg rejection by the host.Results: Our results show that much better matching in almost all spot parameters tested on the side of the egg and the spot distribution on the whole egg occurred in parasitized nests than in non-parasitized nests. Matching of spot density between cuckoo and host eggs in parasitized nests increased with the synchronization between temporal availability of nests and the egg-laying period of female cuckoos. Egg recognition experiments in which the warbler eggs were deliberately painted with extra spots led to a significantly higher egg rejection rate(78.3%) than of unpainted eggs.Conclusion: Our data suggest that both the high temporal encounter rate between cuckoo and warbler nests as well as the high egg rejection ability of the host are important factors for egg-spot matching of the cuckoos.
基金funded by the National Natural Science Foundation of China (31071665)the Special Fund for Agro-Scientific Research in the Public Interest, China (200903040)
文摘Ten populations of Radopholus similis from different ornamental hosts were tested for their parasitism and pathogenicity to water spinach （Ipomoea aquatic）, malabar spinach （Basella rubra）, and squash （Cucurbita moschata） in pots. The re- sults showed all three plants were new hosts of R. similis. Growth parameters of plants inoculated with nematodes were significantly lower than those of healthy control plants. All R. similis populations were pathogenic to the three plants, but pathogenicity differed among populations from different hosts. The same R. similis populations also showed different pathogenic effects in the three different plants. RadN5 population from Anthurium andraeanum had the highest pathoge- nicity to the three studied plants. RadN1 from A. andraeanum had the lowest pathogenicity to squash and RadN7 from Chrysalidocarpus lutesens had the lowest pathogenicity to water spinach and malabar spinach. R. similis is usually associated with root tissues, but here we report that it could be found to move and feed in the stem bases of all three studied plants. Sequence and phylogenetic analyses of DNA markers of the 18S rRNA, 28S rRNA, ITS rRNA, and mitochondrial DNA gene sequences of ten R. similis populations revealed significant genetic diversity. RadN5 and RadN6 populations from anthurium showed a close genetic relationship and could be distinguished from other populations by PCR-RFLP. At the same time, RadN5 and RadN6 populations were the most pathogenic to three studied plants. These results confirm the existence of large biological variability and molecular diversity among R. similis populations from the same or different hosts, and these characteristics are related to pathogenic variability.
基金provided by a BEARS Grant and a Neag Undergraduate Research Grant from Kutztown University
文摘Background:Red-winged Blackbirds(Agelaius phoeniceus),hereafter red-wings,are much less frequently parasitized by Brown-headed Cowbirds(Molothrus ater)in eastern North America than in central North America and had not been recorded as hosts in our study area in southeastern Pennsylvania.Although hosts of Old World cuckoos(Cuculidae)often show geographic variation in egg rejection behavior,cowbird hosts typically exhibit uniform responses of all acceptance or all rejection of cowbird eggs.Thus,geographic variation in cowbird parasitism frequencies might reflect a different behavioral response to parasitism by hosts where only some populations reject parasitism.In this study,we tested whether egg rejection behavior may explain the lack of parasitism observed in our eastern red-wing population,which may provide insight into low parasitism levels across eastern North America.Methods:We parasitized red-wing nests with model cowbird eggs to determine their response to parasitism.Nests were tested across three nest stages and compared to control nests with no manipulations.Because rejection differed significantly by stage,we compared responses separately for each nest stage.We also monitored other songbird nests to identify parasitism frequencies on all potential hosts.Results:Red-wings showed significantly more rejections during the building stage,but not for the laying and incubation stages.Rejections during nest building involved mostly egg burials,which likely represent a continuation of the nest building process rather than true rejection of the cowbird egg.Excluding these responses,red-wings rejected 15%of cowbird eggs,which is similar to rejection levels from other studies and populations.The overall parasitism frequency on 11 species surveyed in our study area was only 7.4%.Conclusions:Egg rejection behavior does not explain the lack of parasitism on red-wings in our eastern population.Alternatively,we suggest that cowbird preference for other hosts and the low abundance of cowbirds in the east might explain the lack of parasitism.Future research should also explore cowbird and host density and the makeup of the host community to explain the low levels of parasitism on red-wings across eastern North America because egg rejection alone is unlikely to explain this broad geographic trend.
基金supported by a grant through‘Quota Scheme’at Norwegian University of Science and Technology(NTNU)
文摘The Plaintive Cuckoo(Cacomantis merulinus) is a widespread brood parasite in Asia, but no data on host species utilization in Bangladesh exist. By searching for nests of all possible host species of the Plaintive Cuckoo at Jahangirnagar university campus, north of Dhaka, we were able to determine which hosts were used in this area. We found that the Common Tailorbird(Orthotomus sutorius) was the only potential host used by Plaintive Cuckoos, and parasitism rate was rather high(31.3 %, n = 16). However, both host and cuckoo breeding success was poor(0 %, n = 16) due to frequent nest predation. Details on host and cuckoo egg appearance are provided. Our findings indicate that Common Tailorbirds are common hosts of the Plaintive Cuckoo in Central Bangladesh.
基金supported by the bilateral project of the Japan Society for the Promotion of Science (JSPS)the Hungarian Academy of Sciences to F.T. and C.M. 2003-2005+1 种基金by the Hungarian Scienti c Research Fund (OTKAgrant No.T35015,48397 and 83217) to C.M. e Duna-Ipoly and Kiskunság National Parks provided permissions for research
文摘Common Cuckoos(Cuculus canorus) parasitize nests of small passerines.e Cuckoo chicks cause the death of their nest-mates when evicting eggs or nestlings from the nests;consequently,hosts su er from a high loss of reproduction.Host adaptations against parasitism,e.g.,by egg discrimination behavior,and cuckoo counter-adaptations to hosts,e.g.,by mimetic eggs,are often regarded as a result of the arms race between the two interacting species.In Hungary Great Reed Warblers(Acrocephalus arundinaceus) are the main hosts of cuckoos,su ering from heavy parasitism(ca.40-65%).e Oriental Reed Warbler(A.orientalis),formerly a subspecies of the Great Reed Warbler(A.a.orientalis),is also a highly parasitized host in Japan(25-40%).We compared main characteristics of Cuckoo parasitism in these two distant areas from the Western and Eastern Palearctic by comparing cuckoo egg mimicry.We measured color characteristics of host and parasitic eggs by spectrophotometer.Visual modeling revealed lower chromatic distances between Cuckoo and host eggs in Hungary than in Japan,but high variation both in host and Cuckoo eggs may cause matching problems in Hungary.Achromatic(brightness) di erence between host and Cuckoo eggs were lower in Japan than in Hungary,and it proved to be the most important factor a ecting egg rejection.Hosts rejected Cuckoo eggs at similar frequencies(37% and 35% in Hungary and Japan,respectively).Host adaptation,i.e.,egg rejection behavior,seems to be preceding Cuckoo counter-adaptations to hosts in Japan.We suggest that the Cuckoo-Great/Oriental Reed Warbler relationships developed in alternative ways in Japan and Hungary,and they represent di erent stages of their arms race.
基金Supported by the Chinese Academy of Sciences Research Fellowship for International Young Researchers to M Rajkumar hosted by J Sun,and the Knowledge Innovation Program of Chinese Academy of Sciences(Nos.KZCX2-YW-QN-205 and KZCX2-YW-213-2)
文摘A double parasitism(isopod Cymothoidae and copepod Pennellidae) on black-barred halfbeak fish,Hemiramphus far,was recorded from Pazhayar coastal waters(southeast coast of India) during September 2008.This is the first report from this region and the infection is discussed in relation to environmental and biological parameters.
基金This study was supported by the Education Department of Hainan Province(HnjgY2022-12)Hainan Provincial Natural Science Foundation of China(320CXTD437 and 2019RC189)+1 种基金the National Natural Science Foundation of China(32260127 and 31672303)to CYthe Hainan Provincial Innovative Research Program for Graduates(Qhyb2021-55)to XC.
文摘Living and/or non-living animal models are often used as stimuli to observe the behavioral responses of the target animals.In the past,parasites,predators,and harmless controls have been used to test host anti-parasitism defense behavior,and their taxidermy specimens have been widely used as a set of standard methods for the study of avian brood parasitism.In recent years,with the rapid development of 3D-printing technology,3D-printed bird models are expected to be applied as a standard method in the study of avian brood parasitism.To evaluate the use of 3D-printed models,this study tests the reaction of Oriental Reed Warbler(Acrocephalus orientalis)towards predators,parasites,or controls,and compares the reaction among different nest intruders and between taxidermy specimens and 3D-printed animal models.It was found that the Oriental Reed Warbler responded most aggressively to the parasite,followed by predator,and finally the control;the results were consistent between the reaction to taxidermy specimens and 3D-printed animal models,indicating that 3D-printed models could serve as a substitute for taxidermy specimens.We propose a series of advantages of using 3D-printed models and suggest them to be a standard method for widespread use in future studies of avian brood parasitism.
文摘The effects of parasitic capacitance in induction motor system are unnoticed when it is fed from the AC line, but they are obvious when supplied directly from a PWM inverter. Consequently, many parasitic problems occur, such as motor to earth leakage current, bearing current, incoming line current distortion and uneven distribution of electrical stresses along the winding. On the basis of the uniform transmission line principle, a complete equivalent circuit of the PWM inverter fed motor system is presented, based on which all the capacitive parasitic problems mentioned above are analyzed and simulated by means of PSPICE. All the results are consistent with the existing ones.
文摘Introduction: Intestinal parasitism has been a challenge to overcome for the Mexican deworming campaign and this study determined the prevalence of these infections in schoolchildren treated with albendazole in Northwestern Mexico. Methods: Study sites in marginal conditions, with gastrointestinal infections and albendazole intervention were selected. The Faust and Kato Katz techniques were used to identify the parasites spp. and the NCSS software was used for statistical analysis. Results: A total of 450, 389 and 364 schoolchildren participated in 2005, 2006, and 2007 respectively during this study. The mean age was 7.9 (±1.3). The estimated prevalences were of 42%, 30% and 37% for protozoa infections, and 11%, 12% and 11% for helminth infections in 2005, 2006 and 2007 respectively. Conclusion: The education strategies should be integrated into the Mexican deworming campaign.
文摘The reniform nematode (RN), Rotylenchulus reniformis, is an agriculturally important pest with a broad host range that results in a large economic impact in tropical, subtropical and in warm temperate zones. In an initial effort to understand the transcriptome and gene expression in RN, we present EST results that reveal numerous putative parasitism-related genes some of which play roles in plant cell wall modification. The characterized contigs included 8362 (40.6%) matches to unique proteins. Coding contigs predicted were 10,656 (51.7%) or 3079 (14.9%), that was similar to those identified in Brugia malayi and Caenorhabditis elegans as reference organisms respectively. Specific transcripts studied in more detail include putative plant parasitism genes, prominent among them were several plant cell wall modification genes. Contigs matching 14 parasitism genes found in sedentary endoparasitic nematodes included expansins, hexosaminidase, glycosyl hydrolases family, 14-3-3 protein, xylanases, glutathione peroxidase, pectate lyase, β-1,4-endoglucanase, major sperm protein, aminopeptidase, c-type lectin, chitin synthase, FMR famide-like peptide, and calreticulin. These genes function in suppression of host defenses and development of feeding sites.
基金supported by an Australian Research Council Australian Research Fellowship
文摘The strategies used by parasitic cuckoos to fool their hosts have intrigued naturalists and ornithologists for centuries. Here I review some of the tricks used by Australian parasitic cuckoos to increase host nest availability, access host nests, and fool their hosts into accepting their eggs and chicks. Some of these strategies are widely used by cuckoo species around the world, but other traits, such as cryptic eggs and mimetic chicks, appear to be largely restricted to the Australasian cuckoos. Generalist cuckoos face greater challenges than specialists if they must fool multiple host species, and this provides a possible explanation for why different species of cuckoos have evolved different strategies for host deception.
文摘Unlike most brood parasites, several species of cowbird (Molothrus) are generalists that parasitize multiple host species across their range and within the same communities; likewise, there is little evidence that individuals within a population specialize on host species. This situation has variously been attributed to the recency of cowbird evolution (the 'evolutionary lag' hypothesis) or to hidden costs of rejection by hosts (the 'equilibrium' hypothesis). Both hypotheses have some support as cowbirds are indeed a relatively young clade compared with more specialized cuckoos and cowbirds are capable of sophisticated behaviors such as retaliation against rejection ('mafia' behaviors) that would select for acceptance of cowbird eggs. Nevertheless, many species in the Americas have evolved specialized defenses against cowbird parasitism, almost all of which live in more open habitats (e. g., grasslands, shrublands, riparian strips), which indicates that coevolutionary processes can operate in ways that select for host defenses in spite of cowbird counterdefenses. We propose that the structure of landscapes in North America may explain why forest-nesting birds lack defenses against parasitism and reinforce the long-term maintenance of generalized brood parasitism in cowbirds. Because cowbirds require open habitats in which to feed, they are rare or absent in large forest tracts, which dominate much of the forest cover of the Americas. These tracts act as 'source habitats' that produce surplus young that recolonize populations in smaller, fragmented forest patches in which rates of both cowbird parasitism and nest predation are very high ('sink' habitats). Evolution of antiparasite adaptations would be very slow in this situation because most hosts are produced in areas where there is little or no cowbird parasitism. In addition, the interplay of host breeding dispersal, source-sink metapopulation dynamics, and fragmented forest habitat could further deter the evolution of host defenses against parasitism. Therefore, as long as large forest tracts remain widespread in North America, most forest birds will likely continue to lack defenses against cowbird parasitism, guaranteeing a steady supply of na ve hosts in forest habitats, even in fragmented landscapes. This situation will, in turn, favor host generalist cowbirds that actively avoid more open habitats in favor of parasitizing forest bird communities. These forest communities may also act as source populations for cowbirds, which might pump surplus generalist cowbirds into more open habitats further slowing the coevolutionary process. As long as large forest tracts are a common part of the landscape, generalist parasitism may persist indefinitely.
文摘正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments
文摘Tea tortrix, Homona coffearia Nietner (Lepidoptera: Tortricidae), is a seasonal pest of tea in Sri Lanka. Though it is active in dry weather, it is observed that populations do occur in wet weather causing serious damage to tea. The parasite, Macrocentrus homonae Nixon (Hymenoptera: Braconidae), controls the tortrix populations, but the efficiency of Macrocentrus has been reduced on account of hyperparasites in recent times. Level of hyperparasitism was studied in some tea tortrix prone areas in the up country region to study how this affected the tortrix populations during wet weather. The hyperparasitism varied during the study period of which average values observed ranged from 35% to 52% in the plantations studied. A negative linear relationship was observed between the average number of parasite cocoons in a cocoon mass and the percentage hyperparasitism. Three generations of tortrix were evident during the study period of May to November 2005. It is observed that tortrix populations do occur in dry and wet weather, and that hyperparasitism has been identified as the major cause affecting the efficient control of tortrix by the parasite. Possibilities of tea tortrix control in wet weather are discussed.
文摘正Invited participants on the 3rd International Symposium on Avian Brood Parasitism, sponsored by Hainan Normal University (HNU), China, Norwegian University of Science and Technology (NTNU), Norway, the Research Council of Norway, and China Ornithological Society (COS).
文摘Objective:To ascertain the level of intestinal parasites vis-a-vis the quality of housing and water supply,and sanitary conditions among the people of Kuraje village in Zamfara state. Methods:The study was cross sectional in nature.Individual households were selected using systematic random sampling methods and pre-tested questionnaires were administered to all the members of each household.Stool samples were collected and processed using standard laboratory procedures.Housing conditions,sources of water and sanitary conditions of the households were also inspected.Results were analysed using Epi Info 2006 model.Results: The prevalence of intestinal parasites was 67.0%(347/519).72.3%(251/347),17.0%(59/347),and 10.7%(37/347) had one,two and three or more parasites,respectively.The associated factors with intestinal parasites were poor housing and sanitary conditions,lack of potable water and illiteracy.The commonest parasites encountered were hookworm(22.0%),Ascaris lumbricoides (18.5%),and Strongyloides stercoralis(15.6%) while the least common was Enterobius vermicularis (1.6%).Others were Giardia lamblia(5.7%),Hymenolepsis nana(5.0%),Trichuris trichiura(8.8%), Entamoeba histolytica(14.4%) and Schistosoma mansoni(8.4%).Conclusions:The infection rate of intestinal parasites in Kuraje village is high.More efforts should be intensified towards improvement in sanitary and housing standards,supply of potable water and institution of a more comprehensive literacy programme for the people of the community.
文摘Captivity of wild animals and restriction of their movement can lead to stress, resulting in suppressed immune response and reduced disease resistance ability. Wild animals in zoological gardens can predominately affected by various gastro-intestinal parasites. This study was therefore, conducted to determine occurrence, identify types and assess seasonal variation of gastrointestinal parasites in captive animals at the Zoological garden of Haramaya University. The study involved a retrospective investigation of zoo records and fecal examinations. Twenty two fecal samples were collected in December, 2013 from all the animals in the garden and examined using concentration and fecal culture techniques. Sampling was repeated after four months in April, 2014 to assess seasonal variations of the parasites. The result from the retrospective study showed death of 21 animals in the last five years. Fecal examination confirmed presence of gastrointestinal parasites with an overall mean prevalence rate of 73.8%. A total of 9 parasite taxa were identified of which 6 (66.67%) and 4 (33.33%) were helminths and protozoa respectively. No Cestode and Trematode species were recovered. <i>Trichuris spp.</i>, <i>Toxocara spp.</i>, <i>Strongyloides spp.</i>, <i>Toxascaris leonine</i>, <i>Passalurus ambiguous</i> and <i>Ascaridia spp.</i> were the helminth parasites observed in the garden. <i>Entamoeba spp.</i>, <i>Isospora spp.</i> and <i>Eimeria spp.</i> were the protozoan parasites encountered. No remarkable seasonal variation in parasitic infection was noticed in the garden. The study revealed occurrence of gastrointestinal parasites in the zoological garden, most of which are zoonotic and hence future studies are needed to determine risks of cross-transmission.
文摘The shiny cowbird Molothrus bonariensis parasitizes many species with different life-history traits and has a detrimental effect on the survival of the progeny of the hosts.In response,hosts have developed numerous antiparasitic defenses.Here,we examined the effects of brood parasitism by shiny cowbird on the clutch and brood sizes(83 nests)in a small host,the black-backed water tyrant Fluvicola albiventer.We also studied whether the death of parasite nestlings was related to the care of the foster parents and whether the host had any antiparasitic defense against the shiny cowbird.Our results indicate that brood parasitism significantly decreased the host hatching and fledging successes.The majority of nest failures(57%)were caused by brood parasitism.Shiny cowbird parasitism occurred in 52%of nests and the intensity of parasitism was 1.23±0.53 eggs per parasitized nest.Of the total host eggs,54%were damaged.During the incubation stage,20 nests(47%)were abandoned because of egg punctures by shiny cowbirds females.Only two parasitic fledglings were recorded,while the remaining nestlings either died from starvation(n=12)or predation(n=3).Foster parents abandoned parasitic nestlings between 5 and 10 days old.Our findings demonstrate that the shiny cowbird has very low rates of fledging success when parasitizing black-backed water tyrant.Also,parasitism had a high reproductive cost in the black-backed water tyrant because a very low proportion(7%)of the parasitized nests(n=43)were successful.
基金funded by the National Natural Science Foundation of China (Nos. 31970427 and 32270526 to WL)。
文摘The interactions between avian brood parasites and their hosts provide an informative and easy-to-handle system for studying coevolution.Avian brood parasitism reduces the reproductive success of hosts,and thus,hosts have evolved anti-parasitic strategies,such as rejecting parasitic eggs and adopting aggressive nest defense strategies,to avoid the cost brought on by brood parasitism.To test whether host anti-parasitic strategies are adjusted with the risk of being parasitized when the breeding seasons of brood parasites and hosts are not synchronous,we conducted a field experiment assessing nest defense and egg recognition behaviors of the Isabelline Shrike(Lanius isabellinus),a host of the Common Cuckoo(Cuculus canorus).In the local area,the host Isabelline Shrike begins to breed in April,whereas the summer migratory Common Cuckoo migrates to the local area in May and begins to lay parasitic eggs.Results showed that nest defense behaviors of the Isabelline Shrike increases significantly after cuckoo arrival,showing higher aggressiveness to cuckoo dummies,with no significant difference in attack rates among cuckoo,sparrowhawk and dove dummies,but their egg rejection did not change significantly.These results imply that Isabelline Shrikes may adjust their nest defense behavior,but not egg rejection behavior,with seasonality.
