大杜鹃雌鸟鸣声的日节律

本文描述了三个地区大杜鹃(Cuculus canorus)雌鸟鸣声的日节律。通过在北京野鸭湖湿地公园(2017年5月7日至7月8日)、辽宁辽河口自然保护区(2018年6月28日至7月29日)和吉林大岗子林场(2018年5月17日至7月10日)分别布设自动录音机10台、10台和8台,连续记录繁殖季大杜鹃的鸣声。共录到2 777次大杜鹃雌鸟的鸣叫。其中,1 431次来自北京野鸭湖湿地公园,1 222次来自辽宁辽河口自然保护区,124次来自吉林大岗子林场。野鸭湖湿地公园和辽河口自然保护区的大杜鹃雌鸟在日出时段出现鸣叫的高峰,而大岗子林场的大杜鹃在日出和日落时段各有一个鸣叫的高峰。通过比较大杜鹃雌鸟鸣声的日节律和大杜鹃产卵时间的日节律,本研究认为在上述地区大杜鹃雌鸟鸣叫的功能更可能是宣示领域和吸引异性,而非恐吓宿主。本研究有助于进一步了解大杜鹃雌鸟鸣声的功能。     

Errors in egg-laying by female Common Cuckoo Cuculus canorus in nests of its common host

Dozens of studies have documented that brood parasites are well adapted to a brood parasitic lifestyle but not all parasitism events are successful. Co-evolution between brood parasites and their hosts is a dynamic process so it is reasonable to expect that a female brood parasite may commit errors during egg deposition by laying her eggs outside the laying period of the host, with consequent impacts on her fitness. Using an extensive dataset from a long-term study, we evaluated egg-laying patterns and errors related to the timing of egg-laying in the Common Cuckoo Cuculus canorus (hereafter ‘Cuckoo’). Specifically, we tested whether the Cuckoo avoids laying before or on the day of host clutch initiation to reduce the risk of rejection of parasitic eggs, whether laying errors will be more frequent in periods with a lack of active host nests, and whether the laying errors will be more frequent in periods with intense Cuckoo parasitism and a consequent lack of suitable host nests. We found that about one-third of Cuckoo eggs were laid on the host clutch initiation day or 1 day before, and the percentage of Cuckoo eggs laid decreased thereafter. Surprisingly, the probability of Cuckoo egg acceptance by the hosts was not affected by the egg-laying stage of the host clutch. Errors in the timing of egg-laying with fatal consequences (i.e. those precluding Cuckoo hatching because of laying in incubated or deserted clutches) were recorded in about 5% of cases. Only laying date of a Cuckoo egg had a significant effect on the probability of errors, which increased during the breeding season. This may be related to the higher number of deserted and incubated host nests at the site at the end of the breeding season. Errors in egg-laying may be attributed to young and inexperienced females but also impaired body condition or intraspecific competition may cause this behaviour. Future studies, which will test these possible explanations, will help to understand better the mechanism of co-evolutionary arms races and differences between host specialist and generalist brood parasites in various host–parasite systems.     

Post-fledging interactions between the Common Cuckoo Cuculus canorus and its cavity-nesting Common Redstart Phoenicurus phoenicurus host

Brood parasite–host interactions during the incubation and nestling stages have been well studied, but the post-fledging period remains virtually unknown. Using radiotracking, we provide the first detailed data on post-fledging interactions between the Common Cuckoo Cuculus canorus and its only regular cavity-nesting host, the Common Redstart Phoenicurus phoenicurus. Cuckoos raised alone (‘solitary’) fledged at higher mass, with higher wing and tarsus length and started to fly at a younger age than Cuckoos raised alongside young Redstarts (‘mixed’). However, a further 23 fledging and post-fledging parameters measured at five pre-determined times (fledging, first-flight, predation, starvation, independence) did not differ between solitary and mixed Cuckoos. In addition, none of the parameters measured during the post-fledging period (growth, dispersal distances, number of flights) differed between solitary and mixed Cuckoos. Redstart fledglings from non-parasitized broods (‘solitary’) showed generally similar fledging and post-fledging parameters to fledglings reared alongside a Cuckoo (‘mixed’). Surprisingly, there were no significant differences in post-fledging predation rate, starvation or overall survival rates between mixed and solitary Cuckoos or mixed and solitary Redstarts. Thus, during the post-fledging period, mixed Cuckoo fledglings successfully compensated for the poorer performance experienced during the nestling stage whereas mixed and solitary Redstarts did not differ in any measured parameters. This suggests that the regular occurrence of mixed broods in this host–parasite system – which is unique among the many Cuckoo hosts – is evolutionarily stable for both hosts and parasites.     

大杜鹃对家燕的巢寄生

了解杜鹃(Cuculus spp.)对不同宿主鸟类的巢寄生,是研究杜鹃与其宿主之间协同进化的重要基础资料。大杜鹃(Cuculus canorus)和家燕(Hirundo rustica)分布遍及全国,且为同域分布,但两者之间的寄生现象尚未有过系统调查。2012年和2014年4~8月,对繁殖于吉林市昌邑区桦皮厂镇(34°58′44.18″N,126°13′26.83″E,海拔184 m)和海南岛的家燕种群进行调查,结果表明,吉林市昌邑区桦皮厂镇家燕种群的寄生率为2.4%(1/42),而在海南岛所调查的1 719个家燕巢未发现杜鹃寄生现象。同时在网络上搜集家燕巢寄生的报道案例,共记录到13巢家燕被大杜鹃寄生繁殖,均发生在北方的家燕种群。     

Breeding ground correlates of the distribution and decline of the Common Cuckoo Cuculus canorus at two spatial scales

Many migratory bird species are undergoing population declines as a result of potentially multiple, interacting mechanisms. Understanding the environmental associations of spatial variation in population change can help tease out the likely mechanisms involved. Common Cuckoo Cuculus canorus populations have declined by 69% in England but increased by 33% in Scotland. The declines have mainly occurred in lowland agricultural landscapes, but their mechanisms are unknown. At both the local scale within the county of Devon (SE England) and at the national (UK) scale, we analysed the breeding season distribution of Cuckoos in relation to habitat variation, the abundance of host species and the abundance of moth species whose caterpillars are a key food of adult Cuckoos. At the local scale, we found that Cuckoos were more likely to be detected in areas with more semi‐natural habitat, more Meadow Pipits Anthus pratensis (but fewer Dunnocks Prunella modularis) and where, later in the summer, higher numbers of moths were captured whose larvae are Cuckoo prey. Nationally, Cuckoos have become more associated with upland heath characterized by the presence of Meadow Pipit hosts, and with wetland habitats occupied by Eurasian Reed Warbler Acrocephalus scirpaceus hosts. The core distribution of Cuckoos has shifted from south to north within the UK. By the end of 2009, the abundance of macro‐moth species identified as prey had also declined four times faster than that of species not known to be taken by Cuckoos. The abundance of these moths has shown the sharpest declines in grassland, arable and woodland habitats and has increased in semi‐natural habitats (heaths and rough grassland). Our study suggests that Cuckoos are likely to remain a very scarce bird in lowland agricultural landscapes without large‐scale changes in agricultural practices.     

The importance of nest‐site and habitat in egg recognition ability of potential hosts of the Common Cuckoo Cuculus canorus

The intensity of selection exerted by brood parasites on their hosts depends on the proportion of nests that are parasitized and the fitness costs of parasitism. Nest detection by brood parasites influences the probability of parasitism, and we propose that the difficulty faced by brood parasites of finding nests on the ground may make ground‐nesting species subject to lower levels of parasitism, causing a reduction in levels of defence compared with species breeding in shrubs, trees and elsewhere above the ground. We tested the prediction that the rejection rate of Common Cuckoo Cuculus canorus eggs by hosts is inversely related to the frequency with which they build nests on the ground, both at local and at continental scales. First, we used estimates of the rejection rate of non‐mimetic model eggs experimentally introduced into the nests of 26 potential host species breeding in the Sierra Nevada Mountains of southern Spain. Most species tested in the Sierra Nevada showed high rejection rates of both mimetic and non‐mimetic eggs, whereas the European Robin Erithacus rubecula, with a low rejection rate, was the only species that was regularly parasitized. At the continental scale we used all available published information on rejection rates of non‐mimetic models by European hosts of the Common Cuckoo. The frequency of ground‐nesting explained interspecific variation in rejection rate of non‐mimetic model eggs both for the species tested in the Sierra Nevada and for all European hosts after controlling for all other life‐history variables known to affect rejection rates. An effect of the abundance of trees in a particular habitat, previously shown to affect parasitism by the Common Cuckoo, was only apparent from analyses of continental‐scale data and not from the Sierra Nevada mountains, suggesting that particular properties of mountainous areas affect Common Cuckoo parasitism. Ground‐nesting species showed lower rejection rates than species breeding in bushes or trees. These results suggest that species nesting on the ground may have suffered lower parasitism pressures in their historical coevolutionary interactions with the Common Cuckoo.     

Spring arrival patterns of the Cuckoo Cuculus canorus,Nightingale Luscinia megarhynchos and Spotted Flycatcher Musciapa striata in Britain

Data on the arrival dates of Cuckoo, Nightingale and Spotted Flycatcher published in the Royal Meteorological Society phenological reports are presented. From these records, contour maps showing the pattern of progression through Britain were produced for each species. Of the three species, the Cuckoo arrived earliest and progressed the slowest from south to north; it entered Britain by the southeast. The Nightingale arrived later than the Cuckoo and progressed along a southeast to northwest axis. The Spotted Flycatcher was the last to arrive, but progressed with the greatest speed from south to north. Arrival dates of all three species were influenced by the temperature in southern Europe in the month preceding arrival in Britain and by the difference between these temperatures in southern Europe and those a month later in France or Britain. The diminishing population levels of Nightingale may have had a masking effect on its arrival dates. Although mean arrival dates for the three species were strongly influenced by temperature, long-term trend effects should be interpreted with caution as other factors also influence mean arrival dates.     

European Cuckoo Cuculus canorus parasitism and host's rejection behaviour in a heavily parasitized Great Reed Warbler Acrocephalus arundinaceus population

An unusually high frequency (64%) of European Cuckoo Cuculus canorus parasitism was found in Great Reed Warbler Acrocephalus arundinaceus clutches in central Hungary. Sixty-four per cent of the parasitized clutches contained one Cuckoo egg, 23% contained two, 10% had three and 3% had four. This means that 58% of the Cuckoo eggs were found in multiply parasitized clutches. In multiple parasitism the laying second Cuckoo removed an egg from the clutch randomly, so preferred neither the host eggs, nor the concurrent Cuckoo egg. Host response towards the parasitic eggs showed 66% acceptance, 12% ejection, 20% desertion and 2% egg burial. We found great variation in both the host and the parasitic egg colour and pattern. This reduces the chance that the parasitic egg's appearance matched that of the hosts' but, in spite of this, almost perfect mimesis was found in 28% of the Cuckoo eggs. Poorly mimetic Cuckoo eggs were more frequently rejected by Great Reed Warblers than parasite eggs that were very similar to the host eggs. This high level of mimicry sometimes makes it difficult for the observer to identify the parasitic egg, especially when it is similar in size to the host eggs. It is also difficult for the host, as shown by the relatively high recognition error and ejection cost.     

中国大杜鹃的鸣声

一直以来认为广布欧洲大陆和亚洲大陆的大杜鹃 ,其鸣声在地区之间无差异 ,而分布在亚洲的大杜鹃的鸣声至今未有系统的研究报道。本文以分布在中国北部的大杜鹃指名亚种和新疆亚种的广告鸣叫为主要研究对象 ,将其与在四川和云南省分布的大杜鹃华西亚种以及分布在朝鲜、日本、俄罗斯和英格兰的大杜鹃指名亚种的广告鸣叫进行了初步比较。在中国分布的大杜鹃有五种鸣叫类型。中国所有采集地大杜鹃的广告鸣叫都由两个音节组成 ,并且与英国分布种群的广告鸣叫很相似。各地大杜鹃的领域鸣唱呈现出个体质的高度保守性和数量性状的明显差异     

Avian brood parasitism in a Mediterranean region: hosts and habitat preferences of Common Cuckoos Cuculus canorus

Capsule Cuckoos in Italy support the ‘host preference’ hypothesis.

Aims To identify the species parasitized in a Mediterranean area, in Italy; to quantify the frequency of parasitism on each host species; and to determine whether some species and/or habitat types are parasitized more than expected from a homogeneous distribution.

Methods Nest records dating from 1865 were compiled from literature, nest card programmes, and personal communication with ornithologists working in the region. Comparisons of parasitism frequencies were made among and within habitats for all cuckoo hosts.

Results The most frequently parasitized hosts were Great Reed Warbler, European Robin, Marsh Warbler, Redstart, and Reed Warbler. The highest number of parasitized species was in anthropic areas (15 host species), whereas wetlands supported the highest number of parasitized nests (471).

Conclusion Cuckoos select a different suite of hosts in Italy from those in continental Europe, but this was not always explained on the basis of different geographical distribution. Results support the ‘host preference’ hypothesis. We suggest further analyses to avoid over‐ or underestimates of parasitism on each host species when parasite preferences are examined.     

Responses of breeding Reed Warblers Acrocephalus scirpaceus to mounts of Sparrowhawk Accipiter nisus, Cuckoo Cuculus canorus and Jay Garrulus glandarius

Mounts of a Cuckoo Cuculus canorus , a Sparrowhawk Accipiter nisus and a Jay Garrulus glandarius were presented at nests of Reed Warblers Acrocephalus scirpaceus at all breeding stages. Response strength could best be classified according to approach distance (to the mount) and vocalizations used. Warblers reacted much more aggressively to a mount on the nest than to one 3 m adjacent; they approached much more closely, were less likely to sing but often gave a frenzied-sounding rasp (which was never given to an adjacent mount). Reaction was more aggressive to a Cuckoo, which was often attacked, than to a Sparrowhawk, of which they were wary; response to a Jay was intermediate. Reaction was more aggressive after the clutch had been completed than before. After the brood had fledged, parents still responded strongly to the Jay and Sparrowhawk, but responded to the Cuckoo only briefly before ignoring it. These results are consistent with the Reproductive Value-Stimulus Value hypothesis. They also demonstrate that Reed Warblers can tell Cuckoos from Sparrowhawks, as can many non-host species. The close resemblance of these two species is often suggested to be mimicry of the Sparrowhawk by the Cuckoo but, if this is so, it is not successful. Alternatively, the similarity could be mimicry to reduce predation on the Cuckoos themselves, a chance resemblance, or due to similar selective forces acting on both species, as each would presumably benefit from reduced conspicuousness.     

Egg colour mimicry in the common cuckoo Cuculus canorus as revealed by modelling host retinal function

Some parasite cuckoo species lay eggs that, to the human eye, appear to mimic the appearance of the eggs of their favourite hosts, which hinders discrimination and removal of their eggs by host species. Hitherto, perception of cuckoo-host egg mimicry has been estimated based on human vision or spectrophotometry, which does not account for what the receivers' eye (i.e. hosts) actually discriminates. Using a discrimination model approach that reproduces host retinal functioning, and museum egg collections collected in the south of Finland, where at least six different races of the European cuckoo (Cuculus canorus) coexist, I first assess whether the colour design of cuckoo eggs of different races maximizes matching for two favourite avian hosts, viz. the redstart (Phoenicurus phoenicurus) and the pied wagtail (Motacilla alba). Second, I assess the role of nest luminosity on host perception of mimicry by the same two hosts. Phoenicurus-cuckoo eggs showed a better chromatic matching with the redstart-host eggs than other cuckoo races, and in most cases can not be discriminated. Sylvia-cuckoo eggs, however, showed better achromatic matching with redstart-host eggs than Phoenicurus-cuckoo eggs. Also, Motacilla-cuckoo eggs showed poorer chromatic and achromatic matching with pied wagtail-host eggs than Sylvia-cuckoo eggs. Nest luminosity affected chromatic and achromatic differences between cuckoo and host eggs, although only minimally affected the proportion of cuckoo eggs discriminated by chromatic signals. These results reveal that cuckoo races as assessed by humans do not entirely match with host perception of matching and that achromatic mechanisms could play a main role in the discrimination of cuckoo eggs at low-light levels.     

A comparative study of host selection in the European cuckoo Cuculus canorus

Certain kinds of hosts are commonly regarded as being more suitable than other for rearing European cuckoos (Cuculus canorus) – insectivores that lay small eggs and have open, shallow nests – although empirical tests of cuckoo host selection are lacking. We analysed host use by the European cuckoo in 72 British passerines that are potential hosts and for which there was information available on life-history variables and variables related to cuckoo-host coevolution, such as rate of parasitism, rejection rate of non-mimetic model eggs and degree of cuckoo-egg mimicry of host eggs. The relative population size of the host species affected parasitism rate most strongly, followed by relatively short duration of the nestling period, and the kind of nest, with cuckoos selecting open-nesting hosts. However, the effect of the nestling period could be related to host body size and the kind of nest used, because hole-nesting species normally have longer nestling periods than open-nesters. We re-analysed the data excluding hole nesters and corvid species (species with larger body mass), but the results remained identical. The European cuckoo may benefit from selecting hosts with short nestling periods because such hosts provide food for their nestlings at a very high rate. When only those species known as cuckoo hosts were analysed, the variable that best accounted for the parasitism rate was duration of the breeding season. Therefore, availability of potential hosts in both time and space is important for cuckoos in selecting hosts. Received: 16 July 1998 / Accepted: 27 October 1998     

Common cuckoo Cuculus canorus parasitism,antiparasite defence and gene flow in closely located populations of great reed warblers Acrocephalus arundinaceus

In Hungary an unusually high rate of parasitism on the great reed warbler Acrocephalus arundinaceus by the common cuckoo Cuculus canorus has been maintained for at least the last one hundred years. We evaluated parasitism rate, antiparasite defence and genetic differentiation among Hungarian great reed warblers at three sites located 40–130 km from each other, where hosts suffered from a high (41–68%), moderate (11%), and almost no (<1%) parasitism. We were especially interested in whether the level of antiparasite defence was related to the local parasitism rate, and, if not, to understand why. There was no difference among the three sites in the responses to experimental parasitism by non‐mimetic model cuckoo eggs (rejection rate 71–82%), which can be explained by strong gene flow between populations: there was low level of philopatry and no genetic differentiation in the region. Reproductive success of the host in the heavily parasitised site was about 54% of that in the unparasitised site, indicating that long‐term persistence of host populations in highly exploited areas depends on continuous immigration.