OBSERVATIONS ON THE BREEDING OF THE PIED CROW AND GREAT SPOTTED CUCKOO IN NORTHERN NIGERIA

Mundy. P. J. & Cook, A. W. 1977. Observations on the breeding of the Pied Crow and Great Spotted Cuckoo in northern Nigeria. Ostrich 48:72-84.

The breeding cycle of the Pied Crow Corvus albus was studied in 1971. The birds bred in the wet season and all of 23 pairs were single-brooded. They appeared to nest territorially, and mostly close to human habitations. Average clutch size was 4.8 eggs and the greenish eggs were either pale and lightly marked, or darker and heavily marked. The average incubation and fledging periods were 181/2 and 38 days respectively. Chicks hatched asynchronously. Five crow nests were found parasitised by the Great Spotted Cuckoo Clamator glandarius and it appeared that only one hen cuckoo was responsible. The cuckoo apparently did not remove, or even crack, host eggs. One instance of an adult cuckoo feeding a juvenile was seen. In terms of growth increments a cuckoo chick substituted for one-half a crow chick but developed faster and fledged in nearly one-half the time. The cuckoo reduced host breeding success practically to zero apparently by indirect means, which contrasts with its situation in Europe.     

SOME NOTES ON THE BREEDING BIOLOGY OF THE STRIPED CUCKOO

Steyn, P. 1973. Some notes on the breeding biology of the Striped Cuckoo. Ostrich 44: 163–169.

Information is presented on the breeding biology of the Striped Cuckoo, a species for which little authentic material exists. A number of cases of parasitism of the Arrow-marked Babbler are given. Pre-laying behaviour is similar to that of the Jacobin Cuckoo. The blue egg of the cuckoo may be distinguished on several minor points, but mainly because it is rounder and broader than those of the host species. The growth and development of a nestling is outlined up to its ninth day when it was killed by a snake. It was reared to this stage with three babbler chicks, probably because several babblers contribute to feeding the nestlings. The cuckoo gains weight very rapidly, and it is suggested that this is because of its brighter gape and more intense gaping response which ensure that it is fed preferentially. Anti-predator devices such as open-gaped lunges, jerking movements of the body and the exudation of a vile-smelling brown fluid are described. The nestling cuckoo's call is identical to that of the babblers. The juvenal may be fed by its foster parents For at least 36 days after leaving the nest.     

THE AMINO ACIDS OF SOME MISTLETOES AND THEIR HOSTS

The following mistletoes and their hosts were studied: Phoradendron serotinum (Raf.) M. C. Johnst. (P. flavescens [Pursh] Nutt. var. macrophyllum Engelm.) on Juglans hindsii Jeps. (California black walnut), Arceuthobium campylopodum Engelmn. f. abietinum (Engelm.) Gill on Abies concolor (Gord. and Glend.) Lindl. (white fir) and A. magnifica A. Murr (red fir), Arceuthobium campylopodum Engelm. f. campylopodum (Engelm.) Gill on Pinus sabiniana Dougl. (Digger pine), and Amyema pendula (Spleng) Tiegh. on Eucalyptus macrorhyncha F. Muell. ex Benth. (stringybark). With the exception of the Amyema leaves, the mistletoes are richer in free and bound amino acids than their hosts; moreover, their amino acid composition closely resembles that of their hosts. Nevertheless, there is no satisfactory evidence that mistletoe specificity depends on the amino acid composition of the hosts. Some mistletoes contain γ-aminobutyric acid and asparagine, not found in all hosts. All the above mistletoes but no hosts contain free hydroxyproline. These results are discussed in relation to (1) the region in the mistletoes where hydroxyproline is formed and (2) the possibility of using certain amino acid analogs as selective poisons for mistletoes.     

EVOLUTION OF INCOMPATIBILITY-INDUCING MICROBES AND THEIR HOSTS

In many insect species, males infected with microbes related to Wolbachia pipientis are “incompatible” with uninfected females. Crosses between infected males and uninfected females produce significantly fewer adult progeny than the other three possible crosses. The incompatibility-inducing microbes are usually maternally transmitted. Thus, incompatibility tends to confer a reproductive advantage on infected females in polymorphic populations, allowing these infections to spread. This paper analyzes selection on parasite and host genes that affect such incompatibility systems. Selection among parasite variants does not act directly on the level of incompatibility with uninfected females. In fact, selection favors rare parasite variants that increase the production of infected progeny by infected mothers, even if these variants reduce incompatibility with uninfected females. However, productivity-reducing parasites that cause partial incompatibility with hosts harboring alternative variants can be favored once they become sufficiently abundant locally. Thus, they may spread spatially by a process analogous to the spread of underdominant chromosome rearrangements. The dynamics of modifier alleles in the host are more difficult to predict, because such alleles will occur in both infected and uninfected individuals. Nevertheless, the relative fecundity of infected females compared to uninfected females, the efficiency of maternal transmission and the mutual compatibility of infected individuals all tend to increase under within-population selection on both host and parasite genes. In addition, selection on host genes favors increased compatibility between infected males and uninfected females. Although vertical transmission tends to harmonize host and parasite evolution, competition among parasite variants will tend to maintain incompatibility.     

REED WARBLER HOSTS FINE‐TUNE THEIR DEFENSES TO TRACK THREE DECADES OF CUCKOO DECLINE

Interactions between avian hosts and brood parasites can provide a model for how animals adapt to a changing world. Reed warbler (Acrocephalus scirpaceus) hosts employ costly defenses to combat parasitism by common cuckoos (Cuculus canorus). During the past three decades cuckoos have declined markedly across England, reducing parasitism at our study site (Wicken Fen) from 24% of reed warbler nests in 1985 to 1% in 2012. Here we show with experiments that host mobbing and egg rejection defenses have tracked this decline in local parasitism risk: the proportion of reed warbler pairs mobbing adult cuckoos (assessed by responses to cuckoo mounts and models) has declined from 90% to 38%, and the proportion rejecting nonmimetic cuckoo eggs (assessed by responses to model eggs) has declined from 61% to 11%. This is despite no change in response to other nest enemies or mimetic model eggs. Individual variation in both defenses is predicted by parasitism risk during the host's egg‐laying period. Furthermore, the response of our study population to temporal variation in parasitism risk can also explain spatial variation in egg rejection behavior in other populations across Europe. We suggest that spatial and temporal variation in parasitism risk has led to the evolution of plasticity in reed warbler defenses.     

COMPARATIVE POPULATION STRUCTURE AND GENE FLOW OF A BROOD PARASITE,THE GREAT SPOTTED CUCKOO (CLAMATOR GLANDARIUS), AND ITS PRIMARY HOST,THE MAGPIE (PICA PICA)

The amount of gene flow is an important determinant of population structure and therefore of central importance for understanding coevolutionary processes. We used microsatellite markers to estimate population structure and gene flow rates of the great spotted cuckoo (Clamator glandarius) and its main host in Europe, the magpie (Pica pica), in a number of populations (seven and 15, respectively) across their distribution range in Europe. The genetic analysis shows that there exists a pattern of isolation by distance in both species, although the cuckoo data are only indicative due to a small sample size. Gene flow seems to be extensive between nearby populations, higher for magpies than cuckoos, and especially high for magpie populations within the area of distribution of the great spotted cuckoo. There is no correlation between genetic distances between magpie populations and genetic distances between cuckoo populations. We discuss the implications of extensive gene flow between magpie populations in sympatry with cuckoos for the population dynamics of hosts, in particular for the occurrence of egg rejection behavior in host populations and how the different rates of migration for both species can affect the dynamics of coevolutionary processes.     

THE RESISTANCE OF INSECT PARASITOIDS TO THE DEFENCE REACTIONS OF THEIR HOSTS

Some of the following propositions are to be read as suggestions or hypotheses, supported by circumstantial or direct evidence, but not yet rigorously demonstrated. An estimate of the significance to be attached to each should be gathered from the body of the paper rather than from the following brief statements. 1.The problem is posed: how do endophagous parasitoids counteract the haemocytic defence reactions of their usual hosts? 2.It has been demonstrated that the egg and young first-instar larva of Nemeritis canescens have a coating on their surface which enables them to escape the attention of the haemocytes of their usual host, and to develop without exciting a defence reaction. The coating is applied to the egg before it is laid, and to the cuticle of the larva before it hatches. A little evidence suggests that some other ichneumon wasps of the subfamily Ophioninae may use this mechanism of resistance. 3.Older first-instar larvae, and the second and later instars, of many parasitoids, both hymenopterous and dipterous, probably overcome the haemocytic reaction of their host by rapid feeding, which depletes its blood both of cells and of nutrients, and so drains its resources that haematopoiesis is prevented and encapsulation becomes impossible. 4.The common habit of parasitoids of lingering in the first instar, before ingesting much food, while the host goes on developing to another stage or undergoes diapause, may enable the larva to retain a protective coating that would have become ineffective if it had grown. When at length the larva does feed and grow, the preceding mechanism (3) comes into play. 5.The teratocytes and pseudogerms formed by many species in several families of Hymenoptera absorb nutrients on a large scale from the blood of the host. They act quickly, as soon as the larva hatches. I suggest that by their attrition of the host's reserves of food, and its consequent debility, they prevent an effective haemocytic reaction to the young parasitoid. 6.Some dipterous and hymenopterous parasitoids first inhabit the intestine of their host, and do not penetrate the body cavity until they are ready to overwhelm the defence reactions by rapid and gross feeding. 7.Parasitoids that live temporarily inside an organ of the host may there acquire a coating which protects them from reaction by the blood cells. 8.Species of parasitoids that occupy an organ of the host for a long period, and develop inside it, escape a defence reaction because they live within the connective tissue covering the organ, to which the blood cells do not react. 9.Eggs of hymenopterous parasitoids laid within the embryos of their hosts may be treated by the embryonic blood cells as a developing organ, and become covered with connective tissue as those organs are. Thereafter they would not be recognized as foreign bodies. 10.Parasitoid eggs laid in the eggs or the young larvae of their host may be coated with host substances, or covered by connective tissue (9), before the blood of the host be comes capable of vigorousdefence reactions. They would there after escape recognition as foreign bodies. This may be the advantage of the habit of the so-called egg-larval parasitoids. 11.Reasons have been given by Schneider (1950) for his belief that the serosa of the ichneumon wasp Diplazon fissorius secretes something that locally inhibits the defence reactions of its hosts. The trophamnion and pseudoserosa of some parasitoid eggs may have this function. 12. Some parasitoids, especially second- and third-instar larvae of Tachinidae, physically repulse the haemocytes of their host, moulding them into a capsule that serves the maggot as a respiratory sheath.     

THE EVOLUTION OF PARASITISM IN THE RED ALGAE: MOLECULAR COMPARISONS OF ADELPHOPARASITES AND THEIR HOSTS1

In several groups of parasites including insect, flowering plant, fungal, and red algal parasites, morphological similarities of the parasites and their specific hosts have led to hypotheses that these parasites evolved from their hosts. But these conclusions have been criticized because the morphological features shared by parasite and host may be the result of convergent evolution. In this study, we examine the hypothesis, originally put forth by Setchell, that adelphoparasitic red algae, that is, parasitic red algae that are morphologically very similar to their hosts, evolved from their specific red algal hosts. Rather than comparing morphological features of parasites and hosts, small-subunit 18S nuclear ribosomal DNA and the internal transcribed spacer regions (ITSs) of the nuclear ribosomal repeat are compared for five parasites, their hosts, and related nonhosts from four red algal orders. These comparisons reveal that each of these adelphoparasites has evolved either directly from the host on which it is currently found, or it evolved from some other taxon that is closely related to the modern host. The parasites Gardneriella tuberifera, Rhodymeniocolax botryoides, and probably Gracilariophila oryzoides evolved from their respective hosts Sarcodiotheca gaudichaudii, Rhodymenia pacifica, and Gracilariopsis lemaneiformis, respectively. The parasite Faucheocolax attenuata evolved from either Fauchea laciniata or Fauchea fryeana and subsequently radiated onto the other host species. Presently this parasite is found on both hosts. Lastly, some parasitic genera such as Plocamiocolax are polyphyletic in their origins. A species of Plocamiocolax from an Antarctic Plocamium cartilagineum appears to have evolved from its host whereas the common Plocamiocolax pulvinata that occurs along the west coast of North America likely evolved from Plocamium violaceum and radiated secondarily onto its present day host, Plocamium cartilagineum.     

THE EVOLUTION OF PARASITISM IN RED ALGAE: CELLULAR INTERACTIONS OF ADELPHOPARASITES AND THEIR HOSTS1

In the initial stages of cell–cell interactions (spore germination and host penetration), the adelphoparasites Gardneriella tuberifera Kyl. and Gracilariophila oryzoides Setch. & Wilson form infection rhizoids that fuse directly with underlying host epidermal or cortical cells. In so doing, parasite nuclei and other organelles enter the cytoplasm of the host. The resulting heterokaryon may fuse with adjacent host cells either directly, via secondary pit connections, or by the dissolution or dislodgment of pit plugs from existing pit connections. The cell fusion events result in a heterokaryotic syncytium in which parasite nuclei replicate. In Gardneriella, formation of the syncytium induces surrounding host tissues to divide to form a photosynthetic callus. The internalized syncytium forms conjunctor and rhizoidal cells that fuse with host callus, eventually transforming the host callus into cells containing parasite nuclei. Gracilariophila does not induce surrounding host tissue to divide. Rather, division of the initial heterokaryotic tissue gives rise to the colorless mantle that protrudes from the host and forms reproductive structures. The heterokaryotic tissue also fuses with underlying host cells, thereby spreading parasite nuclei throughout adjacent host cells. In both these adelphoparasites, transformation of host cells by parasite nuclear invasion results in plastid dedifferentiation, an increase in mitochondria, autolysis of organelles, and accumulation of large amounts of floridean starch. The development and physiology of these parasites is similar to normal post-fertilization processes in the hosts that give rise to carposporophytes and suggests that these adelphoparasites may have originated from perturbations of developmental pathways involved in their host's post-fertilization development.     

AN ELECTRON MICROSCOPE STUDY OF THE EARLY ASSOCIATION BETWEEN TWO MAMMALIAN VIRUSES AND THEIR HOSTS

Early interaction between two animal viruses, vaccinia and adenovirus 7, which multiply readily in L strain and HeLa cells, respectively, was examined in both whole mount preparations and in thin sections. To observe the association at the surface, cells carrying adsorbed virus were swelled under controlled conditions and then "stained" with neutral phosphotungstate. Each particle of both virus types becomes attached to the cell by several capsomeres and is then ingested by phagocytosis. Within the cell, near the surface, single particles or small clumps of adenovirus are lodged within vesicles. Deeper in the cytoplasm this virus is packed in large, numerous inclusions, whereas very close to the nuclear envelope only free particles are found. Vaccinia, on the other hand, either free or in vesicles, is always found in the cytoplasm, at some distance from the nucleus (11). Adsorption and intracellular disposition of these two viruses is discussed in relation to the infectious process.     

黑长臂猿(Hylobates concolor)鸣叫行为研究

本文基于对云南黑长臂猿多年的野外研究,报道其鸣叫行为的一些特性。黑长臂猿通常在上午鸣叫,且大多数发生在930分以前,鸣叫的起始时间具季节性变化,有两个较为集中的时间,一个在730分左右,另一个在830分左右,然而起始时间并不与日出时间一致。黑长臂猿平均每两天鸣叫一次,日鸣叫发生频次在50％左右,鸣叫的发生也随着季节而变化。鸣叫的持续时间无群体的差异,一次鸣叫的平均时间在12分钟左右（除了GG群）,但群体在不同季节鸣叫时间长短不一。本文的研究结果同时还表明一个群体的鸣叫并未引起邻近其它群体的鸣叫。     

THE INCIDENCE AND ORIGIN OF SPOTTED PATTERNS IN THE ESTRILDIDAE

The plumage of the Estrildidae was examined in order to determine the incidence and origin of the spotted patterns.
In the Australian grassfinches a series of feathers showing the derivation of spotted patterns from transverse barring was found in two species. In most species such patterns consisted of single broad spots, but in two species paired spots were present.
The mannikins show three types of spotted pattern. One is derived from transverse barring, another from a rachial streak, and the third from a combination of both bars and streaks. The last one is not a true spotted pattern, the effect being due to overlapping feathers.
The waxbills show spotted patterns derived from transverse barring, the development of which exactly parallels that shown by the grassfinches, but differs in that almost all patterns show paired spots.
The spotted patterns appear to have been derived from a basic barred pattern in most cases, and to represent an increasing complexity of pattern rather than a gradual loss.
It is considered that similar patterns in widely separated species are due to parallel evolution of patterns and not to phylogenetically close relationship.
Where various species show different successive stages in the evolution of a pattern, this does not indicate that one is ancestral to another. Since the species concerned have a common family relationship, the potential for such a pattern may be present throughout the family.
Since the patterns have a function in specific recognition, it is suggested that similar patterns are likely to recur in widely separated localities and that the patterns of sympatric species are likely to differ. If similar patterns are present in one area they will probably indicate close relationship.
The inference of this in relation to plumage pattern problems in some other orders is briefly discussed.     

朱鹮分布与栖息地内农民的关系

1998到 2 0 0 0年间 ,我们在陕西省洋县应用样方法调查了朱 (Nipponianippon)活动区 (面积约10 0 0平方公里 )内所有正在使用的巢和部分往年的旧巢 ,以及主要夜宿地和觅食地 ,并将当地的地形、水系和居民区数字化 ,建立了地理信息系统数据库。通过对其空间位置的统计分析 ,发现朱显著倾向于在村庄附近栖息。朱的活动区与湿地的分布密切相关 ,而村庄都分布在湿地附近。朱与人类保持一定的预警距离 ,同时也对农民的日常活动表现出一定的适应性。我们分析了朱二十年来的繁殖成功率 ,发现它与巢址到农户的距离无关。而且 ,朱营巢的海拔逐年降低 ,其主要活动区正向人口更密的低海拔农村转移。因此 ,我们认为朱对以人类为主导的山村生态系统有良好的适应性。     

褐马鸡血液生理生化指标及雏鸟矿物元素含量测定

采用常规方法对褐马鸡的２２项生理生化指标进行了测定。结果表明：血糖和血清无机磷在性别之间有显著性差异（Ｐ〈０．０５）,所测其它生理生化指标在性别之间无显著差异（Ｐ〉０．０５）。测定分析了幼鸟的６种组织器官内锌、铜、锰、铁及１日龄雏鸟体内１０种矿物元素含量。