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1.
ABSTRACT

Observations of European starlings in France, Germany and Australia reveal surprising high similarities in the individual repertoires of whistled songs. The structure of the whistles enabled us to recognize a number of categories, in which some species-specific themes were found everywhere. They appear with the same general characteristics and variation ranges in all populations.

There seems therefore to be a basic species-specific repertoire common to all males, who have also a number of additional individual themes which characterize each male in its colony. These individual themes show also common characteristics in the different populations. The results suggest that a mechanism has evolved which canalizes the patterns to be learned. The existence of such a universal innate species-specific repertoire has also to be related to functional aspects and to the complicated dialects found in this species.  相似文献   

2.
Human remains of a male individual from Cossack, northwestern Australia are described. Absolute dating is not possible but site geomorphology restricts the upper limit to 6500 B.P. Morphologically and metrically the skull differs from those of recent Western Australian male Aborigines, but it is very similar to that of Kow Swamp I and others included in the “robust” prehistoric Australian Aboriginal group (Thorne, 1977). The specimen is important as indicating the widespread nature and probable recency of a large, robust Australian Aboriginal population demonstrably different to recent populations.  相似文献   

3.
We describe songs of the California Thrasher (Toxostoma redivivum), a territorial, monogamous species whose complex songs are composed of extended sequences of phonetically diverse phrases. We take a network approach, so that network nodes represent specific phrases, and links or transitions between nodes describe a subgroup structure that reveals the syntax of phrases within the songs. We found that individual birds have large and largely distinct repertoires, with limited phrase sharing between neighbours and repertoire similarity decaying between individuals with distance apart, decaying also over time within individuals. During song sequences, only a limited number of phrases (ca. 15–20) were found to be actually “in play” at any given time; these phrases can be grouped into themes within which transitions are much more common than among them, a feature contributing to a small-world structure. It appears that such “small-world themes” arise abruptly, while old themes are abandoned more gradually during extended song sequences; most individual thrashers switch among 3–4 themes over the course of several successive songs, and some small-world themes appear to have specific roles in starting or ending thrasher songs.  相似文献   

4.
The comparison of local song variations between a migratory and a sedentary population of starlings shows the species-specificity of the basic categories and of their variation range. Local variations were studied for different themes in the repertoire, near Kaiserslautern (West Germany) during the reproductive season of 1982. Results were compared with those previously obtained in Brittany (France). In the study area in Germany, 80 % of the individuals migrate in autumn whereas the Breton starlings remain near the colony all year. To compare the whistles of individuals of different regions, by examing the important variations in their frequency modulation, it is necessary to know the general basic features of the whistles. Using sonograms, the whistles of starlings can be divided into 8 general classes according to particular criteria: rhythmicity, modulation etc. Five themes, among these 8 classes, are sung by all or most of the individuals (“specific themes”). The analyses of whistles give us the following results:
  • 1 The songs of the migratory population studied in W. Germany contain basic features corresponding to those known in the sedentary French population.
  • 2 Like the Breton starlings, those in Germany show a “theme-specific” dialect distribution: the rhythmic theme shows several variants in an area of a few km2, whereas the uniform simple theme presents only one variant over several 100 km2. For the five themes, the dialectal mosaic is totally different: two birds can have the same variant of one given theme and sing different dialects of another.
  • 3 The themes which, in France, show a great number of variants over a small area present the same tendency towards strong subdivision in dialects in Germany. In the two study areas, no correlation could be found between dialectal boundaries and ecological factors.
  • 4 Considering that two starling populations with very different characteristics show such similarities in their basic song structures and also in their pattern of local variation (in the parameters concerned and in the sizes of the dialect areas) we may suppose that the basic structure of the specific themes could be determined by a genetic program. Some characteristics, like the precise details of the frequency modulation, may be due more to learning and may conform to the local dialect.
  相似文献   

5.
The view according to which damselfly males practice two alternative reproductive tactics of access to females is critically discussed. It is widely accepted that some males (“territorial” ones) have priority as potential female partners, while others (“sneakers” or “wanderers”) are incapable of retaining an individual territory. They have a chance of mating only by intruding briefly into the area defended by a “territorial” male when a female is present there. Thus, the tactics of a “territorial” male consists in waiting for a female in its territory and copulating with it “by agreement,” whereas non-territorial males resort to forced copulations. By observation of individually marked males (48 out of 118) it was shown that every male could be regarded as “territorial” during a certain period and as a “wanderer” before and after it. Thus, no correlation between the modes of space use by a male (residence/mobility) and the characters of its external morphology and/or signal behavior appears to be possible in principle. According to the data obtained, a more plausible explanation is that the female chooses not the male but the best area for oviposition. In addition, it was ascertained that adherence to forced copulations cannot constitute successful “tactics” since they rarely result in insemination, neither by “territorial” nor “non-territorial” males. In other words, we are dealing not with certain alternative tactics (i.e., specialized adaptive mechanisms that have evolved in the species) but simply with the results of different sets of circumstances at a given moment.  相似文献   

6.
“Hardwired” is a term commonly used to describe the properties of certain behaviors or brain regions. As its usage has increased exponentially in the past 50 years, both in popular media and the scholarly literature, the concept appears to have gained a cloak of respectability in scientific discourse. However, its specific meaning is difficult to pinpoint. In this paper, I examine how “hardwired” has been used in the psychological and neuroscientific literature. The analysis reveals two major themes: one centers on certain purported characteristics of behaviors or brain regions, such as fixedness; the other places these and other characteristics within an evolutionary framework. Overall, the analysis reveals a degree of overlap between “hardwiring” and the folk biology concept of innateness. Various complications arise from such overlap, casting doubts on the usefulness and legitimacy of “hardwired” in scientific discourse.  相似文献   

7.
《Comptes Rendus Palevol》2008,7(8):541-556
In the present article, the Middle and Late Miocene carnivoran faunas of Europe and Africa are compared for establishing their relationships. The Middle Miocene carnivoran assemblages from both continents are quite different at the specific and generic levels, less expressed in family composition. The comparison of the Late Miocene carnivoran assemblages indicates the following: the African carnivoran assemblage is different from the European ones both at the generic and specific level; the carnivoran faunas of Europe can be split into two geographic groups, “western” and “eastern”; the Turolian African assemblage is more diversified at the family level; the African carnivoran assemblage differs from the European ones in the presence of herpestids, the higher abundance of mustelids and the fewer hyaenids. It is more similar to the Late Miocene carnivoran assemblages of western and central Europe than eastern Europe.  相似文献   

8.
1. The distribution of Salix species among the continents. There are about 526 species of Salix in the world, most of which are distributed in the Northern Hemisphere with only a few species in the Southern Hemisphere. In Asia, there are about 375 species, making up 71.29 percent of the total in the world, including 328 endemics; in Europe, about 114 species, 21.67 percent with 73 endemics; in North America, about 91 species, 17.3 percent with 71 endemics; in Africa, about 8 species, 1.5 percent, with 6 endemics. Only one species occurs in South America. Asia, Europe and North America have 8 species in common (excluding 4 cultivated species). There are 34 common species between Asia and Europe, 14 both between Europe and North America and between Asia and North America, 2 between Asia and Africa. Acording to the Continental Drift Theory, the natural circumstances which promoted speciation and protected newly originated and old species were created by the orogenic movement of the Himalayas in the middle and late Tertiary. Besides, the air temperature was a little higher in Asia than in Europe and North America (except its west part) and the dominant glaciers were mountainous in Asia during the glacial epoch in the Quaternary Period. Then willows of Europe moved southwards to Asia. During the interglacial period they moved in opposite direction. Such a to-and-fro willow migration between Asia and Europe and between and North America occurred so often that it resulted in the diversity of willow species in Asia. Those species of willows common among the continents belong to the Arctic flora. 2. The multistaminal willows are of the primitive group in Salix. Asia has 28 species of multistaminal willows, but Europe has only one which is also found in Asia. These 28 species are divided into two groups, “northern type” and “southern type”, according to morphology of the ovary. The boundary between the two forms in distribution is at 40°N. The multistaminal willows from south Asia, Africa and South America are very similar to each other and may have mutually communicated between these continents in the Middle or Late Cretaceous Period. The southern type willows in south Asia are similar to the North American multistaminal willows but a few species. The Asian southern type willows spreaded all over the continents of Europe, Asia and North America through the communication between them before the Quaternany Period. Nevertheless, it is possible that the willows growing in North America immigranted through the middle America from South America. The Asian northern type multistaminal willows may have originated during the ice period. The multistaminal willows are more closed to populars in features of sexual organs. They are more primitive than the willows with 1-3 stamens and the most primitive ones in the genus. 3. The center of origin and development of willows Based on the above discussion it is reasonable to say that the region between 20°-40°N in East Asia is the center of the origin and differentiation of multistaminal willows. It covers Southern and Southwestern China and northern Indo-China Pennisula.  相似文献   

9.
The vocal repertoire, structure, and behavioral context of airborne vocalizations produced by Australian fur seals (Arctocephalus pusillus doriferus) are described using recordings made at a breeding colony on Kanowna Island, Bass Strait, Australia. The study identified six different call types: three produced by males (bark, guttural threat, and submissive call); five produced by females (bark, guttural threat, submissive call, growl, and pup attraction call) and the female attraction call produced by pups and yearlings. Vocalizations were compared according to age and sex classes. The overall structure and function of the pup attraction and female attraction call produced by females, yearlings, and pups, was similar. However, while similar in their overall appearance, certain call types have a lower fundamental frequency when compared with other fur seals. In addition, the male bark call alters in rate of production according to the context used, where calls are slower when males are stationary and advertising their territorial status and faster when males are involved in confrontations with other males or actively herding females. Further research is required to investigate changes in environmental conditions and their effects on shaping the call structure and communication in Australian fur seals.  相似文献   

10.
Aim To characterize the Australian desert vine flora and to compare it with that of deserts in other continents. Location The Stony Deserts, the Simpson Desert and the four main deserts of Western Australia. Methods The Western Australian Herbarium data base and published papers were used to develop vine checklists for each Australian desert studied. A literature search was used to classify the families and genera into phytogeographical elements and to provide data for intercontinental comparisons. Results Thirty‐seven vine species are listed for the six Australian deserts studied. They constitute from 0.8 to 2.7% of the vascular flora, which is within the normal range for arid zone floras. Comparing Australian data with those from the Sonoran and Chihuahuan deserts (North America), for non‐vine taxa, very different phylogenetic lines are present. However, for vines, three of the four most important families are the same in each case, viz. Convolvulaceae, Fabaceae and Asclepiadaceae. This reflects large pantropical and cosmopolitan families shared between all three data sets. At the generic level, in Australia pantropical taxa and taxa from the Old World tropics far outnumber endemic ones, as do pantropical and neotropical genera in North America. Herbaceous vines predominate in Australian deserts as they do in North American ones, but nevertheless, the percentage of woody vines is higher in Australia (32%) than in North America (highest value of 24%). Earlier views that Australian deserts are rich in annual vines are not supported. Main conclusions For many life‐forms, the Australian flora is composed of very different phylogenetic lines to the floras of other continents. However, for desert vines, at the level of family and even of genus, there are surprising similarities between Australia and even a continent as distant as North America, because of shared pantropical and cosmopolitan taxa.  相似文献   

11.
Invasive alien species can have serious adverse impacts on both the environment and the economy. Being able to predict the impacts of an alien species could assist in preventing or reducing these impacts. This study aimed to establish whether there are any life history traits consistently correlated with the impacts of alien birds across two continents, Europe and Australia, as a first step toward identifying life history traits that may have the potential to be adopted as predictors of alien bird impacts. A recently established impact scoring system was used in combination with a literature review to allocate impact scores to alien bird species with self‐sustaining populations in Australia. These scores were then tested for correlation with a series of life history traits. The results were compared to data from a previous study in Europe, undertaken using the same methodology, in order to establish whether there are any life history traits consistently correlated with impact across both continents. Habitat generalism was the only life history trait found to be consistently correlated with impact in both Europe and Australia. This trait shows promise as a potential predictor of alien bird impacts. The results support the findings of previous studies in this field, and could be used to inform decisions regarding the prevention and management of future invasions.  相似文献   

12.
Abstract This paper compares the occurrence of plant traits in five edaphically matched sites at the Barrens, southwestern Australia and the Agulhas Plain, southwestern South Africa. The two regions are very closely matched in terms of their Mediterranean-type climates, landforms, soil types and disturbance regimes. On both continents, matched sites on all substrata (siliceous sand, quartzite, laterite, limestone and calcareous sand) support sclerophyllous shrublands with a similar mix of growth forms. Soils from all substrata in both Australia and South Africa are extremely nutrient-poor except for the calcareous sands where high levels of phosphorus were recorded. Contrary to expectations, Australian soils are not generally less fertile than their South African counterparts. The frequency of species in different leaf consistence categories was similar on the two continents, as was the leaf specific mass of overstorey shrubs from all substrata. Woody plants with leaf spines are significantly more frequent on Australian nutrient-poor substrata. Among woody plants, species with canopy-stored seed are significantly more frequent on Australian nutrient-poor sites, whereas species with bird-dispersed fruits and inter-fire germination are significantly more frequent on South African limestone and calcareous sand. There was good evidence for convergence between the two continents in the frequency of other seed biological traits. The study indicates strong convergence between Australian and South African shrublands in the frequency of a wide range of traits relating to plant form and function. Examples of non-convergence are probably due to regional and historical processes rather than differences in the contemporary physical environments of the two study areas.  相似文献   

13.
14.
A fragment of the large-subunit (LSU) ribosomal RNA gene (rDNA) from the marine dinoflagellates Alexandrium tamarense (Lebour) Balech, A. catenella (Whedon et Kofoid) Balech, A. fundyense Balech, A. affine (Fukuyo et Inoue) Balech, A. minutum Halim, A. lusitanicum Balech, and A. andersoni Balech was cloned and sequenced to assess inter- and intraspecific relationships. Cultures examined were from North America, western Europe, Thailand, Japan, Australia, and the ballast water of several cargo vessels and included both toxic and nontoxic isolates. Parsimony analyses revealed eight major classes of sequences, or “ribotypes,” indicative of both species- and strain-specific genetic markers. Five ribotypes subdivided members of the A. tamarense/catenella/ fundyense species cluster (the “tamarensis complex”) but did not correlate with morphospecies designations. The three remaining ribotypes were associated with cultures that clearly differ morphologically from the tamarensis complex. These distinct sequences were typified by 1) A. affine, 2) A. minutum and A. lusitanicum, and 3) A. andersoni. LSU rDNA from A. minutum and A. lusitanicum was indistinguishable. An isolate's ability to produce toxin, or lack thereof, was consistent within phylogenetic terminal taxa. Results of this study are in complete agreement with conclusions from previous work using restriction fragment-length polymorphism analysis of small subunit rRNA genes, but the LSU rDNA sequences provided finer-scale species and population resolution. The five divergent lineages of the tamarensis complex appeared indicative of regional populations; representatives collected from the same geographic region were the most similar, regardless ofmorphotype, whereas those from geographically separated populations were more divergent even when the same morphospecies were compared. Contrary to this general pattern, A. tamarense and A. catenella from Japan were exceptionally heterogeneous, displaying sequences associated with Australian, North American, and western European isolates. This diversity may stem from introductions of A., tamarense to Japan from genetically divergent sources in North America and western Europe. Alexandrium catenella from Japan and Australia appeared identical, suggesting that these two regional populations share a recent, common ancestry. One explanation for this genetic continuity was suggested by A. catenella cysts transported from Japan to Australia via ships' ballast water: the cysts contained LSU rDNA sequences that were indistinguishable from those of known populations of A. catenella in both Japan and Australia. Ships ballasted in South Korea and Japan have also fostered a dispersal of viable A. tamarense cysts to Australia, but their LSU rDNA sequences indicated they are genetically distinct from A. tamarense/catenella previously found in Australia and genetically distinct from each other, as well. Human-assisted dispersal is a plausible mechanism for inoculating a region with diverse representatives of the tamarensis complex from geographically and genetically distinct source populations. The D1-D2 region of Alexandrium LSU rDNA is a valuable taxo-nomic and biogeographic marker and a useful genetic reference for addressing dispersal hypotheses.  相似文献   

15.
Rats of the GC strain bred for predisposition to catalepsy show, apart from cataleptic “freezing, also an increased “nervousness.” An attempt to select from S55 of the GC strain, on the one hand, expression of the “nervousness,” but, on the other hand, the lack of “nervousness” and duration of the cataleptic “freezing” led to differentiation of S1 and S2 off-springs of the bred groups for the “nervousness,” but not for expression of cataleptic reaction. Study of several behavioral and neurochemical characteristics revealed difference of the both bred groups from Wistar rats similar, this difference being of the same direction, but more pronounced in the “nervous” GC rat off-springs. The conclusion is made about the existence of the common mechanism of catalepsy and “nervousness,” while individual differences of these characteristics are accounted for by effects of conditional tropism or external (most likely, of early maternal) environment, with the latter affecting the “freezing” to the greater degree than the “nervousness.”  相似文献   

16.
This essay traces the ongoing discursive processes through which two former Yugoslav states — Croatia and Slovenia — framed their so-called “exit from the Balkans” and “return to Europe” throughout the 1990s. Applying Maria Todorova's framework of “Balkanism” to these two cases, the essay examines how leaders sought recognition as belonging to Europe, or Central Europe, by defining their respective national identities in opposition to Balkan or Yugoslav ones. What distinguishes Balkanism from other critical traditions such as Orientalism is that the Balkans are located in a distinctively liminal position: at the same time part of Europe as well as its antithetical periphery, the “other” within. This in-between position can often lead to contradictory identity constructions, whereby an insistence on concretizing one's Europeanness coincides with a certain awareness that this European status is never ontologically secure. The essay concludes by considering ways in which the Balkans can be re-imagined, reassembling diverse fragments of Balkan identity into a site for positive engagement and critique.  相似文献   

17.
Aedes albopictus, the “Asian tiger mosquito,” is an aggressive biting mosquito native to Asia that has colonized all continents except Antarctica during the last ~30–40 years. The species is of great public health concern as it can transmit at least 26 arboviruses, including dengue, chikungunya, and Zika viruses. In this study, using double‐digest Restriction site‐Associated DNA (ddRAD) sequencing, we developed a panel of ~58,000 single nucleotide polymorphisms (SNPs) based on 20 worldwide Ae. albopictus populations representing both the invasive and the native range. We used this genomic‐based approach to study the genetic structure and the differentiation of Ae. albopictus populations and to understand origin(s) and dynamics of the recent invasions. Our analyses indicated the existence of two major genetically differentiated population clusters, each one including both native and invasive populations. The detection of additional genetic structure within each major cluster supports that these SNPs can detect differentiation at a global and local scale, while the similar levels of genomic diversity between native and invasive range populations support the scenario of multiple invasions or colonization by a large number of propagules. Finally, our results revealed the possible source(s) of the recent invasion in Americas, Europe, and Africa, a finding with important implications for vector‐control strategies.  相似文献   

18.
Our work is the first study on the vocal repertoire of one of the babbler species, Elliot’s laughingthrush. Field studies were carried out in Hupingshan Nature Reserve, Hunan Province, China. There are three types of signals in the repertoire: songs, calls (chattering), and duets. Songs and calls are used by both males and females. The song consists of a quiet introduction (short note) and a louder main part (two or three tonal notes). There are up to four song variants in the repertoire of a given pair. All songs can be classified into three types. Types I and II represent songs with the main part consisting of three notes, while type III consists of two notes. Types I and II differ from each other in certain features of the frequency modulation shape of the first two notes. All song types can be used during the spontaneous vocalization of a single bird. However, their usage in other contexts differs. Songs of types I and II are more often uttered during vocal interactions of neighbor males. Songs of type III appear to be characteristic of male–female duets. Chattering (calls) is a continuous series of broadband notes. There are several (two to five) note variants in each series. Chattering can be used both during a male–female interaction and as an alarm call. We found an inverse correlation between (1) the duration of pauses between notes, and (2) the number of note variants (“repertoire size”) in a series. Both parameters probably reflect the internal state of an individual at a given moment.  相似文献   

19.
West Nile virus (WNV) is the most widely distributed of the encephalitic flaviviruses and is a major cause of encephalitis, with isolates obtained from all continents, apart from Antarctica. Subsequent to its divergence from the other members of the Japanese encephalitis virus complex, presumably in Africa, WNV has diverged into individual lineages that mostly correspond with geographic distribution. Here we elucidate the phylogeography and evolutionary history of isolates from lineage 1 of WNV. Interestingly, there are many examples of the same amino acid having evolved independently on multiple occasions. In Africa, WNV exists in an endemic cycle, whereas it is epidemic in Europe, being reintroduced regularly from Africa either directly (in western Europe) or via the Middle East (in eastern Europe). Significantly, introduction into other geographic areas has occurred on one occasion only in each region, leading to subsequent establishment and expansion of the virus in these areas. Only one endemic genotype each is present in India and Australia, suggesting that WNV was successfully introduced into these locations once only. Each introduction occurred many centuries ago, probably due to trade and exploration during the 19th century. Likewise, in the Americas, WNV was successfully introduced in 1999 and subsequently became endemic across most temperate regions of North America (NA). In contrast to previous suggestions, an isolate from the epidemic in Israel in 1998 was not the direct progenitor of the NA epidemic; rather, both epidemics originated from the same (unknown) location.  相似文献   

20.
In depth genetic comparisons of populations of Cutleria multifida (Tilopteridales, Phaeophyceae) collected from Europe, the northwestern Pacific Ocean, Australia and New Zealand using the DNA sequences of four gene regions (the mitochondrial cox2 and cox3 genes, the intergeneric spacer region adjacent to cox3, and the open reading frame) suggested that the northwestern European and Japanese populations were considerably greater in terms of their genetic divergence than Mediterranean, Australian or New Zealand populations. The haplotypes of the populations in northwestern European (distribution range including the type locality, seven haplotypes) and Japanese populations (seven haplotypes) were unique except for one shared haplotype. There were weak but positive correlations between the geographical distance and the genetic divergence among northwestern European and Japanese populations. Moreover, both female and male gametophytes occurred in eight of the nine Japanese localities, suggesting Japanese populations showed normal sexual heteromorphic life history of the species. In light of these results, it appears that Japanese populations were native to the area despite earlier hypothesis. In contrast, Australian and New Zealand populations were composed of only one haplotype that is very close to those found in northwestern Europe and Japan, suggesting a recent introduction history from Europe (or from northeastern Asia via Europe) by ship transport to Australia and New Zealand. The Mediterranean populations included two haplotypes identical to those found in northwestern Europe and Japan, and it is suggestive of transoceanic introductions of some populations between Mediterranean and Japanese coasts.  相似文献   

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