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1.
Max Maddock  David Geering 《Ostrich》2013,84(2):191-203
Maddock, M. & Geering, D. 1994. Range expansion and migration of the Cattle Egret. Ostrich 65: 191–203.

The expansion of the range of the Cattle Egret Bulbulcus ibis from its origins in tropical Africa and Asia to Europe, the Americas and Australasia are summarised, and implications of research in Australasia based on birds marked with patagial tags on the spread of the species discussed.  相似文献   

2.
《Bird Study》2012,59(3):413-419
ABSTRACT

Capsule: Collective roosting behaviour of the Cattle Egret Bubulcus ibis was influenced by the weather and the season.

Aims: To document the roosting behaviour of the Cattle Egret and assess the relationship between weather conditions and four components of the roosting behaviour including the population size, duration of roost occupancy, the timing of roost gathering and the rate of arrival at roost.

Methods: We recorded the number and arrival times of individuals occupying a communal roost site in northeast Algeria in 2013–2014 between December and April.

Results: There was a seasonal decline of the flock size and rate of arrival and a seasonal increase in the duration of gathering. Weather conditions affected all variables assessed in roosting behaviour such that bad weather lowered the number of individuals in the roost, lengthened the duration and advanced the timing of gathering, and reduced the rate of gathering in the roost.

Conclusion: Our study highlights the importance of weather conditions in shaping the collective roosting behaviour of a gregarious species. Our results suggest that future changes in climatic conditions might influence the collective behaviour of the Cattle Egret in particular and gregarious birds in general.  相似文献   

3.
 The influence of ultraviolet (UV) radiation in simulated natural sunlight on the viability of ascospores of Mycosphaerella fijiensis, the cause of Black Sigatoka disease in banana and plantain, has been investigated as part of a study to assess the windborne spread of this pathogen from mainland Central and South America into the Caribbean. Spores were killed following continuous exposure to UV radiation for periods of 6 h or over. This relatively short exposure time suggests that the distances over which viable spores can be transported will be determined not only by the speed of the wind but also the amount of cloud cover and the time off day that spore release occurs. On this basis, wind dispersal of viable spores over distances greater than a few hundred kilometres is unlikely. These conclusions are reinforced by an examination of historical reports of the arrival of the disease in previously uninfected areas of the Americas and Africa. Received: 10 February 1997 / Accepted: 30 March 1998  相似文献   

4.
Vagrant southern elephant seals (Mirounga leonina) are occasionally sighted along the coast of South Africa and are known to feed primarily on fish and squid. Phocid seals are not known to predate on mammals making the events described here exceptional. This note describes the successful and failed attempts of a vagrant male southern elephant seal (M. leonina) to consume Cape fur seal (Arctocephalus pusillus pusillus) pups in Plettenberg Bay, South Africa. Observations were made by crew and passengers aboard a commercial whale-watching vessel during November 2012. This is the first account of elephant seals eating anything other than fish, squid and penguins and suggests considerable plasticity in prey choice dictated by environmental conditions.  相似文献   

5.
The invasion of tilapia can result in substantial impacts on native communities. Thus, understanding the spatial dynamics of invasions may help prevent future introductions and mitigate impacts. This study estimated the environmentally suitable areas for occurrence of eight tilapia species (genera Coptodon, Oreochromis, Pelmatolapia, and Sarotherodon) in the Americas and their invasive potential using Ecological Niche Models (ENMs). The United States is the most invaded country, receiving all tilapia species. In South America, the southeast and south regions of Brazil are highlighted as the areas where two species are concentrated. The ENMs predicted that all tilapia species have high invasive potential in the Americas, and despite having more tilapias in North America, South and Central Americas are more susceptible to tilapia invasion. All South American basins were predicted to harbor tilapia species that have not yet arrived on the subcontinent. Our study evidences the need to implement management measures and governmental policies in the Americas to deal with problems caused by tilapia introductions. In North America, the focus is on the control of tilapia populations and in Central and South America priority should be given to contention of introduction processes.  相似文献   

6.
F. J. R. Junor 《Ostrich》2013,84(4):193-205
Tomlinson, D. N. S. 1979. Interspecific relations in a mixed heronry. Ostrich 50:193-198.

Fortnightly censuses were conducted at a heronry in Lake Kyle, Rhodesia, from January toMay1974, and while certain species (Reed Cormorant Phalacrocorax africanus, Grey Heron Ardea cinerea and Black headed Heron Ardea melanocephala) continued to arrive in small parties throughout the breeding season, others (Great White Egret Egretta aha, Cattle Egret Bubulcus ibis and Night Heron Nycticorax nycticorax) exhibited a high degree of breeding synchrony. P. africanus showed a significant nesting association with A. cinerea and A. melanocephala, while N. nycticorax was associated with C. albus. B. ibis did not show any significant nesting association with the other species.  相似文献   

7.
A growing and more affluent human population is expected to increase the demand for resources and to accelerate habitat modification, but by how much and where remains unknown. Here we project and aggregate global spatial patterns of expected urban and agricultural expansion, conventional and unconventional oil and gas, coal, solar, wind, biofuels and mining development. Cumulatively, these threats place at risk 20% of the remaining global natural lands (19.68 million km2) and could result in half of the world’s biomes becoming >50% converted while doubling and tripling the extent of land converted in South America and Africa, respectively. Regionally, substantial shifts in land conversion could occur in Southern and Western South America, Central and Eastern Africa, and the Central Rocky Mountains of North America. With only 5% of the Earth’s at-risk natural lands under strict legal protection, estimating and proactively mitigating multi-sector development risk is critical for curtailing the further substantial loss of nature.  相似文献   

8.
Rosemary H.  Lowe-McConnell 《Ibis》1967,109(2):168-179
The success of the immigrant Cattle Egret Ardeola ibis in Guyana appears to be due mainly to its breeding biology, combined with man's activities in clearing and draining land for stock and by his selective shioting.
Long.-established heronries are beine taken over bv the Cattle Egret. In Aurmst 1959 during the principal nesting season in the main rains 90% of the 1786 heron nests in the Botanic Gardens Georgetown, belonged to Cattle Egrets, the others to Little Blue Herons Hydranassa caerutea , Black-crowned Night Herons Nycticorac nycticorux , Snowy Egrets Egretta thula , Tricolour Herons Hydranassu tricolor , and Streaked Herons Butorides striatus . In the December rains the same year another 1700 Cattle Egret nests were in use here, but no indigenous herons were nesting. These were, however, joined in January by Black-crowned Night Herons, Snowy Egrets, Little Blue and Tricolour Herons.
In addition to having two peak nesting periods a year, instead of one as the indigenous herons generally have, the Cattle Egrets react faster to the onset of the rains and obtain the best nest-sites, and they are helped by the tendency of the indigenous herons to display more aggressively against their own species than against the intruder; also now that Cattle Egret numbers are high they can find mates very rapidly. Both indigenous herons and Cattle Egrets have one to three young per brood in Guyana, and the nesting period lasts about two months.
The peak nesting time varies from year to year with the advent of the rains. Nesting appears to be stimulated by, and its success related to, rainfall. A cycle of wet years in Guyana preceded the arrival of the Cattle Egrets in North America in 1952. In Guyana their dispersal inland was restricted, probably by the forest, until 1961.  相似文献   

9.
We examined the phylogenetic relationships of 16 northern species of the aplocheiloid genus Rivulus inhabiting the Caribbean, Central America, and South America. A total of 714 base pairs per taxon were sequenced from two segments of the mitochondrial genome, 12S rRNA and cytochrome b. Both parsimony and neighbor-joining analyses suggest an ancient vicariant origin of the Greater Antillean taxa, in addition to a quite recent dispersal of species into the Lesser Antilles from the South American mainland. Combined analyses support the monophyly of the northern South American assemblage as the sister group of a Central American/Columbian biota. However, the monophyly of the Central American biota remains uncertain. Divergence estimates for the Central American taxa are calibrated from the Last Cretaceous separation of the proto-Antilles from the Americas. These data suggest that the extant Central American taxa represent the descendants of at least two separate invasions during the Cenozoic, prior to the closing of the Panamanian isthmus. Times are consistent with the extensive evidence for reptilian and mammalian exchange throughout the Cenozoic.   相似文献   

10.
How did Asteraceae (the daisy family) expand from its area of origin and become so widespread? This question has challenged generations of evolutionary botanists. Molecular phylogenetic and biogeographic analyses indicate a South American origin of Asteraceae, a view supported by the recent discovery of the earliest fossils of the family in Middle Eocene (ca. 50 Ma) deposits in southern South America. The early-branching lineages in the phylogenetic tree of Asteraceae are South American and African, suggesting that the earliest successful colonization of areas outside South America may have involved long-distance dispersal to Africa. However, one particularly challenging unanswered question is how early members of Asteraceae reached Africa at a time when the Atlantic Ocean constituted a barrier between the two continents. Morphological, phylogenetic, geographic, paleogeographic, and paleontologic data have been combined to propose scenarios on possible geographical and dispersal routes and vectors of dispersion of early-branching lineages of Asteraceae from South America to Africa. Of the different scenarios proposed here, two concern alternative geographical routes: (1) via the Rio Grande Rise-Walvis Ridge axis in the South Atlantic; or (2) via Antarctica, possibly including the Subantarctic islands. Three scenarios consider different dispersal routes: (1) stepping-stones; (2) single-step; and (3) sweepstakes. Finally, three vectors of dispersion are considered: (1) birds; (2) wind; and (3) floating islands. Evaluation of these scenarios suggests that early-branching lineages of Asteraceae probably dispersed from South America to Africa along an island chain formed by the Rio Grande Rise and the Walvis Ridge, transported by birds, possibly combined with rafting and/or sweepstakes. Morphological changes typically associated with evolution on islands characterize many African carduoid descendants, providing indirect evidence for step-wise dispersal along the island chain.  相似文献   

11.
Samples of 31 populations of Parthenium hyserophorus from varius areas of its world distribution were examined for their sesquiterpene lactone composition. On the basis of the occurrence of sesquiterpene lactones the samples were divided into seven chemical types. The most common is a type represented by plants containing parthenin as a major sesquiterpene lactone, and coronopilin and tetraneurin-A. All samples from North and Central America, Venezuela, South Africa, India, Australia, and one sample from Jamaica belong to this type. This suggests that P. hysterophorus recently introduced to South Africa, India and Australia originates in North and (or) Central America. On the other hand, there is a great diversity among examined South American populations. Plants from these populations usually contain hymenin which is their major sesquiterpene lactone. Some populations may also contain coronopilin, hysterin, and dihydroisoparthenin. A high diversity in the sesquiterpene lactone chemistry and the morphological differences between individual South American populations of this species indicate the possible existence of several taxa.  相似文献   

12.
The evolution of yellow fever virus over 67 years was investigated by comparing the nucleotide sequences of the envelope (E) protein genes of 20 viruses isolated in Africa, the Caribbean, and South America. Uniformly weighted parsimony algorithm analysis defined two major evolutionary yellow fever virus lineages designated E genotypes I and II. E genotype I contained viruses isolated from East and Central Africa. E genotype II viruses were divided into two sublineages: IIA viruses from West Africa and IIB viruses from America, except for a 1979 virus isolated from Trinidad (TRINID79A). Unique signature patterns were identified at 111 nucleotide and 12 amino acid positions within the yellow fever virus E gene by signature pattern analysis. Yellow fever viruses from East and Central Africa contained unique signatures at 60 nucleotide and five amino acid positions, those from West Africa contained unique signatures at 25 nucleotide and two amino acid positions, and viruses from America contained such signatures at 30 nucleotide and five amino acid positions in the E gene. The dissemination of yellow fever viruses from Africa to the Americas is supported by the close genetic relatedness of genotype IIA and IIB viruses and genetic evidence of a possible second introduction of yellow fever virus from West Africa, as illustrated by the TRINID79A virus isolate. The E protein genes of American IIB yellow fever viruses had higher frequencies of amino acid substitutions than did genes of yellow fever viruses of genotypes I and IIA on the basis of comparisons with a consensus amino acid sequence for the yellow fever E gene. The great variation in the E proteins of American yellow fever virus probably results from positive selection imposed by virus interaction with different species of mosquitoes or nonhuman primates in the Americas.  相似文献   

13.
14.
During the first half of the twentieth century, two accidental cases of introduction of Pissodes weevils were recorded from the southern hemisphere. The weevils in South Africa were identified as the deodar weevil (Pissodes nemorensis) and those in South America as the small banded pine weevil (Pissodes castaneus). Wide distribution of the two species in their invasive range, general difficulty in identifying some Pissodes spp., and the varying feeding and breeding behaviours of the species in South Africa has necessitated better evidence of species identity and genetic diversity of both species and population structure of the species in South Africa. Barcoding and the Jerry-to-Pat region of the COI gene were investigated. Morphometric data of the South African species was analysed. Our results confirmed the introduction of only one Pissodes species of North American origin to South Africa. However, this species is not P. nemorensis, but an unrecognized species of the P. strobi complex or a hybrid between P. strobi and P. nemorensis. Only P. castaneus, of European origin, was identified from South America. We identified ten mitochondrial DNA haplotypes from South Africa with evidence of moderate genetic structure among geographic populations. Terminal leader and bole-feeding weevils did not differ at the COI locus. A single haplotype was identified from populations of P. castaneus in South America. Results of the present study will have implications on quarantine, research and management of these insect species.  相似文献   

15.
Six new genera and eight new species are described from South and Central Americas, South Africa, and Southeastern Asia. Illustrations of the male genitalia of the type species of the genera Duiliopsis Bergevin and Perindus Emeljanov are given. The generic name Duiliopsis is synonymized with Duilius Stål. The synonymy of the generic name Hemitropis Fieber with Duilius is supported.  相似文献   

16.
Teak (Tectona grandis Linn. f.) is one of the major plantation timbers of the world. The species is native to India, Myanmar, Thailand and Laos in South East Asia but was translocated to several countries in Africa and Central and South America during the past century. Today, large areas of plantations are grown outside the species native range. It is speculated that genetic bottlenecks and founder effects combined with new selection pressures under new growing conditions have led to the formation of distinct landraces; this hypothesis is supported by results from international provenance tests. In the present study, we apply genetic markers to identify the likely origin of teak grown outside its native range and examine if the landraces show signs of reduced genetic diversity. We find large variation in the level of diversity among landraces, although not larger than that observed among native populations. We conclude that variation in the studied teak landraces probably reflects their areas of genetic origin rather than severe founder effects created during their introduction. The genetic data suggests that the studied landraces originated from either the semi-moist east coast of India, southern Myanmar or western Thailand. These results indicate that translocation of teak has mainly come from a certain part of the native distribution and that this did not include the widespread natural teak areas of southern, dry interior or western India or northern Myanmar.  相似文献   

17.
With increasing availability of plant distribution data, the information about global plant diversity is improving rapidly. Recently, Ulloa Ulloa et al. (2017) presented the first comprehensive overview of the native vascular flora of the Americas, yielding a total count of 124,993 native species. Of these, 51,241 occur in North America and 82,052 in South America. By combining these data with the information in the Global Naturalized Alien Flora (GloNAF) database of naturalized alien floras, we point out that for a complete picture of the regional and continental plant richness, the naturalized alien species need to be considered. Ignoring this novel component of regional floras can lead to an inaccurate picture of overall change in biodiversity in the Anthropocene. We show that North and South America might face contrasting challenges in terms of potential threats to biodiversity posed by alien plant species, because of the different past and present dynamics of invasions and predictions of future development. In total, there are 7,042 naturalized alien plants occurring in the Americas, with 6,122 recorded in North America and 2,677 in South America; if only introductions from other continents are considered additions to the native continental flora make up 6.9 and 1.4 %, respectively. Nevertheless, predictions of naturalized plant trajectories based on global trade dynamics and climate change suggest that considerable increases in naturalized plant numbers are expected in the next 20 years for emerging South American economies, which could reverse the present state.  相似文献   

18.
The palm tribe Chamaedoreeae reaches its higher diversity in Central America, however, its distribution ranges from the north eastern part of Mexico to Bolivia with a disjunction to the Mascarene Islands in the Indian Ocean. The disjunct distribution of Chamaedoreeae is generally considered a result of Gondwana vicariance and extinction from Africa and/or Madagascar. However, latitudinal migrations and their role in shaping the distribution of this tribe in the Americas have been largely overlooked. In this study we used seven plastid and two nuclear DNA regions to investigate the phylogenetic relationships and biogeography of the Chamaedoreeae. The resulting phylogeny fully resolved the generic relationships within the tribe. The exact area of origin of the tribe remains uncertain, but dating analyses indicated an initial diversification of the Chamaedoreeae during the Early Eocene, followed by long distance dispersion to the Mascarene Islands in the late Miocene. The radiation of Hyophorbe could have taking place on islands in the Indian Ocean now submerged, but its former presence in Africa or Madagascar cannot be ruled out. At least two independent migrations between North and South America predating the rise of the Panama isthmus need to be postulated to explain the distribution of Chamaedoreeae, one during the Middle Eocene and a second during the Miocene. Whereas the traditional interpretation of distribution of Chamaedoreeae species assumes a west Gondwana origin of the group, the findings presented in this paper make it equally possible to interpret the group as a primarily boreotropical element.  相似文献   

19.
The family Ciehlidae is a large group of tropical fishes in the order Perciformes, with an estimated number of living species exceeding 1400. The modern distribution of the family Ciehlidae is predominantly in fresh waters of Central and South America, Africa, Madagascar, India and the Middle East, with fossil members known from Africa, Saudi Arabia, the Levant, Europe, South America and Haiti. Many authors have referred to the distribution as being Gondwanan and have postulated that cichlids originated over 130 million years ago, in the Early Cretaceous. However, the suggested evidence for an Early Cretaceous origin of cichlids is equally or more compatible with a much younger age of origin. Based on the biology and distribution of modern and fossil cichlids, it is more probable that they arose less than 65 million years ago, in the Early Tertiary, and crossed marine waters to attain their current distribution.  相似文献   

20.
The Lophopidae are found in South America, Africa, Australia, India and Southeast Asia. This distribution appears to be typically Gondwanan, triggered by tectonic events beginning over 100 Ma. However, within the Fulgoromorpha, the lophopids are considered to be relatively recently. In this study, biological, geological and phylogenetic information is evaluated to provide a parsimonious explanation for the distribution of the group and its geographic region of ancestral origin. The Lophopidae can be divided into four monophyletic groups. The ancestors of two groups appear to have originated somewhere along the western Pacific island arc system. Another group appears to have an origin in Southeast Asia. A reliable explanation for the ancestral origin of the fourth group was not possible because it consists of only one genus present in Central and South America. A biogeographic map of the two groups of lophids of the western Pacific island arc is concordant with their phylogeny based on biological and morphological data. Based on this finding, the best explanation for the origin and evolution of the Lophopidae and their current distribution of these lophopids is through vicariance. Similar types of eco-evolutionary events explain radiation and distribution of the Lophopidae, in general.  相似文献   

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