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Leslie Brown

Bio: Leslie Brown is an academic researcher. The author has contributed to research in topics: Seasonal breeder & Predation. The author has an hindex of 10, co-authored 13 publications receiving 2215 citations.

Papers
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Book
01 Jan 1982
TL;DR: This is the eighth and final volume in the authoritative Birds of Africa series as discussed by the authors, which covers the Malagasy region which comprises Madagascar and the various islands and archipelagos of the Indian Ocean including the Seychelles, the Comoros, Mauritius and Reunion.
Abstract: This is the eighth and final volume in the authoritative Birds of Africa series. It covers the Malagasy region which comprises Madagascar and the various islands and archipelagos of the Indian Ocean including the Seychelles, the Comoros, Mauritius and Reunion. Every resident and migrant species is covered in full detail, comparable to other volumes in the series, and with a colour map for each species. Vagrants are treated in less detail. All species are illustrated on a beautiful series of 64 colour plates, with original artwork from John Gale and Brian Small.This is a major work of reference on the birds of the region and will remain the standard text for many years to come."

1,035 citations

Book
01 Jan 1968

686 citations

MonographDOI
01 Jan 1980
TL;DR: This is a very reasonable book that should be read and it is actually ease to get this book when the other people must walk around and go outside to get the book in the book store.
Abstract: This is a very reasonable book that should be read. The following may offer you the way to get this book. It is actually ease. When the other people must walk around and go outside to get the book in the book store, you can just be by visiting this site. There is provided link that you can find. It will guide you to visit the book page and get the breeding seasons of east african birds. Done with the download and get this book, start to read.

96 citations

Journal ArticleDOI
03 Apr 2008-Ibis
TL;DR: The Great White Pelican is known to breed more or less regularly in Africa at Lake Shala, Ethiopia; Lake Rukwa, Tanzania; St. Lucia Bay, Natal; Abou Tougour, Chad; Kapsikis, Northern Cameroons; and Wase Rock, Nigeria; and has been observed or reported breeding at Mweru Marsh, Zambia.
Abstract: Summary. Pelecanus onocrotalus roseus is known to breed more or less regularly in Africa at Lake Shala, Ethiopia; Lake Rukwa, Tanzania; St. Lucia Bay, Natal; Abou Tougour, Chad; Kapsikis, Northern Cameroons; and Wase Rock, Nigeria; and has been observed or reported breeding at Mweru Marsh, Zambia; Lake Ngami, Botswana; Seal and Dyers Islands, South Africa; and Lake Natron, Tanzania. The Shala colony, after Lake Rukwa's, is the largest known breeding colony in Africa and is probably of crucial importance to the species in Africa. For successful breeding regular colonies of P. onocrotalus must have an assured supply offish and an inaccessible breeding site. These conditions are met at the Lake Shala colony. Assuming that a Great White Pelican consumes about 10% of body weight or about 900-1,200 g per day, the Lake Shala breeding colony with 7,500-12,000 pairs would consume about 3,140-5,040 tonnes in the breeding seasons. The partially unsuccessful breeding of perhaps 10,000 pairs at Lake Natron in 1962 is described. Failure was attributed to sudden failure of the food supply. Breeding of the Great White Pelican on Lake Shala takes place throughout the year although there is a peak of numbers breeding from December to the end of March, which is in the dry season. Observations recorded in this paper cover two full breeding seasons, 1965-6 and 1966-7. Although during the peak period of breeding the flock at Shala is made up of 2,500-5,000 pairs, this mass is composed of smaller units, each made up of 300-1,200 pairs, laying more or less together with little overlap from one group to the next. Three changes occur in the plumage of the Great White Pelican towards the onset of the breeding season: (a) the development of a knob or swelling on the forehead at the base of the beak with associated expanses of brightly-coloured bare skin, pinkish yellow in males and bright orange in females; (b) the development of a crest; and (c) the development of a yellowish band across the chest or larger areas of darker brown in the plumage. Four distinct colour-types of breeding plumage were observed: the dark-brown type, the brown-breasted type, the yellow-banded type, and the type with scarcely any suggestion of a breast patch. No correlation was found between plumage type and sex, size, length of bill or any other obvious physical feature. Group display and individual displays of the adults are described. There appears to be no special pre-copulation display. Elaborate nests are not prepared; the male collects the nesting material, and both sexes build the nest. Nests are small, 35–60 cm in diameter (averaging 46-4 cm), and close together (364 nests averaged 1–55/m2). Average clutch-size is 1–88. Incubation begins with the first egg; both sexes incubate; the incubation period is probably about 38 days. The fledging period is 65–70 days, of which about the first 28–30 days are spent in the nesting area. After that the young form into groups or “pods”. The development of the young is described. When it is very small it is fed by either parent several times each day. When the young is 30–35 days or older, it is probably fed less than once per day. The bright red nail-like tip of the adult's upper mandible serves to direct the begging movements of the young chick, and it probably holds the liquid food on which the chick feeds. It is suggested that pod formation of young both in the middle of the day and at night possibly helps to avoid extremes of temperature, either of heat or cold. Parents recognise their own chicks; and young pelicans, at a later stage, recognise their parents. Indiscriminate feeding of young does not occur in P. o. roseus. Adults often are quiescent but not asleep at night. Activity is stimulated by the earliest light, and most pelicans begin leaving the island by 09.30-10.00 hrs. Most departures and arrivals take place from about 10.00 to 16.00 hrs. The distance from which food is brought to the colony is not known for certain, but most birds probably fly to and from Lake Abiata. It is not known where the young go once they leave the colony; most do not fly to the obvious place, Lake Abiata. Although difficult to determine, we suggest that the breeding success of the pelicans is on the average less than one young per nest. Egyptian Vultures were the most important predators at the colony, but all forms of predation together accounted for less than 10% of the nesting losses. The timing of breeding in relation to food supply, climatic factors and inaccessibility of the breeding site is discussed. Inaccessibility appears to override seasonal factors, but in permanently inaccessible sites the peak of breeding is in the dry season. It is suggested that the Great White Pelican nests in discrete breeding units within the main colony to minimise the effect of predation.

82 citations


Cited by
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Journal ArticleDOI
TL;DR: Throughout, emphasis will be placed on strategic aspects of feeding rather than on what Holling (75) has called "tactics," and possible answers to the first problem may be given to the second problem.
Abstract: Natural history is replete with observations on feeding, yet only recently have investigators begun to treat feeding as a device whose performance­ as measured in net energy yield/feeding time or some other units assumed commensurate with fitness-may be maximized by natural selection (44, 1 13, 135, 156, 181) . The primary task of a theory of feeding strategies is to specify for a given animal that complex of behavior and morphology best suited to gather food energy in a particular environment. The task is one, therefore, of optimization, and like all optimization problems, it may be tri­ sected: 1. Choosing a currency: What is to be maximized or minimized? 2. Choosing the appropriate cost-benefit functions: What is the mathematical form of the set of expressions with the currency as the dependent variable? 3. Solving for the optimum: What computational technique best finds ex­ trema of the cost-benefit function? In this review, most of the following section is devoted to possible answers to the first problem. Then four key aspects of feeding strategies will be considered: (a) the optimal diet, (b) the optimal foraging space, (c) the optimal foraging period, and (d) the optimal foraging-group size. For each, possible cost-benefit formulations will be discussed and compared, and predictions derived from these will be matched with data from the literature on feeding. Because the third problem is an aspect of applied mathematics, it will be mostly ignored. Throughout, emphasis will be placed on strategic aspects of feeding rather than on what Holling (75) has called "tactics."

3,356 citations

Journal ArticleDOI
21 Apr 2006-Science
TL;DR: Current knowledge on global patterns of influenza virus infections in wild birds is reviewed, these patterns are discussed in the context of host ecology and in particular birds' behavior, and some important gaps in current knowledge are identified.
Abstract: The outbreak of highly pathogenic avian influenza of the H5N1 subtype in Asia, which has subsequently spread to Russia, the Middle East, Europe, and Africa, has put increased focus on the role of wild birds in the persistence of influenza viruses. The ecology, epidemiology, genetics, and evolution of pathogens cannot be fully understood without taking into account the ecology of their hosts. Here, we review our current knowledge on global patterns of influenza virus infections in wild birds, discuss these patterns in the context of host ecology and in particular birds' behavior, and identify some important gaps in our current knowledge.

1,726 citations

Book
17 Mar 1996

1,701 citations

Journal ArticleDOI
04 Jan 2013-Science
TL;DR: A global map of zoogeographic regions is generated by combining data on the distributions and phylogenetic relationships of 21,037 species of amphibians, birds, and mammals, and it is shown that spatial turnover in the phylogenetic composition of vertebrate assemblages is higher in the Southern than in the Northern Hemisphere.
Abstract: Modern attempts to produce biogeographic maps focus on the distribution of species, and the maps are typically drawn without phylogenetic considerations. Here, we generate a global map of zoogeographic regions by combining data on the distributions and phylogenetic relationships of 21,037 species of amphibians, birds, and mammals. We identify 20 distinct zoogeographic regions, which are grouped into 11 larger realms. We document the lack of support for several regions previously defined based on distributional data and show that spatial turnover in the phylogenetic composition of vertebrate assemblages is higher in the Southern than in the Northern Hemisphere. We further show that the integration of phylogenetic information provides valuable insight on historical relationships among regions, permitting the identification of evolutionarily unique regions of the world.

1,014 citations

Journal ArticleDOI
TL;DR: It is concluded that vervet alarm calls function to designate different classes of external danger, and context was not a systematic determinant of response.

876 citations