Jon Fjeldsa
University of Copenhagen
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Featured researches published by Jon Fjeldsa.
Zoologica Scripta | 2006
Knud A. Jønsson; Jon Fjeldsa
Oscine passerine birds make up almost half of all avian diversity. Relationships within the group, and its classification, have long been controversial. Over the last 10 years numerous molecular phylogenies have been published. We compiled source phylogenies from 99 published studies to construct an oscine supertree. We aimed to illustrate weak and strong parts of the phylogeny and set targets for future phylogenetic work and therefore preferred a heuristic approach where we judged the adequacy of taxon sampling and molecular method of each source tree instead of using matrices and automated tree‐building programs. We present an estimate of the phylogenetic relationships of 1723 extant and one extinct species of oscine passerine birds (Aves: Passeri) — more than 37% of the total. We included 34/35 (97%) families, 38/39 (97%) subfamilies and 40/43 (93%) tribes. Overall resolution is 83% of a fully bifurcating tree. The basal lineages are all distributed in the Australo‐Papuan region, but several more distal lineages dispersed out of this region and radiated in other parts of the world. However, taxa of the Australian region suffer from larger evolutionary gaps and the deep branches of the Sylvioidea and nine South American primaried oscines are still poorly resolved.
The Auk | 2004
Rauri C. K. Bowie; Jon Fjeldsa; Shannon J. Hackett; Timothy M. Crowe
Abstract The double-collared sunbirds of the Eastern Arc Mountains of Tanzania and southeastern Kenya are characterized by regional variation in morphology and plumage. That variation has resulted in considerable dispute over their taxonomic status and delineation of range boundaries. It has been suggested that Moreaus Sunbird (Nectarinia Moreaui) is an atypical phenotype that has arisen from a hybridization event between the more widely distributed Eastern Double-collared Sunbird (N. mediocris) and the narrowly distributed Loveridges Sunbird (N. loveridgei). A discriminant analysis of six standard morphological characters indicates that Moreaus Sunbird is intermediate in shape and size between the Eastern Double-collared and Loveridges sunbirds. There is greater overlap between female Moreaus and Eastern Double-collared sunbirds than between males; Loveridges Sunbird shows little overlap with the other taxa. Discrete plumage characters separate all three taxa. Molecular analyses of 728 base pairs of mitochondrial DNA (NADH3 and control region) suggest that Moreaus Sunbird is a valid taxon and the sister species to Loveridges Sunbird. Eastern Double-collared Sunbird haplotypes can be divided into three distinct clades, separated from each other by substantial genetic divergence (approximately 8–10% sequence divergence). We propose species status for each of those clades and suggest the following three taxa: N. mediocris Shelley 1855, N. usambarica Gröte 1922, and N. fuelleborni Reichenow 1899. Finally, we propose a biogeographical hypothesis of speciation events within the N. mediocris species complex.
Oryx | 2004
Jon Fjeldsa; Neil D. Burgess; Simon Blyth; Helen Margaret De Klerk
The establishment of protected areas for wildlife conservation in Africa was motivated by a number of different reasons (including hunting, recreation and wildlife conservation). The current reserve network provides good coverage of the distributions of the 194 species of larger mammals (> 3 kg) and 51 species of threatened larger mammals. However, it is less effective in covering the distribution of all 197 of Africas threatened mammal species, which includes >140 smaller bodied species ( <3 kg) often restricted to habitat patches. A fully comprehensive network of areas for the conservation of African mammals, especially those facing extinction, is not yet in place, and further reserves may be needed in the Horn of Africa (Somalia in particular), the Cameroon Highlands, parts of the eastern African coastal forests and Eastern Arc Mountains, and parts of the Albertine Rift Mountains. More and larger reserve areas are also required to adequately cover all the species of South Africa. Parts of these gaps are already covered by government forest reserves, and the importance of this reserve category for the conservation of African mammals, especially threatened species, needs to be better recognized. As many of the gaps in reserve coverage are in areas of high human population and good agricultural potential, conservation goals may be difficult to achieve unless we supplement traditional reserves with novel approaches to maintain natural habitats and wildlife outside reserves.
Journal of Zoology | 2002
Helen Margaret De Klerk; Timothy M. Crowe; Jon Fjeldsa; Neil Burgess
Geographical patterns and peaks of species richness and narrow endemism (defined by range-restrictedness and range-size rarity) are described for terrestrial Afrotropical birds and subsets thereof based on residency, endemism, and taxonomy. Species richness for residents and Afrotropical endemics (species globally restricted to sub-Saharan Africa) peaks along the mountains and adjacent lowlands of eastern and southern Africa. Isolated mountains in central and western Africa and the lowlands of the north-eastern Congo Basin (Ituri) are highlighted to a lesser degree. Peaks of narrow endemism occur in these areas as well as in the Ethiopian Highlands (particularly for non-passerines), Somalia (particularly for passerines), and the Angolan Escarpment. Within residents, patterns of species richness vary greatly between Afrotropical endemics (which concentrate in forests on mountains and adjacent lowlands, and the southern Brachystegia woodlands) and non-endemic residents (which concentrate in Sudanian woodlands and the Ethiopian Highlands). Patterns of species richness of residents (species that breed in the Afrotropics) and non-breeding migrants (non-breeding visitors to the Afrotropics) also show notable differences. The latter concentrate in areas close to the Palaearctic, which forms their distributional range centres. Patterns of species richness and narrow endemism for Afrotropical endemics show broad-scale coincidence within mountains or mountain–lowland complexes, particularly the Cameroon–Bamenda Highland system, East African rift system and Eastern Arc mountains. However, fine-scale coincidence of peaks of species richness and narrow endemism within these complexes is low. Narrow endemism peaks occur in areas of topographical complexity, which may have conferred localized climatic stability over short-, medium-, and long-term climatic cycles (sensu Fjeldsa, 1994; Fjeldsaet al., 1997), allowing these areas to act as ‘species pumps’. Species accumulate in areas of high productivity. Lack of fine-scale coincidence of narrow endemism and species richness peaks have implications for conservation prioritization exercises.
Archive | 2005
Jon Fjeldsa; Herbert Tushabe
Because of limited resources for conservation, and conflicts with other interests, systematic priority analysis is now a central task in conservation biology. Because of doubts about how efficient conservation schemes based on samples of biomes are for maintaining biodiversity, a major shift has taken place to use species distribution data compiled for large numbers of species. The spatial resolution of distribution data for regional or global analysis must necessarily be rather coarse, and it is therefore unclear whether identified priority areas will hold viable populations of all the species they are assumed to cover. We tested this using more finely resolved distribution data for forest birds of eastern Africa. The broad priority areas identified using coarse-scale data were corroborated using fine-scale data, and they appear to include suitable conservation sites for the majority of species. Exceptions to this were mainly in zones with few strictly forest-dependent species. Procedures for corrections and for moving on to identifying action sites within broader priority areas are discussed.
Biological Conservation | 2007
Neil Burgess; T.M. Butynski; Norbert J. Cordeiro; Nike Doggart; Jon Fjeldsa; Kim M. Howell; F.B. Kilahama; Simon P. Loader; Jonathan Cranidge Lovett; B. Mbilinyi; Michele Menegon; David Moyer; Evarist Nashanda; A. Perkin; Francesco Rovero; W.T. Stanley; Simon N. Stuart
Molecular Phylogenetics and Evolution | 2006
Rauri C. K. Bowie; Jon Fjeldsa; Shannon J. Hackett; John M. Bates; Timothy M. Crowe
Biological Conservation | 2004
H.M. de Klerk; Jon Fjeldsa; Simon Blyth; Neil D. Burgess
Diversity and Distributions | 2002
H.M. de Klerk; Timothy M. Crowe; Jon Fjeldsa; Neil Burgess
Journal of Avian Biology | 2006
Martin Irestedt; Jon Fjeldsa; Per G. P. Ericson