Molecular phylogenetics and the diversification of hummingbirds.
Current Biology 24 (8): 910–916. doi:10.1016/j.cub.2014.03.016. PMID 24704078.
The tempo of species diversification in large clades can reveal fundamental evolutionary mechanisms that operate on large temporal and spatial scales. Hummingbirds have radiated into a diverse assemblage of specialized nectarivores comprising 338 species, but their evolutionary history has not, until now, been comprehensively explored. We studied hummingbird diversification by estimating a time-calibrated phylogeny for 284 hummingbird species, demonstrating that hummingbirds invaded South America by ∼22 million years ago, and subsequently diversified into nine principal clades. Using ancestral state reconstruction and diversification analyses, we (1) estimate the age of the crown-group hummingbird assemblage, (2) investigate the timing and patterns of lineage accumulation for hummingbirds overall and regionally, and (3) evaluate the role of Andean uplift in hummingbird speciation. Detailed analyses reveal disparate clade-specific processes that allowed for ongoing species diversification. One factor was significant variation among clades in diversification rates. For example, the nine principal clades of hummingbirds exhibit ∼15-fold variation in net diversification rates, with evidence for accelerated speciation of a clade that includes the Bee, Emerald, and Mountain Gem groups of hummingbirds. A second factor was colonization of key geographic regions, which opened up new ecological niches. For example, some clades diversified in the context of the uplift of the Andes Mountains, whereas others were affected by the formation of the Panamanian land bridge. Finally, although species accumulation is slowing in all groups of hummingbirds, several major clades maintain rapid rates of diversification on par with classical examples of rapid adaptive radiation.
Waterfowl - Ducks, Geese & Swans of the World.
399 Seiten, durchgehend mit Farbfotos illustriert. Sea World Press, San Diego
Inhalt (Ausgabe 1996, 490 Seiten, Verlag Hancock House):
This comprehensive volume covers the natural history of each of over 160 members of the ducks, geese, swans and screamers of the world. Beautifully illustrated and authoritative, this remarkable book is destined to become the ultimate reference work on the waterfowl of the world. The eighteen chapters deal with every aspect of waterfowl biology, including habitat, distribution, plumage, migration, feeding, courtship, predators and mortality. A separate appendix includes weights of virtually every species and subspecies of waterfowl. Concise full-colour range maps accompany each species account. More than 750 beautifully reproduced photographs represent a lifetime of intensive research and field study by the author. This definitive volume on the Anseriformes will prove invaluable to anyone interested in the natural history of the waterfowl -- weather teacher, student, naturalist, bird watcher, conservationist, aviculturist or ornithologist.
The Vanishing Act: A History and Natural History of the Javan Pied Starling Gracupica jalla.
Ardea, 109(1):41-54 (2021). https://doi.org/10.5253/arde.v109i1.a1
The Javan Pied Starling Gracupica jalla, a recent taxonomic split from Asian Pied Starling G. contra, has disappeared almost entirely unnoticed from its native range in Java and Bali, Indonesia; in a circumstance unique in bird conservation, the only known populations are held in bird shops. To provide an evidence base for any future endeavour to re-establish a population in the wild, we reviewed all published information on the species relevant to its conservation, supplemented by specimen label data, unpublished field notes, diaries and manuscripts. A population in eastern Sumatra (nine localities reported, including Bangka) had obscure origins. The species was widespread in Java (168 localities) and Bali (13 localities), and was described as one of the commonest birds in open, i.e. non-forest, lowland country (records up to 1600 m), having a high tolerance of disturbed habitats, especially agricultural areas, with often large roosts inside city limits. It fed mainly on terrestrial invertebrates and fruits, often consuming plant pests and frequently probing dung. It bred all year but chiefly in response to rains, with apparent peaks in January and May in West Java and April in East Java, building conspicuous untidy nests high in trees and laying mostly 3 (2–4) eggs. The cagebird trade is blamed for the massive decline that abruptly became apparent in the late 1990s and early 2000s, but the use of pesticides in Java and Bali's agricultural environment seems likely to have played an unseen role. Searches are needed to find any remnant populations, along with the creation of a programme of captive breeding and research to identify potential areas for reintroduction.
Using historical genome‐wide DNA to unravel the confused taxonomy in a songbird lineage that is extinct in the wild.
Evol. Appl. 2021 Mar; 14(3): 698–709.
Published online 2020 Nov 7. doi: 10.1111/eva.13149
Urgent conservation action for terminally endangered species is sometimes hampered by taxonomic uncertainty, especially in illegally traded animals that are often cross‐bred in captivity. To overcome these problems, we used a genomic approach to analyze historical DNA from museum samples across the Asian Pied Starling (Gracupica contra) complex in tropical Asia, a popular victim of the ongoing songbird crisis whose distinct Javan population (“Javan Pied Starling”) is extinct in the wild and subject to admixture in captivity. Comparing genomic profiles across the entire distribution, we detected three deeply diverged lineages at the species level characterized by a lack of genomic intermediacy near areas of contact. Our study demonstrates that the use of historical DNA can be instrumental in delimiting species in situations of taxonomic uncertainty, especially when modern admixture may obfuscate species boundaries. Results of our research will enable conservationists to commence a dedicated ex situ breeding program for the Javan Pied Starling, and serve as a blueprint for similar conservation problems involving terminally endangered species subject to allelic infiltration from close congeners.
Status der Mandarinente Aix galericulata in der Schweiz.
Ornithol. Beob. 94: 53-63.
Der erste Brutnachweis freilebender Manadarinenten in der Schweiz erfolgte 1958 in Basel. Dort entwickelte sich eine kleine stationäre Population, die von entflogenen Vögeln aus dem Tierpark Lange Erlen stammt. Seit 1974 brütet die Mandarinente auch regelmäßig in der Gegend um Solothurn, wo heute der der größte Bestand lebt. Ab 1981 erfolgten vereinzelt auch Bruten anderswo im schweizerischen Mittelland, fast ausschließlich unter 500 m. ü. M. Drei Typen von Bruthabitaten können unterschieden werden: Parkanlagen, Waldweiher und Laubwälder in der Nähe von Flüßen und Seeufern. Die Schweizerische Pupulation wird heute auf etwa 200 Individuen geschätzt, wovon etwa 10-15 Brutpaare. Genauere Angaben fehlen bisland, da die Mandarinente als exotische Art vor 1994 von den Feldornithologen zu wenig beobachtet wurde.
The origin of out-of-range pelicans in Europe: wild bird dispersal or zoo escapes?
Ibis 150(3), Juli 2008:606–618, doi:10.1111/j.1474-919X.2008.00830.x
We tested whether spatial and annual patterns of occurrence of out-of-range Great White Pelecanus onocrotalus, Dalmatian Pelecanus crispus and Pink-backed Pelicans Pelecanus rufescens recorded in Europe between 1980 and 2004 supported a natural vagrancy theory. Candidate variables tested were those likely to influence dispersal and escape probability (distance to the usual breeding/wintering range, national captive stock), and wild breeding population sizes and their movements (size of breeding colonies, climate conditions on wintering grounds or during dispersal). Spatial vagrancy patterns supported the hypothesis of wild birds dispersing from their normal range, with decreasing national totals with increasing distance to the usual range for the three species. Annual out-of-range numbers of Great White Pelican were predicted by breeding colony size and breeding success in Greece, with a further effect of Sahel rainfall during the previous year. Annual numbers of Dalmatian Pelican were related to the North Atlantic Oscillation index and to breeding success in Greece. Finally, annual numbers of Pink-backed Pelican were predicted by summer Sahel rainfall, which is known to drive dispersal of the species northwards into the sub-Sahelian steppes during wet summers there. Hence, annual vagrancy patterns in Europe were well predicted for all three species by population size indices, reproductive success and/or climatic components, which presumably influence survival and/or dispersal. We therefore consider that vagrancy patterns were driven by wild birds, whereas escapes – even if potentially numerous – do not create sufficient ‘noise’ to hide these patterns.
Rails of the World.
A Monograph on the Family Rallidæ.
406 Seiten, 40 Farbtafeln, 17 Verbreitungskarten.
David R. Godine Publisher, Boston.
Among the least known and most elusive of any major bird species, rails manage to colonize remote islands, impenetrable jungles and desolate shorelines in almost all regions of the world. Particularly interesting is their enigmatic evolution; once having arrived at a suitable habitat, they often lose their power of sustained flight and, over the centuries, their instinct for migration. With the rapid disappearance of their habitats and their vulnerability to predation, this book serves the very important function of establishing scholarship on the rail family.
Breeding Biology of Vanellus chilensis (AVES: Charadriidae) in a Peri-urban Area of Southern Brazil.
Revista de Ciéncia Ambientais 13(3): (ISSN 1981-8858). http://dx.doi.org/10.18316/rca.v13i.6070
The neotropical species Vanellus chilensis, known as Southern Lapwing, is found in grassland environments, in rural and urban open areas. e species is considered a social Bird, which aggregates in pairs or small groups during the breeding period, in austral spring and summer. During the reproductive period, the cooperative breeding behavior is common among individuals of the species, when a non-breeding individual, called "helper", assists the breeding pair in parental care activities. We monitored a total of 11 social breeding unities of V. chilensis between august 2014 and january 2015 in the Universidade do Vale do Rio dos Sinos campus, in São Leopoldo, Rio Grande do Sul. We conducted nest observations, by evaluating the breeding success of individuals regarding eggs and chick's loss, with and without helpers' presence, as well as behavioral aspects. We recorded the laying of 65 eggs, of which 10.7% achieved breeding success, regarding the number of viable chicks. In this study, helpers' presence in the nests did not influence the breeding success of individuals, thus, dismissing the hypothesis that helpers' assistance improves breeding success of the species. Our findings contribute to the knowledge on the breeding biology of V. chilensis in peri-urban areas.
Improved systematics of lorikeets reflects their evolutionary history and frames conservation priorities.
Emu - Austral Ornithology 120 (3): 201–215. doi:10.1080/01584197.2020.1779596. S2CID 222094508.
A well-supported genus-level classification of any group of organisms underpins downstream understanding of its evolutionary biology and enhances the role of phylogenetic diversity in guiding its conservation and management. The lorikeets (Psittaciformes: Loriini) are parrots for which genus-level systematics (phylogenetic relationships and classification) has long been unstable and unsatisfactory. Instability has manifested through frequently changing compositions of some genera (e.g. Trichoglossus and Psitteuteles). Other genera (e.g. Charmosyna, Vini) have become so large that their phenotypic heterogeneity alone at least questions whether they are monophyletic assemblages that genera should comprise. Recent molecular phylogenetic and phenotypic studies have improved the framework with which to rationalise genus-level systematics in lorikeets but some trenchant uncertainty has remained. Here we utilise published genomic data and tetrahedral analysis of plumage colour to develop a full review of the genus-level classification of lorikeets. Using existing phylogenetic relationships and a newly estimated time-calibrated tree for lorikeets, we show where paraphyletic assemblages have misled the classification of genera. We assign six species to three new genera and six other species to four previously described generic names that have been in synonymy in recent literature. Our taxonomic revision brings a new perspective informing and guiding the conservation and management of the lorikeets and their evolutionary biology.
Structure of an African Red-Billed Hornbill (Tockus Erythrorhynchus Rufirostris and T. E. Damarensis) Hybrid Zone as Revealed by Morphology, Behavior, and Breeding Biology.
The Auk 121 (2): 565–586. https://doi.org/10.1093/auk/121.2.565
The distributions of southern African (Tockus erythrorhynchus rufirostris) and Damaraland (T. e. damarensis) Red-billed Hornbills overlap in northern Namibia. Allopatric populations of the taxa have diagnosable differences in habitat, morphology, vocalizations, and displays. We investigated the structure of the hybrid zone using data from morphology, behavior, and breeding biology. The morphological characteristics—eye color and facial plumage color—were summarized as hybrid index scores, which showed a significant positive regression against distance from southwest to northeast across the hybrid zone. Vocalizations also showed a positive relationship between the first principal component (extracted from 12 call variables) and distance across the hybrid zone. However, there appears to be introgression of a T. e. damarensis call into T. e. rufirostris, but not vice versa. In addition, female T. e. damarensis-male T. e. rufirostris breeding pairs occur more frequently than male T. e. damarensis-female T. e. rufirostris pairs. The asymmetrical call introgression may result either from asymmetry in mating or from genetic control of call inheritance. Finally, heterospecific pairs show lower fitness, in the form of reduced hatching success, even when female fitness attributes are included as covariates. Although we are uncertain whether the Red-billed Hornbill hybrid zone is stable, the apparent biological processes operating within it conform to predictions of both the “mosaic” and the “tension zone” models, because both habitat characteristics and a balance of dispersal and selection appear to determine its structure