نتایج جستجو برای: small birds

تعداد نتایج: 826161  

2015
Guillermo Navalón Jesús Marugán-Lobón Luis M. Chiappe José Luis Sanz Ángela D. Buscalioni

Despite a wealth of fossils of Mesozoic birds revealing evidence of plumage and other soft-tissue structures, the epidermal and dermal anatomy of their wing's patagia remain largely unknown. We describe a distal forelimb of an enantiornithine bird from the Lower Cretaceous limestones of Las Hoyas, Spain, which reveals the overall morphology of the integument of the wing and other connective str...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1990
D W Steadman P V Kirch

Mangaia (Cook Islands) consists of a weathered volcanic interior encircled by limestones known as the makatea. Excavations at Tangatatau Rockshelter (site MAN-44), located on the inner cliff of the makatea, produced a stratified sequence of Polynesian artifacts and faunal remains ranging from A.D. 1000-1100 to A.D. 1500-1600. Resident species of birds represented at MAN-44 include nine seabirds...

Journal: :Journal of neurophysiology 2010
Jorge M Méndez Analía G Dall'Asén Brenton G Cooper Franz Goller

Vocal learning, a key behavior in human speech development, occurs only in a small number of animal taxa. Ontogeny of vocal behavior in humans and songbirds involves acquisition of an acoustic model, which guides the development of self-generated vocalizations (sensorimotor period). How vocal development proceeds in the absence of an acoustic model is largely unknown and cannot be studied direc...

2006
GEORGE L. HUNT FRIDTJOF MEHLUM

We recorded the distribution and abundance of marine birds in the northern Barents Sea from 27 February to 8 March 1987 and from 20 to 31 May 1988. Birds were more abundant in waters associated with pack ice than in open water away from pack ice. Within the pack ice, thick-billed murres (Uria lomvia) were the most commonly encountered birds in both periods. Murre densities in the pack ice north...

Journal: :Proceedings. Biological sciences 2016
Duarte S Viana Laura Gangoso Willem Bouten Jordi Figuerola

Long-distance dispersal (LDD) promotes the colonization of isolated and remote habitats, and thus it has been proposed as a mechanism for explaining the distributions of many species. Birds are key LDD vectors for many sessile organisms such as plants, yet LDD beyond local and regional scales has never been directly observed nor quantified. By sampling birds caught while in migratory flight by ...

2011
Esteban Fernández-Juricic Victor Kowalski

Predator detection is improved when individuals join groups. Theory assumes that the transfer of social information about predators among individuals is immediate and accurate. However, animals in groups space themselves at different distances. Little is known about the shape of the social information transfer function over distance, which can affect group cohesion and ultimately the costs and ...

Journal: :The Veterinary record 1973
J E Cooper L Frank

Despite extensive work-on mammals there is a shortage of accurate data on the anaesthesia of birds. Those publications which exist frequently fail to supply information on the methods used to assess the depth of anaesthesia, as was emphasized by Jordan, Sanford and Wright (1960). Birds have a high metabolic rate and a specialized respiratory system and hence frequently react poorly or adversely...

2017
Irene Campderrich Guiomar Liste Inma Estevez

Domestic fowl in small groups are assumed to establish hierarchical systems based on individual recognition. Conversely, interactions in large groups are modulated by badges of status. Previous studies suggested that birds differing in phenotypic appearance (PA) became targets for aggression, possibly mistaking altered PA for badges of status. We evaluated the impact of altering PA on 0, 30, 50...

2015
Crisley de Camargo H. Lisle Gibbs Mariellen C. Costa Glaucia Del-Rio Luís F. Silveira Adriane P. Wasko Mercival R. Francisco Sam C Banks

Small populations of endangered species can be impacted by genetic processes such as drift and inbreeding that reduce population viability. As such, conservation genetic analyses that assess population levels of genetic variation and levels of gene flow can provide important information for managing threatened species. The São Paulo Marsh Antwren (Formicivora paludicola) is a recently-described...

Journal: :Biological reviews of the Cambridge Philosophical Society 2009
Clare McW H Benskin Kenneth Wilson Keith Jones Ian R Hartley

The importance of wild birds as potential vectors of disease has received recent renewed empirical interest, especially regarding human health. Understanding the spread of bacterial pathogens in wild birds may serve as a useful model for examining the spread of other disease organisms, both amongst birds, and from birds to other taxa. Information regarding the normal gastrointestinal bacterial ...

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