Search results for "bird"
showing 10 items of 420 documents
Effetti della cattività su alcuni parametri ematologici del grifone (Gyps fulvus)
2017
Haematological analysis is an essential field of veterinary medicine that provides inexpensive and reliable support to determinate animal health. The knowledge of how different factors affect the normal mean values of blood parameters is key to understand and improve animal health. In order to investigate how captivity can affect the haematological profile of birds of prey, the erythrocyte count, haemoglobin concentration, haematocrit, mean corpuscular volume, total leukocytes count of 123 griffon vultures (Gyps fulvus) were analysed. The birds were divided into 4 groups according to their life conditions: a control group of free-living griffons, 2 semi-captive groups held in an aviary for …
Correction: Phylogeny of the Eurasian Wren Nannus troglodytes (Aves: Passeriformes: Troglodytidae) reveals deep and complex diversification patterns …
2020
The Mediterranean Basin represents a Global Biodiversity Hotspot where many organisms show high inter- and intraspecific differentiation. Extant phylogeographic patterns of terrestrial circum-Mediterranean faunas were mainly shaped through Pleistocene range shifts and range fragmentations due to retreat into different glacial refugia. Thus, several extant Mediterranean bird species have diversified by surviving glaciations in different hospitable refugia and subsequently expanded their distribution ranges during the Holocene. Such a scenario was also suggested for the Eurasian Wren (Nannus troglodytes) despite the lack of genetic data for most Mediterranean subspecies. Our phylogenetic mult…
One hundred and fifty years of ornithology in Sicily, with an unknown manuscript by Joseph Whitaker
2021
A new complete check-list of Birds of Sicily is presented in this paper, with a comparison with previous lists for a period of one hundred and fifty years. Further, an unknown manuscript by Joseph Whitaker “Birds of Sicily”, dated back to ca. 1920, has been transcribed and is here presented integrally. Thus, lists of birds here presented have been separated as follows: i) Doderlein (1869–1874); ii) Whitaker (1920); iii) Iapichino & Massa (1989), Lo Valvo et al. (1993) iv) Corso (2005), Ientile & Massa (2008); v) 2010–2020: Massa et al. (2015) and personal observations; vi) long-term trend: personal observations. Overall, 437 species are listed. Out of 283 species regularly present i…
Effects of the features of contemporary occidental cities on urban avifauna
2022
Desde los primeros asentamientos humanos permanentes del Holoceno, hace 10 000 años, hasta las ciudades contemporáneas, las aves han cohabitado con los seres humanos. En las últimas décadas la urbanización ha crecido exponencialmente en el planeta y, en 2030, más del 60% de la población mundial vivirá en zonas urbanas. En función de su tolerancia a la urbanización las aves se clasifican en tres categorías: evitadoras, adaptadoras o explotadoras urbanas. Las ciudades occidentales contemporáneas atraen a las aves por la presencia de recursos tróficos abundantes y predecibles, la reducción en la diversidad de depredadores o la provisión de estructuras donde ubicar los nidos, entre otras. Sin e…
Predator Mixes and the Conspicuousness of Aposematic Signals
2003
Conspicuous warning signals of unprofitable prey are a defense against visually hunting predators. They work because predators learn to associate unprofitability with bright coloration and because strong signals are detectable and memorable. However, many species that can be considered defended are not very conspicuous; they have weak warning signals. This phenomenon has previously been ignored in models and experiments. In addition, there is significant within- and among-species variation among predators in their search behavior, in their visual, cognitive, and learning abilities, and in their resistance to defenses. In this article we explore the effects of variable predators on models th…
Space matters: meristem expansion triggers corona formation in Passiflora
2015
Background and aims Flower meristems differ from vegetative meristems in various aspects. One characteristic is the capacity for ongoing meristem expansion providing space for new structures. Here, corona formation in four species of Passiflora is investigated to understand the spatio-temporal conditions of its formation and to clarify homology of the corona elements. Methods One bird-pollinated species with a single-rowed tubular corona (Passiflora tulae) and three insect-pollinated species with three (P. standleyi Killip), four (P. foetida L. ‘Sanctae Martae’) and six (P. foetida L. var. hispida) ray-shaped corona rows are chosen as representative examples for the study. Flower developmen…
Heterophyid trematodes (Digenea) from penguins: A new species of Ascocotyle Looss, 1899, first description of metacercaria of Ascocotyle (A.) patagon…
2019
Two species of heterophyid trematodes were found in the Magellanic penguin, Spheniscus magellanicus (Forster), from Patagonia, Argentina. Ascocotyle (Ascocotyle) patagoniensis Hernández-Orts et al. (2012) is re-described based on new, properly fixed specimens (original material from South American sea lion, Otaria flavescens Shaw, was from frozen hosts). Metacercariae of this species are reported and described for the first time from the heart of the silversides, Odontesthes argentinensis (Valenciennes) and O. smitti (Lahille), from Patagonia. Ascocotyle (Phagicola) cameliae n. sp. is described from the intestine of S. magellanicus. The new species is placed into the subgenus Phagicola Faus…
Assessing the Cost of Mounting an Immune Response
2003
International audience; The evolution of parasite resistance has often been assumed to be governed by antagonistic selection pressures. Defense against pathogens, by mounting an immune response, confers evident benefits but may also incur costs, so that the optimal level of defense is expected to depend on the balance between benefits and costs. Although the benefits of immune surveillance are well known, estimates of costs are still equivocal. Here we studied the behavioral and physiological modifications associated with exposure to a onreplicating antigen (lipopolysaccharide [LPS] of Escherichia coli) in a passerine species, the house sparrow (Passer domesticus).We further investigated wh…
Immune-mediated change in the expression of a sexual trait predicts offspring survival in the wild.
2011
9 pages; International audience; BACKGROUND: The "good genes" theory of sexual selection postulates that females choose mates that will improve their offspring's fitness through the inheritance of paternal genes. In spite of the attention that this hypothesis has given rise to, the empirical evidence remains sparse, mostly because of the difficulties of controlling for the many environmental factors that may covary with both the paternal phenotype and offspring fitness. Here, we tested the hypothesis that offspring sired by males of a preferred phenotype should have better survival in an endangered bird, the houbara bustard (Chlamydotis undulata undulata). METHODOLOGY/PRINCIPAL FINDINGS: We…
Reproductive Biology and Its Impact on Body Size: Comparative Analysis of Mammalian, Avian and Dinosaurian Reproduction
2011
Janis and Carrano (1992) suggested that large dinosaurs might have faced a lower risk of extinction under ecological changes than similar-sized mammals because large dinosaurs had a higher potential reproductive output than similar-sized mammals (JC hypothesis). First, we tested the assumption underlying the JC hypothesis. We therefore analysed the potential reproductive output (reflected in clutch/litter size and annual offspring number) of extant terrestrial mammals and birds (as "dinosaur analogs") and of extinct dinosaurs. With the exception of rodents, the differences in the reproductive output of similar-sized birds and mammals proposed by Janis and Carrano (1992) existed even at the …