نتایج جستجو برای: threatened birds
تعداد نتایج: 56319 فیلتر نتایج به سال:
Few of the Pelecaniformes are globally threatened, although some island and inland populations of pelecaniform birds have become extinct in the face of habitat loss and contamination. In some species (e.g., double-crested cormorant, white pelican), numbers are increasing with near-exponential growth, while in others (e.g., Dalmatian pelican) population abundance is rapidly decreasing. Island sp...
Kaka (Nestor meridionalis meridionalis) studied in Big Bush State Forest spent 35% of their feeding time digging out Ochrocydus huttoni larvae from live mountain beech trunks (Nothofagus solandri var. cliffortioides). Larvae of O. huttoni had a high energy value compared to that of other insects. The assimilation efficiency for energy of two captive kaka was 91 j: 3% when fed a diet of O. hut/o...
Slowing rates of global biodiversity loss requires preventing species extinctions. Here we pinpoint centers of imminent extinction, where highly threatened species are confined to single sites. Within five globally assessed taxa (i.e., mammals, birds, selected reptiles, amphibians, and conifers), we find 794 such species, three times the number recorded as having gone extinct since 1500. These ...
We compared the avifauna recorded in a recent survey in an urban park (Parque Municipal Henrique Luís Roessler, Parcão) and surroundings, Novo Hamburgo, RS, with past data, to evaluate the possible alterations in species composition over time. Of the 265 species compiled as original elements of that region, 114 were found at Parcão. Among forest species, 37% were considered locally extinct. The...
The Coscoroba Swan (Coscoroba coscoroba) is an unusual member of the Anatidae found in South America, from the Falkland Islands and Tierra del Fuego through Chile and Argentina, Uruguay, and Paraguay as far north as Mato Grosso do Sul in Brazil. The species is not threatened globally, but some local populations have declined and the status of others is unknown. The objective of this study was t...
Many animals react to danger by producing chemical cues that can be smelled by others, which is called the smell of fear. Some bird species produce chemical compounds when threatened, such as nestlings of the Eurasian roller Coracias garrulus that vomit an odorous orange liquid when scared in their nests. Here, we experimentally explore the possibility that parents were informed about recent pr...
DNA extraction methods for genotyping non-invasive samples have led to great advances in molecular research for ecological studies, and have been particularly useful for analyzing threatened species. However, scarce amounts of fragmented DNA and the presence of Taq polymerase inhibitors in non-invasive samples are potential problems for subsequent PCR amplifications. In this study we describe a...
West Nile virus (WNV) is an avian virus that can cause fatal disease in some species of mammals, reptiles and birds. Most clinical cases occur in humans and horses. Approximately 80% of infected humans remain asymptomatic; 20% have flulike symptoms. Less than 1% develop meningitis, encephalitis or acute paralysis, but some of these cases are fatal or result in permanent impairment. Neurological...
Chewing lice (Phthiraptera) that parasitize the globally threatened swan goose Anser cygnoides have been long recognized since the early 19th century, but those records were probably biased towards sampling of captive or domestic geese due to the small population size and limited distribution of its wild hosts. To better understand the lice species parasitizing swan geese that are endemic to Ea...
Using data for 25,780 species categorized on the International Union for Conservation of Nature Red List, we present an assessment of the status of the world's vertebrates. One-fifth of species are classified as Threatened, and we show that this figure is increasing: On average, 52 species of mammals, birds, and amphibians move one category closer to extinction each year. However, this overall ...
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