7 resultados para birds

em DigitalCommons@University of Nebraska - Lincoln


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Though intended as a field guide to the birds of the Great Plains, this book seems to serve best as a general introduction to Great Plains birds and will mostly benefit those casually interested in birds. The definition of Great Plains the book uses is rather broad, and some species are included that, in my opinion, aren't really birds of the Great Plains. For example, several warblers are included as breeding species although they nest within the book's definition of the region only in the conifer or mixed forest of north-central to northwestern Minnesota, which isn't really a part of the Great Plains proper.

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There are over 1400 catalogued human pathogens, with approximately 62% classified as zoonotic (Taylor et al., 2001). Most evidence of direct transmission of pathogens to humans involves domestic and companion animals, whereas the reservoir for most zoonoses is wildlife; yet there are relatively few well-documented cases for the direct involvement of transmission from wildlife to humans (Kruse et al., 2004). In part, this absence of evidence reflects the mobility of wildlife, the difficulty accessing relevant samples, and the smaller number of studies focused on characterizing wildlife pathogens relative to the human and veterinary literature (McDiarmid, 1969; Davis et al., 1971; Hubalek, 2004).

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In order to determine potential definitive hosts of the digenetic trematode, Bolbophorus damnificus, two American White Pelicans (Pelecanus erythrorhynchos), two Double-crested Cormorants (Phalacrocorax auritus), two Great Blue Herons (Ardea herodias), and two Great Egrets (Ardea alba) were captured, treated with praziquantel, and fed channel catfish (Ictalurus punctatus) infected with B. damnificus metacercariae. Patent infections of B. damnificus, which developed in both American White Pelicans at 3 days post-infection, were confirmed by the presence of trematode ova in the feces. Mature B. damnificus trematodes were recovered from the intestines of both pelicans at 21 days post-infection, further confirming the establishment of infection. No evidence of B. damnificus infections was observed in the other bird species studied. This study provides further evidence that Double-crested Cormorants, Great Blue Herons, and Great Egrets do not serve as definitive hosts for B. damnificus.

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Many bird species are attracted to landfills which take domestic or putrescible waste. These sites provide a reliable, rich source of food which can attract large concentrations of birds. The birds may cause conflicts with human interest with respect to noise, birds carrying litter off site, possible transmission of pathogens in bird droppings and the potential for birdstrikes. In the UK there is an 8 mile safeguarding radius around an airfield, within which any planning applications must pass scrutiny from regulatory bodies to show they will not attract birds into the area and increase the birdstrike risk. Peckfield Landfill site near Leeds, West Yorkshire was chosen for a trial of a netting system designed to exclude birds from domestic waste landfills. The site was assessed for bird numbers before the trial, during the netting trial and after the net had been removed. A ScanCord net was installed for 6 weeks, during which time all household waste was tipped inside the net. Gull numbers decreased on the site from a mean of 1074 per hourly count to 29 per hourly count after two days. The gull numbers increased again after the net had been removed. Bird concentrations in the surroundings were also monitored to assess the effect of the net. Bird numbers in the immediate vicinity of the landfill site were higher than those further away. When the net was installed, the bird concentrations adjacent to the landfill site decreased. Corvids were not affected by the net as they fed on covered waste which was available outside the net throughout the trial. This shows that bird problems on a landfill site are complex, requiring a comprehensive policy of bird control. A supporting bird scaring system and clear operating policy for sites near to airports would be required.

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Fogging of ReJeX-iT7 TP-40 offers a very efficient method for the control and dispersal of nuisance birds from many diverse areas. The amount of the repellent is greatly reduced over any other control method. The method is direct and is independent of the activity of the birds. The applications with any fogger, thermal or mechanical, that can deliver droplets of less than 20 microns, can be manually or fully automated and pose only minimal risks to operators or animals. All birds that became a nuisance and safety problem in the hangars of TWA and AA at LaGuardia, and TWA warehouse at Newark Airport were successfully driven out by fogging ReJeX-iT7 TP-40 with a Curtis Dyna-Fog AGolden Eagle@ thermal fogger.

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In worldwide aviation operations, bird collisions with aircraft and ingestions into engine inlets present safety hazards and financial loss through equipment damage, loss of service and disruption to operations. The problem is encountered by all types of aircraft, both military and commercial. Modern aircraft engines have achieved a high level of reliability while manufacturers and users continually strive to further improve the safety record. A major safety concern today includes common-cause events which involve significant power loss on more than one engine. These are externally-inflicted occurrences, with the most frequent being encounters with flocks of birds. Most frequently these encounters occur during flight operations in the area on or near airports, near the ground instead of at cruise altitude conditions. This paper focuses on the increasing threat to aircraft and engines posed by the recorded growth in geese populations in North America. Service data show that goose strikes are increasing, especially in North America, consistent with the growing resident geese populations estimated by the United States Department of Agriculture (USDA). Airport managers, along with the governmental authorities, need to develop a strategy to address this large flocking bird issue. This paper also presents statistics on the overall status of the bird threat for birds of all sizes in North America relative to other geographic regions. Overall, the data shows that Canada and the USA have had marked improvements in controlling the threat from damaging birds - except for the increase in geese strikes. To reduce bird ingestion hazards, more aggressive corrective measures are needed in international air transport to reduce the chances of serious incidents or accidents from bird ingestion encounters. Air transport authorities must continue to take preventative and avoidance actions to counter the threat of birdstrikes to aircraft. The primary objective of this paper is to increase awareness of, and focus attention on, the safety hazards presented by large flocking birds such as geese. In the worst case, multiple engine power loss due to large bird ingestion could result in an off-airport forced landing accident. Hopefully, such awareness will prompt governmental regulatory agencies to address the hazards associated with growing populations of geese in North America.