Expansion of an exotic species and concomitant disease outbreaks: pigeon paramyxovirus in free-ranging Eurasian collared doves.

Eurasian collared doves (Streptopelia decaocto) have expanded their range across the United States since their introduction several decades ago. Recent mortality events in Eurasian collared doves in Arizona and Montana, USA, during the winter of 2009-2010 were the result of pigeon paramyxovirus (PPMV), a novel disease agent. The first instance of mortality by this emerging infectious disease in this species occurred in Florida in 2001 with subsequent disease events in 2006 and 2008.

Mite-filled cyst on a Brown-headed Cowbird (Molothrus ater) in Florida, USA.

A large, partly pedunculated mass on the scapular area of a wild-caught captive Brown-headed Cowbird (Molothrus ater) consisted of a multiloculated keratin cyst inhabited by a new species of harpirhynchid mite (Harpirhynchus quasimodo). The mass did not interfere with flight or behavior. This is the first record of such an infestation of cowbirds in Florida.

Survey for antibodies to infectious bursal disease virus serotype 2 in wild turkeys and Sandhill Cranes of Florida, USA.

Captive-reared Whooping Cranes (Grus americana) released into Florida for the resident reintroduction project experienced unusually high mortality and morbidity during the 1997-98 and 2001-02 release seasons. Exposure to infectious bursal disease virus (IBDV) serotype 2 as evidenced by seroconversion was suspected to be the factor that precipitated these mortality events. Very little is known about the incidence of IBD in wild bird populations.

Postmortem evaluation of reintroduced migratory whooping cranes in eastern North America.

Reintroduction of endangered Whooping Cranes (Grus americana) in eastern North America has successfully established a migratory population between Wisconsin and Florida. Eighty birds (47 males, 33 females) were released between 2001 and 2006, and all birds were tracked following release with satellite and/or VHF monitoring devices. By the end of 2006, 17 deaths (12 males, five females) were recorded from this population.

Effects of methylmercury exposure on the immune function of juvenile common loons (Gavia immer).

We conducted a dose-response laboratory study to quantify the level of exposure to dietary Hg, delivered as methylmercury chloride (CH3HgCl), that is associated with suppressed immune function in captive-reared common loon (Gavia immer) chicks. We used the phytohemagglutinin (PHA) skin test to assess T-lymphocyte function and the sheep red blood cell (SRBC) hemagglutination test to measure antibody-mediated immunity. The PHA stimulation index among chicks receiving dietary Hg treatment did not differ significantly from those of chicks on the control diet (p = 0.

Subchronic effects of methylmercury on plasma and organ biochemistries in great egret nestlings.

In recent years, high concentrations of mercury have been found in wading birds in Florida, USA. Great egret (Ardea alba) chicks (2 weeks old) were dosed orally daily with the equivalent of 0, 0.5, or 5 microg/g Hg as methylmercury chloride in the diet for up to 12 weeks.

Haemoproteus balearicae and other blood parasites of free-ranging Florida sandhill crane chicks.

We obtained blood smears from 114 Florida sandhill crane (Grus canadensis pratensis) chicks in Osceola and Lake Counties, Florida, USA, during 1998-2000. Leucocytozoon grusi was observed in 11 (10%) chicks; Haemoproteus antigonis was observed in eight (7%) chicks; and three (3%) chicks were infected with Haemoproteus balearicae. One chick infected with H.

A historical record of mercury contamination in Southern Florida (USA) as inferred from avian feather tissue.

During the late 1980s, the upper trophic-level biota of the Everglades (FL, USA) was recognized as being highly contaminated with mercury (Hg). However, the timing and pattern of that increase is poorly known, and no information is available about mercury contamination in Everglades wildlife prior to 1974. We measured methylmercury concentrations in feathers of white ibises (n = 33), great egrets (n = 7), anhingas (n = 21), and great blue herons (n = 12) from museum specimens collected from 1910 through 1980 and combined them with more recent feather samples collected from live birds (1985-2000, n = 98, 37, 49, and 7, respectively).

Epizootiology of Eustrongylides ignotus in Florida: transmission and development of larvae in intermediate hosts.

Under laboratory conditions, 2 modes of transmission of Eustrongylides ignotus (Nematoda: Dioctophymatoidea) to fish were identified. Eastern mosquitofish (Gambusia holbrooki) became infected after ingestion of either eggs of E. ignotus containing first-stage larvae or aquatic oligochaetes (Limnodrilus hoffmeisteri) containing third-stage larvae of E.

Burrowing fly larvae (Philornis porteri) associated with mortality of eastern bluebirds in Florida.

We investigated mortality among nestling eastern bluebirds (Sialia sialis) in Polk and Highlands counties, Florida (USA) in 1999-2001. At least six species of maggots from three families of muscoid flies, Calliphoridae, Sarcophagidae, and Muscidae were found associated with the nestlings. Philornis porteri, the only species of obligate bird parasite collected, was found in the contents of two nests, in the ear canal and the musculature of the jaw of one nestling, and in the abdominal subcutis of another.

Epizootiology of Eustrongylides ignotus in Florida: distribution, density, and natural infections in intermediate hosts.

A total of 63,451 fish, representing 39 species, was collected from 176 foraging sites used by ciconiiform wading birds in peninsular Florida (USA) and examined for larvae of Eustrongylides ignotus. Infected fish were identified from 30 (17%) of the sites, all of which had been altered by human disturbance such as removal of sediment to construct ditches and dikes, improve water flow, or increase storage capacity and had a history of receiving anthropogenic nutrients such as sewage effluent, urban runoff, or agricultural runoff. The mosquitofish (Gambusia holbrooki) and several species of sunfish (Centrarchidae) were the most important intermediate hosts.

Nineteenth century mercury: hazard to wading birds and cormorants of the Carson River, Nevada.

Contemporary mercury interest relates to atmospheric deposition, contaminated fish stocks and exposed fish-eating wildlife. The focus is on methylmercury (MeHg) even though most contamination is of inorganic (IoHg) origin. However, IoHg is readily methylated in aquatic systems to become more hazardous to vertebrates.

Sarcocystis meningoencephalitis in a northern gannet (Morus bassanus).

Sarcocystis sp. schizonts were found in the cerebellum of a northern gannet (Morus bassanus), exhibiting neurologic signs, found on the Florida (USA) east coast. Based upon molecular characterization of DNA isolated from the brain of the gannet, this Sarcocystis sp.

Wading birds as bioindicators of mercury contamination in Florida, USA: annual and geographic variation.

Mercury contamination in wetland biota is often dynamic, difficult to predict, and costly to track. In this paper, we present results from a six-year study of growing feathers of piscivorous birds as monitors of wetland Hg exposure in Florida, USA, wetlands. Between 1994 and 2000, we collected feathers of growing great egret (Ardea alba) nestlings from colonies in the freshwater Everglades of southern Florida, and during 1998, feathers were collected from chicks of both great egrets and white ibises (Eudocimus albus) at a variety of colonies throughout peninsular Florida.