Aim: To study the gross, histopathological and clinico-pathological findings in cases of hyperplastic goitre in sub-adult captive- reared black stilts following their release on riverbeds in the south Canterbury region of New Zealand.
Methods: Necropsies were undertaken on the recovered carcasses of 48 black stilts over a 3-year period (1997-1999). The cause of death was determined, and thyroid glands were examined histopathologically and compared with those of free-living pied stilts. Concentrations of triiodothyronine (T3) and thyroxine (T4) in the serum of sub-adult and adult stilts were measured before and after iodine supplementation.
Results: The main causes of death of captive-reared black stilts following release were trauma, predation and starvation. An increase in size of the thyroid gland due to follicular hyperplasia and dilation was seen in all birds with intact thyroid glands (n=27). Dysplastic follicular changes such as epithelial desquamation, lipid deposition and haemorrhage were common in a large proportion of individuals with goitre. Dietary supplementation with iodine greatly improved survival rates in sub-adults following release, and significantly increased concentrations of T3 and T4 in serum.
Conclusions: Subclinical goitre due to thyroid hyperplasia and dysplasia was the cause of hypothyroidism and this contributed to the poor survival of released sub-adult black stilts raised in captivity. Iodine supplementation of the diet of captive adults and sub-adults resulted in increased concentrations of T3 and T4 in serum and improved survivability.
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http://dx.doi.org/10.1080/00480169.2008.36822 | DOI Listing |
While the impact of introduced predators is a widely acknowledged issue and key component of conservation considerations for endemic waterbird populations in the Hawaiian Islands, the impact of native predators on endemic, endangered waterbirds is not as frequently discussed or factored into recovery models. The Pueo (Hawaiian Short-eared Owl; ) is a subspecies of Short-eared Owl endemic to the Hawaiian Islands and is State-listed as Endangered on the island of O'ahu. The Ae'o (Hawaiian Stilt; ) is a subspecies of the Black-necked Stilt endemic to Hawai'i and is federally listed as Endangered throughout its range.
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Department of Biological Sciences, Clemson University, Clemson, SC 29631, USA.
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Department of Wildland Resources, Ecology Center Utah State University Logan Utah USA.
The number of ground-nesting ducks in the wetlands of Great Salt Lake, Utah has drastically decreased in the past few decades. A potential cause for this decline is the increase of predator species and their abundances, which has caused most nests to fail from depredation. Ground-nesting ducks may be able to reduce the risk of nest depredation by selecting nest sites where local physical structures or vegetation provides olfactory or visual concealment.
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Faculty of Health Sciences, Universidad Europea de Valencia, Paseo de la Alameda, 7, 46010 Valencia, Spain.
Despite more studies being carried out to know the impacts associated with plastic debris and much effort being spent on marine ecosystems, the impacts of plastics on terrestrial and freshwater species remain largely unknown. Here, we explored the presence of anthropogenic materials in nests of two wader species, the gull-billed tern (Gelochelidon nilotica) and the black-winged stilt (Himantopus himantopus), breeding on the inland salt lakes in the “La Mancha Húmeda” Biosphere Reserve, Central Spain. We revealed the presence of anthropogenic debris, mainly macroplastics (>5 mm), in 2.
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Biodiversity, Ecology and Genome Laboratory, Faculty of Sciences, Mohammed V University in Rabat, 10106 Rabat, Morocco.
Avian influenza (AI) is a zoonotic disease significant to both public and animal health, caused by influenza virus A, and affects domestic poultry, wild birds, and mammals including humans. Aquatic birds are considered the natural reservoir of this virus. In 2016, Morocco experienced the first occurrence of low pathogenic H9N2 avian influenza virus (AIV) in poultry; however, no cases were reported in wild birds.
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