Showing papers on "Nycticorax published in 2002"

Prevalence of blood parasites in Japanese wild birds.

Abstract: The prevalence of blood parasites was investigated in 701 Japanese wild birds for 13 years from January, 1988 to March, 2001. Most of the injured or sick birds were caught in the suburbs of Kobe City, Hyogo Prefecture and brought to the zoo for clinical care. Among all the birds examined, 10.6% were infected with hematozoa belonging to three genera as Plasmodium (1.7% of the samples), Haemoproteus (5.1% of the samples) and Leucocytozoon (4.6% of the samples), and two birds (0.29% of the samples), a Japanese grosbeak (Coccothraustes personatus) and a dusky thrush (Turdus naumanni), were infected with microfilariae. Mixed infection with Leucocytozoon sp. and Haemoproteus sp. was observed in 6 individuals of 4 species and that with Leucocytozoon sp. and microfilariae was observed in 2 individuals of 2 species of bird. Relatively high positive rates were 75%(3/4) in the scops owl (Otus scops), 71.4% (10/14) in the ural owl (Strix uralensis), 57.7% (15/26) in the jungle crow (Corvus macrorhynchos), 57.1% (4/7) in the black-tailed gull (Larus crassirostris), 55.6% (5/9) in the brown hawk owl (Ninox scutulata), 41% (16/39) in the carrion crow (Corvus corone) and 24.1% (7/29) in the night heron (Nycticorax nicticorax).

Risk to breeding success of Ardeids by contaminants in Hong Kong: evidence from trace metals in feathers.

Abstract: The feathers of two Ardeid species, the Little Egret (Egretta garzetta) and the Black-crowned Night Heron (Nycticorax nycticorax) were collected from six egretries and two egretries respectively, located in different areas in the New Territories of Hong Kong, including the Mai Po Marshes (within a Ramsar site). These feathers were digested and concentrations (µg/g dry weight) of copper (4.6–19.4), iron (8.1–641.3), manganese (0.4–19.4), zinc (51.3–183.5), lead (0.1–5.1), cadmium (0.01–0.15), chromium (0.06–1.7) and mercury (0.0–7.1) were determined by ICP-AES, ICP-MS and CVAAS. The levels of manganese, mercury and lead found were equal to or less than the concentrations found in previous investigations, reflecting a slight downward trend most apparent with lead. As a general rule, the levels of lead and mercury were higher in the egretries close to the polluted Deep Bay. A probabilistic risk assessment of the possible adverse effects on the breeding success of the Little Egret was carried out with respect to mercury, lead and cadmium. It was concluded that mercury (0.5–7.1 µg/g dry weight feathers) probably has had adverse effects at the Au Tau egretry of the Little Egrets, but there was no evidence of adverse effects at other egretries. The probabilistic analysis also indicated a low likelihood of adverse effects of mercury on the breeding of the Black-crowned Night Herons at A Chau (0.3–1.2 µg/g) and Mai Po Village (0.0–1.4 µg/g). The evidence for the effects of lead and cadmium was limited but suggested there may possibly be adverse effects with lead but not cadmium.

Relocation of a Large Black-crowned Night Heron Colony in Southern California

Abstract: The Port of Long Beach is currently developing the former U.S. Naval Station Long Beach into a marine container terminal. When the Naval Station was operational, a large Black-crowned Night Heron (Nycticorax nycticorax) colony (up to 500 pairs) occupied mature Indian Laurel (Ficus microcarpa) and Olive (Olea europaea) trees that lined the Station streets. Although Black-crowned Night Herons are abundant throughout southern California, a nesting colony of this size is unusual. As part of an agreement with the U.S. Fish and Wildlife Service under the Migratory Bird Treaty Act, the Port agreed to relocate the colony prior to construction of the terminal. In 1999, 50 mature Indian Laurel, Olive, and Paperbark (Melaleuca sp.) trees were boxed and transported to a location in the port approximately two km from the original site. The relocated trees supplemented approximately 70 trees and bushes already at the location, formerly a park. Black-crowned Night Heron decoys were placed in the trees, heron vo...

Population of Waterbirds in the Breeding Colony at Khuan Khi Sian, Thailand's First Ramsar Site

Abstract: This study investigated the species composition, population size and population fluctuation of waterbirds in Melaleuca swamp forest at Khuan Khi Sian, Thale Noi Non-hunting Area, Phatthalung Province, southern Thailand. The study was conducted from April 1998 to March 1999. The number of waterbirds was counted monthly and some envi- ronmental factors were also observed. It was found that the Melaleuca swamp forest was a breeding site of five species of waterbirds, consisting of Phalacrocorax niger, Ardea purpurea, Bubulcus ibis, Egretta garzetta and Nycticorax nycticorax. This area was also served as a night roosting site for a rare migratory species, Threskiornis melanocephalus from April to July. The population density of waterbirds in the breeding colony greatly fluctuated throughout the year, but peaked in May when the number reached 20,430 individuals. The lowest number was 136 in September. Of all the waterbirds, only P. niger and A. purpurea used this breeding area throughout the year. Considering environmental factors, the number of B. ibis, N. nycticorax and T. melanocephalus showed correlations with mean temperature, relative humidity and total rainfall.

Breeding ecology of the four herons

Abstract: The breeding ecology of the four herons (Ardeola bacchus, Bubulcus ibis, Egretta garzetta, Nycticorax nycticorax), such as ingression time, breeding behavior and nestling growth were observed and studied from 1999 to 2001. The results indicate that the numbers of herons are increasing every year. The species of heron were raised from two to four in this region. The community of four heron can build nests, look for food and live with its habits in harmony of population. The four heron differ partly in food components. The food components of Black-crowned Night Heron chiefly consist of frog and fish. Those of Little Egret are mainly composed of fish and crustacean. Cattle Egret live on insects and frog, Chinese Pond Heron on fish. There is a negative correlation between the weight growth and the adult size of the four young of heron. Analysis of the growth curve shows that Chinese Pond Heron and Cattle Egret have faster growth rate than the other two.