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At least 1,549 records · Page 86Linked to original sources
USGS1998

Saker falcon research and conservation efforts in Mongolia, 1997

This past summer. our small field team followed a 4000 km route through central and eastern Mongolia. Even though there was a population crash underway for picas (Ochotona sp.) and voles (Microtus sp.). we found 38 new saker nests and visited 60 eyries found in previous years. Many of the former eyries were unoccupied. Others were occupied but without young. Productivity was good at eyries with large young. and southeastern Mongolia seemed unaffected by food shortages. The main goal for 1997 was to create new eyries and enlarge. stabilise. or otherwise alter marginal eyries. \Ve created 65 eyries as follows: 8 on wooden powerlines or telephone supports, 8 on metal power line towers, 3 in trees, 3 on boulders, 11 on cliffs, 17 on abandoned buildings, 9 on metal geological survey towers, and 6 on miscellaneous structures. \Ve also enlarged or repaired three establishedeyries and did minor repairs on several others. Lesser accomplishments include what may be the first observation of siblicide for the saker falcon (please contact us immediately if you have other records of sakerchicks attacking or killing their nest mates) and the description of a new saker flight display. We also documented an unusual golden eagle eyrie containing the remains of nearly 30 foxes, several predatory birds, and a number of gazelle. In 1998. we plan to return to Mongolia to see how many of our 'fake eyries' attracted falcons. Our work in 1997 was supported by Mr. Howell. another philanthropist (anonymous) and the Institute of Raptor Studies.

Falco↗
USGS1985

Atlantic Flyway review: Region V: Patuxent Wildlife Research Center, Laurel, Prince Georges County, MD (390-0764)

This was my 4th year of banding in a powerline right-of-way that is specially managed to encourage growth of dense scrub. Nets were run for 2 to 3 hours each morning, because activity dropped off rapidly after the sun hit the nets. I banded on 79 days, from 1 August to 22 November. Frost continues to be a problem late in the season; the frostpocket effect of the stream valley and the lack of vegetative cover over the nets result in frozen nets on more mornings than would be expected. Warblers continued to dominate, with as many as 16 species in one day and a season total of 33 plus a Brewster's hybrid. Net-hours declined from 8506 to 7672 because I discontinued six of my least productive nets; this change accounted for much of the increase in birds per 100 net-hours (Table 1). Overall effort was comparable to that of 1982.

Maryland↗
USGS2000

Seasonal distribution of bird populations at the Patuxent Research Refuge

High concentrations of mercury from past mining activities have accumulated in the food chain of fish-eating birds nesting along the mid to lower Carson River. Activities of nine plasma and tissue enzymes, and concentrations of other plasma and tissue constituents were measured for black-crowned night-heron, Nycticorax nycticorax, (BCNH) and snowy egret, Egretta thula, (SE) nestlings from two high mercury sites and one low mercury site. Geometric mean blood Hg concentrations for BCNHs at the high mercury sites were 2.6 and 2.8 ppm (ww) and 0.6 ppm at the low mercury site. Blood concentrations for SEs were 3.6 and 1.9 ppm at the high mercury sites and 0.7 ppm at the low mercury site. In BCNHs plasma glutathione peroxidase (GSH peroxidase) activity was lower in both high mercury sites relative to the low mercury site. Butyryl cholinesterase (BuChe), ALT, glutathione reductase (GSSG-reductase) and LDH-L activities were lower in one high mercury site. In SEs significant differences were lower BuChe and LDH-L, but elevated GGT activities. Evidence of renal stress in both species at high mercury sites included increased plasma uric acid, blood urea nitrogen, and creatinine concentrations as well as oxidative stress in the kidney tissue itself where oxidized glutathione increased. A number of the mercury site-related effects, including decreased plasma GSH-peroxidase and hepatic G-6-PDH activities, higher GSSG-reductase activity, and lower hepatic concentrations of reduced thiols have been reported in methylmercury feeding studies with great egrets and mallards. These findings suggest the utility of herons and egrets for monitoring mercury sites.

Society of Environmental Toxicology and Chemistry,↗