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Dynamic optimization was used to investigate the optimal defoliation of salt desert shrubs in north-western Utah. Management was formulated in the context of optimal stochastic control theory, with objective functions composed of discounted or time-averaged biomass yields. Climatic variability and community patterns of salt desert...

San Diego County, California is larger in area than 2 of the 50 states (combined), its geographic (and thus biological) diversity ranges from the seacoast across mountains of nearly 2,000 m elevation to extreme desert, it is the southwesternmost county of the contiguous U.S., and it is inhabited by dedicated...

Of in the 15 participating banding stations in Region Park V in the autumn of 1983, only Baltimore's Leakin Park was new. Two others that were active but not reported in 1982 rejoined us in 1983. Four of the 15 stations are home operations, 2 are on Federal land, 2...

No abstract available....

A total of 36 roost sites of the Snail Kite (Rostrhamus sociabilis) were studied in southern Florida, of which four (11%) were used regularly for 6 or more years. Major roosts were also used as nesting sites. All roosts were in flooded marshes and 33 (91.6%) were in stands of...

The need for accurate information in modelling depends on the objectives of the effort. but trustworthy data are essential for a model intended for use in the management of natural resources. This point is illustrated by referring to a recently published model of canvasback ducks. We demonstrate that several key...

The population status, reproductive success, and levels of environmental contaminants in brown pelicans (P. occidentalis) in Texas were studied from 1975 through 1981. Breeding populations increased from 18 pairs in 1975 to 57 pairs in 1981. All unhatched eggs salvaged for analyses of contaminant residues contained DDT metabolites. Mean DDE...

Midwinter inventories of total numbers, population-age ratios in the autumn, and estimates of the total numbers of and age ratios in hunter-killed birds were used to develop a population budget for Atlantic Brant - Lightbellied Brent Geese - Branta bernicla hrota for the period 1968-84. Substantial fluctuations in productivity and...

General goodness-of-fit tests for the Jolly-Seber model are proposed. These tests are based on conditional arguments using minimal sufficient statistics. The tests are shown to be of simple hypergeometric form so that a series of independent contingency table chi-square tests can be performed. The relationship of these...

Thirteen captive and one free-ranging white-tailed deer (Odocoileus virginianus) were immobilized one to six times each with ketamine hydrochloride and xylazine hydrochloride during winter and spring in northern Minnesota. Administration of 0.09 to 0.53 mg of yohimbine hydrochloride per kg IV after each trial reversed the immobilization. The deer raised...

The object of this study was to determine whether interspecific competition modified local geographic distribution, after taking into account the effect of habitat structure. The tendencies for 14 passerine birds to have positive or negative associations were examined, using 7861 sample points in seven native forests on the islands of...

To search for the existence of stability gradients in North American breeding land bird communities we operationally defined stability (after Jarvinen 1979) as year-to-year persistence in species composition and distribution of species abundances. From the census data for 174 study plots we derived nine indices that estimate the annual variability...

In 1981, we studied Caspian Terns (Sterna caspia) and Elegant Terns (S. elegans) nesting at the south end of San Diego Bay, California. Randomly collected Caspian Tern eggs contained signficantly (P < 0.05) higher mean concentrations of DDE (9.30 ppm) than did Elegant Tern eggs (3.79 ppm). DDE may have...

Autumnal attraction to man-made lighting causes heavy mortality in fledgling Hawaiian seabirds: Newell's Shearwater (Puffinus auricularis newelli), Dark-rumped Petrel (Pterodroma phaeopygia sandwichensis), and Band-rumped Storm-Petrel (Oceanodroma castro). These threatened, endangered, and rare species (respectively) approach and circle lights on their first flight from mountain nesting colonies on the island of...

No abstract available....

From 1970-1977, unhatched snail kite eggs and young that were found dead at nests in Florida were analyzed by gas chromatography for residues of organochlorine pollutants. The 1970 and 1974 material showed measurable amounts of p,p'-DDE, p,p'-DDD, p,p'-DDT, and dieldrin. Dieldrin and polychlorinated biphenyl (PCB) residues were less than 0.1...

No abstract available....

Distinguishing forested wetland from dry forest using aerial photographs is handicapped because photographs often do not reveal the presence of water below tree canopies. Radar images obtained by the Seasat satellite reveal forested wetland as highly reflective patterns on the coastal plain between Maryland and Florida. Seasat radar images may...

In the decade since research commenced with the Peregrine in Arizona, over 60 sites have been identified which historically or presently are occupied by breeding pairs. Productivity was determined for about 120 breeding attempts from 1975-85. Almost all sites, for which productivity information is available for two or more years,...

Telemetry techniques can be used to study the survival rates of animal populations and are particularly suitable for species or settings for which band recovery models are not. Statistical methods for estimating survival rates and parameters of survival distributions from observations of radio-tagged animals will be described. These methods have...

U. s. Fish and Wildlife Service research projects during the last 10 years in the Pacific Northwest resulted in the collecting of a sample egg from 35 Swainson's Hawk nests (Henny and Kaiser, 1979. Murrelet 60:2-5; Henny et al. 1984. Raptor Research 18:41-48). Pesticide residues, eggshell thickness, and reproductive...

Since 1982 when secondary. poisoning of Red-tailed Hawks (Buteo jamaicensis) was documented following the recommended use of famphur on cattle, the Patuxent Wildlife Research Center has tested for organophosphate (OP) poisoning in selected birds of prey found dead. This report documents the circumstances for a number of. cases where birds...