Publications

The restrictive assumptions required by most available methods for estimating survival probabilities render them unsuitable for analyzing real banding data. A model is proposed which allows survival rates and recovery rates to vary with the calendar year, and also allows juveniles to have rates different from adults. In addition to survival rates and recovery rates, the differential vulnerability

The Everglade Kite (Rostrhamus sociabilis plumbeus) of Florida has been called snail hawk or snail kite because it was thought to feed exclusively on the soft parts of the freshwater apple snail (Pomacea paludosa) (Nicholson 1926, Howell 1932, Bent 1937, Snyder and Snyder 1969). Furthermore, the other three subspecies of this wide-ranging Neotropical raptor (Friedmann 1950) are known to feed only

Food supply has been acknowledged as one of eight major external factors regulating the sexual cycles of birds (Marshall 1961). Several hypotheses have been advanced to explain the role of food supply as an ultimate factor regulating breeding (Marshall 1951; Lack 1954, 1968; Wynne-Edwards 1962; and others). Another potential influence of food is its being a proximate stimulus to breeding. When cer

No abstract available.

No abstract available.

No abstract available.

The production characteristics of hot-water geothermal wells which flash to steam-water mixtures in the cased part of the hole were-analyzed. The flashing flow is assumed to be isenthalpic and, for purposes of calculating pressure drop, a finely dispersed mixture of equal average velocity. Water flow in the aquifer is treated using steady, radial Darcy flow. Calculations for a typical geothermal w

Food habits of breeding pintails (Anas acuta) were studied relative to sex, land use, and reproductive condition during the spring and summer of 1969, 1970, and 1971 in eastern North Dakota. Hens and drakes, respectively, consumed 79.2 percent and 30.0 percent animal matter on nontilled wetlands and consumed 16.6 percent and 1.1 percent animal matter on tilled wetlands. Aquatic dipterans (primaril

Young nestling Cooper?s Hawks peck vigorously at red objects but do not peck at yellow objects. The significance of this response is discussed in relation to developmental changes in iris coloration in adult hawks.

No abstract available.

A procedure for the determination of 3-mftuormethyl-4-nitrophenol (TFM) in fish tissues is described. Homogenized tissues are extracted with hexane-ethyl ether; the extract is cleaned up by partitioning the TFM from the extracting solvent into O.IN NaOB, acidifying the aqueous solution, and partitioning again with hexaneethyl ether. The TFM is methylated with diazomethane and analyzed by gas-liqui

The U.S. Geological Survey conducts repeated geodimeter surveys of trilateration networks in central California in order to study the processes of slip and strain accumulation along the San Andreas fault. The precision of distance measurement is described by a standard deviation σ = (a2+ b2L2)12 where a = 3mm, b = 2 · 10−7, and L is the line length. Within the precision of measurement, no anomalou