We provide a detailed description of and a staging table that portrays the ontogeny of the Great Basin spadefoot (Scaphiopus intermontanus Cope) from the just-hatched larva through the adult. We concentrate on the development of external morphological characters as observed in individuals raised under controlled laboratory conditions. We suggest that our staging table, besides providing greater detail, is more appropriate than a generalized staging table for describing the ontogeny of species within Scaphiopus. Also, unlike other staging tables, we delineate stage bound- aries. We recommend the use of stage boundary criteria for the construction of all future staging tables. Our findings indicate that some aspects of Scaphiopus ontogeny may be unique. Unlike other anuran larvae with sinistral spiracles, the operculum in S. intermontanus does not pass through a stage in which there are two separate openings. Other features, such as mouthpart characteristics, may be useful for intrageneric larval identification; however, we show that at least the labial tooth-row formula variation is affected by both rearing temperature and geographic origin of the specimen sample. Finally, rearing conditions possibly affect the timing of certain developmental events in S. intermontanus. Specifically, the timing of hindlimb differentiation seems to be labile relative to when differentiation occurs in other morphological features. table DETAILED DESCRIPTIONS of the ontog- eny of embryonic, larval, metamorphic, and postmetamorphic frogs (Anura) are important for understanding the general pattern(s) of development of representa- tive taxa and, by comparisons of different patterns, for resolving questions about sys- tematic relationships. For anurans, staging tables are a condensed way of describing ontogenetic changes. In a review of the lit- erature, Fox (1984:30) indicated that of the few thousand known species of anu- rans there are complete staging tables- fertilized egg through the completion of metamorphosis-for fewer than 20 spe- cies. Just et al. (1981: their Table 3) com- pared the staging tables of a number of these species. Most of the tables that have been constructed are for species contained in the genera Bufo and Rana. Two of the most detailed tables, for the African

Growing concern over the health of the world's environment necessitates development of methods to monitor environmental changes over time. Various proposals involving ''literally'' thousands of useful ecological indicators (Cairns and McCormick 1992) have been published over the past two or three decades. Hinds (1984) and Cairns and McCormick (1992) discuss several aspects of such proposals, including the theoretical foundations for the use of indicators in ecosystem-based monitoring.Sampling of animals often requires a choice between killing individuals in the field to allow measurement, or using an indirect or correlation-based non-destructive sampling technique. The latter is preferred usually for long-term monitoring programs. Sampling of feathers to determine metal concentrations in tropical Pacific Rim birds, including herons, was reported by Burger (1993), Burger and Gochfeld (1991, 1993), and Burger et al. (1992, 1993). While collection of feathers did not harm the birds, the feathers still had to be plucked from the birds. We report a method that does not involve disturbing the birds.Great blue herons (Ardea herodius) feed at the top of a diverse but reasonably well understood food web. The birds are colonial during their reproductive season, and gather into identifiable, replicable, and annually repeated groups, using the same nests (usually in trees) for years at a time. Herons maintain nests free of regurgitated prey parts and nestling fecal materials by discarding detritus and fecal sacs over the nest edge. This behavior produces a ''rain'' of fecal matter including identifiable discarded or undigested items (e.g., bones) that reflect the food on which herons prey. Collecting this material provides a quantifiable estimate of contaminants in the food web (Fitzner et al. 1982) and makes the heron a prime sampling target (Fitzner et al. 1982; Carlile and Fitzner 1983; Hinds 1983).We discuss here the results of a two-year study designed to determine the relationship between heavy metal residues in heron fecal castings and those in heron tissues from the same colonies. We also evaluated whether analysis of heron excrement was a reliable indication of heavy metals in the environment.

The US Department of Energy`s (DOE) Hanford Site has been placed on the National Priorities List, which requires that it be remediated under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) or Superfund. Potentially contaminated areas of the Hanford Site were grouped into operable units, and detailed characterization and investigation plans were formulated. The DOE Richland Operations Office requested Westinghouse Hanford Company (WHC) to conduct a biological assessment of the potential impact of these characterization activities on the threatened, endangered, and sensitive wildlife species of the Hanford Site. Additional direction for WHC compliances with wildlife protection can be found in the Environmental Compliance Manual. This document is intended to meet these requirements, in part, for the CERCLA characterization activities, as well as for other work comparable in scope. This report documents the biological assessment and describes the pertinent components of the Hanford Site as well as the planned characterization activities. Also provided are accounts of endangered, threatened, and federal candidate wildlife species on the Hanford Site and information as to how human disturbances can affect these species. Potential effects of the characterization activities are described with recommendations for mitigation measures.

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An ecological survey was conducted on M-Field, at the Edgewood Area, Aberdeen Proving Ground, Maryland. M-Field is used routinely to test army smokes and obscurants, including brass flakes, carbon fibers, and fog oils. The field has been used for testing purposes for the past 40 years, but little documented history is available. Under current environmental regulations, the test field must be assessed periodically to document the presence or potential use of the area by threatened and endangered species. The M-Field area is approximately 370 acres and is part of the US Army`s Edgewood Area at Aberdeen Proving Ground in Harford County, Maryland. The grass-covered field is primarily lowlands with elevations from about 1.0 to 8 m above sea level, and several buildings and structures are present on the field. The ecological assessment of M-Field was conducted in three stages, beginning with a preliminary site visit in May to assess sampling requirements. Two field site visits were made June 3--7, and August 12--15, 1991, to identify the biota existing on the site. Data were gathered on vegetation, small mammals, invertebrates, birds, large mammals, amphibians, and reptiles.

Overall, the nesting population of Great Basin Canada geese (Branta canadensis moffitti) on the Hanford Site in southcentral Washington State is doing well and appears to be increasing. The average annual total nests for the period 1981 through 1990 was 215 nests, which is slightly above the average reported for the period 1950 through 1970. The nesting population has shifted its nucleus from upriver islands (1--10) to the lower river islands (11--20) with over 70% of the present-day nesting occurring on Islands 17, 18, 19, 20. The annual percent-successful nests from 1981 through 1990 was 80%. This is above the 71% reported for 1950 to 1970, but is below the 82% reported for 1971 to 1980. Average annual clutch size for 1981 to 1990 was 6.05, which is above the 1971-to-1980 average of 5.6 and the 1950-to-70 average of 5.5. Next desertions for 1981 to 1990 averaged 8%. This rate is well below the 14% reported for 1950 to 1970. Predators were responsible for an annual predation rate of 9% from 1981 to 1990. This is below the 1950-to-1970 annual average predation rate of 14%. Flooding losses to nests were low during the 1980s, except for 1989 and 1990 whenmore » 6% and 9% of the total nests, respectively, were destroyed by flooding. 9 refs., 4 figs., 1 tab.« less

A baseline census was conducted from October 1987 to Janurary 1988 on the property identified for possible expansion of the Yakima Firing Center. These studies provide general descriptions of the major plant communities presentand animal inhabitants during the late fall and winter study period. A vegetation map derived from a combination of onsite surveillance and remotely sensed imagery is also provided as part of this report. Through January 1988, 13 wildlife species of special interest to state and federal agencies, in addition to ducks and geese, were observed on the proposed expansion area. Then raptorial bird species were observed in the area, including bald eagles, golden eagles, and prairie falcons. Upland game bird species, such as sage grouse, California quail, chuckars, and gray (Hungarian) partridge were present. Loggerhead shrikes, a species of special interest, were also observed on the site. Estimates of waterfowl abundance are included for the Priest Rapids Pool of the Columbia River, which includes the proposed river crossing sites. The number of waterfowl on the proposed crossing areas were comparatively low during the winter of 1986 to 1987 and high in 1987 to 1988. Bald eagles ad common loons were observed on the crossing areas. Six smallmore » mammal species were captured during this study period;one, the sagebrush vole, is a species of special interest. Two large animal species, mule deer and elk, were noted on the site. Beaver were the only furbearig animals noted to date. Rainbow trout were the only fish species collected within the proposed northern expansion area. The distribution of fall chinook salmon spawning areas was documented within the proposed river crossing areas. 3 refs., 7 figs., 3 tabs.« less

Ferruginous hawks were an uncommon nesting raptor on the US DOE Hanford Site prior to 1987, with only one or two pairs nesting each year. In 1987, four pair were found nesting on transmission towers. In 1988, seven pairs were observed nesting on the towers. This recent increase in nesting pairs may correspond to an acceptance phenomena related to age of the transmission towers. The increase may be due to an overall increase in the population of ferruginous hawks in Washington. 12 refs., 4 figs.

The information in this interim report will be used to design future environmental monitoring plans and assess impacts related to Basalt Waste Isolation Project (BWIP) activities. New reports will be issued as more data become available. Five study locations were established to study cold-blooded vertebrates in the vicinity of the proposed Reference Repository Location. Four study sites were in shrub-dominated stands of vegetation; the other site was devoid of shrubs because of a range fire in 1984. The side-blotched lizard (Uta stansburiana), trapped in four of the five plots, was the only lizard species captured. It was not trapped in the one plot dominated by spiny hopsage (Grayia spinosa) shrubs. It is uncertain whether the side-blotched lizard is absent from this particular vegetation type, or if the population is too low to have been detected in the relatively short time span of the investigation. Two species of snakes were captured, gopher snakes (Pituophis melanoleucus) and green racers (Coluber constrictor mormon). The number of snakes captured was too small to detect any distributional pattern in space or time. Studies are continuing. 4 refs., 9 figs., 3 tabs.

In July of 1980, while examining nestling Swainsoh's Hawks (Buteo swainsoni), we found that 12 of the 15 nestlings we studied were parasitized by C. hemapterus. The flies occurred in groups of 3 to 5 and were found only in the axillary region of the hawks. No flies were attached and on being disturbed they moved from the bare axillary region to nearby feathered areas. The exact nature of the diet ofC. hemapterus is unknown. Noller (1920) reports that the fly sucks blood from its host, while Hendel (1928) felt that Carnus feeds most probably on skin secretions. We observed dried blood spots on the hawks axillary region which is supportive of Noller's (1920) claim. The true diet of the fly is presently in question, but the fly could act as a vector of certain avian blood parasites. Our findings are of interest, since few records have been reported for C. hemapterus in non-cavity nesting birds or from long-distance migrants like the Swainsoh's Hawk. Our report is also the first record of this dipteran parasite on the Swainsoh's Hawk.