NOAA satellite data: a useful tool for macro inventory

This article discusses some of the demonstrated and potential uses of data from satellites with large fields of view and high frequency of coverage, such as NOAA AVHRR data and Nimbus-7 CZCS data. The use of such data is discussed for three types of applications: (a) stratification, (b) change detection, and (c) area estimation. It is concluded that such data have considerable promise as an aid to a variety of large-area inventory and monitoring tasks.     

PERFORMANCE AND PERSISTENCE OF GREEN FLUORESCENT PROTEIN （gfp） MARKED AZOTOBACTER CHROOCOCCUM IN STERILIZED AND UNSTERILIZED WHEAT RHIZOSPHERIC SOIL

ThepracticaluseofAzotobacterchroococcumasbiofertilizer hasbeenincreasinglyidentifiedinrecentyears.Oftentheefficacy ofthesebacteriaisassessedonthebasisofcropresponseswithout knowingthesurvival,persistenceandcompetitiveabilityofthein troducedstrain.Inoculat…     

Kinship, familiarity and social status modulate social learning about “micropredators” (biting flies) in deer mice

Animals can learn to recognize and respond to dangerous, threatening factors through either individual or social learning, whereby an individual learns and acquires the defensive behaviors and avoidance responses of another. Here we show that kinship, familiarity, and relative dominance of the interacting individuals affect social learning of defensive responses to micropredators in deer mice, Peromyscus maniculatus. Brief exposure of individual male deer mice to biting flies (stable fly, Stomoxys calcitrans) induced a decrease in pain sensitivity, or analgesia, and active self-burying avoidance responses. The defensive analgesic responses and their fear/anxiety/stress associated correlates facilitate the display of behavioral avoidance responses. Preparatory analgesia and avoidance responses were evident 1–3 days later when the mice were exposed to biting flies that were altered to be incapable of biting but were not displayed to similar-sized non-biting house flies. These anticipatory avoidance and analgesic responses to biting flies were also acquired through social learning—without direct individual aversive experience with biting flies. Fly-naive mice (observers) that witnessed other mice (demonstrators) being attacked by biting flies but themselves were not bitten did not display any avoidance responses. However, when exposed 1–3 days later to altered flies with biting mouth parts removed, the observers displayed socially acquired analgesic and self-burying avoidance responses. Observers whose demonstrators were either kin (siblings) and, or members of a familiar pair (kin or non-kin) displayed enhanced social learning of defensive responses. Also, within the familiar pairs, social status affected learning with subordinate observers displaying better social learning than dominant observers. These findings indicate that kinship, familiarity and social status modulate social learning of defensive responses to, and the recognition of, dangerous and threatening stimuli, likely including that of predators.Communicated by G. Wilkinson     

Sex ratios and intrasexual competition for mates in a sex-role reversed shorebird,Wilson's phalarope (Phalaropus tricolor)

Summary Operational sex ratio (OSR) was proposed by Emlen and Oring (1977) as an empirical measure of the intensity of sexual selection. Few studies, however, have examined the link between OSR and levels of intrasexual competition, which may influence selection. We studied the seasonal relationship between OSR and female-female competition for mates in Wilson's phalarope (Phalaropus tricolor), a sex-role reversed, non-territorial shorebird. Positive correlations between four measures of OSR (Scan Ratio, Day Ratio, Focal Ratio, and Chase Ratio) indicated seasonal changes in the availability of mates for females. Changes in mate availability resulted from the interaction between paternal care and female emancipation, asynchronous spring arrival schedules of the sexes (Reynolds et al. 1986), and the effect of clutch failure on renesting opportunities. Measures of intrasexual competition (courtship chases, percent males defended, rate and intensity of mate defense, and female-male proximity) varied significantly within and among years. Univariate and multivariate correlations indicated general agreement between measures of OSR and estimates of intrasexual competition. Our results suggest that OSR may provide a useful estimate of the opportunity for sexual selection, especially in species with matedefense mating systems.     

Sexual selection and spring arrival times of red-necked and Wilson's phalaropes

Summary Seasonal changes in sex ratios during a 4-year study of red-necked phalaropes and a 3-year study of Wilson's phalaropes showed that females preceded males to breeding and/or courtship areas. The degree to which females preceded males may have been constrained by harsh weather, as the arrival of red-necked phalaropes was synchronous in 1983, when spring was unusually late. Neither sex defended territories; females competed vigorously for direct access to males. These findings show that selection for sexually asynchronous arrival need not act through territoriality. We interpret early female arrival as an adaptation for obtaining mates and coclude that sexual selection may be an important determinant of arrival times in mate defense social systems.     

Waterbird Communities and Habitat Relationships in Coastal Pastures of Northern California

We examined waterbird assemblages (diversity, composition, and species' densities) in 20 pastures near Humboldt Bay, California, in relation to habitat characteristics (vegetation height, soil penetrability, water depth), abundance of invertebrates (worms and other invertebrates), and presence of livestock. From October 1991 to May 1992 we observed 29 species and 10,776 birds, most (78%) of which foraged. Nonrandom pasture use by birds resulted in a highly clumped spatial distribution (s²:{ovbar>x} ratio = 42.1). Habitat characteristics of pastures correlated with this nonrandom pattern: waterbird diversity and densities of three sandpiper species and one gull species correlated negatively ( r = −0.61 and r = −0.44 to −0.67, respectively) with vegetation height; densities of two plover species correlated negatively ( r = −0.39 and −0.45) with soil penetrability; and waterfowl densities correlated positively with water depth ( r = 0.97). Species composition varied among pastures. Wading birds used pastures with tall vegetation, shorebirds and gulls frequented short-grass pastures, and waterfowl used flooded pastures of waterbirds and their densities increased in association with livestock.In coastal areas where much intertidal habitat has been reclaimed as postureland, pastures offered valuable habitats to nonbreeding waterbirds. We suggest that grazing in coastal pastures can be used to provide a mosaic of vegetation heights, which would yield greater waterbird diversity as well as higher densities of some species.     

Bacteria and viruses — indicators of environmental changes occurring in estuaries

Microorganisms are useful indicators of alterations in the natural environment. As presently employed, however, “indicator organisms” such as fecal coliforms and total coliforms have severe limitations. Other organisms have been proposed in recent years as potential indicator organisms, viz. Streptococci, Clostridia, and pseudomonads. The indicator organism concept is reviewed and recommendations for future studies are made. In particular, detection, isolation, and identification of viruses, effects of pollutants on the natural microbial flora, and reevaluation of microbial indicators are critical areas requiring research.     

A comparison of taxon co-occurrence patterns for macro- and microorganisms

We examine co-occurrence patterns of microorganisms to evaluate community assembly "rules". We use methods previously applied to macroorganisms, both to evaluate their applicability to microorganisms and to allow comparison of co-occurrence patterns observed in microorganisms to those found in macroorganisms. We use a null model analysis of 124 incidence matrices from microbial communities, including bacteria, archaea, fungi, and algae, and we compare these results to previously published findings from a meta-analysis of almost 100 macroorganism data sets. We show that assemblages of microorganisms demonstrate nonrandom patterns of co-occurrence that are broadly similar to those found in assemblages of macroorganisms. These results suggest that some taxon co-occurrence patterns may be general characteristics of communities of organisms from all domains of life. We also find that co-occurrence in microbial communities does not vary among taxonomic groups or habitat types. However, we find that the degree of co-occurrence does vary among studies that use different methods to survey microbial communities. Finally, we discuss the potential effects of the undersampling of microbial communities on our results, as well as processes that may contribute to nonrandom patterns of co-occurrence in both macrobial and microbial communities such as competition, habitat filtering, historical effects, and neutral processes.