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The Australian sea-lion, Neophoca cinerea, has a 17-18-month breeding cycle on islands off the west coast of Western Australia. Buller, North Fisherman and Beagle Is are the main pupping sites, with several very small colonies (n> 3) at the Abrolhos Is. The 4-5-month pupping seasons are synchronised at North Fisherman and Beagle Is, but the sea-lions from Buller I. breed one month later and those from the Abrolhos Is two months earlier. Pup production and pup mortality were highly variable between seasons over which observations were recorded: 129 pups were born at the main breeding sites in early 1988, the mortality in the first five months was 7.1%, whereas 181 pups were born in late 1989 of which 24.3% died. Pups remain in the vicinity of their natal islands for the first 4-5 months of life before leaving, perhaps on foraging trips, with their mothers. Most return to their natal island, although others haulout on islands up to 27 km away. Some male N. cinerea congregate in bachelor colonies on islands adjacent to the Perth metropolitan region during the non-breeding season and migrate up to 280 km north each breeding season. The status of the isolated, west-coast N. cinerea population is unknown. The current high level of human pressure on sea-lion terrestrial habitats and their food resources indicate a need for further monitoring of this species.

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The San Marcos River in Texas supports a wide diversity of aquatic organisms and provides critical habitat for eight endangered species. It is also a highly invaded ecosystem, with 48 documented introduced species. Several of these are invasive and known to negatively impact native species. Increasing pressure to control or eradicate invasive species exists to mitigate their impacts. Management programs can be controversial and, in some cases, have been delayed or stopped because of public opposition. People who have a vested interest in an invaded ecosystem, stakeholders, may be the most likely to express opposition or offer support for invasive species control. Understanding opinions can help guide educational outreach to gain public support for management programs. To assess stakeholder’s opinions of invasive species (defined as species that cause harm to the environment or human health), a survey instrument was distributed, and 335 completed surveys were analyzed. The majority of survey participants believed nonnative, invasive species should be controlled to conserve the environment (84.4%), where they damage native Texas species (75.9%), and in particular when they threaten rare Texas native species (89%). Proposed management methods influenced levels of support for invasive species control. Significant differences among demographic groups were found in membership in environmental organizations, knowledge of invasive species in the river, and sources of information on invasive species.

Genetic variation was evaluated in the federally endangered species Abronia macrocarpa (large-fruited sand-verbena), an herbaceous perennial restricted to deep sandy soils and endemic to three counties of east-central Texas. Seven of the ten known populations were sampled and analyzed using starch gel electrophoresis of eight enzymes coded by 18 interpretable loci. Duplicate gene expression was observed for four loci, suggesting polyploid ancestry for the lineage that includes A. macrocarpa. Values for estimators of genetic polymorphism within populations (ranges: P = 38.9%-61.1%, A = 1.7-2.1, H = 0.122-0.279) exceeded average values for seed plants (P = 34.2%, A = 1.53, H = 0.113). Genotype proportions at most loci in most populations were in Hardy-Weinberg equilibrium, consistent with obligate outcrossing previously documented for this species; exceptions could be attributed to population substructure. Values of F(ST) tended to be high, ranging from 0.021 to 0.481 for individual loci (mean F(ST) = 0.272), indicating substantial divergence and limited gene flow among populations, despite their close geographic proximity. Pairwise values of Nei's genetic identity between populations ranged from 0.799 to 0.975 and tended to be influenced by geographic proximity of population pairs. Collectively, these data suggest a long history of isolation among populations that have not been subjected to bottlenecks. Isolation of A. macrocarpa populations apparently results from the disjunct occurrence of suitable habitat and perhaps has been accentuated by human disturbance.

Surveys to detect the presence or absence of endangered species may not consistently cover an area, account for imperfect detection or consider that detection and species presence at sample units may change within a survey season. We evaluated a detection-nondetection survey method for the federally endangered golden-cheeked warbler (GCWA) Dendroica chrysoparia. Three study areas were selected across the breeding range of GCWA in central Texas. Within each area, 28-36 detection stations were placed 200 m apart. Each detection station was surveyed nine times during the breeding season in 2 consecutive years. Surveyors remained up to 8 min at each detection station recording GCWA detected by sight or sound. To assess the potential influence of environmental covariates (e.g. slope, aspect, canopy cover, study area) on detection and occupancy and possible changes in occupancy and detection probabilities within breeding seasons, 30 models were analyzed. Using information-theoretic model selection procedures, we found that detection probabilities and occupancy varied among study areas and within breeding seasons. Detection probabilities ranged from 0.20 to 0.80 and occupancy ranged from 0.56 to 0.95. Because study areas with high detection probabilities had high occupancy, a conservative survey effort (erred towards too much surveying) was estimated using the lowest detection probability. We determined that nine surveys of 35 stations were needed to have estimates of occupancy with coefficients of variation 20%. Our survey evaluation evidently captured the key environmental variable that influenced bird detection (GCWA density) and accommodated the changes in GCWA distribution throughout the breeding season.

The purpose of this study was to determine college students’ understanding of invasive species and their support for plant and animal pest control and eradication methods. Surveys were administered at a university and community college in Texas in biology and agriculture departments. A total of 533 respondents participated in the study. Most students said they were not part of any type of environmental organization and felt they were not very informed about invasive species issues. More students reported learning about invasive species in high school than in college courses. The average score on knowledge questions related to invasive and native plants and animals was 32%. Most students underestimated the negative impact of invasive species but many were aware of costs to manage those species. Reliable reported sources of information included environmental organizations, college courses, and the Internet. Pearson product-moment correlations showed positive relationships between students who had college class instruction regarding invasive species and positive attitudes toward management of invasive species. Positive relationships were also found between instruction and an awareness of invasive plants or animals. Respondents who were knowledgeable of invasive species in the community had more positive attitudes toward the management of invasive species. In demographic comparisons, differences were found with males, upperclassmen, and those identifying as Caucasian or other having more knowledge of invasive species and more positive attitudes toward their management.