The status of the world's land and marine mammals: diversity, threat, and knowledge.

Knowledge of mammalian diversity is still surprisingly disparate, both regionally and taxonomically. Here, we present a comprehensive assessment of the conservation status and distribution of the world's mammals. Data, compiled by 1700+ experts, cover all 5487 species, including marine mammals. Global macroecological patterns are very different for land and marine species but suggest common mechanisms driving diversity and endemism across systems. Compared with land species, threat levels are higher among marine mammals, driven by different processes (accidental mortality and pollution, rather than habitat loss), and are spatially distinct (peaking in northern oceans, rather than in Southeast Asia). Marine mammals are also disproportionately poorly known. These data are made freely available to support further scientific developments and conservation action.

Addressing data deficiency in classifying extinction risk: a case study of a radiation of Bignoniaceae from Madagascar.

Of the roughly 12,000 known plant species in Madagascar only 3% are found in the IUCN (World Conservation Union) Red List of Threatened Species. We assigned preliminary IUCN categories of threat to the species of a comparatively well-known tribe, Coleeae (Bignoniaceae), which comprises an endemic, species-rich radiation in Madagascar Because the IUCN Red List Categories and Criteria 3.1 discourage the use of the data-deficient category, we developed a novel method for differentiating between range-limited species and poorly sampled species. We used the Missouri Botanical Garden (MBG) gazetteer to determine where other collection efforts had taken place. We drew buffers around each Coleeae locality and determined how many times the surrounding area bad been visited since the last sighting of the specimens by intersecting the buffers with all known botanical localities from the MBG gazetteer We determined that at least 54% of the Coleeae species are threatened with extinction. Assignments of species to this category were often due to predicted future decline within their current area of occupancy and their lack of inclusion within the protected-area network (only 42% of species are known to occur in protected areas). Three species were presumed extinct, and an additional 12 have not been seen in decades. Among the species threatened with extinction, we "rescued" six of them from the data-deficient category by considering both the sample dates and localities of places where they occurred in relation to additional collections that took place in the immediate area. Due to their recent discovery, 15 species remained in the data-deficient category If Coleeae is representative of the Malagasy flora, or at least of other endemic-radiated plant groups, then species loss in Madagascar may be even more extreme than is realized.

Corticosteroids as potential mechanism regulating variability in reproductive success in monogamous oldfield mice (Peromyscus polionotus).

Male and female mammals undergo profound hormonal changes during pregnancy, some of which are sufficiently dramatic to influence offspring survival. In order to understand the proximate mechanisms regulating the variability in reproductive success within and between individuals, we monitored changes in fecal corticosteroid concentrations over the reproductive cycle in male and female oldfield mice (Peromyscus polionotus subgriseus) to test whether corticosteroid concentrations during pregnancy were associated with offspring survival. In females that successfully raised litters to weaning, fecal corticosteroid concentrations were low until mid-gestation and increased significantly towards term; in females that did not raise their pups to weaning, fecal corticosteroid concentrations were significantly higher at mid-gestation, and remained high until late gestation. The difference in fecal corticosteroid concentrations at mid-gestation between successful and unsuccessful females can be explained by the fact that successful females were lactating. Lactation has been associated with a down-regulation of the hypothalamic-pituitary-adrenal (HPA) axis and, accordingly, a decrease in plasma corticosterone (CORT) in several species, including humans. Males that successfully raised their litters had low fecal corticosteroid concentrations throughout their partner's pregnancy. Unsuccessful males, however, had significantly higher fecal corticosteroid concentrations at term than males that raised their pups to weaning. While these preliminary data require further investigation, we suggest that pre-partum fecal corticosteroid concentrations in males were responsible for the variability in reproductive success.