Monitoring long-term trends in population size is important for species' conservation assessments. However, it may be unfeasible for rare species, for which past records are typically sparse. In this study, the potential of birding trip reports as an underappreciated source of biological information to monitor rare species was investigated.

The carotenoid-based ornaments displayed by many birds often play key roles in social and sexual signalling, revealing information about individual quality. Understanding the mechanisms of coloured trait production and maintenance requires an accurate description of their composition and of the physiological pathways involved in their expression. Carotenoid-based colouration has been extensively studied in birds, but such information is often lacking for coloured integuments other than...

Organochlorine (OC) pesticides and the more persistent polychlorinated biphenyls (PCBs) have well-established dose-dependent toxicities to birds, fish and mammals in experimental studies, but the actual impact of OC pollutants on European marine top predators remains unknown. Here we show that several cetacean species have very high mean blubber PCB concentrations likely to cause population declines and suppress population recovery.

Recent studies suggest that direct mortality and physiological effects caused by pollutants are major contributing factors to global amphibian decline. This study shows how sublethal concentrations of pollutants can disrupt the ability of amphibian larvae to recognize their natural predators, hence increasing the risk of predation in the populations.

The importance of waterbirds as vectors of aliens has been recognized since Darwin's time, yet research by pioneers has been forgotten during the development of modern invasion biology, which tends to overlook this means of dispersal. Waterbirds are ignored in databases of alien species and invasion pathways, making management and prevention of invasions more difficult. This article summarizes studies that provide empirical evidence for the dispersal of alien plants and invertebrates by...