The ability to maintain a (relatively) stable body temperature in a wide range of thermal environments by use of endogenous heat production is a unique feature of endotherms such as birds. Endothermy is acquired and regulated via various endocrine and molecular pathways, and ultimately allows wide aerial, aquatic, and terrestrial distribution in variable environments. However, due to our changing climate, birds are faced with potential new challenges for thermoregulation, such as more frequent extreme weather events, lower predictability of climate, and increasing mean temperature.
Following a decade of research on the environmental impacts of microplastics, a knowledge gap remains on the processes by which micro and nanoplastics pass across biological barriers, enter cells and are subject to biological mechanisms. Here we summarize available literature on the accumulation of microplastics and their associated contaminants in a variety of organisms including humans. Most data on the accumulation of microplastics in both field and lab studies are for marine invertebrates.
Globally, agriculture has intensified during the past 50 years due to increased mechanization, changes in the timing of farming operations, grassland conversion to cropland, and increased agrochemical inputs. Birds associated with farmlands and grasslands in North America have experienced severe declines over the last several decades, prompting the need for a comprehensive review of the drivers, mechanisms and magnitude of effects on bird populations.
