Effects of habitat and climate change on blackbird populations

Global biodiversity loss is proceeding at an accelerating pace (Newbold et al. 2015, 2016) in large part due to land use and, climate change, and associated spread of disease and non-native species (Hobbs et al. 2006, Williams and Jackson 2007, Ellis 2011, Radeloff et al. 2015). Over the last century, U.S. average temperature has increased 0.7–1.1°C, leading to an increased frost-free season, more frequent and intense heat waves, and increased frequency and intensity of winter storms; mean precipitation has increased, with increases in heavy downpours (Melillo et al. 2014). The dominant land uses in the U.S. are lands devoted to forest (671 million acres; 30%), pasture/range (614 million acres, 27%), and agriculture (408 million acres, 18%) (Economic Research Service 2011). Martinuzzi et al. (2015) projected changes in land use to the middle of the 21st century and found that at least 11% of the U.S. land cover (an area larger than Texas) was expected to change cover class (Figure 1). At the same time, mean temperature is expected to further increase 1.1–1.7°C by mid-century and 2.2–3.9°C by end-of-century (Melillo et al. 2014). In this age of unprecedented human-induced environmental change, understanding the relationships of species to the habitat and climatic conditions they experience is crucial to conservation and management. Improved understanding of relationships with habitat and climate will better inform management decisions designed to reduce crop depredation caused by blackbirds.