As species rapidly adapt to altered landscapes and a warming climate, scientists and stakeholders need new techniques to monitor ecological responses and plan future conservation efforts. Writing in BioScience, Stephen McCormick of the US Geological Survey and Michael Romero of Tufts University describe the emerging field of conservation endocrinology and its growing role in addressing the effects of environmental change. The authors argue that, bolstered by the development of new field-sampling techniques, researchers working in this area are poised to make substantial contributions to the wider field of conservation biology.