Superresolution imaging with fluorescent dyes

With the combination of climate change and human encroachment on the territory of endangered species, information about what and where animals eat and how this is changing over time can help guide conservation efforts. Thure Cerling et al. compiled a 6-year record of nitrogen, carbon, oxygen, and hydrogen in the diet of a family of 4 Kenyan elephants by analyzing the isotopic content of the elephants’ tail hair. The authors tracked the elephants’ precise location throughout the study by using GPS collars. Carbon isotopes in the hair were strongly correlated within the family and varied in phase with regional vegetation; hydrogen isotopes kept pace with vegetation and rainfall fluctuations. The authors found that the elephants ate more C4 plants, such as grasses, during the rainy season (C4 plants tend to have slightly higher levels of 13C than C3 plants). The elephants ate few C4 plants during 1 rainy season that coincided with the animals’ departure from their national park into a region heavily grazed by cattle. The episode highlights the competition between cattle and elephants for pasture, the authors say. — K.M.