data rates of energy accumulation

There are seven columns: 1. “subsp”: This is a factor with two levels. "leu" says that the bird belonged to the leucorhoa subspecies of the northern wheatear and "oen" says that the bird belonged to the oenanthe subspecies of the northern wheatear. 2. "Age.ad": This is a factor with two levels, i.e., "young" and "old". In autumn, "young" means 1st calendar year bird and "old" means that the individual was older than "young". In spring, "young" means 2nd calendar year bird and "old" means that the individual was older than "young". 3. “season”: This variable indicates whether the bird was caught in spring or autumn. 4. “change.energystores_average”: This numeric variable details the change in the energy stores as an average value over the bird’s duration of stay in a cage. This value was calculated, as detailed in eqn. 3 of the paper. In the paper, this variable is called “rate of energy accumulation”. 5. “nights_in_cage”: This variable states how many nights a bird was in a cage. 6. “year”: This variable indicates the year in which the bird was caught. 7. “Sex”: This is a factor with two levels. "1" says that the bird was a male and "2" that it was a female