Jean-Luc Des Granges, "Organization of a Tropical Nectar Feeding Bird Guild in a Variable Environment," The Living Bird Seventeenth Annual of the Cornell Laboratory of Ornithology, 1978


Relative seasonal availability (RSA) of nectar in tubular and cup-shaped flowers during the five time periods in each of the four habitats. RSA in the amount of nectar (A) in flower (j) in habitat (h) during time period (t) expressed as a proportion of the maximum amount of nectar found in either of the two flower types in that habitat during any period of the year, (i.e. RSAjht = Ajht/maximum [Ajht]; t 1,5; = 1,2). Arms of the stars represent periods of the yearly cycle with the arrival of migrants at the top and, in clockwise progression, mid-winter, departure of migrants, the end of the dry season, and the beginning of the rainy season.