The Comparative Ethology of Grassfinches (Erythrurae) and Mannikins (Amadinae)

SUMMARY The behaviour of twenty‐seven species of estrildine finches is concisely reported. Brief information is also given about the geographical distribution and the comparative morphology of the Estrildinae. Ethological, geographical and morphological data are then combined in a discussion of the evolution of the group, and finally some minor taxonomic revisions are suggested. Most of the ethological research has been concentrated on similarities and differences in sexual patterns, and the pre‐copulatory behaviour of the following species is described: Zonaeginthus pictus (Painted Finch); Z. bellus (Fire‐tail Finch); Z. guttutus (Diamond Sparrow); Poephila phueton (Crimson Finch); P. rujcuuda (Star Finch); P. guttutu (Zebra Finch); P. bichenovi (Bicheno Finch); P. modesta (Cherry Finch); P. cincta (Parson Finch); P. acuticuuda (Long‐tailed Grassfinch); P. personata (Masked Grassfinch); P. gouldiae (Gouldian Finch); Erythrura spp. (Parrot Finches); Padda oryzivora (Java Sparrow); Amadina fasciatu (Cutthroat Finch); A. erythrocephala (Red‐headed Finch); Lonchura pectoralis (Pectoral Finch); L. malabarica (Silverbill); L. bicolor (Black‐breasted Mannikin); L. cucullata (Bronze Mannikin); L. striata (Striated Finch); L. punctulata (Spice Finch); L. ferruginosa (Chestnut Mannikin); L. maja (Pale‐headed Mannikin); L. castaneothorax (Chestnut‐breasted Mannikin); Estrilda temporalis (Red‐browed Finch). Many of the sexual displays have been derived from nesting patterns, as a result of the intimate association in time of high intensity reproductive nest‐building and high intensity courting. Straw‐holding, bowing‐with‐straw, looping straw, mandibulating, tongueing, and cavity‐scooping have been incorporated in the courtship sequences of many species and there are interesting specific differences in the ways in which these patterns have become modified as signals (i.e. ritualised). Displacement beak‐wiping is also an important source of ritualised signals' in various species; here too there are specific differences in the extent and nature of the ritualisation. The vertical inverted curtsey dance and the horizontal pivoting dance of the males are derived from intention movements of approaching and avoiding the female. Certain pair‐formation ceremonies are shown to be related to sunbathing patterns. The evolution of the group appears to have taken one of the following two possible courses: The group seems to have originated in Africa and from there to have spread around the Old World to Australia via Asia. This probably involved ancestoral mannikin forms, which gave rise to the grassfinches when they reached Australia. Many of the grassfinches are now extremely convergent with certain African waxbills. The alternative evolutionary scheme, which cannot be ruled out on the present evidence, is that both ancestoral mannikins and waxbills spread round to Australia and that the grassfinch group is not a natural unit, but that part of it has come from ancestoral mannikin stock and part from ancestoral waxbill stock. The former view is favoured here, but it is stressed that more information is required to be certain on this point. In conclusion, a taxonomic revision is presented, as far as the species discussed here are concerned. This involves the following changes to Delacour's (1943) arrangement: the setting up of three more subgenera (Spermestes; Gouldaeornis; Aegintha) and two more genera (Aidemosyne; Bathilda); the shifting of the Red‐browed Finch from the waxbill tribe to the grassfinch tribe, and several other minor alterations. No new names are introduced; in each case an old name discarded by Delacour has been revived. Delacour's revision of the group was extremely valuable in sweeping away a mass of unnecessary “splitting”, but it over‐compensated, and it is now necessary to reverse a few of his more extreme “lumpings”.