The subspecies of northeastern Brazil is Leptotila v. approximans (Pinto 1949). RPPN Mãe-da-lua.
Figure 1. Two species of Leptotila doves occur in Ceará, namely the White-tipped Dove L. verreauxi and the Gray-fronted Dove L. rufaxilla. These species look so similar to each other, that even experienced observers have difficulties to tell them apart in the field. See for example Belton 2003, and Pinto 1949, p. 301. But they can be distinguished based on their vocalizations, see here for details.
There are probably morphological differences as well (periorbital skin?), but I found the literature unconclusive, and I have not yet seen L. rufaxilla in Ceará myself. This text will be updated when more reliable information becomes available.To top of page
Figure 3. White-tipped Dove taking off. The rufous color of the underside of the wings is now visible.To top of page