Melozone aberti

Mitochondrial genetic data (DaCosta et al. 2009) have shown that the genus Pipilo comprised two unrelated groups, one consisting of ocai, chlorurus, maculatus, and erythrophthalmus, the other of the "brown towhee" group: fuscus, albicollis, crissalis, and aberti. The same study revealed that Melozone kieneri forms a monophyletic group with the brown towhees, and that M. leucotis and M. biarcuata are closely related to this group. Although DaCosta et al. (2009) suggested that kieneri, fuscus, albicollis, crissalis, and aberti be transferred to the genus Pyrgisoma, thereby splitting Melozone kieneri from its congeners, we have taken a more conservative approach, consistent with phenotypic similarities between M. kieneri and M. biarcuata (e.g, they were treated as conspecific by Hellmayr [1938]), and merged the brown towhees into Melozone (AOU 2010).

This species occupies a relatively small geographic range in southwestern North America. Most populations experienced historical declines from extensive loss, modification, and fragmentation of native riparian habitat. Habitat loss in some parts of its range continues as do losses to urban and agricultural land uses. Trends are currently likely stable as the Abert’s towhee makes extensive use of exotic and human-created or modified habitats.

The range of the Abert’s towhee in the U.S. coincides with the southwestern Sonoran Deserts and includes most of Arizona, southwest New Mexico, southeastern California, and the southern tip of Nevada. It occurs sparsely in the far northern end of Baja California and Sonora, Mexico. Based on analysis of locations from research-grade iNaturalist breeding season records (April through August; all years) retrieved from the Global Biological Information Facility (GBIF 2022), the range extent of the Abert’s towhee is about 318,595 km2.

The number of occurrences of Abert’s towhee is unknown. Considering nest densities described by Tweit and Finch (2021) in the context of an occurrence for this species and the extent of riparian woodlands within the Abert’s towhee range, there are likely greater than 300 occurrences of this species.

Loss of riparian habitat throughout this species range is likely the single most pervasive threat to Abert’s towhee populations. Restoration has offset some of this loss but has likely been insufficient to reduce this threat below a population-level impact. Urban and recreational development in parts of this species' range have significantly reduced habitat while in other parts has created an urban breeding environment. Displacement of native shrublands with agricultural uses, including grazing, remains a threat in many parts of this species range. Tweit and Finch (2020) suggest nest predation rates may be higher than expected from native predators due to evidence of predation by house mice (Mus musculus). However, nest densities in urban and ornamental vegetation settings appear to be the same as those in riparian thickets (Tweit and Finch 2020) suggesting background predation rates by introduced species in urban settings may not be a serious threat.