Introduction

Adult male White-breasted Nuthatch, 13 Feb 2006, Ithaca, NY.

Figure 1. Year-round distribution of the White-breasted Nuthatch.

The White-breasted Nuthatch is a small, common resident of deciduous forests in North America. Like other nuthatches, this species characteristically walks head downward on large branches and trunks, probing crevices in bark for its seed and insect prey. It also uses such crevices to hold fast large seeds and nuts, which this bird then hacks open with its bill. The name “nuthatch” is presumably derived from this behavior.

About 20 g in mass, this nuthatch generally lives in pairs in permanent territories throughout the year and regularly visits feeders during fall and winter, a time of year when pairs hoard food in large amounts, dispersing it throughout their territory and using each site to cache only one item. In some years, portions of western and northern populations do show migratory/irruptive movements, although it is not clear who these wandering individuals are or if they survive to breed near their natal areas or elsewhere.

Despite this species’ wide distribution and year-round presence in North America, its biology is not well known. This lack of information for such a common species stems, in part, because these nuthatches prefer to breed in natural holes in large, old trees, so their nests are often difficult to examine. Nevertheless, enough is known about the White-breasted Nuthatch to reveal its close resemblance to the Eurasian Nuthatch (Sitta europaea) in life history and ecology, more so than to any other North American nuthatch.

Considerably more is known about this species’ non-breeding biology than about its breeding attributes. Information on wintering birds includes nutritional condition (Grubb and Cimprich 1990, Dolby and Grubb 1998, 1999a, Doherty and Grubb 2003), foraging (Grubb 1982, Elliott 2005), caching (Petit et al. 1989, Woodrey 1990, 1991), behavior in mixed-species flocks (Berner and Grubb 1985, Dolby and Grubb 1999b), and territorial behavior and mate attraction (Elliott 2005). Key studies of breeding behavior are Kilham (1968, 1972) and Ghalambor and Martin (2000).