Figure 1. Female on nest at or near commencement of incubation. May 23, 2024.

A fun and rare opportunity presented itself to my wife and me during the spring of 2024. Due to a fortuitous site choice on their part, we were privy to the intimate details of nesting behavior by a pair of Rose-breasted Grosbeaks at our property in Unity, Maine. Our yard includes about an acre of open space that is landscaped with various fruiting trees, a wildflower patch, snags, brush piles, and a large garden. The mixed forest and edge habitat around it produces multiple broods of this confiding species each year. This note recounts the regular observations made from before nest construction to postfledging.

The grosbeaks arrived on May 7, a later date than in most years. According to Wyatt and Francis (2020), first arrival in the northeastern United States and southern Canada ranges from mid-April to early May. We noted at least six grosbeaks on May 10 and as many as a dozen were present on May 12 when we also observed a pair copulate. Francis and Cooke (1990) reported that males arrived earlier than females in Ontario but the difference in mean arrival was only one day. Not surprisingly, most years we see a male in the yard slightly before we detect females.