If you have been hearing them in the same place for a week or more they would be considered probable nesters according to Vermont atlas criteria.
Sent from my iPhone
> On Jun 5, 2018, at 10:02 AM, Walter Medwid <[log in to unmask]> wrote:
> I have Parulas and Blackburnians, among other warblers, calling at my
> location in Derby. Is it likely that they are nesting residents at this
> time of year (vs moving on elsewhere to nest)?