When to survey
Surveys for breeding birds can begin as soon as the Great Horned Owls begin courtship in January and continue until September or October when the last young fledge from the last nest of late nesting species such as the American Goldfinch. Fortunately, only a very few species nest very early or late in the year. The peak of the breeding season for most species includes May, June, and July. You should plan your field trips accordingly, so as to make the best use of your time in the field. 

Early in the year when few species are nesting, field trips can be of short duration and should be designed to search for selected species. For example, in February visit your area of coverage to look for old raptor nests which are more visible before trees leaf out. The Great Horned Owl regularly uses old Red-tailed Hawk nests. If there is no owl present you will want to revisit the nest in late March or April as Red-tailed Hawks will often reuse a nest in succeeding years. At about this time watch for territorial behavior by Horned Larks. 

As the year progresses and more species begin to defend territories, you will want to increase your visits to your area. Remember that migrants will sing during migration. Learn which species should be expected in your area to avoid the mistake of counting migrants as local breeding species. 

June and July are very good times for field trips. Confirmation through breeding criteria codes AY (adult attending young) and FL (recently fledged young unable to fly far) are more easily obtained at this time. At the same time that single-brooded species are fledging their young, species with multiple broods are renesting.  Remember that young birds begin to disperse once the parents have discontinued feeding them. This can be within two to three weeks after fledging. Caution is urged in recording FL since young birds flying well could have been raised outside the atlas block you are covering. 

The best time of the day to plan your visits is the early morning--usually the period from 5:30 to 9:30 A.M. in the summer. The greatest bird activity occurs at this time. Bird activity again picks up in the late afternoon and early evening. Crepuscular (active at twilight or just before dawn) and nocturnal (active at night) species may require visits in the early evening, after dark, or at dawn. Common Snipe, American Woodcock, Common Nighthawk, Whip-poor-will, and owls are species which can be more easily recorded at such times.

The New York state breeding bird atlas project has produced a table of nesting dates you might find informative.  The Michigan list is in the Atlas Handbook.