During the fourth week, from May 1–7, weather conditions continued the gradual transition into a milder spring pattern, though the week included a mix of changing conditions typical for early May. Temperatures generally ranged from the upper 50s into the upper 60s, with a few cooler mornings and occasional breezy periods. The week featured intervals of sunshine mixed with cloud cover, along with scattered showers and damp conditions at times. Overall, the weather remained relatively moderate and stable, providing favorable conditions as the peregrines moved through the final stages of incubation and approached the expected hatching window for their four-egg clutch.

By the fourth week of incubation, the developing peregrine chicks are entering the final and most active stage before hatching. Inside the eggs, the chicks are now fully formed, covered with a fine layer of down, and occupying much of the available space within the shell. Their bones, muscles, eyes, beaks, and talons are well developed, and movement inside the eggs becomes more noticeable. As hatching approaches, the chicks begin positioning themselves for emergence, orienting toward the internal air cell that will support their first breaths. This is also the period when faint peeping sounds or subtle rocking of the eggs may occasionally occur shortly before pipping begins.

The adult peregrines become especially attentive during this final stretch. The female continues to perform the majority of incubation duties, remaining low and steady over the clutch for long periods, particularly during cool nights or wet weather common north of Boston in early May. The male remains highly involved, regularly delivering food and taking short turns on the eggs while the female feeds, stretches, and preens nearby. Exchanges between the pair are quick and coordinated, minimizing exposure of the eggs during these critical final days. With hatching now imminent, the pair’s focus shifts from simply maintaining warmth to preparing for the demanding transition from incubation to feeding and brooding newly hatched chicks!