April 16, 2026: Over the past week, early spring has continued to make its presence felt with a mix of mild, seasonable temperatures and variable conditions. Daytime highs from the mid-40s to low 60s, with cooler mornings and occasional breezy periods. There have been a few stretches of cloud cover along with intermittent rain, typical of April’s transitional pattern, but also some brighter, calmer windows. Overall, the weather has been well within the normal range for this time of year, providing stable conditions as the peregrines settle into full-time incubation.

In the first week of incubation, the four eggs are in the earliest stages of development, with cell division underway and the embryo beginning to form along the yolk surface. From the outside, little appears to change, the eggs remain still and subtly colored, but inside, the foundations of the chicks are being established. Maintaining a steady temperature (around 99–100°F) is critical at this stage, especially in early spring conditions north of Boston, where cool air and shifting winds can quickly affect exposed eggs. The female settles low over the clutch, using her brood patch to transfer heat, while making small, regular adjustments to keep all eggs evenly warmed.

Incubation duties are shared, though the female does the majority of the work. She typically remains on the eggs for long, consistent stretches, especially overnight, while the male provides food and periodically takes short incubation shifts during the day. These exchanges are smooth and efficient, the arriving bird may vocalize softly before the sitting bird rises, carefully revealing the eggs before switching places. The male’s time on the eggs is usually brief, but important, allowing the female to stretch, feed, and maintain her own condition. This steady rhythm of care continues through the coming weeks, setting the stage for successful hatching about a month from now!