Autumn

Hudson Valley through the Highlands - Mt Taurus This is the month of spectacular changes in the color of the foliage up and down the valley.

Monday, September 22 marked the official beginning of Fall. On the day of the equinox, the hours of daylight and darkness are just about equal. On the first day of summer back in June, the hours of daylight were the longest of the year. The days gradually became shorter as the sun appeared to move further and further south each day. We actually “lost” 77 minutes of daylight in September! From this point on for the next three months, days will continue to become shorter on an average of 2.5 mins per day. The rate will slows down as we get closer to the shortest day of the year, the winter solstice on December 21st. This change on duration of sunlight is surmised to be one of the triggers that gets birds migrating south in the fall.

Mallard pair - Iona Island 9/26

Each fall, mallards embark on their migration through New York, taking advantage of the state's diverse wetlands and waterways like Iona Island as crucial stopover sites. As temperatures begin to drop, these adaptable ducks gather in large flocks, feeding heavily on available aquatic plants and invertebrates to build energy reserves. New York's lakes, rivers, and marshes provide essential resting points during their journey southward to milder climates. The migration period typically spans from late September through November, with peak movement varying based on weather conditions. Observing mallard fall migration in New York highlights the species' resilience and the importance of conserving wetland habitats along their migratory paths. Earlier this month, we found only a few pair, some in eclipse molt. This week, however, larger flocks of 20 or more mallards showed up at Iona as they begin their journey south.

Tufted titmouse Iona Island 9/26

Not all of our New York birds find it necessary to migrate, however. Another bird I photographed on Iona today was this handsome Tufted titmouse. The tufted titmouse is one of the species which do not migrate from New York primarily because it is well adapted to the region’s climate and food availability throughout the year. This small songbird has a flexible diet that includes seeds, nuts, insects, and berries, allowing it to find sufficient nourishment even during the colder months. Additionally, tufted titmice have evolved behaviors such as caching food to survive winter when resources are scarcer. Their ability to endure cold temperatures without needing to relocate reduces the need for long-distance migration, enabling them to remain in their established territories year-round.

Sugar maple leaf just beginning to change - Bear Mt. 9/16/25

One of the most anticipated natural events in New York at this time of year is the changing of the color of the leaves on our trees. Leaves change colors in the fall due to changes in daylight and temperature, which cause chlorophyll, the green pigment in leaves, to break down. As chlorophyll diminishes, other pigments present in the leaf become visible. Carotenoids produce yellow and orange hues, while anthocyanins create red and purple tones. This process allows trees to conserve energy and nutrients in preparation for winter while producing the vibrant display of autumn foliage. We are just entering that time of year here in the Hudson Valley. When the leaves become their most vibrant is dependent upon their geographical location to a great extent as well as the species of tree. Maples are one of the first to change and we found a few up on the mountain that are just beginning to change. Later this month and even into November, we’ll see the Oak, Beech, and Hickories change.The leaves on my Black Walnut here in the back yard have already begun to turn and fall. Here in the valley, we expect “peak color’ sometime later in October. If you are too anxious to wait, you can always travel north to catch the earlier change of colors. Check out the map below for an idea of where and when you find Peak Color.

Peak colors on September 28, 2025

And so, while we continue to look for migrating hawks and eagles which lately are few and far between, we will also look for other signs of the season. I hope to have some spectacular colors showing up in a couple of weeks to share with you.