A curious clump of leaves hanging in your New York tree can stir your curiosity. It may not be a nest at all—it’s often something far more intriguing.
Nature loves to disguise its wonders in plain sight. Let’s reveal what that shape truly is this season.
1. Squirrel Dreys
Those big, messy balls of leaves and twigs aren’t always bird nests. Gray squirrels across New York build these cozy homes called dreys, usually tucked between branches. They weave together leaves, bark, and moss to create waterproof shelters.
Inside, squirrels line their dreys with softer materials like grass or shredded bark. A single squirrel might build several dreys throughout the season for backup options!
2. Witches’ Broom
Sometimes what looks like a nest is actually a weird plant growth. Fungal infections, mites, or viruses can cause branches to grow in tight, tangled clusters. This creates a dense, nest-like shape that fools many people in New York.
The condition doesn’t usually kill the tree, but it does look strange. You’ll notice the branches are much thicker and more compact than normal growth patterns.
3. Mistletoe Clumps
Parasitic plants can trick your eyes too. Mistletoe attaches itself to tree branches and grows into round, bushy clumps that resemble nests. Birds spread the seeds when they eat the berries, helping mistletoe spread throughout New York trees.
The plant steals water and nutrients from its host tree. Over time, heavy mistletoe growth can weaken branches and cause them to break off.
4. Galls from Insects
Tiny insects can create surprisingly large structures. When wasps or other bugs lay eggs in tree tissue, the tree responds by forming galls—abnormal growths that protect the larvae. Multiple galls clustered together can look exactly like a nest from below.
These growths are common in New York’s oak and willow trees. The insects eventually emerge, leaving behind hollow, woody balls that persist for years.
5. Old Leaf Clusters
Wind and weather play tricks on us all the time. Dead leaves get caught in branch forks and accumulate into messy clumps that look surprisingly nest-like. During fall and winter in New York, these leaf piles become especially noticeable against bare branches.
Unlike real nests, these clusters fall apart easily during storms. You might see them disappear after heavy rain or wind, only to reform elsewhere.
6. Bagworm Cases
Caterpillars are master builders in disguise. Bagworm larvae spin silk cases and cover them with bits of leaves and twigs from their host tree. When dozens hang together on New York evergreens, they create a clumped appearance that mimics a nest.
Each case houses a single caterpillar that feeds on the tree. Heavy infestations can seriously damage or even kill young trees over time.
7. Crow or Hawk Nests
Okay, sometimes it really is a nest—just not the kind you expected. Large birds like crows and hawks build massive stick platforms that look nothing like the tiny, tidy nests smaller birds create. New York’s urban areas host plenty of these impressive structures.
These nests can measure two feet across and get reused year after year. The birds add new material each season, making them grow even larger over time.