If you’ve come to DeKorte lately you’ve likely seen one of our favorite spring migrants flying around the impoundments. Tree Swallows are beautiful, small, magnetic blue birds that migrate to the Meadowlands by the hundreds every spring. This afternoon NJSEA staff was out on the water installing crucial nesting boxes for our esteemed visitors.

The Tree Swallow is a secondary cavity nester, which means it must have the use of dead trees to nest in, and it must have a hole that has been excavated by a primary cavity nester.  Loss of habitat and competition for nest sites from other bird species are part of the reason why we provide these vital nest boxes for these birds.

Click read more below for a complete primer on Tree Swallows

The Tree Swallow (Tachycineta bicolor) is a small, beautiful bird about 5 ½ inches in length and has a metallic blue or blue-green upper part and a white under part. Tree Swallows are one of the first swallows to migrate back to this area for the spring nesting season. Hundreds of pairs can be found around lakeshores, streams, flooded Meadowlands and marshes.

Tree Swallows feed mainly on insects caught in flight, but they will also pick up insects from foliage. When insect numbers are low, Tree Swallows have been known to eat berries and weed seeds. The young feed exclusively on insects.  Tree Swallows feed mostly in the morning and the evening when insects are abundant. They benefit the environment by collectively devouring thousands of insects a day.

The Tree Swallow is a secondary cavity nester, which means it must have the use of dead trees to nest in, and it must have a hole that has been excavated by a primary cavity nester.  Loss of habitat and competition for nest sites from other bird species are part of the reason why we provide nest boxes for these birds. In some locations the Tree Swallows have become totally dependent on man-made boxes due to the loss of natural nesting habitat.

The birds are instantly attracted to the boxes. Some try to claim a nest box of their own before naturalists have the chance to even install it, flying into a box while it’s still on a boat.

Large flocks of Tree Swallows gather in the Meadowlands in the spring when an insect called the midge is swarming.  Midges are often mistaken for mosquitoes; they do not bite.  They will, however, swarm and hover near the water and when they are at rest they can completely cover cars, patio furniture, vegetation, windows and outside walls.