Spring "vismig" at Lighthouse Point

Last year (2025) I began to toy around with observing spring diurnal migration at Lighthouse Point in New Haven, CT. Well-known as one of the premier coastal autumn hawkwatches in New England, Lighthouse gets little attention in spring. This is understandable, as Connecticut's east-west coastline (land to north, water to south) is really set up for southbound migration, as Long Island Sound acts as a barrier to birds that prefer to migrate over land. 

Last spring I made a few visits on northwest winds, just to see if any overland birds might be pushed to the coast. I did observe some migration, which was pretty cool, but what really surprised me was the direction of the movement. Just about the entire flight of raptors, swallows and swifts was westbound down the coast. This is the direction that our autumn (southbound) migrants usually take.

a spring migrant American Kestrel at Lighthouse Point

typical direction of southbound diurnal migrants through Connecticut during autumn

To be honest, I was expecting eastbound heading, as the direction of the local flyway in spring is generally north/northeast. Theoretically birds that prefer to migrate over land would head up the mid-Atlantic coast and then angle eastward as they fan out over New England.

the anticipated direction of northbound diurnal migrants through Connecticut during spring

But these spring birds were taking the normal southbound autumn route (insert shrug emoji here).

My interest was piqued, and I followed up this spring. I made three spring visits in 2026: Apr 11, May 1, and May 3. Each of these vigils lasted about 1-2 hours and had NW wind of varying intensity. All of those days were seasonably cool, if not downright cold. On each day I had just a few birds moving. A few raptors, swallows, and blackbirds were seen moving westward...but it was a slow trickle at best. None of these flights were as good as the flight referenced above from April 2025. That day was relatively warm compared to this year's attempts, which might have had something to do with it? Unsure.

The prize from this year's effort was a SWALLOW-TAILED KITE moving west down the coast on May 1st. The direction of this bird actually makes sense, as an overshot kite might be expected to reorient back south by using this coastal flight line.

That's the story so far. The jury is still out on 1) whether this is a worthwhile way to spend my birding time in spring, and 2) what exactly explains the apparent westward movement observed.

We'll see what 2027 brings as the experiment continues.

 - NB