In south Texas, as well as in B.C., migration is underway!
In B.C. at this time of year we witness the departure of some of the winter birds, and at the same time, the arrival of migrants and summer birds.
The situation is much the same down here. One of the first signs of spring here is the arrival of the Purple Martins. I usually see them before the end of January.
Upon arrival, their first task seems to be to evict the House Sparrows that are already trying to nest in the martin boxes. The martins seem to have well developed eviction skills! In early February, the Northern Mockingbirds begin to sing.
I assume that singing is something they like to do since they often keep it up all night.
There are other signs of the changing seasons as February progresses. The Tropical Kingbirds and the Loggerhead Shrikes form pair bonds; I saw the shrikes building a nest in the first week of March.
A flock of Yellow-rumped Warblers passed through our RV park at the end of February. And at the same time, others are leaving.
Two very common winter birds here are Orange-crowned Warbler and Ruby-crowned Kinglet.
Any winter visit to a woodland would produce a dozen or more warblers and a few kinglets. But by mid-March they were virtually all gone; in the last weeks I have seen two warblers and no kinglets.
Many other species arrive in March, some to stay, some just passing through.
Some aspects of the migration are quite spectacular. Broad-winged Hawks are one of the most common raptors in North America. They winter in Central and South America. When migration is in full swing, hundreds, sometimes thousands, can be seen passing by in a single day!
Mississippi Kites also migrate in flocks. There is a Hawk Watch station in Bentsen-Rio Grande State Park; they are now reporting the first groups of Broad-wings, (Mississippi Kites pass through a little later).
We will be at Bentsen in a few days and hope to witness some of this migration spectacle.
In B.C., migrating birds are observed quite early in the spring, but the bulk of the movement happens a little later, in May.
Similarly in south Texas, migration starts slowly and peaks a little later, in April.
The geography of Texas plays an important role in the migration story. Many birds have to fly across the Gulf of Mexico.
This is no small feat for warblers, vireos and hummingbirds! They typically gather on the southern shores waiting for favourable winds to help with the crossing.
If conditions are poor, large numbers may pile up waiting for a change. When the change occurs, hundreds of thousands of small woodland birds head north across the wide expanse of water.
If conditions remain favourable throughout the trip, the distance poses no great hardship.
But occasionally the winds change mid-flight and the journey becomes a battle of endurance.
After a difficult crossing, birds arrive on the south coast of Texas in an exhausted condition. They flop down as soon as they reach land.
I have seen warblers standing in the middle of a road, and hummingbirds lined up along a wire fence beside the Gulf. It certainly makes the birds easy to observe because almost nothing will cause them to move once they have landed and are resting. Any woodlands that occur on the Texas coast are highly favoured by birds, and bird watchers alike! One of the most famous is High Island. This is not an island in the strict sense, but is an “island of trees”, in an otherwise flat open plain. At the peak of migration, mid-April, birds arrive in the millions; and birders in the thousands.
Officially, tomorrow is the first day of spring, (a bit later by the time you read this), but there’s already lots of changes happening the natural world. Next time you’re out, have a look and see what’s going on around you!
