Every year at this time many species of birds that flew south for the winter begin to return. The very earliest to return are those that weren’t really very far away to begin with. American Robins, Red-winged Blackbirds, Canada Geese and several species of ducks for example, regularly winter either on the coast, or just a little south of here.
The first really long-distant migrant to return is usually the Violet-green Swallow. A few winter in the southern States, but most go to Mexico or Central America. When the first swallow arrives, we know that spring migration is underway. My personal records show that the average date for the first swallow in Nakusp is around March 20. This year it was March 24. Like all swallows, Violet-greens are aerial insect eaters. In years when March weather is a little cooler, insects are less active and swallows are more likely to delay their migration somewhat. Similarly, in warm years they may advance a little earlier. In 2005, I saw a swallow on March 5, but in 2001, I didn’t see one until April 4. In almost every other year, arrival falls between March 18 and 25.
Violet-green Swallows are one of six species of swallows that occur regularly in B.C. Since several of them are quite willing to live and nest in human-altered habitats, they are quite familiar to many people. Violet-greens and Tree Swallows are the two species that nest in nest boxes. There are many boxes throughout towns and on fence posts in farmland. If you see a swallow entering a box, you can separate the two species by looking at the colour that reflects off their backs in bright sunlight; Violet-greens are green, Trees are blue.
Two other species that have similar nesting habits are the Rough-winged Swallow and the Bank Swallow. Both are brown on their backs and very similar in appearance, and both nest in burrows in sandy banks. A quick way to separate the two if you see them entering such burrows is to see how many there are. Rough-wings usually nest as single pairs, or maybe with one or two other pairs close by, but Bank Swallows nest in big colonies. There could be anywhere from a dozen to several hundred pairs nesting in the same bank.
Such dirt banks are not common in our region; as a result Bank Swallows are not often seen here. I am told there is a large dirt bank along Arrow Lake that has a Bank Swallow colony, but the site is only accessible by boat and I haven’t seen it. On occasion, Rough-wings will nest in crevices in rocky banks. There are a few nesting in the rocky road cuts in our area.
The last pair is the Barn Swallow and the Cliff Swallow. Again these two have similar nesting habits; both build nests out of mud. They usually attach them to buildings, or put them under bridges or on rocky cliffs. Like Bank Swallows, Cliff Swallows are colonial nesters. Some larger building or bridges may have hundreds of mud nests, all occupied at the same time. Barn Swallows do not like neighbours; they nest in single pairs.
Even though all swallow species have very similar feeding habits, they do not all return to the area at the same time. Violet-greens are the earliest, followed closely by Tree Swallows, (average arrival date March 29). Rough-wings don’t arrive until about April 22, and Barn Swallows not until May 1.
There is some concern about all species of swallows in North America. Their numbers appear to be declining. I plan to document, as closely as I can, all nesting swallows in the area this year. As the season progresses, if you see swallows nesting on your property, and if you’d be willing to keep an eye on them periodically, please let me know.
