A sure sign of the arrival of Spring in Paraguay is the reappearance of the swallows.

These small birds vanish from the skies as winter arrives. Migrating north to where the chills of winter never reach.

The common swallows seen throughout Paraguay are Blue and White Swallows. They are coloured as their name suggests. Dark uppers, wings and tails and a white underside.

The Blue and White Swallows are found throughout South America. On into Central America and as far north as Nicaragua.

In much of their range they remain in a home territory throughout the year. However birds found further to the south in places such as Paraguay do migrate. Some of these migratory birds travel as far north as Trinidad. There is no way of telling quite how far my particular birds travel.

The Blue and White Swallow is a bird of open spaces. Its primary food is insects caught on the wing and as such is best suited to open landscapes. Across South America it can be found everywhere except deserts and the thickness of the Amazon,

As humans clear land for their crops and their houses they create ideal living spaces for the swallows. They are a common sight above fields and in town centers.

They are at home in habituated areas. Often buildings are used as ready made nest sights.

I have a pair of swallows that have been returning to may house for many years. Each year without fail they return to refurbish and reuse the same nest site.

There nest is built at the back of the house under the roof tiles. There is just a very small entrance to the nest and an accurate landing is required to reach it.

The birds arrive at speed taking a dipping trajectory across the garden and towards the house. Then at the last moment the head upwards to the nest from below.

This usually ends in success. However occasionally the flight path is misjudged or there is a sudden strong gust of wind. Then the landing is aborted and the swallow flies high over the roof before making another circuit and trying again.

Each morning when I open the back door the swallows have already left the nest and are perched in trees behind the house. They will continue to be there every morning as long are they are occupying their nest.

Once insects are on the wing the swallows will spend much of their day in the air in pursuit of them. The birds are fast flying and will often take a circular path through the sky. There may be a swam of insects there as few of which will be picked off on each pass.

Inside the nest young are raised on insects bought back by their parents. Later in the year once the chicks have fledged two will become four. Then after a month or two they will be once more on their travels.

The next year the parents will return once more to their nest and the youngsters will head off to form families of their own elsewhere.