The Swifts are coming! ...hopefully

 Our BirdNet-Pi system has gone crazy!

 

Its suddenly reporting hundreds of Swift calls.

So what going on?

Swifts are on the red list. This long distance migrant is in decline and I feel they need our help.

On a recent trip to Croatia, we were amazed by the number of swifts flying, screeching & nesting above us in the streets of many towns & cities such as Dubrovnik. Before we went on this trip we had already put our name down for a swift box with a local guy, Paul Stevens.

So when we returned from our holiday, we were even more keen to get moving and get a box fitted. Our BirdNet system detected around 15 swift calls during June, similar to the count for 2024, so we knew these birds were around our area.

Paul manufactures, supplies & installs a variety of boxes for various bird species.

 

Our new swift box fitted to the north apex wall

In order to increase the chance of a new box being used by swifts, callers are fitted which basically play swift calls to attract the birds down. Swifts prefer sites already colonised by other swifts.

inside the swift box

Swifts like to use the same nest each year, so its not generally possible to get established birds to move home. But if they return from Africa in the summer and find that their old nest has been removed due to housing development, they have to start again.

The general sequence is that swifts return from Africa in May, locate their old nest, raise chicks, then fly back to Africa late July or early August.

However, immature birds still make the round trip, but checkout suitable locations for the following year, when they may be ready to mate.

So by playing swift calls early in the season (from May onwards) you may attract mature birds looking for a replacement nest site.

Then by playing calls latter in the season (June/July/August) you may attract immature birds looking for a place to come back to.

I installed our caller controller in the loft, along with a mains timer.

Initially we will run the caller all day, from about 5am to 9pm. However, this has a down-side...

...its messing up the stats on our BirdNet system!

We also have no way of separating the caller calls from the real swift calls. So I may have to switch to some kind of recognisable pattern after a week or two (...maybe 1 hour on then 1 hour off).

a few Swift facts

Estimates vary, but it is thought that a swift may fly 4,000,000 miles in its lifetime.

They fly almost continuously, only touching-down to enter their nest box.

They even sleep on the wing, but not as we would recognise sleep; they shut down half their brain for a few seconds at a time, then the other half.

They are the fastest level-flight bird.

Chicks can go into a kind of hibernation mode known as torpor if food is scarce. They also do press-ups in the nest to strengthen their wings because once they are out of the nest, they are out for good ...no trial runs.

How big:-

 - length: 16-17cm

 - wingspan: 42-48cm

 - weight: 36-50g

 - max speed: nigh on 70mph