Morning Swift,
I've no expert advice to give (as I'm not an expert), but here's what I know having talked to a few who are in the know.
We have a similar situation to yours and have placed boxes under the eaves. We've the advantage of having helpfully placed windows and ledges.
We bought our boxes directly from BirdLife Switzerland (that's where we live). A local engineer and swift enthusiast also makes boxes. The two designs are almost identical I understand.
Re attracting Swifts, our boxes have been up for two breeding seasons and not a sniff. As an acquaintance at BirdLife Switzerland explained, Swifts are conservative birds, and for them to use boxes, they need to alter their mental picture of what and what does not constitute a nesting site. So, it's not just the right-sized hole (which is, I think, fairly standard on most designs, although I can't remember what it is... 78mm by something or other...).
We were recently told to "dress" the boxes. So, place a few leaves and some dry grass around and a few stems of grass sticking out. This tells the birds that this is a nest (or that House Sparrows have already used it, so it must be a nest). I've done that, but probably far too late in the season. We'll see if that has some effect next year.
You can also buy CDs (or, I guess, downloads) of swift calls. That and a little battery-operated Bluetooth speaker might be worth a try, particularly if you have no under-tile nesters to do that job for you.
We've been advised to keep the boxes closed until just before the swifts arrive. This stops sparrows squatting in them. And, of course, ensure that nothing can improvise a nest on top of your boxes. Our boxes (wooden) can be quickly modified to be mounted widthways or lengthways. Either way, there's a sliding metal door that covers the entry hole. I open that when I see the first birds arriving.
Here, we have three distinct waves: passage birds, those that have already nested in a previous year, those that have yet to nest (so, the bouncers that skim off the eaves looking for potential nesting sites for this, or next, year). Once the passage birds are sighted, the birds that are yet to nest are probably close behind (a matter of days), so it's relatively easy to judge when you should open your boxes up.
Elevation and flight path are both also important, and for the last two years we've been working on giving our under-tile nesters a good, unobstructed way in to their nests (and so, on giving the youngsters when they eventually fledge a good, unobstructed way out into the world).
We've also pruned east--west, so we've a clearer path across the south side of the house.
This attention to flight paths has taken us up from one success and one failure in 2020 to one failed nest this year with three on the go; all under the tiles.
I hope that at least some of the above is a help to you.
Best regards -
Dave
That is a great link from Internetman. And Robbo is absolutely right about elevation being important.
@Swift: If you have the option of having the boxes easily accessible, you'll be the darling of anyone working in swift conservation.
Swifts (Common Swifts at least ) will fairly readily accept and adopt orphans, which means that easily accessible boxes are a boon.
As an acquaintance of ours says, he'd rather walk up the stairs to our attic than be 6m up on a ladder. And he himself has a large colony; last count is boxes in 3 figures I believe.
In reply to jgtuk:
jgtuk said:This year the Swifts arrived a little later
General (expert) consensus here in Switzerland is 3 weeks later than "average" jgtuk.
In reply to Dave - CH:
jgtuk said:a lot of people saying overall numbers down this year
I've a note to ask Sempach about that in Nov/Dec jgtuk, when they have a better handle on the figures. There seems to have been no or only little delay further into the Jura, down at lower altitudes, and an acquaintance up toward the Clos du Doubs hasn't commented on reduced numbers (yet).
Friends who work in rehab. centres are saying that numbers are down for swifts (Common and Alpine) and House Martins. But I don't think we can say yet whether it's the birds that have changed or the people (who find birds and take them in to rehab.) I was meant to do the House Martin count again this year (sensibilization thing with schools), but the weather put a stop to it.
We're not so far from Neuchâtel (a little further north, in the hills). In fact, I was there this afternoon, but for the first time in... well, a long time.
Doesn't seem to have changed much: looks great, but you couldn't get a coffee there today if you'd had a bag of gold. Still, the young GK Grebes are looking very nice bobbing around the harbour.
All the best -
In reply to Swift1235467:
Hi Swift. I have deep soffits so made the shoebox type as found on https://www.bristolswifts.co.uk/swift-nest-box-design/
This is one of mine (speaker removed from holder after Swifts were established), I had to paint in Farrow and Ball colours before my wife allowed installation