Posted: 19/04/2014 at 15:01
I think the problem is that there are now fewer nesting sites for swifts in that we have relatively few old and crumbling/badly maintained properties here in the UK than in other parts of Europe. Swifts and housemartins don't have the same type of nests - in that the latter make nests in much the same way as swallows do, whereas swifts nest in nooks & crannies in roof spaces rather than making a nest of their own with mud etc. on the outside of a wall. In warmer countries, such as those round the Mediterranean, not only are there proportionately more older properties than we have in the UK, but it seems to me that people there don't have the same need to make sure their homes are well-insulated & maintained in order to reduce fuel bills.
Saw swallows round here this past week - one pair has "returned home" to one property locally, whereas the others must have been in transit to somewhere further North. I usually make a note of the first time/place I see them each year - last year the first sighting (by me) was 21st. April.
One thing that's always puzzled me - ref swallows etc - is where did they nest before we built houses etc? I see sand martins' nest-holes in sandy/pebbly riverbanks and assume that rocky outcrops would have been suitable for swallows - but did swallows etc begin to flourish when they had more available nest sites with the advent of mankind's creation of permanent settlements? Where did they perch before there were telephone lines & roofs? I've never seen one fly out of a tree! Anybody know the answer?
p.s. just been out in the garden for a bit - saw two swallows on the telephone wire - definitely a pair 'cos they were "at it" (!) already. Also disturbed a sitting wren - which I didn't know had its nest in the ivy on the wall near the back door. I was trimming away some of the new growth on the wall and she almost flew in my face - her wings brushed my forehead! I didn't look too closely to count just how many eggs, but hope she goes back soon. The nest is only about 5ft from the ground.