.I have been curious as to the exact state of affairs of our local urban/suburban martins, as in just how many housing sites? what sort of housing? how is it maintained? how many pairs?
I was able to get out and about today armed with a GPS unit to record located sites. The method: methodically cruise up and down residential streets in my general neighborhood, looking either for housing or for martin activity indicating nesting/young.
Driving miles covered: 24miles Time spent: 3 hours 45 minutes.
Ballpark number of separate houses/yards viewed: ~2,100 (surprised me too, but repeated measurements turned up 10 to 14 lots per 0.1 mile of street, counting both sides of the street, I substracted vacant lots lots and fields). All houses on small residential lots. All about 40 years old.
Martin housing sites located: 26, the furthest being 3.26 miles from my house.
Six sites were located by martins diving down into backyards, the housing could not be seen from the street.
Which brings up a common feature of local martin housing: it is most often located lower to the ground and closer to trees than is commonly considered acceptable
All 20 sites seen consisted primarily of multi-compartment houses, two sites also contained gourds. One with eight old Carrols, one with eight SREH Big Bos.
Four sites had SREH crescent openings: those eight Big Bos, two S&K houses, and a Lone Star? house. The rest were round hole.
Eight sites employed trio castles, varying numbers of tiers.
Five sites consisted of two or three houses.
Four sites appeared to be reasonably well maintained. The other sixteen of those seen contained sparrows, usually occupying 50% or more of the cavities. Only one starling seen, but most may have fledged young by now. Three sites had no apparent martin activity.
Haven't crunched the numbers for average # compartments per site yet, at this point I'll ballpark ~15.
The number of martin pairs in residence was difficult to gauge without stopping and staring. I would guesstimate one to three pairs for most occupied sites. More of course for the reasonably well-maintained sites,
Three pairs in adjacent old Carrol gourds overlooking a busy street contained `26+ day-old young visibly about to fledge.
I got to talk to two martineers, both with reasonably well-maintained sites, one with a two-story trio castle one with two twelve-hole houses, they weren't sure how many martins they had but both controlled sparrows.
I doubt if more than one or two of of these 26 actual or potential landlords conducted nest checks, most housing being put up on simple poles.
An afternoon well spent. Only two weeks of school left, but I shall turn the students loose with borrowed GPS units in their own neighborhoods.
I would still like to locate 100 housing units, and then see what happens in them as time goes by.
I will say that only six of the twenty sites I saw contained reasonably new housing, for the most part the housing was faded and old.
The results ballpark to one martin housing site per 80 human houses. This in older neighborhoods with actual yards, rights of way between rows of houses also adding space, and less restrictive homeowner's agreements.
I did cruise through one recent housing development: closely spaced two story houses on postage stamp lots. Zero martin housing (likely inhibited by homeowner codes), this development not included in this count..
These results based upon a trial run, later in the year I will go back to get more definite estimates of # cavities, make and age of housing, height, proximity of trees etc etc
Mike Scully
