nest box saga

[watervole]

Much to my surprise, we now seem to have co-habiting birds.

Both blue tit parents are now visiting the box regularly and caterpillars are being delivered in a steady supply. I don't know which is the male and which is the female - blue tits all look alike to me - but one of them is *very* scruffy.

I heard the babies tweeting while I was working in the garden today, so I know they're okay.

Maybe there's something in the bird mindset that say "More eyes to watch for predators". After all, by the time the great tits have hatched eggs, the blue tits will have already fledged, so they're not direcly competing.

I just wish I knew if this is something that often happens. Most nest boxes are single nest size, so you never normally get something like this. I wonder what would happen if more garden nest boxes were larger? (this one is a three hole box for sparrows)

Comments

[communicator.livejournal.com]

gosh I've never heard of that before - when you told the story originally I was thinking 'there's nothing anyone can do about it, but nature can be very harsh' - so a pleasantly surprising outcome

[asphodeline.livejournal.com]

That does seem strange but a lovely outcome. Maybe they're sharing baby-sitting duties!

[temeres.livejournal.com]

I've never heard of anything like this before. Tits are not communal nesters by nature, though that might simply be because their natural nest sites - holes in trees - are not conducive to sharing. Some African sparrows nest communally, but they build their own nests in a tree rather than exploit a hole. (Ordinary House Sparrows tend to nest in close association with each other, though they can also adopt isolated sites away from other sparrows.)

I don't know to what degree Blue and Great Tits compete with each other for nestling food. Since even a tiny size difference can have an impact on preferred prey, it wouldn't suprise me if the two species exploited very different food resources, in which case it wouldn't bother either to be nesting in such close proximity to each other. I doubt if there's any mutual cooperation going on, though - the two pairs just happen to be shacked up in a space big enough to accommodate them both.

What surprises me most is that they haven't been ousted by sparrows, but given the precipitous decline of the sparrow population maybe that isn't so surprising.