29 April 2010

Bird-brained

People often mention how amazing it is that, as soon as they leave the nests, birds seem to know exactly what they're doing. They can fly--many migrating long distances within a few months of hatching--and most are capable of finding their own food within a matter of days, unlike useless humans.

So, it's refreshing to know that sometimes, even birds can get it wrong. The BTO's Nest Record Scheme has received two reports this spring of birds that get an A for effort, but an F- for design, when it comes to building their nests.

Within days of nest recorder Graham Uney putting up a sparrow terrace, consisting of three nesting compartments in a row, a pair of Great Tits started building inside. Unfortunately, this particular pair couldn't seem to make their mind up which was the most desirable chamber and ended up building nests in all three, laying two eggs in two of them and a single egg in the third. Even if the male lends a hand during incubation, a degree of chivalry previously unheard of in the Great Tit world, they're still going to need to find a baby-sitter.

What number was it again? At least this episode confirms that Great Tits can't count either...

Not to be outdone, a Long-tailed Tit pair monitored by Jim Hodson spent a good few weeks constructing their intricately woven nest using moss, lichen and spider webs, but failed to spot a minor flaw in their design - they forgot to put a hole in it! Cue a hasty reconstruction job six inches away, using the old nesting material.


A Long-tailed Tit nest is a distinctive dome with, usually, a hole near the top (left in this picture).

We're just as interested to hear about birds getting it right, so if you've found a nest that you can see into to monitor, please contact us at nrs@bto.org for a free Starter Pack, or send us the details on-line at www.bto.org/nbc

Dr Dave Leech
Head of the Nest Record Scheme

2 comments:

  1. At 4AM getting up for 1st CES in the dark this is funny.

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  2. I reckon I had a similar situation to the GRETI's with a pair of swallows last year. First brood I had two nests on adjacent beams c1m apart with 3 eggs laid in one nest and 2 in the other. The nest with 3 eggs was incubated and fledged 3 young but there was no sign of incubation or embryo development in the nest with 2 eggs. For the 2nd brood - same room but two different nests on adjacent beams on the opposite side of the room to the original nests (so probably the same pair)3 eggs were laid in one nest and one egg in the other. The nest with 3 eggs was incubated and fledged 3 young but again the adjacent nest with one egg showed no sign of incubation or embryo developement.

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