Last year's birds
Fluff roosts
Fluff is usurped
A truly excellent site about these birds
Visitors since 17th September 2000:
18th April 2000. Today was another wet day; undeterred, the birds kept up their visits to the box, mostly with feathers.
19th April 2000. By contrast, today was fine and warm, with outdoor temperatures up to 14C. Between 2.30pm and 5.30pm there was frenetic building activity; we counted 36 visits bringing feathers in 2 hours, followed by many visits bringing straw. The nest box appears to be at least 6cm deep in material now. The bird did not return to roost this evening. We are not sure whether there is (the first) an egg buried deep in the nest material. Certainly, the female bird spent periods of up to 15 minutes at a time sitting in the nest, and encouraging entries by the male from time to time.
20th April 2000. Maundy Thursday. It is raining heavily again today. The bird is getting broody and sitting in the nest for increasingly lengthy intervals, in between collecting additional feathers and straw. Here we see her at 4pm, resting on the very-much-enhanced pile of nest materials. She looks exceptionally sleek and in "fine breeding condition". Jim Flegg in his book (op cit above) says that at this time her weight will be at its maximum, nearer 13 grams than the normal 11 grams. He also says that Parus caeruleus "almost invariably lay an egg a day - usually early in the morning - and almost invariably the female will conceal her first few eggs haphazardly in the loose nest fabric".
It is a pity that the exigencies of low-light-level infrared video photography don't allow us a colour picture.
21st April 2000. Good Friday. The bird has been in and out much of the (dry but windy) day with materials. This evening at 7.50pm, about 20 minutes before local sunset, she came in and sat after much worrying around in the nest. We wonder if she has laid an egg, but we can't see. Anyway, she has spent much time upside down, forming a deep cup into which she has subsided, to roost, at 8.25 pm. Therefore, for the two days 19th and 20th she did not roost, but has now come with serious intent.
22nd April 2000. Holy Saturday. The bird has now built a substantial and deep nest; here she is, almost buried, on the eve of Easter Day, with perhaps an Easter Egg tomorrow morning.
23rd April 2000. Easter day. There are still no visible eggs. This is reportedly (so far) the wettest April on record. Jim Flegg (op cit) says "sudden climatic changes - prolonged wet or cold weather on the one hand, or a warm sunny spell on the other - - can produce appreciable variation (in nest building time) from place to place and certainly from year to year." This must be a "late" year. Later, we deduce the first egg was indeed laid on Easter Day and promptly hidden from sight.
Here is our female bird, having just been calling to the male looking in at the hole, in the course of shaking and settling herself into the nest cup.
And here is the bird having a good snuggle down in the cup, but still not yet ready to roost.
The weather today has been fine apart from a 2.4mm burst of showery rain, and the temperature has been 15 Celsius.
At about midnight, the bird became very restless, preening and scratching itself and digging itself out of the nest cup.
This went on for well over an hour; from time to time the bird attempted to roost on the top of the nest cup, usually for only a few minutes at a time.
24th April 2000. Another wet day is forecast. We may observe the slow start to spring by comparing the oak buds on 18th March with their development today, 24th April. The birds are holding fire on their egg-laying to be sure of the correct stage of development of the oak leaves when the young hatch out. The oak leaves need to be immature and light green, to provide nutrients for the species of moth caterpillar which the bird feeds to its young; later on the leaves become darker green and replete with tannin, which is no good for the caterpillars. Timing is everything in this activity.
The first egg of the clutch in 1999 was laid on the 10th April, so our bird is nearly two weeks later.
26th April 2000. It is just possible, this morning, that we can discern three eggs through the plethora of nesting materials that the bird keeps shifting around. In this case, laying would have started on the 23rd April, which is 10 days later than the first egg reported from a Parus caeruleus nest in a nearby town.
At 6.50pm the bird came back, shifted around on the eggs and displayed the edge of one of them, see below....
Shortly later she departed, leaving a clear sight of four eggs.
27th April 2000. The morning's egg has arrived. This is number 5, and the bird is no longer hiding them when she leaves the box.
Here is the bird, looking large, sitting on the eggs, doing not very much else.
The bird spent most of today (27th) absent from the nest, having covered them with a thin layer of straw. She returned at 6.45pm, about 90 minutes before local sunset, and spend some time upside down, rearranging the nest cup around the eggs. Now is the time to speculate on the eventual size of the clutch of eggs. Nine? Ten? Eleven? In any case, laying should be complete in the first week in May, and hatching may then be expected about 20-22 May. So we may see the chicks leave the nest in the first or second week of June.
We are monitoring the temperature inside and outside the nest box. At present, 8.40pm with the bird roosting, the inside temperature is 13.7 Celsius and the outside temperature 11.3 Celsius. Normally, with an empty box, the thermometers track each other within about 0.7 Celsius depending on whether the outside temperature is rising or falling (there being some delay on the insulated thermometer in the base of the box). It will be interesting to track the egg temperature when the clutch is complete and the bird starts to brood.
28th April 2000. The bird may (probably has) have laid another egg this morning but she has hidden them so well that we can't see. This is common for these birds, early on in the clutch production process.
Evening of the 28th April, and the bird arrives at the outside of the nest-box, taking very little time to enter and settle for the night.
29th April 2000. The bird laid a seventh egg at about 05.40. Shortly afterwards, she left the nest, returning to be fed by the male.
A little while later an unwanted visitor arrived, and the bird adopted the defensive position of warning.
And then in a furious flurry of wings, drove off the visitor, aggressively.
Normality was then restored.
The new CCD camera took a colour picture of the bird emerging from the box at 10.45 am. Below, there is a shot which might be called "am I being watched?"
These two pictures were taken with a 300mm mirror lens on a CCD to M42 adaptor ring. Focus is critical; the depth being about 1 or 2 cm only at this range (f8 aperture).
Laying eggs must take energy. Our bird is spending a little longer each day in the nest box, sitting or roosting on the eggs. At 6pm, 140 minutes before local sunset, she has already settled for the night into the characteristic head-under-wing roosting position. The thermometers are now indicating a 3 degree Celsius temperature differential between the box and outside, when the bird is sitting. Jim Flegg (op cit) says that at about this time a "brood patch" develops on the female tummy, where the feathers are denuded and the blood supply enhanced. This may be reflected in the higher observed temperature difference.
30th April 2000. There are eight eggs this morning. The female bird has started to brood in earnest, only leaving the nest box for a few minutes at a time. Here is a picture of the male bringing her food at about 07.30am.
