2018 Birch log blue tits: The odds were stacked...

Our first bluetits hatched on the day of the Royal Wedding, so the first pair were predictably named Harry and Megan.  We were lucky enough to catch one at the point of hatching, the sequence below is speeded up a bit:

Others  followed soon enough...

day 1-2 , all looking good....

We had noticed previously, that the female bluetit had a tick next to her right eye, but didn't think much of it, since we all have to contend with the nasty critters.

Tick below right eye.  Really.

The tick disappeared within a few days, but she proceeded to have a fairly dramatic reaction with a lot of swelling around the eye which was also accompanied with feather loss; she was practically bald on the right side of her head.

Adding to her woes, the male appeared to have left the scene, so we had a one-eyed single mother with 5 yet-to hatch + 3 chicks to look after... not looking so good...

She was managing for a couple of days, but fell into a pattern where eggs would hatch and within a few days the new chicks died.  Megan and Harry were hanging in there though.

Food was varied, we saw a lot of huuuuge caterpillars / grubs that are not going anywhere (except maybe by tunnelling their way out).

Some sibling rivalry in the next clip, with Harry and Megan are fighting over a caterpillar...
You can see ?tick-related feather loss on the adult's head quite well here too.

When the adult feeds, she takes turns in selecting which chick gets fed.  One chick really wants to hang onto the food and gets flung about a bit.  An avian version of the magnetic fishing game.

As this is our first (semi) successful nest for several years, I'm not sure if the next clip showing a chick on top of its mother is normal behaviour, but she sometimes doesn't get the idea of sitting on the chicks to keep them warm...

The lack of a second adult, together with her erratic feeding lead to the inevitable deaths, while Harry and Megan soldiered on.  This clip shows her removing one of the smaller chicks that didn't make it.

Another observation from this nest was that there seemed to be quite a range of hatching intervals. Some chicks were hatching up to a week after the 'Royal pair'.  If this was an owl nest I could understand the concept of a spare/(?heir) or one saved for a lunch snack.  One theory I suppose could be that staggered hatching times maximises the chance of at least some surviving a short period of limited food.

Three big, one small.  

..so fast forward to day 6.  She removed 3 more dead chicks between 8:00 and 8:30 am, leaving two unhatched eggs and our original pair, Harry and Megan.

By this point, her right eye is looking seriously, well wrong...  I'm fairly sure this is tick-induced, however the tick itself appears to have gone.

Unsuccessful attempts at feeding include very large grubs and sunflower seeds (presumably from our feeder...)

In the end the female bird failed to overnight in the box and the Megan and Harry didnt make it through the Friday night.  She was back in the morning, even attempting to feed the dead chicks..

This clip is a great example of the 'cycle of life', so even if this nest has failed it still feeds the maggots, who in turn into flies to feed something else....

After clearing the last chick out (?Harry/?Megan), she did attempt to incubate for day or so, but eventually left.  We haven't seen her since.  We're hoping that she can recover from her tick injury without having to feed a brood.

So currently our BirchBox next box has this in it.  Black ants have finished off the cleaning up that the wrigglies missed:

Take two...

• Days 1-14 of this nest are described here