My wife's Discovery 4 went for a service yesterday, with me mentioning that it seemed hesitant and down on power. When the car was dropped back it was accompanied by this - all found in the airbox.

Click image to enlarge

One more reason to have the air filter renewed every year instead of every 2 according to the official LR schedule  Visitor from fullfatrr.com
* GONE. 2012 RR Sport HSE SDV6 Orkney Grey. Now being piloted by RRSTDV8
* GONE: 2011 4.4 TDV8 Full Fat. Amazing piece of kit.
* Current. 1974 Lightweight 2.25L petrol. Old skool
* GONE. Freelander GS TD4 Manual MY2013. Orkney Grey with privacy, cold and clearview packs, armrests (a must!) and a spoiler.
* GONE. Range Rover Classic '93 200Tdi Factory fit
* 1949 80" in family since 1975

We had pair of Bluetits nesting in our garden and they have used the moss to fill it like the photo, so could be bluetits and they are small enough as well.

It must have taken quite a few trips to move all that moss. I wouldn't mind, but I put some bird-boxes in the garden last year.

I had a similar occurrence with my Defender a couple of years ago. I had been off-roading and a branch had taken out the plastic grille over my Safari Snorkel. On the way home I had put up a flock of Blue Tits who had been on the road and was sure I had hit one but there was no sign of any floating feathers in my wake or a small body on the road so I thought no more of it thinking the bird must have had a "near miss" type experience. A few months later the TDi300 started to suffer a lack of power and I took it to the local specialist to investigate ............ I got a phone call a couple of days later accusing me of being a mass murderer, my Defender had managed to invest not only the Blue Tit but somehow a Field Mouse as well and both had perished at the bottom of the snorkel blocking the air intake. The only way the mouse could have got in was while the car was in storage at my father's industrial unit where we knew there were a few field nice as my mother keeps seeds and peanuts for feeding the wild birds in bulk bags and they had nibble marks on them. The suspicion was the mouse had smelled the decomposing Blue Tit and gone to investigate, climbed up the snorkel and in through the hole in the intake grating and fallen down inside....... the bodies were found by the specialist. He replaced the plastic intake grille with a stainless steel one - no more nice and no more blue tits! 2020 Pangea Green 1st Edition D240 New Defender 110 is here and loving it
2018 Melting Silver Mini Countryman PHEV - soon to be replaced
2015MY Corris Grey SDv6 HSE Dynamic, the best car I have ever owned, totally reliable only a cou0le of rattles in 3 years, now no longer in my care
Also in my garage is a 1996 TDi300 Defender 90 County HT made into a fake CSW

If the mouse went in after the bird, shouldn't the next step to have been to send in a cat after the mouse?

It is amazing how much power you loose when something so small blocks the air intake.......... Regarding the cat, my parents were between cats at the time! There was once an old woman who swallowed a fly, don't know why............ remember that song from a long time ago - a Val Doonigan hit I think Giving my age away again... 2020 Pangea Green 1st Edition D240 New Defender 110 is here and loving it
2018 Melting Silver Mini Countryman PHEV - soon to be replaced
2015MY Corris Grey SDv6 HSE Dynamic, the best car I have ever owned, totally reliable only a cou0le of rattles in 3 years, now no longer in my care
Also in my garage is a 1996 TDi300 Defender 90 County HT made into a fake CSW

...if it gets as far as a horse, then it's probably being worked on by a LR dealership  Robin
2008 Range Rover Sport TDV8
Gone:
Jaguar S-Type V8 4.2 Sport
MGZTT 190 2.5

Our Land Rovers have resident 'Land Rover Spiders'. My RRS has one in the wing mirror and my wife's D4 has one that lives inside at the top of the A pillar. One seemed to disappear and in the end we had to get a Britpart replacement as the OEM spiders from the dealer were too expensive (not to mention 2 man-hours for the installation and re-programming the management computers).

I have resident spiders too on both the RRS and the Defender - the Defender one seems to like the rugged outdoor life as it builds webs between the uncowled/unheated wing mirror and the door mount, the RRS one must be a softy as it lives in the wing mirror cowling. I also have several spiders living in the rear spoiler area! How green is that - a mobile nature reserve in every car! My 1st Evoque was a Fuji White Coupe and that was a heaven for millions of little black flies when it was parked on my drive, I don't know what the attraction was - might have been whatever GardX added to their paint protection scheme polishes but I had never experienced that before on any car and haven't had it on the cars I have owned since. 2020 Pangea Green 1st Edition D240 New Defender 110 is here and loving it
2018 Melting Silver Mini Countryman PHEV - soon to be replaced
2015MY Corris Grey SDv6 HSE Dynamic, the best car I have ever owned, totally reliable only a cou0le of rattles in 3 years, now no longer in my care
Also in my garage is a 1996 TDi300 Defender 90 County HT made into a fake CSW