Nestorations: Eight Things Recovered from the Nest

Last week we popped up to the osprey nest for our annual autumn nestoration visit.

Why disturb the nest?

Well, there are several reasons.

1. The most important reason is to secure the structural integrity of the nest. Monty and Glesni probably carry over 100Kg of material to the nest every year and this, especially when it's wet, puts a huge load on the nest material beneath it. We usually take away around two feet off the top layer of nesting material each year.

With winds of up to 100mph recorded on the Dyfi estuary during the winter months in some years, the nest could easily be weakened and become unstable and fall. Worse still, it could be structurally compromised in such a way that we don't notice, only for it to fall or break up in bad weather in April onwards once the ospreys are back; then we would be in all sorts of trouble - and so would Monty and Glesni.

The only way is up... then down

2. We have an opportunity to take anything that could be harmful away - see below.

3. We service and clean the cameras while we're up there.

4. We get to know exactly what is in the nest!

Eight things we found in the nest in 2015

1. String/Twine
Anything 'stringy' like baler twine or fishing tackle and lines can be harmful to birds for obvious reasons. Thankfully we don't see too much on the Dyfi, but we did retrieve this bit which is enough to kill an osprey if it managed to get caught up in it.

Thankfully, this osprey was rescued just in time in 2014 from a nest in Idaho. Many are not so lucky.

Osprey caught in twine on nest in Idaho, 2014 (rescued)

We did have a good look for that plastic ring that was in the nest for a few weeks (brought in actually around a fish), but alas couldn't find it.

2. Fish scales
Well, it sounds obvious doesn't it! These are mullet scales - there are thousands in the nest at the end of every season. In conjunction with 3 (below), Monty and Glesni leave us with an unforgettable smell every winter to remember them by.

3. Oh, Pat...
Along with dung beetles, ospreys have a penchant for cow pats.

Stop calling me Pat

4. Goose feathers
Ospreys like to bring feathers to the nest - crow feathers are favourites as well as these goose ones.

MWT - Goose feathers found in nest (2015)

5. Bones
Bones are another favourite, you may remember these in the nest from mid July onwards. We're not sure who they originally belonged to - maybe a fox or a Canada goose? What do you think? - certainly not sheep.

6. Osprey feathers
No lovely moulting primary feathers this year - we just found this one. Possibly a feather lost by Brenig in August - it was seen dangling off his wing after a sibling scuffle with Merin before finally being dislodged.

MWT - Osprey feather found in nest (2015)

7. Opercula
The 'operculum' is the bony covering which protects the gills of a fish. These are usually too big to eat and opercula are discarded by ospreys either in the nest or beneath feeding perches. We collect these every year and put them in our operculum box to show visitors and children the following season in the visitor centre.

8. Bark
Ospreys often bring bark back to the nest as a rasp-like material to gnaw down their beaks and talons on - nature's own nail file. Other materials we've found over the years that act in the same way include stone, bits of metal, and slate - naturally!

Many thanks to all the volunteers that helped us at the nest site last week, especially Sarah who climbed the ladder and got her hands dirty - quite literally.