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Today saw the end of our 2020 Wood Warbler / Bonelli’s Warbler #fieldseason! It wasn’t always a personally gratifying year, but it was definitely a good one. Between 2 people, we found >90 #nests!!! A thread of some highlights: (1/n)
On the whole, we had very few nests of the former and an abundance of the latter. The low rodent density may have been the indirect cause for the relatively high naïve nest survival rates we saw. Here, my first WW #nest if the season. (2/n)
Interestingly, despite having the longer migration, WWs had the first and the last nests of the season; their breeding got underway sooner and they persisted longer than BWs. We also saw a WW nest with 8 eggs this year!!!! (3/n)
That’s not to say Bonelli’s Warblers weren’t pushing themselves — I found a nest with 7 BW #nestlings in it, the most we’ve seen yet. (Maybe also a response to low rodent densities?) I don’t usually remove all nestlings, but upon first finding the nest, I needed to count! (4/n)
Sadly, that nest, like most nests on that given hillside, was predated. We put trail cameras at most of our nests to observe fledging/failing, which resulted in this #epic #commonbuzzard shot: (5/n)
Weather was a challenge this year. Bouts of heavy rain and drops on temp likely made provisioning extra hard for adults. At least 2 nests appeared to have nestlings starve - I won’t include pictures here. We also had nests where adults stopped attending. Adult predation? (6/n)
On the other hand, as mentioned, naïve nest survival was among the highest we’ve ever seen, despite low #woodwarbler settlement. It was lovely to check up on a nest and see some big ol’ nestlings looking back! Here, #bonelliswarbler babies: (7/n)
And here, Wood and Bonelli’s Warblers being carefully handled for ringing (I have a permit; don’t handle birds without one!): Their throats colours give their IDs away! (8/n)
My colleague (not on twitter) even found an apparent Wood Warbler x Bonelli’s Warbler #hybrid!!!!!!!! She called like both and looked like a Bonelli’s with a hint of Wood mixed in (e.g. yellow-tinged throat). I’ll share pictures once it’s confirmed. 
(9a/n) #phylloscopus
(9a/n) #phylloscopus
((She thought she was a Bonelli’s and had paired to one — although with our very low Wood Warbler densities, that may have been inevitable. 9b/n))
Amazing how quickly these #birds develop... although these pictures aren’t of the same nest, they show the different that about 8 days of development make!!!! Especially important for ground-nesting birds like Bonelli’s and Wood Warblers. (10/n)
Finally, just some miscellaneous pictures from the season: (11/n)
Aaaand I’ll wrap things up with a few #woodwarbler #nests, because I’m horribly biased and they’re my favorites (even though I only had 6 females breeding on my sites this year!): #teamsibilatrix (12/n)
Last but not least, huge thanks and massive gratitude to @SLuepold @vogelwarte_ch @Vogelwarte_scie for another field season! It’s my 4th on the project and I keep coming back for the birds and the support and the science. What a great group to be a part of!!!! (14/14)
Oops I can’t count. So now here’s the 14th tweet to justify that n/14 
