Figure from preprint showing temporal chage in mass of great tits. In (A) plot is of average mass each year for adult birds during breeding season. In (B) the mass of nestlings in each year. The lower, purple line, are data for all nestlings; the green points and line for those nestlings which survived to be breeding adults. The increasing gap between the lines shows that selection on fledging mass has slowly become stronger over this period.

Young male Great Tit in the hand after processing to collect biometric data

Some new research from us, led by @davididiaquez.bsky.social. Using data from the past 47 years, we show that mass of adult great tits has declined by ~1 sd, which seems to result largely from an environmental effect on nestling growth linked to higher pop density

www.biorxiv.org/content/10.6...

Read now in @asn-amnat.bsky.social ahead of print! 🐦🌳

Thank you to co-authors @sheldonbirds.bsky.social, Josh Firth & Ella Cole, + support and many years of data collection @egioxford.bsky.social @biology.ox.ac.uk !

Our take-home is habitat quality better explains repeatable spatial demography, more so than age. The framework should be used in other systems, where we would expect stronger spatial age structure in longer-lived, lower-turnover species 🐦🌳 7/n

Why so little age clustering? Likely that high site fidelity among survivors coupled with high mortality & immigration → frequent territory turnover. This weakens any stable link between age and quality and erodes repeatable spatial age structure 6/n

We found very little consistent clustering of age in space. In contrast, habitat features were strongly spatially structured, and reproductive output showed modest spatial patterning. Spatial age patterns also shift from year to year 5/n

RESULTS! Older inds are more likely to occupy higher-density territories, & older males (not females) more often occupy sites popular in the longterm. There is little to no link between age and oak abundance or edge distance. Overall, only weak covariation between age and territory quality 4/n

We then asked (1) if territory quality predicts age & (2) whether age tends to cluster in space. We also compared this to how habitat features and reproductive success are arranged, and examined whether any of these spatial patterns are consistent across years 3/n

Using 45 years of data, we defined a territory around each breeding pair, also assigning the age of breeders to those territories. We described territory quality as: how crowded the neighbourhood was, oak density, distance to woodland edge, and how ‘popular’ the site is in the longterm 2/n

We propose four routes to spatial age structure: (1) annual shifts in population age distribution; (2a) older birds gaining higher quality territories; (2b) better territories increasing survival/tenure; (3) edges attracting younger immigrants 1/n

Great tit

New paper out, the last one from my PhD 🎓! Age shapes behaviour, survival, and reproduction. By using longterm great tit data, we ask whether age covaries with territory quality, and if territories show spatial age structure over time: tinyurl.com/ya2xp3zc

Scilly October 2025 I have recently started a full time teaching job in London, which alongside its many pleasures includes the fact that there is a 2 week October half-term which nicely coincides with a great time to...

Write up of my 6-day trip to Scilly! www.joewoodmanwildlife.com/blog/scilly-...
#ScillyBirds

Cracking end to my 6 days on Scilly, with a hoopoe on the garrison & a smattering of great shears, 2 sooties, 3 puffin and a bonxie from the Scillonian. 105 species total! Full trip report here: ebird.org/tripreport/4...
#ScillyBirds

What a day - lapand bunting in the morning, buff-bellied pipit and flyover whitefronts on St Agnes, and a bluethroat at Porth Hellick in the evening. Where else but Scilly
#ScillyBirds

Choose your fighter. Great white egret and grey heron at Porth Hellick yesterday afternoon.
#ScillyBirds

Slightly weird snipe at Peninnis today. Roosting in relatively open/dry patches. Didn’t flush as warily as other comm snipes, didn't call and less zigzagging flight. Sadly no diagnostic features for any vagrant species were seen. Probably just tired!
#ScillyBirds

Examples of some recent papers from graduate students in my group - a full list of recent papers and preprints can be found here (https://scholar.google.co.uk/citations?hl=en&user=pTdxVdIAAAAJ) and profile of the group here: https://egioxford.web.ox.ac.uk/members

The annual Wytham Field Team Photo!

Celebrating a successful field season with great food & good company - May 2025

Front view of the Life & Mind Building, which opened in Oct 2025: The new home of Biology at Oxford

Interested in a PhD in ornithology? Funding available for projects at the interface of ecology, behaviour & evolution from Oct '26 working on long-term population studies of tits at Wytham, based in @biology.ox.ac.uk in the new Life & Mind Building in Oxford
www.findaphd.com/phds/project...

Well (for all of 10 minutes…)! Light was quite low in the AM, and it was slipping in and out of undergrowth. But we had a solid ~2 minutes of uninterrupted views as it foraged c.20ft away before flying off - was very distinctive even in the dull conditions

Black redstart

Red-backed shrike

Little bunting

Greenshank

Very glad that becoming a teacher allows for an October halfterm trip to Scilly. Arrived yday, so far adding 8 spp to my Scilly list. Highlights have been RB shrike, little bunting, 3 redpoll over and ofc the Eyebrowed Thrush. Bring on the next 5 days!
#ScillyBirds

Great tits show early signs of splitting up: researchers uncover social clues to bird 'divorce'

Wild great tits signal ‘divorce’ long before the breeding season — even in the winter, months before the couples rebreed with different partners in the following spring

New study with @universityofleeds.bsky.social in @royalsocietypublishing.org 👇
bit.ly/4lRt7TN
@sheldonbirds.bsky.social

Wytham Woods: A Season in 3 Boxes YouTube video by Joe Woodman

Really enjoying my new job teaching Biology in London, but the sunny weather has me missing the early Wytham mornings during the field season 🌳
An old video I made of the '23 field season working for @egioxford.bsky.social & @biology.ox.ac.uk takes me back: www.youtube.com/watch?v=C-rm...

Yay congratulations Denise!!

Checklist Media is now live! ebird.org/news/new-che...

Scilly April 2025 I have just returned from another cracking week in Scilly. Last year was my first time visiting during the spring, and despite spending every summer in Scilly, I was surprised at how unfamiliar much.....

Write-up of my week in Scilly: www.joewoodmanwildlife.com/blog/scilly-...

#ScillyBirds #Birdwatching

Turnstones

Sanderlings

Colour-ringed sanderling

Sanderlings in flight

My happy place: shorebird-watching on Tresco as the tide pushes them inland in the morning sun. This year made even better by a colour-ringed sanderling, originally ringed as a juv in Pontevedra, Spain Oct 2020, and seen again in Syddanmark, Denmark Jul 2022
#ScillyBirds #Birds #BirdRinging

Shore lark

Great to catch the shore lark before leaving Scilly - a really scarce bird on the islands with this being the first since 2009 and one of only 13 in total
#ScillyBirds

Woodchat shrike

Female pied flycatcher

Dwarf pansy

Female common redstart

Great tramp around Bryher w/ Will @iwtscilly.bsky.social, inc catching up with the woodchat shrike found earlier. Also learnt lots more about Scilly's flora, including seeing the amazing dwarf pansy - found only in Scilly and essentially only within this approx 100m2 plot!
#ScillyBirds

Wryneck

Ring ouzel

Common sandpiper

Starling

V tough conditions for birding yday with high winds/rain, but in true Scilly fashion the weather flipped completely overnight. Kicked off w a self-found wryneck and a smattering of rouzels. Failed to catch up with the purple heron on St Marys, but it was a lovely day to walk around the island.

Manx shearwater

Very considerate of my sister to get married in July so our family holiday to Scilly has been brought forward to a much more birding-friendly April! Blustery/wet crossing on the Scillonian brought 100+ Manxies, as well as guillemots and razorbills. Looking forward to a week of birding!

Barn owl

Such a nice bird to catch up with locally, but not quite in the confines of my Brill village patch!