Author: allyphillimore

We track tree, invertebrate and bird phenology, and to do so, we collect data from 44 sites along a 220 km long transect in Scotland. To find our more about our fieldwork and how that links to our research objects, you can watch the Phenoweb video below. A huge thank you to Gergana for putting this video together.

This year we had four new sites. We also increased the number of nestboxes to 8 at many sites, which takes the total up to 334.

Winding roads along the transect

A nestbox

The first egg was on April 10^th, making this our earliest year yet. A very noticeable pattern was that the egg laying was a fair bit earlier in the south than the north, which marks a reverse of trends we’ve seen in previous years. Trees also seemed to be a bit slower to come into leaf in the north this year. You may also be able to pick out a trend for later breeding as elevation increases and this is a pattern that we see every year and which must be associated with temperature.

A blue tit nest

Birch leaves opening up

The breeding season began quite well with the earliest sites fledging quite a few young. However, a spell of really foul weather around June 6^th led to quite a lot of nest failure – due to heavy rains preventing the adults from foraging.

Across the entire transect 949 blue tit young were fledged.

By ringing the nestlings and adults we’re learning quite a bit about their movements. Very often we find it’s the same pair at a nest in each year. We’ve also found cases of birds moving between sites – sometimes up to 15 miles away from where they hatched.

We’ve had a great field season and are looking forward to analysing all the data we’ve collected!

Disclaimer: All blue tit adults and young were handled by licensed individuals with the appropriate permits.

As the field season comes to an end, I’ve been reflecting on the many great aspects of getting to be part of the Phenoweb project. Here are the moments that particularly stood out for me.

The routine. It can be daunting to start a new job, go to places you’ve never been before in search of specific trees, nestboxes and branches. Of course, we had maps and a very supportive team, but I still enjoyed the moment when we really had our routine down – we would arrive at a site and know exactly where we have to head, we would find the branch where we are mean to count invertebrates straight away.

The surprises. Of course, it was great to have some surprises, too! My personal favourite was when I dropped the plastic bag for branch beating and lifted it up only to find a beautiful fawn curled up among the bluebells. A truly fairytale moment. Another surprise was a really snowy day we had in late April. Remember that smooth routine we had? Well, we quickly got reminded of what finding the trees and branches was like in the very beginning of the field season, as that day in April, everything was covered in snow, hiding the string we use to flag trees and the current status of tree buds (as you couldn’t see them).

A surprise winter wonderland

Snowy views by the loch

The new skills. I love the feeling of having learned something new, and there is plenty to learn along the transect – tree identification, bird handling and ringing, branch beating. I had never thought of the date as “day 113 of the year” before, but quickly we stopped thinking about Mondays and Tuesdays, with questions like “What day is it today?” immediately followed by a number.

The new places. Thanks to working on the transect, I got to see much more of Scotland than I had before. The north sites were my favourite – such beautiful scenery! An inspirational place to work.

Pretty sights near Dornoch

Pretty sights near Dornoch

The little stops along the way. During the field season, I learned a lot, I felt inspired and motivated to continue pursuing science, and I had fun. I also had the best fudge donuts of my life, ate delicious cake and scones, took in the sounds of spring as we quietly had lunch or chatted away on one topic or another. Fieldwork along the transect truly is about the journey and the stops along the way, and what a journey it’s been!

Little peaceful moments

By Gergana

Over the last couple of months, we have seen many blue tits – as chicks begin to hatch, each site abounds in blue tits. Though of course blue tits are a lovely sight, we have been lucky to spot a lot of other wildlife along the transect, too. We get to spend most of the day outside, field notebook at hand, recording phenology and measures of bird fitness. Meanwhile, dippers are dashing up and down streams, sometimes even a tawny owl is looking down at us, and often it’s all happening in a magical fairytale-like setting of an woodland, carpeted in bluebells.

A particularly fairytale-like moment was when we walked over to a nestbox only to find a fawn curled up among the bluebells. Magic! Of course, we quietly checked the nestbox and quickly moved away to avoid disturbance, but we’ll definitely remember seeing the fawn (aka Bambi The Bluebell) for years to come!

One day, we got up even earlier than usual in hopes of seeing a capercaillie. Well, that didn’t happen, but nevertheless, we’ve had some pretty exciting bird sightings. There’s a tawny owl at two of our sites, and we spotted a long-eared owl near another. A pair of northern wheaters greets us as we drive down a small country road towards another another site.

Long-eared owl

A well-camouflaged tawny owl

Northern wheater

Some of us on the field team saw black grouse for the first time, but regardless of whether we had seen them before or not, we all find seeing and hearing the grouse thrilling.

Black grouse

Black grouse

Then there are also the golden eagles – or so Gergana has heard, she didn’t spot any, thus no eagle photos.

Since the establishment of the transect in 2014, we’ve seen 141 bird species at our sites or directly between sites along the transect. Most of us on the team spend a lot of time working away on computers, so the field season presents a wonderful opportunity to get outside, collect data, and get inspired by nature in the meantime.

Our days are packed with branch beating and counting invertebrates, weighting and ringing chicks and looking up the occasional tree that is not in full leaf out yet (like all the aspens!). You can definitely tell it’s peak season – the spreadsheets and field notebooks are filling up, adult blue tits are dashing in and out of nestboxes feeding their chicks.

Weighting blue tit chicks

Blue tit chicks

Blue tits are busy, and so are we! Here is a video of an adult blue tit coming in and out of the nest – if you listen closely, you can hear the blue tit song getting closer and closer.

We have been counting more and more caterpillars, and they are getting bigger. Every once in a while we spot particularly sparkly beetles, too. It feels really rewarding to go to bed after a jam-packed day of fieldwork, knowing that we’ve collected lots of data, spent time outside and worked smoothly as a team!

A winter moth caterpillar

Branch beating

Disclaimer: All blue tit adults and chicks are handled by licensed individuals with ringing permits.

Fieldwork is well underway. We have been walking through the Scottish woodlands as spring is gradually arriving all around us – tree buds opening, blue tits singing. Our days start early, sometimes with tea, more often with coffee. We are working in two teams – one in the south part of the transect, one in the north. The best part is when we meet in the middle and get to exchange stories about what happened during the day.

The first few days of trying to find the marked trees (think finding a needle in a haystack is hard, try a bright pink string in a brown-ish woodland…) are behind us – the trees and nestboxes are a familiar sight by now, and we’ve fallen into a nice routine. It’s actually a pretty special kind of repetitiveness to get to go to the same site, same trees and nestboxes week after week – there are so many little moments of natural wonder for which we have developed an appreciation.

Measuring nest height

Recording observations

Working on the transect is brilliant. I love the diversity of each site, and watching spring arrive day by day is a real treat. It’s so exciting to arrive at a site to check how the season has progressed and find that buds have burst on a new tree species or that there are new eggs in a nest.

Kat Keogan, Field assistant

For us, each day is a roadtrip. The destinations are the same, but each time we visit them, they are a tiny bit different – our job is to spot those differences and turn them into data on fitness (the survival of the blue tit chicks) and phenology. Phenology refers to the timing of life events, for example when trees first open up their buds, or when blue tits lay their first egg for the season.

Pretty scenery along the transect

Limes opening up their leaves

There is still much more of the field season to come, so where will our roadtrips take us? Ultimately, to a better understanding of how the blue tit phenological optimum varies across space and time. Along the way, we’ve been to places in Scotland we hadn’t seen before, we’ve honed our tree identification and data collection skills, and we’re excited for what the rest of the field season has in store for us.

Spring is just around the corner, the vans are packed, we are ready to kick off another field season along the Phenoweb transect. We will visit sites every two days through the spring, recording various phenological and fitness measures. The project was set-up to explain spatiotemporal variation in blue tit (Cyanistes caeruleus) breeding phenology and fitness and it provides the empirical backbone to this proposal.

Bluebells starting to pop up along the transect

Looking up to check if there are any open tree buds towards the top of the tree

The transect stretches 227km from Edinburgh (55.98°N) to Dornoch (57.89°N). In addition to a latitudinal gradient, the transect incorporates an elevation range from 0 – 450m, a temperature range of ~3.5°C and a variety of woodland habitats. At each site we have six to eight 26mm hole nestboxes, which exclude larger passerines such as great tits, and two thermochron i-buttons, which record accurate hourly temperatures.

Measuring nest height – this one already has fluff!

Blue tits returning to the nest boxes

We are excited to observe and record the arrival of spring in Scottish woodlands and will be sharing more of our experiences along the transect as the season progresses.