Bart Hoekstra
@barthoekstra.bsky.social
Movement Ecology PhD candidate @ IBED, University of Amsterdam | Radar Aeroecology | Birds | Energy | Climate | Monitoring & Comms. @batumiraptorcount.org | Remote Sensing | Open Science | He/Him | barthoekstra.com
To reduce negative impacts of #renewables (eg #windenergy) on migrating birds, we need to know *where* and how *high* they fly. Using weather radar, we mapped 6yrs of nocturnal migration over the Netherlands, revealing patterns we can use to avoid and minimize impacts:
doi.org/10.1016/j.je... 🧪🪶
doi.org/10.1016/j.je... 🧪🪶
October 30, 2025 at 12:58 PM
To reduce negative impacts of #renewables (eg #windenergy) on migrating birds, we need to know *where* and how *high* they fly. Using weather radar, we mapped 6yrs of nocturnal migration over the Netherlands, revealing patterns we can use to avoid and minimize impacts:
doi.org/10.1016/j.je... 🧪🪶
doi.org/10.1016/j.je... 🧪🪶
170K raptors! 🤯
8 yrs in the making, but I’ve finally witnessed a 100k+ raptors day while on the station actually counting the bulk of it. Incredible experience. Still feeling cross-eyed from staring through the scope non-stop for almost 10hrs.
📸: the Shuamta team at the end of this incredible day
8 yrs in the making, but I’ve finally witnessed a 100k+ raptors day while on the station actually counting the bulk of it. Incredible experience. Still feeling cross-eyed from staring through the scope non-stop for almost 10hrs.
📸: the Shuamta team at the end of this incredible day
October 2, 2025 at 5:42 AM
170K raptors! 🤯
8 yrs in the making, but I’ve finally witnessed a 100k+ raptors day while on the station actually counting the bulk of it. Incredible experience. Still feeling cross-eyed from staring through the scope non-stop for almost 10hrs.
📸: the Shuamta team at the end of this incredible day
8 yrs in the making, but I’ve finally witnessed a 100k+ raptors day while on the station actually counting the bulk of it. Incredible experience. Still feeling cross-eyed from staring through the scope non-stop for almost 10hrs.
📸: the Shuamta team at the end of this incredible day
Tomorrow at #CWW2025 I’ll present new work on using weather radars (the ones you check for 🌧️) to map nocturnal bird migration to support wind energy planning.
Join my talk at 11:30 (Auditorium Pasteur) to see how this can improve impact assessments and enable a more nature-inclusive energy future.
Join my talk at 11:30 (Auditorium Pasteur) to see how this can improve impact assessments and enable a more nature-inclusive energy future.
September 8, 2025 at 3:10 PM
Tomorrow at #CWW2025 I’ll present new work on using weather radars (the ones you check for 🌧️) to map nocturnal bird migration to support wind energy planning.
Join my talk at 11:30 (Auditorium Pasteur) to see how this can improve impact assessments and enable a more nature-inclusive energy future.
Join my talk at 11:30 (Auditorium Pasteur) to see how this can improve impact assessments and enable a more nature-inclusive energy future.
I've been interested in uncertainty visualization for a long time, yet somehow it took forever to come across this 2018 paper on ‘value-suppressed uncertainty palettes’.
A neat and intuitive alternative to the clunky ‘unsuppressed’ bivariate palette approach:
doi.org/10.1145/3173... 🧪 #dataviz
A neat and intuitive alternative to the clunky ‘unsuppressed’ bivariate palette approach:
doi.org/10.1145/3173... 🧪 #dataviz
July 4, 2025 at 7:59 AM
I've been interested in uncertainty visualization for a long time, yet somehow it took forever to come across this 2018 paper on ‘value-suppressed uncertainty palettes’.
A neat and intuitive alternative to the clunky ‘unsuppressed’ bivariate palette approach:
doi.org/10.1145/3173... 🧪 #dataviz
A neat and intuitive alternative to the clunky ‘unsuppressed’ bivariate palette approach:
doi.org/10.1145/3173... 🧪 #dataviz
Still buzzing from this weekend’s festival on Amsterdam’s closed ring road, part of the city’s 750th birthday celebrations. A unique chance to share our science and all about the birds 🪶 moving in and above the city. It's not every day you get to do #scicomm 🧪 at a festival w/ 250,000 attendees!
June 23, 2025 at 7:13 PM
Still buzzing from this weekend’s festival on Amsterdam’s closed ring road, part of the city’s 750th birthday celebrations. A unique chance to share our science and all about the birds 🪶 moving in and above the city. It's not every day you get to do #scicomm 🧪 at a festival w/ 250,000 attendees!
Feeling incredibly lucky to have these young Peregrines tearing through the skies around my apartment lately — sharpening their flight skills a little more each day. What a show. 🪶 #birdphotography #urbanwildlife
June 16, 2025 at 7:40 PM
Feeling incredibly lucky to have these young Peregrines tearing through the skies around my apartment lately — sharpening their flight skills a little more each day. What a show. 🪶 #birdphotography #urbanwildlife
Is this the largest tree in the Amazon? ~60m in diameter, likely 50m tall, an absolute behemoth identified via #remotesensing. What an incredible feat of nature. 🤯
ctrees.org/news/largest...
ctrees.org/news/largest...
January 2, 2025 at 12:22 PM
Is this the largest tree in the Amazon? ~60m in diameter, likely 50m tall, an absolute behemoth identified via #remotesensing. What an incredible feat of nature. 🤯
ctrees.org/news/largest...
ctrees.org/news/largest...
In other words: think of the birds 🪶 next time you light fireworks! 🎆🙏
Want to see what the radars show during NYE in The Netherlands. Here we show NYE radar imagery across many years: horizon.science.uva.nl/fireworks/in...
Want to see what the radars show during NYE in The Netherlands. Here we show NYE radar imagery across many years: horizon.science.uva.nl/fireworks/in...
December 30, 2024 at 11:17 AM
In other words: think of the birds 🪶 next time you light fireworks! 🎆🙏
Want to see what the radars show during NYE in The Netherlands. Here we show NYE radar imagery across many years: horizon.science.uva.nl/fireworks/in...
Want to see what the radars show during NYE in The Netherlands. Here we show NYE radar imagery across many years: horizon.science.uva.nl/fireworks/in...
Or, we could move towards using more ‘silent fireworks’, drone shows, or something else entirely, such as this ‘organic fireworks’ by Studio Roosegaarde www.studioroosegaarde.net/project/spark — Let's find ways to celebrate the next year more sustainably!
December 30, 2024 at 11:15 AM
Or, we could move towards using more ‘silent fireworks’, drone shows, or something else entirely, such as this ‘organic fireworks’ by Studio Roosegaarde www.studioroosegaarde.net/project/spark — Let's find ways to celebrate the next year more sustainably!
Then there are rare examples of 100s to 1000s of birds crashing to their deaths in mass mortality events after they're startled by fireworks.
For example:
Beebe, Arkansas: edition.cnn.com/2012/01/01/u...
Rome, Italy: apnews.com/general-news...
For example:
Beebe, Arkansas: edition.cnn.com/2012/01/01/u...
Rome, Italy: apnews.com/general-news...
December 30, 2024 at 11:13 AM
Then there are rare examples of 100s to 1000s of birds crashing to their deaths in mass mortality events after they're startled by fireworks.
For example:
Beebe, Arkansas: edition.cnn.com/2012/01/01/u...
Rome, Italy: apnews.com/general-news...
For example:
Beebe, Arkansas: edition.cnn.com/2012/01/01/u...
Rome, Italy: apnews.com/general-news...
But are there differences between species groups?
Yes, broadly speaking: in habitats with larger-bodied birds (think: geese, ducks, crows, gulls) the flight response due to fireworks is stronger than in habitats with smaller-bodied birds (think: thrushes, finches and tits)
Yes, broadly speaking: in habitats with larger-bodied birds (think: geese, ducks, crows, gulls) the flight response due to fireworks is stronger than in habitats with smaller-bodied birds (think: thrushes, finches and tits)
December 30, 2024 at 11:06 AM
But are there differences between species groups?
Yes, broadly speaking: in habitats with larger-bodied birds (think: geese, ducks, crows, gulls) the flight response due to fireworks is stronger than in habitats with smaller-bodied birds (think: thrushes, finches and tits)
Yes, broadly speaking: in habitats with larger-bodied birds (think: geese, ducks, crows, gulls) the flight response due to fireworks is stronger than in habitats with smaller-bodied birds (think: thrushes, finches and tits)
During NYE the radar measures on average 1000X more birds in the sky than on regular nights, with local peaks up to 10,000X to 100,000X more birds!
Also, fireworks disturbance is REALLY widespread. Up to 10 kilometers (6.2 miles) from fireworks bird numbers are still 10X higher 🤯
Also, fireworks disturbance is REALLY widespread. Up to 10 kilometers (6.2 miles) from fireworks bird numbers are still 10X higher 🤯
December 30, 2024 at 11:05 AM
During NYE the radar measures on average 1000X more birds in the sky than on regular nights, with local peaks up to 10,000X to 100,000X more birds!
Also, fireworks disturbance is REALLY widespread. Up to 10 kilometers (6.2 miles) from fireworks bird numbers are still 10X higher 🤯
Also, fireworks disturbance is REALLY widespread. Up to 10 kilometers (6.2 miles) from fireworks bird numbers are still 10X higher 🤯
What can the radar tell us? Well, just after midnight the radar ‘lights up’ because almost 400,000 (!!!) birds 🪶 immediately flee to the sky! Over about an hour, looking at the entire country, MILLIONS of birds are seriously disturbed by fireworks.
Dive in right away? 🧪: doi.org/10.1002/fee....
Dive in right away? 🧪: doi.org/10.1002/fee....
December 30, 2024 at 11:03 AM
What can the radar tell us? Well, just after midnight the radar ‘lights up’ because almost 400,000 (!!!) birds 🪶 immediately flee to the sky! Over about an hour, looking at the entire country, MILLIONS of birds are seriously disturbed by fireworks.
Dive in right away? 🧪: doi.org/10.1002/fee....
Dive in right away? 🧪: doi.org/10.1002/fee....
To answer these questions, we've now combined data from the @knmi.bsky.social weather radars with nationwide bird counts gathered by 100s of volunteers for @sovonvogels.bsky.social.
Combining both we can tell where birds actually are, where they are fleeing from fireworks and where they are not.
Combining both we can tell where birds actually are, where they are fleeing from fireworks and where they are not.
December 30, 2024 at 10:59 AM
To answer these questions, we've now combined data from the @knmi.bsky.social weather radars with nationwide bird counts gathered by 100s of volunteers for @sovonvogels.bsky.social.
Combining both we can tell where birds actually are, where they are fleeing from fireworks and where they are not.
Combining both we can tell where birds actually are, where they are fleeing from fireworks and where they are not.
Another NYE, another night of terror for millions of birds across the Netherlands (and around the world).
Last year we published in @ecologicalsociety.bsky.social Frontiers 🧪 about the massive impact of fireworks on birds 🦅.
Paper: doi.org/10.1002/fee....
Thread below 🧵👇
Last year we published in @ecologicalsociety.bsky.social Frontiers 🧪 about the massive impact of fireworks on birds 🦅.
Paper: doi.org/10.1002/fee....
Thread below 🧵👇
December 30, 2024 at 10:55 AM
Another NYE, another night of terror for millions of birds across the Netherlands (and around the world).
Last year we published in @ecologicalsociety.bsky.social Frontiers 🧪 about the massive impact of fireworks on birds 🦅.
Paper: doi.org/10.1002/fee....
Thread below 🧵👇
Last year we published in @ecologicalsociety.bsky.social Frontiers 🧪 about the massive impact of fireworks on birds 🦅.
Paper: doi.org/10.1002/fee....
Thread below 🧵👇
Was reminded by FB, I posted this picture 9 years ago. My all-time favourite picture of a Bearded Reedling, from an intimate photography session on a bitterly cold, foggy December morning. Bittersweet too as part of the already tiny area is now being converted into a highway.
#birdphotography 🪶
#birdphotography 🪶
December 20, 2024 at 12:34 PM
Was reminded by FB, I posted this picture 9 years ago. My all-time favourite picture of a Bearded Reedling, from an intimate photography session on a bitterly cold, foggy December morning. Bittersweet too as part of the already tiny area is now being converted into a highway.
#birdphotography 🪶
#birdphotography 🪶
Our @batumiraptorcount.org Autumn Report is now online!
Ever considered coming to Batumi to watch the incredible migration of 1+ million raptors 🦅, either as tourist or volunteer? Let our richly illustrated reports convince you to come next year.
www.batumiraptorcount.org/autumn-repor...
🪶
Ever considered coming to Batumi to watch the incredible migration of 1+ million raptors 🦅, either as tourist or volunteer? Let our richly illustrated reports convince you to come next year.
www.batumiraptorcount.org/autumn-repor...
🪶
December 18, 2024 at 10:44 AM
Our @batumiraptorcount.org Autumn Report is now online!
Ever considered coming to Batumi to watch the incredible migration of 1+ million raptors 🦅, either as tourist or volunteer? Let our richly illustrated reports convince you to come next year.
www.batumiraptorcount.org/autumn-repor...
🪶
Ever considered coming to Batumi to watch the incredible migration of 1+ million raptors 🦅, either as tourist or volunteer? Let our richly illustrated reports convince you to come next year.
www.batumiraptorcount.org/autumn-repor...
🪶
Happy to say that this year's @batumiraptorcount.bsky.social Autumn Report will be bigger, better and more beautiful than ever. Coming soon.
Making it has inspired me to share more of my #raptor #birdmigration photography here, so a teaser of some of the pictures I've contributed this year. 🪶🦅
Making it has inspired me to share more of my #raptor #birdmigration photography here, so a teaser of some of the pictures I've contributed this year. 🪶🦅
December 12, 2024 at 4:17 PM
Happy to say that this year's @batumiraptorcount.bsky.social Autumn Report will be bigger, better and more beautiful than ever. Coming soon.
Making it has inspired me to share more of my #raptor #birdmigration photography here, so a teaser of some of the pictures I've contributed this year. 🪶🦅
Making it has inspired me to share more of my #raptor #birdmigration photography here, so a teaser of some of the pictures I've contributed this year. 🪶🦅
“It’s so bad, even the introverts are here” a sign fittingly said about these unusual protesters — impressive turnout in The Hague today against draconian, short-sighted budget cuts to higher education and research institutes. #WOinActie
nos.nl/l/2545894
nos.nl/l/2545894
November 25, 2024 at 8:37 PM
“It’s so bad, even the introverts are here” a sign fittingly said about these unusual protesters — impressive turnout in The Hague today against draconian, short-sighted budget cuts to higher education and research institutes. #WOinActie
nos.nl/l/2545894
nos.nl/l/2545894
Warmest November 24th on record in the Netherlands. A very comfortable 16°C out, but quite a shock finding both a slow worm and a very recently deceased grass snake this late. Skies devoid of birds, but surprisingly full of insects. November..?
November 24, 2024 at 4:49 PM
Warmest November 24th on record in the Netherlands. A very comfortable 16°C out, but quite a shock finding both a slow worm and a very recently deceased grass snake this late. Skies devoid of birds, but surprisingly full of insects. November..?
Found a clear mistakenly identified/aged/sexed bird? Beer on me at the Green Café this @batumiraptorcount.bsky.social
#BRC16 edition 😉
#BRC16 edition 😉
August 20, 2024 at 3:43 PM
Found a clear mistakenly identified/aged/sexed bird? Beer on me at the Green Café this @batumiraptorcount.bsky.social
#BRC16 edition 😉
#BRC16 edition 😉
As before, I'd be happy to provide people with high-res versions of these photos. Just drop me a line with the Macaulay Library link to the photo(s) and I'll send them to you. I wish eBird would simply let me mark photos as CC BY-NC and enable downloading, but this works too. 🪶
August 20, 2024 at 3:42 PM
As before, I'd be happy to provide people with high-res versions of these photos. Just drop me a line with the Macaulay Library link to the photo(s) and I'll send them to you. I wish eBird would simply let me mark photos as CC BY-NC and enable downloading, but this works too. 🪶
Thanks to massive progress in camera AF systems in recent years, I've focused on getting more ‘unusual’ perspectives of birds: different angles (upperwings!) and environments. With much of migration @batumiraptorcount.bsky.social happening at eye level, it's great to really be able to do this. 🪶
August 20, 2024 at 3:40 PM
Thanks to massive progress in camera AF systems in recent years, I've focused on getting more ‘unusual’ perspectives of birds: different angles (upperwings!) and environments. With much of migration @batumiraptorcount.bsky.social happening at eye level, it's great to really be able to do this. 🪶
Hey #raptor #birdmigration fanatics! Over the past months I've added to eBird what's now almost 3,500 photos of raptors in flight from 4 years at @batumiraptorcount.bsky.social
Most photos are aged/sexed, so you can filter to specific plumages (& more). Enjoy! 🪶
🔗 media.ebird.org/catalog?user...
Most photos are aged/sexed, so you can filter to specific plumages (& more). Enjoy! 🪶
🔗 media.ebird.org/catalog?user...
August 20, 2024 at 3:38 PM
Hey #raptor #birdmigration fanatics! Over the past months I've added to eBird what's now almost 3,500 photos of raptors in flight from 4 years at @batumiraptorcount.bsky.social
Most photos are aged/sexed, so you can filter to specific plumages (& more). Enjoy! 🪶
🔗 media.ebird.org/catalog?user...
Most photos are aged/sexed, so you can filter to specific plumages (& more). Enjoy! 🪶
🔗 media.ebird.org/catalog?user...
Hi all! 👋
Like many, I'm fed up with that other platform and happy to see a thriving community here.
I'm a radar aeroecology PhD candidate at the Uni of Amsterdam, working mostly on birds and wind energy interactions. The image below for a press release out today, summarises it quite well.
🧪
Like many, I'm fed up with that other platform and happy to see a thriving community here.
I'm a radar aeroecology PhD candidate at the Uni of Amsterdam, working mostly on birds and wind energy interactions. The image below for a press release out today, summarises it quite well.
🧪
January 10, 2024 at 1:30 PM
Hi all! 👋
Like many, I'm fed up with that other platform and happy to see a thriving community here.
I'm a radar aeroecology PhD candidate at the Uni of Amsterdam, working mostly on birds and wind energy interactions. The image below for a press release out today, summarises it quite well.
🧪
Like many, I'm fed up with that other platform and happy to see a thriving community here.
I'm a radar aeroecology PhD candidate at the Uni of Amsterdam, working mostly on birds and wind energy interactions. The image below for a press release out today, summarises it quite well.
🧪