Tohar Tal
LightNews LightNews
banner
tohar-tal.bsky.social
Tohar Tal
@tohar-tal.bsky.social
830 followers 740 following 37 posts
Birding | Ornithology | Migration & movement ecology | Conservation | Chairman @batumiraptorcount.org | Human-wildlife conflict | Policy Researcher @ FBE Noord-Holland | Graduated MSc Ecology @ IBED UvA |

📸 ➡️ flickr.com/photos/135764186@N07/
Posts Replies Media Videos
Pinned
tohar-tal.bsky.social
Tohar Tal @tohar-tal.bsky.social · Nov 19
📢 NEW STUDY describing the first full-season spring raptor migration counts in the eastern Black Sea flyway!
Read about seasonal contrasts in raptor migration, the eastern Black Sea coast as a principal spring flyway, and more.

Preprint ➡️ biorxiv.org/content/10.1...

1/9🧵👇
Black Kites in front of the Batumi skyline. One of the most abundant species at Batumi in spring.
Reposted by Tohar Tal
kyle-horton.bsky.social
Take three minutes to look at pretty birds, explore radar data, and see how we connect the structure of skies to MacArthur's ideas of niche partitioning. 📡🐦☁️🎧
November 20, 2025 at 6:28 PM
Reposted by Tohar Tal
batumiraptorcount.org
A typical Batumi migration scene, illustrating the idea of an ‘aerial niche’. For Steppe Buzzards in our bottleneck, that niche is often somewhere between the clouds: great to watch, tricky to count.

Fascinating paper by @cnilsson.science et al: doi.org/10.1016/j.tr...

📸 @barthoekstra.bsky.social
cp-trendsecolevo.bsky.social Trends in Ecology & Evolution @cp-trendsecolevo.bsky.social · 15d
November issue out online now
www.cell.com/ecology-evol...

We hope you enjoy it!

The cover article is by Cecilia Nilsson and colleagues, photo by Bart Hoekstra

The penultimate interviews in our Disability series feature John Dennehy and Tara Cronin
November 18, 2025 at 8:41 PM
Reposted by Tohar Tal
hadley.nz
filter_out() = yeet()
davisvaughan.bsky.social Davis Vaughan @davisvaughan.bsky.social · 20d
We are looking for #rstats community feedback on 3 new dplyr functions!

We're aiming to expand the `filter()` family:

- `filter()` to keep rows
- `filter_out()` to drop rows
- `when_any()` and `when_all()` as modifiers

Read more and leave feedback here:
github.com/tidyverse/ti...
Example of using `filter_out()` on the `penguins` dataset, showing how it is much easier than `filter()`, especially with `NA`s
November 7, 2025 at 4:34 PM
Reposted by Tohar Tal
bou.org.uk
Dispersal, maturation and recruitment in a long-lived, intercontinental migrant bird | www.sciencedirect.co... | Animal Behaviour | #ornithology 🪶
October 28, 2025 at 3:34 PM
Reposted by Tohar Tal
barthoekstra.bsky.social
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... 🧪🪶
Fig. 2. Maps of nocturnal bird migration across the Netherlands in spring and autumn, with the 100 km radius circles of the weather radars enclosing the onshore study area. Colors represent seasonal migration passage, converted from the original bird densities. Shaded areas mark grid cells for which over 25% of the input data, prior to filtering, were impacted by ground clutter. Migration passage in these regions may be compromised in either direction: overestimated due to remaining clutter artifacts or underestimated where terrain features partially obstruct the radar’s lower scanning angles. Fig. 1. Flight altitude distributions (in m above sea level (asl)) of nocturnal bird migration for both Dutch weather radars at a coastal Den Helder and inland site Herwijnen. Bar length denotes the proportion of migration within the respective altitude range (50 m vertical resolution). Donut charts aggregate this further to coarser 200-m classes and display the proportion of migration occurring above 1000 m (patterned). Red highlights indicate the altitude range of onshore energy infrastructure in the Netherlands, which is generally present in the lowest 200 m of the atmosphere. Donut chart proportions do not sum to 100% due to rounding. The small inset map of the Netherlands shows the locations of both radars (solid dots) and the surrounding areas up to 35 km (circles) from which altitude distributions are aggregated. Fig. 3. a, c Observed combinations of migration passage and mean wind power density, a measure of wind power potential, in North-Holland. Red circles represent average values for candidate sites and their size reflects the relative candidate site area. The grid reflects binned values of migration and wind power density, with color shading indicating the type of combination: orange = high migration passage, blue = high wind power density, dark browns and blues = both high. White lines indicate averages for wind power density and seasonal migration passage. b Spatial distribution of autumn migration (orange hues) and wind energy (blue hues) in North-Holland. Candidate wind energy sites are shown in bright red. The highest and lowest autumn migration passage sites are linked to their positions in a and c, emphasizing large differences between sites in autumn, but not in spring. Shaded areas mark grid cells for which over 25% of the input data, prior to filtering, were impacted by ground clutter. Migration passage in these regions may be compromised in either direction: overestimated due to remaining clutter artifacts or underestimated where terrain features partially obstruct the radar’s lower scanning angles.
October 30, 2025 at 12:58 PM
Reposted by Tohar Tal
rosemarymosco.com
Halloween costume ideas for birders.
A comic called halloween costume ideas for birders. In panel 1, labeled easy, there's a person labeled northern cardinal wearing a party hat, a beak, and red clothes, and a person labeled roseate spoonbill wearing pink clothes and a wooden spoon on their nose. In panel 2, labeled harder, there's a person labeled merlin sound ID wearing a big green circle with a microphone modeled after the button on the merlin sound ID app, and a person labeled hybrid green x blue jay wearing a complex costume with a mask and robe and hat modeled after a recently discovered hybrid bird. In panel 3, labeled challenging, there's a person labeled baltimore oriole nest wearing an enormous accurate woven oriole nest suspended from their arms and shoulders, and a person labeled african jacana carrying chicks with a hideous costume of long-toed bird feet hanging from their armpits. In panel 4, labeled hot, there's a person labeled high quality spotting scope who is shirtless and is wearing a spotting scope mask on their head, and a person labeled sexy owl pellet wearing an owl pellet top and bottom with a mouse skull on their head.
October 23, 2025 at 12:26 PM
Reposted by Tohar Tal
batumiraptorcount.org
It’s a wrap! 🎉

Today marked the final day of #BRC17! What an unforgettable season it’s been: records broken with countless surprises and memories made. All the details will be included in our upcoming autumn report, which will be released soon.

Keep an eye on our social media to stay up-to-date.
Station 1 team today. Station 2 team today. The last bird of the season? Thas was a Steppe Buzzard of course! Photo by Bart Hoekstra. The final season total!
October 21, 2025 at 1:51 PM
Reposted by Tohar Tal
batumiraptorcount.org
1.5 MILLION RAPTORS! 🦅🤯

For the first time in BRC history, we have recorded a staggering 1.5 million raptors in a single autumn season — a true milestone after 17 years of counting!

Read more here: www.batumiraptorcount.org/brc17/2025/10/15-million-raptors

#ornithology #RaptorResearch
Steppe Buzzards moving through the cloudy Batumi bottleneck. Photo by Tohar Tal. The Station 1 team. The Station 2 team. The team of coordinators at station 3 — for a change.
October 20, 2025 at 2:43 PM
Reposted by Tohar Tal
theguardian.com
Bird migration is changing. What does this reveal about our planet? – visualised
Bird migration is changing. What does this reveal about our planet? – visualised
Bird migrations rank as one of nature’s greatest spectacles. Thanks to GPS tracking, scientists are uncovering extraordinary insights into ancient and mysterious journeys – and new threats that are reshaping them.
www.theguardian.com
October 16, 2025 at 8:32 AM
Reposted by Tohar Tal
jengill.bsky.social
The latest wadertales blog (no. 151) describes how scoring moult from photographs can reveal moult season duration and how it varies between populations: wadertales.wordpress.com/2025/10/09/m...
#ornithology
October 9, 2025 at 12:16 PM
Reposted by Tohar Tal
batumiraptorcount.org
Live from the field!

The 1,422,172nd bird — a juvenile Black Kite flying through the misty clouds — crossed our transect line this afternoon, making 2025 the BIGGEST year in BRC history!!

Stay tuned for more!
Team at station 1 Team at station 2 Black Kite making it's way through the mist - though views, yet so rewarding! Photo by Bart Hoekstra.
October 5, 2025 at 11:54 AM
Reposted by Tohar Tal
pauldufour80.bsky.social
🚨 Master’s project!
Curious how birds find their way? 🧭🐦
Analyze decades of ringing data to study abnormal migratory routes and uncover what these deviations can reveal about the mechanisms guiding birds on their journeys. Drop me an email for details! #ornithology

www.vogelwarte.ch/de/wir/mitar...
October 3, 2025 at 7:11 AM
Reposted by Tohar Tal
jasondovemark.bsky.social
If conservationists work from a compromised baseline, our notions of abundance, scarcity, and ecological wellbeing will keep getting defined downward:
"The researchers show that using the 1970s as a baseline tends to normalize an already severely degraded state."
phys.org/news/2025-10...
Bird conservation threatened by shifting baseline syndrome
New research shows that populations of dozens of waterbird and seabird species have been declining for much longer than previously thought in Europe. The article "Shifting the baseline for waterbird a...
phys.org
October 2, 2025 at 5:03 PM
Reposted by Tohar Tal
batumiraptorcount.org
170.000 RAPTORS IN ONE DAY!

After yesterday’s heavy rain and a quiet morning, today the sky exploded with Steppe Buzzards and large eagles! Continuing from 10 am until almost the end of the count.

At some point, we counted over 14.000 raptors in less than 20 minutes. THAT'S BATUMI!

#ornithology
Today's totals! See our website for more details! Steppe Buzzards. Photo by Filiep T'jollyn After-count team photo - with perhaps the most beautiful rainbow ever seen in the background
October 1, 2025 at 6:17 PM
Reposted by Tohar Tal
batumiraptorcount.org
After the thrill of reaching the million, we went straight to the peak of diversity. The challenge of counting high numbers of birds slowly shifted into identifying the (relatively) fewer but more difficult ones: the large eagle species!

But they also brought a special guest along...👇

1/2
Lesser Spotted Eagle - Photo by Eduardo Campos Wals Lesser Spotted Eagle - Photo by Matthew Sprangers Black Kite (left) and Steppe Eagle (right) - Photo by Matthew Sprangers Lesser Spotted Eagle - Photo by Filiep T'jollyn
September 29, 2025 at 3:17 PM
Reposted by Tohar Tal
cataranea.bsky.social
I love the way science used to be written. Is it necessary to know that the author was pushing his baby in a pram while making observations of insects? Perhaps not, but it provides delightful context, while assuming the reader is familiar with his previously published baby-wheeling-related work.
A screenshot of some text of a paper, with the following sentence highlighted: "One July evening last summer, while engaged in wheeling the baby (another one this time) through some tall grass in the corner of my yard, I noticed..." It continues "an Ammophila attached to a grass-stem in the peculiar..."
September 26, 2025 at 1:24 PM
Reposted by Tohar Tal
migecol.bsky.social
NEW PUBLICATION on stopover ecology of Songbirds during spring migration: After packmor et al. 2020 (Mov Ecol) found that trans-Saharan migrants react differently to weather for migratory departure, we aked ourselves, whether this is also valid for spring migration? 🐦
a thread 🧵 on 7 hypotheses:
the 5 study species: Dunnock, Northern Wheatear, European Robin, Common Redstart, Garden Warbler
September 26, 2025 at 8:02 AM
Reposted by Tohar Tal
wmgvs.bsky.social
A dramatic end for an ambitious Spoonbill. Yday morning LAYLA crashed into the ocean just offshore Madeira, 56h after departing from the Wadden Sea. She rested barely 7h even though she found nice Spoonbill hotspots on the way. Poor choices... #ornithology
www.globalflywaynetwork.org/tracks/speci...
September 25, 2025 at 8:02 AM
Reposted by Tohar Tal
batumiraptorcount.org
A true Bluesky — filled with raptors!

After days of rain, we were greeted by a bright, blue, cloudless sky this morning! The result? Thousands of birds and a high species diversity.

With the main message: the eagles are coming!

Stay tuned for more! For daily totals: www.batumiraptorcount.org/data
Marsh Harrier. Photo by Nikolina Bukovac Short-toed Eagle and Black Kite. Photo by Nikolina Bukovac. Greater Spotted Eagle. Photo by Nikolina Bukovac. Where are the birds? Somewhere up there in the blue sky!
September 22, 2025 at 6:35 PM
Reposted by Tohar Tal
wmgvs.bsky.social
The www.BirdEyes.org team is thrilled to announce a new paper by Mohamed Henriques showing how Spoonbills change space use over the course of their summer stay in the eastern Dutch Wadden Sea. After breeding, many adults converge in the Lutjewad area. #ornithology

www.birdeyes.org/lutjewad-amo...
September 22, 2025 at 9:51 AM
Reposted by Tohar Tal
cnilsson.science
Are animals randomly distributed in the air, or is there a structure to where and when we find them? In our new paper we outline factors that shape habitat use in the air, from abiotic structure to biotic interactions. A lot of fun discussions behind this one! 🦅🦋🦇🌬
www.cell.com/trends/ecolo...
Animal niches in the airspace
For flying animals, including many birds, bats, and insects, the air is a crucial arena for a range of behaviors. Technological advances, such as year-round tracking of flight altitudes and expanded u...
www.cell.com
September 22, 2025 at 8:04 AM
Reposted by Tohar Tal
batumiraptorcount.org
This achievement was only possible thanks to our amazing and hard-working team – counters, trainees, coordinators – and our wonderful host families for their endless hospitality.

Check out our daily counts and news flashes here: www.batumiraptorcount.org/data

2/2
September 17, 2025 at 3:18 PM
tohar-tal.bsky.social
Here we go!!
batumiraptorcount.org Batumi Raptor Count @batumiraptorcount.org · Sep 17
ONE MILLION RAPTORS!

The wait is over... Today #BRC17 hit the earliest 1-million mark in BRC history! Usually, this happens around end-September, but this year the raptors clearly had other plans.

And with still over a month to go, we expect plenty more to come!

1/2
#ornithology #RaptorResearch
One of many kettles of Black Kites we've counted over the past days. Photo by Sander Bruylants. A crisp juvenile Lesser Spotted Eagle in beautiful light. Photo by Sander Bruylants. Screenshot of our live seasonal raptor 'counter' on the website.
September 17, 2025 at 3:20 PM
Reposted by Tohar Tal
wpmueller.bsky.social
#ornithology
www.nature.com/articles/s41...
Direct mortality due to humans threatens migratory shorebirds - Nature Ecology & Evolution
Direct human actions such as hunting and bird deterrence at aquaculture sites kill up to 10% of the populations of some shorebird species migrating along China’s coast each year, suggesting that this ...
www.nature.com
September 13, 2025 at 10:26 PM
Reposted by Tohar Tal
naturetodaynl.bsky.social
Trekvogels versnellen naar de Noordpool, maar de klok tikt door
Door klimaatverandering begint de lente in het noordpoolgebied steeds eerder in het jaar. Trekvogels staan onder druk: ze moeten hun voorjaarsmigratie naar het noorden versnellen om te voorkomen dat ze te laat aankomen op hun broedplaatsen. Hun aanpassingsvermogen is indrukwekkend, maar het versnellen van de trek heeft een natuurlijke grens, waarschuwen onderzoekers.
dlvr.it
September 10, 2025 at 5:01 AM