Travis Longcore
LightNews LightNews
banner
travislongcore.bsky.social
Travis Longcore
@travislongcore.bsky.social
870 followers 330 following 110 posts

Cities & nature, light pollution, species & landscape conservation, maps & spatial analysis 🌎 Adj. Prof. UCLA Inst. of the Environment and Sustainability

Videos
Environmental science 63%
Geography 16%
Posts Replies Media Videos

Reposted by Travis Longcore

robinheinennl.bsky.social
Robin Heinen @robinheinennl.bsky.social · 14d
Paper 15: Brett Seymoure et al take us to the Chihuahuan desert to test impacts of ALAN shielding types and their resulting impacts on insects. Obviously, all ALAN attracted insects, but shielding, particularly to prevent glare, showed reduced insect attraction. www.sciencedirect.com/science/arti...
Glare more than uplight attracts flying insects to artificial lights
Artificial lighting at night (ALAN) from residential, commercial, transportation, and other sources has substantially altered nocturnal light environm…
www.sciencedirect.com

Reposted by Travis Longcore

robinheinennl.bsky.social
Robin Heinen @robinheinennl.bsky.social · 14d
Paper 13 is out: @travislongcore.bsky.social and colleagues present a detailed framework for ALAN risk assessment for species, using several real-world case studies as examples. Risks have not been taken into account enough in our bright world. Great work!

www.sciencedirect.com/science/arti...
Assessing and mapping taxon-specific effects of ecological light pollution for environmental impact analysis
Predicting the adverse effects of light at night is necessary to ensure compliance with laws and regulations that protect species. Using two case stud…
www.sciencedirect.com

travislongcore.bsky.social
Travis Longcore @travislongcore.bsky.social · 22d
Special thanks to the detailed, patient, and constructive reviewers and the editors of the special issue of Biological Conservation where the study appears. Full issue here: www.sciencedirect.com/special-issu... fin/
Biological Conservation | Artificial Light at Night from a local to global scale: biological impacts and conservation challenges | ScienceDirect.com by Elsevier
Artificial light at night (ALAN) has detrimental impacts on natural systems. Despite growing interest in ecology and a deeper understanding of how light pollution affects different taxa and processes,...
www.sciencedirect.com

travislongcore.bsky.social
Travis Longcore @travislongcore.bsky.social · 22d
Study undertaken at @uclaioes.bsky.social, funded by California Department of Transportation (Caltrans), with collaborators @mherf.bsky.social and Clanton and Associates Lighting Design and Engineering.

travislongcore.bsky.social
Travis Longcore @travislongcore.bsky.social · 22d
Light pollution can be reduced safely, but it requires:
🔬 More spectral response data for wildlife
🖥️ Better integrated software tools
📋 Updated environmental review standards
🤝 Collaboration between lighting engineers + ecologists
It's technically feasible. Let's make it standard practice. 7/

travislongcore.bsky.social
Travis Longcore @travislongcore.bsky.social · 22d
When is light pollution actually "pollution" for wildlife? 🚨
Our proposed thresholds (in animal-adjusted lux):

<0.001: Minimal impact (but glare still matters)
0.01-0.1: Probable significant impacts
0.1: Definite significant impacts

Why? 🌘 Moonlight is ~82% of night hours at <0.01 lux. 6/

travislongcore.bsky.social
Travis Longcore @travislongcore.bsky.social · 22d
We did this analysis with standard lighting software AGi32 + GIS, but it was tedious. The tools exist, but:

Can't handle large areas
Don't talk to each other
Not designed for <0.1 lux precision

We need platforms that combine lighting calculations + ecology + spatial data. Who's building this? 🛠️ 5/

travislongcore.bsky.social
Travis Longcore @travislongcore.bsky.social · 22d
Plot twist: Some shields made things worse. 😬

At one site, house-side shields increased forward light throw, expanding the impact area by 16%.

Lesson: Environmental review needs site-specific analysis. We need better integration of lighting engineering + ecology. 4/

travislongcore.bsky.social
Travis Longcore @travislongcore.bsky.social · 22d
Real-world application: SR-12/SR-113 intersection in CA tiger salamander habitat.

Before mitigation: Light >0.01 lux extended 200+ ft into habitat area.

After shielding + spectral tuning: 38% reduction in area at >0.01 lux. 3/

travislongcore.bsky.social
Travis Longcore @travislongcore.bsky.social · 22d
Why moonlight? 🌒

Animals evolved with lunar cycles. Full moon = ~0.1 lux. But roadway lights can blast habitat with 10-50+ lux.

We developed "moonlight equivalent illuminance"—showing how bright lights appear to each species based on their visual system. 2/

travislongcore.bsky.social
Travis Longcore @travislongcore.bsky.social · 22d
Environmental assessments need to account for spectrum and brightness of light affecting sensitive species. 🌙

We map impact zones using "moonlight equivalent" measures accounting for species visual sensitivity, then apply spectral tuning and shielding.
🔗 www.sciencedirect.com/science/arti... 1/
Assessing and mapping taxon-specific effects of ecological light pollution for environmental impact analysis
Predicting the adverse effects of light at night is necessary to ensure compliance with laws and regulations that protect species. Using two case stud…
www.sciencedirect.com

Reposted by Travis Longcore

mherf.bsky.social
Michael Herf @mherf.bsky.social · 23d
I helped Travis with some moonlight calcs for this paper - our code figures out "how bright compared to moonlight is this light for each species". There is a ton of photometrics and spatial modeling here too:
www.sciencedirect.com/science/arti...
Assessing and mapping taxon-specific effects of ecological light pollution for environmental impact analysis
Predicting the adverse effects of light at night is necessary to ensure compliance with laws and regulations that protect species. Using two case stud…
www.sciencedirect.com

Reposted by Travis Longcore

kylesaunders.bsky.social
Kyle Saunders @kylesaunders.bsky.social · Jan 1
A sympathetic response to Ryan Briggs on trust in social science.
My argument: the deepest problem isn’t error, but epistemic incommensurability-when fields lose shared standards for weighing evidence, experience, and interpretation.
Trust depends on commensuration.
open.substack.com/pub/kylesaun...
Trust, Incommensurability, and the Limits of Intersubjectivity
A response to “Can We Trust Social Science Yet?” by Ryan Briggs
open.substack.com

Reposted by Travis Longcore

macgregorfors.bsky.social
Ian MacGregor-Fors @macgregorfors.bsky.social · Dec 25
📢 NEW SPECIAL ISSUE OUT!

Excited to share a special issue I co-edited on bird–window collisions, a major yet overlooked source of bird mortality

Bringing together 8 papers, this issue advances methods, evidence, and solutions to inform bird-friendly(er) built environments

OA: tinyurl.com/yss5mvf2

Reposted by Travis Longcore

uclaioes.bsky.social
UCLA Environment @uclaioes.bsky.social · Dec 12
A new UCLA–NRDC report shows massive pricing disparities in who pays what for water from the #ColoradoRiverBasin.

Some California urban water agencies shell out over $2,500 per acre-foot of surface water, while some irrigation districts pay $0—for the exact same water. ucla.in/4pC6ODH @nrdc.org

Reposted by Travis Longcore, Tuomas Kankaanpää

ulrikacandolin.bsky.social
Ulrika Candolin @ulrikacandolin.bsky.social · Dec 12
NEW PAPER on impact of #lightpollution, led by Yuhan He who recently defended her PhD thesis.
Historical Exposure to Artificial Light at Night Shapes Daphnia Responses: An Experiment Across an Urban–Rural Gradient - He - 2025 - Ecology and Evolution onlinelibrary.wiley.com/doi/10.1002/...

Reposted by Travis Longcore

ulrikacandolin.bsky.social
Ulrika Candolin @ulrikacandolin.bsky.social · Dec 12
Grateful for received #funding from @koneensaatio.fi for our project on impact of light pollution on the flux of insects between aquatic and terrestrial habitats. Will be looking for a #postdoc and a #PhD for 4 years – take contact if interested.
koneensaatio.fi/apurahat-ja-...
Light pollution – a biodiversity threat: Impact on insect fluxes across ecosystem boundaries - Koneen Säätiö
Insect biodiversity is declining at an alarming rate. Light pollution has been identified as one contributing factor, yet its impact remains poorly known. Aquatic insects with terrestrial life stages ...
koneensaatio.fi

Reposted by Travis Longcore

uclasustainablela.bsky.social
Sustainable LA @ UCLA @uclasustainablela.bsky.social · Dec 4
Join us for Policymaking Under Uncertainty: Zone 0 and Vegetation Management on Friday December 12, 2025 at 12 p.m. PT
👉 Register today: ucla.zoom.us/webinar/regi...

@edithdeguzman.bsky.social | @travislongcore.bsky.social | Max Moritz | Alessandro Ossola | Nurit Katz
Policymaking Under Uncertainty: Zone 0 and Vegetation Clearance webinar announcement, Friday December 12, 2025 at 12PM PT. Panelists: Edith de Guzman, Travis Longcore, Max Moritz and Alessandro Ossola. Moderated by Nurit Katz and hosted by the UCLA Sustainable LA Grand Challenge.

Reposted by Travis Longcore

Reposted by Travis Longcore

uclalawemmett.bsky.social
UCLA Emmett Institute @uclalawemmett.bsky.social · Nov 24
Read our suggestions for how to kickstart the important transformation of our urban environment to help shield residents from the worst effects of rising temperatures @uclaioes.bsky.social @law.ucla.edu @uclasustainablela.bsky.social @luskininnovation.bsky.social

law.ucla.edu/news/reducin...
A woman using an umbrella to shield the sun on a park bench

travislongcore.bsky.social
Travis Longcore @travislongcore.bsky.social · Nov 19
You don't say. Quality of news outlets shared is lower on conservative social platforms. Bluesky --> more liberal and higher quality news outlets shared. PNAS paper: www.pnas.org/doi/10.1073/... Since you nerds asked, news outlet quality rankings from this paper: academic.oup.com/pnasnexus/ar...

travislongcore.bsky.social
Travis Longcore @travislongcore.bsky.social · Nov 14
Looks like a well-conceived and very necessary initiative; count me in!

travislongcore.bsky.social
Travis Longcore @travislongcore.bsky.social · Nov 14
Media picked up our latest extreme heat work and writes better headlines than I do.. www.yahoo.com/news/article... #urbanecology #extremeheat #parks
Researchers make surprising discovery while studying people's behavior at public parks: 'One compelling exception'
They conducted the research using smartphone location data.
www.yahoo.com

Reposted by Patrick A. Jansen, Travis Longcore

dmevans.bsky.social
Darren Evans @dmevans.bsky.social · Nov 13
If you are interested in helping us to mitigate the impacts of light pollution #ALAN on biodiversity, and work on street lighting mitigation and road safety, consider joining our Knowledge Network: www.ncl.ac.uk/press/articl...
Lighting the way to safer, smarter and sustainable roads
A new European research initiative, SAFELUX – The Light We Need, is set to transform how we light our roads at night - improving safety while reducing energy use and environmental impacts.
www.ncl.ac.uk

Reposted by Travis Longcore

Reposted by Travis Longcore

travislongcore.bsky.social
Travis Longcore @travislongcore.bsky.social · Nov 6
My projects have always done all-sky measurements under all conditions because I'm concerned with the effects on wildlife, as well as interested in seeing the stars. For example, this paper --> iopscience.iop.org/article/10.1... where we show the influence of the % clouds on illuminance.
Radware Bot Manager Captcha
To ensure we keep this website safe, please can you confirm you are a human by ticking the box below.
iopscience.iop.org

Reposted by Travis Longcore

ricardonature.bsky.social
Ricardo Rocha @ricardonature.bsky.social · Nov 3
In 2010-2013, conservation teams on #Chichijima - 1 of the main islands in the #Ogasawara chain - captured & removed 131 feral cats. The goal was to reduce predation pressure on an endangered pigeon. The results were immediate: adult pigeon numbers rose from 111 to 966 www.nature.com/articles/s42...

Reposted by Travis Longcore, Peter Jacobs

cira-csu.bsky.social
cira-csu.bsky.social @cira-csu.bsky.social · Oct 30
A look at the devastating power loss across Jamaica following the historic crossing of Hurricane Melissa, captured by NOAA-21.