Date: 10/6/25 8:47 am From: Ian McDonald (via carolinabirds Mailing List) <carolinabirds...> Subject: Re: thermal monocular
Glad this subject has come up. Thermal has been a tool I’ve used religiously for the past couple years.
Last year, Janelle and I did a big year and I would estimate that we used thermal to locate (not id) ~50 of the 350 species we saw last year. It has been an absolute game changer for us. You’d be shocked on the number of birds you miss. It has opened a whole new realm of birding for us.
I use the thermal just about any time we go birding (regardless of the weather conditions). I have a Pulsar Merger LRF XL50 Thermal Binocular (predecessor to the LRF XT50). It has an extremely sharp HD sensor with 1024x768 resolution with ability to take photos, stream and record videos. It performs well under almost any weather condition.
Recently, our hawk watch conditions were terrible (bright blue sky with no clouds), simply looking up with it, I was able to spot streaming Broad-winged hawks that others were able to confirm with their bins. It was even great spotting kettles. If you are on Facebook, join the Riverbend Hawk Watch and I’ve posted some of the photos/videos.
Whenever a bird is at Hooper Ln., it takes only a minute or so to scan the sod farms to locate the rare plovers and sandpipers. Snowy Plover at Cape Point, LeConte’s sparrow at B. Everett Jordan Lake Dam, Black Rail and American Barn Owl at Bodie Island, Short-eared owls at Alligator River, all were instances where I’m sure we would not have found the bird without the assistance of thermal. Thermal even worked well at Jeanette’s Pier and on pelagic trips regardless of the time of year (but made me sick).
I’ve used the thermal at night to watch migrating birds, and have seen hundreds. However, I could not identify a single one as I’m not versed with nocturnal flight calls…yet
As mentioned previously, there is a learning curve to distinguish the heat signatures. If you are prone to motion sickness, I would recommend trying it out first before buying, as these are not cheap.
We love sharing our technology, if anyone would like us to join upcoming CBCs to help find birds that are normally impossible to spot, please reach out to us. If you see a guy lugging a big lens and two sets of binoculars, and want to see the thermal, I’d be happy to show you.
Happy Birding!!
Ian R. McDonald
Cell: 8283020554
From: <carolinabirds-request...> <carolinabirds-request...> on behalf of Michael Fogleman <carolinabirds...>
Date: Sunday, October 5, 2025 at 1:14 PM
To: Trevor Sleight <sleightphoto...>
Cc: Derb Carter <dcarter...>, carolinabirds listserve <carolinabirds...>
Subject: Re: thermal monocular
I have a Pulsar Telos XP50. It ain't cheap but it works great. It has a 640x480 pixel sensor with a 50 Hz refresh rate. It can supposedly resolve temperature differences down to 0.015 degrees Celsius. The battery life is fantastic, it can last ~8 hours on a single charge. It's weather proof and generally very robust construction and feels good in the hand. It can take pictures and record videos. It has a mobile app that can show you what the scope sees and control it.
I used it to find those Chuck-will's-widows earlier this year. No way I would have found them with the monocular.
If you know of a screech owl nest cavity in the breeding season, you can usually pretty easily find the male roosting nearby using the monocular.
Speaking of cavities, you can usually tell if one is occupied or not due to the heat.
Sleeping raccoons are a common find.
I found a very young fawn bedded down really close to where I was standing. Completely invisible to me without the monocular.
I've had many "accidental" finds while looking for other things. A black & white warbler nest, a white-eyed vireo nest, a chickadee nest in a cavity, a very young fledgling sitting dead still in the bushes, etc.
The scope works best on fully cloudy days, or just after a rain, or at night. If it's cloudy or rainy, most of the landscape is at an even temperature, so then the animals really pop out. If it's sunny, everything is at uneven temperatures and nothing stands out anymore. This is significant - if it's sunny out I won't usually bother with it at all.
As far as how you go about using it, you can just carry it around and inspect things that you think might be interesting (like tree cavities) or you can sweep large areas looking for whatever. It's a fairly narrow field of view but that's good if you hope to find small heat sources that aren't very close up.
Michael Fogleman
Cary, NC
On Sun, Oct 5, 2025 at 12:05 PM Trevor Sleight <carolinabirds...><mailto:<carolinabirds...>> wrote:
Hi Derb/ list serve,
I’d recommend searching for episodes of “Naturally adventurous” and “Life List: A birding podcast”that discuss thermals. Neither goes into the technical side of things but both are informative. One important takeaway is that thermal birding is its own pace and style of birding that requires an adjustment just like someone birding with the intention of taking photos birds differently than someone with just bins. I’d also recommend the two podcasts in general in addition to better known ABA podcast by Nate Swick.
S4E28: Thermal Imaging Devices as a Natural History Game-Changer
Naturally Adventurous
Feb 11, 2024 • 49 min
Comparing thermal scopes, Hurricane Helene effects, and the beauty in the unknowns on pelagics
Life List: A Birding Podcast
Sep 30, 2024 • 1hr, 5 min
Happy birding,
Trevor Sleight
On Oct 5, 2025, at 11:41, Derb Carter <carolinabirds...><mailto:<carolinabirds...>> wrote:
I read in trip reports that birders are increasingly using thermal monoculars for nocturnal birds and mammals. Interested if you have experience with these devices for this use and any recommendations.
