Eric R. Larson

CLIMEX Match Climate Composite Match Index (CMI) overlaid with Tipuana tipu distribution location records, projected globally. Insets show the native range, part of South America, part of southern Africa, southwest Australia, and an area of eastern Australia with high levels of cultivation and/or naturalisation. Areas with an orange-red colour (CMI 0.8–1) had high CMI values. Areas with a blue colour (CMI 0.6–0.8) had a climate with moderate CMI values. Records of T. tipu are shown as open circles. Pink circles represent records of plants within the native range. All other colours represent plant records in the non-native range, with purple representing cultivated plant records, yellow representing non-cultivated plant records, green representing records with both cultivated and non-cultivated plants and brown representing plant records where the cultivation status was indeterminate.

The interplay between climatic niche and spatial distribution can inform the management of non-native invasive species. Our findings reveal that the invasion risk for species with small geographic ranges may be greater than assumed.
Read more (OA): doi.org/10.1016/j.ec...
#bioinvasions 🌐🌏🧪

Love rivers?! Looking for an exciting PhD opportunity to better understand how to restore rivers at a landscape scale with multiple stakeholders?!
Details below!
@stir.ac.uk

www.findaphd.com/phds/project...

Apologies on the overly literal reply. If I had to do a filibuster, I would probably fill the first 3 hours on the Idaho/Boise State rivalry - I don't get many chances at it!

Well, Moscow (University of Idaho) is a shorter drive to Seattle than to Boise and about 11 hours from Salt Lake City. Northern Idaho is more Pacific Northwest than Great Basin. Idaho's campus is also ~8 miles from Washington State University.

Idaho versus Boise State football series results from Wikipedia at https://en.wikipedia.org/wiki/Boise_State%E2%80%93Idaho_football_rivalry

Sort of? But it was always a series of streaks: Idaho won 12 straight into the 90s, and then Boise State dominated (12 straight) after both moved up to D-1A. But the overall series stands at 22-17-1. I think the streakiness contributes to the nastiness - Vandals expected to win but the world change.

"The disc is here, I need to watch it" was a better motivator for me than "It's on my saved list, I'll get around to it." It was physically carried to me by multiple people. I have to return it. Watch the movie.

Meet The Mazama Newt. And The People Fighting To Save It. YouTube video by Oregon Zoo

Happy Newt Year!

youtu.be/YkFhMYGAdCY?...

When I collected Okanagan Crayfish there in 2010, crayfish were hard to come by - a few individuals per multiple hours of diving nearshore. Abundances were higher in smaller lakes. Large Signal Crayfish active on the lake bed would really stand out, but it's of course a big lake. (2/2)

Yeah, I wonder about the status of these observations over the past five years - no obvious Signal Crayfish at Okanagan Lake on iNaturalist (only one nearby) but the divers of course may not be iNat users. Have people kept encountering big Signal Crayfish in the lake? (1/2)

Well, I shouldn't steal Caitlin's thunder, as the paper is in review. But it was interesting to compare across the many museum collections. A Procambarus zonangulus specimen did make our list of 20 largest crayfish documented in North America.

I fell short by ~10 mm CL to the two Bottlebrush species. But that 75 mm CL Signal looked like a lobster, and I would have guessed it was much larger than its measurement when I first saw it. (2/2)

Ah, 2020 - I missed the date. On 12 inch crayfish: Caitlin Bloomer is leading a paper on North America's biggest museum vouchered crayfish. I was confident I had the winner as a Signal at the Royal BC Museum, but (1/2)

I mean, there's a video here, but there's no scale to the video like the diver's hand or similar. The largest Signal Crayfish on record (~75 to 78 mm CL) look absolutely enormous in person, but 12 inches TL is crazy. It would be a record for both the Astacidae and Cambaridae to my knowledge.

... a diver seeing a big crayfish and not catching or measuring it is about as exciting a news story to me as someone claiming they saw Ogopogo. It's a fish story; get a specimen in-hand or it's nothing. (2/2)

Yeah, it's not clear to me from the article that anyone involved is aware of the Okanagan Crayfish as a species distinct to the Signal Crayfish or is just referring to Signal Crayfish in Lake Okanagan as Okanagan Signal Crayfish informally. But ... (1/2)

By the article, though, that isn't the crayfish claimed at 12 inches, which was seen by a diver but seemingly not collected. It's just an example of a recent big crayfish found dead in the lake (per the image caption). It would, however, be consistent with ~largest Signal at the Royal BC Museum

Last, on "put the ID of Okanagan vs Signal crays into some doubt" - I'm not sure how? We provide guidance on ID between the two species by morphometrics in the Zootaxa paper, and sequencing is cheap. The answer to whether they are Okanagan or Signal crayfish is an mtDNA barcode away. 6/6

Aschhoff said he's completed around 2,000 dives in various areas of Okanagan Lake over the last 14 years and has never seen a crayfish before. As the crustacean tend to live in rocky areas, they are usually found closer to shore.

At the news article, I'd worry about this quote. Extremely large crayfish at depth in the lake are a recent observation? Then that may be a new Signal Crayfish invasion, particularly as our Okanagan Crayfish specimens at the Royal BC Museum are generally smaller than Signals. 5/n

Because of their size, people stock Signal Crayfish for harvest (or sometimes as fish forage), including widely within western North America at Vancouver Island, Crater Lake, Lake Tahoe, southern Idaho (peerj.com/articles/5668/). I think many Signal populations are introduced. 4/n

Genome skimming supports two new crayfish species from the genus Pacifastacus Bott, 1950 (Decapoda: Astacidae) | Zootaxa

The Zootaxa paper spends both intro and discussion text on the risk of stocking Signal Crayfish over congeners, attributed, for example, as a cause of extinction and ESA listing for Pacifastacus species in California (www.mapress.com/zt/article/v...). 3/n

The signal crayfish is not a single species: cryptic diversity and invasions in the Pacific Northwest range of Pacifastacus leniusculus 1. We used historical sources, morphology-based taxonomy and mtDNA sequence data to address questions about the signal crayfish Pacifastacus leniusculus. These included evaluating unrecognised crypti...

I do not interpret Signal Crayfish as native to BC; they were introduced at the coast (doi.org/10.1111/j.13...), and I think the globally invasive Signal Crayfish was moved east of the Cascade Mountains, consistent w/Susie Adams' work in MT (doi.org/10.1002/wat2...). 2/n

I would say: I never collected Okanagan and Signal Crayfish in sympatry, from e.g. the same lake, including Lake Okanagan. I am aware of Signal Crayfish in the vicinity of Okanagan Crayfish, and include one of those populations (Loon Lake, WA) in the Zootaxa paper. 1/n

Looks like signal, I don't doubt they're around (certainly in the Columbia in WA & BC). Can't judge size from the image w/out scale. The largest crayfish of any species in any museum in North America is 86.6 mm carapace length (~7 inches total length); a specimen in hand would be interesting.

Three stream sites as columns over five sampling events as rows from fall (top) through mid-winter (bottom), taken from bridge crossings looking upstream. The stream in the left column is adjoined primarily by row crop fields with a wood lot in the distance. The stream in the middle column has an intact riparian buffer with leaves changing color at the top rows through absent in the bottom rows. The stream in the right column is the largest and is neighbored by dense riparian forest with a ridgeline visible in the middle distance.

This is another of our studies that I really value for getting us out to the same streams throughout the year, with a snapshot here of a few of our fall and winter sampling events.

Linear mixed model predictions for aquatic (blue solid) and terrestrial taxa richness (brown dotted) in response to (A) rainfall (in centimeters) and (B) water temperature (in degrees Celsius) with 95% CIs.

Do precipitation events have opposing effects on aquatic versus terrestrial environmental DNA (eDNA) recovered from streams and rivers? New from the lab at Ecological Applications: doi.org/10.1002/eap....

This is a little reassuring as an Illinois fan.

Image of river protection status in the United States

National assessment of river protection in the U.S.

Article: doi.org/10.1038/s418...
Policy Brief: doi.org/10.1038/s418...
Rivers Explorer: map.myriver.americanrivers.org

Collaboration b/t American Rivers, Conservation Science Partners, Univ WA @americanrivers.bsky.social

Thread 👇 | DM for PDF

Tarantula with XXL genitalia, 'death ball' sponge among cool species of 2025 | CBC News A spider with extraordinary genitalia, a carnivorous caterpillar that wears its prey's body parts, and a tiny opossum are among the cool new species described by science in 2025.

Excited that our newly described Okanagan Crayfish makes an appearance on the CBC's cool species of 2025 list: www.cbc.ca/news/science...

A black and white image of a signal crayfish (Pacifastacus leniusculus) seen from the side or lateral view with barnacles covering ~50% of its carapace.

Semi-related: this signal crayfish from G.C. Miller's 1960s thesis (The Taxonomy and Certain Biological Aspects of the Crayfish of Oregon and Washington), covered in barnacles out of the Columbia River estuary at Astoria.

bro you gotta molt