2023-10-22T20:52:49UTC

Random bits of week 42, 2023

oneliner TILs

• Carrington Event (1859) was the strongest solar storm in recorded history. It created auroras so bright that US gold miners thought it was morning, got up and began preparing breakfast. Telegraph systems failed in Europe and North America due to geomagnetically induced current, but there's also this case where two operators in Boston and Portland, respectively, was able communicate without power supplies on either end. (See wikipedia references.) Wikipedia of course has a list of solar storms.

• Found digital archive of Whole Earth Index, a series of journals and magazines. Almost like a physical wikipedia rabbit hole run, with reference links as amazon one-click buys (but an actually good catalog).

• River by Max Bittker and Are.na is like google image find-visually-similar but more explorative, based on CLIP and pgvector. As the site has indicated, it is an image browser for fun and not for searching. I would enjoy a search engine out of this stack, though. There is also a similar work Same Energy, which does NOT use CLIP but their own method (unspecified).

Orcas are not a common predator of moose, but moose do dive quite deep for food

This tumblr post^[1] from Aug 1st, 2019 said:

Just found out moose can dive as deep as 20 feet (6m) for aquatic vegetation. Can you imagine like, being a diver, and you’re 20 feet underwater, it’s murky, and you run into a moose. A MOOSE!!!!

According to this twitter thread from Feb 2021 by Emma Luck, the tumblr post and one of its comments resulted in a comic strip posted to boredpanda in Oct 2019 that tells a myth of orcas regularly predating on diving moose. In the thread, Emma found only one documented case of any orca attacking moose:

Two fishermen reported seeing a small group of killer whales attack a pair of moose that were crossing a channel in Icy Strait [, southeast Alaska, 1993]. They killed one moose, and the second moose escaped but later drowned in a kelp bed. This is referenced in the book "Transients: Mammal-Hunting Killer Whales of British Columbia, Washington, and Southeastern Alaska" by John Ford and Graeme Ellis.

While the thread also mentioned that orcas' diet are "influenced largely by their culture" therefore it is not impossible that there were more such cases, Emma concluded that moose are unlikely to be a common prey. Emma studied marine biology at the University of Alaska Southeast in Juneau, Alaska (ref) and studied/is studying marine policy as a grad student (via their twitter profile). This page from earthtouchnews.com referred to the same book, but instead mentioned a case happened in Jackson Bay on the centrl coast, 1961, and another anecdote from 2010 "according to [...] Marilyn Dahlheim" (which unforunately was not linked to any original writings of Dahlheim, and searching Marilyn Dahleim deer on google let the earthtouchnews.com page to be the 1st result. FML).

On the other hand, moose are known to wade into water and feed on aquatic plants. For example, in this a 1 minute video on youtube from Science the journal reposting Bump et al. 2016, OIKOS ^[2], moose feeds underwater with ease, with its shoulder submerged but not too deep under the water surface. They swim well, for example see this video. On the other hand, i couldn't find any video of moose diving deep. The tumblr post in question attached several photos, but none effectively demonstrates the water depth.

Based on google and tineye reverse image searches, there appear to be no earlier sources of the tumblr posts's photos, which gives us more confident about OP's story. Wikipedia has one sentence that cited Peterson, Randolph L. (1955). North American Moose. Toronto: University of Toronto. ISBN 0802070213 in support of moose diving.

The book should be quite reliable given its detailed writing and the chain of trust: Peterson was an/the Acting Curator of the Royal Ontario Museum when he enrolled in a PhD program and did field work in Algonquin Park studying moose (source: obituary of Peterson by Journal of Mammalogy) in 1946 summer. Journal of Mammalogy describes the book as "an authoritative study of the species", and the book's foreword was written by W.J.K. Harkness, who was then a faculty member at University of Toronto and Director of the Ontario Fisheries Research Laboratory && its station site at Lake Opeongo (ref). The book is available on archive.org via digital borrow. I checked up on libgen's version (2018 reprint?) out of laziness. On page 108 it wrote:

Water is definitely one of the preferred elements in the habitat of moose. When feeding on submerged aquatic vegetation they occasionally dive for plants in water over 18 feet deep. They were frequently seen to submerge so completely that not a ripple remained in the water near where they went down.

And on page 119,

In the shallow waters of Algonquin Provincial Park [, Ontario], moose were not forced to dive to reach ample food. In early spring most animals merely submerged their heads to feed on the young growing plants. By midsummer we noticed that moose rarely reached deeper than about 12 inches, with most animals feeding directly from the surface on floating leaves and stems. In the St. Ignace area moose were observed to feed in water at least 18 feet deep.

So, they can dive that deep and yes it is for food.