[Tweeters] Someone's Spoiling the Story - and the Fun.

birdmarymoor at gmail.com birdmarymoor at gmail.com
Sat Feb 6 11:36:58 PST 2021

I’m not sure they really understood the Effect. If the rate of rarities is a flat 8/1000 checklists, then if you gather 1000 people together to chase a rare bird, there will be on average 8 additional rarities found. That makes 9 rarities in one spot. Wow! That IS the Effect, as I understood it.

And they didn’t really address the other part of the Effect, which is basically that there are Hot Spots. They seem to say that eBird data doesn’t really show that there are Hot Spots; that there is a fairly flat rate of 8 rarities per 1000 checklists. But especially because of eBird, most birding is done *at Hot Spots*. They would need to have birders do extensive birding at randomly chosen locations, and then see if the rarity rate is still flat. Which we all know is not true. We are often in other spots, find no notable birds, and we don’t bother to enter checklists.

This leaves open another line of inquiry. Do megararities tend to show up at Hot Spots (that is, places where there are many species / many birds)? That would be very hard to determine, I expect, particularly as the sample size is tiny by definition. But perhaps that’s what their study *does* imply: that birders drawn to megararities are finding regular-old rarities at the same flat rate nearby *as at other Hot Spots*. So if we assume my assertions in paragraph 2, then megararities tend to show up more often at locations that are generally excellent spots to go birding, than at places that have few birds.

But, of course, megararities are more likely to be noticed at places where birders spend time, and that probably overwhelms any possible conclusions.

= Michael Hobbs
= www.marymoor.org/birding.htm
= BirdMarymoor at gmail.com

From: dick
Sent: Saturday, February 6, 2021 2:06 AM
Subject: [Tweeters] Someone's Spoiling the Story - and the Fun.

Maybe Neah Bay is over-rated?


Sent from my Verizon, Samsung Galaxy smartphone

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