I'm somewhat hesitant to add another post to a thread that has long been generating more heat than light. But I genuinely can't help wondering:
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if enough ivory-bills survived the 1940s that the survivors constituted a viable breeding population (and how many individuals would that have to be?);
- given that 70-odd years has now passed, hunting pressure hasn't been an issue for decades, and there appear to be large areas of suitable habitat;
- would the population be expected to increase? Presumably yes; and if so, what would the rate of increase be likely to be?
- would each generation not have become less shy, due to never or hardly having experienced hunting pressure? If the birds are thought to have a 15-year lifespan, the period 1945-2020 that means at least five generations. I can credit that the birds might have become shyer due to hunting pressure, but with the cessation of hunting pressure there's no reason why this should reverse, and there are plenty of examples of other birds and animals becoming less shy/easier to spot after hunting pressure or human interference was let off - I've cited a few in
my post #250, including the stork-billed kingfisher, a bird that back in 1920s Singapore was said to be wary enough to flush 100 yards ahead of a boat, but is now easy to approach and photograph.
- Taking into account all the above, plus the birds supposedly being quite mobile, why hasn't the species been rediscovered by now? I mean definitively rediscovered - as in photos or video footage that doesn't need to be National Geographic/BBC quality, but shows adequate field marks? The imperial woodpecker footage from the 1950s certainly isn't great quality, but is more than able to show the distinctive features well enough so that the bird can be clearly identified as such, without having to delve into flap rate. Birds thought to be extinct, like the takahē and the night parrot, and including much smaller species than a crow-sized woodpecker, have been rediscovered without needing every square mile of their range being combed - and by "rediscovered" I mean conclusively so, not just via calls, tracks, or sign. If birds like these can be rediscovered, why not the ivory-bill?
I've read some of the accounts from people who have spotted them, especially David Kulivan. I can fully believe Kulivan was sure of what he was seeing. But over 20 years have passed and much effort has been put in, and no one has succeeded in gathering photos or video even comparable to the 1956 imperial woodpecker footage. Back in 2006
fishcrow (Mike Collins) asserted that "
In a few years, people will look back at this time and wonder what the controversy was all about. They will also realize that ivorybills were just waiting to be discovered in several locations." With better and better equipment being available to searchers in the field, how many more years do the "believers" think will pass before a definitive photo or video is recorded? And if no such evidence appears, how long will it take before it's accepted the bird is in fact gone?