Mega Seabirds - The Unofficial Records! (1 Viewer)

[Helsinki Birder]

Yes - deliberately basic as I felt a full explanation of Bayes' theorem would be overkill. That doesn't negate the point though.

With regards to a bird so distinctive that its ID becomes instantaneous, the key issue is whether ID is beyond any doubt, in which case, yes indeed, a priori probability is irrelevant, as the theorem shows. Often that isn't the case though.

With regards to whether a record should not be based wholly on what was seen by the observers, I disagree entirely for the very reasons I outlined. A lot more evidence should be needed to support claims of a yellow-eyed penguin in UK waters than a Sabine's gull. It's why there are "description species" in the first place.

If an odds based approach did eliminate most major records then in my opinion, eliminating them is the correct decision. I don't think it would though (and it certainly wouldn't if ID was beyond any doubt) - its just a question of making an appropriate judgement of the weight of evidence versus the likelihood of it occurring in the first place and to do this, I think it helps to understand how the numbers work.

Doubt is a frame of mind Ilya, and subjective to the personality of the doubter, which in and of itself is subjective to a vast array of factors in its psychological make up. Its a mirror reflected in a mirror and leads no where.

Empiricism means that you stick to evidence and evidence alone. Avoiding the subjective. Whether a verbal description, regardless of its detail is considered evidence is another matter. In reality the only evidence ever obtainable in such a scenario is visual images. And the percentage of rare seabirds which are photographed at all is very low, due to the nature and logistics associated with seawatching.

So how then do you judge a rare seabird record, without such evidence?
Well realistically in such a scenario, the detail of the description only matters to the reviewer if it contains features which are anomalous for the species being described, in which case the reviewer can safely say it was not what it is claimed as.

If the record is a perfect description for the species, it really does not matter, as either (A) it is being judged on numerical probability in your case. or (B) faith in what has been described was accurate/true/ not false/ not string.

In which case....why write a description at all, if the content of it only matters if its wrong?

Owen

 

[Ilya Maclean]

Doubt is a frame of mind Ilya, and subjective to the personality of the doubter, which in and of itself is subjective to a vast array of factors in its psychological make up. Its a mirror reflected in a mirror and leads no where.

Empiricism means that you stick to evidence and evidence alone. Avoiding the subjective. Whether a verbal description, regardless of its detail is considered evidence is another matter. In reality the only evidence ever obtainable in such a scenario is visual images. And the percentage of rare seabirds which are photographed at all is very low, due to the nature and logistics associated with seawatching.

So how then do you judge a rare seabird record, without such evidence?
Well realistically in such a scenario, the detail of the description only matters to the reviewer if it contains features which are anomalous for the species being described, in which case the reviewer can safely say it was not what it is claimed as.

If the record is a perfect description for the species, it really does not matter, as either (A) it is being judged on numerical probability in your case. or (B) faith in what has been described was accurate/true/ not false/ not string.

In which case....why write a description at all, if the content of it only matters if its wrong?

Owen

Self-doubt is indeed a frame of mind as is its antithesis. Certainty sensu-stricto isn’t though.

Yes, empiricism usually means sticking to evidence, but evidence can take many forms. A prior history of turning up in the East Atlantic or the fact that shearwaters fly and penguins don't, is also evidence.

 

[Jane Turner]

A prior history of turning up in the East Atlantic or the fact that shearwaters fly and penguins don't, is also evidence.

On 18 July 2002, salmon fisherman Guy Demmert caught an adult Humboldt Penguin (Spheniscus humboldti) in his purse seine net off Noyes Island, Alaska (55[degrees] 30' N, 133[degrees] 40' W), nearly 10,000 km from its native range in Peru and Chile (from 5[degrees] S to 42[degrees] S). The penguin appeared healthy and robust, and was released unhurt alter being photographed (Guy Demmert, pets. comm.) (Fig. 1). This may not have been the first sighting of penguins in Alaska. A 1976 research cruise in the Gulf of Alaska recorded "brown penguins" (M. J. Rauzon, pets. comm.), and Guy Demmert (pets. comm.) saw a penguin while fishing in 2001.
Wilson Journal of Ornithology, The, June, 2007 by A.N. Van Buren, P. Dee Boersma

I also have a memory of recent records of I think King Penguin, off Brazil.

Its one of the fun things about seabirds that they do turn up and survive half a hemisphere off course - not that I'm getting involved in the empiricist debate.

 

[Helsinki Birder]

Self-doubt is indeed a frame of mind as is its antithesis. Certainty sensu-stricto isn’t though.

Yes, empiricism usually means sticking to evidence, but evidence can take many forms. A prior history of turning up in the East Atlantic or the fact that shearwaters fly and penguins don't, is also evidence.

Well, Janes research aside, The penguin analogy is a tad overboard I think you would agree Ilya.

When seabirds such as "true seawatch species" (various tubenoses is what i mean here), including mega rare southern hemisphere and tropics species, which have been proven through new technology to undertake even more amazing, long distance journeys than we had previously thought possible, the aim should be to be on the lookout for more and a wider vareity of these species, rather than overboard scepticism in regards to their reports.

Yes I agree having a track record of species showing up does help, however seabirds are a rather special case, they dont end up in nets, on headlands, or shot as in the old days as many passerine and wader species for example, used to be.

So we are at a disadvantage in terms of the sampling size of such species on the historical record. In this case, lists of mega rares that never made the official books are very interesting, as they could very well be that historical record. A list of species that perhaps we should be gen-ing up on, paying more attention to and keeping an eye out for.

One thing is for sure. These things are out there. And fair play to the jammy observer who is lucky enough to have one go by him/her.

regards

Owen

 

[Ilya Maclean]

Wow that's pretty amazing Jane - I can't hep wondering about zoo escapes though.

Owen - I agree that there's a real possibility of mega rare with seabirds, but surely there's some merit in sorting the wheat from the chaff

 

[Richard Klim]

BTW - anybody knows a list of seabirds seen off East N America? These waters had much more rare seabirds, eg. many Herald Petrels, and this can be a prediction of what turns in N Atlantic.

Rare (to the British Isles!) tubenoses recorded off the Eastern Seaboard:

• Atlantic Yellow-nosed Albatross (4)
• Black-browed Albatross (5)
• Trindade Petrel (3)
• Bermuda Petrel (3)
• Black-capped Petrel (2)
• Fea's/Zino's Petrel [almost certainly Fea's] (3)
• Bulwer's Petrel (5)
• Cape Verde Shearwater (5)
• Audubon's Shearwater (1)
• Barolo Shearwater (5)
• White-faced Petrel (3)
• Black-bellied Storm Petrel (5)
• Swinhoe's Petrel (4?)
• Madeiran Petrel [mostly 'Grant's'?] (2)

[Numbers are ABA abundance codes: 1 = common; 2 = uncommon; 3 = rare; 4 = casual; 5 = accidental.]

Richard

 

[Helsinki Birder]

Owen - I agree that there's a real possibility of mega rare with seabirds, but surely there's some merit in sorting the wheat from the chaff

Always Ilya.

But when it comes to seawatching records, 99% of rarities (even "commoner" stuff like Wilson's, Fea's types, "Little" types and various med species, or dark rumped petrel types, band rumped types etc etc) will go un-photographed.

Therefore when assessing these rarities, you are not using evidence (as I said above, a description does not necessarily constitute evidence if the details contained therein are not taken as BEING concrete evidence). It then becomes a matter of do you believe the record and the person claiming it.
Which is not empiricism.

The question then becomes....was it actually "assessed"?
The answer is of course, no. It was simply weighed in terms of "belief" or "faith". Which has no process, and is simply an opinion, as opposed to deliberation on fact.

Owen

 

[Ilya Maclean]

Always Ilya.

But when it comes to seawatching records, 99% of rarities (even "commoner" stuff like Wilson's, Fea's types, "Little" types and various med species, or dark rumped petrel types, band rumped types etc etc) will go un-photographed.

Therefore when assessing these rarities, you are not using evidence (as I said above, a description does not necessarily constitute evidence if the details contained therein are not taken as BEING concrete evidence). It then becomes a matter of do you believe the record and the person claiming it.
Which is not empiricism.

The question then becomes....was it actually "assessed"?
The answer is of course, no. It was simply weighed in terms of "belief" or "faith". Which has no process, and is simply an opinion, as opposed to deliberation on fact.

Owen

There's a difference between blind faith and informed belief, but perhaps we should stop hi-jacking this thread and allow it to return to its original topic? I'm happy to continue the debate in private.

 

[Jane Turner]

Wow that's pretty amazing Jane - I can't hep wondering about zoo escapes though.

Hmm I'll never find it again, but I did see something about authentic southern ocean parasites. I wasn't looking for the Humboldt's, it was the north atlantic King Penguin records I was chasing!

I do sometimes wonder why I bother seawatching, since I've already seen all the birds that can be identified without any doubt on the views I'll get from home and when I do see something out of the ordinary, I'll be in situation I was last year with my Fea's type.

 

[Andrew Whitehouse]

I also have a memory of recent records of I think King Penguin, off Brazil.

Its one of the fun things about seabirds that they do turn up and survive half a hemisphere off course - not that I'm getting involved in the empiricist debate.

Magellanic Penguin turns up quite regularly in Brazil (even I've seen one there!). I think there are records of other penguins too. Would be nice to get one in this part of the world, although a bit of a shock I suppose.

 

[jurek]

On 18 July 2002, salmon fisherman Guy Demmert caught an adult Humboldt Penguin (Spheniscus humboldti) in his purse seine net off Noyes Island, Alaska (55[degrees] 30' N, 133[degrees] 40' W), nearly 10,000 km from its native range in Peru and Chile (from 5[degrees] S to 42[degrees] S).

Humboldt and several other species of penguins were seen in Europe as escapes.

 

[lewis20126]

Rare (to the British Isles!) tubenoses recorded off the Eastern Seaboard:

• Atlantic Yellow-nosed Albatross (4)
• Black-browed Albatross (5)
• Trindade Petrel (3)
• Bermuda Petrel (3)
• Black-capped Petrel (2)
• Fea's/Zino's Petrel [almost certainly Fea's] (3)
• Bulwer's Petrel (5)
• Cape Verde Shearwater (5)
• Audubon's Shearwater (1)
• Barolo Shearwater (5)
• White-faced Petrel (3)
• Black-bellied Storm Petrel (5)
• Madeiran Petrel ['Grant's'?] (2)

[Numbers are ABA abundance codes: 1 = common; 2 = uncommon; 3 = rare; 4 = casual; 5 = accidental.]

Richard

Nice summary - I think most records of the rarities have been photographed on pelagic trips unlike the list of possibles, probables and assorted others claimed from the coastal headlands of B&I. Its probably a good summary of what to expect in the Gulf Stream - at decreasing frequencies further east?

cheers, alan

 

[Richard Klim]

Nice summary...

...Swinhoe's Petrel added (accepted by AOU-NACC, Jul 2010).

Richard

 

[Mysticete]

In regards to Band-rumped, depending on how you split the species, there is evidence that at least 2 forms regularly occur off of North Carolina.

 

[Richard Klim]

In regards to Band-rumped, depending on how you split the species, there is evidence that at least 2 forms regularly occur off of North Carolina.

Yes. 'Grant's' has been confirmed by a ringing recovery, and also fits well with regular dates of occurrence and moult condition. Robb et al 2008 suggests that the second 'type' observed off the E coast might just reflect individual variation, or could possibly be the other cool season breeder, Cape Verde Storm Petrel (jabejabe - should've been named Flintstone's Storm Petrel!).

Congrats on your recent NC Band-rumped, Morgan. Any idea which one? ...or both?

[And envious of Black-capped Petrel - must do a NC pelagic some day!]

Richard

 

[jurek]

Thanks for the summary!

Cannot think about the number of pelagic trips in N America vs Europe.

How many individual pelagic trips are organized in the whole West Palearctic per year? A few? Less than 20?

When you think how few observers go out there, many so-called rare seabirds must be actually rather common. Imagine that you would watch migration of land birds with the same intensity - you would miss plenty of not so rare species.

 

[Richard Klim]

Cannot think about the number of pelagic trips in N America vs Europe.

How many individual pelagic trips are organized in the whole West Palearctic per year? A few? Less than 20?

But on the US Eastern Seaboard, pelagic trips are almost essential - there are few prominent headlands to concentrate seabirds, and deep waters are anyway generally far offshore.

In contrast, SW Britain and Ireland are major obstacles with numerous covenient (for birders, not birds!) rugged headlands and deeper inshore waters.

Richard

 

[Richard Klim]

Rare (to the British Isles!) tubenoses recorded off the Eastern Seaboard...

Late news! Possible White-chinned Petrel off ME on Tuesday would be the 3rd ABA Area record (1st: TX, 1986; 2nd: CA, 2009) and 1st for the Eastern Seaboard.
http://birding.typepad.com/peeps/2010/08/possible-whitechinned-petrel-bar-harbor-maine.html

Richard

 

[lewis20126]

with numerous covenient (for birders, not birds!) rugged headlands and deeper inshore waters.

Richard

Not sure about the deep inshore waters bit - compare the shelf drop off at Hatteras with that of Cornwall / Cork etc - I don't think our trips get close..off the cuff aftre 6 pints so need to check the maps...

a

 

[Richard Klim]

Not sure about the deep inshore waters bit - compare the shelf drop off at Hatteras with that of Cornwall / Cork etc - I don't think our trips get close..off the cuff aftre 6 pints so need to check the maps...
a

Even after 6 pints, you're right! I was thinking more about land-based seawatching - the US east coast is mostly quite 'smooth', with gradually shelving sand, mud, marshes etc, rather than prominent rocky headlands. But a Hatteras pelagic will certainly reach much deeper waters than possible anywhere off SW Britain.

Richard B