Ship-assisted vagrants (1 Viewer)

[Sancho]

I was wondering about something an old friend told me...he used to work at sea, had a mild interest in birds, and said that birds of all sizes would regularly appear on board, hitch a ride, and fly off at first sight of distant land. He and his mates used to leave out food for them.

So if a bird is suspected to have made a ship-assisted sea-crossing, is it still counted as a vagrant record by Rare Birds Committees?

Also, is there any estimate of the percentage of passerine trans-atlantic vagrants that are actually ship-assisted?

 

[joannec]

So if a bird is suspected to have made a ship-assisted sea-crossing, is it still counted as a vagrant record by Rare Birds Committees?

I think I read on BF awhile ago, in connection with the Great Blue Heron, that ship-assisted is accepted as a vagrant. Also the white crowned sparrow in Norfolk was considered most likely to have been ship assisted. Apologies if I'm wrong.

 

[Cheshire Birder]

I think a large number of the american sparrows in particular are ship assisted. As for other american landbirds, the chances are a good proportion of them are ship assisted given the locations (i.e. proximity to large ports).

CB

 

[Steven Astley]

In my opinion known ship assisted or those with a high probabilty of their vagrancy being due to ships shouldn't be accepted by rare bird committees.

 

[Tractorboy69]

If a bird is fed whilst on deck then that does prevent its inclusion onto the British List as it is deemed to have arrived with human assistance rather than in a natural state, but the simple act of landing on board a ship is deemed ok as its no different to landing on a piece of flotsam to survive and maybe recover some strength. If a bird is fed on a ship then this is viewed as interfering in its natural migration as it may not have survived the journey without that food so in effect arrived here artificially.

Obviously in many cases we probably wouldn't actually know if a bird had or hadn't hitched some, or most of the way, by boat, or whether it had been fed or not if it had, although there are instances where we are aware of such circumstances such as the Catbird that arrived in Southampton on the QEII having been fed during the journey (and which even stayed on board and subsequently toured the Med!), and the Snowy Sheathbill that was brought back to Plymouth from the Falklands and which in addition to being fed, I think had even been taken below deck!

There is undoubtedly a good number of birds that land on ships in the Atlantic, especially near to the eastern seaboard of the States, but as to the percentage of vagrants that survive a crossing that way and arrive here would be guesswork, but certainly as already mentioned species such as Sparrows are far more able to make the crossing that way than insectivourous species, and the location of landfall such as Seaforth (Song Sparrow & Blackpoll Warbler) and Landguard (Lark Sparrow) etc is another clue to their potential method of arrival.

I remember being shown a dead American Robin at Felixstowe Docks once which had been found on a container boat which was pretty galling as I still needed it at the time and had even been all the way to Scotland (Inverbervie) and failed to see one!


Simon

Edit: In 1986 the BOU amended the definitions regarding ship-assisted vargrants that were barred from Cat A from birds 'which have certainly arrived with ship assistance' to birds which 'certainly arrived with a combination of ship and human assistance, including the provision of food and shelter'

 

[Mysticete]

In contrast, AOU/ABA does not any accept ship assisted birds, which I think has resulted in Nazca Booby and a few other records being rejected. The only exception I can think of are the Pennsylvania Jackdaws, who were ship assisted but bred for some years.

 

[Monahawk]

I find the non acceptance of ship assisted birds daft. It's just another prickly rule by the various rare bird commitees.

So long as a bird has not been captured for domestic purposes, ie as for pets or collections and then released accidentally or on purpose, then I can see no problem in allowing a ship assisted bird to be rcorded as genuine. After all the bird probably just sees a ship or such craft as a form of land on which to rest and possibly feed. Birds do get fed on ships by sympathetic travellers or crew members but so what, we birders are feeding wild birds all the time artificially in gardens, parks and nature reserves. Does that mean we can't accept them because this is human interference too.

Maybe I am missing the point here, but some rules in birding make my blood boil.

It's just unfortunate the bird on the ship has ended up in the wrong destination. The next time an exotic species [so long as its not captive] flits off the cargo ship or ferry at Cork, Liverpool, Southampton or where ever........TICK IT! And damnation to the commitees.

 

[Steven Astley]

Yes I think you are missing the point
The most famous, for example, The British List is more than just a list for birders to use for listing purposes. See below
http://www.bou.org.uk/recgen.html
Alien species cause havoc threatening native species. If a species was to colonise an area as result of ships it's an alien species. That's why I don't think they should be included or they should at least have its own category. Boats are man made mini eco systems. Birds that make it here by ships are not natural vagrants in my opinion

At the end of the day people can include what they want on there personal lists or choose whatever listing organisation there is out there, which are unfairly often poo pooed. IMO The British List should remain scientific above serving the purposes of competitive listers.

 

[Monahawk]

Ok, fair comment on some points there Steve, but how come some accidental colonies of insects, mammals and plants which come to the UK/Ireland arising from ships soon get accepted into these nations flora and fauna lists even though we know them as aliens. Why should it be any different for birds?

Is it that these acceptance commitees don't trust the birding public enough or is it because science is king?

Too many rules man, far to many rules.