Monday, March 14, 2011

Old birds!

Well all this talk of 'Wisdom', the female Laysan albatross being the oldest wild bird on record really started to get a little annoying!  Being from a little rock in the South Pacific, we seem to often fall off the face of the earth when other Nations make comparisons of oldest, biggest, longest, blah, blah...  So when (largely US) sites started crowing on about 'Wisdom' being the oldest recorded wild bird, and quite possibly what may be the oldest 'currently living' wild bird, I thought the World had gone mad and suddenly forgotten our very own NZ icon - 'Grandma'.  Generally touted as being the oldest known albatross, she was first banded in 1937 at Taiaroa Head in Dunedin.  She apparently bred through most of her life, to finally raise her last chick in 1989, not returning the next season.  Therefore, with the average age of first breeding of Royal albatross suggested to be just under 10 years of age, and the fact she was banded breeding in 1937, she was at least 61-62 years of age...or was she?

Getting a little hot under the collar about all this, I decided to investigate this a little further myself, to try and get to the bottom of 'Grandma's' actual age...just so I could set the record straight.  What has ensued has been the destruction of the basis to many of my seabird talks onboard ships, and the utter dismay that I may have lied - and been lied to - for many years!

I contacted a colleague of mine, who shall remain nameless to protect his identity.  I emailed him to see if he could shed any light on the matter.  An email arrived with what can only be described as enough information to seriously question the authenticity of 'Grandma's' record.  I'm probably opening a whole can of worms here, and may incur the wrath of God, but heck, it's not the first time and wont be the last!

A paper produced in 1993 outlines longevity of Northern Royal albatrosses at Taiaroa Head, and specifically discusses the case of 'Grandma', being one of the founding birds.  This paper can be downloaded from the CSIRO website here.  She was banded with a single colour band by Lance Richdale, a pioneering seabird biologist, and apparently very accurate and methodical worker, on about 22 Dec 1937 when she was attending a nest with an egg.  The following year she was again breeding with the same male, at the same nest, and had her first metal band and another colour band added.  The pair were variously rebanded as metal bands wore out (they were using aluminium and copper in the early days), and with various colour bands.  In 1955 her mate failed to turn up, and she was present in the early part of the season, but not seen again until November 1963.  Sounds fair?  Not really in my mind.

An explanation for her supposed absence is that it was "probably related to the small amount of time" the ranger at the time was spending at the colony due to other duties.  In support of this is the fact that several other birds (three) had similar gaps during the same period (1955-68), with the longest gap being 12 years.  These four birds are the only ones on record to have been subsequently seen after being 'absent' for more than two years.  However, this makes little sense to me, and questions whether the same birds were actually subsequently sighted.

Whatsmore, in 1963 'Grandma' turned up without a metal band (sure this could have fallen off, maybe), but with two blue colour bands.  This is despite her last actual 'recorded' colour combination being Blue/Yellow on the left leg in Jan 1952.  Apparently, these colour combinations often consisted of multiple bands of the same colour, with bands of different materials being tested.  It was also suggested that the only birds with blue colour bands in combination with a metal band were 'Grandma' and her mate...  But if records were loose enough that exact combinations and multiple bands of the same colour were being used but not adequately recorded, then is it not possible other birds were banded with blue bands?  All sounds a little tenuous to me...  That the longest lived albatross at 62+ years was one of the first ever banded at Taiaroa Head, and actual records don't definitively prove it was the same female seems all to good to be true?  Especially when around 36,000 Southern Royal albatross have been banded on Campbell Island since the 1940s and apparently there haven't been any banding records over the age of 50 (yet).  A very trusting person might believe all this, but I just don't think I can.  Withstanding all this, even if it was the same bird, the average age of first breeding at the time might have been just under 10 years, but some females were first recorded breeding at 8 years (and in the 1970s as early as 7 years!).  So this could have made 'Grandma' a mere 59-60 years!

So, go on 'Wisdom' take the crown...but you still won't be a Royal!

This bird might not be 'Grandma' but it's a beaut Southern Royal albatross for sure!

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