Richard Wells, a highly regarded NZ seabird and fisheries specialist, recently spent time on The Snares islands undertaking bird counts for the 2014 Southern Buller’s Albatross census.
“My recent experience being a part of a field team making a full census count of Southen Buller’s albatross (aka mollymawk) on the Snares as left an indelible mark on me. Not only was it a trip to a place rarely trod by any human, a complete break from normal email life and a time spent with lovely and wise people - it was also a place to discuss and reflect on the ecology of the birds, the islands and the region and the way the parts shift and merge in constant change on both short and very long time scales.
Not quite an epiphany but nearly… as we looked at how all the mollymawks around New Zealand choose their time and place to breed without great overlap, how their migration patterns to feed overseas are staged and how critical safe island sanctuaries for breeding are to both them and many other seabird species”.
The Snares islands lie about 70 nautical miles south of Stewart Island and have done so for millions of years, in fact the 3-7 metres of peat that now covers these granite outcrops has taken 10 million years of vegetation and seabird poo to form.
Its lack of good fresh water (seabird poo again!) and anything remotely like a safe harbour has meant these islands have never been settled and hence invaded by the usual mammalian predators brought to NZ shores.
Thus The Snares have had essentially uninterrupted millennia to build up an internationally significant and highly protected seabird breeding population plus some endemic species and sub-species all to itself (for instance the Snare’s crested penguin, snipe and tomit).
Around 3.5 million sooty shearwaters use the Snares as their maternity ward every spring/summer, burrowing into the soft peat all over the island (along with many other burrowing birds such as the much smaller diving petrel).
This island group is also the breeding place of most Southern Buller’s albatross (the rest have chosen the Solander Islands as their preferred spot and all spend 2-3 months a year off Chile, feeding) and this population has been subject to a consistent time-series of studies since 1969. The last full census of the population (counting every nesting bird rather than just the study sites) was undertaken in 2002, so this year DWG, DOC, MPI and NIWA worked closely together to resource another full census.
NIWA’s Paul Sagar first studied these albatrosses in 1976-77 and has lead the research here for over 20 years, so was naturally the head of this team, with Richard Wells and his daughter Tamar (a marine science student at Victoria University) volunteered as ‘Sagar’s little helpers’.
“After a sometimes smooth, sometimes damn bumpy 20-hour yacht trip we were dropped off at the small huts on the Main Island with food, binoculars and sense of purpose”.
The census is undertaken by using maps of previous surveys and counting off each nest with an egg in it (or sitting bird). In the forest this is hard work but relatively easy compared to the cliffs which comprise nearly the entire coastline; here binoculars are used and counts all written down and cross referenced statistically later.
The going is heavy in thick scrub, soft ground underfoot (avoiding the literally millions of seabird burrows and the occasional grumpy sea lion kipping far from shore) and strong “breezes” usually with added moisture (not summer really).
“We were in full wet weather gear nearly every day – rain and sweat! Each day we ticked off another section of the island.
We were able to not only complete a full census but also visit all the study sites at least twice and there band new arrivals to the area, as well as check up on previous birds. We re-sighted four birds that had been banded in 1972! This information is invaluable to understand how often adults are breeding and what their average survival is”.
“So we left the island as we found it, tired, satisfied and somewhat pecked - some birds don’t give up their identity without a fight(!) - and we enjoyed calm seas on the return voyage”.
The 2014 census resulted in around 8,000 pairs of Southern Buller’s being counted - remarkably similar to the 2002 count and around double the number reported breeding in 1969.
Richard Wells, Seabird and Fisheries Specialist