October 2022

After searching tawaki in Tamatea / Doubtful Sound for five days, we have some good but also some slightly worrying news.

The good news is, that we recorded a total of 203 nests on 16 different islands in the fjord. Considering that there are supposed to be more than 700 islands in the Breaksea/Dusky fjord complex, we might have barely scratched the surface of the question about the total tawaki population numbers in Tamatea. Considering that the official numbers for the fjord (dating back to surveys in the 1990s) is only 9 nests, there are a lot more penguins than anyone would have thought.

Some of these islands are unsuitable for tawaki. Not because there wouldn’t be adequate breeding habitat, but because of the flourishing fur seal population in the fjord. Some of the islands are literally overrun by fur seals, especially pups and lactating mothers. The pups are small enough to cuddle up with a penguin in their burrow. Something Myrene Otis actually directly witnessed and documented. This likely makes for a rather uncomfortable breeding experience.

However, on other tawaki islands that were free of fur seals, we found some other worrying signs.

During our searches we came across quite a few tawaki nests, that were neatly prepared with fresh sticks and leaves for this year’s breeding season, but unoccupied. This generally means, the male penguin had returned and got the nest ready to impress his partner upon her return. Only she never showed up – most likely because she did not survive the winter migration.

Now, one could think that this may happen especially considering that we are entering the third year of a strong La Niña which is known to have negative effects on New Zealand penguins. If that were the case, we would have expected to see similar patterns in Doubtful and Breaksea Sound. But we didn’t which potentially points at a localized effect, an effect that only affects tawaki in Dusky Sound.

It is too early to speculate about what may be going on in Dusky. But at any rate, it means that we have our work cut out for the coming years.

Figure out if something’s wrong in Dusky. And what’s wrong.

For the longest time, tawaki have been touted as “the rarest penguin species in the world”. Until recently, the IUCN redlist gave a total world population of tawaki estimate of only 7,000 mature individuals. Yet, survey work carried out by the Tawaki Project but especially Robin Long in the past decade has cast some serious doubts on the validity of this claim. In fact, the IUCN has revised their estimate since to 12,500-50,000 individuals. (Although some still haven’t caught up.)

So what’s up? Are tawaki numbers increasing even though the official assessments still considers the species in decline? Or have tawaki numbers been underestimated previously? To answer this question, we have to look at where the 7,000-individuals-number comes from.

It is based on a series of surveys carried out in the early 1990s. These surveys were primarily financed through the participation of tourists that paid for the privilege to visit some of the remote sites in Fiordland and search for penguins in the process. With tawaki not the easiest bird to find there is certainly the suspicion that search parties consisting primarily of tourists lacked the necessary experience and potentially enthusiasm to crawl into every hole in the ground to see if there are penguins in there.

But then there are the John Islands in Te Puaitaha / Breaksea Sound.

During the 1990s survey, the search parties found a total of 9 nests when searching four of the five islands in the group. So when we stopped at the John Islands on our way to Dusky Sound, we thought we had to look for a bunch of needles in a haystack. Well, turns out, in just a couple of hours we found 43 tawaki nests – more than four times as many as the 1990s survey.

While we often had the suspicion that the inexperience of the search parties back in the day resulted in the low penguin numbers, it seems difficult to imagine that inexperience was behind the low return of just nine nests in the 1990s. You have to walk around blindfolded not to spot the burrow entrances!

So, it would appear that penguin numbers on John Islands at the very least have increased in numbers since the 1990s. That is not to say, that inexperience of the search teams 30 years ago did not contribute to the low population estimate that we stuck with for almost as long. As with everything, it generally is a combination of different factors that determine what we see.