South Island Robin

We moved 29 South Island robin from nearby Te Kakaho back in March and August 2013, so why so long to write it up? Laziness for sure, and reticence, lest the translocation dwindle away to a failure over time.

Island-bred robin, 2016. For a video record of nesting from hatching to fledging, please see: https://www.youtube.com/watch?v=HuiFuYydWOk

Right from the beginning of this project we thought robin would be an obvious candidate for reintroduction. They would certainly have been present before the arrival of rats in the 1800s. Peter proposed that Tinui of all the Rangitoto group of islands might be the best place to let them go as it had more forest cover than Puangiangi or Wakaterepapanui. A rep for the Tinui owners reckoned we should go with Puangiangi and presciently observed that they would end up on Tinui also in fairly short order anyway.

The project was endorsed by Ngati Kuia and Ngati Koata as gifting and recipient iwi respectively, and most of the birds were caught in August 2013 by Peter, Willie Cook, Ruby Collier, Bill Cash and Katrina Hale. Ros Batcheler who caught in March (which was mostly about kakariki rather than robin) was on hand to meet the birds, the big Ngati Koata welcome led by (the late) Joe Paul having been completed in March. Most birds were released centrally while Peter and Ruby had a quick trip down to the south to release three pairs in a piece of forest we have since dubbed Robin Bush. Free boat transport for birds and people was provided by (the late) Danny Boulton.

Courtship feeding was likely observed during the week after release, and three nests and two fledged young were seen only two months after the bigger release. A reasonable number of the original 29 have been seen over the years but we can’t really say what percentage of them formed the founder population given the difficulty in surveying all likely habitat. Two of the founders were still around in winter 2021 and it has always been a pleasure to see an old friend (minus the odd colour band) come up close to see if we are edible or will find some food for them. One of these founders is most often seen when we are weeding an area near Robin Bush, on a steep slope with very tight vegetation. It’s nice to see the elderly banded robin pop up in your little bubble when you are surrounded by a dense, scratchy botanical garden with visibility of only a couple of meters in any direction. Robin certainly add to people’s enjoyment of the island- if you don’t already know, they are confiding and aggressive. They think nothing of jumping on to your boots and picking at the laces, and I have had to shoo one off of my head repeatedly as it attempted to harvest any remaining hairs. They like to collect bugs from a scrape made with a boot, but they put paid to a favourite party trick of showing guests the pile of geckos sheltering between old sheets of corrugated iron when one quickly showed up and started scoffing the smaller geckos.

Numbers increased very strongly in the southern third of the island, but with very few being seen in the northern third until recently. In the central third around the house and nearby forest and shrublands, numbers initially built up quite well, yet we then appeared to witness two cycles of local extinction and recolonisation there. This aspect of the reintroduction made me the most nervous. Did the arguably more open forest structure allow falcon to take them under the canopy? Was there something toxic in the old rubbish dump (which we have cleaned up as best we can)? Did the larger population of kereru there compared with the rest of the island lead to disease transmission through the water supply (I did see an apparently OK robin go on to expire by the water trough a mere 15 minutes after I first saw it)? Or were we just seeing what happens in slightly less favourable habitat when food runs low seasonally? On the last point, Lynn Adams has noted on Mana over the other side of the Strait, that robin numbers go through frequent peaks and troughs, with good breeding yet apparently low survival beyond a season or so. The most obvious explanation would be that the less well established forest on Mana lacks enough food say in a dry autumn. In Wellington harbour, translocation of robin to Matiu Somes failed over a few seasons, despite breeding being observed. If there was a problem on Puangiangi it seems to have fixed itself and over the last couple of years robin have again become very common in the central area.

As of now, robin are common in the established forests and abundant in the regenerating shrublands of the southerly two-thirds. They have even colonised the heavier tauhinu scattered in the rank pasture, and are moving north, where they are now commonly seen.

Robin are probably at carrying capacity over a good part of Puangiangi. Bill Cash, who was the main force behind bird reintroductions to the almost identically-sized Motuara in Queen Charlotte Sound, estimated the robin population there at 300-600. We might be looking at a similar number on Puangiangi fairly soon. They could also easily be seen on Tinui by autumn 2016 (Colin Miskelly has documented several other examples of robin colonising islands by making sometimes quite long flights over open water; the distance to Tinui was probably not a particular challenge). A single bird was also seen on Wakaterepapanui to the north in spring 2021. I think it’s time to call Success on this one.

For a video record of nesting from hatching to fledging, please see: https://www.youtube.com/watch?v=HuiFuYydWOk

Live Nest Camera- At The Sooty Shearwater Burrow

Live on YouTube this nesting season
https://www.youtube.com/channel/UCgfpnTE2Y_2skbb_6CWhtQQ/live

The sooty shearwater breeding season has begun and this year we have a camera next to one of the nesting chambers. You can see this live on YouTube, initially for four hours a day, 9-11 AM and 8-10 PM NZDT. Outside of those hours, you can have a look at footage from previous times. You don’t have to watch the whole thing- remember you can scroll through the timeline and look for interesting bits.

This is Burrow 7 in our little sooty colony. It has been consistently successful, and the nesting chamber is close to the surface beneath a clear, flat area in the forest, so was an obvious choice for installing the camera. Interestingly, it has often given a false negative when burrowscoping, implying that the chick and adults can move quickly beyond the reach of the burrowscope and its annoying light. No such problem with the 850nm IR lights on the camera used here. There has been zero interaction with the camera so far and the birds seem entirely unconcerned, including when the camera whirrs and clicks when powered on each session (you can see that at the start of a lot of the archived clips, where the PTZ goes through its range of motion before settling on the preset).

The birds came back to their burrow probably in late October, then went away to sea again for a month or so. During that time I installed the camera. They came back on 25 November. I first saw their single egg on 29 November. They will share incubation for 53-56 days until hatching. So far we can see some great pair-bonding behaviour, and general activity around incubation, nest material rearrangement, preening, sleeping, trying not to get too bored, etc.

You may wonder why the feed is live for only four hours a day. The setup is powered from an 80W solar panel with attached 100Ah 12V LiFePO4 battery. The battery provides power to a modem/router drawing 1-3W so the feed can get to the outside world. The camera is powered by a POE injector, and draws about 11W with the IR lights on, which is all the time. The set-up might well allow for the camera to be powered throughout the day in mid-summer, but the chick will hopefully fledge in early May, when the solar panel will be seeing a lot less sun. The other main limitation is the amount of data that can be transferred. The feed uses 2.1 GB per hour in 1920X1080 full HD. I have bought a broadband plan that gives 120 GB peak and unlimited off-peak data in a month. The two hours from 8-10 PM daily will chew through the entire 120 GB in a month. The off-peak broadcasts will hopefully be able to be extended once I next visit and check how much strain the battery has been under. Later I’ll post details of the set-up for anyone who has a similar remote broadcast interest.

I have limited control of the camera and sometimes the streams will start, sometimes not. Hopefully we can watch activity at the burrow right through till fledging in early May, but who knows what will happen. This is not a guaranteed successful nest, but fingers crossed.