Note: Due to the unfortunate discovery made by Mike Fay on 27 March and described below, extra time was taken to communicate with the Royal Society for the Protection of Birds before publishing his findings. We will now recommence with the posting of the remaining entries from Mike’s Pitcairn Islands Expedition Journal in the proper sequence. You can follow the whole series here.
27 March 2012
Went up the hill at 6:30 to see if crakes are active in the early hours as well as late. I took the de-ratification transect trail up to the 500-meter point: no sightings. I then headed east through the little Pandanus patch and just beyond I spied a crake. But something was different. The legs were not red but black and this bird was quite small. It was a chick. Soon more little forest gnomes appeared. I counted four chicks, all the same size, undoubtedly from the same clutch. Mom was there too, but she didn’t seem to be leading the pack like a chicken would. The chicks were acting just like the mother, but not quite as adept, throwing leaves with their beaks and eating any moving animal they found. I could hear two more birds vocalizing further off. This provoked a reaction from mom. She went off and joined in the vocalization spree.
I went back to camp and had a quick breakfast of muesli. This is New Zealand muesli that has raw oats. They must have strong jaws down there; I felt like a horse eating that stuff. I packed a sandwich and headed back up the hill with Heather to go as far south as the de-rat transect led. We got to the 500-meter mark and carried on. There were tree falls along the trail. The forest was getting nice and big now; there were Pisonia trees of 25-30 inches at the base with very old spreading crowns. We were soon being followed by Henderson fruit pigeons.
These little dudes are crazy. I have never seen a dove like this. They hear movement in the woods and they come in to see what is going on. One of these guys started to come in close. He looked for a better vantage; you could tell he wanted to be closer for some unknown reason. He spied a little vine right in front and jumped down on it, about 12 inches from my face. He stared in my eyes and took off to a bit more distant branch.
There were also Henderson reed warblers at this spot. The immatures are kind of pale yellow. I swished a bit and one came to about 10 feet away. It seemed that the population of young ones was far greater than the adults which had large amounts of white. A huge amount of reed warbler breeding was recorded in the months following the rat eradication operation, so this may be an indication of a population increase in response to reduced rat numbers. They were doing what you would expect, flitting from branch to branch, devouring any invertebrate in view. One of the pigeons then started eating the fruits of a small tree in the coffee family. You could see that in only a few minutes this guy could completely fill his gullet. By the cooing we could hear here and there the doves are doing just fine on Henderson.
A bit further on we could hear what I thought was the shrill cawing of the lorikeets. Sure enough they landed only about 20 feet in front of us in an endemic tree that is common in this Pisonia forest called Nesoluma st-johnianum. This is a beautiful tree that is sometimes as tall as the tallest of trees in the forest. It has rosettes of large spathulate leaves and relatively large fruits. The parrots were there for about a minute feeding on maybe nectar or some fruits. I couldn’t get a great view. As we proceeded we continued to get softly mobbed by the fruit pigeons.
At about 800 meters we hit a wall of coral. The trail turned to the right and we were in a small corridor between two walls now. There were lots of skinks and beautiful ferns.
We got to a second crossroads in the transect trail; it was at 1000 meters. The trail continued, we followed. At about 1300 meters the trail seemed to peter out. There was a bit of a trail that went off to the right, but not very far. We tried forward but I found no sign of trail. It also seemed that there had been no rat-eradication monitoring down this way. You could tell that the trail had not been used much at all. We decided to head back to camp again and come back to do both evening and night transects to see if we could get a better figure on how many crakes we were dealing with, and also to see if there were rats.
At 5:00 PM, up we went on top again. We divided up the labor. Heather was to walk straight to 500 meters and then go left. I would go to the end of the south trail and then go up the opposite perpendicular. I left Heather at the start and I cruised out to the end. She looked pretty worried, but she had led the way back in the morning so I knew she wouldn’t get lost. What I told her was, “If you are off the transect you will know—you won’t be able to move.”
I started counting crakes at the end of the trail. At about 1000 meters I saw a single crake. As I reached about 700 meters on this main transect trail, at 6:15, I saw an animal move in pretty dense underbrush to the left of the trail. Immediately my mind said rat, but it was just a rat signature, not a sure sighting. I approached as quickly as I could before I thought it would bolt, and got my eyes down at his level and all be damned I saw this rat drop down from one branch to another and then just sit there perched.
I stood there and made absolutely positive ID, 1000 percent, of a rat that was absolutely typical, staring at it for 30 seconds. I had the video rolling. I decided to take some photos and got off three quick shots. Then I approached a bit closer after at least 45 seconds of good viewing and he bolted and disappeared into the upset coral rubble around a small uprooted Pisonia tree. I rooted around in there a bit hoping to flush him out but he was gone into the matrix.
It was an extremely weird feeling because I knew that I had just made a very important observation, but it was the last observation in the world I wanted to make.
This changed everything. Yes, it could be the only rat left on Henderson, but the probability of me seeing the only rat was like winning the Irish Sweepstakes twice. I looked at the photos and the camera had focused on branches in front of the rat. They were your classic bigfoot photos. So, I didn’t even have documentation of this fact. I recognize the skepticism that might exist, but unfortunately this observation was as sure as having a raging bull elephant at you, i.e. absolutely no question about it. I would love to be able to say, “Well maybe it wasn’t a rat”, but a rat is a rat and that was a rat.
So what does this mean? It means that even though it is extremely hard to bring bad news, the team who undertook this project needed to know as soon as possible so that a contingency plan might be put in place. When you look at the size of Henderson and the heterogeneity of the substrate, the porosity of the coral, the caves, the complex and dense vegetation, it was an enormous challenge to kill all the rats, so this team is to be commended. Of course, what I am now dying to know is what happened to the rats and crakes on the 99 percent of the island that I couldn’t get to?
By the time I left the rat site it was getting dark. When I got to where I was to turn right at the 500 m mark I saw a few chunks of coral piled on a Pisonia trunk there. I went right and there were, every 30 feet or so more rubble piles, on prominent vegetation. Heather had gone the wrong way, so I went where she was to go. She must be in a panic I thought but I figured she would be more than fine, she could just follow her markings on the way back. My brain was spinning. I walked now with my flashlight on, thinking “holy crap, I saw a rat”.
On the way back to camp I could hear what was familiar to me now after two days of walking this trail. It was like a continuous wheezing. I went to the sound and peering into the bush with my headlamp saw two Henderson Petrels beak kissing. This must be a pre-breeding courtship of some kind. There were no eggs, no nest depression.
When I got back to camp Heather was there, so that was good. I gave her the news: a rat on Henderson. What a tragic sighting.
Addendum: The Pitcairn Islands Government and the Royal Society for the Protection of Birds (RSPB), the two partners in the island restoration project, are mobilizing a trip to Henderson in response to this sighting. Their aim is to try to confirm rat presence and species, obtain genetic samples, determine whether a small number of rats survived the eradication operation or have since been introduced to the island, and to learn as much as they can about any extant rat population. They will also assess the feasibility of carrying out a hand-baiting around the area of the rat sighting and do this if possible. In the longer term, the operation will have bought precious time for Henderson’s wildlife. Millions of pairs of seabirds have been lost from Henderson since rats were introduced to the island, and the team are determined to continue their work to restore this remarkable World Heritage Site and save the Henderson petrel from its slide towards extinction.
UPDATE 4/20/2016: Four years after this observation, return trips and genetic testing have confirmed that the rats currently on Henderson are not newcomers, but are descended from survivors of the initial eradication effort, and have rebounded to a population of 50-100,000. The Royal Society for the Protection of Birds hopes to return for a second attempt at the complete removal of rats from Henderson Island.
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