Following completion of the first round of rat baiting on the three motu known to have rats, the team from Te Ipukarea Society had 10 days before doing a second round of baiting on the same islands.
During this time they conducted bird surveys for all the motu of Suwarrow. They started with the Gull Islets, just east of the passage into Suwarrow’s lagoon.
There were many greater and lesser frigate birds (kota’a) nesting side by side in the low shrubs of Pemphis (Ngangie).
“The team saw both eggs and chicks. There were also several species of booby birds, and a few sooty tern (tara) eggs,” said TIS technical director Kelvin Passfield in a telephoned report.
The next day the team did the two small kena motus, close to Motu Tou.
“Again many kota’a were nesting, and there were also brown booby (kena) nests on the ground, with eggs and chicks,” said Passfield.
“Despite their small size, these islets also had a surprising number of nesting red-tailed tropic birds (tavake). In the afternoon the team surveyed Motu Oneone, at the eastern extremity of the atoll. This island had mainly torea, and the team also spotted a tavake, a masked booby (lulu), and a long-tailed cuckoo (karavea).
“Over the next few days the team surveyed Entrance Island and New Island, situated at the south east of the atoll, where they found a high number of nesting tavake,” said Passfield.
“We also went to Brushwood and One Tree islets, in the north, and this is where we found very high numbers of tara and their chicks. A few of their eggs were still evident as well, not yet hatched. Turtle Island was also surveyed, and was interesting because of the almost total absence of birds.”
Manu Island in the north west was next on the team’s list and true to its name, the bird island had among the highest density of birds found.
The following week the team completed the bird surveys on Gull Islets, and Seven Sisters, in the north east, where three lulu, a number of tara and their chicks, and the usual kena and kotaa were nesting. A number of black and brown noddies (ngoio and takia) were observed roosting on branches, the first of the rakia having started to build nests.
“Whale Island, near Anchorage, was the last to be surveyed, and had mainly tara and kota’a, with a few red footed boobies (toroa), that had just started to nest, and some black and brown noddies perched on dead tree branches of ngangie,” said Passfield.
“The largest islands, Anchorage Island and Motu Tou, did not have much in the way of birds present, but an earlier presence of Rakia nesting could be seen among the towering canopy of tou trees.”
Passfield says a notable find on all the motu were the high number of fish aggregation devices that were found washed up, with more than 50 being found.
“Many of these still had their locator beacons attached. This large number suggests that the estimate of 100,000 of these FADs, set by purse seine fishing boats and drifting around in the West and Central Pacific Ocean is no exaggeration.”
The team found two FADs with the remains of dead turtles entangled in the netting. Together with these more than 50 FADs was a large amount of other abandoned fishing gear including buoys, nets, lines and ropes.
“Plastic bottles and other plastic rubbish was everywhere on all the motu,” said Passfield.
Overall the team counted around 8000 kota’a, 750 tavake, five lulu, 160 kena, 285 toroa, and 300 white terns (Kakaia).
Several waders were also spotted, including six of the globally-threatened bristle-thighed curlew (teue) as well as reef herons (kotuku), Pacific plovers (oorea), and wandering tattlers (kuriri). Two karavea were seen, and several more were heard.
“Estimating the number of tara was difficult, as the eggs had mostly hatched and young chicks (runners) would hide in the vegetation,” Passfield said.
“When we approached the colonies tens of thousands of adult tara would take to the air. Previous estimates of over 100,000 were supported based on these observations.”
Passfield says the number of birds found on Suwarrow support the internationally recognised “Important Bird Area” (and key biodiversity area) status of Suwarrow, and the conservation efforts being made to protect the Atoll including ensuring it remains free of harmful invasive species such as rats, cats, ants, weeds and others.
The survey work was supported under a grant from the Cook Islands GEF Small Grants Programme, the Packard Foundation, and David and Sarah Gordon.
The TIS team will return to Rarotonga soon aboard the Cook Islands General Transport barge Layer Mas.