October Club Night Report

All change for Broughton Island

In another successful zoom presentation Alan Stuart outlined a brief history of Broughton Island, the breeding seabirds, terrestrial and coastal , residents and vagrants, the Silvereye story, the seabird nest boxes and how the island is changing.

The island has a long history of indigenous use for collecting seabird eggs and chicks, and fishing. There were then small settlements at Esmerelda Cove and Providence Beach after European discovery. This was followed by over 100 years of invasion by feral plants and , including goats, cats, rats and rabbits, as well as frequent fires. In 1972 the island was included in the Myall Lakes National Park and in 2009 rats and rabbits were removed. The HBOC/NPWS terrestrial study began in 2012, initially as spring and autumn surveys and quarterly from 2017 onwards combined with a banding study.

Breeding Seabirds: In 2009 it was estimated that there were 55,000 pairs of Wedge-tailed Shearwater present and that number has increased. There were also 200 to 300 Short-tailed Shearwater, a decrease from the 1970’s. Among other breeding seabirds are 24 to 43 pairs of at 5 landing sites and Gould’s Petrel that are now using artificial nest boxes on the island.

Shorebirds: There are 25 to 35 Sooty Oystercatchers with several breeding pairs. This makes Broughton Island one of the most important breeding sites in the Hunter Region. Other shorebirds include Red-capped Plover, Pied Oystercatcher, Ruddy Turnstone and Double-banded Plover. The critically-endangered Beach Stone-curlew are known to be breeding nearby and 2 birds were found on Broughton Island for the first time this year. This could be the start of something.

Gulls and Terns: 50 to 100 pairs of Silver Gull are breeding near Looking Glass Bay and 5 to 10 pairs at Esmerelda Cove. There are also 50 to 100 pairs of Greater Crested Tern breeding near Looking Glass Bay.

Up to 6 Eastern Reef Egret are regularly recorded and are probably breeding. Lewin’s (mostly heard) and Buff-banded Rail are often recorded and there is one known breeding record of the Buff- banded. Other waterbirds include Great Cormorant, Great Pied Cormorant and occasionally Little Pied Cormorant, White-faced Heron, Little Black Cormorant, Australasian Gannet and Australasian Darter.

Twelve species of birds of prey have been recorded since 2012, including 4 to 6 White-bellied Sea- Eagle that visit daily, Osprey that breed annually, 1 or 2 Whistling Kite and Swamp Harrier visit regularly,Black-shouldered Kite and Brown Goshawk occasionally and there were autumn records of Spotted Harrier in 2013 and 2014.

Terrestrial Birds: The very common terrestrial birds on the island include Tawny Grassbird, Golden- headed Cisticola, Brown Quail and Welcome Swallow. Less common are Yellow-faced Honeyeater, Little Wattlebird, , Pheasant Coucal and Willie Wagtail.

Alan than gave an outline of the 3 subspecies of Silvereye seen on the island. An amazing 550 Silvereye have been banded on the island since 2017. It is now clear that there is a core population of the cornwalli subspecies, either resident or regularly visiting. There are two annual influxes: of southern birds (westernensis and lateralis) in autumn/winterand of cornwalli birds in spring, probably attracted by the fruiting Tree Broom Heath which is now prolific in parts of the island. There are no records of the banded southern birds returning. Only the more common cornwalli birds have been re-trapped in a following year.

Seabird nest boxes: six Gould’s Petrel nest boxes and nine White-faced Storm-Petrel nest boxes were installed in 2017 using 2016 Twitchathon funding. Birds were attracted using dedicated call playback at night. The first Gould’s Petrel arrived in late 2018 and the first chick was found in the 2019/20 season (fledged in April 2020). The next exciting discovery was that a nest box was visited by a Pycroft’s Petrel, sharing a nest box with a Gould’s Petrel. A Pycroft’s is a species and is so rare here that it does not even appear on the modern Australian checklist! This may be a sign of things to come.

Vagrants: About 25 land species have ‘turned up’ for brief visits, possible precursors for future colonisation. Mostly these have involved nomadic or migratory species. Some interesting visitors have been 3 Forest Raven in 2013, 4 Horsfield’s Bronze-Cuckoo in 2017, an Eastern Yellow Robin in 2019 and Spotted Pardalote and Rose Robin in 2020.

Alan then outlined what is changing on Broughton and drew some tentative conclusions. The vegetation is changing from grasses to shrubs in sheltered areas and the shrubs are becoming taller with more coastal banksias. There have been two new “resident” species, the Yellow-faced Honeyeater and Little Wattlebird. Four other new arrivals have been Brown Goshawk, Brown Falcon, Golden Whistler and Grey Fantail. There has been an increase in Silvereye numbers and a decline in Golden-headed Cisticola.

The island’s importance to seabirds is growing with Gould’s Petrel visiting regularly and breeding numbers seem likely to expand. White-faced Storm-Petrel may return so expect more of the “unexpected”. Numbers of coastal and waterbirds remain constant as their habitat hasn’t changed greatly. Alan wondered what will happen to the Beach Stone-curlew when the crowds of visitors come back to the island.

There are lots of raptors on the island with two new arrivals, Brown Goshawk and Brown Falcon. Their numbers may be linked to the increase in the number of . There have been four new arrivals of terrestrial birds and an increase in the number of Silvereye. At the same time there has been a decline in some grassland species.

It has been a great achievement for HBOC to be part of this detailed study tracking the changes in the habitat and birdlife of this island. Alan also acknowledges the work of Susanne Callaghan and NPWS, the 25 HBOC members who have helped with this project, Greg Little and his team of banders, Jeff and Mez Pettifer for accommodation and general information and Robyn Stuart for statistics assistance.

Once again this was a thoroughly professional presentation. As much as we appreciate our visiting speakers it is gratifying that our own members can keep us so well-informed about birdlife in our own region.