Main Club Excursion 14th – 16th May 2021
Yunderup Nature Observatory
Did you know the WA Naturalists’ Club owns the Yunderup Nature Observatory on Cooleenup Island on the Murray River delta of the Peel Inlet? It was built by club members on land vested in the Club in trust as a field station and was opened in 1985. In subsequent years, Club members surveyed the area, recording fauna (birds, mammals, frogs, reptiles and arthropods) and flora (including fungi). The latest survey on 14–16 May was led by Jolanda Keeble and attended by 12 members who either stayed overnight or just came for the day. Transport to the island from the South Yunderup Jetty was by Roman and Lucy Mandyczewsky, the Observatory caretakers.
The island is low lying with Casuarina obesa fringing the branches of the Murray River, and Eucalyptus rudis on the slightly higher ground. There are many ephemeral lakes fringed by samphires. We conducted opportunistic surveys from the Observatory to Coopers Mill to the west, as well as to the east and north of the island. We recorded 53 plants even though only a few were flowering, well short of the 269 recorded by Penny Hussey, Dorothy Anderson, and Shirley Loney in 1997–2000. There were some E. rudis flowering, and a few Lobelia anceps; however, a survey in spring would capture the orchids and ephemerals. The most unwelcome record was of Bridal Creeper (Asparagus asparagoides) on the north side of the island. There were a few fungi about, mainly ones growing on wood. The scarlet bracket, Trametes Coccinea [Pycnoporus coccineus] was abundant on fallen paperbark and the Lavender-pored Bracket (Phaeotrametes decipiens) was common on dead C. obesa. The largest fungus was a White Punk (Laetiporus portentosus) on E. rudis.
Forty different birds were seen. These included water birds such Black, Little Black and Pied Cormorant, Black Duck, Darter, White-billed Spoonbill, Great Egret and White-faced Heron. And there were bush birds too: Bronzewing Pigeon, Gerygone, Grey Fantail, Golden Whistler, Red-capped Parrot, Splendid Wren, and Willie Wagtail. Two raptors, Osprey and White-bellied Sea Eagle were also seen. Other vertebrates noted were dolphin and Western Grey Kangaroo. We saw a number of invertebrates both during the day and when spotlighting. There were 13 different spiders and 11 insects, including the Wood White butterfly on flowers at the top of a Eucalyptus rudis.
The full species list is available from the WA Naturalists’ Club office. Pictures of many of the plants and animals have been uploaded to iNaturalist and can be viewed (without a login)
It was a very enjoyable weekend; the weather was good, and the mozzies were friendly.