… John Newman and Craig Morley

A fairly gripping winter to date has not slowed down the bird observers of Geelong and surrounds. Many people have been out despite regular rain, very cold frosty mornings and a good amount of wind. Accordingly our local birders have recorded many great observations of our winter birds and in many cases made detailed records of their behaviour.

Several of the regular winter surveys have occurred this month and being focussed on shorebirds, waterbirds and saltmarsh parrots we not surprisingly have had good records of wetland birds from right across the district. It has been very interesting to see regular records over many years of breeding Black Swans at Breamlea and they’re ‘back in the news’ this month with cygnets. A high number of swans (829) at Lake Victoria are utilising the conditions with a few attending to nest renovations in preparation for breeding.  Eight Brolgas at Sparrovale were a delight and a trio including an immature at Reedy Lake, seen a little later the same day, were possibly from that same group. A large flock of 156 Cattle Egrets has been seen in a paddock without stock along Murradoc Road at Drysdale. Keep your eyes open for other flocks around our area and continue to inform us of their local preferences and habits. Similarly a total of 116 Royal Spoonbills at Swan Bay west including at least 90 roosting near the jetty with a few Yellow-billed Spoonbills, complemented a large flock of Royal Spoonbills in the same area several weeks earlier. A small flock of Australasian Shovelers at Freshwater Lake was a good find, as they materialised amongst myriad teal, included an immature bird.

A solitary Banded Lapwing alerting observers with the characteristic metallic strident call, was an unexpected thrill, at Lake Connewarre and good numbers of Black-fronted Dotterels at Moolap Saltworks, during a complete survey of the site, likely indicative of ponds inundated with stormwater from adjacent areas. A very large flock of 55 Red-capped Plovers at Eurack seemed to be making the most of a hypersaline pond and food reserves.

We have once more enjoyed numerous reports of Australian Hobbies, particularly in fading light at or near sunset indulging in crepuscular hunting. Breeding of Black-shouldered Kites through autumn and into winter certainly seems to be a regular occurrence locally – this month numerous reports of young birds with adults have been submitted from Lake Connewarre, Sparrovale, Point Henry and Balliang. A wonderful observation of six Wedge-tailed Eagles at Balliang was stunning with the observer noting four birds standing in a paddock and two perched in adjacent trees. Two great records of White-bellied Sea-Eagles this month detailed a pair at Lake Connewarre participating in a honking duet and a single immature bird catching a fish in the shallows of Stingaree Bay offshore from Moolap Saltworks, not a common bird here at all. Several Barn Owl records from Werribee and Balliang prove the benefits of going looking along rural roads after dark on a winter’s night.

An Australian Reed Warbler calling regularly was an unexpected winter record for Reedy Lake and a Brush Bronzewing on a track at Bellbrae was a great record of a moderately common, though infrequently observed species in our region. A Crested Shrike-tit in direct-seeded revegetation in Colac was satisfying as were Flame Robins at Wallington, Reedy Lake and Mt Gellibrand. A flock of 12 Gang-gang Cockatoos along the Barwon River in Newtown and a Laughing Kookaburra at Grasstree Park at Torquay and two birds calling in suburban Highton made for pleasing records. Mistletoebirds are still around enjoying the fruiting mistletoe at Edwards Point and a Rose Robin in Bellbrae brought a smile to the observers. The same observers noted two green Satin Bowerbirds looking for olives to eat at Bellbrae.

An enormous count of more than 2800 Welcome Swallows at Sparrovale appeared as clouds of birds and another super-flock of Yellow-tailed Black-Cockatoos, some 170 birds, were seen at Highton and this record was complemented by many other records of large flocks around town.

Once more we extend sincere thanks to the keen observers and chroniclers of our birds who consistently add their records to the club web-site or as complete list or incidentals to eBird.

Please look for the full list of recent records at https://www.gfnc.org.au/observations/bird-observations and at eBird Australia https://ebird.org/australia/explore and remember to log-in to take full advantage of the wonderful options this website has to offer.

Shield Shrimp

by Ade Foster

shield

The Tadpole or Shield shrimps belong to the Class Crustacea, in the sub-class Branchiopoda (gill-legged), and the order Notostraca. (flat-back) There are two genera world-wide, Triops and Lepidura, each represented by a single species in Australia, T. australiensis australiensis and L. apus viridis.

The most prominent and easily recognisable feature is the dorsal carapace or shield which covers the majority of the animal. It is attached at the front only, and can be lifted clear of the body. There are a pair of sessile (fixed) compound eyes at the front of the shield. The body itself is made up of a large and variable number of segments or body-rings, numbering up to 70. The last segment has a pair of caudal rami or tails and inLepidurus a supra-anal plate which is not found in Triops. The first eleven segments make up the thorax, and each bears a pair of foliaceous (leaf-like) appendages called phyllopods, the last of these bear the ovisacs. These legs are beaten back and forward and propel the animal very quickly through the water, and also act as the breathing apparatus. The number of legs behind the thorax varies greatly, and may be up to sixty. It is peculiar to Notostraca that each segment may bear more than one pair of legs. There are a number of the hind most segments are free of legs, forming a long and very mobile tail.

Notostraca have been found in a variety of habitats including temporary rain-pools, slightly salty lakes, freshwater lakes, farm dams, drainage ditches and the like. They are never associated with marine, saline or estuarine environments. They seem to be most commonly associated with freshwater habitats which dry up periodically, and in one species at least, it is necessary for the eggs to undergo a period of desiccation before they will develop. In all species, eggs are very resistant to long periods of dry conditions.

Notostraca are found on all continents except Antarctica, and in most climates where ephemeral pools occur. In Australia they are found wherever there is suitable habitat. In the North and the drier inland areas, only Triops is found. It hatches at any time of year, given suitable pools of water. In the Southeast, where both Triops and Lepidurus occur the adults have only been recorded in winter and early spring. The range of the two species is mostly distinct, with some overlap in NSW and N. Victoria.

Populations from around the world vary greatly in the manner of their breeding. There appear to be males and females in most populations, although all individuals are to some degree hermaphrodite. Parthenogenesis exists in some populations, but they cannot self fertilise. In Northern Europe and the USA males occur rarely, with populations being female or hermaphrodite. In warmer climes the sexes are balanced. Eggs are carried in the egg sac until mature then laid in the silt at the bottom of the pool. Some hatch immediately, others form oocytes and remain in the soil after the pool dries, remaining viable for periods of up to ten years without water. The microscopic young grow quickly and after several moults resemble the adult. This rapid growth may take as little as twenty four hours. Eggs appear after seven days and shrimps are fully mature at three weeks. Desiccated eggs begin to hatch within three days of the pools filling again.

Shield shrimp filter feed on microscopic animals in the mud at the bottom of a pool, may catch small animals or graze on water plants. Even cannibalism of recently moulted fellows has been reported. The phyllopods have a channel between them and the beating forms a current which carries the food animals or particles to the mouth.

Several members told me that these creatures were common in their youth, but not seen so often now. Could this be a product of our environment, or just that as we get older, we don’t have as much time to play around in puddles?

In a spin:

To be resupinate or not to be resupinate that is the question. Well, that must have been the problem facing orchids as they evolved. You know I said sun orchids (have you seen some ?), were resupinate. This means if you compare an orchid flower with another flower, such as the Early Nancy, the orchid flower appears to be upside down. In fact in its development the orchid flower turns through 180 degrees. But then you get the Leek Orchid which is non-resupinate which appears to be upside down but is really the right way up. It has left out the 180 degree bit. Having written all of that I am thoroughly confused and no doubt you are too. Leek Orchids are common enough but don't grow in great numbers except after summer bush fires. They seem to prefer moist habitats so keep that in mind when looking. We found two Austral Leek Orchids (to be confirmed) close to Butchers Road in the Brisbane Ranges, with flowers made special by their crystalline white labellums. Look for a tall orchid with a flower stem of up to 90 cm. emerging from a single rounded leaf like that of a leak or onion. There are at least six species of Leek Orchids found around Anglesea or the Brisbane Ranges. To the untrained eyes, yours and mine, they all look the same.

         Caladenia      Leek Orchid

                       Caladenia Orchid                                   Leek Orchid         (photos: D.Hewish)                              

                                                Joe Hubbard died in October 2015