Silvereyes feeding on lerp

On a recent BirdLife East Gippsland Monday morning outing to Log Crossing in the Colquhoun Forest near Lakes Entrance a few of us came upon about six Silvereyes feeding on the common reed (Phragmities Australis) growing beside Mississippi Creek. The birds were very intent on gleaning something from the underside of the large leaves. 

Silvereyes have a broad diet including fruit, seeds, insects and nectar. We were intrigued to know exactly what these birds were feeding on which was not obvious as the birds were foraging on the underside of the leaves which were not visible to us.

After taking some photos we checked the underside of the Phragmities leaves and found large amounts of the telltale white sugary coating commonly called lerp (1). Under the coating we found small – not much larger than a pin head – green psyllid bugs (or their larvae?) which make the starchy protective coating. We could not tell if the Silvereyes were eating the sugar rich coating, the larvae or both. I suspect both, given both fit within the known diet of Silvereyes – a rich food source containing proteins and sugar.

Checking the photos later at home on my laptop I could see fragments of the white sugary coating on the bird’s bills and in one case, its back. Also one photo captured some of the lerp on the leaves. An indication of the value of this food source may have been displayed by an altercation between two birds over feeding access to a reed stem – see photo below.

Please click on photos to enlarge.

Note lerp on the tip of bill and the back in the next photo.

The white lerp is visible in the following photo. There were larger pieces forming protective coatings over psyllid bugs on the underside of many of the leaves.

The bird in the following photo is picking lerp off the underside of a leaf – a fragment of lerp is visible on its back.

A feeding area dispute.

There are about nine subspecies of Silvereye across their range in Australia. The birds we found were Zosterops lateralis lateralis (note the rich brown flanks), the Tasmanian sub species, many of which make seasonal migrations across Bass Strait to winter on the mainland. 

Note (1) The word lerp comes from the Wemba Wemba lerep. Lerps are a traditional food source for Indigenous people. 

Australian Hobby

The Australian Hobby(1) (Little Falcon) Falco longipennis can be found in many types of open habitat across Australia including Tasmania. This species has a well-earned reputation for being aggressive. The following description of the bird from my 1959 edition of Neville Cayley’s What Bird Is That (my first bird book), while perhaps somewhat anthropomorphic, captures the character of the Hobby, “It is more courageous in disposition and stronger on the wing in proportion to its size than any other Australian Hawk.”

The Hobby, a mostly solitary bird, can be found perching, but from my experience it is often sighted when engaged in high speed hunting forays. Hobbies capture aerial prey, mostly small birds and they also hawk insects and even take micro bats on or after dark.

While birding beside the Warrego River on the Riverwalk at Cunnamulla in outback Queensland, alarm calls from a number of small birds made me look for the cause which I knew would be a raptor. I soon spotted an Australian Hobby flying very fast along the treed riparian strip and out onto the open flood plain. The Hobby was clearly attempting to flush small bird prey.  However with no success the bird luckily ended its high energy run in a tree near where I was standing – birding and bird photography involves a significant amount of luck. 

I gave the bird a few minutes to settle and then moved a little closer for some photos. The Hobby moved position in the tree once and while it kept an eye on me it seemed comfortable with my presence. The light made photo exposure tricky as the bird was resting in deep shade with a bright sky background. After taking some photos I walked away leaving the Hobby to rest and recover its energy for another high speed hunting run.

 

Please click on photos to enlarge.

Note the long talons – good for catching aerial prey such as small birds and insects.

The long flight feathers extend to the end of the tail – its species name longipennis means long wing. 

The rather large eyes are no doubt helpful in low light – this falcon in known to hunt at dusk and after dark when micro bats are taken.

(1) The name Hobby … was adopted in Australia only recently and applied to this bird, long known simply as Little Falcon, because of its similarity to the Eurasian Hobby, refer Fraser and Gray, Australian Bird Names a Complete Guide, page 80.