A few odd observations.

Last week I took a small group of bushwalkers (2 locals, and 2 American visitors) for a stroll along the Boxvale Track, near Welby (south-western edge of Mittagong), in the Southern Highlands of NSW.

The track is classed as an historic attraction, as it follows the line of an old railway line which was built to service the Box Vale Coal Mine which entered the coal seam halfway down the steep gully overlooking the Nattai Gorge. That way, they did not need to dig down through the overburden, but rather could cut straight into the open side of the coal seam (exposed by erosion of the hillside by the action of the river).

We were there to look for birds, which were moderately abundant.
I did not take any photos of birds on the day, as my task was more to listen and identify bird calls and then point out where the culprits might be seen.
Throughout this post, I will link to the Photo Gallery of the Canberra Ornithologists Group. The individual photographers are credited by that site. For the Rockwarbler, I have linked to the Birds in Backyards site, as it gives a full life history for that bird.

Some, such as White-throated Treecreepers and Fan-tailed Cuckoo were nice and obliging.

Black-faced Cuckoo-Shrikes perched high on Eucalypt Trees, and shuffled their wings, co-operatively. Rufous Whistlers were abundant. We heard Yellow-tailed Black Cockatoos in the distance, but they did not fly close to us, unfortunately.

We went up to the side of the old Water Reservoir (on the Nattai Creek). This is a good reservoir for water birds.
We saw:

• Australasian Grebes (several on floating nests)
  
• Pacific Black Duck
• Australian Wood Duck
• Little Pied Cormorant
• Great (Black) Cormorant
• Australasian Shoveller (a surprise for me)
• Royal Spoonbill in breeding plumage
• Eurasian Coot
• Dusky Moorhen
• Australian Reed-Warblers (calling profusely from the reeds beside us).

After we left the dam, we went up a steep part of the track (the railway line obviously crossed the creek on a very tall wooden bridge. The footings of the bridge posts are still visible.) As we walked up away form the creek we saw a bird which I was not expecting to find - a Rockwarbler, or Origma (image). I was provoked to lapse into the vernacular, and comment that these birds are "as rare as Rocking-horse Shit". In fact, the habitat is classic for this species, which is almost exclusively confined to "Sydney Sandstone" and adjacent limestone habitats. Normally if I see them, I expect it to be near the local waterfalls and cliffs, not just beside a walking track, even though we were close to the local sandstone creek gully. These birds are really fond of steep clifflines.

We continued along the track, which, as the train line crossed creeks or dips in the terrain, is raised some 5 metres above the surrounding natural strata. To get through the hilly ridges, the track was excavated through solid sandstone rock. The best example is the "Casuarina Cutting" which is nearly 10 metres deep, for a distance of over 250 metres. It is fascinating in this narrow cutting, to observe the tree roots which have been exposed by the excavation. Tree roots growing through rocks, following the water which penetrates along the natural crevices in the rocks.
In several places there were signs of previous fires, and the Lomatia silaifolia were flowering heavily, with their creamy white flowers. These plants tend to flower freely one season after a fire.
There are some magnificent old Scribbly Gums on the tracks in this area. Old trees with huge hollows, which must suit Owls, the Black Cockatoos and Possums. These are true "habitat trees" - whose continued existence is critical to the fauna of the region, as well as being old "seed trees".
Along the lower track which we followed back to the carpark, (we turned right, off the Forty Foot Falls track, after about 500 metres and went back parallel to the main track) there are many specimens of Persoonia glaucescens - the "Mittagong Geebung". It is always great to find an endemic species growing freely in the area after which it is named (Mittagong). This plant has a very localised distribution, and is listed on both Federal (EPBC Act) and State Threatened Species lists.

I thoroughly recommend the Boxvale Track walk, as there is always something interesting to see along this track - whether it be of historical interest, plants (it is especially good for Waratahs, in season), or for rare and/or uncommon birds.