Friday 11 October 2013

Brood of three

The male Tawny Frogmouth covers the chicks during the day
The pair of  Tawny Frogmouths which nested earliest in my study area in Canberra now have three well-grown chicks, about three weeks old.

I recorded their activity remotely last night on a Bushnell trap-camera set on an adjacent branch, and they seem to be bringing in moths to the chicks. Certainly small wingless tubular bodies and one very small frog. There are lots of Bogong moths Agrostis infusa in Canberra at the moment as they migrate from their breeding grounds to the hills south of the area. So there is plenty food for all five birds.

Click on this link if you would like to see footage of the three chicks jiggling for space on the nest.

Thursday 3 October 2013

A local speciality

Black Mountain Leopard Orchid Diuris nigromontana 

The orchid flowering season is now well on the way with several local species in bloom. There are over sixty varieties in the dry schlerophyl forest on Black Mountain, in the centre of Canberra, and this one is special. For it grows nowhere else in the world but in the area around Black Mountain. It stands about twenty centimetres tall, growing between tufts of grass and shrubs, and I have seen several little colonies in the past few days. The rich yolky yellow is quite obvious among the dull grey grass stems.

Wednesday 2 October 2013

Butcherbirds

Adult male Pied Butcherbird - there is a reason for the glove, see below
Last weekend I was on a bird-banding trip to the Weddin Mountains, run by Richard Allen. There were seven of us altogether to set up and maintain vigilance over the numerous mist nets we had placed throughout a patch of wooded, partially-cleared pastureland adjacent to the nature reserve. Most of the birds in the area seemed to be local breeders, which was reflected by the catch of adult birds of a wide variety of species, but no high numbers of any one species other than White-plumed Honeyeater, which were abundant and breeding. One pair had a nest in the tree branches above the banding station. And we also found nests Spotted Pardalote, Speckled Warbler, White-winged Chough and Pied Currawong. 

The glossy black hood and wide white collar indicate that this is an adult male bird,
some of the bird's black feathers have faded to brown under almost
 a year of sunlight since it probably moulted and grew that set  
Butcherbirds are never abundant in any area as the pairs guard their territories well, excluding all others. So it was doubly opportunistic for us to catch two species, Pied Butcherbird Cracticus nigrogularis and Grey Butcherbird Cracticus torquatus. And as they were breeding, we had a chance to compare and note features of the two species' full adult plumage. The Pied Butcherbird illustrated here is an adult male, the distinguishing features for an adult being: the blue-grey bill with a black tip, juvenile and  immature birds have grey/brown bills through to dull blue, each with a dark grey tip; his hood is black rather than brown/grey of an immature bird. Adult females have less white on the outer wing coverts, less glossy black in the hood and grey on the back. 

Butcherbirds have a well defined hook on their bill tip
The Grey Butcherbird is very like the Pied and could perhaps be most quickly described as a similar bird, but of of duller plumage. As its name describes, it is grey overall. The adult male has a black hood, but white throat unlike the Pied's black bib. As with the Pieds, these adults also have blue bills with black tips, while the young birds have grey-brown ones with darker tips. The bird illustrated here is an adult female as she has a grey-brown hood and a distinct patch of off-white feathers in the lores, complete between the eye and bill; the male has a distinct white spot on the lores which does not extend to the eye.  

Adult female Grey Butcherbird
Great care should be taken when handling butcherbirds of any species as they can bite...

The hook on the tip of a butcherbird's bill is well adapted for gripping

Tuesday 1 October 2013

Orchids

A cluster of Green-comb Spider Orchids
While mist-netting birds at the weekend, out at the Weddin Mountains, NSW, we found ourselves walking through  woodland understorey grassland, with numerous orchids in the sward. The first species I noticed was the Green-comb Spider Orchid Caladenia tentaculata which was growing in small groups of several flower spikes in several locations. All the flowers looked fresh and newly opened.  

A jewel in the grass
Other species which were frequent if not quite abundant included Purplish Bearded Orchid Calochilus robertsonii (Below), Blue Fingers Cyanicula caerulea, a species of greenhood and one or two species of sun orchid Thelymitra. I was too busy catching and banding birds to take enough photographs of all the species, so I grabbed what images I could on passing and sent them to Denis Wilson who kindly helped to identify them. He has some great illustrations on his own blog at  http://www.peonyden.blogspot.com.au/ .


A spectacular little flower

Thursday 26 September 2013

Buff-rumped Thornbill nest

A well hidden thornbill nest
The woods are busy with the sound of nesting birds at the moment. Some building, carrying material, some scolding in alarm as we pass by and others make almost constant contact calls between one another as they gather food for chicks. Chicks which lie still in hidden nests, but can blow their cover by emitting urgent begging calls as they see or hear their parents approach with food.

This nest is of a pair of Buff-rumped Thornbills  Acanthiza reguloides. It is a neatly crafted ball of bark strips and grasses locked together with spider webs and egg cases, then lined with what looked like a mix of small feathers, kangaroo hair and plant down. Set in a crack behind some flaking bark on an old Yellow Box tree it was invisible from most angles, except from that from where the side entrance could be discerned as a tell-tale round hole in an otherwise linear pattern of bark. 

I heard the adult birds first, calling to one another, then they gave alarm as I approached their nest tree. I could see they were carrying food; a large moth in the first case, the other something very small, so I walked back a few paces and watched the birds sneak into their nest to feed their chicks (3). They quickly set off for another foraging trip, and I knew I had about two minutes before they returned. So I unzipped the camera as I approached the tree, found the nest straight away, took a few shots, and walked away before the birds returned. Minimal disturbance, means minimal risk of predation by ravens or currawongs.

Small birds only need small niches to nest in - some very small