Bird of the Week: Striated Fieldwren (Calamanthus fuliginosis)

Image by Lynley-Keene David-Shanahan

This species is in the Family Acanthizidae which includes Scrubwrens, Gerygones and Thornbills: basically the "small brown birds".  From "Australian Bird Names" by Ian Fraser and Jeannie Gray the family name translates from Greek roots to mean 'Thorn-bush dwellers' which seems to a fair description of the habitat of the species.

Ian comments that the original English name for the genus of Fieldwrens, coined by John Gould in 1848 was Reed-Lark possibly linking to an old genus name Anthus for pipit, which is possibly close enough to lark?  From the call I heard in my recent observation of the species covered by this post (see below), I can attest to the lark-like quality of the song.  The current scientific name for the genus of Fieldwrens - Calamanthus - again links to "pipit" and the Greek word kalame for stubble.  The specific name fuliginosis means 'sooty', apparently referring to the dark striations, but as Jeannie says "the overall impression is hardly all that 'sooty'"

Habitat

According to the Australian Bird Guide it is common in low dense vegetation  such as low dense heath, sedges and and tussock grasslands.  Basically a very good description of the area between the Mallacoota airfield and the Gun Club where I observed it.  In an excellent Avithera blogpost, John Hutchison describes the samphire habitat in he which observed and photographed the species.

The Gun Club area was slashed to meet safety requirements of the airfield and was then completely burnt on 31 December 2019 as the wildfire crossed the area.  The vegetation regrew through 2020 with an outstanding orchid display in Spring 2020.  Since then grass and sedge species have regrown to thigh height with some shrubs emerging.  (During the Big Weekend 2021 one observer who visited the area described it as "perfect Southern Emuwren habitat".)

When I compiled a review of the initial impact of the fire I included Striated Fieldwren as one of the Heathland specialists covered in a case study.

Locations

The species maps below were extracted from eBird and Birdata.  22 of the 43 eBird records relate to observers having loaded their historical records and only 5 of the Birdata records are post 2014.

The orange pin is my sighting from 27 April at the Gun Club.  I was initially surprised that there were no eBird records from Howe Flat.  However the wetland edges and flats are better habitat for fieldwrens compared with the shrubby areas that hold most of the Bristlebirds (the usual target for birders going to the Flat) and it is suspected only a small proportion of visitors to Howe Flat get to those wetland sites.

There are no Birdata sightings from the Hinterland, but there is a record from Howe Flat in 2009!  The site is labelled as the track, rather than the Flat proper, and the marker is placed close to a wetland area.

Identification

Like most members of the genus this species is a skulker.  Quoting from The  Australian Bird Guide (ABG)  "Otherwise unobtrusive, foraging on the ground ... skulking in vegetation often to near top of shrub to keep an eye on intruding birdwatchers."  An exact description of my recent sighting and well illustrated in the next two images.

Image from Avithera by John Hutchison

Image by Craig Boase

The features listed in ABG are olive above, yellowish below and boldly streaked blackish (sooty?) throughout.  The long cocked tail is distinctive.  

In my sighting I was very struck by the olive colouring on the back: I felt it much more obvious than the colours in ABG, HANZAB, Slater x 3, or the Pizzey and Knight app.  These images capture more of the olive colouring.

Image from Avithera by John Hutchison

Image by Lynley-Keene David-Shanahan

A Xeno canto recording (XC608820, by Marc Anderson, second in the linked list) gives an excellent rendition of the call which attracted my attention.  With the assistance of Google Earth I estimate the bird was 150m away but the call was very clear in quite still air.  I was only able to see the bird at that range thanks to having my telescope set up (searching, unsuccessfully, for Emuwrens) and would possibly never have seen it had it been silent.  ABG notes that it sings year round and is more often heard than seen.

Other Notes

In a report published in Canberra Bird Notes giving my initial thoughts about the impact of the 2019-20 fire on birds in this area I concluded with a case study of Heathland specialist birds, of which I consider this species to be an example.  I said:

"A positive outcome is that only one of the specialist species (Striated Fieldwren) has not been reported at least once in 2020: but there are low numbers of reports of this species (at best) in most years. Add to that the reports of Eastern Ground Parrot and Southern Emuwren since June and the picture looks less bleak than it might have done."

With my sighting of 27 April we have the final specialist bird re-sighted.  Indeed a less bleak outlook.

Reporting rate x month

The monthly pattern shown by the eBird reporting rate (# records of Striated Fieldwren/number of lists) is interesting, but possibly says more about birders not liking cold weather than bird distribution. Given the behaviour of the bird the rate suggests that there are a small number of birds around throughout the year.  The low rate for September is puzzling, as it could be expected that the birds would be in full voice by then.

A chart of number of  sightings per month from Birdata probably reveals that Birdata observers come to Mallacoota more in Summer and Autumn than Spring!  I don't have access to the number of lists per month to calculate a rate.

Observations x Year

I have been able to combine the number of observations per year from the Birdata species account and the eBird records for 'my' Mallacoota District. 

I suspect the high value for 1988 reflects extra visits due to a specific project (its a year too early for the second Bird Atlas to have an impact).  While it is tempting to explain the high values from 2014 -16 as being enthusiasm from the introduction of eBird this does not explain the subsequent drop.  The total absence of records in 2020 is intriguing: while the heaths were burnt out they did have growth by the end of the year, and birders were revisiting most of the areas.  My recent sighting from the Gun Club suggests the species was around the area generally but not detected.  Perhaps the birds found refuge in unburnt and unvisited areas nearby?

Acknowledgements 

Thanks to Lynley-Keene David-Shanahan, John Hutchison and Craig Boase for images and to Rohan Clarke and Tim Dolby for advice about Howe Flat,