NOTE: the two photographs towards the end of this have been snipped from a .pdf file and are fell below the quality of the images taken by the photographers, but they still illustrate what is required for the purpose of this post.
NOTES FROM THE HINTERLAND: SAME-SAME, BUT DIFFERENT
In the past few years I have prepared notes for Canberra Bird Notes (Butterfield
2014, 2015) on three topics, covering observations from Carwoola and Bungendore
(to the East of the ACT). This report updates those topics to cover some
observations in 2015-16. Thanks to David McDonald and Garry Moffit for comments
on a draft.
Tawny Frogmouths: presence and breeding
A pair of Tawny Frogmouths (Podargus
strigoides) continued to be present in my GBS site from January 2015
onwards. As expected they constructed a nest in a large Yellow Box (Eucalyptus
meliodora) starting on 21 Aug 2015 – approximately the usual date.
As has been the case for
several years a pair of Pied Currawongs (Strepera graculina) also
constructed a nest in the same tree and displayed aggression every time this
author crossed the lawn. More unexpected was the amount of aggression the pair
displayed to the Frogmouths with the sitting male getting attention many times.
The breeding timetable of the
Frogmouths was complicated this year. From the start of construction to the
male starting to brood was 19 days: 2-3 days longer than usual. After 28 days
(average length of incubation) on 7 Oct the male displayed the agitated
behaviour which in past years has typically indicated that at least one chick
was hatching. It was some days before I saw a chick and I was hoping to count
back from the date of them leaving the nest to confirm the date of hatching.
The Currawongs continued their obnoxious behaviour, causing me to have some
concern for the welfare of the chicks.
Unfortunately we had planned a
trip interstate commencing on 8 Nov on which date the chicks were still in the
nest. When we returned (14 Nov) the nest was empty. The period of our absence
meant that the brooding period could have ranged from 33 days following the day
of agitated behaviour (normal duration) to 37 days (2 days longer than ever
noted in the past). I was unable to locate the family despite carefully
searching each tree in my entire GBS site (the nest tree is approximately in
the centre of the site). This was very unusual as the family tends to stay in
very visible positions in the site for 20 -30 days before vanishing –
anthropomorphising, to show the chicks the boundaries of the parent’s
territory. I have considered the change in behaviour to be an outcome of the
harassment by the currawongs.
There may be two possibilities:
1.
They moved
outside the range of the Currawongs (but within the adults’ territory) on to
adjoining properties which I could not search on a regular and rigorous basis;
and/or
2.
They adopted
roosts in denser foliage (of which there is much) to hide from the marauders
and I just failed to locate them.
When the
adults returned to the GBS site towards the end of January they roosted in a
site they had used very occasionally in the past. The site offers much denser
foliage cover. I also noticed an adult currawong attempting to harass them
despite the currawong chicks having fledged many weeks earlier. These
observations lead me to conclude that option 2 was at least part of the
difficulty of locating the family after fledging.
In March and
April the pair of Frogmouths has adopted its more normal daytime roosts and I
have found them slightly more often than in the past. It is interesting that
the birds have only roosted “snuggled together” for 60% of the days I have
found them this year. In 2015, which I believe to be the old normal, they had
snuggled up on 80% of days. I am tempted to suggest that this change of
behaviour implies that one of the birds is a new partner but in the absence of
bands it is impossible to be sure.
Plumed Whistling ducks at Bungendore
A review of
the records of Plumed Whistling Ducks (Dendrocygna eytoni) in the COG
Area of Interest was published recently (Butterfield 2014). Numbers of birds
have steadily build-up in the flock at the waterbodies close to the village
(now approaching suburb status) of Bungendore from 2009 to September 2014.
Records
submitted to eBird1 for the Bungendore area from Nov 2014
to Jun 2015 show a dramatic increase in the size of the flock in Feb 2015. [i]
From 2 Feb 2105 until 26 Apr more than 70
birds were frequently reported in the flock, with a peak of 102 birds on 2 Feb.
A number of observations of smaller numbers during that period indicates that
the flock moved around and sometimes split up resulting in some observers only
seeing part of it.
The period in
each year in which the birds have been recorded has also extended since the
previous review was published. In 2015 there were still 20-22 birds present
until 23 Jun. There were no records in July, which is now the only month in
which the birds have not been seen in the area.
In spring 2015
the first reappearance was recorded on 6 Aug with 16 birds on the Trucking Yard
Lane dam. A similar number of birds were recorded there or on the nearby Bungendore
Meadow dam over the next 10 days. The sites at which the birds have been found
then extended to include a dam on Burrows Lane (approximately 250m south of the
known site at Bungendore Meadow Dam). The birds were seen here almost
exclusively from 22 Aug until 5 Oct, by which time the flock had increased to
43 birds.
There was then
a gap in reporting from any of the known sites until 5 Nov 2016. Contact was
also made with some local landholders to try to find where the flock had gone,
but no definitive reports were received (in two cases landholders said they had
seen unusual ducks which might have been this species). In a conversation on
June 1 2016 with the owner of the land on which all three dams are located he
stated that the ducks had relocated to another dam on his property which is not
visible from the road. On 5 Nov 2 birds were reported from Bungendore Sewage
Treatment Plant (STP). From then until 9 Dec 1-6 birds were present at one or
other of the three dams to the south of the village. Numbers then jumped with
21 – 35 birds being reported from the STP from 9-12 December.
There is then
a two week gap in reports (possibly reduced observer effort over Christmas) and
the flock of around 35 birds reappeared moving between the three Southern dams.
In February (the latest month for which comprehensive data (ie a download for
all sites) is available from eBird ) the flock has been mainly at Trucking Yard
Lane and continued at 35 birds. At the individual hotspot level there are
several records of 20 – 30 birds of this species at Trucking Yard Lane in March
and April 2016 as well as several records not including the species.
The flock
sizes reported to eBird are summarised in the scatterplot ‘Plumed Whistling
Ducks in the Bungendore area’
I believe
observer effort has been reasonably consistent with previous years and that for
some reason the birds have not arrived in this area in the large numbers
reported in Feb – Apr 2015. It is tempting to ascribe this to the relatively
hot and dry summer but:
1.
My
rainfall records have given an overall average amount of rainfall since Oct
2015; and
2.
Pastoralist
friends in the local area have commented on their livestock doing well despite
the apparently dry weather conditions.
Examining
Bureau of Meteorology climate data suggests that my records are very broadly
consistent with rainfall records from Wagga Wagga, Cootamundra and Deniliquin.
I am therefore reluctant to link the reduction in the birds arriving here to
short term local variations in rainfall. However I have noted a comment in an
ABC article2[ii] that there have been severe water restrictions (for rice
irrigation) in the Deniliquin area leading to reduced rice production. Possibly
this has had an impact on breeding or bird survival in that area leading to
lower numbers being available to come to Bungendore?
Whatever the
answer to that question, it is clear that our understanding of where the birds
are located while they are in this area still has some gaps. It is also unclear
why they choose to stay at a site for several days or weeks and then move to
another site: when viewed at Trucking Yard Lane they appear not to be disturbed
unduly by observers on foot within 20m and rarely react at all to the movements
of cattle into or around the dams. It has been suggested that their presence at
Trucking Yard Lane is correlated with local rainfall: that has not yet been
investigated but will be the subject of further research.
Banded Lapwings at Hoskinstown
In a recent
review of the records I have maintained for the Carwoola area since moving here
in 2007 (Butterfield 2015) I commented on the observation of large numbers (up
to 45) of Banded Lapwings (Vanellus tricolor) feeding in an oats paddock
on the Hoskinstown Plain in Oct 2012 – Mar 2013. As the management of the
property on which these sightings were made has been quite consistent from year
to year it has been somewhat surprising that the birds have not been sighted
there since.
It was even
more surprising to read a COG chatline report of 11 Banded Lapwings on 20 Jul
2015 in a paddock beside Hoskinstown Rd, approximately 2.5 km from the previous
site. Many COG members visited the site over the next few days causing some
interest amongst local residents. (The land owner did notice the activity but,
as people were very responsible in respecting his property, was not concerned[iii].) Over the next few months the birds
ranged over an area of approximately 10 hectares[iv] including a marshy area beside the road and a dam.
Although the
number of birds sighted varies somewhat I believe this simply reflects the
propensity of the birds to wander across the site and, when sitting, to be
hidden by - or indeed mistaken for - one of the many cattle droppings. If the
lapwings were over the lip of the dam they were totally hidden from view from
the road.
An image by Christine Darwood, shared on
the chatline5, was taken of birds copulating on 16
Aug 2015.
While many
reports were given, both on the chatline and in personal conversation, of birds
appearing to be sitting on eggs this behaviour was not consistent and the birds
could never be relocated, in the positions described, on follow-up visits.
However a chick was sighted on the morning of 16 Oct 2015 by a local observer,
and reported to eBird on his behalf by this author.
Twelve birds
were sighted by this author in the afternoon of 16 Oct after being flushed –
probably by a raptor but I was looking at the grass in an effort to relocate
the chick and only alerted to the disturbance by the alarmed calls of the
flying birds. Six Banded Lapwings were still present on 31 Oct 2015. The following image of a flying Banded Lapwing has been snipped from a photograph by Julian Robinson
As a
consequence of the good rains in November the grass grew quite tall in the area
from the start of that month onwards. As a result, if the birds were there,
they could not be seen from the edge of the paddock (and despite permission to
visit from the landowner this observer did not fancy sharing the area with a
small, but potentially frisky, bull). Since most references to the preferred
habitat of the species (Marchant and Higgins, 1993) refer to short grassland it
may be that they did not find the taller grass suitable. However it was notable
that at the previous visit of the birds the oats crop in which they spent most
of their time was of such a height that often only the heads of the lapwings
were visible above the crop. This had introduced a rather sporting element to
counting the numbers present.
It will be
interesting to see if the birds return again in future years. I was aware of a
single historical report to the Atlas of NSW Wildlife of this species from an
area close to the Molonglo (on the opposite side of the Plain about 6 km from
the Hoskinstown site, but had regarded that as an identification error. They
are known from Lake Bathurst (approximately 45 km from Hoskinstown) but are
also not present in every year there (M. Lenz pers. comm.). I am now
inclined to regard the species as an irregular breeding visitor to the Carwoola
area. (And will look very carefully at all members of the genus Vanellus seen
in the area from now on.)
References
Butterfield,
M. A. (2014) Plumed Whistling Ducks in the COG Area of Interest. Canberra
Bird Notes 39: 173-184.
Butterfield,
M. A. (2015) Birds of “Carwoola”. Canberra Bird Notes 40: 132-146.
Marchant, S.
and Higgins, P J (eds) (1993) Handbook of Australian, New Zealand and
Antarctic Birds, Vol 2, Melbourne, Oxford University Press.
[i] As a high
proportion of records submitted to COG come from eBird and most of the regular
observers at Bungendore use that system I didn’t invest further time necessary
to access any remaining records.
[ii] http://www.abc.net.au/news/2016-01-20/pooling-water-rice-crops-nsw/7100862
[iii] This contrasts with reports on birding-aus of birders
trespassing to observe a Paradise Shelduck.
[iv] Area assessed using the polygon feature of Google
Earth Pro
[i] As a high
proportion of records submitted to COG come from eBird and most of the regular
observers at Bungendore use that system I didn’t invest further time necessary
to access any remaining records.
[ii] http://www.abc.net.au/news/2016-01-20/pooling-water-rice-crops-nsw/7100862
[iii] This contrasts with reports on birding-aus of birders
trespassing to observe a Paradise Shelduck.
[iv] Area assessed using the polygon feature of Google
Earth Pro
