yellow throat - birdlife
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YELLOW THROAT The newsletter of BirdLife Tasmania: a branch of BirdLife
Australia Number 107, Spring 2019
General Meeting Thursday, 12 September, 7.30 pm
This month’s presentation is by James Pay: Investigating the conservation requirements of the
Tasmanian wedge-tailed eagle (Aquila audax fleayi).
James has focused his research towards the behavioural ecology of birds. After completing his
undergraduate degree in zoology at Aberystwyth University, he worked as a research assistant with
the Royal Society for the Protection Birds and the Centre National de la Recherche Scientifique
investigating foraging and breeding behaviour of both endangered and common bird species
throughout Europe. His work in animal behaviour has led to an interest in how ethological studies
can aid in guiding the conservation management of threatened bird populations.
Abstract: The overarching goal of James’ PhD research was to inform the conservation management
of the endangered Tasmanian Wedge-tailed Eagle (Aquila audax fleayi). Prior to this study,
conservation efforts had focussed on the threats of breeding habitat loss and disturbance to nesting
eagles, but little is known about the habitat requirements of other life stages, or the extent of other
threats that may impact survival. Using GPS tracking, James investigated the behaviour and habitat
associations of 25 juvenile Tasmanian Wedge-tailed Eagles. This data was used to develop models
that predicted where different behaviours are likely to occur in the Tasmanian landscape.
In addition… Using
data from Birdata
surveys, Warren Jones
will show the differences
in bird utilisation of the
different forest types in
the Peter Murrell
Reserves.
Meeting venue: Life
Sciences Lecture Theatre
1, Life Sciences
Building, University of
Tasmania, Sandy Bay.
Access and parking are
from College Road or
from the parking area
outside the University
Centre via the pedestrian
bridge over Churchill
Ave. Everyone is
welcome to stay for tea
and coffee afterwards.
Fan-tailed Cuckoo. Photo by Michelle Turner.
Spotted Pardalote at Peter Murrell. Photo by Sue Jones.
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Yellow Throat is now issued quarterly. Each month, BirdLife Tasmania is producing an e-
bulletin, Tasmanian Branch e-news, which goes out to members and supporters. Every third month it
is dedicated to distributing Yellow Throat electronically, while in other months it will contain events,
short articles, news, volunteer opportunities and, of course, wonderful photographs.
In this issue of Yellow Throat General Meeting Thursday, 12 September, 7.30 pm ........................................................................... 1
Black Swans – Graceful Waterfowl or Vermin? ................................................................................. 2
Revisiting the Bird and the Blade ........................................................................................................ 4
What’s happening in my patch? ........................................................................................................... 8
In the foothills of kunanyi ................................................................................................................ 8
BirdBanding NW Tasmania ................................................................................................................. 9
Pallid Cuckoos ................................................................................................................................... 10
Will this be a Shining Bronze-Cuckoo season? ................................................................................. 11
Eyes bigger than stomach? ................................................................................................................. 13
BirdLife Tasmania news and views ................................................................................................... 14
Australian Bird Environment Fund (ABEF) grant ......................................................................... 14
Draft Tasman National Park Fly Neighbourly Advice (FNA) ....................................................... 14
Listing of threatened species and communities ............................................................................. 15
Southern excursions ....................................................................................................................... 15
North-west walks and talks ............................................................................................................ 15
Twitchathon 2019 .......................................................................................................................... 15
Opportunities for involvement ....................................................................................................... 16
November BirdLife Tasmania General Meeting ........................................................................... 16
Black Swans – Graceful Waterfowl or Vermin? By Ralph Cooper
Two events promoted an investigation into the slaughter of swans on farmland bordering the Tamar
Key Biodiversity Area (KBA)/Conservation Area. One of our members was very concerned about a
fusillade of shots which seemed to come from the eastern shore on June 7. An earlier shooting episode
near the old George Town Road at Dilston had already been reported to the Wetland Centre. Duck
shooting ceased along the whole of the Tamar in 1979. The Conservation Area/KBA is managed by
Parks and Wildlife and extends from Launceston to the Batman Bridge.
Further contact with the complainants in Dilston revealed that two neighbours had
witnessed swans being shot just over the road. The details are quite graphic and were written in full
because of the proximity of the main road and they thought that the police may be involved.
Amazingly, although shooting is illegal within 250m of a property, there are no regulations regarding
shooting by a road – even though, in this case, there is a school bus stop nearby. It should be noted,
however, that the shooting was taking place parallel with the road, not towards it.
A string of letters to The Examiner regarding culling was picked up by the ABC in Hobart and
I was asked if Laura Beavis, from Launceston ABC, could contact me. A meeting with the local
residents and the farmer failed to placate several people and a further meeting was promised after
July 8. Days passed with further approaches from the ABC. No meeting seemed to be forthcoming
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so we decided to go out and do some filming. Too bad that a meeting was called for the very next
day.
The delay in holding a second meeting was in a way fortuitous because the time gap revealed
that 'clean kills' do not always take place. On June 21 one of our members took a photo of a swan
near the Wetland Centre which had the left wing missing. She took another photo of a swan on July
30 with the right wing missing. This situation was of course brought up at the second community
meeting on July 31 and the photo was tabled in Parliament by an agitated Greens member in the late
afternoon of the same day.
A Game Management representative produced a graph which purported to show a healthy
population of swans in Tasmania, but which was totally unconvincing because no reference was made
to the local breeding population, nor to local movements (in 2018 there were 90 breeding pairs on the
lagoons at Cape Portland. The Summer Count this year showed no breeding – no water – no swans).
It has been known since the late 1970s that swans can move just as ducks move in response to drought.
We can only speculate as to whether some swans in Tasmania are 'mainland swans'. No subspecies
of course, so no clues as to origin. However, we do have proxies – in the 4-year surveys for the Atlas
from 1998-2002 there are two records only of Pink-eared Duck. Last June there were 16 on the Tamar
wetlands. Freckled Duck showed zero records in the Atlas period, but in the last 2 years, over 100
have been recorded both in the Hobart and Launceston areas.
The Meeting at Dilston on July 31 aired both farm concerns as well as Birdlife issues. The
farmer was made aware of the importance of reed beds near both banks of the Tamar as habitat for
the endangered Australasian Bittern. Drone activity for moving swans could compromise breeding
activity and this was made known when the farmer thought he might try a drone to move the swans.
He had already tried crinkly silver paper, flags and gas guns to no avail. Shooting will no longer take
place on the Dilston marsh, which has been a breeding area for decades. Interference with nests and
eggs, which was suggested by a resident at the first meeting, will not be allowed under permit.
We acknowledge that there is a problem though – the presence of 500 swans on 20 ha of high-
protein grass (sown especially for breeding heifers) is entirely credible. It was established to our
Injured Black Swan, Tamar wetlands. Photo by Helen Cunningham.
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satisfaction that the severing of swans’ wings was caused by panic collision with fence lines and not
by shots.
A joint investigation by Birdlife and the ABC established that there are two licences, each with
a permit to take 100 birds per year, on both sides of the river. Both licencees could shoot at the same
time. So far this year, in addition to the two Tamar culling permits, there are 33 current permits in
undisclosed parts of Tasmania. The question of whether permits are/have been issued for more than
100 birds has not been answered. The total swan kill for the two farms bordering the KBA is 460
for the two years to the end of May this year. Permits may be issued at any time of the calendar year.
The kills for the last four years in Tasmania are:
2015 2016 2017 2018
2172 1677 2451 1748
At least we have opened things up for further discussion – Game Management seem adept at avoiding
disclosure of statistics unless really pressed.
In conclusion, it should be mentioned that discussion between the farmer and Birdlife was
entirely respectful on both sides. An account of the meeting which was submitted to Birdlife Tas
Committee was forwarded to the farmer in advance, and no significant changes were suggested.
Revisiting the Bird and the Blade By Nick Mooney
BirdLife Australia Raptor Group
The recent plethora of windfarm activity, including the controversial proposal for a 140km
transmission line eastward from the proposed Robbins Island/Jims Plains windfarms and media
inquiries around the recent release of the proposed St Patricks Plains windfarm’s eagle nest survey,
leads me to revisit the issue.
For years I have been assured by officialdom including the Tasmanian regulator (the
Environmental Protection Agency) and different government ministers that both ‘…a robust
procedure is in place…’ and ‘…the assessment process and offset program are under review…’. But
it seems that nothing substantial has changed since the mid-2000’s beginnings and we are still stuck
with oddly clunky assessments, lack of progress in the face of continued eagle strikes, many more
windfarm proposals (to date for more than 500 turbines). I think industry can and should do much
better and not just limit itself to simply what is required by the regulator.
Prevention of Collisions
Prevention obviously should be the priority but we fail immediately through a lack of strategic
planning. Some countries such as South Africa and Spain are ‘risk mapping’ their land to look for the
places with the best combination of wind suitability and low impacts on the environment. Here in
Tasmania we appear to just sit back and wait for someone to find enough money to build wherever
they can, essentially without environmental guidance. It’s simply pot luck whether a proposal is in a
high density of eagles and other values or not. Widespread point surveys of the Where? Where?
Wedgie type would be very useful in strategic planning for potential windfarm sites.
This complete lack of strategic planning stems from a lack of focus and will – the last Recovery Plan
for Tasmania’s threatened eagles (Threatened Species Section 2006) is now painfully out of date.
Much faith seems to be invested in a collision-reduction package being installed at the Cattle
Hill windfarm using camera recognition of flying eagles that slows/feathers nearby turbines to try
and reduce collisions risk. Well, the recognition part seems to work okay overseas but translating that
into actually reducing collisions has not been demonstrated anywhere. I hope it works.
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Assessment of Risks to Eagles of Particular Windfarms
Looking from the outside, the Eagle Utilisation Surveys used in assessment are not very useful. They
essentially consist of observers looking for eagles around the site and writing down where they think
the eagles they see are and how high they think they are flying. There are many sources of error,
beyond misidentification at a distance. The numbers of birds being seen (in a period) is not known
since there is no means of identifying individuals. Some eagles are curious and will rotate around
observers checking them out and eagles often shadow people to see what prey they might flush. So,
there can be substantial observer influence and double (and more) counting. Importantly, there has
been no calibration of judgments even though there are GPS-tagged eagles elsewhere in Tasmania
that could be used. Such direct observation to guesstimate factors that would greatly benefit from
precise measurement seems rather Dickensian in 2019 when GPS tagging is commonly used now for
such things. It seems almost perverse that the GPS-tagging eagle study in Tasmania that is producing
amazing data on things other than windfarms is partly supported by the windfarm industry yet the
tool is not used in their back yards (except for one tagged eagle in the northeast).
Eagle Utilisation Surveys are used to help locate turbines but windfarm industry publications
themselves claim that eagles modify their flight behaviours once turbines are constructed (eg Hull
and Muir 2013), somewhat making nonsense of the whole exercise. The enormous expense involved
in the current observational assessment might well be better directed at GPS tracking. Advocates
claim Eagle Utilisation Surveys lead to some nests being found but with the thorough searching for
nests that is undertaken I can’t see they are needed for that.
The location of nests already known or through a new Eagle Nest Survey leads to a buffer
distance of 1km to turbines nominated by the regulator (a distance the regulator has seen fit at the
Point Latta windfarm to reduce, under industry pressure). Unfortunately, the 1km is completely
arbitrary in terms of protecting eagles from physical danger and looks increasingly bizarre in the face
of ever-taller turbines
which almost loom over
some nests. And even if
the turbine base is 1km
away the huge blade
tips can be much closer.
The 1km is in fact ‘cut
and pasted’ from
guidelines I came up
with 30 years ago to
protect active nests
from the disturbance of
forestry operations.
One would think that in
2019 when spending
billions we might have
data-driven protocols
not just convenience.
Other countries are
using data from GPS-
tracked nesting eagles
to set the buffer
distance (usually more
than 4km). Flight
intensity usually
suddenly dilutes at a
certain distance from
Wedge-tailed Eagle, Tasmanian sub-species. Photo by Alan Fletcher.
Wedge-tailed Eagle, Tasmanian sub-species. Photo by Alan Fletcher.
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nests – that’s how buffers for physical safety are decided, not borrowing from a completely different
issue. The regulator mirrors the usual industry claim of ‘...no impact on nesting eagles…’ but quoted
publications also claim eagles change behaviours in response to turbines (isn’t that an impact?) and
the study on eagles breeding close to turbines (Hull et al. 2015) gives a clear warning about the study’s
lack of robustness.
Without marked birds and/or very sophisticated DNA study at windfarms and control sites
study it’s also impossible to know the turnover of eagles at windfarms and compare it to other areas.
They well might be population sinks and we wouldn’t even know with the current paucity of data.
Assessment of Population Impacts
Having enough GPS-equipped eagles of various age groups would allow the accurate estimate of
local survivability and population densities, essentials for a proper Population Viability Analysis,
without which any calculation of sustained yield and accumulated impact is unreliable. The Cattle
Hill windfarm proposal, for instance, came up with a statewide sustainable yield of 29 per year from
anthropogenic causes. Well, we know that many are killed on power distribution infrastructure alone
(forget accidental poisoning, persecution, collisions with turbines, vehicles and fences), highlighting
the estimate’s fragility.
My questions to the EPA on how it accounts for accumulated mortality in its assessments
simply go unanswered because with current poor data they can’t do the necessary sums. Now that in
2019 we have the means, the regulator should insist on high-quality data so meaningful assessments
can be made.
The regulator’s claim that windfarms cause no significant impacts on populations of Tasmanian
eagles is a familiar twist on the fact that there is no data to show they do – a very different thing. The
(scary) fact is, there is no data.
Assessing Mortalities
The miniscule areas searched under some turbines for dead or catastrophically injured birds (such
that fall almost straight down) is, at best, an uncalibrated index. Originally, larger areas were searched
but never with dogs, a method proven to increase detectability, especially of fragments of birds.
Therefore, the industry mantra and regulator mantra that what’s found represents what is hit seems to
me a somewhat Machiavellian feedback loop. Having enough GPS-tagged birds would give us very
exact measures of risk to eagles in and around windfarms.
Such assessment should, of course, start well before commissioning and it’s very disappointing
to see windfarm after windfarm avoid such direct study instead favouring sloppy methods that give
more 'wriggle room’. GPS study of enough eagles would allow calibration of the index the above
partial searches present and might even allow back-calculation of past mortality. But I am even
dubious about the value of the searches as an index in that the methods keep changing, especially in
regard to means of transport during searches (foot, quads, 4WDs etc) likely being a key factor
affecting detectability of dead and injured birds and bats.
Offsetting Impacts
Offsets in Tasmania have been varied, as allowed under the Commonwealth policy.
Importantly, the effectiveness of offsets in offsetting deaths and breeding disruption has not been
measured – their application so far seems more an act of faith than anything. Covenanting or
otherwise protecting private land around viable nests under threat from things other than windfarms
has the potential to offset nests compromised by windfarms but its effectiveness in terms of
productivity clearly should be routinely measured as part of the offset but isn’t. Extending
covenanting nest sites into compensation for eagle deaths is far more problematic in that productivity
would have to be elevated to compensate for the ages of different eagles killed (eg a dead juvenile
might be represented by 1 more fledgling whereas a dead adult might need 15 more fledglings).
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Offsetting mortalities per se however, has much more direct alternatives. Todd Katzner, a
leading American researcher in the field who also knows Tasmania advocated to me an obvious
offset often applied in the USA:
1. Measuring mortality/incapacitation estimates each year at the windfarm(s) (eg 5 deaths/year)
2. Measuring deaths/incapacitations from power-distribution infrastructure (eg 1 eagle/yr /200km)
3. Making (and keeping) the equivalent distance of line (eg 2 X 200 = 400km) bird-safe (this may
involve prioritising sections).
The alternative (1.) he describes is estimating deaths/incapacitations at windfarm(s) over the
proposed life span of the windfarm(s), proactively translating that into ‘bird safe-ing’ (eg 2
deaths/year over 30 years = 60 deaths which translates to 12,000km of distribution infrastructure,
which can have sections prioritised of course). This has the obvious advantage of accelerating the
solving of eagle deaths on power distribution infrastructure, a strategic approach that has much to
recommend it. The whole idea is to make sure the new industry (windfarms) leads to no net increase
in mortality and yes, it can be done.
As things are going, I fear all the windfarms will be approved before there is a useful
improvement, but it doesn’t have to be so. I say we use proper study to test the windfarm industry’s
and the regulator’s confidence that impacts of Tasmanian windfarms on eagles are insignificant at
population levels. I hope they are right.
References and additional reading:
Elliott, D (2019) Wind turbine impacts deplored. Physicsworld. 29 August 2019,
https://physicsworld.com/a/wind-turbine-impacts-deplored
Hull, CL and Muir, SC (2013). Behaviour and turbine avoidance rates of eagles at two wind farms in
Tasmania, Australia. Wildlife Society Bulletin, 37(1), pp.49-58.
Hull CL, Sims C, Stark E and Muir S (2015). Results and analysis of eagle studies from the Bluff
Point and Studland Bay Wind Farms 2002-2012. Pp. 95-111 in Hull, CL, Bennett, E, Stark, E,
Smales, I, Lau, J and Venosta, M (2015). Wind and Wildlife. Proceedings from the Conference
on Wind Energy and Wildlife Impacts, October 2012, Melbourne, Australia. Springer.
Dordrecht, Heidelberg.
White-bellied Sea Eagle (young adult). Photo by Helen Cunningham.
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Threatened Species Section (2006). Threatened Tasmanian Eagles Recovery Plan 2006-2010.
Department of Primary Industries and Water, Hobart.
Watson, R, Kolar, P, Ferrer, M, Nygard T and Johnston, N (2018). Raptor Interactions with Wind
Energy: Case Studies from Around the World. Journal of raptor Research 52(1) pp1-18.
What’s happening in my patch?
This is the first in a series of reports from different contributors about their ‘patch’: an area that they
have been monitoring for some time. We are also publishing ‘patch notes’ in the e-bulletin. The patch
reports are longer and more detailed than the patch notes; they describe and analyse observations
recorded during regular surveys. Patch notes can be about more informal observations. If you would
like to contribute to either series, please contact me. ― Ed.
In the foothills of kunanyi By Mona Loofs-Samorzewski
I live on the side of kunanyi/Mt Wellington in Hobart, in a little community of 13 houses with a range
of gardens in one half and bush in the other half – tall white gum trees, bracken and shrubs in the
understory and a moist rainforesty creek at the bottom. I’ve been keeping track of the birds there ever
since I moved in nearly 20 years ago, and it’s been interesting to watch the birds change and to see
how I have changed in the way I interact with the birds over that time.
In the first few years I just noted down all the different species I saw, to build up a list of what
was there, only adding a species when it was something new and not really noticing when or where I
saw the bird. After a while, adding a new bird happened more rarely, and I began to wonder about
the birds I saw regularly.
I decided to make a list of the birds I
saw each month, and this was a revelation! It
was over several years that I learned about
the comings and goings of the species in my
patch. I noticed that Fan-tailed Cuckoos,
Pallid Cuckoos and another curious
sounding bird which I heard for ages before
finally finding and identifying as a Shining
Bronze-cuckoo, all appeared and called in
the spring months, becoming less obvious
over summer and disappearing completely in
autumn and winter. Before my monthly lists
I vaguely noticed that I heard some birds at
some times and not others, but now I could
identify specific species and particular times,
which lead to reading up about cuckoos and
learning about their life cycles.
Many other birds followed this pattern: Black-faced Cuckoo-shrikes, Brush and Common
Bronzewings, Striated Pardalotes and Welcome Swallows. There were exceptions sometimes: a
surprise encounter with a Bronzewing in winter (aha, they just go quiet in winter but they are still
around!) and one year when the Striated Pardalotes decided to stay. But there were other patterns
also: Yellow-throated Honeyeaters appeared in summer and autumn, and were virtually absent in
spring. Golden Whistlers, Crescent Honeyeaters and Scarlet Robins did something similar but a little
later, turning up later in autumn and winter and continuing on into spring but gone by summer. I read
up in field guides and bird books about migration and was amazed to find out how many species leave
Tasmania over winter and how far they go. I also learned about altitudinal migrants, that come down
from the mountain in the winter months to take advantage of our gardens.
Black-faced Cuckoo-shrike. Photo by Michelle
Turner.
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I got to know the big obvious regulars: Masked Lapwing, Sulphur-crested Cockatoo, Green
Rosella, Grey Currawong, Black Currawong, Laughing Kookaburra, Grey Butcherbird, Yellow
Wattlebird, Common Blackbird and Forest Raven (it’s not a list if it doesn’t have a Raven on it!).
And the smaller, more unobtrusive regulars: Superb Fairy-wren, Eastern Spinebill, Black-headed
Honeyeater, Brown Thornbill, Grey Fantail and Silvereye. I discovered Tasmanian Scrubwren in the
creek, identified my very first Tasmanian Thornbill and watched Kelp Gull regularly fly overhead.
After a while these monthly presence/absence lists were not quite detailed enough, and I made a
commitment to do weekly lists including species counts and any breeding activity that I noticed. I did
this for all of 2016 and then again (although less consistently) in 2018. I tried going out at night and
met my first (and only) Masked Owl, realised that Tasmanian Boobook (called Morepork in some
taxonomies) also disappeared over winter, had a few lovely encounters with Tawny Frogmouths and
even heard an Owlet-nightjar! I’ve witnessed Australian Wood Ducks prospecting for nest sites (our
trees weren’t good enough apparently), Grey Currawongs raising chicks in messy stick nests, Superb
Fairy-wrens enjoying tangled blackberry shrubs to raise their families and heard the really weird
sounds that baby Yellow Wattlebirds make.
I’ve also noticed changes over time, such as the way all the European Sparrows suddenly
disappeared in June 2009 and it wasn’t until September 2013 that they recovered. A few birds I saw
early on (European Greenfinch and one Satin Flycatcher sighting) I’ve never seen again, and a few
new birds have arrived since I’ve lived here. The most notable arrival was the Tasmanian Native-hen
– I always wondered why we didn’t have
them, there was plenty of grass and water
nearby – suddenly in 2008 they turned up
and it’s never been the same since!
It’s great fun watching them
interact, they have raised many families
over many years and have split into the
Western Gang and the Eastern Gang with
predictable arguments when they meet.
Little Wattlebirds started appearing
around 2010 in autumn, they tend to hang
around for a month or two feeding on
Banksia cones, then they disappear until
next year. One newcomer I am not
particularly happy about is the Spotted
Dove, I first heard one in 2010 and since
the end of 2018 they have become more
regular, strutting around on the paved
surfaces like they’ve always been here.
Altogether I have counted 70 different
species, have been delighted by surprise
visitors (Swift Parrot and White-throated
Needletail to name a couple), enjoyed
getting to know my locals and learned a
lot about birds in the process.
BirdBanding NW Tasmania By Geoff Shannon Documenting population change in bird numbers is important, but what is the next step? It was with
this in mind that I started this project in early 2016 in an attempt to develop a figure for adult
survival year to year and some idea of immatures produced per year and their survival over the first
winter.
Tawny Frogmouth with chick. Photo by Helen
Cunningham.
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Eight sites in woodland were selected for this project and over the first 39 months more than
300 hours in the field have resulted in just over 1000 birds caught and more than 100 retrap events.
Twenty-nine species have been banded.
The top five species were Brown Thornbill (192), Superb Fairy-wren (158), Silvereye (111),
New Holland Honeyeater (94), Tasmanian Scrub-wren (92) and Yellow-throated Honeyeater (73).
Of interest was the variation in percentage of immatures from year to year: Tasmanian Scrub-wren
30-45%, Superb Fairy-wren 29 to 52% and Brown Thornbill 18 to 67%. This needs to be followed
for a few more years to see if there is a trend.
Retrap rates for Tasmanian Scrub-wren immatures were 27% and 25%, Superb Fairy-wren
12.8% and adult 13.6%, Brown Thornbill immature 15% and adult 25%.
This is a summary of Geoff’s fascinating talk at the July General Meeting of BirdLife Tas.
Mike Newman
At the last BirdLife Tasmania General Meeting, Mike described how he used Birdata to compare
the status of Pallid Cuckoos in Tasmania with the Hunter region of NSW where he used to live.
Pallid Cuckoos are summer breeding visitors to south-east Australia. In Tasmania 95% of the records
are between September and January, when the birds are highly vocal. In autumn they depart with
most spending the winter in north-western Australia.
In the Hunter region Pallid Cuckoos have become increasingly scarce over the last 20 years. In
contrast, Tasmania appears to be a stronghold of the species in the breeding season. Indeed, Birdata
surveys suggest that Pallid Cuckoos have increased in the last 20 years. However, that increase may
be an illusion because it is not supported by the trends at several locations where there are extremely
reliable data sets. At these locations the species has either remained stable or decreased, although
remaining plentiful in suitable habitat. Pallid Cuckoos favour dry woodlands with limited
understorey, ideally in a fragmented landscape which retains a high level of tree cover.
Understanding Birdata trends requires a knowledge of the lifestyle of the target species (e.g. its
habitat preferences). In the case of the Pallid Cuckoo it is also important to understand the
requirements of the brood host which raises the Pallid Cuckoo’s young. The literature lists 80
Female Superb Fairy-wren. Photo by Michelle Turner
Pallid Cuckoos
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different hosts, but individual cuckoos only parasitise one type of host species, Black-headed
Honeyeaters being a preferred host in south-east Tasmania.
Relatively little is known of the breeding behaviour of Pallid Cuckoos, but a related species,
the Common Cuckoo of the northern hemisphere, is exceptionally well studied. Female Common
Cuckoos typically find 20 to 25 brood nests, in which eggs are laid at 48-hour intervals. During that
period the female Cuckoo is extremely secretive as it watches its hosts and surreptitiously replaces
one of their eggs with one of its own. Males, on the other hand, roam widely, advertising their
presence to keep in contact and mate with the females. However, the male is also secretive and more
often heard than seen. It is probable that Pallid Cuckoos’ home ranges greatly exceed the size of
survey sites, as cuckoos roam in both their preferred habitat for food and that of the host, which may
have different habitat preferences. Collectively, these issues result in superficially anomalous survey
results, with the Reporting Rates of Pallid Cuckoos in the dry woodland of eastern Tasmania
exceeding that of its host the Black-headed Honeyeater by two or more times. However, Black-
headed Honeyeaters are clearly more numerous. The explanation lies in the loud, frequently uttered
calls of adult cuckoos in the breeding season, which increase their detectability.
There is evidence that adult Pallid Cuckoos may intervene in the care and ‘education’ of
fledged young. For instance, the food fed by host species may be very different from the hairy
caterpillars, grasshoppers and similar insects which are the staple diet of adult Pallid Cuckoos.
Mike’s article comparing Pallid Cuckoos in the Hunter and Tasmania will be published
on-line in Whistler, the journal of the Hunter Bird Observing Club, in the near future. – Ed.
Will this be a Shining Bronze-Cuckoo season? By Mike Newman
Spring approaches and the cuckoos return to torment their Tasmanian hosts. While there has been
recent focus on fluctuations in the abundance of Horsfield’s Bronze-Cuckoo the status of the more
common relative the Shining Bronze-Cuckoo receives little attention. Well that is until you are trying
to recapture ones carrying geolocators as described by Cat Young at our July General Meeting during
which she suggested that they were less numerous than usual last year in the Waterworks reserve
area.
Pallid Cuckoo, South Arm. Photo by Alan Fletcher.
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I decided to test the generality of this observation starting with my Meehan Range data where
I carry out monthly surveys at 6 2ha survey sites. The results shown below confirmed Cat’s
impression with no records in the 2018/19 breeding season and evidence of a five-year decline. In
contrast although the Fan-tailed Cuckoo has also decreased over the same period its numbers
remained relatively stable.
Figure 1. Reporting Rate trends of Shining Bronze-and Fan-tailed Cuckoos for breeding season surveys (Sep.
– Dec.) in the Stringybark Gully section of the Meehan Range.
To test the extent which these experiences were Hobart-centric I examined the whole-of-Tasmania
Birdata and found only limited support for the conclusion that there had been a serious crash in the
Shining Bronze-Cuckoo. The breeding season reporting rates of the more reliable 2ha 20- minute
Figure 2. Breeding season reporting rates of Shining Bronze-Cuckoos at Lake Llewellyn (5 km surveys) and
Woodsong (500 m surveys).
0
2
4
6
8
10
12
14
16
18
2014/15 2015/16 2016/17 2017/18 2018/19
Rep
ort
ing
Rat
e (%
)
Shining Bronze-Cuckoo Fan-tailed Cuckoo
Linear (Shining Bronze-Cuckoo) Linear (Fan-tailed Cuckoo)
0
10
20
30
40
50
60
70
2010/20112011/2012 2012/20132013/2014 2014/20152015/20162016/2017 2017/20182018/2019
Rep
roti
ng
Rat
e (%
)
Lake Llewellyn) Woodsong Linear (Lake Llewellyn)) Linear (Woodsong)
13
and 500m survey sets were 4 and 19% lower respectively than in the previous year (2017/18). There
was a larger decrease of 33% in the 5 km surveys which are strongly influenced by Richard Ashby’s
surveys at Lake Llewellyn in north-west Tasmania, which are shown in Figure 2.
Wondering what had happened in north-east Tasmania, I compared the trend at Woodsong
using Albert Nichols’ surveys and again found that Shining Bronze-Cuckoos were at a near decade-
long minimum in 2018/19.
There is an interesting similarity in the trends at Lake Llewellyn and Woodsong with both
indicating a long-term decrease in separate regions of the state. Both also show periodic fluctuations,
which may be a consequence of the Cuckoos shifting to another area to prevent their host becoming
habituated to their presence.
Richard, Albert and I will return to our patches this spring hoping our Cuckoos come back and
we all wish Cat success in recovering her geolocators so that she is able to tell us where they went.
Eyes bigger than stomach? By Sue and Warren Jones
Each year over winter we get occasional visits from a Grey (=white) Goshawk in the garden of our
house in Kingston. Our neighbour has an aviary, and the goshawk has been known to perch nearby
eyeing off the lovebirds.
We are sometimes alerted to the goshawk’s presence by ‘angry raven’ calls when our resident
pair of Forest Ravens spot and then see off the interloper. Usually this has seemed a very one-sided
affair as both ravens, occasionally aided by the local Grey Butcherbird, continually harass the
goshawk until it leaves the area. However, this year on two occasions the goshawk has flown directly
at one of the ravens which was perched in a tree. On the first occasion we thought it may have been
just trying to chase the raven off, but on the second occasion it looked a little more serious and we
wondered if the goshawk saw the raven as a potential meal, notwithstanding that the goshawk looked
no bigger than the raven.
A little research suggests that this is possible. A chart in Olsen’s Australian Birds of Prey
shows that a male Grey Goshawk may take prey of up to 800g, while a female may go as high as
The visiting Grey Goshawk. Photo by Sue Jones.
14
1300g. They can, and do, take prey bigger than themselves. Menkhorst et al. (2017) record the
weight of Forest Ravens as 500–770g. More detailed information on the diet of the Grey Goshawk
in Tasmania has been collected by Nick Mooney and reported in Olsen et al. (1990). Looking at the
diet in both the breeding and non-breeding seasons, this paper records 30 species of birds (62
individuals) as prey items in Tasmania. Mammals and reptiles also form a portion of the goshawk’s
diet. The smallest birds recorded as prey are fairy wrens and thornbills (a light snack?) ranging up to
the heaviest bird being a single Forest Raven taken by a female Grey Goshawk. Other large birds
recorded as prey include a white-faced heron, cattle egrets, a kookaburra and currawongs.
So, it seems that our ravens are right to be wary of Grey Goshawks and to drive any that appear out
of their territory as quickly as possible. Juvenile ravens or sick or injured adults would be at most risk
and healthy adults may be vulnerable only to the larger female goshawk. For now, and especially
when working together, our pair seem to have the upper hand.
References:
Menkhorst, P, Rogers, D, Clarke, R, Davies, J, Marsack, P and Franklin, K (2017). The Australian
Bird Guide. CSIRO Publishing.
Olsen, P (1995) Australian Birds of Prey. UNSW Press.
Olsen, PD, Debus, SJS, Czechura, GV and Mooney, NJ (1990). Comparative Feeding Ecology of the
Grey Goshawk Accipiter novaehollandiae and Brown Goshawk Accipiter fasciatus. Australian
Birdwatcher 13, 78 – 192.
BirdLife Tasmania news and views
Australian Bird Environment Fund (ABEF) grant Congratulations to Mike Newman – due to his hard work, BTas was recently awarded ABEF funding
of $9000 for a project aimed at sustaining and enhancing recent gains in Birdata participation and
data evaluation. It will be a joint project with the BirdLife research team. The project has four
components:
• Production and publication of the State of Tasmania’s Birds 3 for Tasmanian Bird Report No.
40.
• Conducting workshops which explain Birdata to Tasmanian members and the broader
community. The purpose of these workshops will be to encourage increased monitoring of
bird populations in a meaningful manner and to facilitate the increased of application of
Birdata to environmental management.
• To identify gaps in the Tasmanian Birdata set that limit its use in determining the status of
bird populations and to develop strategies for addressing these deficiencies thus increasing
the effectiveness of our volunteers.
• To develop and trial approaches to assessing the health of bird populations in Key Biodiversity
Areas which are seldom visited.
This program will be carried out over the next 18 months.
Draft Tasman National Park Fly Neighbourly Advice (FNA) The Parks and Wildlife Service (PWS) advises that it has prepared a draft Tasman National Park
FNA. The draft FNA was made available for public comment on 24 August 2019 for a four-week
period until 21 September 2019.
The draft FNA has been prepared by the PWS in response to increasing air traffic over the
southern section of the Tasman National Park and adjoining areas. Whilst the PWS does not have
management authority over the airspace above the Tasman National Park, the PWS is facilitating
the FNA process - for the benefit of park visitors, values management, and local residents.
15
The draft FNA is available on the PWS website at www.parks.tas.gov.au/publications (under
‘Other Publications’).
Following public consultation, the PWS will provide the draft FNA to the Regional Airspace
and Procedures Advisory Committee for consideration. If endorsed, the FNA will be published in
aeronautical charts as a resource for pilots.
Listing of threatened species and communities In late June, the new Federal Environment Minister added a number of species and communities to
the threatened species listed under the Environment Protection (Biodiversity Conservation) Act 1998.
See:
http://www.environment.gov.au/news/2019/06/28/amendments-epbc-act-list-threatened-species-
and-ecological-communities
White-throated Needletails are now listed as Vulnerable and the Ecological Community:
‘Tasmanian Forests and Woodlands Dominated by Black Gum or Brookers Gum (Eucalyptus
ovata/E. brookeriana)’ is listed as Critically Endangered (as was recommended by the independent
Threatened Species Committee several years ago, and was stalled following the intervention of the
Tasmanian Government).
Southern excursions
North-west walks and talks The September 17th bird walk will be at the Devonport
Arboretum (Eugenana) starting 9 am. Meet 8.30 am at the
information bay Alexander Street, Shearwater.
I have also been able to organise a viewing of the raptor
photo exhibition at the education centre. (Five-dollar entry fee
to the Arboretum if not a member).
Please contact BirdLife Tasmnia if you would like to go
on the email list to find out about future walks: tasmania@birdlife.org.au
Twitchathon 2019 The Birdlife Australia National Twitchathon is a fun event
where teams of birders attempt to see as many species as
possible in a given time period, while raising funds for conservation. This year, the Tasmanian
component of the Twitchathon will be on the 26th and 27th of October, and raising money for King
Island Scrubtit and King Island Brown Thornbill habitat restoration through Birdlife Australia's
Preventing Extinctions program. Anyone can sign up for the 3-hour Birdathon, the 12-hour Big Day,
or the 30-hour Big Weekend anywhere in Tasmania, and get out and about for some birdwatching
fun with a twitching twist!
Sun 22nd
September
2019
8:30am
Ridgeway
Reservoir
One of the current Tasmania Fire
Service survey sites, part of the study
examining differences in utilisation
between original and recently burned
sites, using 20 min, 2 ha surveys and
the Birdata database
Contact BirdLife
Tasmania for more
information.
tasmania@birdlife.org.au
Sun 20th
October 2019
8:30am
Waverley Flora
Park
Enjoy a spring trip to the wonderful
Flora Park on the Eastern Shore.
Contact BirdLife
Tasmania for more
information.
tasmania@birdlife.org.au
The Tasmanian Arboretum
Presents
A Photographic Exhibition
The Raptors of Tasmania
Showcasing the images of local
photographers:
* Bert Quandt * Jill Colgrove
* Peter Tonelli * Greg Close
* Mehrdad Abbasian * Philip Milner
September 14th & 15th and 21st & 22nd
10 am to 4 pm each day in the
Arboretum Education Centre.
46 Old Tramway Road Eugenana
Admission: $5.00 for non-members
16
For more information, contact the Tasmanian coordinator by email at twitchathon.tas@gmail.com,
or visit the Tasmania Twitchathon page at https://www.facebook.com/TasTwitchathon/
Opportunities for involvement Please contact us if you would like to find out any more about the various opportunities and tasks
below. Email tasmania@birdlife.org.au and your email will be forwarded to the appropriate person
for response.
Layout person/graphic designer needed for Yellow Throat Yellow Throat is in need of a facelift. Improving the layout is beyond the capabilities of the current
editor, so if you have layout/graphic design skills and would like to contribute to BirdLife in a
rewarding and interesting way, this is a great opportunity to be involved. The commitment involved
would be 4-5 hours once every three months, starting in late November 2019.
Tasmanian wildlife fair – Koonya
We will have a stall at the Tasmanian wildlife fair again this year, on October 5, and need a couple of
volunteers to help ‘person’ the stall. This is a colourful, fun and very valuable event.
Assistance with Yellow Throat production
We would like to have a team of people to call upon for assistance with printing and posting the paper
version of Yellow Throat. The commitment involved is only 1-2 hours every three months, starting
early December 2019.
Engagement sub-committee
The Engagement sub-committee of BirdLife Tasmania meets irregularly in Hobart to discuss how we
can improve communication with and involvement of members and supporters, and we also then
work on the solutions! We are a lively, committed group of people with a range of skills and interests.
November BirdLife Tasmania General Meeting November’s general meeting will be held on Thursday 14 November. Todd Dudley, President of the
East Coast Bioregional Network, will give a presentation on the East Coast Conservation Corridor.
The venue, as usual, will be Life Sciences Lecture Theatre 1, Life Sciences Building, University of
Tasmania, Sandy Bay. All welcome.
Scarlet Robin. Photo by Michelle Turner.
17
BirdLife Tasmania 2019
GPO Box 68, Hobart 7001
tasmania@birdlife.org.au
www.birdlife.org.au/tasmania
Unfortunately, due to recent issues involving scamming emails, we cannot include
individual contact details. Please address all correspondence to BirdLife Tasmania via
tasmania@birdlife.org.au and your email will be forwarded to the appropriate person.
BirdLife Tasmania | Facebook
BirdLife Tasmania (@BirdLifeTas) | Twitter
Yellow Throat is produced every quarter beginning in March. Contributions, including
articles, sightings, birdwatching sites, photographs, letters and news, are welcome,
and will be published subject to space and interest or relevance to BirdLife Tasmania
members, at the Editor’s discretion. Views expressed in Yellow Throat are not
necessarily those of BirdLife Tasmania, or of the Editor, unless explicitly stated. The
deadline for the next issue is 20 November 2019.
All photographs remain © the photographers. We are very grateful to them for
the use of their magnificent images.
All maps drawn from the BirdLife Tasmania database remain © BirdLife
Tasmania.
Please make use of our material, but we ask that you acknowledge BirdLife
Tasmania as the source.
Shining Bronze-cuckoo. Photo by Alan Fletcher
18
We thank the office of Mr Andrew Wilkie, MHR, for assisting in the production of Yellow
Throat 107.
BirdLife Tasmania is a regional branch of BirdLife Australia
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