Hi all
As most of the storages along the Murray and its tributaries contain little
water, it is unlikely that environmental water will be released in the
foreseeable future. It is hoped, however, that environmental water can be
released into a few small wetlands so that they can act as drought refuges
for native fish and waterbirds.
Whilst camping at Jingellic (across the Murray from Walwa) over the new
year, I heard that there will be no further releases of water from
Jindabyne and that the Murray could cease flowing later this year! The
Murray is still flowing strongly through Echuca-Moama at the moment, with
much of the water destined for Adelaide. But local wetlands have either
been drained or allowed to dry out.
Almost all of the wetland areas in the Barmah-Millewa Forest are dry. The
Reed Beds near Picnic Point (southern Riverina) have been dry for several
months. Even 'permanent' wetlands such as Hut Lake in Barmah Forest, have
now dried out. Permanent wetlands provide a drought refuge for both native
fish and birds.
I have just been forwarded an interesting email report ~ which was written
by Keith Ward last month ~ outlining the effects of drought on wetlands of
the Barmah-Millewa Forest. Birding-Aus subscribers who reside in the
vicinity may be interested in the following.
Having mentioned that a major drought refuge, Hut Lake, had all but dried
out, Keith Ward states, "Fortunately it is not all doom and gloom. The
drying bed will consolidate and aerate the sediments, alter the
phys-chemical properties, and may serve to strengthen macrophyte
communities upon re-wetting. Giant Rush, an indigenous species that is,
unfortunately, taking over too much of the rich biodiversity of the Moira
Grass Plains, will not find the conditions favourable. This is a good
thing."
It sure is! In order to provide a rich source of food for water birds,
wetlands need to dry out at times. So, when the wetlands next receive
water, there should be lots of food for waders and other waterbirds.
But Keith Ward points out a paradox:
"the drought paradoxically often means that parts of the Barmah wetlands
get wet. No, this is not a typo - just a consequence of the Murray River
being run too high in the quest of river managers' attempt to deliver as
much water as possible through the Barmah Choke (a natural constriction
within the river channel). The Giant Rush stands in those wetlands are in
complete heaven, and their advancement this year will now be about the last
nail in the proverbial coffin for many Moira Grass plains. This is
definitely not a good thing."
My comment: Before irrigation, the Murray usually flooded the Moira Grass
plains in spring,drowning and killing any young Red Gum saplings which had
germinated since the last flood. With river regulation, flooding is less
frequent and the floods are lower, so the area of Moira Grass plain has
contracted, Red Gum saplings taking over. Most of the Moira Grass plains
have been lost. Obviously, the loss of this habitat has had an effect on
the makeup of the local bird population. I assume that some birds have
suffered, e.g. Brolgas, seed-eaters, whereas others have benefited, e.g.
White-plumed Honeyeaters, nectar feeders.
Anyway, Keith Ward continues,
"But it gets more interesting - What isn't wet or dry has been burnt. A
large fire that begun in mid-October, under suspicious circumstances, burnt
about 800 ha of Redgum-rushland wetland system (pictures not included
here). Approximately 300 ML of water was diverted from the Murray River to
successfully douse some difficult to reach hot spots, however the fire
continues to re-ignite elsewhere from subterranean sources (i.e., is
smouldering along roots until it re-surfaces in an adjoining tree). So
much for the 'grazing reduces blazing' adage being exposed by those with a
vested interest. Someone should have told the cattle that they need to eat
the unpalatable rush instead of facilitating the spread of it. The
flammability of the material, according to the firefighters, was
practically beyond belief!
"Despite this, the fire has actually provided a unique opportunity to
reduce the Giant Rush biomass. If we were now only to get some deep and
long duration flooding, then the Moira Grass may have the opportunity to
re-dominate. But like any good thriller, we now have a new surprise
contender - Arrowhead. This introduced species is rapidly taking over vast
areas of wetlands and water supply systems throughout north-eastern and
north-central Victoria, including Barmah. It prefers shallowly flooded
open systems, and has so far failed to colonise Top Island because of the
Giant Rush. But with the rush now out of the way, and Arrowhead choking
every waterway leading into the wetland, conditions are now set to enable
this species to take over when the river next rises."
Comment: Unfortunately, Arrowhead is only one of several invasive water
weeds threatening the Murray system.
I hope Keith does not mind me quoting from his email. I have mislaid his
email address and hence not run this past him. The original email had
several pictures by way of illustration. Obviously, I cannot include them
here.
The Echuca Branch of BOCA has arranged an evening cruise through Barmah
Forest on 17th February and details are on the branch's web site (which a
Google search should help you locate). There are only a few vacancies (the
flat-bottomed 'Kingfisher" only carries about 25).
There is a great deal of information about the Barmah-Millewa Forest and
other local bushland areas, plus a gallery of local birds and more, on the
Echuca and District BOCA web site. There are pdf brochures on nine birding
locations, including Barmah Forest and Mathoura/Gulpa Island/Langmans
Sandhill.
The birds in our region are having a hard time, with drought essentially
entering its thirteenth year and fires combining to damage their habitat.
And it's not only waterbirds which are suffering. Bush bird numbers have
been roughly decimated (which apparently means reduced by 10%) in some
years. But the same range of birds can usually be found, just that the
numbers of most species seem to have fallen.
One of my favourite local birding spots is Langmans Sandhill on Gulpa
Island. Two of us camped there a few weeks back and arrived to find part of
the area being heavily logged. Despite this, we observed about 50 species,
including Superb Parrot, White-browed Babbler, Gilberts Whistler, Diamond
Firetail and Brown Treecreeper. Fortunately, several hectares have been
fenced and declared an 'exclosure'. The exclosure protects Calytrix, Golden
Wattle, some of the last remaining Banksia in the forest, Hop Bush and
Exocarpus. Particularly popular with Crimson Rosellas (yellow form) were
the few Golden Wattles. Most of the Banksias seemed dead or dying. I hope
that the birds here are able to survive the drought and the logging.
Rainbow Bee-eater numbers have yet to recover locally from a sudden drop in
temperature in February 2005 which resulted in the death of many adult
birds and chicks. We only observed about 7 during our annual count at the
end of 2006, up 7 on the previous year. Fortunately, I observed lots of
them nesting whilst holidaying at Jingellic (Upper Murray) over the new
year.
The billabongs alongside the Murray near Jingellic were all dry. Although
we observed few waterbirds, we saw some good bush birds, including a
Rufuous Fantail in a dry riverside gully. Another highlight was the
sighting of a Lyrebird in dry country at the foot of Pine Mountain. In the
Murray afront our camp site, pair of Black-fronted Dotterels had a nest.
After a couple of days, their egg hatched and we spent much time watching
the young chick. At one stage we had to shout at a couple walking on the
other side of the river to call their dog as it was about to catch the
chick. Fortunately,the chick survived.
Here are some interesting observations of late. Unlike past years, some
birds in the Echuca district have moved in close to farm houses, e.g.
nesting on verandahs, close to water sources. A week or so ago, a huge
flock (about 800) of Short-billed Corellas was observed around Moama
whereas in the past almost all corellas have been Long-billed and very few
Short-billeds were observed, usually with the Long-billed. I've not
observed such a huge flock here before.
Keith Stockwell
Echuca-Moama
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