It was a lovely sunny day in Brisbane the other day - temperature in the
low 20s and views to the Great Dividing Range from Albert Park. The
weather reminded me to put some notes together on the casual
observations I made in the three years of life in Perth [waterfowl
capital of Australia].
Perth has more lakes than you can poke a stick at, and the Uni I worked
at [in Mt Lawley] had a neighbouring park, complete with lake and
vegetated island. I could watch the Carnabys cockatoos having fun with
the pine [radiata] cones outside my office window and the maggies
swooping unfortunate school children who passed through the car park.
The maggies had it in for anyone with skates or a skate board and would
glide in like stealth bombers before making a racket beside the
unfortunate's ear. They were very selective in their harrassment and
never bothered me when I walked through the car park or rode my bike
down the street.
Anyhow, I had my lunch in the park virtually every workday [you can do
that at Perth, because although it gets more rain in winter in Melbourne
the weather is a much nicer - you only have to stand behind a tree for a
few minutes while the rain belts down then back out into the sun -
rarely ever any lingering drizzle].
That gave me plenty of time to observe the birds residing at the lake.
When they were in residence, a pair of swans were lords of the lake.
None of the other birds messed with them, and if they saw someone doling
out food on the other side of the lake, they would fly in and land [in
the water because that is easier] wherever was convenient - if that
meant landing on the ducks that was tough [the latter proved very adept
at ducking, so I never observed any collisions].
There were also groups of maned and pacific black ducks and the
occasional shelduck living by the lake [none of the more interesting
species that inhabited the other lakes - pinkeared, bluebilled, musk and
Oz shovellers turned up, which probably makes sense since it was a
fairly shallow lake].
The PB ducks were more prolific in their breeding at the lake, and from
time to time flotillas/platoons could be seen making their way around
the place. It was interesting to see that while the ducklings were
competent divers, the adults appeared to be too bouyant [which is why
they are dabbling divers]. While being unable to fly, the ducklings
were amazingly fast through the water - they appeared to wiggle rather
than paddle].
There were a few domestic ducks that hung around the lake, and from time
to time they would have broods of chicks, but never seemed to managed to
raise any [the chicks would disappear one by one]. The larger of the
swans seemed to have it in for one of the domestic duck and would give
her a thorough going over it if caught her on the open water.
PB ducks are not very large, and in addition to being bossed by the
swans and domestic ducks, they were also pushed around by the coots.
The coots provided the main entertainment at the lake. There were
plenty of coots around the lake, and these were governed by 2-4 breeding
pairs [the island was a natural nesting site].
The breeding pairs had well defined territories, and I got to see heaps
of stand-offs along invisible boundary lines. Sometimes it was a simple
staring match at the border and sometimes there was some serious leg
wrestling - the coots lie back on their wings and try to push their
opponent under water with their legs [very comical to watch]. Typically
at the end of a bout, the coots would turn ritual circles in the water
and swim back into their territories.
Generally if one bird got caught in a border dispute, its mate would
rush over [half running, half flying] to lend assistance.
The dominant males were not backward in putting the immatures in their
place. If on land, the dominant males would stalk forward with their
heads held menacing low and forward before breaking into a run when they
got close. In the water, there were many slow 'line astern' chases
[coots aren't very fast swimmers and they tend to labour when they are
in a hurry].
The coots tended to have 3-5 chicks per brood. I never saw the parents
attacking their chicks [as David A. suggested in the 'Life of Birds'].
The parents would get their chicks out onto the water when they were
still tiny red-capped balls and fed them sludge from the bottom of the
lake. The coots had an interesting way of diving - pushing up before
ducking down. The coots were very concientious in feeding their chicks,
and put plenty of effort into breaking food up into manageable sizes for
them.
The immatures tended to form a collective after they had been kicked out
of their parent's territory. They ate a lot of grass, and they were
prone to eating while lying down if they were feeling comfortable and
relaxed.
There were also a couple of moorhens living on the lake. [Other lakes
tended to have proportionly more moorhens than was the case here]. For
some reason, these moorhens were pretty shy and they tended to be cowed
by the coots, but being slightly larger could beat the coots when
cornered.
There were also a couple of breeding pairs of Oz grebes on the lake.
They made lots of noise for such small birds which spent a lot of time
under water. They engaged in lots of frenetic chases across the lake,
which were punctuated with underwater stretches. They also engaged in
ritual circling, though it was more of a getting together than a dusting
off. As you could imagine their chicks were minute and very hard to
spot when they first left the nest.
Other birds round the lake included reed warblers [which tended to stay
out of sight as is their wont]. A range of herons, egrets, spoonbills,
cormorants and darters would turn up from time to time to engage in a
bit of fishing. It was interesting to watch the cormorants swimming
around the shallows chasing the knuckled sized fish, and they did catch
the odd yabbie.
The pick of the visitors were the rufous night herons who roosted in the
willows by the lake.
Next time you are in Perth, spend some time by a lake - you might see
something interesting - a hoary headed grebe, a great crested grebe, an
elegant parrot, a little eagle, a swamp harrier, a few glossy ibis, a
chestnut breasted rail or a spotless crake ...
Laurie.
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