Hi Tim,
Thankyou for your interesting research on Song Thrushes.
I'm sure you need another distraction from book editing etc, so here is one
I have wondered about.
The territory requirement of Song Thrushes (4ha) versus Blackbirds (0.3ha)
reminds me of something I have observed and wondered about in 2 of out local
urbanised natives - Red and Little Wattlebirds. Little Wattlebirds have only
become resident in my area (Coburg, Melbourne) within the last 5-10 years.
Reds have been here all the time I've been here ~30yrs. I suspect these 2,
while occupying similar habitat niches, like the Song Thrush and Blackbird,
have very different home territory requirements.
Reds live and breed very successfully (up to 3 or more broods a year, often
with 2 young/brood fledging) in and around my and my neighbours garden.
While I have not studied it in detail, the pair appear to use an area of
only about 7 or so of our house blocks. They are also quite inventive with
nest sites. For one or more seasons they nested in a small (~2m high) Pencil
Pine in the 'garden' (~3sq m grass, 4 small Pencil Pines) of the huge
"palace" across the road. Food collecting occured elsewhere!
I am not sure if the Littles breed here, though the first arrivals nearly
drove my then (nightshift working) partner to 'bird-icide', calling, LOUDLY
all day for weeks, for a mate. There is little calling in recent seasons so
I assume there is now a pair.
The next pair of Reds seem to live only one residential cross street away.
Not sure where the next Little pair lives, but my feeling is, it is much
further away.
While their larger size may mean the Reds are better able to harass/compete
with the Littles, I wonder if they are also better able to utilize the
strange variety of food on offer in an urban area like this. Apart from
their traditional diet of insects and nectar from my Eucs etc, the Reds are
happy to eat my figs, apricots and other fruits - being very polite and
eating most of the one fruit, not sampling (damaging) all on the tree like
some birds do. They also nectar feed from non-native trees in my neighbours
garden such as camellias. I think I have also seen them eat dog food and
other unnatural things. The Reds can also tackle some impressive prey items.
I often become aware of the first emergence of Greengrocer Cicadas, when I
find the poor creature being dismembered and eaten by a Red Wattlebird
I suspect the Littles are more specific, less adventurous feeders. I see
them feeding in native blooms and hunting bite-sized insects. They seem to
be more wary than the Reds and stay higher in the trees. I see Reds hopping
about on the ground hunting and foraging (and dismembering cicadas!) - never
Littles.
I also wonder if this territory size difference is only a phenomenon of
urban habitat. Or is it the same in the bush?
Any thoughts Tim, or others?
Wendy Moore
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