Ahhh… winter!

Ross Creek, Townsville
Ross Creek at Sandy Crossing on a winter’s morning

Our few days of rain last month, welcome as they were, seem to have been an aberration and we’re now enjoying a normal Townsville winter – cool nights, warm days, blue skies and humidity low enough that static electricity sparks off car door handles. Every second person you meet asks, “Isn’t this weather gorgeous?” and the answer is always some version of, “It sure is!”

I paused at Sandy Crossing quite early one morning last week for this photo. The dew was still on the grass and the birds were moving around the mangroves – Brown Honeyeaters making far more noise than their size seems to warrant, as they so often do; a Rainbow Bee-eater perching watchfully on the power line; and a little gathering of Woodswallows not far away.

White-breasted Woodswallow
White-breasted Woodswallows welcome the sun

Townsville’s dry season begins

Pied Imperial-pigeon in treetop
Pied Imperial-pigeon in the topmost branches of our poplar gum

Easter seems to me to mark the usual turning point between Wet and Dry seasons here in Townsville, and it has certainly seemed so this year. Cyclone Debbie was looming as we left for Bali on March 25 but by the time we returned, a week ago, humidity had dropped right off, nights were noticeably cooler, the frangipanis were losing their leaves and the prospect of more real rain seemed to have evaporated.

I would love to be proven wrong on this, because Continue reading “Townsville’s dry season begins”

Pheasant Coucal in the suburbs

Pheasant Coucal
Pheasant Coucal in the batwing coral tree

Coucals are infrequent visitors to our suburban Townsville garden but we saw this one this afternoon after seeing another, or perhaps the same one, a couple of days ago. As chance would have it, a friend I spoke to this morning mentioned that he had seen one in Annandale, just on the other side of Ross River from us, in the last few days.

We were inclined to think that they come into town along the Ross River parkland, which forms a continuous wildlife corridor from the (rapidly drying) Ross Dam to the mangrove-fringed estuary in South Townsville.

This post presents more information about the species, so I won’t repeat it here.

Dry-season butterflies in Townsville

Cairns Birdwing
Male Cairns Birdwing

I don’t like to brag, but we have so many Cairns Birdwings in our garden that I rarely bother pointing a camera at them. When one poses as beautifully as this, however, and I happen to have a camera in my hand, I do take advantage of the opportunity.

At the moment we have at least two semi-resident male birdwings spending their time chasing each other away from the Aristolochia vines while hoping a female will turn up. They may not have too long to wait, since we do see females as often as males.

Also around the garden in this unusually damp ‘dry’ season: Common Eggfly (male and female), Chocolate Soldiers, Grass Yellows, Skippers,  Plumbago BluesLemon Migrants and Crows (links will take you to older posts and photos). I think that’s about all, other than the solitary Lurcher which popped out of the shrubbery yesterday. It may be the same individual we found at the end of July, since this one is clearly no longer young.

Lurcher butterfly
Australian Lurcher on sacred bamboo

Mistletoebird and Flycatcher

Leaden Flycatcher in shrubbery
Leaden Flycatcher

We’re well into the Dry season now and, as I said when I introduced the Leaden Flycatcher two years ago, the bird population of our garden builds up as the surrounding countryside dries out. We’re going to see even more this year, actually, since Townsville has just gone on to Level 3 water restrictions, meaning that parks and most gardens will also dry out while our bore water will keep our garden green.

Photographing the smallest birds is a special exercise in patience and luck. Many of them like to forage in dense shrubbery where they can move freely but bigger birds can’t, and where they are safer from attack. They are also safer from the paparazzi, since they rarely offer a clear shot (the oddly blurred background of the photo above is out-of-focus foliage) and they are often in shadow or dappled light.

Which species am I talking about? Particularly Sunbirds (11 cm), these Flycatchers (15 cm) and White-throated and Brown Honeyeaters (both about 14 cm). (By way of comparison, the Cairns Birdwing butterfly has a wingspan of 12 – 15 cm.) Spice Finches (11 cm) are just as small but at least they tend to feed in the open.

The Mistletoebird, Dicaeum hirundinaceum, is another member of the list. At 10 cm and 9 gm (the weight of two teaspoons of sugar) it is one of our smallest, and it flits about erratically, high in the tree canopy.

Mistletoebird
Mistletoebird high in our paperbark tree

As Bird in Backyards notes, Mistletoebirds are found Australia-wide and feed on berries of the plants they are named for, having an important role in distributing the seeds. Mine is a male; the females are basically grey, darker above than below. The species is our only member of Dicaeidae, the Flowerpecker family. Its nearest Australian relatives seem to be Sunbirds.

Dry season, 2016

Just over a year ago I wrote:

The Dry arrived this week, with an almost-audible thump: humidity halved between Tuesday and Wednesday. After hanging around the high fifties (RH at 9 am, figures from this chart) for the first three weeks of [April], it was 22, 32 and 52% on Wednesday – Friday this week …

The same change of weather hit us yesterday and last night, three weeks later than last year. For me, at least, it’s the confirmation that our Wet has truly ended – not that we really needed one, since the only rain we had in April was about 20mm in the middle of the month, as per the BoM data, and we’ve only had a bit of drizzle this month. The garden has been telling us, too: the frangipanis are shedding their leaves and the Cape York lilies have died back, amongst other indications.

In the six months November-April we’ve had rainfall totals of 26, 111, 76, 95, 558 (March was a good month!) and 21 mm respectively, for a not-so-grand total of 887 mm. March alone put us well above our record-low 2015 rainfall total but we would still have liked more. Ross Dam is at 26%, an alarmingly low level for the start of the Dry. I may say more about that in a follow-up post but, meanwhile, the TCC chart here will show you what’s going on.

Townsville’s record-breaking 2015 rainfall

I have been grumbling for months about how dry Townsville has been in the last year, and the annual figures are now in: 2015 was the driest year on record, with just under 400mm compared to our average of 1135mm and our highest-ever of 2400mm. We have just continued the pattern by completing a dry January, 77mm compared to an average of 270.

tsv-rainfall-low-highMy figures are from the BoM’s Climate Data Online for Townsville airport, here (I have rounded them off to the nearest whole millimetre). Looking at the annual rainfall totals in that table, a pattern pops out: four-digit and three-digit totals don’t alternate randomly but come in clusters, 3-5 of each at a time. For instance, 2001-06 were all below 1000mm, while 2007-12 were all above it. Extracting the first and last columns and colouring the totals blue for wet years and brown for dry years (see table at left; click on it for a larger version) makes the pattern more obvious, and highlights one other quirk: a run of dry years is sometimes interrupted by a single wet year (e.g. 1968 and 1981) but the converse isn’t true.

tsv-rainfall-low-mid-highI also divided the range of annual totals into three: close to average (1000 – 1300 mm), wet years (more than 1300) and dry years (less than 1000). Colouring them appropriately brings out another feature, showing just how rare an “average” year is: only one year in five is within that zone.

Monthly rainfalls also vary wildly. I could repeat the same exercise for  (e.g.) January rainfalls, where the average is 270mm but the actual figures vary from a mere 9mm to 1142. We can’t even say that a wet January is particularly likely to be followed by a wet February and March. Sequences like 85 – 549 – 53mm (2002) and 19 – 316 – 73mm (2003) are not uncommon.

In fact, we have to realise that an average month or year is not at all normal.

Climate is what we expect, weather is what we get

So can the statistics tell us anything useful at all? Well, yes. They can obviously say things like, “Yes, 2015 was much drier than usual. It wasn’t your imagination.” They can also warn us not to expect an average month or year, something that long-term residents are vaguely aware of but many newcomers are not.

More subtly, they can warn us that we are getting a run of extremes and should be concerned by them. As Hansen warned us some time ago, every broken record carries the fingerprint of climate change – not necessarily caused by climate change, but made more likely by climate change.

They can show us, too, how our climate is changing over the long term – and those trends are likely to continue into the future, over at least a similar time-frame. “Climate is what we expect, weather is what we get,” (the quote is well known but its origin is obscure) and in those terms it’s clear that we need to look at periods of more than ten years.

Fortunately, we have done that – well, the BoM has, and has made the data available to all of us online. In particular, their trend maps make long-term changes beautifully (scarily?) clear. Here, for instance are the national rainfall and average temperature trends since 1970.

rainfall-trends

temp-trends

Food for thought – especially the extreme drying trend down the East coast, where most Aussies live. For more detail, follow my link to look into different regions, seasons and data sets.

As for Townsville, all we know is that we don’t know what to expect. The BoM made some educated guesses for the Townsville Bulletin’s January 4 article about our meagre 2015 rainfall but most of the article was concerned with very short-term forecasts. The BoM’s Outlook page suggests that the North will be drier and hotter than average in the next few months, Feb-April, but we shall have to wait and see.