The short days and cool weather of our winter don’t stop our butterflies completely but do slow them down. Numbers drop off, and their hours of activity shrink. As I noted years ago, most of them find quiet spots by about 3.30 each afternoon where they can rest safely until the temperature climbs again on the following morning. The one in my photo is doing just that, but I only spotted it because I saw it land.
Do butterflies really sleep?
As this site says, it “depends on your definition of sleep. If you want to define sleep as an inactive, low metabolic state: yes. This low metabolic state is often driven by the temperature in the air.” Butterflies are ectothermic (“cold-blooded”, except that they don’t really have blood) so they need external warmth for their activity.
An extension of their overnight “sleep” is the over-winter hibernation which carries adults of some species through a long period of low temperatures and limited food supplies, even here in the tropics.
Winter arrived yesterday, with its usual suddenness.
As in most years, a big weather pattern somewhere down South pushed cold, dry air from Central Australia out over the ranges to Townsville. Overnight temperatures dropped, and the humidity crashed. Last year I reckoned the Dry arrived at the end of April, as it did in 2014 and 2015 so we’re running a couple of weeks late this year.
In numbers, the changes are from overnight minimums of 18 – 21 C for the beginning of May down to 13.4 and 10.6 on the nights of the 12th and 13th, and humidity from 55 – 90% down to 16 – 19%.
In daily life that means the cat becomes a permanent lap-rug, if he can get away with it, but we’re not permitted to stroke him because sparks leap painfully from the tips of his ears and tail. Meanwhile, we search for windcheaters we haven’t worn for six months and seek out patches of sunshine in the morning instead of drifting automatically into shade.
Let me be clear, however: I am not complaining. I love this weather, and after a good Wet season I really look forward to it.
There was an extraordinary whooping commotion in our poplar gum just on dusk yesterday. It sounded like Friarbirds on steroids or half a dozen Blue-winged Kookaburras on helium – a huge sound!
I ducked outside straight away to see what on earth was going on and spotted two big grey-brown birds high in the tree (and there may have been more hidden amongst the leaves). They were Channel-billed Cuckoos, Scythrops novaehollandiae. Continue reading “Channel-billed Cuckoo in town”
Around this time every year our huge poplar gum bursts into flower, producing a bonanza for the birds which come from miles around to feast on its nectar. We delight in the display, too, even while we deal with the mess the tree and the birds make. Thousands of flowers pop their caps, which litter the lawn like miniature caltrops, then the rainbow lorikeets arrive to squawk and squabble, Continue reading “Bonanza!”
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.