Unlikely friends: ants and butterflies

Hypolycaena phorbas male
Black-spotted Flash (male) perched on a green-ants’ nest

Walking back down the hill for Tegoora Rock lookout (previous post) I spotted a green-ant nest with – surprisingly – a butterfly perched on it. Living dangerously, surely? Perhaps not.

I had vague memories vague of mutually beneficial partnerships between butterflies and ants so I looked them up when I got home. The butterfly guide books (and sites) generally just note the “attendant ant” species and the food plants, e.g.

The caterpillar is aways attended by the green ants :

It usually hides by day under a leaf, and feeds by night on the leaves, young shoots, buds, and flowers of a wide variety of plants, including :

The Caterpillars pupate on the stems of the food plant, often in groups, head down.

That’s from the Herbison-Evans and Crossley site’s page about the Black-spotted Flash, which they call the Common Tit. (Perhaps it is “common” because it has so many host plants?)

The best short explanation of the relationship’s benefits I found was this:

The butterfly family Lycaenidae (including the Riodinidae) contains an estimated 30% of all butterfly species and exhibits a diverse array of life history strategies. The early stages [i.e. caterpillars] of most lycaenids associate with ants to varying degrees, ranging from casual facultative coexistence [i.e. they help each other but don’t need each other] through to obligate association where the long-term survival of the butterfly is dependent on the presence of its attendant ants. Attendant ants guard the butterflies against predators and parasites during their vulnerable period of larval growth and pupation. The caterpillars, in return, reward the ants by providing attractive secretions from specialized glands in their cuticle.

That’s the introduction to a thesis, Ant Association and Speciation in Lycaenidae (Lepidoptera): Consequences of Novel Adaptations and Pleistocene Climate Changes, by Rodney Eastwood (pdf here). The thesis itself is concerned with tracing associations between ant species, the butterflies they care for, and the butterflies’ host plants; I know a couple of people who would enjoy it but the general idea is enough for most of us.

An article by Eastwood (again) and Ann Fraser in Austral Ecology, “Associations between lycaenid butterflies and ants in Australia,” gives us some statistics:

Nearly 80% of the lycaenid species in Australia, for which the early stages are known, are recorded associating with ants and half of these are obligately ant-associated. … Lycaenids are recorded with five ant subfamilies …  All ant species that tend lycaenids spend at least some portion of their time foraging on vegetation to collect plant and insect nectar.

As I said in an earlier post, male butterflies often hang around their caterpillars’ food plants waiting for females to come and lay eggs, and it is quite likely that the one I photographed is doing just that. And if the ants recognise the caterpillars through chemical cues, the adult probably produces the same cues and will be safe on their nest.

Finally, here is the female of the species, which I photographed at the other end of the Common a few years ago.

Black-spotted Flash
Black-spotted Flash, female

 

Town Common after the floods

Town Common from Tegoora Rock
Town Common from Tegoora Rock lookout

The Town Common wetlands still have a fair bit of open water, two months after our big floods, but it is back to normal levels for this time of year – if there is such a thing as “normal” in our wildly variable climate, that is.

Continue reading “Town Common after the floods”

Birding on the Town Common

On Saturday I was lucky enough to visit the Town Common with a small group which included two keen, knowledgeable birders. Thanks to them, we ended up with a list of more than 50 species from Red-backed Wrens and Spice Finches (10 cm) to Jabirus and Brolgas  (130 cm). We were happy that we spotted so many in just a couple of hours but I should note, just for context, that about 280 have been recorded on the Common.

We drove in past the golf club, visiting Payet’s Tower and the two nominated viewing points on the way to Freshwater bird hide, with a few unscheduled stops as one or another of us spotted birds from the vehicle. There is still a fair bit of open water on the Common and we saw substantial numbers of Magpie Geese, including about 150 in a single flock near the Pandanus viewing point. We briefly visited the Pallarenda Conservation Park, too, adding the Orange-footed Scrub Fowl, Scrub Turkey and others to our list.

Here are some of my photographs from the morning.

Crimson Finch
Crimson Finch, Neochmia phaeton, female

Continue reading “Birding on the Town Common”

The Town Common after rain

I’m not going to claim credit for it, of course, but my post about rainwater tanks was followed almost immediately by the best rain Townsville has had for years, with totals like 250 to 600 mm over a week or so, depending on exactly where you looked. Ross Dam went from about 15% to over 80% – but I will say more about that in another post.

I visited the Town Common yesterday, very briefly, to see the difference the rain had made there. Continue reading “The Town Common after rain”