Blue Triangle Butterfly

Well, you asked for photos of the Blue Triangle Butterfly (Graphium sarpedon choredon) - and it obliged by coming back today (another hot day). But you forgot to tell the Macleay Swallowtails (Graphium macleayanum) to stop harassing the poor thing. As a result, you get just some flashes of colour.

There it goes.
Damn! Missed it!
Look for the red oval marker (against the Sassafras tree on the left).

Same image cropped -
the second red ring marks the pursuing Butterfly.

If you bear with me, you will realise that these images, taken together, are clearly identifiable for what they are (which species, I mean).

THE SECOND CHASE

But I want to publish these pathetic images anyway as they show just how hard it is to get a decent shot.
Firstly, the Blue Triangle was either unwilling to sip the nectar from my Buddlejas (but why would it be - when all the other Butterfies in the area want to drink from them?); or was unable to prevent itself from being chased off, by the Macleay Swallowtails.

THE THIRD CHASE
Way off in the distance.

Two Butterflies circling back towards me over my neighbour's
Cypress Hedge - at a distance of about 30 metres.cropped image.
This shows the distinctive triangle patch of colour

The problems experienced by this Butterfly come down to a question of numbers, as I saw only Blue Triangle Butterfly at a time. Therefore the statistical probability is that there was only one individual present in my yard to day.

The other butterflies (of several different species) would total at least 50 individuals at any time (spread over 3 mature Buddleja plants). Of those other Butterflies, the Macleay Swallowtails are the most numerous, and the strongest and fastest fliers, and the most aggressive. The Blue Triangle is an even faster flier then the Macleay Swallowtail, but it was driven off every time it approached the Buddlejas.

After a further change in direction
the two Butterflies nearly crashed into eachother.

As a result, I got only flashes of colour - quite literally - but with such a brilliant blue colour and the shape of the colour patch - the two factors taken together are totally diagnostic.

Here is the cropped version of the previous image
the Blue Triangle is taking drastic evasive action.
Shortly afterwards, it gave up and I did not see it again.

Territorial Behaviour of Butterflies

Many people do not realise how aggressive Butterflies can be towards eachother. If there are many Butterflies around (as I am getting at present), just stand and watch their behaviour for a few minutes, and you will probably recognise this territorial behaviour for what it is.

The second "chase" (by two Macleay Swallowtails) didn't last long, but the third chase - by a single Macleay Swallowtail lasted 90 seconds without a break, and covered a circuit of some 60 metres diameter, with a lot of zig-zagging. As you can see, the chase was very intense, and obviously strenuous.

Given that Butterflies cannot actually attack eachother with weapons (sharp teeth or spurs, as we recognise amongst mammals and birds) I am not sure what they do, other than literally just harass the victim - chasing it away, or probably refusing to allow it to rest on a "Nectar tree" - one where adult Butterflies drink nectar - as distinct from "feed plants" (where the females lay eggs, so that the resultant caterpillars can eat suitable food). Many Butterfly caterpillars are highly specific in their nutritional requirements - e.g., plants of a particular genus or family.

In some species, the "territoriality" is restricted to males guarding territory from other males of the same species.

In my case documented here tonight, it is interspecific, and would appear to be related to access to nectar trees, not a matter of rivalry for mates.