September 2017.
We needed to be in Goa for a day.
Unfortunately, commitments in Mumbai made it impossible to club a few extra days on either side and so it had to be the early morning flight in and the late night one out.
The plants I had ordered on my previous visit a fortnight ago were doing well and already attracting butterflies. In fact, in the few hours of photography I managed to squeeze in on this ultra short trip, butterfly images outnumbered birds by a comfortable two third majority!
Although I’m reasonably clued-in, I must admit that I am far from expert in wildlife identification. This discrepancy widens ever further when it comes to butterflies. In my defence, these flitters just do not make life easy!
Read on to see what I mean…
The plant in the images immediately above and below is called Crotalaria retusa or rattlepod. It produces toxins that protect it from getting eaten.
A few species of butterflies are immune to these toxins and use them to their advantage. They ingest the toxins and in doing so become unpalatable to birds and other predators.
The rattlepods that were growing wild in the garden were flowering and attracting a number of butterflies including the so called ‘ blue tiger’ cluster of butterfly species: blue tiger, glassy tiger and dark blue tiger (above and below).
From an identification point of view, all look hair-wrenchingly similar.
As ever with Mother Nature, there is always a method in her madness. The similarity between species is known as mimicry and it serves a definite purpose.
Predators discover ‘unpalatability’ the hard way. A juvenile bird needs to prey on one of the butterflies to realise that it is not a safe meal. In doing so it learns to avoids not only that species but all similar-looking unpalatable butterflies belonging to the entire cluster of species as well (Mullerian mimicry).
Some butterflies that do not have the benefit of protective toxins have evolved to appear similar to those that do.
These include the common wanderer (female) and the common mime (both seen below). So, though they may very possibly be scrumptious from an avian point of view, they enjoy protection by mimicking the appearance of the unpalatable blue tigers (Batesian mimicry).
It’s no wonder then, when trying to differentiate between the various species, these butterflies are capable of driving any budding lepidopterists completely nuts !
A large number of birds seen during the recent couple of trips were juveniles (a few shown in the mosaic below, others are featured in the previous post) and one can well imagine the hardships that await them.
Not least of all trying to differentiate a wholesome meal from one that could well be near-fatal.
And, as one of mine own prepares to leave home, I can’t help but wonder if parent birds get as emotionally involved when one of their’s discover their wings…
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