Common Crow Butterfly

This butterfly is as common as crow. It is also not afraid as none of the birds want to taste this butterfly which is full of alkaloid imbibed during its caterpillar stage of life. Yesterday evening it had stopped raining. So taking my gears I ventured out in my garden to find any good critter to shoot. This Common Crow (Euploea core)was very friendly and allowed me to take very closeup shots. All shots were taken using Canon EOS 5D mark II with Canon EF 100mm f/2.8 USM Macro using Canon MT-24EX macro twin light flash.

The Common Crow (Euploea core) is a common butterfly found in South Asia. In India it is also sometimes referred to as the Common Indian Crow, and in Australia as the Australian Crow. It belongs to the Crows and Tigers subfamily of the Nymphalidae (Brushfooted butterflies).

The Common Crow is the most common representative of its genus Euploea. Like the Tigers (Danaus spp), the Crows are inedible and thus mimicked by other Indian butterflies (see Batesian mimicry). In addition, the Indian species of the Euploea genus shows another kind of mimicry, Müllerian mimicry. Accordingly, this species has been studied in greater detail than other members of its genus in India.

Common Crow on Tridax Daisy

The Common Crow (Euploea core) is a glossy black butterfly with brown underside with white marks along the outer margins of the wing. The wingspan is about 8-9 cm and the body also has prominent white spots.

Upperside dark brown, broadly paler along terminal margins; Fore and hind wing with subterminal and terminal series of white spots; on fore wing the former more or less oval, curved inwards opposite apex, the latter series often incomplete, not reaching apex, the spots smaller; often there is a small costal spot, and very rarely a spot in apex of cell and one or more discal spots; on the hind wing the inner series of spots are elongate, the outer conical. Underside similar, but ground-colour more uniform; cell, costal and discal spots on both fore and hind wing nearly always present.

Common Crow on Tridax Daisy

Fore wing subtriangular, tornus more rounded than in E. core. Hindwing broadly ovate. Upperside dark brown, broadly paler along the terminal margins, especially on the fore wing. Fore wing with more or less incomplete and obsolescent series of subterminal and terminal small white spots, and a powdering of violaceous-white scales at apex, varying very considerably in extent from a mere trace of violaceous between the veins to a large and very conspicuous patch occupying the whole of the apex. Hind wing with a subterminal series of oval or inwardly conical and terminal series of more rounded white spots. Underside paler brown, the white spots larger, more clearly defined. Fore wing not violaceous at apex, a spot (sometimes absent) in apex of cell, and two or three discal spots. Hindwing: a spot in apex of cell, also sometimes absent, and a discal series of five small spots beyond. Antennae, head, thorax and abdomen very dark brown, and, the antennae excepted, sparsely spotted with white.

It is found everywhere in India right up into the mountains till 8000 feet. Occasionally it swarms in the low, wet, jungles of South India due to the abundance of its foodplants which are spread over three orders of plants.

The butterfly, being protected by its inedibility, has a leisurely flight. It is often seen flying about shrubs and bushes in search of its host plants. It visits a large variety of flowering plant species.

On hot days large numbers of these butterflies can be seen mud-puddling on wet sand. This butterfly also gathers on damaged parts of plants such as Crotalaria, Heliotropium to forage for chemicals precursors to produce pheromones.

Along with other Danaids such as the Tigers, the Common Crow is one of the most common migrating butterfly species. Males and females in equal proportions have been seen to migrate.

Common Crow Closeup

Protection: The Common Crow is distasteful due to chemicals extracted from the latex of the food plants consumed in their caterpillar stage. Thus protected, they fly in a leisurely manner, gliding skillfully with wings held slightly above the horizontal. This indicates its protection due to inedibility to a predator. The inexperienced predator will try attacking it, but will learn soon enough to avoid this butterfly as the alkaloids in its body cause vomiting.

The butterfly has tough, leathery wings. When attacked it shams death and oozes liquid which causes any predators to release them. The butterfly thus has the ability to recover ‘miraculously’ after the predator thinks it has been killed.

Mimicry: The protection mechanisms of the Common Crow, as of the other Danaids, and indeed of all unpalatable butterflies, result in predators learning this memorable aspect at first hand. Predators soon learn to associate the patterns and habits of the butterfly species with unpalatability and to avoid ingesting them in future.

This advantage of protection has led to a number of edible butterfly species, referred to as the mimic, evolving to resemble the inedible butterfly, which is referred to as the model. The resemblance is not only in butterfly markings, but also in behavioural and flight patterns. This form of mimicry where an edible species mimics an inedible species is called as Batesian mimicry.

The mimics can resemble the models very closely. In some cases, it requires hand examination and reference to field guides to tell them apart. The Common Crow is a good example, being mimicked by the following butterflies:

• Common Mime(Chilasa clytia) form dissimilis, both male and female.
• Malabar Raven(Papilio dravidarum), both male and female.
• Common Raven(Papilio castor), female.
• Great Eggfly(Hypolimnas bolina)), female.
• Ceylon Palmfly(Elymnias singala) male and female. (Not in India).

The genus Euploea also exhibits Müllerian mimicry. In this form of mimicry, the members of an inedible group of butterflies find it to their advantage to resemble one another so that their recognition by possible enemies is much easier. Besides this genus, the Blue Tigers (of the genus Danaus) also exhibit this form of mimicry in India.

Juvenile Common Wolf Snake

I found this 20cm long juvenile common wolf snake (Lycodon aulicus) at my hospital. I had tough time identifying it as it did not have the distinctive white bars which wolf snakes have. My good friend Sharath B.K was kind enough to identify it for me. I used Canon EOS 5D mark II with Canon EF 100mm f/2.8 USM Macro using Canon MT-24EX macro twin light flash.

Characteristics: A small, broad and flat snouted snake. It has a constricted neck and a muscular, cylindrical body that gradually tapers towards the tail. The colouration of this snake may vary with its wide habitat. The stereotype dorsal colour for this snake is chocolate brown with yellow transverse stripes. Nearly all varieties have a brown underbelly. Most specimens found in Sri Lanka have a dark brown dorsal colouration and well defined white stripes.

Behaviour: A strict night hunter, being nearly inert by day. Upon nightfall this snake bursts into action. It prefers low vegetation close to human dwellings for they harbour its most preferred food, lizards in large numbers. This snake often enters houses in search of geckos and often stumbles upon an unsuspecting human. This snake instinctively flees if disturbed by a human but attacks viciously if barred of all opportunity of escape. The fine teeth of this snake often inflict serious injury. During the day it remains coiled up and will only hide its head amidst its coils if disturbed.

Food: This snake feeds mainly on lizards and frogs.

Juvenile Common Wolf Snake Closeup

Breeding: Due to the wide distribution of this snake its reproductive habits vary considerably. In most areas which receive rain during the southwest monsoon and in Sri Lanka the mating season for this snake lasts from November to January. In other areas this takes place between June and August. The exact period of gestation is not precisely known and seems to vary according to the external conditions. Usually the eggs are laid in February and most possibly the young hatch out in late April or early May before the onset of the monsoon. The clutch is usually within the limits of 4 and 7 but older females may lay up to 11 eggs at a time. The oval shaped eggs measure on average 30mmx11mm.

Growth: During the moment of hatching the young measure around 150mm in length. The new hatchlings jump start into action and begin to feed voraciously on lizards. These snakes reach maturity after two years and females are capable of reproducing once 45cm long. Females grow longer than males. Females may reach lengths in excess of 70cm while males seldom grow longer than 55cm.

Male Giant Crab Spider

Today for breakfast I had a house guest in my kitchen. A Male giant crab spider also known as common house spider(Heteropoda venatoria), huntsman spider, banana spider (due to its occasional appearance in marketed bananas) appeared over a kitchen tile. He was a huge guy, body around 3 inches in size. He was patient enough to give me several of his nice poses as he was cleaning his fangs with his palps. I unhurriedly took several of his great shots using my trusty Canon EF 100mm f/2.8 USM Macro on my Canon EOS 5D mark II. Here are 3 shots one full body and other head shot for your appraisal. The background you see is the yellow kitchen tile. These spiders belong to family Sparassidae.

Male Giant Crab Spider closeup

Giant Crab Spiders get their name by waiting for prey to come close, and like lions, chase their prey for short distances. Contrary to their gangly and cumbersome appearance, these spiders are very fast and are able to chase down their prey with ease. These spiders are extremely aggressive, will arch up to make displays to frighten off perceived threats, and will tenaciously cling to attackers or perceived attackers if they think it will protect them. Given any other circumstance, these spiders are designed to slip through holes and cracks and will escape if they feel outmatched.

Male Giant Crab Spider Close up

Huntsman Spiders are not harmful to humans, and although big and scary, are certainly not strong enough to carry off or take a bite out of a human. They will bite in self-defense, in which case they are not venomous, and the only result will be a big red spider bite. As mentioned before, they do cling if picked up, and will most likely bite, making a close-up Huntsman encounter a frightening and potentially painful one, but ultimately not life-threatening. These Spiders mainly eat insects, other spiders and sometimes small lizards and snakes.Big enough Hunstmen might kill and digest very small rodents.

Ever seen Arachnophobia (1990) with Jeff Daniels and John Goodman? It also starred an unnumbered cast of Delena cancerides, aka Avondale Spiders. These little, harmless, yet ultimately frightening spiders are Family Sparassidae (same family as our Giant Crab Spider) and come from Australia. They were “trained” by an entomologist to move through and into scenes on cue using hair dryers to goad them along. Note: The big spider in the movie is actually a species of tarantula. They eat birds among other things but are relatively harmless to humans.