Common Crow

Appearance

The Common Crow is a glossy black butterfly with brown underside with white markings along the outer margins of both wings. The wingspan is about 8–9 cm and the body has prominent white spots. The male has a velvety black brand located near the rear edge on the upperside of the forewing. On the underside there is a white streak in the same location. This white streak is present in both male and female. In its natural position this streak is hidden behind the hind wing and can be seen only when the butterfly is captured and observed closely.

Status

Very common.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 and become nauseous. Once released the butterfly "recovers miraculously" and flies off. Predators experience enough trauma that the characteristics of the butterfly are imprinted in memory.

Habitat

It is found in southern Pakistan, Sri Lanka, India, Bangladesh, Myanmar, Russia, and Australia.

In its range E. core is found at all elevations, right from sea level up into the mountains to 2,400 metres. It can be observed in all layers of vegetation and in all types of regions from arid land to forested areas. It can as commonly be seen gliding over the treetops as flitting about a foot off the ground searching for nectar flowers. In thick forests it is often seen moving along open tracks or following the course of a river.

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. When gliding E. core helds its wings at a angle just greater than the horizontal plane, maintaining its flight with a few measured wingbeats.

E. core is a nectar lover and visits flowers unhurriedly. It seems to prefer bunches to individual flowers. When feeding the butterfly is unhurried and is not easily disturbed. It can be approached closely at this time.

On hot days large numbers of these butterflies can be seen mud-puddling on wet sand. E. core is an avid mudpuddler often congregating in huge swarms along with other Euploea species as well as other Danaids.

This butterfly also gathers on damaged parts of plants such as "Crotalaria", "Heliotropium" to forage for pyrrolizidine alkaloids which are chemicals precursors to produce pheromones. During courtship the males of E. core release these sex pheromones to attract females. Once a female is in the vicinity the males glide around and with the help of a couple of yellow brush like organs extending out from the tip of the abdomen they disperse the scent in the air.

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

Reproduction

Eggs are laid on the underside of young leaves of the host plants. The egg is shiny white, tall and pointed, with ribbed sides. Just before hatching the eggs turn greyish with a black top.

Food

The Common Crow feeds on a large number of plants of the families "Apocynaceae", "Asclepiadaceae", "Moraceae", "Rubiaceae", "Ulmaceae" and the specific species are "Aphananthe cuspidata", "Asclepias curassavica", "Asclepias guadeloupe", "Asclepias syriaca", "Calotropis gigantea", "Carissa ovata", "Cerbera manghas", "Cryptolepis pauciflora", "Cryptolepis sinensis", "Cryptostegia madagascariensis", "Cynanchum carnosum", "Ficus benghalensis", "Ficus benjamina", "Ficus hederacea", "Ficus microcarpa", "Ficus obliqua", "Ficus pandurata", "Ficus platypoda", "Ficus pyriformis", "Ficus racemosa", "Ficus religiosa", "Ficus rubiginosa", "Ficus variolosa", "Gomphocarpus fruticosus", "Gymnanthera oblonga", "Hemidesmus indicus", "Holarrhena pubescens", "Hoya australis", "Ichnocarpus frutescens", "Marsdenia australis", "Marsdenia rostrata", "Marsdenia suaveolens", "Nerium indicum", "Nerium oleander", "Parsonsia alboflavescens", "Parsonsia straminea", "Plumeria acuminata", "Sarcostemma australe", "Secamone elliptica", "Streblus asper", "Toxocarpus wightianus", "Trachelospermum bowringii", and "Tylophora indica"
...snipped....

It usually has some preference for certain species in a given area. The more commonly used plants are "Ficus racemosa", "Nerium oleander", "Nerium odorum", and "Cryptolepis buchananii". "Ficus pumila" a cultivated garden plant which climbs on walls has also been noted.