Common crow
Euploea core, the common crow, is a common butterfly found in South Asia to Australia. 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 Danainae (tribe Danaini).
E. core is a glossy-black, medium-sized 85–95 mm (3.3–3.7 in) butterfly with rows of white spots on the margins of its wings. E. core is a slow, steady flier. Due to its unpalatability it is usually observed gliding through the air with a minimum of effort. As caterpillars, this species sequesters toxins from its food plant which are passed on from larva to pupa to the adult. While feeding, it is a very bold butterfly, taking a long time at each bunch of flowers. It can also be found mud-puddling with others of its species and often in mixed groups. The males of this species visit plants like Crotalaria and Heliotropium to replenish pheromone stocks which are used to attract a female during courtship.
The common crow is the most common representative of its genus, Euploea. Like the tigers (genus Danaus), the crows are inedible and thus mimicked by other Indian butterflies (see Batesian mimicry). In addition, the Indian species of the genus Euploea show another kind of mimicry, Müllerian mimicry. Accordingly, this species has been studied in greater detail than other members of its genus in India.
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TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
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OviparousOviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
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starts withThe common crow is a glossy-black butterfly with brown undersides 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 hindwing and can be seen only when the butterfly is captured and observed closely.
Excerpt from Fauna of British India: Butterflies, volume 1:
E. core can be 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 (8,000 ft). 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 holds its wings at an 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 mud-puddler 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 and 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.
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 skilfully 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.
