Thursday, October 29, 2009

BIRDS - RAINBOW LORIKEETS

Rainbow Lorikeet

Trichoglossus haematodus
Psittacidae

Rainbow Lorikeets are widespread in eastern and northern Australia, and also around Perth. Separated from their natural range by thousands of kilometres, the feral Rainbow Lorikeets of Perth had become established by the late 1960s. In the 1980s, the population expanded. The problem with Rainbow Lorikeets in Perth is that they are aggressive around nesting hollows, preventing native birds from nesting. They have even been recorded dragging the nestlings of Australian Ringnecks from hollows and dropping them onto the ground, then occupying the hollow themselves.

Description

The Rainbow Lorikeet is unmistakable with its bright red beak and colourful plumage. Both sexes look alike, with a blue (mauve) head and belly, green wings, tail and back, and an orange/yellow breast. They are often seen in loud and fast-moving flocks, or in communal roosts at dusk.

Similar Species

Rainbow Lorikeets are such colourful parrots that it is hard to mistake them for other species. The related Scaly-breasted Lorikeet is similar in size and shape, but can be distinguished by its all-green head and body.

Feeding

The Rainbow Lorikeet mostly forages on the flowers of shrubs or trees to harvest nectar and pollen, but also eats fruits, seeds and some insects.

Breeding

The eggs of the Rainbow Lorikeet are laid on chewed, decayed wood, usually in a hollow limb of a eucalypt tree. Both sexes prepare the nest cavity and feed the young, but only the female incubates the eggs.

Saturday, October 24, 2009

Manta Ray 091023

Manta rays are found in temperate and tropical waters near continents and island groups of all oceans. These cartilaginous fishes have greatly extended, wing-like pectoral fins.

The Atlantic manta is characterized by a pair of forward-pointing lobes on each side of the head, with a supposed resemblance to a devil's horns. These lobes are used to guide plankton and small crustaceans into the fish's mouth as it cruises near the surface; dense gill rakers extract the plankton. The fish is harmless to humans, but its thrashing when caught can be dangerous.

The following video was taken snorkelling about 10 metres off the south end of Terrigal beach, NSW, Australia near the rock pool.



Scientific classification: Manta rays belong to the family Mobulidae. The Atlantic manta is classified as Manta birostris.

BIRD - BLUE-WINGED KOOKABURRA


Blue-winged Kookaburra

Dacelo leachii
Halcyonidae

Though the Blue-winged Kookaburra is only slightly smaller than its more famous relative, the Laughing Kookaburra, it is, nevertheless, one of the world’s largest kingfishers. Blue-winged Kookaburras inhabit northern and north-eastern Australia, and this range overlaps with that of the Laughing Kookaburra in northern and eastern Queensland, where both species may inhabit the same forests or woodlands. Both emit a loud, raucous cackling call that has been described as ‘extended maniacal laughter’, but, alas, the Blue-winged Kookaburra’s laugh is said to ‘lack the same sense of humour’.

Description

The Blue-winged Kookaburra is a large kingfisher with a big square head and a long bill. It has a distinctive pale eye. The head is off-white with brown streaks, the shoulders are sky blue and it has a uniform blue rump.The throat is plain white and the underparts are white with faint scalloped orange-brown bars.The back is mid brown. Males have a dark blue tail while females' tails are barred red-brown or blackish. Otherwise the sexes are similar. The legs and feet are grey and the bill is dark above and yellowish below. Juveniles have paler streaks on the head with darker mottlings. There is slight geographical variation with plumage more buff in north-western Australia (race clifoni). The Blue-winged Kookaburra is also known as the Barking or Howling Jackass or Leach's Kookaburra. As they are shy and often quiet in the foliage they may be overlooked.

Similar Species

The Laughing Kookaburra, D. novaeguineae, is slightly larger with a slightly longer bill.The Blue-winged Kookaburra also has a head that is streaked white with a white rather than dark eye and no dark patch behind the eye. The Blue-winged Kookaburra has a bright blue wing patch and rump. The call is also quite different.


Feeding

Blue-winged Kookaburras eat a wide range of invertebrates and vertebrates. They consume mainly insects, reptiles and frogs in the wetter months, and fish, crayfish, scorpions, spiders, snakes, earthworms and small birds and mammals at other times. After a controlled dive with their bill open, food is grabbed from the ground. The bill has a special groove near the end of the upper mandible which helps in holding prey. After returning to a perch, the prey is beaten and then swallowed. They show extra care when snakes are the prey. Pellets of undigested items are regurgitated and found beneath daytime perches, roosting sites and nests.

Breeding

The nest site of the Blue-winged Kookaburra is mostly high (to about 25 m) up in natural tree hollows, sometimes in tree termite nests, or in a hole cut into the soft wood of a baobab tree. Typically, the floor of the chamber is lower than the entrance, with an overall length of 50 cm. The breeding pair share the incubation of the eggs and subsequent feeding, which extends for one to two months, and are often assisted by auxiliaries (helpers), mainly from the previous year's clutch.