When He and She Look Different; Birds #2

Continuing from last week, which seems to have generated some interest I'm happy to say. I won't reiterate last week's introduction, but will move on to introduce some very dimorphic couples indeed, birds which in at least some cases you'd have to know belonged to the same species. These are not just a question of more and less intense versions of the same colour patterns, but quite different ones. However, having said that, I readily acknowledge that such observations are of necessity subjective, and where one type of dimorphism blends into the other is a very fuzzy line indeed.

Where they are truly distinctive however, and the name is descriptive, as so many names are, it means the bird is named only for the male - keep your eye open for this blatant discrimination as you browse!

Mostly in dimorphic species the male is brightly coloured while his mate is not, but this isn't always the case even in species where the male is the dominant partner in terms of courtship and display (we saw a couple of examples last week where the female was dominant, brighter or bigger). I recently had the pleasure of the company of a pair of birds which demonstrated this impressively, at a beautiful campsite at Gunlom Falls in Kakadu National Park in the Northern Territory.

Shining Flycatcher Myiagra alecto pair, male above, female below, Kakadu NP.
He is the same glorious blue-black below as above.
This monarch flycatcher is generally found near tropical waters, including mangroves and monsoon forests.

 

Another Australian example is that of the widespread, but in most places not especially common, big duck, the Australian Shelduck Tadorna tadornoides; it is not readily possible to state which of the sexes is more brightly coloured - they're just very different!

Australian Shelduck pair, Bethungra Reservoir, New South Wales, male right, female left.
A very poor old pic, my apologies; a slightly better photo of the male below, at Esperance, Western Australia.

 

A related group of birds, the South American 'geese', also have very different male and female plumage, but both are also equally striking.

Above Kelp Geese Chloephaga hybrida, Chiloé Island, Chile and
below Upland Geese C. picta, far southern Chile.
In both cases the males are white and the females are coloured.

 

Other such South American examples can be found among the marvellous hummingbirds.

Green Thorntail pair Discosura conversii, Mindo Valley, north-west of Quito, Eucador; male on the left.

In most of the cases which follow however it's pretty straight-forward - the males have relatively striking colouration and the females are essentially brown, which is an excellent colour to be if you don't want to be noticed while sitting vulnerably on a nest.

Superb Fairy-wrens Malurus cyaneus, male (Canberra) above,
female (Eurobodalla Botanic Gardens, Batemans Bay) below.
One of south-east Australia's best-known and best-loved birds.
Males moult in winter and follow the females into brown obscurity.

 

Many of the Australian 'robins' (which are no more robins than our wrens are wrens!) follow a similar approach. 

Flame Robin Petroica phoenicea pair, taking a break from attacking the invaders in the mirror,
Namadgi NP near Canberra.

Hooded Robins Melanodryas cucullata, central Australia, above and below.
I seem to be incapable of taking a decent picture of this species, but I'll keep trying!

 

The whistlers form another familiar Australian group which shows strong dimorphism.

Rufous Whistler male (Tinbinbilla Nature Reserve near Canberra)
and female (Mt Scoria Conservation Park, Queensland)

Other monarch flycatchers in addition to the Shining Flycatcher featured above show dimorphism, even though the females aren't as strikingly coloured.

Leaden Flycatcher Myiagra rubecula male (Mareeba Wetlands, Queensland) and
female, Namadgi National Park near Canberra, below.

 

Trillers are a group of small cuckoo-shrikes (family Campephagidae) which show strong dimorphism, unlike the larger members of the family.

White-winged Triller Lalage tricolor pair, Longreach Waterhole near Elliott, Northern Territory.
This was part of a large flock moving south to breed - he is still moulting into his full breeding plumage.

Satin Bowerbirds Ptilonorhynchus violaceus, male, National Botanic Gardens Canberra, and
females, Jerrabomberra Wetlands, Canberra.
The day when bowerbirds get their own posting here is surely approaching!

 

Mistletoebird Dicaeum hirundinaceum, male (Milang, South Australia) and
female (Fraser Island, Queensland).
The only Australian Flowerpecker (Family Dicaeidae), whose ancestors arrived relatively recently
here from Asia, but which is now the major vector (spreader) of Australian mistletoes.

 

 

Orange Chats Epthianura aurifrons, Bourke, New South Wales.
Now recognised as being well within the honeyeater family, some of the Australian chats nonetheless exhibit a strong
dimorphism that other honeyeaters lack.

Another group which varies considerably between species with regard to the differences between males and females are the parrots, most of which show no such traits. Some do however.

Superb Parrots Polytelis swainsonii, Canberra, above and below.
A threatened species which flies south from northern New South Wales to breed in woodlands
north of Canberra, but in recent years has taken to feeding in Canberra suburbs, probably prompted by drought.

Red-rumped Parrot Psephotus haematonotus pair, Canberra.
An exquisite little ground-feeding parrot, common in suburban parks.

Red-winged Parrot pair Aprosmictus erythropterus; a glorious parrot found across much of the
tropics and eastern inland Australia, as well as southern New Guinea.

As noted above and last week, ducks are well-represented in lists of dimorphic birds. Here are a couple more strong contenders.

Above Chestnut Teals Anas castanea, south coast New South Wales, and
below, Cinnamon Teals Anas cyanoptera, Arica, northern Chile.

And now that we've returned to South America, let's stay there to finish off today's exploration, beginning with one of the continent's truly iconic birds.

Andean Cocks-of-the-Rock Rupicola peruvianus, males above at a display lek,
female, below, eastern slopes of the southern Peruvian Andes.

 

Austral Negritoes Lessonia rufa, southern Chile, above and below.
These active little ground-feeders are members of the old South American family of tyrant-flycatchers.

   

Thick-billed Euphonias Euphonia laniirostris, Aguas Calientes, below Machu Picchu, Peru, above and below.
Euphonias are members of the huge and colourful tanager family; this species is
found across much of north-western South America.

 

Great-tailed Grackles Quiscalus mexicanus, Puerto Jeli, Ecuador.
These bold urban scavengers are North American blackbirds, whose ancestors arrived in
South America relatively recently, as South America crashed into North America.

 

Finally, trogons are one of the more spectacular bird families, comprising some 40 species across the world's tropical and sub-tropical zones - except for Australia. Many are notably dimorphic.

Masked Trogons Trogon personatus, Andean cloud forests north-west of Quito, Peru.

Well, if nothing else I hope you've enjoyed meeting some pretty impressive birds, with a special characteristic. 

Next time I'll look at a place, probably featuring somewhere from my recent travels in Australia.

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