About Me

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Canberra-based naturalist, conservationist, educator since 1980. I’m passionate about the natural world (especially the southern hemisphere), and trying to understand it and to share such understandings. To that aim I’ve written several books (most recently 'Birds in Their Habitats' and 'Australian Bird Names; origins and meanings'), run tours all over Australia, and for the last decade to South America, done a lot of ABC radio work, chaired a government environmental advisory committee and taught many adult education classes – and of course presented this blog, since 2012. I am the recipient of the Australian Natural History Medallion, the Australian Plants Award and most recently a Medal of the Order of Australia for ‘services to conservation and the environment’. I live happily in suburban Duffy with my partner Louise surrounded by a dense native garden and lots of birds.

Thursday, 23 July 2020

Birds of (small) Prey

In my last post I included a photo of a cuckoo-shrike overpowering, after quite a struggle, a big phasmid (or stick insect). In terms of relative sizes of hunter and hunted it's probably the biggest invertebrate prey I've seen consumed, but it made me think of the unimaginable myriads of invertebrates, especially insects, that are consumed by birds around the world every single day.
Here's the picture in case you missed it; a dark-phase White-bellied Cuckoo-shrike Coracina papuensisstruggling to overcome a huge, and presumably pregnant female, phasmid. Nowra, New South Wales.
In this case the energy expended by the bird was considerable - I watched it struggling with the insect for at least 15 minutes - but the reward was very substantial and worth the effort. It would have found its lunch by searching the foliage of eucalypts for the camouflaged insects. Many birds hunt thus, gleaning leaves and branches for prey ranging in size from phasmids, cicadas and crickets to much smaller but more abundant fare.
Female Blue-crowned Trogon Trogon curucui, Muyuna Lodge on the Amazon River,
northern Peru. She has also captured a very large stick insect.

Yellow Wattlebird Anthochaera paradoxa with cicada, Bridport, Tasmania.
Cicadas are smaller than phasmids, probably with more hard indigestible bits,
but tend to be numerous.
However most invertebrates gleaned from foliage are much smaller; as long as these snacks are sufficiently numerous and easy to find, the effort of snapping them up is also rewarded. I am constantly amazed at the number of caterpillars and other larvae that are lurking (and munching) on trees, shrubs and understorey plants, given the number that are eaten daily by birds and the number of chewed leaves that are still in evidence! Here are some efficient caterpillar-eaters, each of which must find many food items of this size every day - and of course far more if they're feeding hungry nestlings.
Male Crimson Chat Epthianura tricolor, Great Victoria Desert, Western Australia.
Fire-eyed Diucon Xolmis pyrope, a tyrant flycatcher which specialises in living in the cold windy
expanses of Patagonia. This one was in Torres del Paine NP in southern Chile
Pallid Cuckoo Cacomantis pallidus, Great Victoria Desert; this caterpillar seems ridiculously small
for the size of the bird, but again there was probably a good supply of them.
Australasian Pipit Anthus novaeseelandiae near Canberra; I'm sure this beakful of caterpillars was
going to feed demanding babies.
Shining Bronze-Cuckoo Chrysococcyx lucidus, Uriarra Crossing on the Murrumbidgee River near Canberra.
That spring there was a major population explosion of these tiny furry caterpillars in the casuarinas along
the river, and many small cuckoos arrived to feed on them. Not many birds can manage
the often irritating caterpillar hairs but cuckoos seem to specialise in them.
Even smaller leaf-eating insects exist, and are also sought by many birds. Lerp is the term used for the larvae of many species of sap-sucking psyllids, which are true bugs (ie Hemipterans) that secrete surplus sugars to form waxy protective coatings. Many birds nip these off to access the insect inside. The most specific practitioners of this feeding method in Australia are the pardalotes, and on a still summer day the pattering of falling lerp covers can clearly be heard. Here are some honeyeaters which also feed on them, though each insect can only provide a tiny reward.
Fuscous Honeyeater Ptilotula fusca Jerrabomberra Wetlands, Canberra.
Hanging upside down is an effective way to access the underside of leaves.

Yellow-plumed Honeyeater Ptilotula ornata, Nundroo, far western South Australia.

Varied Honeyeater Gavicalis versicolor, Cairns Esplanade.
The white material on the underside of the fig leaf above the bird's bill is
probably webbing protecting either caterpillar or spider rather a lerp,
but the foraging strategy is the same.
Finally before moving on from gleaning here is a bird whose prey's identity I'm not certain of. The Crested Shrike-tit Falcunculus frontatus is a powerful-billed gleaner now regarded as the sole member of its family. Normally it rips bark from tree trunks to extract small animals lurking beneath it, but this one was tearing apart a silken 'bag' in Callitris pine woodland.
I suspect the bag contained processional caterpillars (generally well-protected by stinging hairs), but I couldn't confirm that.
Some birds specialise in catching insects in the air, while many others do it opportunistically. It requires great dexterity and skill.
Mixed flock of woodswallows (mostly White-browed and Masked) hunting flying
insects in front of a coming storm, central Queensland.
Dragonflies, though hard to catch, offer good rewards; they are an important part of the diet of Rainbow Bee-eaters Merops ornatus. This species and the next have long slim bills like forceps.
Rainbow Bee-eater with dragonfly, Namadgi National Park near Canberra.
Great Jacamar Jacamerops aureus with unidentified flying prey, Manu Biosphere Reserve, Peruvian Amazonia.
The Australian (and south-east Asian) fantails, Family Rhipiduridae, are mostly aerial specialists, but some species also chase prey along the ground with outstretched wings and tail, which both help with steering and flush insects from the ground.
Rufous Fantail Rhipidura rufifrons, Monga NP east of Canberra.
Grasshoppers, being abundant and often conspicuously moving on the ground, are common victims of perch-and-pounce hunters. Here are some 'late' grasshoppers.
Crimson Chat male, Great Victoria Desert, Western Australia.
Laughing Kookaburra Dacelo novaeguineae, Cape Hillsborough NP, Queensland.
This is a big bird, often claimed as the world's biggest kingfisher; the meal is appropriately large too!
Noisy Miner Manorina melanocephala, a common and pugnacious colonial honeyeater
which is primarily an insectivore, Callum Brae NR, Canberra.

Female White-browed Woodswallow Artamus superciliosus, Karumba, tropical Queensland.
And I think this Yellow (or Green) Oriole Oriolus flavocinctus is about to eat a beetle (despite being mostly a fruit-eater). but it could equally probably have taken it off the ground or gleaned it from foliage.
Yellow Oriole (now often referred to as Green Oriole to avoid claimed confusion with an unrelated and utterly
dissimilar bird from northern South America), Cairns, Queensland.
Other birds extract prey, often wood-boring larvae, especially of moths or beetles, from living or dead wood. Those with finer bills extract their meals from crevices in bark.
Narrow-billed Woodcreeper Lepidocolaptes angustirostris, Chapada dos Guimaraes, western Brazil.
This is one of a very large number of related species in the old South American ovenbird group;
it is clearly a rewarding lifestyle.
White-browed Treecreeper Climacteris affinis near Canberra. Another old Gondwanan,
but not at all related to the woodcreepers; a striking example of parallel evolution.
Grey-crowned Babbler Pomatostomus temporalis, Longreach Waterhole, 700k south of Darwin.
This one was assiduously probing holes in dead wood.
Species with stronger bills simply smash their way into the wood to get their wriggling rewards. Woodpeckers, found in all vegetated continents except Australia, are famed for this. Small holes excavated by these little woodpeckers are obvious in these photos.
Cinnamon Woodpecker Celeus loricatus, Rio Silanche north-west of Quito, Ecuador.
Yellow-fronted Woodpecker Melanerpes flavifrons near Sao Paulo, Brazil.
Bigger woodpeckers make a much bigger mess of the tree however!
Magellanic Woodpecker Campephilus magellanicus excavation, Torres del Paine NP, Chilean Patagonia.
This magnificent bird is up to 45cm long.
They're not the only birds however which demolish wood in the search for big grubs.
Yellow-tailed Black-Cockatoo Calyptorhynchus funereus, tearing a wattle sapling apart to
extract larvae, Murramarang NP, south coast NSW.
Some birds dig into the ground to get their rewards.
Laughing Kookaburra, Rosedale, NSW south coast, whose beak shows how far it has been probing into the soil for food.
Finally for today, while we tend to think of birds hunting in water as primarily interested in fish or frogs, many of them are interested in much smaller rewards and flocks of various waders extract many thousands of small animals from mud, sand and water daily. The principle is much the same whether they are probing into mud or water - they usually can't see what they're doing and rely totally on sensitive receptors in the tip of the bill and the inside of both upper and lower mandibles. These 'touch/taste' receptors (we have no equivalent) are packed in at densities of thousands per square millimetre. When a living organism is sensed (and they can distinguish between live food and inanimate objects) the bill snaps shut. While the moment of capture is beyond my means to photograph, and the prey is usually tiny, here are some practitioners going about their business.
Bar-tailed Godwit Limosa lapponica, Cairns. Note the upturned bill; there are numerous subtly or obviously
different bill shapes among waders to enable many species to feed in the same place while
minimising competition.
Black-necked Stilt Himantopus mexicanus, Galápagos.
Sanderling Calidris alba, also in the Galápagos; it has a much shorter stouter bill.

Immature White Ibis Threskiornis molucca above,
and Yellow-billed Spoonbills Platalea flavipes,
both at Jerrabomberra Wetlands, one of Canberra's premier birding spots.

Ibis and spoonbills are closely related, but while ibis probe into the mud, spoonbills
systematically sweep their bills from side to side in the water, snapping up tiny
organisms as they contact them.
Flamingos achieve the same result, but in a unique and seemingly improbable fashion, with their heads upside down!
American Flamingo Phoenicopterus ruber, Galápagos. This bird is straining the shallow water for
invertebrates (especially shrimps) and algae. Food is separated from water and unwanted items
using a large sensitive tongue with fleshy spines to pump water in and then out again,
sieving it as it goes. This species is found in the Galápagos and the Caribbean.
Crabs are abundant invertebrates in most shore situations, and feature in many birds' diets.
Common Sandpiper Actitis hypoleucos with crab snack, Darwin.
I recently observed a quite different bird enjoying a crustacean meal too, which took me quite by surprise. The light was wrong, but the subject makes it worth while.
Pied Currawong Strepera graculina, dismembering a freshly caught yabby (a common Australian freshwater crayfish),
Cotter River Reserve, near Canberra. I can't readily find other accounts of this.
Shellfish and other snails make a good meal, but require special techniques and strength to extract.
Young Dolphin Gull Leucophaeus scoresbii, Tierra del Fuego, far southern Argentina.
This bird seemed a bit unsure what to do next, but I've watched Kelp Gulls in Chile
repeatedly flying up and dropping heavy shells onto rocks until they broke, and
then extracting the flesh.
Snail Kites Rostrhamus sociabilis on the other hand know exactly what to do with the big Apple Snails
(Pomacea spp.) that comprise virtually their entire diet. The elaborately elongated
slender upper mandible evolved to extract the snail from its shell by cutting the columellar muscle
that attaches the body to the shell; once that is accomplished the snail simply drops out.
This bird was showing its skills in the Pantanal, south-western Brazil.
So, there's an invertebrate for virtually anyone - at least for representatives of just about any bird family you can think of. Apparent declines in insect populations reported from many parts of the world are cause for concern for this reason, as well as many others. Meantime we can just wonder at the largely hidden vast diversity of small life on which millions of birds depend, and at the myriad of strategies developed to this end. It's still a wonderful world.


NEXT POSTING THURSDAY 13 AUGUST.
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Thursday, 9 July 2020

Tapitallee; a yard to remember

Just last week, in the midst of the chaos of the current world, an era came to an end, noticed by only a very few. It was time for Lou's parents to leave their home, which they had built over a quarter of a century ago. I was first welcomed there 17 years ago, and have spent very many happy hours and days there. It is in Tapitallee, a north-western outlier of Nowra on the Shoalhaven River some 100km south of Sydney and about 13km from the sea. Indeed, they were on the very edge of greater Nowra; over the back fence was an old cemetery, and beyond that open country and forested hills. The devastating fires of January came close, but didn't arrive, after many anxious days of waiting and hard work preparing for the worst. 

It was a big house in a big yard, which is 120 metres from front to back and 50 metres across, so some 6,000 square metres (ie 0.6 hectares, or 1.5 acres if you prefer). My favourite part of it was the area of original eucalypts up the back. From the verandah, where we spent many hours drinking coffee, chatting and just watching life go on, I could watch the birds coming and going in those eucalypts, and in the lovely casuarinas and big banksias along the closer boundary. Today I just want to share with you some Tapitallee natural history memories, of which I have many. Firstly here's that 'wild' area up the back. 
A mix of Spotted Gums Corymbia maculata and White Stringybark Eucalyptus globoidea.
Very justifiable concern about fire hazards - this area is to the dangerous west side of the house -
led to the ground being largely cleared of valuable ground litter.
Rough Google Earth sketch map, with key features as decribed here indicated.
 \
A tall hedge of Lilly Pilly Syzygium (or Acmena) sp. grows between the gums above and the house;
from it in good seasons we harvested numerous tiny purple berries from which I made a
very pleasant tangy jam.
I had some hopes of such bounty from the Davidson Plum too (Davidsonia sp, Family Cunoniaceae). We bought it as a seedling at a coastal Saturday market, but I knew it wouldn't thrive in frosty Canberra (it's a rainforest plant from further north) so I got permission to plant it at Tapitallee. For years it struggled and never grew, until it got inadvertently 'weeded' one day. Of course I assumed that was the end of it but astonishingly it resprouted from some root remnants and took off! It's now considerably taller than me.
Unfortunately I'll never taste the plums; it still hasn't flowered, and I'm not even sure that it doesn't need two plants
to form fruit. Hopefully the new owners may get to try them one day.
Just one more memorable plant before I introduce some of the wildlife. 
This lovely Blackbutt E. pilularis is actually just across the road, and perfectly positioned to
glow in the late summer sun. Sadly I seem never to have captured that moment.
Needless to say birds were profuse; over the years I counted 96 species in or over the yard (and a few more in the immediate vicinity). Many were common, others were not; here is one that I only saw once there.
Bassian Thrush Zoothera lunulata, one of Australia's only two native thrushes.
It's not particularly rare, but shy and not always easy to observe. It's certainly
not a common garden bird!
It was always good for pigeons, especially fruit-eaters from nearby rainforest-edge remnants.
Brown Cuckoo-Dove Macropygia phasianella; this one lives along much of the east coast, but doesn't venture inland.

White-headed Pigeons Columba leucomela are also very handsome, and have a similar distribution
along the east coast. They were usually present in the yard or flying through, and their
deep flutey descending 'WOOP woo' was part of the yard's sound track.
Wonga Pigeons Leucosarcia melanoleuca usually walked when visiting; they make their presence
know through much of the day with an incessant high-pitched 'woo woo woo', proclaimed from a perch.
They have a very high boredom threshold and can call for hours!
Eastern Yellow Robins Eopsaltria australis were permanent residents...
... as were the Superb Fairywrens Malurus cyaneus which swarmed everywhere, including
onto the verandah while we were also using it. This is a male in non-breeding plumage
(dark blue tail and black bill).
Parrots and cockatoos were plentiful - ten species in all, including the uncommon and Threatened Glossy Black-Cockatoo, which only came when the casuarinas were fruiting, and fed quietly on the dust-like seeds. 
Glossy Black-Cockatoo  Calyptorhynchus lathami. This is a female, with yellow spotting.
They always hold the cone in the left foot (this picture is a bit ambiguous with regard to that).

Male Australian King-Parrot Alisterus scapularis, a common but glorious visitor.
By their behaviour I'm sure some of the neighbours were feeding them.
Sulphur-crested Cockatoos Cacatua galerita are quite capable of helping themselves; this one was
biting into an only doubtfully ripe orange purloined from a tree in the yard.
And other species only appeared in the warmer months, sensibly spending winter in warmer places further north (though by Canberra standards, Nowra is pretty benign!).

Olive-backed Oriole Oriolus sagittatus. Curiously, when were there recently for the last time,
deep into winter, there was an oriole calling much of the time. It shouldn't have been there then,
and it certainly shouldn't have been announcing its territory in winter!
Yellow-faced Honeyeater Caligavis chrysops chirruping loudly to announce its more conventional return
(compared with the oriole above) at the end of winter. One of the commonest south-eastern migrants.
One of the loveliest of the migrants, and not a common one, is this beautiful Rose Robin Petroica rosea (male above,
female below), which usually passes through in spring and autumn en route to and from the wet mountain forests.

There were other memorable birds too, which I didn't manage to lay lens upon.The first Christmas I went there, there were wonderfully raucous big Channel-billed Cuckoos calling and flying over; I knew then I'd come to the right place! Eastern Whipbirds worked year-round up and down the hedges, and on occasions even hopped onto the verandah. Several times - including right at the end - a rare Square-tailed Kite wheeled over the yard, soaring as it searched for prey, mostly other birds. One night I was aroused by the deep and splendid double note call of a huge Powerful Owl; armed with a good torch I went out and was thrilled to see it high in one of the back Spotted Gums.

There were of course some other vertebrates present.
Water Skink Eulamprus heatwolei, a common skink of south-eastern Australia.
Lesueur's Tree Frog Litoria lesueurii, which we sometimes saw on the windows.
It is also known, evocatively, as the Maniacal Cackle Frog!
But as everywhere, the greatest diversity was in the numerous invertebrates, and while my ignorance of the small hordes is legendary, I learnt a bit by prowling the yard just to see what I could see. And there was usually quite a lot! Here are some of them, with names where I could assign them.

In some summers the cicadas dominated, especially in the eucalypts up the back.

Redeyes and Double Drummers on a Spotted Gum; that year, the summer of 2013-14, was a bumper
year for cicadas at Tapitallee. (More information on that here and here.)

Empty cicada nymph cases; in a good summer there can be hundreds of these on any elevated surface, where the
nymphs have emerged from underground where they feed on roots, and turn to adults.

Redeye Cicada Psaltoda moerens, one of the commonest cicadas in this part of the world, where
the roar of competing males can be quite deafening.

Razor Grinder Henicopsalatria eydouxii; never as common as the Redeyes, and with a harshly metallic call.

Double Drummers Thopha saccata have truly fearsomely loud calls, taking over the world it seems.
Other Hemipterans (ie true bugs) were of course also present.
Like the cicadas this bug lives by inserting its proboscis into plant tissue and extracting nutrients.
However the stem of this developing lemon is considerably softer than eucalypt wood!
If you click on the picture to enlarge it, you can see the proboscis clearly, between the black and white antennae.
Flies are always abundant, and I can only offer (partial) identification for a few of these, but that shouldn't interfere with our enjoyment of them.
Robber Fly (or Assassin Fly) Ommatius coeraebus. These are fierce hunters; this one is watching for
potential prey to fly by. Almost anything can fall victim to them, but other flies, moths and butterflies,
beetles and wasps are common targets.
Bristle Fly, family Tachinidae.
And as I suggested, you'll just have to admire these without a name.
On Spotted Gum bark.
On the Davidson Plum featured above; I love its iridescence.
Moths and butterflies are everywhere, though I don't always have much luck in photographing them. Here are a few that cooperated.
Brown Ringlet Hypocysta metirius, a common east coast species (as any insect that I can identify is likely to be!).
The caterpillars depend on a range of native grasses and sedges.

,
Hawkmoth, Family Sphingidae.
These fast-flying moths are said to be the only insects other than hoverflies which can hover at flowers.
Male Orchard Swallowtail Papilio aegeus, a large and familiar garden butterfly the female of which lays
its eggs on citrus plants, both native and garden species.

Tailed Emperor Charaxes (Polyura) sempronius; the photo doesn't do this handsome butterfly proper justice.
I'm calling this a 'tent caterpillar', but I don't think it's one of those normally so designated.
I'd be glad of any assistance.
And some representatives of several different groups.

Blue-eyed Lacewing Nymphes myrmeleonoides, Order Neuroptera.
The white wingtips are good identifiers.
A long-horned grasshopper or katydid.
A tiny native bee, already laden with pollen, about to alight on a passionfruit flower.
For some reason these flowers never did produce fruit, but they were great for attracting insects!
 
An adventurous night slug; it had reached the bottom of the stem and was about to head up again.
Titan Stick Insect Acrophylla titan, the second-largest stick insect in Australia, it
can be almost 30cm long. This one wasn't quite that size, but still pretty impressive,
and superbly camouflaged.
An insect this size is bound to attract predators, and this next stick insect (or phasmid) - almost certainly a female full of eggs - was a meal worth the considerable efforts of this (locally uncommon) White-bellied Cuckoo-shrike.
I only saw this bird twice in my times at Tapitallee; the size of the insect can be assessed
when you know that the bird is around 25cm long.
It's a story, albeit a very dramatic version of it, that is repeated many times a day in an environment like the Tapitallee yard.
A bristle fly, family Tachinidae, and I'm going to venture to suggest Amphibolia sp., that didn't make it.
A place that rich in insects is also going to be rich in spiders; to start with, here are a couple of House Spiders (Badumna sp.) which were busy with their own Christmas dinners above our heads on the verandah ceiling a few Christmases ago.
Christmas Beetle, Family Scaribaeidae, dinner (appropriately!) above, and
click beetle, Family Elateridae, below.
 


St Andrews Cross Spider Argiope keyserlingi; the 'ribbons' in the web reflect UV light,
which attracts flying insects to flowers.

Triangular or Crab Spider Arkys lancearius Araneidae awaiting breakfast with open arms;
it is considerably less than 10mm long.
Orange-legged Swift Spider Nyssus coloripes (formerly Supunna picta).
They shelter in webs, but tend to chase their prey down.
But of course predators often become prey, as befell this unfortunate - or unwary - wolf spider.
The wasp has paralysed the spider (you might need to magnify the picture by clicking on it)
and is taking off to be devoured by its hatchlings in a burrow in the lawn. Drama is everywhere.
Any yard has life, pulsing and teeming, changing with the seasons. Our Tapitallee yard was bigger than many, had many native plants and lots of cover, and was not far from Tapitallee Nature Reserve. All this helped but it was special mostly because we spent a lot of time watching it and recording some of it. I hope you've enjoyed this small tribute to a  place that was, and always will be, an important part of our lives. I also hope it serves as a reminder that any yard, for those of us fortunate enough to have one, or nearby open space, is a good place for wildlife.

NEXT POSTING THURSDAY 23 JULY.
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