A true Tawny Frogmouth

A truly red/rufous coloured Tawny Frogmouth found in Canberra - a victim of road kill

It was wet with heavy rain last night, and all day today, and when I drove into town in the morning I saw a dead bird lying in the cycle lane. It looked like a Boobook, the common local owl in Canberra, but it didn't look right for one. So I took note of where it was in order to check it on my return. Maybe it was something else, what? Then an hour later, as I approached the bird from the other direction, I saw straight away that it was a Tawny Frogmouth, but it was so red, and that is why I hadn't recognised it first time. Although I study these birds and have seen hundreds of individuals, none have been as red as this bird.

All the frogmouths I have seen in the Canberra area have, despite their name, been predominately grey. The males have, if any, only a little red on the sides of their face or a touch on their wings coverts. The females are usually more rufous in the same parts, and a few have a bit more red on their wings, but none I have seen have been so red as this bird. I would so much have liked to have met her when alive in the bush.

The whole of her upper body was red
 apart from her primary and secondary feathers which were dark brown/black

The bird's body was in good condition apart form the obvious head injury that killed her outright. So I gathered her up and took a few measurements for my own records. Her corpse is now in the freezer and on Monday I shall deliver her to the Australian National Wildlife Collection, which is conveniently held by CSIRO here in Canberra, the national capital.

I must look up the type-specimen of Tawny Frogmouth one day to see whether that bird was truly tawny, or grey like most in south-east Australia.

She still had a recently caught moth in her bill when she died

The moth was large, with a body about 8-9 cm long, and grey overall with no particularly obvious features. If anyone has an idea of what it might have been please drop a note. It was obviously too large a prize for the bird to ignore as she risked the traffic to catch it. Let that be lesson to us all: take care on the roads especially while there is heavy rain.

Night watch

An adult female Tawny Frogmouth perched beside her two chicks

Now that the last summer moon is waxing to almost a quarter, it is possible to go out at night and watch the local wildlife without the aid of torchlight. I don't use spotlamps to watch animals as they ruin our night vision, and probably wreck their eyesight too. All we can see is whatever is within the light-zone, outwith that, all is black, darker than if not using a light at all. It is much better to go out at dusk and gradually let your eyes become accustomed to the dark. Anything more than a quarter moon is enough to see under and when there is a full or nearly-full moon I even use binoculars as there is enough light.

The adult delivers a grasshopper to one of the chicks

So, over the past few evenings I have been out watching a family of Tawny Frogmouths with two recently fledged chicks. These youngsters will still be dependent on their parents for about a month after leaving the nest. Frogmouth families typically all roost together during the day, then at dusk the fledglings flit to an open branch, and the adults soon begin bringing food to them. The birds leave their roost about half an hour before full darkness and it is in that first half-hour they are most active. These two adults delivered about ten items per hour for the first hour, mostly within the first half-hour. In the following hour there were no feeds and the two chicks went quiet, snuggled up together and seemed to go to sleep. Not too surprising as the prey items were mostly large grasshoppers which would have probably been more than enough to satisfy the chicks' appetites.

I last saw the adults fly off, presumably to find food for themselves before they would come back and gave the chicks more food. I have used camera traps before to monitor their food delivery times throughout the night and the pattern seems to be; they will bring occasional items during the rest of the night then a few in quick succession as dawn approaches. As with most nocturnal animals, they are more active around dusk and dawn, so those are the best times to watch for them.

At night, Tawny Frogmouths seem to become different birds from the shy ones we see by day. They are so confident under darkness and they do not seem to fear humans. Not only do they allow close approach, but I have had birds fly down to catch insects at my feet (probably stirred up by me) then carry them off to their chicks sitting on a branch a few metres away. Those are the special wildlife moments which we keep in our minds forever.

The two fledglings snuggled up together, head to tail.

Last chicks fledged

A family of Tawny Frogmouths sitting quietly in a tree. As they are nocturnal, they roost by day, relying on their cryptic plumage and minimal movement for concealment from potential predators such as Brown Goshawks. 

The last broods of Tawny Frogmouth Podargus strigoides chicks have finally fledged almost three months after the first broods to do so on 25th October 2014. These final broods fledged on the 16th and 17th January; a brood of one and the other of two, both were from relaid clutches after the adults had lost their first clutches. The pair who finally reared the single chick lost two previous clutches in separate nests to predators unknown (likely Brush-tailed Possum Trichosurus vulpecula). They built a new nest in another tree after each time the eggs were taken, while the pair who reared the twins lost their first brood of chicks after they had left the nest too early. That was possibly after the nesting birds were attacked by a predator, but as these birds are not under constant monitoring, and there was no evidence, we'll never know. They re-used the same nest for their second clutch.

The adult female is on the far left (she has reddish markings on her wings), then the male and two still partially fluffy chicks. Frogmouths usually adopt a 'stick pose' if a potential predator approaches such as a human, but these birds have seen me so often, they know me and here have only partially adopted that pose.

Now that the final results are in I have calculated the breeding success of the sample of Tawny Frogmouth pairs that I study here in Canberra, Australia. I monitored 48 territories this year, similar to most recent years, and most successful pairs (23) reared two chicks, 7 reared three, 8 reared one, another 8 reared none and there were 2 single birds; one male and one female - pity they never met up.

This chick, like so many young fledgling frogmouths, has yet to learn to adopt a protective pose like its parent, in this case mum. Her plumage colouring and posture conceal her well, but I have seen better (see some older posts).

The figure of 17% of pairs not rearing any chicks might seem a high failure rate, but I have recorded almost twice that one year. Overall the breeding success of the population (and that is what matters as all animals must eat to live, including predators) was above average with 1.6 chicks fledged per pair (avg. 1.4), or 1.9 per successful pair (avg. 1.8).

The adults close their eyes and watch one's approach through narrow slitted eyelids. That conceals their bright yellow irides which would betray their camouflage. This chick however, just cannot resist peeping around the branch to watch me with partially open eyes. It will soon learn how to behave safely.

So that ends my study season of Tawny Frogmouths for 2014. It seems a long time since the birds first began building their nests in late July, and it won't be long before July comes around again. For further details of the frogmouths over the season and in previous years click on the links to the right of the page.

What wonderful days and nights I have had with them - great birds.

The male was perched in an adjacent tree, unobtrusive and inconspicuous.

Hot Frogmouths

The youngest fledgling was on the same branch as its parents

There were some hot days in Canberra during the past week and the birds were feeling the heat. While I was checking on the fledging success of the Tawny Frogmouths in my study, I took a few shots of this family as they know me well and are quite confiding. The adults and the youngest chick were on one dead branch and the other two chicks were up in a nearby tree. The threesome were more discrete, the two others were a bit obvious as their white downy juvenile belly plumage was a bit of a giveaway when seen from below. Fortunately most predators would approach from above, especially Brown Goshawks, so they would be less obvious to them.

The chick was snuggling into its father's shade to escape the beating sunshine

Although the dead branch was a good place to sit for concealment, with their superb cryptic plumage, the open branch was exposed to the sun and the chick there was feeling hot. It was sitting close to its father who shielded it from the direct sunshine. All the birds were fluffing open their feathers and holding their bills open to cool down. This showed off the size of those big wide beaks - rather impressive.

All of the family were gaping wide to cool down - this is mum

The young birds had left the nest a few days before and they could fly quite well, enough to flutter from tree to tree and they were now over a hundred metres from the nest. They would still be dependent on their parents for food though, for another few weeks at least while their feathers fully develop and they gain stronger flight muscles.

The two older fledglings were sitting in a nearby tree - growing feathers are heavy as the quills are full of blood, so this bird is relieving the strain of their weight by drooping a wing

Tawny Frogmouth fledglings

Three Tawny Frogmouth fledglings gather on one branch

Most of the Tawny Frogmouths in Canberra now have fledged young and I have been out watching them, to count the prey brought to the chicks by the adults. Although they have left the nest they are still very dependent on the adults, as they will be for about a month. This brood of three roosted during the day in separate trees then gathered in one after dusk when the adults began bringing in food.

The adult female brings in food 

The adults fed the chick which begged loudest first, not that their begging calls are loud. This is more of a rough rasping, coughing call, not shrill like that of most diurnal species' chicks. This is probably an adaptation to reduce the risk of attracting nocturnal predators such as owls which can detect prey by listening for such sounds.

The adult male lands with more food - one chick is fed a t a time, while the others watch on

The adults brought in food every few minutes for the fist hour, then gradually reduced this as the fledglings eased off their begging. Slowly they settled down and remained still most of the time apart from occasional wing stretching exercises. I could tell when an adult was approaching with food as the chicks would see them coming before me and begin fidgeting and calling again.

I use flash to photograph the prey which I can identify later at the desk

I watched under the light of the full moon and I could see the adults hunting not far off as my eyes quickly adjusted to the light level. I do not like using torches or spotlights to watch wildlife at night. All one can then see is what is in the beam, we are blind to anything beyond the white. With two weeks of moon larger than a quarter, there are plenty of nights for good watching. I used the flash here to see what prey the adults were bringing in. With flash I can grab an image and identify the prey species later at the desk. And there is no need to use full flash either. I do not like images of nocturnal animals like up like Christmas trees in bright artificial-coloured flash. I like to photograph what I see - softly flying birds in soft light, silent as ghosts (apart from the chicks' spooky low growling).

Mum with two of the kids under a full moon

Tawny Frogmouth Trio

A Tawny Frogmouth flies onto her nest with a large spider to feed to her chicks

During my study of Tawny Frogmouths Podargus strigoides I have collected 342 nest records and most of those have been by pairs of birds. However, four have been by trios of birds, one of which from this year is shown here.

The two females have roosted together all breeding season, about fifty metres from the male on the nest

Two females have been together with a male since the beginning of the nesting season and they are readily identifiable from one another as one bird is grey and the other has much more rufous in her plumage, especially on her wing coverts and scapulars. I didn't know whether these extra birds in breeding groups take part in rearing the young, so I watched this group over a few nights to see if all three birds fed the chicks. Under a quarter moon, there was enough light to see the three birds fly in and feed the chicks and I recorded the incidents with flash photography for confirmation.

The male sits on the nest all day - note his bold markings on a pale grey background plumage colour 

The male was easy to identify as his markings are very bold on his overall light grey body plumage, especially on his breast. At night, under flash, these contrasting markings are even more boldly emphasised. He, like all other male frogmouths which I have recorded at nests, regularly took his turn at feeding the chicks.

The male is readily identifiable by his large size, strongly contrasting plumage and well-speckled breast

When the birds landed with their backs to the camera, they could be identified by the colour of their wing coverts and tail feather patterns. The females were noticeably smaller than the male and they could be seen to bring in prey and feed the chicks which gave soft begging calls as they took the food from the adults.

The red female feeds the chicks 

Here the red female can be seen feeding the chicks, then nine seconds later, the grey female flew in and the red bird took off to the right over the camera. The incoming female can be seen carrying a beetle in her bill.

The red female leaves the nest as the grey female flies in with food

One feature that could only be detected with the photography was the difference in wing feather moult between the two females. The red bird had complete, fully grown primaries, secondaries and tail feathers. The grey bird was moulting three inner primary feathers, with moult scores of 4, 3 and 3, all the rest were complete, more likely old rather than newly-grown as most birds moult post-breeding.

The grey female leaves the nest, showing that her inner primary wing feathers are in moult

These differences in the birds moult were best captured in shots of the birds leaving the nest when they had opened their wings fully on take-off, compared with when they closed their wings on landing.

The red female leaves the nest, showing all primary, secondary wing feathers are fully grown and her tail is complete 

Other data which I collect when watching these birds at night are the frequency at which the chicks are fed, over the whole night, by the different sexes of adult, under various weather conditions etc. It will be a while before I collect all that data though.

Another shot of the red female leaving the nest and showing her complete wing feathering

Lunar eclipse

What I like about a red moon is how, when viewed through binoculars, we can see it in a three dimensional effect with the stars beyond - much better than that through a telescope, or when the moon is too bright.

Last night, October 8th, at about 2150 hrs, I photographed the Lunar Eclipse as the blood red colour began to wash off the lunar surface. A night with a  full moon is usually a good time to watch Tawny Frogmouths, or any other nocturnally active animal as they can be seen without artificial light or night-vision equipment. Not under a red moon though, it was too dark. I don't normally take flash photographs of frogmouths, but I took this one to see if there was a chick beneath the adult bird sitting on the nest. I just couldn't see for sure. However, the camera didn't help. Yet there was one, as I saw a little later when the bird's mate, the female, came in with some prey and passed it to a tiny chick hidden by the nest rim. The adults red eye-shine reminded me of the red moon.

Double-pink

Double-pink sitting quietly in her roost 

Double-pink, a female Tawny Frogmouth that has been breeding within my frogmouth study area in Canberra now for three years. She was released by the RSPCA after a road accident and subsequent treatment, and it was they who put the two pink colour-rings/bands on her legs. These are obviously not having any effect on her as she and her partner reared two chicks two years ago, then another last year.

Now she is back in the same home range and the pair again have eggs in their nest.

One of her pink rings - she has one on each leg

The eggs were probably laid last week, and incubation takes about a month. So it might be a while before I post any updates on their progress, but keep in touch. Last time I posted on their breeding there were lots of viewers.

Her partner sits on the nest all day

New paper on Tawny Frogmouth nesting behaviour

The cover of the current edition of Australian Journal of Zoology is illustrated with one of my photographs,
showing a Tawny Frogmouth in a typical nest site

The current issue of the Australian Journal of Zoology carries a paper by me and Duncan Rae on the nesting behaviour of Tawny Frogmouths in the Canberra area. This presents and discusses a set of results based on 253 nest records over several years. The brief online abstract and citation are reproduced below, but the full abstract and paper can be obtained by clicking on this link: Orientation of tawny frogmouth (Podargus strigoides) nests and their position on branches optimises thermoregulation and cryptic concealment

Tawny frogmouths (Podargus strigoides) in south-east Australia place their nests on open coarse-barked branches orientated to the north-east. This would fit their cryptic plumage and behaviour, expose the nesting birds to sunshine, shelter them from prevailing wind, give good visibility for detecting predators and clear space for rapid escape.

Rae, Stuart and Rae, Duncan (2014). Orientation of tawny frogmouth (Podargus strigoides) nests and their position on branches optimises thermoregulation and cryptic concealment. Australian Journal of Zoology 61, 469-474.

A Tawny Frogmouth sits over his two chicks

Frogmouths in the sun

A Tawny Frogmouth basks in sunshine

Ever wondered what tawny Frogmouths do when we aren't watching, and they don't adopt their broken branch pose? Following on from the previous post, I thought I should add some images of how frogmouths hold themselves when not in alarm, as usually seen by humans.

Typically, they sit on the sunny side of trees where they can bask in the sun. Frogmouths can go into torpor during the day when they are not active and exposure to maximum sunshine, especially in winter, helps them thermoregulate. When sitting in the sun, they hold their breast up towards and face onto the sun. And they tilt their head back and fluff out their feathers, which are held tight against the body when in branch-pose.

Well shaded eyes

Frogmouths don't hunt by day and they hold their eyes closed when their head is angled towards the sun or when approached. But at other times when they are looking around, generally watching, their eyes are well shielded from the sunshine by thickly feathered eyebrows. As their eyes are likely better tuned to night vision, this probably aids their daylight vision, by shading them from bright direct light.

Quite frequently, they will bend their head right back and over a shoulder, spreading the feathers on their neck and breast wide open. This seems to be to allow maximum sunlight or heat reach their skin. In the photograph below, the bird has tipped her head to her left and her bill tip and nasal bristles can only just be seen protruding from the fluffed up plumage.

Maximised sun basking

A close call

A Tawny Frogmouth sits on its nest, hiding from me, not the Crimson Rosella 

Tawny Frogmouths are well known to adopt a branch-pose to hide from potential predators, as they usually do when approached by a human. So it was illuminating to watch what they do when an animal predator approaches them.

Yesterday, this bird was unconcerned when a Crimson Rosella landed on its nest branch, but quickly slipped into the angled pose as I drew nearer. Then while I was looking for the female roosting a few trees away, she began to call in a low oom oom. This is most unusual as they do not normally call at all when approached. And then she started to fidget, leaving her branch-pose and shifting along her perch. Her eyes were wide open, they keep them closed when approached as part of their concealment, and I was wondering what was up, when I heard a cawing back beside the nest.

The female frogmouth in alarm

Two Australian Ravens were hopping about in the tree next to the nest, staring at the bird on the nest, which was back in a branch-pose. She had obviously seen them approach the nest well before me and was anxous as to what to do. For frogmouths are loath to fly in daylight, yet she seemed to want to help chase off the ravens from her nest.

Two Australian Ravens investigated the frogmouth on the nest

The male by then had his hackles partly raised, and his bill was slightly open. I suspect that he might have been giving a low hissing call as the ravens drew closer. I am sure they had identified him as a bird on a nest, but perhaps his partial threat display was enough to make them unsure. We can't tell, but they flew away to join the rest of the roving flock which they were part of. Hopefully not to return. 

Fortunately they flew away

Fledging Frogmouths

A Tawny Frogmouth fledgling basks in the sun

The first Tawny Frogmouths fledged at the weekend, with one chick leaving the nest a day before its siblings, which left the next day. So, a brood of three from the earliest nesting attempt of the year, by the same pair which laid earliest last year and reared three chicks then too.

Meanwhile its dad continues to brood two chicks in the nest on the next branch

The female was sitting low in a branch and was most un-noticeable. Then once they had all fledged the whole family moved into an adjacent tree. They will continue to move around their home range from now on, roosting in a different spot most days.

 

And mum watches on in-obtrusively

Brood of three

The male Tawny Frogmouth covers the chicks during the day

The pair of  Tawny Frogmouths which nested earliest in my study area in Canberra now have three well-grown chicks, about three weeks old.

I recorded their activity remotely last night on a Bushnell trap-camera set on an adjacent branch, and they seem to be bringing in moths to the chicks. Certainly small wingless tubular bodies and one very small frog. There are lots of Bogong moths Agrostis infusa in Canberra at the moment as they migrate from their breeding grounds to the hills south of the area. So there is plenty food for all five birds.

Click on this link if you would like to see footage of the three chicks jiggling for space on the nest.

One Frogmouth less

The scattered feathers of a plucked Tawny Frogmouth

Today, while checking what used to be a Tawny Frogmouth territory, looking for this year's nest, I couldn't find anything. No nest, no birds. Then I found out why. There was a cluster of plucked feathers, from a Tawny Frogmouth, lying not far from the previous year's nest site. As the quills were all pulled out rather than snapped off, this is indicative of the bird having been killed and eaten by a raptor, most likely a Brown Goshawk as they nest a few hundred metres from the site. A mammal would have bitten off the feathers leaving cut shafts.

The kill was not recent, and as I could not find even a partially-built nest, I reckoned that the bird had been killed before the pair had began nesting. I still could not find the other bird of the pair, but it might have shifted a few hundred metres, and perhaps found a new mate and still be breeding. That will take another visit to check.

The complete shafts indicate that the feathers were plucked by a raptor.

Tawny Frogmouths at night

The moon and Venus above the female frogmouth

I was out watching the frogmouths last night with Steph and Matt. There were a pair which appeared with fledged chicks last year from an unknown nest site, so we staked out the area at dusk. The female was calling from her daytime roost perch for ten-fifteen minutes as the light faded. Then as it became truly dark she shifted to another perch and continued to call her rapid repeating 'ooom-ooom'. The call is distinctive, but so soft, we wondered how far away her mate was. The call only carried to our ears for about fifty metres. Do they do so to avoid attracting attention from their main night-time predator, the Powerful Owl? Then the male swooped in silently from the shadows and landed right next to her. She twitched her tail, he jumped onto her back and they mated for a minute or so. He then went off and hunted, catching an insect from some foliage up in a tree. She flew over to their nest site and continued to call. 

So, we accomplished our quest to find the nest site and all this happened in about half an hour immediately at the onset of true darkness. There is so much to see in the dark.

The distinctive silhouette of a Tawny Frogmouth - a broad, bushy head and a tapering tail