Minuscule Hummingbird-Sized Archaic Birds Existed During the Cretaceous

UPDATE (added 13th March 2020): since I published the article below, two relevant matters have come to attention, both of which have implications for the fossil discussed in the article.

Article at left from New Scientist; article at right from New York Times.

The first is that the extraction of amber from the locations concerned is linked with significant humanitarian issues. These make the continued publication and promotion of Burmese amber fossils look unethical; I was only dimly aware of these when writing the article and now regret my (minor) role in the promotion of this discovery (I did plan to delete the article but, on advice, was encouraged to keep it, but add the disclaimer you’re reading now). You can read about the humanitarian issues here, here and here.

Secondly, a number of experts whose opinions I respect have expressed doubts about the claimed theropod status of the fossil discussed below and have argued that it is more likely a non-dinosaurian reptile, perhaps a drepanosaur or lepidosaur (and maybe even a lizard).

A few artists have already produced speculative life reconstructions of Oculudentavis as a lepidosaur or similar reptile. It would have to be a big-brained, shallow-snouted, big-eyed one. Image: (c) Mette Aumala, used with permission.

I did, of course, consider this sort of thing while writing the article but dismissed my doubts because I assumed that - as a Nature paper - the specimen’s identity was thoroughly checked and re-checked by relevant experts before and during the review process, and that any such doubts had been allayed. At the time of writing, this proposed non-dinosaurian status looks likely and a team of Chinese authors, led by Wang Wei, have just released an article arguing for non-dinosaurian status. I don’t know what’s going to happen next, but let’s see. The original, unmodified article follows below the line…

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If you’ve been paying attention to 21st century palaeontological discoveries you’ll know that our understanding of Cretaceous vertebrate diversity has been much enhanced in recent years by the discovery of animals preserved within amber.

A number of really interesting vertebrate fossils in amber have been published in recent years. Among them are the two partial enantiornithine bird wings shown at left (both from Xing et al. 2016a), and the tiny anguimorph lizard Barlochersaurus winhtini (from Daza et al. 2018). Images: Xing et al. (2016), CC BY 4.0, Daza et al. (2018).

These include lizards and snakes (Daza et al. 2016, 2018), a segment of dinosaur tail originally identified as that of a non-bird theropod (Xing et al. 2016b), and various small birds (e.g., Xing et al. 2016a, 2017, 2018, 2019), all of which belong to the archaic, globally distributed group known as the enantiornithines or opposite birds. Today sees the latest of such discoveries, and it’s the most remarkable announced so far. It is – in fact – among the most remarkable of Mesozoic fossils ever announced, and I say this because of the implications it has for our understanding of Mesozoic vertebrate diversity.

Life reconstruction of Oculudentavis khaungraae Xing et al., 2020, depicting it as a tree-dwelling avialan theropod with partly colourful plumage. Image: (c) Gabriel Ugueto, used with permission.

The fossil in question, described in the pages of Nature by Lida Xing, Jingmai O’Connor and colleagues, is the complete, anatomically pristine but minuscule skull of a maniraptoran theropod – specifically, an archaic bird – named Oculudentavis khaungraae (Xing et al. 2020). The skull is preserved in a small amber block (31.5 x 19.5 x 8.5 mm) dating to the Cenomanian age of the Late Cretaceous (making it about 99 million years old). Like virtually all recently described amber vertebrates, it’s from Myanmar (Xing et al. 2020).

One of several images of the tiny Oculudentavis skull provided by Xing et al. (2020), this one (from their Extended Data) showing the specimen in left lateral view. The scale bar is 2 mm. Image: Xing et al. (2020).

When I say that this fossil is ‘minuscule’, I’m not kidding: the entire skull – the whole skull – is 14 mm long (1.4 cm; not a typo)*. This means that – at a very rough guess – the whole animal was around 90 mm (9 cm) long, an estimate I arrived it by producing a very schematic skeleton which equips the animal with a long tail. Xing et al. (2020) very rightly compare Oculudentavis with small hummingbirds: if it had a long bony tail (which it should have, given its inferred phylogenetic position; read on), it would have been longer than the tiny Mellisuga hummingbirds, the total lengths of which are around 50-60 mm, but not by much. It was unbelievably tiny.

* I’m frustrated by the fact that the authors don’t – so far as I can tell – provide the length of the entire skull anywhere in the paper, nor is there a table of measurements or an effort to estimate the animal’s complete size. Which is weird, because surely this is the most interesting thing about it.

A very rough, semi-schematic skeletal reconstruction of Oculudentavis which I produced in order to gain a rough idea of possible size. As you can see, it would have been tiny. The overall form of the skeleton is based on that of jeholornithiform birds; read on. Image: Darren Naish.

The skull of Oculudentavis has a typical ‘birdy’ look. It has a longish, shallow rostrum, large eye sockets, a lot of bone fusion (no, it isn’t a baby) and a rounded cranium where the section posterior to the eyes is short and compact (Xing et al. 2020). The nostrils are retracted, there’s no trace of an antorbital fenestra, the bony bars beneath the eye sockets bow outwards, and there’s a complete bony bar separating each eye socket from the openings at the back of the skull (Xing et al. 2020).

Digital scan of the skull of Oculudentavis in right lateral view (from the Extended Data of Xing et al. 2020). Note the overall toothiness. The dotted lines here show where slices were recorded during the scanning process. Image: Xing et al. (2020).

It’s a toothy little beast, with an atypically high number of conical (or near-conical) teeth lining its jaws all the way back to beneath the eye socket. This is unusual, since the toothrow in toothed birds and bird-like theropods in general normally stops well anterior to the eye. Another unusual feature is that the teeth aren’t located in sockets but are either fused to the jaw bones (the acrodont condition) or located within grooves that extend along the length of the jaws (the pleurodont condition) (Xing et al. 2020). The teeth look prominent, such that it’s hard to understand how they could be sheathed by lip tissue, nor is any such tissue preserved. Remember that beak tissue doesn’t occur in the same part of the jaws as teeth do, so Oculudentavis wouldn’t have had a true horny covering on its jaws. I assume that it had ‘lip’ tissue sheathing its teeth (except perhaps for the tips of the longest ones), as do other terrestrial tetrapods.

Speculative life reconstruction of Oculudentavis, its feathering and other details inspired by Jeholornis and other archaic members of Avialae. I’ve depicted it on the forest floor but am not necessarily saying that this is where it spent all of its time. Image: Darren Naish.

The eyes are directed laterally and the authors note that Oculudentavis likely didn’t have binocular vision (Xing et al. 2020). The sclerotic rings are huge and fill up most of the eye sockets. Xing et al. (2020) use the relative size of the eyes and their sclerotic rings to make inferences about the activity patterns and visual abilities of this animal: they think that Oculudentavis was likely day-active, had relatively small pupils, and perhaps had “unusual visual capabilities”.

The fossil doesn’t just consist of the animal’s bones alone, because synchrotron scanning reveals the presence of a brain (which is about as wide as it is long). Meanwhile, the bony palate preserves traces of its original tissue covering. This is decorated with numerous papillae, the first time such structures have been reported in a fossil theropod (Xing et al. 2020). The authors also refer to a tongue (!!) but it isn’t possible to make this out in the figures they provide, nor do they label it.

Combined, what do these features tell us about the lifestyle and ecology of Oculudentavis? The well-fused skull, prominent teeth and large eyes suggest that this was a predator, presumably of small arthropods. The soft papillae on the palate are of the wrong sort for fish-eating (Xing et al. 2020). Its tiny size and forest habitat imply that it was arboreal or scansorial – as suggested by Gabriel’s artwork above – but the animals that surround it in the cladogram are mostly terrestrial, so the possibility that it foraged in leaf litter or took regular trips to the forest floor are also conceivable, perhaps. Could it have been a predator of worms, molluscs or even tiny vertebrates, like a dinosaurian shrew?

Oculudentavis would have looked noticeably small relative to other Mesozoic birds, though not absurdly so. It’s compared here with Archaeopteryx (at upper left) and an assortment of others, most of which are enantiornithines. These illustrations are for my in-prep giant textbook project. Image: Darren Naish.

What sort of bird is Oculudentavis? For starters, it’s the presence of fused premaxillary and braincase bones, the position and size of the nostril, eye, postorbital region and domed cranium which strongly indicate that Oculudentavis is a member of Avialae, the bird lineage within Maniraptora (though note that the authors prefer the term Aves for said lineage). They included it within a phylogenetic analysis and found it to be one step more crown-ward (meaning, one node on the cladogram closer to living birds) than is Archaeopteryx, which is surprising because it makes Oculudentavis one of the most archaic members of the bird lineage (Xing et al. 2020). This could mean that birds underwent acute miniaturisation almost as soon as they evolved. Several authors – myself and colleagues included (Lee et al. 2016) – have argued beforehand that theropods on the line to birds underwent a gradual and pervasive decrease in size, but we didn’t (and couldn’t) predict that a size decrease of this sort occurred so early in bird history.

Theropods display a continuous, pervasive decrease in size when we look at the inferred size of ancestral species at successive nodes across the lineage leading to birds. From left to right, this illustration by Davide Bonnadonna shows the ancestral neotheropod (~220 Million years old), the ancestral tetanuran (~200 myo), the ancestral coelurosaur (~175 myo), the ancestral paravian (~165 myo), and Archaeopteryx (150 myo). Image: Davide Bonnadonna.

A World of Tiny Cretaceous Theropods? A key thing here is that we only know about this animal because of its preservation in amber: the rest of the fossil record mostly – the authors suggest – robs us of tiny vertebrates such as this. Could there actually have been many hummingbird-sized miniature theropods of this sort?

Xing et al. (2020) don’t provide a size estimate for Oculudentavis, but they do provide these silhouettes, which show Oculudentavis to scale with a hummingbird and chicken (and part of an ostrich is just visible at far right). Image: Xing et al. (2020).

Here’s where Xing et al.’s (2020) cladogram become especially interesting. The position they propose for Oculudentavis requires that its lineage originated about 150 million years ago, and yet Oculudentavis itself is about 99 million years old. Its lineage, therefore, is at least 50 million years long, in which case there could have been many of these tiny avialan dinosaurs (here, I have to resist the urge to talk about the hypothetical tree-climbing small dinosaurs of Dougal Dixon and George Olshevsky). I emphasise that this speculation assumes that the phylogenetic position Xing et al. (2020) infer is correct; it may not be. Indeed 10% of their trees found Oculudentavis in a different position: within enantiornithines, a possibility which seems ‘more right’ given the identity of other Burmese amber birds. With just a skull to go on, we obviously need more material before we can be especially confident on its phylogenetic position. And on that point, I won’t be surprised if it turns out that Oculudentavis does end up occupying a different position within maniraptoran theropods from the one which Xing et al. (2020) prefer. But none of this affects its minuscule nature, and that’s the real killer point here.

Part of a time-calibrated theropod tree (from Wang & Zhou 2017). According to Xing et al. (2020), Oculudentavis occupies a position more root-ward than Jeholornithiformes, but more crown-ward than Archaeopteryx. If correct, this means that its lineage originated during the latest part of the Jurassic. Image: Wang & Zhou (2017).

What About Other Fossil Vertebrates? If tiny, tiny Cretaceous theropods have remained unknown to us until now, what about other terrestrial vertebrates? I’d always assumed that the truly tiny frogs, lizards and other vertebrates of the modern world – those less than a few centimetres long – were recently evolved novelties of the Cenozoic. But maybe this is completely wrong. Maybe animals of this sort were present in the Mesozoic too, and maybe we’ve missed them due to a size filter which can only be filled by fossils discovered in amber?

The modern world is inhabited by truly tiny lizards and frogs, like this c 3cm SVL Brookesia chameleon and c 1cm Stumpffia frog. Were similarly tiny tetrapods also around in the Cretaceous? Images: (c) Mark D. Scherz, used with permission.

Time will tell. This is really exciting stuff.  

If you enjoyed this article and would like to see me do more, please consider supporting this blog (for as little as $1 per month) at patreon. The more support I receive, the more financially viable this project becomes and the more time and effort I can spend on it. Thank you :)

For previous TetZoo articles relevant to this one, see…

• Bird behaviour, the ‘deep time’ perspective, January 2014

• 50 million years of incredible shrinking theropod dinosaurs, July 2014

• The Romanian Dinosaur Balaur Seems to Be a Flightless Bird, June 2015

• The Most Amazing TetZoo-Themed Discoveries of 2018, December 2018

• A Multi-Species Nesting Assemblage in the Late Cretaceous of Europe, February 2019

Refs - -

Daza, J. D., Bauer, A. M., Stanley, E. L., Bolet, A., Dickson, B. & Losos, J. B. 2018. An enigmatic miniaturized and attenuate whole lizard from the mid-Cretaceous amber of Myanmar. Breviora 563, 1-18.

Daza, J. D., Stanley, E. L., Wagner, P., Bauer, A. M. & Grimaldi, D. A. 2016. Mid-Cretaceous amber fossils illuminate the past diversity of tropical lizards. Science Advances 2 (3), e1501080.

Lee, M. S. Y., Cau, A., Naish, D. & Dyke, G. J. 2014. Sustained miniaturization and anatomical innovation in the dinosaurian ancestors of birds. Science 345, 562-565.

Wang, M. & Zhou, Z. 2017. The evolution of birds with implications from new fossil evidences. In Maina, J. N. (ed) The Biology of the Avian Respiratory System. Springer International Publishing, pp. 1-26.

Xing, L., McKellar, R. C., O’Connor, J. K., Bai, M., Tseng, K. & Chiappe, L. M. 2019. A fully feathered enantiornithine foot and wing fragment preserved in mid-Cretaceous Burmese amber. Scientific Reports 9, 927.

Xing, L., McKellar, R. C., Wang, M., Bai, M., O’Connor, J. K., Benton, M. J., Zhang, J., Wang, Y., Tseng, K., Lockley, M. G., Li, G., Zhang, Z. & Xu, X. 2016a. Mummified precocial bird wings in mid-Cretaceous Burmese amber. Nature Communications 7, 12089.

Xing, L., McKellar, R. C., Xu, X., Li, G., Bai, M., Scott Persons IV, W., Miyashita, T., Benton, M. J., Zhang. J., Wolfe, A. P., Yi, Q., Tseng, K., Ran, H. & Currie, P. J. 2016b. A feathered dinosaur tail with primitive plumage trapped in mid-Cretaceous amber. Current Biology 26, 3352-3360.

Xing, L., O’Connor, J. K., McKellar, R. C., Chiappe, L. M., Bai, M., Tseng, K., Zhang, J., Yang, H., Fang, J. & Li, G. 2018. A flattened enantiornithine in mid-Cretaceous Burmese amber: morphology and preservation. Science Bulletin 63, 235-243.

Xing, L., O’Connor, J. K., McKellar, R. C., Chiappe, L. M., Tseng, K., Li, G. & Bai, M. 2017. A mid-Cretaceous enantiornithine (Aves) hatchling preserved in Burmese amber with unusual plumage. Gondwana Research 49, 264-277.

Xing, L., O’Connor, J. K., Schmitz, L., Chiappe, L. M. McKellar, R. C., Yi, Q. & Li, G. 2020. Hummingbird-sized dinosaur from the Cretaceous period of Myanmar. Nature 579, 245-249.

Suburban Birdwatching in Queensland, Australia

I recently spent time in Australia, and specifically in Brisbane, Queensland (this was for the 79th Society of Vertebrate Paleontology annual meeting), and, while there, I got to see a pretty good selection of birds. I photographed as many as I could, and in this article I’m going to talk about them. All the birds I’m going to discuss here were encountered in urban and suburban settings in close proximity to people, and none are especially exotic or obscure. But they were entirely novel to me, and I was hugely excited to encounter them in the wild. I hope you’ll enjoy reading about them.

Caption: Dusky moorhen, Australian white ibis and Little black cormorant captured in the same one shot (at left). At right: a wonderful Torresian crow. Images: Darren Naish.

One more bit of preamble: if I had the time and foresight, I could have organised a special birdwatching tour, in which case I could have been taken to various specific locations at which I might have seen a rather more impressive list of Australian birds not ordinarily encountered by mere chance. But… I didn’t. I wish I had.

Caption: if you’re truly interested in animals, you’re interested in invasives, aliens and introductions, and there’s no shame in paying attention to them or studying them. So go ahead and photograph that feral pigeon. Image: Darren Naish.

My very first Australian bird sighting was of Welcome swallows Hirundo neoxena, seen flying around the outside windows of Perth Airport. I was to see this species on several subsequent occasions (it occurs across virtually the whole of Australia except for some north-central sections), but no photos, sorry. My second species: the feral Rock dove or Rock pigeon Columba livia! I don’t care what anyone says: I always take time to look at feral pigeons, and one thing you notice is that populations differ from place to place, mostly because they descend from different founding populations of escapees or released birds. Brisbane pigeons were especially dark relative to the majority of familiar urban pigeons in Europe, and on the large size too. Brisbane: make of that what you will.

Caption: my first bin chicken. This individual spent time probing into the gap between the pavement and a retaining wall, searching for arthropods. Image: Darren Naish.

My second Aussie bird was something far more exotic (to me): an ibis, and specifically an Australian white ibis Threskiornis molucca. This species was included within T. aethiopica – the species currently referred to as the African sacred ibis – until the mid-2000s, and some authors still regard the two as conspecific. The Black-headed ibis, Black-necked ibis, Oriental white ibis or Indian white ibis T. melanocephalus is part of this complex too (all three are regarded as part of the same superspecies). Apparently, there are Australian people who still refer to T. molucca as the Sacred ibis but --- as any Australian will tell you within 0.5 seconds of you expressing interest in this bird, it’s not ‘the Australian white ibis’ to the vast majority of urban Australians but ‘the bin chicken’: an animal that people associate with rubbish, waste food and urban filth in general. I get the impression that Aussies love to hate the ibis the same way people also dislike urban gulls and pigeons. Hey idiots... the shitty trash the bird is eating is, like, YOUR trash and YOU put it there.

Caption: Australian white ibis out and about in town. Image: Darren Naish.

Australian white ibises seem to be both abundant in Brisbane and extremely bold. Large groups are present in the parks throughout the city, groups can be seen nesting at the tops of palms and other trees in the parks, and individual birds can be seen walking around in crowded pedestrianised areas and even right into cafes and restaurants… though they aren’t exactly welcome in such places.

Caption: large numbers of ibises are readily visible in parks and other green places in Brisbane. The birds stand or sit on the grass and rest in trees. The first individual I saw (the one probing in the paved area, shown above) was initially sat on the grass, chest against the ground. Image: Darren Naish.

Caption: aaaand… even more ibises. Image: Darren Naish.

Go near the water most places in the world, and you’ll very likely see members of the duck, goose and swan family Anatidae, and such it is in Australia. I saw three species, all new to me, all in close proximity to the ponds in Brisbane’s Botanical Gardens. We’ll start with the Australian wood duck, Maned duck or Maned goose Chenonetta jubata, a heavily terrestrial, pan-Australian, cavity-nesting duck that might be a member of the shelduck clade Tadorninae. The birds I saw were asleep (or pretending to be asleep) and thus standing and sitting still with their eyes closed.

Caption: at left, two Australian wood ducks. resting or sleeping. At right: a Hardhead heads across the water towards me. Presumably, it (and its partner) was used to being fed by people. Image: Darren Naish.

Pacific black ducks Anas superciliosa – PBDs in birding vernacular – were also seen; this is an especially handsomely marked member of the mallard complex, the different forms of which are quite variable across its southwest Pacific/Australasia range. Another first for me was Hardhead or White-eyed duck Aythya australis, a Pacific/Australasian member of the scaup and pochard lineage (Aythyini).

Caption: Pacific black duck. Of the three recognised subspecies, the Australian one is A. superciliosa rogersi. This subspecies also occurs in Indonesis and New Guinea. Image: Darren Naish.

My biggest surprise at the ponds, however, was an Australian darter or anhinga Anhinga novaehollandiae (here I’m following recent studies in recognising this as a distinct species from African and Asian anhingas), which I watched for some time as it foraged and hunted close to the water’s edge. On occasion, it would disappear entirely from view before stretching its long, slender neck out of water while swallowing a fish. And on other occasions, its long tail could be seen part emerging above the surface while the bird was part swimming, part floating, just beneath the surface. I’ve never seen a live anhinga before. This one was smaller than I expected.

Caption: an anhinga surfaces and swallows what I presume is a fish. Image: Darren Naish.

Caption: more swimming anhinga action. Image: Darren Naish.

Caption: Little pied cormorant, foraging in a shallow pool with abundant algae and other aquatic plants. Its appearances at the surface were really brief compared to the other cormorants I’ve watched, and this is the only photo that clearly shows its head and bill. Image: Darren Naish.

Two cormorant species were also present at the ponds: Little black cormorant Phalacrocorax sulcirostris (see photo at the top of the article) and Little pied cormorant P. melanoleucos (or Microcarbo melanoleucos, if you follow Siegel-Causey’s (1988) taxonomy). The one individual of the latter I saw was diving for food in a heavily vegetated pool. A group of three Dusky moorhens Gallinula tenebrosa were paying close attention to its activities, and would circle and peck at the surface every time the cormorant would dive. I assume that they were interested in bits of vegetation and small animals brought to the surface by the cormorant’s activities. Indeed, numerous small fish and tadpoles were present in the pools. The tadpoles looked like those of a toad and I presume they were Cane toad Rhinella marina larvae, indeed I know that Cane toads were present since I found two dead ones in the park grounds.

Caption: Dusky moorhens search for food in an area where the water is being disturbed by a swimming Little pied cormorant. Image: Darren Naish.

Dusky moorhens were frequently encountered and easily approached. As suggested by the name, they looked darker than the Eurasian moorhens G. chloropus I know well, and they appeared larger and chunkier too. I watched them foraging on lawns, and a bit of squabbling, chasing, fighting and mating was seen as well.

Caption: Silver gulls look similar to Northern Hemisphere species like the Black-headed gull Chroicocephalus ridibundus, and there’s a reason for that. Image: Darren Naish.

Finally on birds associated with watery places, I also visited an artificial beach close to the Brisbane River where there were numerous Silver gulls Chroicocephalus novaehollandiae. This is Australia’s most widespread gull and occurs around the country’s entire coast as well as in many inland locations. The Silver gull is surrounded in phylogeny by species that have grey, black or brown heads (Chu 1998) and is thus generally agreed to be part of the Chroicocephalus group (and is thus not part of Larus in the new, restrictive sense). At least a few other Chroicocephalus species are like the Silver gull in being white-headed too, so it might be that a transition from a dark head back to a white one happened a few times in this group. The Silver gull is a mid-sized, slender-billed gull.

Caption: Masked lapwing, or Black-shouldered lapwing if you’re so inclined. Note that the carpometacarpal spurs aren’t readily visible here. Image: Darren Naish.

I also saw a single plover, specifically a Masked lapwing Vanellus miles… and, more specifically, the black-shoulder form V. m. novaehollandiae (jeez, colonial Europeans: couldn’t you be a bit more creative with the scientific names?) sometimes recognised as the distinct species V. novaehollandiae, the Black-shouldered lapwing. This bird was wandering around on a lawn close to a restaurant. Lapwings – technically called vanellines – are conventionally included within Charadriidae, the plover family. Lapwings are interesting in that they possess large spurs on the carpometacarpus, which are typically (but not always) visible when the wings are closed. These are used in defence against predators (like cats, dogs and corvids) and also in intraspecific fights. There’s an apparent common folk belief that the spur is venomous! Here’s your regular reminder that TetZoo ver 3 includes two fairly comprehensive articles on the spurs, claws and clubs present on the wings of birds (part 1 here, part 2 here; I’ve linked to wayback machine versions as they include the illustrations).

Caption: a Laughing kookaburra in the wild, perched and vigilant. Image: Darren Naish.

I was surprised (hey, I’m from Europe) to see a Laughing kookaburra Dacelo novaeguineae in an urban park, sat on top of a streetlight and also in flight in the same park. I gather than kookaburras are pretty typical park and garden birds in parts of Australia, well known for their habit of grabbing food from tables and barbeques and such. Most of you will know that kookaburras are especially big kingfishers, closely related to Halcyon kingfishers and kin, and that the bulk of kingfisher diversity exists in the islands and coastal regions of Australasia. Kingfishers have conventionally all been included within the same one family (Alcedinidae), and this is still a popular view. However, the idea that lineages within the group are ‘distinct enough’ that several kingfisher families should be recognised is also popular, in which case kookaburras and their close kin belong within Halcyonidae (previously known, incorrectly, as Dacelonidae; Sibley & Ahlquist 1990). Miners (more on them in a minute) are not fans of kookaburras and a few individuals took time to mob the individual sat on top of the streetlight.

Caption: a Noisy miner (at left) arrives to harass a Laughing kookaburra. Image: Darren Naish.

I was also pleased to see Rainbow lorikeets Trichoglossus moluccanus at a few places, though none of my photos are at all good. Lorikeets mostly eat pollen and nectar and their specialised brush-like tongues explain their generic name – Trichoglossus means ‘hair tongue’. I actually saw parrots of a few other species as well, but they were right at the top of really tall trees and mostly seen in silhouette, so I never saw any of the detail that might allow them to be identified.

Caption: Rainbow lorikeet at the top of a palm tree. The green collar confirms the identification, since similar lorikeet species (like the Red-collared lorikeet T. rubritorquis) lack this feature. Image: Darren Naish.

As everyone who knows anything about birds knows, the majority of living bird species (over 60% of them) are passerines (or perching birds), and most of the Australian species I saw were members of this enormous group. I didn’t see any feral European starlings or sparrows, or indeed any introduced European species at all, and nor did I see any small endemic Australian endemics, like fairywrens, pardalotes or sunbirds.

Caption: a Noisy miner, eating parts of a Mexican burrito on a restaurant table. Image: Darren Naish.

We’ll start with Noisy miners Manorina melanocephala. These are mostly grey, thrush-sized passerines – happy to take to the ground as well as forage in trees and shrubs – that have a robust bill and naked yellow patch of skin behind the eye. They’re bold and look to have made the full transition to life in urban settings. I saw them jump around on tables and eat food from plates just moments after people had left, and I also saw them waiting for dropped food scraps right next to a person sat on the grass. In one case, a man eating his lunch while sat in the park was literally slapping the birds out of the way.

Caption: Common or India mynas are one of the most important alien birds in Australia (‘important’ in economic and ecological terms). Note that this individual is afflicted by a problem most commonly associated with urban pigeons: mangled toes and missing toe segments (the hallux claw is missing on the left foot). Image: Darren Naish.

The fact that these birds are called ‘miners’ is a bit confusing, since this makes it sound as if they’re ‘mynas’ (also spelt ‘mynahs’); that is, members of the starling and myna family Sturnidae. But they’re not, they’re honeyeaters (Meliphagidae). There are, incidentally, proper mynas in Australia: namely, the introduced Common or Indian myna Acridotheres tristis from tropical southern Asia. I saw some of these as well (I also saw them while on the journey home, in Singapore). Back to honeyeaters: Australia is the land of honeyeaters, the country being home to about half of the c 190 extant species. For all that I only saw one other meliphagid species: the Blue-faced honeyeater Entomyzon cyanotis.

Caption: a Blue-faced honeyeater, photographed at distance while it was on the top of a building. The area of blue facial skin is variable in these birds; this individual seemed to have only a small amount of blue. The skin is green in juveniles. Image: Darren Naish.

Moving on, Australia is also home to a really exciting assortment of sometimes large, omnivorous and predatory, superficially crow-like passerines, namely butcherbirds, currawongs and Australian magpies. I bet most people assume that these are corvids, but they aren’t: they’re conventionally allied within the family Cracticidae but a close relationship with woodswallows and kin means that the best course of action might be to include them within Artamidae, the woodswallow family. These birds are part of Corvoidea – the large passerine clade that includes shrikes, vireos, birds-of-paradise and corvids proper – but they’re some distance away from corvids, instead belonging to Malaconotoidea (also written Malaconotidea), a group that includes African bushshrikes and vangas (Cracraft et al. 2004, Cracraft 2014, Selvatti et al. 2015).

Caption: a Grey butcherbird (at left) waits for food in a park; to the right are a group of Noisy miners. Image: Darren Naish.

I saw a single Grey butcherbird Cracticus torquatus, hanging out in a park in close proximity to a group of miners. It was part of the group mentioned above, seen waiting near a person eating their lunch.

Caption: a (slightly blurry) Pied currawong caught in the middle of a run, just prior to takeoff. Image: Darren Naish.

Caption: Pied currawong from below. There are supposed to be three currawong species, but there are so many local variants, intermediate grades and island endemics that the story is quite difficult to resolve. Images: Darren Naish.

Pied currawong Strepera graculina were seen in trees, on tall buildings and structures attached to buildings, and on the ground. A pair were actually nesting on metal support structures just outside the conference venue but their nest was so high up and far from the ground that they were constantly at the edge of my camera’s range. Anyway, some of my photos aren’t terrible. And I did see Australian magpies on several occasions, but it was always while I was in cars, away from the city, and I never had the chance to get a photo.

Caption: Torresian crow, what an excellent bird. Image: Darren Naish.

Finally, Australia is also home to corvids proper. Australian crows are weird. To a European eye, they don’t look quite right – as if they might not be crows proper (which they are) – and yet they all look about enough alike that they could conceivably be close relatives (which they are: Jønsson et al. 2012). I saw members of two species, the first being a beautifully glossy, iridescent  bird, about similar in size to typical Corvus crows like the Eurasian Carrion crow C. corone, and with a prominent pale iris. This was the Torresian crow C. orru, I assume named for the Torres Strait (the stretch of water between New Guinea and Australia). I saw this species both as a singleton and in a large group, often right in the middle of town.

Caption: more Torresian crows, both in a group, in a tree, and foraging on the ground in an urban area. Images: Darren Naish.

Caption: Torresian crows and flowers. I like the artiness of this photo. Image: Darren Naish.

The second crow species I saw was the larger, bulkier Australian raven C. coronoides. I saw a group of three of these, walking around together on a lawn. The large group of Torresian crows I saw appeared to be gathered together because they were unhappy about the proximity of these ravens, and they were peering in the ravens’ direction while noisily calling. I wanted to watch all of these corvids for longer, but my time was short and I had to run.

Caption: a pair of Australian ravens forage on a lawn, to the displeasure of nearby Torresian crows. Image: Darren Naish.

And that brings things to an end. There’s a vast amount of stuff that I never saw, much of it living in very close proximity to the part of Brisbane in which I was staying. But it wasn’t to be. One day I’ll visit Australia again, and I hope for better luck, more time, and more experience of the region’s remarkable wildlife.

For previous TetZoo articles on birds and birdwatching, see…

• To the Sahara in quest of dinosaurs (living and extinct), December 2008

• From Morocco, with larks, babblers, gazelles, owls and GIANT DINOSAUR BONES, December 2008

• Birding in Brazil: a view from suburban Rio de Janeiro, June 2013

• Birdwatching in Suburban China, May 2018

• Avocets in Flight and Phylogeny, October 2018

• Cocks-of-the-Rock, Extreme Cotingas, April 2019

If you enjoyed this article and want to see me do more, more often, please consider supporting me at patreon. The more funding I receive, the more time I’m able to devote to producing material for TetZoo and the more productive I can be on those long-overdue book projects. Thanks!

Refs - -

Chu, P. C. 1994. 1998. A phylogeny of the gulls (Aves: Larinae) inferred from osteological and integumentary characters. Cladistics 14, 1-43.

Cracraft, J. 2014. Avian higher-level relationships and classification: Passeriformes. In Dickinson, E.C. & Christidis, L. (eds) The Howard and Moore Complete Checklist of the Birds of the World (fourth edition), Volume 2: Passerines. Aves Press, Eastbourne, pp. xvii-xlv.

Cracraft, J., Barker, F. K., Braun, M., Harshman, J., Dyke, G. J., Feinstein, J., Stanley, S., Cibois, A., Schikler, P., Beresford, P., García-Moreno, J., Sorenson, M. D., Yuri, T. & Mindell, D. P. 2004. Phylogenetic relationships among modern birds (Neornithes): towards an avian tree of life. In Cracraft, J. and Donoghue, M. (eds) Assembling the Tree of Life. Oxford University Press (Oxford), pp. 468-489.

Jønsson, K. A., Fabre, P.-H. & Irestedt, M. 2012. Brains, tools, innovation and biogeography in crows and ravens. BMC Evolutionary Biology 12: 72.

Selvatti, A. P., Gonzaga, L. P. & Russo, C. A. de M. 2015. A Paleogene origin for crown passerines and the diversification of the Oscines in the New World. Molecular Phylogenetics and Evolution 88, 1-15.

Sibley, C. G. & Ahlquist, J. A. 1990. Phylogeny and Classification of Birds. New Haven: Yale University Press.

Siegel-Causey, D. 1988. Phylogeny of the Phalacrocoracidae. The Condor 90, 885-905.

Hacks Vs Wildlife: the Eternal Vilification of Gulls

Every summer, here in the UK, it’s the same. “CRAZED KILLER SEAGULL ATTACKED MY BABY”, “PSYCHO SEAGULL’S REIGN OF TERROR”, “EXPERT SAYS PUPPIES AND KIDS COULD BE NEXT”. It’s almost as if hack journalists, writing for shitty tabloids like The Mail, The Sun and The Star, have nothing smart to write about so fall back on scaremongering and the vilification of wildlife. Hack journalists are pretty good at this, stirring up waves of anti-gull feelings among a public that already dislikes any animal trying its damnedest to survive and persist in a land dominated by humans and their intolerance of wild places and other species (see #HacksVsWildlife on Twitter for a constant stream of this sort of thing).

Caption: it’s summertime in the UK, and this can only mean one thing….

Right now, the story of Gizmo the chihuahua – apparently snatched by a gull in Paignton, Devon – is doing the rounds. Gizmo is, or was, a very small dog, so the idea that he/she might have been grabbed by a big gull is not out of hand. I’m inclined to think that the event did happen, in which case Gizmo’s owners have my sympathy. Lesson for the future: don’t leave tiny dogs unguarded, outside, in an area where there are big gulls. As others have pointed out, big white-headed gulls like the Great black-backed Larus marinus can swallow prey the size of juvenile rabbits, and a big gull can likely fly while carrying an object about similar in size to a very small chihuahua (cf Young 1987).

Caption: alas, poor Gizmo. Screengrabs of headlines from some of the UK’s most noble gutter rags.

As cynical as it sounds though, this strikes me as an example of bad pet management more than a case of ‘out of control’ wildlife. I have a pet lizard and guinea-pig who are often taken outside in an area where there are gulls and corvids of several species, and I simply wouldn’t leave them alone and unguarded. What about those parts of the world where there are such things as coyotes, bobcats, eagles and other opportunistic predators? Who is to ‘blame’ when, say, a pet cat is taken by a coyote? Is it really because the coyote is in the ‘wrong’ place?

Caption: white-headed gulls (those gull species remaining in the genus Larus) are good-looking birds, in cases with wingspans that exceed 1.3 m. This is a Herring gull (photographed in Cornwall, England) with an unusually shaped head. Image: Darren Naish.

Are gulls big, formidable and potentially dangerous to small animals and even people? Yes, of course they are. They’re predatory and opportunistic, and often territorial and liable to be aggressive when guarding their nests and chicks. But the idea – promoted continually by hack journalists – that there’s some kind of GULL PLAGUE that we should rid ourselves of is just wrong, and bad.

Caption: Herring gulls consume leftovers at a restaurant in Tintagel, Cornwall. Image: Darren Naish.

Gulls Are In Decline. First of all, let’s look at the idea that these birds are super-abundant, as hack journalists and gull-haters would like you to think. As has now been pointed out many times (here at TetZoo and elsewhere), the species concerned are not just in decline, they’ve declined so much within recent decades that they’re now a cause for conservation concern. In the UK, the Herring gull L. argentatus – the species that hacks and haters mostly focus on – is a Red List species, its population now being at its lowest since recording began in 1969/70, and having declined by about 50% since the early 1990s (Madden et al. 2010, Joint Nature Conservation Committee 2014). The next most familiar species – the Lesser black-backed gull L. fuscus – has undergone a worrying population crash during this century. Similar trends are present in white-headed gulls elsewhere; the North American Herring/Smithsonian gull L. smithsonianus has declined by almost 80% since the 1960s.

Caption: a fine Lesser black-backed gull at a train station. Note the yellow legs, the small extent of the white spotting on the black tips to the primaries, and fairly dark mantle. Image: Darren Naish.

In view of this, it seems wrong to call for these birds to be sterilised (as some politicians have, apparently seriously, suggested), or for them to be lethally controlled or extirpated entirely. I may well be speaking from a position of privilege (I undoubtedly am, in fact, given that I live in a land where there are no big dangerous animals at all), but I want to live in a world where we’re alongside other species, not hell-bent on crushing them under heel into extinction. Urban gulls are an occasional menace for sure, but these aren’t animals that we should vilify or try to expunge. They need help; we should promote tolerance, not destruction.

Caption: a Bristolian Herring gull eating a feral pigeon, again at a train station. Did the gull kill the pigeon, or was the pigeon a victim of a train collision? I don’t know, but either is possible. Image: Darren Naish.

I should also add that urban gulls are important ecosystem service providers, eating waste, carrion and undesirable material (I won’t start listing it, but – oh, ok – it includes vomit and dog scat) left in the built environment by human action. They’re also important seed dispersers, playing this role in areas where other fruit-eating birds (yes, gulls eat fruit) are rare or absent (Iason et al. 1986, Magnusson & Magnusson 2000, Sekercioglu 2006).

Caption: a large group of white-headed gulls compete for food scraps in Lisbon, Portugal. Image: Darren Naish.

Why are people fixated on the idea that we have a ‘gull plague’, or that there are somehow ‘too many’ gulls? I think that a few factors may be at play. One is that gulls are both big and comparatively long-lived, meaning both that they’re way more obvious than small birds, most of which are ignored by the majority of people, and also seen repeatedly in the same areas. A single gull, hanging out on the same area of railway platform or beach promenade for perhaps more than 30 years (a Herring gull ringed in 1965 was still alive in 1997, and older individuals are now on record too), creates the impression of abundance.

There’s A Human Problem, Not A ‘Gull Problem’. Why are gulls so ubiquitous and – to hark back to the hack journalist take – problematic and pestilent? Is it because they’ve devised a clever plan to usurp humans and kill us all by pecking at the face? No, it’s because we’ve created ideal places for them to live, forage and breed thanks to our epic production of useable and edible waste, and our production of (mostly) predator-free, friendly places ideal for resting, feeding and breeding. We’ve also made life harder for them at coasts and seas thanks to development, pollution and industrial fishing. In short, the urban gull ‘problem’ is a direct product of the human problem.

Caption: there’s some degree of uncertainty as goes how reliable urban Herring gull counts are, but the overall trend over recent decades is certainly one of overall population decline. This graph is from the Joint Nature Conservation Committee Herring gull page. The dotted lines show 95% confidence limits. Image: JNCC (original here).

At the risk of repeating myself… yes, big gulls can be less than ideal neighbours. Yes, they’ll steal your chips or sandwiches if you’re dumb enough to hold those things aloft and be unaware of big animals watching you from nearby. Yes, they’ll potentially swoop at you or whack or bite you if you go close to their nests or chicks. Yes, they may even – very, very rarely – do such things as see small dogs and other pets as prey items. Yes, they shit. And, yes, they can be noisy and do their raucous calling at inconvenient times of the day or night.

Caption: white-headed gulls are slow to mature and have different plumage phases depending on age. It’s therefore typical to see birds of several different year stages at any one place where gulls hang out. This 1st winter Herring gull was photographed at Orton, Devon. Image: Darren Naish.

But I seriously question the idea that these often magnificent, slow-growing, long-lived and behaviourally fascinating birds are anything like the ‘problem’ that hack journalists would have us believe. I want to live in a world where there are other animals besides more humans and our domesticates, and the whole idea that gulls are a ‘problem’ is, frankly, tired bullshit that we should be done with.

Articles like this are possible because of the support I receive at patreon. Please consider supporting my research and writing if you don’t already, thank you so much.

Gulls and other charadriiform birds have been covered a few times on TetZoo before… though here’s your usual reminder that some of these articles are now paywalled, or have had their images removed.

• The godwit’s many bills, January 2007

• Why the Lion Grew Its Mane, a book review, November 2008

• To the Sahara in quest of dinosaurs (living and extinct), December 2008

• Mysterious channels of Alca torda, January 2009

• Kleptoparasitism at Westbury Manor, January 2009

• Mobile phones, medals, a doll's legs, an entire army... is there anything a gull won't swallow?, December 2009

• The incredible bill of the oystercatcher, July 2010

• Your Awesome Neighbourhood Herring Gull (And Its Many Cousins), September 2015

• Avocets in Flight and Phylogeny, October 2018

Refs - -

Iason, G.R., Duck, C. D. & Clutton-Brock, T. H. 1986. Grazing and reproductive success of red deer – the effect of local enrichment by gull colonies. Journal of Animal Ecology 55, 507-515.

Madden, B. & Newton, S. F. 2010. Herring gull (Larus argentatus). In Lloyd, C., Tasker, M. L. & Partridge, K. (eds) The Status of Seabirds in Britain and Ireland. T & AD Poyser, London, pp. 242-261.

Magnusson, B. & Magnusson, S. H. 2000. Vegetation on Surtsey, Iceland, during 1990–1998 under the influence of breeding gulls. Surtsey Research 11, 9-20.

Sekercioglu, C. H. 2006. Increasing awareness of avian ecological function. Trends in Ecology and Evolution 21, 464-471.

Young, H. G. 1987. Herring gull preying on rabbits. British Birds 80, 630.

Tell Me Something Interesting About Dunnocks

Never forget that animals familiar to you – the sort you see and hear every day, or every other day – may be exotic and exciting creatures to various of your fellow humans. And it’s for this reason that I’ve sometimes chosen to write about familiar, commonplace species I see every day, since I know that other people won’t be familiar with the animals concerned, nor even (in cases) be aware of their existence. Today I want to discuss a passerine bird I’ve long planned to write about: a cryptic, mostly brown species known generally and most commonly as the Dunnock Prunella modularis but increasingly as the Hedge accentor.

I’ve never found Dunnocks especially easy to photograph… but, then, I could say that about most of the birds I’ve tried to photograph. This one is living up to one of its vernacular names and standing on top of a (recently trimmed) hedge. Image: Darren Naish.

Actually, the ‘old’ name for this species here in the UK is ‘Hedge sparrow’. This name has mostly had its day. It’s naïve and quaint as well as wrong – we’ve mostly given up on the idea that ‘sparrow’ means ‘generic small brown bird’ – and it’s dying out because you look far smarter and more knowledgeable about birds if you know what an accentor is. Accentors are unique to northern Africa and Eurasia (excepting their introduction to New Zealand); all extant 13 species are included within the genus Prunella, though an argument has sometimes been made that Laiscopus should be recognised too (for the large, mountain-dwelling Alpine accentor P. collaris and Altai accentor P. himalayana). They’re mostly birds of mountainous places and temperate woodland, the Dunnock also occurring in suburban gardens and parks. Where do accentors belong within the passerine radiation? They’re part of Passeroidea and – ironically – very close to sparrows proper, but are outside the big passeroid clade that includes finches and New World nine-primaried oscines, termed Emberizoidea (Selvatti et al. 2015). Yes, they have a fossil record, but it only extends back to the Pliocene…. so far.

Substantially simplified cladogram of passeroid passerines, showing some of the main lineages. Accentors are close to true sparrows, wagtails and pipits and kin but are part of a paraphyletic assemblage of mostly thin-billed lineages (based on the phylogeny of Selvatti et al. (2015)). This cladogram uses images produced for my STILL in-prep textbook on the vertebrate fossil record, on which go here. Image: Darren Naish.

Dunnocks are mostly insectivorous but also eat worms and seeds, and mostly forage at ground level among leaf litter. Like so many birds that occur in western Europe, the Dunnock also occurs in part of northern Africa and in such parts of western Asia as the Caucasus and Iran. Some populations – those of the UK and elsewhere in western Europe, among others – are essentially sedentary while those of Scandinavia and western Russia migrate to the Mediterranean fringes and Asia Minor during the winter. Several subspecies have been named. These differ mostly in how dark they are, the form of Ireland, western Scotland and the adjacent islands (P. m. hebridium) being darkest, that of England and eastern Scotland (P. m. occidentalis) being palest.

Dunnocks are often seen in undergrowth, and thus in poor light. This photo (from 2006) shows one of the birds that used to live in my garden. Image: Darren Naish.

Flexible sexual systems. These days one of the things that most people interested in birds know about the Dunnock is that it’s notoriously flexible in breeding strategy. Some populations are monogamous (one male defends a territory inhabited by a single female), others are polygynous (where one male territory overlaps that of a few females, all of which mate with him and are defended by him from other males), and yet others are polygynandrous (where two males work together to defend the same territory, that territory containing several females, all of whom mate with the two males).

Females are often polyandrous and mate with the several males who share the same territory (these males have a dominance hierarchy of their own, but since they all mate with the same female even the ‘top’ male doesn’t necessarily father the greatest number of offspring). Seemingly because males know (or suspect) that the female in question has been mating with other males, females engage in a striking precopulatory display where she droops her wings, raises and vibrates her tail, and exposes her cloaca… which the male pecks, causing her to eject the contents (Davies 1983). The male will then guard the female to (in theory) ensure that she doesn’t mate with another male again.

I’ve seen a Dunnock do something that looked like soliciting on one occasion and have a bunch of poor photos of it, here are two of them. Image: Darren Naish.

Despite the familiarity of the Dunnock as a European garden bird, this weird and memorable behaviour wasn’t documented until 1933 in the book Evolution of Habit in Birds (this reporting an observation actually made in 1902), and even then by someone considered an outsider to technical ornithological research, namely Edmund Selous (Birkhead et al. 2014). The realisation that the precopulatory display and cloacal pecking was linked to sperm competition (Davies 1983), that extra-pair copulations were commonplace in ‘monogamous’ species, and that scientists might be able to test parentage of the resulting chicks via DNA analysis (Burke et al. 1989) didn’t arrive until the 1980s, and the Dunnock studies concerned occurred at about the same time as similar studies were documenting post-copulatory sexual selection and extra-pair copulations in birds and other animals.

David Quinn’s excellent illustration, showing the female’s precopulatory display. Image: (c) David Quinn. This drawing has appeared in Davies (1992) and Birkhead et al. (2014).

Some of you might remember seeing cloacal pecking in Dunnock featuring on TV for the first time in the 1998 BBC series The Life of Birds.

Female-female competition. In polygynous Dunnock populations, females compete for male attention and vie for territory with other females, at least some (and not the majority) of these competing females using complex songs to help attract ‘their’ male when he’s spending time with other females (Langmore & Davies 1997). They might sing as many as 60 times over the space of two days, and bouts of intense female-female competition can cause the male to move “to and fro in response to their trills, sometimes as often as every 10 or 20 seconds” (Langmore & Davies 1997, p. 887). In male passerines, elevated testosterone levels are linked to an increase in singing more. Could the same thing operate in females? Langmore et al. (2002) found that aggression among competing polygynous and polygynandrous females caused a rise in their testosterone levels, with this rise being linked to female calling and singing.

Use of complex, competitive singing by females is not unique to the Dunnock but was first documented in another accentor, the habitually polygynandrous Alpine accentor (Langmore et al. 1996). It’s increasingly well known that female-female competition is present and even important in animals (it’s key to the work I and colleagues have published on mutual sexual selection), but the case studies where it’s well documented aren’t all that familiar among biologists at large. Accentors, it turns out, are among the best of case studies.

The face a of a Dunnock. There are some similarities here with wagtails and pipits, and with sparrows and finches and their kin. Image: Darren Naish.

Having mentioned variation in female vocalisations, it’s worth noting that male Dunnocks are variable too, their singing changing (‘switching’, to use ornithological parlance) to an increased rate when they’re searching for fertile females. Rapid song switching appears to be liked by females, who are more likely to solicit matings when they hear a male produce multiple song types (Langmore 1997).

Dunnocks encountered in the UK. The most striking plumage feature of this bird - the prominent streaking on its mantle and flanks - is not obvious in all views. Image: Darren Naish.

So many copulations. Perhaps unsurprisingly in view of all this, Dunnocks are sexually active little animals with a high reproductive output, by which I mean that they can mate over 100 times in a day, each copulation taking less than a second. A thousand copulation events might have occurred over the span of time in which a single egg clutch was produced, the high number of solicitations by females seemingly being more to do with securing male interest in provisioning the clutch than in winning successful fertilisation (Davies et al. 1996). In polygynandrous populations, it therefore makes sense – as a male – to turn down at least some female solicitations,  and to help less at the nest than males do in monogamous and other populations.

The possibilities open to these birds are diverse, and all have different knock-on effects as goes which sex has the ‘upper hand’ and what these strategies could mean in evolutionary terms. I haven’t covered half of the complexity here anyway – you could literally write a whole book on this stuff, and in fact Nick Davies did exactly this, back in 1992 (Davies 1992).

Nick Davies’s 1992 book is the classic work on these birds. Hey, there’s that illustration by David Quinn again.

That’s where we’ll end for now. This is yet another of those TetZoo articles that’s been planned and in a partially written state for years. Big thanks to Matt Wedel for helping to collect the relevant literature – something he did back in 2006! Yes, a lot of slow-burn stuff here at TetZoo.

If you enjoyed this article and would like to see me do more, please consider supporting this blog (for as little as $1 per month) at patreon. The more support I receive, the more financially viable this project becomes and the more time and effort I can spend on it. Thank you :)

 For previous TetZoo articles on passerines, see…

• Great tits: still murderous, rapacious, flesh-rending predators!, February 2013

• For The Love of Crows, October 2015

• Thoughts on the Passerine Tree, 2016, October 2016

• A Battle Among Blue Tits, February 2018

• Birdwatching in Suburban China, May 2019

Refs - -

Birkhead, T., Wimpenny, J. & Montgomerie, B. 2014. Ten Thousand Birds: Ornithology Since Darwin. Princeton University Press, Princeton.

Burke, T., Davies, N. B., Bruford, M. W. & Hatchwell, B. J. 1989. Parental care and mating behaviour of polyandrous dunnocks Prunella modularis related to paternity by DNA fingerprinting. Nature 338, 249-251.

Davies, N. B. 1983. Polyandry, cloaca-pecking and sperm competition in dunnocks. Nature 302, 334-336.

Davies, N. B. 1992. Dunnock Behaviour and Social Evolution. Oxford University Press, Oxford.

Davies, N. B., Hatchwell, B. J. & Langmore, N. E. 1996. Female control of copulations to maximize male help: a comparison of polygynandrous alpine accentors, Prunella collaris, and dunnocks, P. modularis. Animal Behaviour 51, 27-47.

Langmore, N. E. 1997. Song switching in monandrous and polyandrous dunnocks, Prunella modularis. Animal Behaviour 53, 757-766.

Langmore, N. E., Cockrem, J. F. & Candy, E. J. 2002. Competition for male reproductive investment elevates testosterone levels in female dunnocks, Prunella modularis. Proceedings of the Royal Society, London Series B 269, 2473-2478.

Langmore, N. E. & Davies, N. B. 1997. Female dunnocks use vocalizations to compete for males. Animal Behaviour 53, 881-890.

Langmore, N. E., Davies, N. B., Hatchwell, B. J. & Hartley, I. R. 1996. Female song attracts males in the alpine accentor Prunella collaris. Proceedings of the Royal Society, London Series B, 263, 141-146.

Selvatti, A. P., Gonzaga, L. P. & Russo, C. A. de M. 2015. A Paleogene origin for crown passerines and the diversification of the Oscines in the New World. Molecular Phylogenetics and Evolution 88, 1-15.

The World’s Best Books on Woodpeckers

I really like woodpeckers. This large, widespread group of around 240 living species includes the wrynecks, piculets and true or typical woodpeckers and includes species ranging from 7 to 60 cm in length. Woodpeckers are famous for their wood-excavating specialisations and ability to cling and climb on vertical substrates, but they’re diverse and not all species have these features. Here, I’ll resist the urge to talk about the birds that much and will instead provide brief comments on some of the best books written on these charismatic and fascinating animals.

This is one of the two woodpecker species I see on a regular basis: Green woodpecker Picus viridis (this photo from March 2016). All my photos are bad. Image: Darren Naish.

Winkler et al.’s Woodpeckers: A Guide to the Woodpeckers, Piculets and Wrynecks of the World. Winkler et al. (1995) is the woodpecker instalment in the famous Pica Press book series: these books feature an introductory section on the anatomy and systematics of the group concerned, a colour plate section (in this case, with art by David Nurney), and a species-by-species text section. The book is definitive and I’ve used it a lot. The text summarises knowledge on range, identification, habits, foot, breeding and more, and references are provided.

Like most people seriously interested in birds, I’ve amassed a decent collection of the Helm/Pica Press books in the same series, but I’m some way from owning all of them. Insert typical complaint about recently published bird books being prohibitively expensive.

The Helm/Pica Press bird books (oops, plus a few others) in the Tet Zoo Towers library. Image: Darren Naish.

Alexander Skutch’s Life of the Woodpecker. Skutch (1985) is a large (near ‘oversize’) hardback book, beautifully illustrated in colour throughout by the very good paintings of Dana Gardner. The book is separated into sections that cover the various aspects of woodpecker behaviour and ecology; there’s also a brief introduction to woodpeckers as a whole and a taxonomic list of recognised species at the back. Overall, the book is a good introduction to our knowledge of woodpeckers and everything about them, but it’s the artwork that makes it really worth getting.

Left: Fiery-billed aracari (Pteroglossus frantzii) vs Pale-billed woodpecker (Campephilus guatemalensis). Right: Imperial Campephilus imperialis. Just two of the many excellent illustrations by Dana Gardner included in Skutch (1985). Image: Dana Gardner/Skutch (1985).

Gerard Gorman’s Woodpeckers of the World. I absolutely love field guides, often for the art more for the utility, and in part because I love the convention of showing closely related species arranged together on the same plate. But despite those things, we still often need to see photographs of the animals we’re interested in. Gorman (2014) is a photographic guide to the world’s living woodpecker species, each being illustrated by at least a few photos (though read on). The text is good too: each species has a short section covering identification, range, variation and so on. The photos are excellent. It’s a must-have if you’re seriously interested in these birds.

Are all species illustrated by photos? What about the Ivory-billed woodpecker in the room… by which I mean: what about photos of the Ivory-billed Campephilus principalis and Imperial C. imperialis? No photos, only text.

Tim Gallagher’s Imperial Dreams. I reviewed this book at TetZoo back when it was new in 2013 (but good luck finding the article now; it’s been ruined by its hosters, like all stuff at ver 2 and ver 3). I’m not that great a fan of travelogue-type books on natural history, but I do really like Imperial Dreams. One of the world’s most spectacular woodpeckers is – or, was – the Imperial woodpecker of the Sierra Madre Occidental, a pine forest giant that seems to have dwindled to extinction somewhere between the late 1950s and … 1980s? 90s? No-one knows exactly when this bird went extinct, and its persistence was rumoured as recently as the 1990s.

Gallagher (2013) charts an effort to search for continuing traces for this species. A lot of information on the bird itself is included, but the human story relevant to the region is fascinating too. If you like woodpeckers, the book is well worth getting hold of. I should finish by adding that Gallagher also wrote The Grail Bird: Hot on the Trail of the Ivory-Billed Woodpecker, a volume I haven’t yet read.

Books on woodpeckers. There are others… Image: Darren Naish.

Woodpeckers have been covered several times on TetZoo, but - as usual (is this getting boring now?) - they’ve been ruined by removal of images at ver 2 (the ScienceBlogs years) and ver 3 (the SciAm years). Anyway…

• Woodpeckers: barbed tentacles and the avoidance of brain injury, August 2008

• Tet Zoo Bookshelf: van Grouw’s Unfeathered Bird, Bodio s Eternity of Eagles, Witton’s Pterosaurs, Van Duzer’s Sea Monsters on Medieval and Renaissance Maps!, June 2013

Refs - -

Gallagher, T. 2013. Imperial Dreams: Tracking the Imperial Woodpecker Through the Wild Sierra Madre. Atria Books, New York.

Gorman, G. 2014. Woodpeckers of the World: A Photographic Guide. Firefly Books, Buffalo.

Skutch, A. 1985. Life of the Woodpecker. Ibis Publishing Company, Santa Monica.

Winkler, H., Christie, D. A. & Nurney, D. 1995. Woodpeckers: A Guide to the Woodpeckers, Piculets and Wrynecks of the World. Pica Press, Mountfield, UK.