Once again it’s time to continue with my slow-burn zoo review series. I’ve just returned from a trip to Tokyo, you see, and while there I visited two zoos. Today we look at the first of them: Ueno Zoological Gardens (usually just called Ueno Zoo), located in Ueno Park in Taito City, central Toyko…
New Species Round-up for 2023, Part 2
In the previous article we looked briefly at those new amphibian and mammal species named during 2023. This time we skip ahead to reptiles… including birds because – yes – birds are reptiles in the phylogenetic sense)….
Birdwatching in Tajikistan, Part 2
Birdwatching in Tajikistan, Part 1
Alan Feduccia’s Romancing the Birds and Dinosaurs: Forays in Postmodern Paleontology
Laysan Ducks: Not as Degenerate as People Used to Think
The Great Florida Cassowary Relocation Event of 2023
Controversies in Ratite and Tinamou Evolution (Part I)
Surprising Diet of the House Sparrow
Otidiphaps the Pheasant-Pigeons
Inside the Cassowary's Casque, Updated for 2022
Chiffchaffs and What Are 'Old World Warblers' Anyway?
Pete Dunne and Kevin T. Karlson’s Gulls Simplified: A Comparative Approach to Identification
Painted-Snipes
Kirk W. Johnson’s 2018 The Feather Thief, a Review
Why the World Has to Ignore David Peters and ReptileEvolution.com
The Dodo in Life
You’re already highly familiar with the Dodo Raphus cucullatus, and images of what this animal looked like in life are present in a vast number of books, popular sources and museum displays. What might not be so familiar to you is that the Dodo’s life appearance has been the subject of long-standing debate, that many familiar ideas about its appearance are very likely wrong, and that – even today – we’re uncertain about several details.
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.
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.
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.
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.
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.
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.
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).
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.
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.
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.
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.
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).
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.
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.
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.
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.
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.
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).
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.
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.
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.
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.
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
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.
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).
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).
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?
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.
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.
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.
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).
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.
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.
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.
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
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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.
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.
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.
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.
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.
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.
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).
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).
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.
For previous TetZoo articles on passerines, see…
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 - -
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.