Tetrapod Zoology

Titan-hawks and other super-raptors

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Keeping promises isn’t always easy, but – following what is hopefully a forgiveable hiatus – here we get back to that short series on obscure island-dwelling, recently extinct animals. It started with a map of the Caribbean. Then we got through (some of the) island otters and canids, and then more of the canids… the good news is that here we have that long-awaited, much-asked-for ‘titan-hawks and monster pigeons’ article. The bad news: I got carried away on the titan-hawks and other raptors, and the pigeons will have to wait, sorry…

It now seems that big raptors were important predators on islands worldwide until very recently. As usual, the extinction of these birds can probably (although not certainly) be blamed on anthropogenic causes: hunting, persecution, habitat disruption and/or ecological disturbance. Species that are still with us, like the widespread Golden eagle Aquila chrysaetos and the Imperial eagle A. heliaca were found on Mallorca and Corsica during the Pleistocene*, and a particularly large form of Golden eagle – named as the subspecies A. c. szimurgh – inhabited Pleistocene Crete. Alcover & McMinn (1994) noted that these big eagles would have preyed on the endemic Mediterranean artiodactyls, like the dwarf megacerine deer Megaloceros cazioti, the weird Balearic goat Myotragus balearicus and the Cretan deer Candiacervus, though I don’t know whether there’s any direct evidence for these inferred predatory relationships.

* What used to be called the Imperial eagle is now two species: the Eastern imperial eagle of eastern Europe and Asia, and the Spanish imperial eagle A. adalberti of the Iberian Peninsula. I don’t know which of the two the extinct Mediterranean birds belonged to.

The biggest eagle part II

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Sea eagles (Haliaeetus) formerly inhabited Mediterranean islands and the Hawaiian islands during the Pleistocene and/or Holocene. Madagascar had the large, lemur-hunting Stephanoaetus mahery and New Zealand had the biggest eagle we know of, the awesome Haast’s eagle Harpagornis moorei (though read on). I previously wrote about Haast’s eagle on Tet Zoo ver 1 here but never got round to finishing things and publishing part II, so I may as well get that over and done with here. It’s old news now, but back in 2005 the big deal was that Haast’s eagle – traditionally given its own genus (Harpagornis) and thought to be close to or part of the big-bodied Aquila eagle clade (Holdaway 1992) – turns out to be part of a clade of small-bodied eagles. This discovery means that we have to revise our ideas on the affinities of the giant eagle, but also shows that a totally unexpected and incredible thing happened during the evolutionary history of this bird [adjacent image shows John Megahan's much-reproduced reconstruction of Haast's eagle vs moa pair].

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As demonstrated by Bunce et al. (2005), DNA from Haast’s eagle indicates that the species is actually nested within Hieraaetus – the hawk-eagles – and hence should be renamed Hieraaetus moorei. All other Hieraaetus species are quite small (they weigh about 1 kg and have wingspans of c. 1.2 m: Haast’s eagle weighed up to 13 kg and had a wingspan of c. 2.6 m), so the ancestor of Haast’s eagle must have been small too. It’s inferred that – on arriving on a landmass lacking competitors and with an abundance of large, terrestrial prey – a small Hieraaetus species rapidly evolved into a powerful giant. We know from well documented taphonomic evidence that Haast’s eagle could and did kill even the very biggest of the contemporary moa, and unlike big eagles in continental environments it could probably get away with gorging itself at a carcass without having to worry about flying off in a hurry [adjacent image shows Booted eagle H. pennatus].

Giant buteonines from Gargano

During the late Miocene or early Pliocene (this age depends on which source you consult), what is now the Gargano Peninsula on the Adriatic coast of southern Italy formed an island archipelago inhabited by numerous island-endemic tetrapods. Among these were exceptionally large dormice, hamsters and mice, the giant long-skulled Deinogalerix hedgehogs (there are five species, not just one as you might think from the popular literature), an otter, European pikas, and the multi-horned artiodactyl Hoplitomeryx.

Rarely mentioned, however, are the buteonine hawks Garganoaetus freudenthali and G. murivorus (Ballman 1973, 1976). G. freudenthali was about the size of a Golden eagle while G. murivorus was probably hawk-eagle sized. What might be two additional, buzzard-sized Garganoaetus species are also known. Several features distinguish Garganoaetus from other hawks and eagles, most notably its peculiar tarsometatarsus where the trochlea for digit 4 extended as far distally as the other trochleae. On the basis of various (other) tarsometatarsal characters, Garganoaetus was argued by Ballmann (1973) to be a buteonine: that is, a member of the accipitrid group that includes true buzzards (Buteo) and their close relatives (buzzard-eagles, crab-eater hawks, solitary eagles, Harris hawk Parabuteo unicinctus, Lizard buzzard Leucopternis schistacea and others). Buteonines are mostly New World raptors; they are good at soaring, have long, broad wings and tend to have short tails. A recent study supported their monophyly (Lerner & Mindell 2005).

Large barn owls were also present on Gargano: Tyto robusta was described by Ballman (1973) as similar in size to a Snowy owl Bubo scandiacus while T. gigantea was even larger than a Eurasian eagle owl B. bubo, making it the largest known barn owl of all time. Some internet sources say that T. gigantea was twice as big as B. bubo: so far as I can tell from Ballman (1973) – it’s in German – he only said that it was larger than B. bubo. There were also smaller barn owls (T. santicalbani), some additional owls which remain poorly known, a species of Palaeortyx (a pheasant also known from Miocene France), a pigeon, swift, and warbler (Ballmann 1973, 1976). The Gargano avian assemblage has more recently been studied by Pavia and Ghlich (2004). In addition to the taxa described by Ballmann, they also reported an ibis, a duck, a small raptor, rails, a new bustard, and shorebirds.

West Indian giant crab-eater hawks

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Garganoaetus freudenthali is interesting in being the size of a big eagle, even though it was apparently more closely allied to buzzards and other buteonines. Similar in some respects are the so-called titan-hawks and other large raptors of the West Indies. The most oft-mentioned of these extinct raptors is the species originally described as Aquila borrasi Arredondo, 1970. It comes from the Pleistocene of Cuba and was even noted by Arredondo (1976) as being similar in size and morphology (in tarsometatarsal anatomy anyway) to Garganoaetus; Arredondo also noted that A. borrasi was longer in the tarsometatasus than any living eagle, with a longer and more robust femur than any living eagle, and with ungual phalanges about twice as large as those of a Golden eagle! Despite these proportions, the tarsometatarsi of A. borrasi are more gracile than those of Aquila eagles, so it probably wasn’t able to tackle large-bodied mammalian prey as Golden eagles and other large Aquila species can [adjacent image shows Savanna hawk Buteogallus meridionalis: read on for relevance].

During my most formative years I always assumed that A. borrasi was a relatively well known species, all because of a Cuban stamp – shown at the top of the article – which depicts a nice life restoration of this species. Alas, that life restoration is but a fiction, and nothing more than a souped-up version of Arthur Singer’s painting from the 1960s of an Ornate hawk-eagle Spizaetus ornatus swooping in to catch an iguana. In fact, A. borrasi has always been poorly known and mysterious. Arredondo’s original classification of A. borrasi as part of Aquila reflects the common usage of the latter generic name as a ‘waste-basket’ for various raptors that are not really close relatives, and it’s been suggested several times that Arredondo’s Cuban raptor is actually more similar to Buteogallus, the four (or five) Central and South American buteonine hawks sometimes called the crab-eaters, or mangrove hawks, or black hawks. Olson & Hilgartner (1982) then suggested that A. borrasi might belong to Titanohierax, a genus named by Alexander Wetmore in 1937 for the species Titanohierax gloveralleni (more on that one in a minute). A. borrasi has therefore been referred to as Titanohierax borrasi in the more recent literature (e.g., Olson & Hilgartner 1982, Milberg & Tyrberg 1993, Alcover & McMinn 1994).

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However, the big news is that a new paper on this taxon has just appeared (Surez & Olson 2007), and it argues that…. A. borrasi isn’t just similar to Buteogallus, it is a Buteogallus, albeit a gigantic species about one-third larger than the largest living species, the Great black hawk B. urubitinga [shown in adjacent image]. Buteogallus is an interesting raptor for various reasons (Lerner & Mindell 2005, do Amaral et al. 2006); I’ll come back to it later. If Buteogallus borrasi, as it’s now known, was essentially a giant version of the Great black hawk, it presumably lived in a similar way: a sluggish, soaring hawk of mangroves and heavily wooded riverine habitats that preyed on crustaceans, lizards and large insects.

The Bahaman titan-hawk

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Titanohierax gloveralleni, the type species of Titanohierax (sometimes called the Bahaman titan-hawk), was first named by Alexander Wetmore in 1937 for fragmentary specimens from Pleistocene deposits on Little Exuma in the Bahamas (Little Exuma and Great Exuma are north-east of central Cuba, west of Andros Island, and south of New Providence and Eleuthera). Additional material was later reported from New Providence by Olson & Hilgartner (1982). Burness et al. (2001) estimated the mass of the Bahaman titan-hawk as 7.3 kg, which would make it similar in size to the biggest living eagles, the Philippine eagle Pithecophaga jefferyi and Harpy eagle Harpia harpyja, according to some measurements anyway (upper weights of 8 or 9 kg are given for females of these two species, but data is poor and these figures may be exceptional).

Bits and pieces referred to the genus Titanohierax (but not to the species T. gloveralleni) have been reported from Hispaniola and Grand Cayman, with the implication being that these large raptors were apparently widespread throughout the West Indies. However, now that some material previously thought to belong to Titanohierax is now thought referable to Buteogallus, some of these specimens might require reidentification. What sort of raptor was T. gloveralleni? Olson & Hilgartner (1982) noted that it might be particularly closely related to Geranoaetus melanoleucos, the Black-chested buzzard eagle [shown in image above]. If this is correct then T. gloveralleni would be another buteonine in close phylogenetic proximity to Buteogallus and other buzzard-like raptors (Lerner & Mindell 2005).

Even more mysterious than T. gloveralleni is the Cuban giant-hawk Gigantohierax suarezi Arredondo & Arredondo, 2002 (the paper that first named this species is dated 1999, but wasn’t published until 2002). Apart from the fact that it was big and endemic to Cuba, not much is known about it. The type specimen is a particularly big, strongly pneumatized left femur (Arredondo & Arredondo 2002), though material referable to this species has now been reported from three cave sites. Uncertainty remains as to the affinities of Gigantohierax, though it may well have been another buteonine.

The Woodward ‘eagle’

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The most recently identified West Indian large raptor is Amplibuteo woodwardi (sometimes called the Woodward eagle), but it’s not a newly named species. Amplibuteo was originally described for the species A. hibbardi from the Pleistocene Talara Tar Seep of Peru, and in the same paper it was also argued that Morphnus woodwardi from Rancho La Brea, originally described in 1911, should also be identified as a species of Amplibuteo. More recently, Amplibuteo has been reported from the Pliocene of Florida and Arizona, and it was still living in Florida during the Pleistocene. The members of this genus therefore appear to have been widespread across North America. Indeed the recognition of A. woodwardi on Cuba (Surez 2004) indicates that it crossed from the North American mainland to the Greater Antilles, and that it may await discovery on islands other than Cuba [adjacent pic is taken from here and labelled as that of a Woodward eagle, hence my use of it here. However, it's mislabelled and is in face a Merriam's teratorn Teratornis merriami. Thanks to Bill Unzen for bringing this to my attention].

A. woodwardi was probably similar in size to Buteogallus borrasi and Titanohierax gloveralleni (i.e., big), but it apparently differed from B. borrasi at least in being a bird of semi-arid grassland habitats, where it presumably preyed mostly on reptiles and smaller mammals. Given that complete skeletons are known, there should be accurate data on its size and inferred wingspan, but if such data exists I haven’t seen it. What would Amplibuteo have looked like when alive? In their description of the new Pliocene species A. concordatus (from Florida and Arizona), Emslie & Czaplewski (1999) suggested that Amplibuteo might be congeneric with Harpyhaliaetus, the extant Neotropical solitary eagles. The two solitary eagle species are broad-winged, very short-tailed, dark grey or blackish eagles with occipital crests. They are noisy, often eat snakes, and the Crowned solitary eagle (H. coronatus) is said in some accounts to be partially crepuscular and to hunt skunks, which makes it interesting to say the least. It would be very neat if A. woodwardi was at all like this. If Emslie & Czaplewski (1999) were right about Amplibuteo being close to Harpyhaliaetus, then – yet again – these raptors were buteonines [image below shows Crowned solitary eagle H. coronatus].

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So, what with all these big buteonines, the West Indian avifauna has proved really interesting. But remember that the prehistoric Caribbean raptor fauna was considerably more diverse than this: the big West Indian buteonines lived alongside small buteonines (including true buzzards), accipiters, ospreys, true falcons, caracaras, barn owls, burrowing owls, various other extinct owls (some of which were very large and either poorly flighted or flightless), New World vultures, and teratorns (although members of these groups did not necessarily all live on the same island at the same time). Where are they now? Exactly why so many of them became extinct remains relatively unstudied, but it is likely that the loss of presumed prey species – the various terrestrial rodents and other mammals, for example – was a major factor in their decline. Other factors were involved too, but I’m not about to discuss them now.

Finally – that’s another ‘to do’ ticked off the list. Just pandas, phytosaurs, astrapotheres, rhynchosaurs, pyrotheres, giraffids, Piltdown, amphisbaenians, beluwhals, palaeophiids, meiolaniids, de-hominization, knuckle-walking, tortoises, kinglets, Eotyrannus and… monster pigeons to go. Watch this space, I’ll do them all tomorrow. Yeah.

Refs – -

Alcover, J. A. & McMinn, M. 1994. Predators of vertebrates on islands. BioScience 44, 12-18.

Arredondo, O. 1976. The great predatory birds of the Pleistocene of Cuba. Smithsonian Contributions to Paleobiology 27, 169-187.

- . & Arredondo, C. 2002. Nuevos gnero y especie de ave fsil (Falconiformes: Accipitridae) del Cuaternario de Cuba. Poeyana 470-475, 9-14.

Ballman, P. 1973. Fossile Vgel aus dem Neogen der Halbinsel Gargano (Italien). Scripta Geologica 17, 1-75.

- . 1976. Fossile Vgel aus dem Neogen der Halbinsel Gargano (Italien), zweiter Teil. Scripta Geologica 38, 1-59.

Bunce, M., Szulkin, M., Lerner, H. R. L., Barnes, I., Shapiro, B., Cooper, A. & Holdaway, R. N. 2005. Ancient DNA provides new insights into the evolutionary history of New Zealand’s extinct giant eagle. PLoS Biology 3 (1), e9.

Burness, G. P., Diamond, J. & Flannery, T. 2001. Dinosaurs, dragons, and dwarfs: the evolution of maximal body size. Proceedings of the National Academy of Sciences 98, 14518-14523.

do Amaral, F., Miller, M., Silveira, L., Bermingham, E. & Wajntal, A. 2006. Polyphyly of the hawk genera Leucopternis and Buteogallus (Aves, Accipitridae): multiple habitat shifts during the Neotropical buteonine diversification. BMC Evolutionary Biology 6, 10 doi:10.1186/1471-2148-6-10

Emslie, S. D. & Czaplewski, N. J. 1999. Two new fossil eagles from the Late Pliocene (late Blancan) of Florida and Arizona and their biogeographic implictations. Smithsonian Contributions to Paleobiology 89, 185-198.

Holdaway, R. N. 1994. An exploratory phylogenetic analysis of the genera of the Accipitridae, with notes on the biogeography of the family. In Meyburg, B.-U. & Chancellor, R. D. (eds) Raptor Conservation Today. WWGBP/The Pica Press, pp. 601-649.

Lerner, H. R. L. & Mindell, D. P. 2005. Phylogeny of eagles, Old World vultures, and other Accipitridae based on nuclear and mitochondrial DNA. Molecular Phylogenetics and Evolution 37, 327-346.

Milberg, P. & Tyrberg, T. 1993. Nave birds and noble savages – a review of man-caused prehistoric extinctions of island birds. Ecography 16, 229-250.

Olson, S. L. & Hilgartner, W. B. 1982. Fossil and subfossil birds from the Bahamas. Smithsonian Contributions to Paleobiology 48, 22-60.

Pavia, M. & Ghlich, U. B. 2004. Revision of the fossil bird association of the neogene of the Gargano (Apulia, SE Italy). In Buffetaut, E. & Le Loeuff, J. (eds) Sixth International Meeting of the Society of Avian Paleontology and Evolution, Abstracts. Quillan, France. 28th September – 3rd October, 2004, pp. 52-53.

Surez, W. 2004. The identity of the fossil raptor of the genus Amplibuteo (Aves: Accipitridae) from the Quaternary of Cuba. Caribbean Journal of Science 40, 120-125.

- . & Olson, S. L. 2007. The Cuban fossil eagle Aquila borrasi Arredondo: a scaled-up version of the Great black-hawk Buteogallus urubitinga (Gmelin). Journal of Raptor Research 41, 288-298.

Comments

  1. #1 Dave Hone
    January 28, 2008

    Best hurry up Darren. It is already 8pm here, so only 4 hours until tomorrow kicks in and just the 17 articles to get done…. ;-)

  2. #2 Ian
    January 28, 2008

    Can you add giant owls to your list of things to talk about?

  3. #3 Jerzy
    January 28, 2008

    Cool creatures!

    It’s sad that nobody did biomechanic studies how these eagles hunted their prey.

    BTW, hawaiian sea eagle story is interesting. Subfossil bones unrecognizable from white-tailed/bald eagle were found. Recently, vagrant bald eagle turned up in Hawaii, trying to restart evolution again.

  4. #4 Raymond
    January 28, 2008

    Multituberculates!Multituberculates dammit!

  5. #5 Lars Dietz
    January 28, 2008

    Very interesting post!

    Since the usual generic classification of the “booted eagle” (Aquila/Hieraaetus/Spizaetus etc.) clade seems to have so little to do with their actual phylogeny, I think it would be best to unite them all into Aquila, as has been done already in the newest edition of the “Kompendium der V�gel Mitteleuropas”. (One spelling correction: it’s Aquila heliaca.)

    “Tyto gigantea was described by Ballman (1973) as similar in size to a Snowy owl Bubo scandiaca while T. gigantea was even larger than a Eurasian eagle owl B. bubo”
    I think the first one should be T. robusta.
    You’ve understood Ballmann’s description correctly, it indeed only says that Tyto gigantea was larger than Bubo bubo, not twice as large. It includes a table with measurements compared to T. alba guttata, and I took the length of the holotypical tibiotarsus, assumed the same proportions as Tyto alba, and got a length of about 75 cm for T. gigantea. Much less than twice the size of Bubo bubo.
    Here is a list of fossil owls, with PDFs of all thed original descriptions:
    http://nrm.museum/ve/birds/sape/GlobalOwlProject/Fossil_owls/Fossil.html

    Lerner & Mindell find that Harpyhaliaetus is actually nested inside Buteogallus, which would mean that it (and Amplibuteo too, if it’s really related) should also be included in Buteogallus.

  6. #6 shiva
    January 28, 2008

    Barn owls bigger than, potentially even *twice* as big as, eagle owls? :O

    You’ve got me thinking about cryptids like Mothman and Owlman now…

    Where does the figure of 2.6m wingspan for Haast’s eagle come from? That seems kind of small for a 13kg raptor to me, given that my field guide to European birds says that living species of both Haliaeetus and Aquila can get that big in wingspan, and they weigh under half as much…

    Didn’t New Zealand also have a giant harrier?

    Anyway, awesome stuff as usual. I’m eagerly awaiting the monster pigeons…

  7. #7 David Marjanovi?
    January 28, 2008

    Larger than an eagle owl is seriously scary.

    Haast’s eagle had quite short wings and must have flown very fast, killing by impact.

    Just pandas, phytosaurs, astrapotheres, rhynchosaurs, pyrotheres, giraffids, Piltdown, amphisbaenians, beluwhals, palaeophiids, meiolaniids, de-hominization, knuckle-walking, tortoises, kinglets, Eotyrannus and… monster pigeons to go.

    Temnospondyls.

  8. #8 Hai~Ren
    January 28, 2008

    It’s amazing that so many of these large raptors lived so recently, possibly making contact with the first human explorers, yet they’re not as high-profile as the mammalian megafauna (aside from the Haast’s eagle).

  9. #9 Mike Keesey
    January 28, 2008

    De-hominization?

    Is this about Homo floresiensis?

  10. #10 Dr Vector
    January 28, 2008

    Just pandas, phytosaurs, astrapotheres, rhynchosaurs, pyrotheres, giraffids, Piltdown, amphisbaenians, beluwhals, palaeophiids, meiolaniids, de-hominization, knuckle-walking, tortoises, kinglets, Eotyrannus and… monster pigeons to go.

    Yay! The promise list returns. It’s been a while.

    I’ll second David M. on the temnospondyls, and suggest microsaurs and all the other groups of basal tetrapods that have been proposed at one time or another as potential ancestors of extant amphibs. In fact, a whole series of posts on amphibian origins would be nice.

    Also, some posts on the natural history of animal sleep would rock pretty hard too.

    You know, in your copious spare time. :-)

  11. #11 Zach Miller
    January 28, 2008

    Awesome article. I LOVE eagles and hawks. While at the San Diego Zoo, I saw a giant eagle with exaggerated tufts of feathers on its head (can’t…remember…the name!). At any rate, the sucker was HUGE, and I have no doubt that, if it wanted to, that eagle could have killed me. I have great respect for animals that can kill me.

  12. #12 Darren Naish
    January 28, 2008

    Many thanks as always to all for comments. Oh yes, more temnospondyls. And lepospondyls, and lysorophians, tetrapod sleep behaviour, MTBs… and giant owls. Jeeeee-sus. You can see why I stopped doing the ‘coming soon’ thing.

    Thanks in particular to Lars for pointing out bonehead errors. On Hieraaetus, Spizaetus etc., have you seen…

    Haring, E., Kvaloy, K., Gjershaug, J.-O., Rov, N. & Gamauf, A. 2007. Convergent evolution and paraphyly of the hawk-eagles of the genus Spizaetus (Aves, Accipitridae) – phylogenetic analyses based on mictochondrial markers. Journal of Zoological Systematics & Evolutionary Research 45, 353-365.

    This study doesn’t clear up the Hieraaetus + Aquila mess, but did show that, of all those hawk-eagles previously included within Spizaetus, only Cassin’s hawk-eagle S. africanus is part of the Hieraaetus + Aquila clade and hence should be named Aquila africana. I went to a talk by Michael Bunce, incidentally, where it was concluded that Hieraaetus and Aquila should probably be regarded as one genus.

    And on Buteogallus and its paraphyly with respect to other buteonines, I deliberately avoided this because I knew it would involve a lengthy discussion of do Amaral et al. (2006: ref above). Sometimes I simply have to avoid discussing a specific area, otherwise I won’t get the job done.

    Shiva: regarding proportionally short wingspan of Haast’s eagle – as David said, it was a round-winged, forest bird, see Worthy & Holdaway’s book for the full story. Was there a giant New Zealand harrier? Yes there was, please see my ver 1 article here.

    De-hominization: not Homo floresiensis in mind, but H. sapiens. My research on this subject has been slowed by problems with the literature. More one day.

    Zach: there are a few big crested eagles that are formidable and quite capable of causing serious damage to people. The coolest IMHO is the African crowned eagle Stephanoaetus coronatus: they have these at San Diego and in fact were the first zoo in the world to breed the species I think. San Diego Zoo also has Harpy eagles Harpia harpyja (and in fact San Diego was the first US zoo to breed the species). To my knowledge, no-one has documented a human death caused by a Harpy; an African crowned, however, has killed an 8-yr old child.

    For anyone really interested in big eagles and their abilities, please go to Tet Zoo ver 1 and put ‘Aquila’ in the search box.

  13. #13 Eike
    January 28, 2008

    “You’ve understood Ballmann’s description correctly, it indeed only says that Tyto gigantea was larger than Bubo bubo, not twice as large.”

    To avoid confusion, use “longer” and “heavier” always, and remember Bergmann’s rule. The largest Gargano individuals *might* just have been twice as heavy as a smallish _Bubo bubo_. All other things being equal, probably not though, as being the volant barn-owls they were, they were probably a bit more slender than an eagle-owl.

    “Didn’t New Zealand also have a giant harrier?”

    _Circus eylesi_, the females were eagle-sized (though not as big as a Golden or _Haliaeetus_).

    “Where does the figure of 2.6m wingspan for Haast’s eagle come from? That seems kind of small for a 13kg raptor to me, given that my field guide to European birds says that living species of both Haliaeetus and Aquila can get that big in wingspan, and they weigh under half as much…”

    See:
    Brathwaite, D. H. (1992): Notes on the weight, flying ability, habitat, and prey of Haast’s Eagle (Harpagornis moorei). Notornis 39(4): 239-247. http://www.notornis.org.nz/free_issues/Notornis_39-1992/Notornis_39_4_239.pdf

    Argues from trunk skeleton proportions and inferred hunting skills that Haast’s Eagle was almost certainly very short-winged for its size, but possibly decidedly big-tailed.

    Especially _Haliaeetus_ has quite slender and long wings. Looks very much like a true vulture (Old World minus Lammergeier and Egyptian). As if they had arthritis in the wrists and can’t bend them.

    About Haast’s Eagle, much more can be said of course. Did it eat babies? Probably, if it could get them. Tasty, nutritious, and does not put up much of a struggle, though there is no hard (i.e. Taung child-like) proof. Even adult humans would have been the correct *height*, though not shape. From taphonomy and induries on moa bones, Haast’s Eagle either ripped off a moa’s head – perfect for mired birds as per Pt I – or taloned into its pelvis.

    To appreciate this bird, one would have to see a talon with the keratin sheath in outline around it, and its metatarsals, and a tiger’s claw and a human hand to compare. (There is a photo of at least 2 of the 4 I think.)

    It could puncture moa pelves to the marrow, and that alone is often enough to kill any bird or mammal.

    As the remains under former roosing/nesting sites show, it hunted everything that it considered it worth hunting, as it pleased. (As in “That does a tiger taloned giant eagle do?”)

    About the Maori folk tales – these can be resolved. There are 2 sets of names connected with giant eale-like birds. One (poua, pouakai, …) refers to this bird, and apparently was later transferred to the Chathams swan by the Moriori.

    The other (hokioi, hakawai, …) refer indeed to _Coenocorypha_ spp., which happen to be among the smallest non-Passerines of NZ. They are simply VERY LOUD during their mating flights. In hindsight, it is pretty obvious if you read the tales word by word.

    Whatever walked into von Haast’s tent, it is unlikely to have been any diurnal raptor.

    The Douglas record – *tantalizing*. I have not seen the original. But the area used by a MVP would be too large for this being the only report I think. _Circus eylesi_ makes a better candidate for likely survival; from what I have seen it was also not a very prominent bird in Maori lore, as birds go.

  14. #14 HP
    January 28, 2008

    Darren, how about just a few decent Google search terms so I can find out more about giant, extinct, flightless owls on my own? Just a genus or two to get me past all the junk links out there.

    I tried googling “extinct owls,” and the only decent hits were for laughing owls, which were apparently normal-sized, flying-type owls.

  15. #15 Smilodon
    January 28, 2008

    In 2007 a White-tailed Eagle (Haliaeetus albicilla) was noted in the Hawaiian Islands (see North American Birds Vol. 61, no. 2, pp. 349-350). So two Haliaeetus species have been recorded recently from the Hawaiian Islands.

  16. #16 Eike
    January 28, 2008

    “And on Buteogallus and its paraphyly with respect to other buteonines, I deliberately avoided this because I knew it would involve a lengthy discussion of do Amaral et al. (2006: ref above). Sometimes I simply have to avoid discussing a specific area, otherwise I won’t get the job done.”

    In a nutshell: both Borras’ and Woodward’s “eagles” are more likely to have been eumelanin-heavy (grey/black) than phaeomelanin-heavy (ruddy, sandy, brown…). It is very, very likely that their tail bases were black, followed distally by a wide white band, followed by an equally black band, followed by a small white band at the tips. And if they had a dark/light belly pattern, it almost certainly was fine horizontal barring. On the other hand, they are very unlikely to have had a crest. Perhaps a hypotrophied tuft.

    Apart from that, do Amaral et al. (2006) didn’t include _B. aequinoctialis_, which (as they point out) makes any further taxonomic considerations significant to this article a moot point for the time being. One might as well look at the tail banding pattern and get as much phylogenetic signal from that as one can get without a mobio lab.

  17. #17 Eike
    January 28, 2008

    HP: try
    Ornimegalonyx
    “giant barn owl”
    giant tyto
    tyto caribbean
    (the last is not so good)

  18. #18 Steve Bodio
    January 28, 2008

    At last!

    I have handled some of the hawk eagles and would easily accept a merging of Hieiratus and Aquila. Spizaetus are quite different in aspect and tend to be more Accipiter- like; also often prominently crested theough that is probably a pretty plastic feature.

    Crowned eagles are scarier than tigers– you feel like prey when they look at you.

    Pigeons please!

  19. #19 Eike
    January 28, 2008

    “I have handled some of the hawk eagles and would easily accept a merging of Hieiratus and Aquila.”

    3 of _Hieraaetus_ s.l. – the not-so-small African, Ayre’s and New Guinean hawk-eagles – are distant and distinct enough to warrant generic separation (just because a situation is unresolved, wastebin taxa like an uber-_Aquila_ should not be created lightly I think). These don’t include the type species. Mess ensues. As per do Amaral et al:
    “We do not propose nomenclatural modifications,
    since only a complete buteonine analysis would permit
    such taxonomic changes.”

    I can only agree, except that sinking _Harpyhaliaetus_ (and _Amplibuteo_) in _Buteogallus_ is probably warranted. As per HBW, 3 of the 2 “_Leucopternis_” closer to _Buteogallus_/_Harpyhaliaetus_ than to anything else were once placed in the former genus. And as for the solitary eagles – they are very much light-colored inland black hawks on steroids. So nothing really unexpected here.

    Their data on “_Leucopternis” lacernulatus_ is worthy of a very serious discussion though, I’d guess. Including a certain aspect that is *not* mentioned in the study. Or not explicitly? Specimen LGEMA F39 is… interesting.

    (As opposed to a certain other recent DNA sequence study with profound taxonomic implications, they give their specimen numbers. Atta boys.)

  20. #20 Michael Richmond
    January 28, 2008

    To appreciate this bird, one would have to see a talon with the keratin sheath in outline around it, and its metatarsals, and a tiger’s claw and a human hand to compare. (There is a photo of at least 2 of the 4 I think.)

    There’s a photograph of a skeletal claw of Haast’s Eagle on Wikipedia — see this photograph. The length of the three phalanges of the middle claw is very nearly 10 cm, which by coincidence happens to be the same as the length of the three phalanges of my middle finger. Now, the eagle has that nasty extra claw at the end, which would have been covered in a larger sheath in life; still, it seems that a large human being — say, a professional basketball player — has hands roughly the size as the feet of a Haast’s Eagle.

    In other words, the eagle was perhaps the equivalent of Shaquille O’Neil wearing Freddy Krueger’s gloves. Actually, when I put it that way, it does sound pretty fearsome….

  21. #21 Bill Unzen
    January 29, 2008

    “(sometimes called the Woodward eagle: skeleton shown in adjacent pic)”

    The adjacent photo is actually the skeleton of a Merriam’s Teratorn (Teratornis merriami) at La Brea. It appears it was a mislabled pic from the photo essay on laist.com.

  22. #22 Jerzy
    January 29, 2008

    Oops… I meant white-tailed eagle. :(

    WHAT walked into Haast’s tent (except cute Maori girls, of course)?

  23. #23 Darren Naish
    January 29, 2008

    It appears it was a mislabled pic from the photo essay on laist.com.

    Dammit, I knew it. I’ll add a note. I figured that something wasn’t right because the bird shown above looks nothing like the complete Woodward eagle skeleton figured in Feduccia’s 1996 The Origin and Evolution of Birds.

  24. #24 Brian
    January 29, 2008

    This topic reminds me of the Steller’s sea eagles in Diergaarde Blijdorp, the zoo of Rotterdam. Those two birds are simply huge from a distance and highly intimidating at short range. By the way, a zookeeper told me how a colleague of his once fell while in their aviary and could only avoid being hurt by the eagles bursting down from their perches by some of his fellow zookeepers standing over him with brooms. Apparently, the birds consider creatures in vulnerable positions highly attractive, even if they are big mammals such as humans.
    I’d also like to mention that Errol Fuller’s ‘Extinct Birds’ mentions how Owen was told about that first moa bone he received, that it belonged to a giant eagle called ‘movie’. Perhaps this was another name used for Haast’s eagle by the Maori…or perhaps the harrier.

  25. #25 Lars Dietz
    January 29, 2008

    I didn’t know about the do Amaral et al. and Haring et al. papers. I’ve looked them up now, so thanks for pointing them out! I had no idea that buteonine phylogeny was such a mess, and a complete analysis of buteonines will obviously lead to a lot of renaming. Either several old generic names have to be resurrected and maybe even new ones created, or everything could be lumped into Buteo (probably a bad idea). However, I agree that before we have a complete analysis, a radical renaming wouldn’t make sense.

    I can’t wait for the giant pigeons, and the pyrotheres and astrapotheres!

  26. #26 Jerzy
    January 29, 2008

    Giant pigeons, giant owls, Grallistrix please…

    Actually, according to falconers, birds of prey are rather dumb and instinct-driven creatures. So a hungry Goshawk excited by sight of prey can attack it’s owner. So I suppose giant eagles attacked people with little regard to success.

  27. #27 sinuous_tanystropheus
    January 29, 2008

    Perhaps you should do an entry on Washington’s Eagle. Imagine, a cryptid raptor that John James Audubon himself painted, allegedly from a specimen.

    Image of the painting here.

    Interesting discussion of Washington’s Eagle here.

  28. #28 Mike
    January 29, 2008

    Atholl Anderson in a discussion of the original name for moa concluded the “Movie” was a corruption of the Maori name for the North Island, Te Ika a Maui, where the first specimen was collected.

    Anderson, Atholl J. 1987. The first-recorded name for moa. Journal of the Royal Society of New Zealand 17, no. 4: 421-422.

    By the way, the name for the giant New Zealand Harrier seems to be Circus teauteensis now, according to Tennyson and Martinson’s Extinct Birds of New Zealand (Te Papa Press, 2006). This is a lovely book of paintings, pretty scientifically up-to-date (in one case perhaps anticipating any actual peer-reviewed publication I’ve seen, but I’ll have to check that). So in some repects Worthy and Holdaway is no longer the best reference for NZ extinct birds.

    Here a painting of the Harrier from the museum’s collection, also used in the book:

  29. #29 Eike
    January 29, 2008

    Washington’s Eagle? The “cryptid” scenario requires special creation to work, essentially. It is about as impossible as it gets if one assumes that what Darwin and Wallace wrote has some basis in fact.

    The possibility that the single individual studied in detail was developmentally somewhat aberrant needs to be falsified before it can be discarded – and with n=1, that’s tough…

    Can Bald Eagles of our time be validly compared to the Bald Eagle of Audubon? Mengel’s 1953 paper for example was done when the northern BE population was right in the bottleneck; there is no way to tell if his measurements are representative of the population nearly 150 years earlier. And if greedier Bald Eagles are bigger Bald Eagles and also more “pesty” Bald Eagles (seems reasonable enough), odds are they are not.

    The most parsimonious scenario is still that _Falco washingtonii_ were juvenile or young mature Bald Eagles with (partially) delayed maturation, and that such large birds are not found today because a) wild-grown Northern Bald Eagles are simply not taken in hand (dead or alive) and measured anymore in such numbers and b) a scenario with at least *some* directional selection towards lower size would also need to be falsified first.

    Look at _Haliaeetus pelagicus niger_. Note the differences to this case. If in doubt, use a map.

    Has any progress been made on genotyping the Liverpool Dove?

  30. #30 Eike
    January 29, 2008

    “This is a lovely book of paintings”

    Indeed.

    “Atholl Anderson in a discussion of the original name for moa concluded the “Movie” was a corruption of the Maori name for the North Island, Te Ika a Maui, where the first specimen was collected.”

    Sounds good. Especially the “Norman-French” thing makes it look legitimate. 19th century anthropological writings of NZ are rich with crackpot beliefs trying to construct an alternate reality in which certain Polynesian peoples were some sort of noble savage version of the Lost Tribe of the Israelites.

    “‘A nalo i ke nalo a ke moa-nalo nalo.” ;-)

  31. #31 shiva
    January 29, 2008

    Thanks for the info on the harrier and the wing loading of Harpagornis. Sounds like it might have had a wing shape and flying style somewhat similar to a large Accipiter?

    (It’s kind of odd that the same species was referred first to Accipiter and then to Circus, as the former is among the proportionally shortest-winged, and the latter the proportionally longest-winged, of all raptors…)

    Haliaeetus pelagicus is IMO probably the most magnificent bird alive. I’ve seen a H. albicilla in flight, and that was breathtaking enough, but would absolutely love to see a pelagicus. Will probably never be able to afford to go to anywhere in its range, alas…

    With regard to Washington’s eagle, i think it is plausible that it might have been one of the last of a now-extinct species of Haliaeetus (especially with some of the stuff Audubon wrote about it being known as having different hunting and nesting habits from H. leucocephalus), but i wonder if anyone has considered the possibility of it being a leucocephalus x albicilla, leucocephalus x pelagicus, or even albicilla x pelagicus hybrid – perhaps with hybrid vigour to account for the size? In Audubon’s painting, the lighter bit on the wing is kind of reminiscent of a Steller’s wing markings…

  32. #32 Mike Habib
    January 29, 2008

    Ah, raptors, one of my favorite subjects!

    Thanks, Darren, for putting this together. Some scattered thoughts and ramblings:

    -One interesting note regarding Haast’s eagle is that it may have been able to afford a higher than average wing loading as a result of not needing to carry off prey. This would help to increase flight speed. Of course, just being big helps in that regard.

    -With regards to the giant island owls, Storrs Olson and I were discussing them a while back, and the claim that they were poor flyers or flightless is likely to be incorrect (though it is certainly suggested in the literature, so that’s not on Darren’s shoulders). Essentially, it seems that this idea came from noting the very small sterna of the giant owls. What was missed is that owls quite often have small sterna with low pectoralis fractions, while still maintaining strong flight ability. Some species have lower flight muscle fractions than albatrosses.

    Tyto ostologa can also be added to the giant tytonid owls list. It was about the size of a mid-range Bubo species (like a great horned owl), which isn’t shabby for a barn owl. The species was endemic to Haiti in the pleistocene.

    -With regards to the slender and long wings of Haliaeetus: a good observation, and a property that is, in part, simply a product of being large. Humeral strength scales with negative allometry in nearly all bird groups (there is one major exception; readers can ponder what it is). The negative allometry is not as strong in raptors as in other birds (i.e. large raptors are not as gracile as other large birds), but the trend is still there. Essentially, it seems that large birds get a gait-mediation advantage that reduces relative mechanical load.

    Jerzy: I also think it is sad that nobody has done biomechanical studies of how these eagles hunted their prey. I hope to fill in some of that work in the future. Perhaps I’ll bribe Darren into posting something on it if I get it published.

    Cheers,

    –Mike

  33. #33 Christopher Taylor
    January 30, 2008

    By the way, the name for the giant New Zealand Harrier seems to be Circus teauteensis now, according to Tennyson and Martinson’s Extinct Birds of New Zealand (Te Papa Press, 2006). This is a lovely book of paintings, pretty scientifically up-to-date (in one case perhaps anticipating any actual peer-reviewed publication I’ve seen, but I’ll have to check that). So in some repects Worthy and Holdaway is no longer the best reference for NZ extinct birds.

    Is this an update of Gill and Martinson’s New Zealand’s Extinct Birds of 1991?

    Circus teauteensis and C. hamiltoni both pre-date C. eylesi, but Worthy and Holdaway effectively dismissed both as nomina nuda. Both were named in exceedingly brief descriptions. There’s also the complicating possibility that there might have been more than one species of Circus in New Zealand.

  34. #34 sinuous_tanystropheus
    January 30, 2008

    Eike-

    The second link addresses a lot of the proposed known candidates for Washington’s Eagle, including Haliaeetus pelagicus niger. One of the main items that would seem to rule out Stellar’s and Bald Eagles is the black beak.

    Shiva-

    I guess hybridization could be a possibility. Does anyone know if eagle hybrids have been documented? Note that there are various reports of Washington’s Eagle outside those surrounding the collection of the specimen Audubon observed, from different time periods and geographic areas.

  35. #35 johannes
    January 30, 2008

    > I can find out more about giant, extinct, flightless owls on my own?

    The giant barn owls from Gargano were actually flying owls. This is quite frightening, especially if you remember that they lived roughly at the same time and place as *Oreopithecus*, so they might have considered a bipedal primate legitimate prey…

    This said, the Sophiornithidae from the Palaeogene of Europe are thought to be primitive owls, and some – if not all of them – were flightless and might have looked and behaved somewhat like primitive phorusrhacids. They were, however, not exactly gigantic (about the size of a chicken).

  36. #36 Christopher Taylor
    January 30, 2008

    Having now directly checked Worthy and Holdaway (2002) on what they said about the New Zealand extinct Circus:

    (1) Forbes (1892) coined the names Circus hamiltoni and C. teauteensis, probably for material from Te Aute in the North Island of New Zealand, but did not cite specific specimens and did not describe the distinguishing features of his species other than to say that they were both larger than the modern C. approximans.

    (2) Lambrecht (1933) treated both names as nomina nuda, but did mention a tibiotarsus in the British Museum collection from Te Aute. This specimen does have a label identifying it as a syntype of C. teauteensis.

    (3) Scarlett (1953) named C. eylesi for material from Pyramid Valley in the South Island.

    (4) Most authors have regarded C. hamiltoni as a nomen nudum, but have differed about C. teauteensis. Lambrecht (1933) and Oliver (1955) didn’t accept it as valid, Brodkorb (1964) did. Kinsky (1970) regarded C. teauteensis and C. eylesi as separate North and South Island species, respectively. Worthy and Holdaway (2002) used C. eylesi, but noted that restudy of Forbes’ material could change that.

  37. #37 Nick
    January 30, 2008

    Nitpicky Classics Guy sez…

    …Snowy owl Bubo scandiaca

    B. scandiacus. Nyctea is feminine, but Bubo is masculine. (Assuming, of course, that the intended etymology is Lat. bu^bo^ ‘horned owl’ and not bubo^ ‘I cry like a bittern’.)

    Congratulations on two great years! Now, when you discuss them, please be sure to tell us precisely where pyrotheres and astrapotheres come from (“mommy pyrotheres and astrapotheres” doesn’t count)!

  38. #38 David Marjanovi?
    January 30, 2008

    Nick, type the circumflex first and the letter afterwards, and you’ll get bb.

    Eike, did you find that somewhere, or did you just shift a ngaro i te ngaro a te moa across the ocean? (Polynesian linguistics must be exceedingly boring.)

  39. #39 Steve Bodio
    January 30, 2008

    Jerzy: “dumb and instinct driven” isn’t quite right (though it does sound a bit like Lorenz’s conclusion based on one zoo- damaged Imperial eagle he tried to train.)

    Accipiters in particular are given to reflexive, lightning- fast reactions that seem completely unreflective. But if they actually “attack” a trainer it is over food or dominance. Only captive raised birds, which seem to regard humans as conspecifics, do this; wild- caught birds or parent raised domestic, never or very rarely.

    Other large raptors, like eagles and falcons, seem intelligent and (especially large falcons) as playful as otters.

    They can still have these reflexive actions, like the zoo eagles mentioned above. I once saw a tame hunting (golden) eagle sitting peacefully in a friend’s yard, but when a pointer pup stumbled outside his pen he instantly hit the end of his leash.

    But then, I wouldn’t want to fall down in a zoo wolf pen either.

    BTW I have been a falconer for 45 years and have a Goshawk.

  40. #40 Eike
    January 30, 2008

    “It’s kind of odd that the same species was referred first to Accipiter and then to Circus, as the former is among the proportionally shortest-winged, and the latter the proportionally longest-winged, of all raptors…”

    _Circus dossenus_ anyone? Harriers are also excellent colonizers of oceanic islands (the best among smaller accipitrids IIRC), but once there there is a marked tendency to undergo wing length reduction. _Accipiter_ seems to have made little expansion beyond continental islands, leaving the bird-eating mid-sized diurnal raptor niche vacant in those places where such a lifestyl3 is really profitable. Unfortunately I don’t have any wing length data for _C. maillardi_ at hand.

    “did you find that somewhere, or did you just shift a ngaro i te ngaro a te moa across the ocean? (Polynesian linguistics must be exceedingly boring.)”

    Hi David! No, of course I shifted it.

    “Polynesian linguistics must be exceedingly boring.”

    Oh, I don’t think so at all. Simple rules and a rich oral history. Allows it to deduce names of prehistorically extinct birds in a few cases: on Tahiti, 2 parrots were distinguished, ‘a’a-taevao and ‘a’a-maha (“‘a’a” is the same word as “kaka”, only sound-shifted). “Maha” denotes abundance, “taevao” denotes a foreign origin.

    And then you have the report of Forster or some other early explorer, who mentions that the now-extinct _Cyanoramphus zealandicus_ was locally abundant and kept as a pet, but due to its lack of brilliant coloration, the locals imported red feathers of a psittacid from Samoa.

    Hybrid vigor to explain Washington’s Eagle? That would be interesting. I don’t know if such cases have been documented. For the observed nesting pair, incidentially (if the ID was correct) this would suggest a mixed pair – as per Haldane’s Rule, female bird hybrids are usually sterile, even in lineages where little postzygotic isolation exists such as in Anseriformes.

    (With _H. p. niger_ I did not imply anny connection to the Washington bird, but a comparison: it’s almost as mysterious, but what circumstantial evidence we have gives a consistent picture: restricted to a large peninsula, parapatric, sedentary habits, hypermelanism.)

  41. #41 Nick
    January 30, 2008

    Nick, type the circumflex first and the letter afterwards, and you’ll get b�b�.

    I tried typing them the way I normally do (Alt+0244 and Alt+0251) but they came out as scary question-mark things (like the ones you see above), so I figured the other way was safer.

  42. #42 Jerzy
    January 30, 2008

    @Steve Bodio
    How do falcons play?

  43. #43 David Marjanovi?
    January 30, 2008

    but they came out as scary question-mark things

    I was viewing the page in ISO-8859-1 while I wrote. Could that be it?

  44. #44 Mike Habib
    January 30, 2008

    Jerzy: I don’t have 45 years of falconry experience, but I do second Steve’s comments. I have about 15 years of experience with live raptors in a variety of contexts, and know a number of experienced falconers. While they may sometimes grumble about a stubborn bird, I have never heard one honestly suggest that raptors are unintelligent. They have a strong, reflexive feeding response (as do many mammalian hypercarnivores, especially cats). While large eagles may have attacked humans with a fairly low chance of success, this is not a sign of stupidity. The fact is that a) large eagles can take ridiculously large prey items, so there is chance of success (4 kg golden eagles dispatch 15 kg juv. pronghorns, for example) and b) the cost of failure is low. This second point is quite important. Because raptors can fly, the cost of a missed attempt at a larger, non-flying target is minimal (unless it is a strong, well-armed leaper like a good-sized cat, which I note are generally not on the menu). It’s a little expended effort, only. The risk of life and limb is greatly reduced relative to that of a terrestrial predator attempting the same feat.

    Flight makes a tremendous difference.

    Cheers,

    –Mike

  45. #45 renz
    January 31, 2008

    ‘To my knowledge, no-one has documented a human death caused by a Harpy; an African crowned, however, has killed an 8-yr old child.’

    It’s nothing new coz’ these raptors are also opportunistic hunters they will take anything that is available and vulnerable. Even the Philippine eagle has similar reports taking a subanon baby from the back of his mother. As my father used to tell me when they were still kids, they were not allowed to play outside the field alone in Luzon coz a ‘Balawe’(local name for the eagle) might seize them and take them up in the air. Though it’s undocumented but things like this in those days (early 1930′s) probably hard to documents or the lease of their concern.

    Probably because small children looks like the shape and size of monkeys which the eagles favorite prey.

  46. #46 Nick
    January 31, 2008
    but they came out as scary question-mark things

    I was viewing the page in ISO-8859-1 while I wrote. Could that be it?

    Nope, that’s what I’m using, too. :-(

    Maybe it’s a Firefox thing. Anyway, we’re well beyond the topic at hand…

  47. #47 Jerzy
    January 31, 2008

    I see… sorry for that. Raptors are certainly among my favorites.

    So how exactly they play? Grab something?

  48. #48 Mike Habib
    February 1, 2008

    Excellent question, Jerzy. I have seen falcons perform complicated acrobatics when not hunting, and also have witnessed captive individuals pounce on pre-killed food in a manner that seems roughly analogous to a domestic cat playing with a toy. Falcons are also known to pull some pretty fantastic tricks when flying on a falconer’s lure. While this obviously directly links to hunting behavior, it could be seen as similar to the “play” exhibited by domestic predators (dogs and cats) which essentially hunt their toys. Anyone else have more examples or something specific?

  49. #49 renz
    February 1, 2008

    I have one good example that links to hunting behavior,
    Mock attack of a juv Philippine eagle.

    R. S. Kennedy
    (1981c) claimed to have discovered why the species has such long legs, and how it manages to exploit such strictly nocturnal mammals as flying lemurs;
    When he observed a young bird fly to a knot-hole in a tree, grasp the rim with its feet, propping on its tail and embracing the trunk with its wings, poke its head briefly into the cavity and then one long leg, only to pull out a toy? in the form of a piece of rotten wood, which it proceeded to dismember.

    Source: Threatened Birds of Asia. (Ecology page 14)

  50. #50 Steve Bodio
    February 6, 2008

    Jerzy: sorry to be so long getting back. They play as Mike says. Also, many, including my current gos, will play with objects like balls or their lures, mock- attacking them or picking them up, flying to a perch, dropping them, and repeating the sequence.

    When we raise young birds we leave dog and cat toys with them, and they will toss them around for hours, or pounce and make them squeak. They do not consider them food or try to eat them.

    I should add that until they are fledged they live in a plastic child’s wading pool on a low table in the house, where they can socialize and bond with humans and dogs.

  51. #51 muhabbet
    March 25, 2009

    thanks..

    [from Darren: hey there! Thanks for your message! I deleted the url because you're a spammer aren't you! And you're banned! Thanks!]

  52. #52 Hanneke
    November 4, 2009

    Hi Darren,

    Just some notes on the Gargano avifauna and inferred predator-prey relationships. Birds of prey dominated the Gargano avifauna and filled the niche of predator left empty in the absence of carnivores (Ballman, 1973; 1976). The raptors vary greatly in size, with the largest species Garganoaetus found in the youngest deposits also containing the largest rodents. The most remarkable feature of the cervoid Hoplitomeryx, the presence of five horns, are interpreted as a defence against birds of prey by Leinders (1984).

  53. #53 David Marjanović
    November 4, 2009

    hey there! Thanks for your message! I deleted the url because you’re a spammer aren’t you! And you’re banned! Thanks!

    There is no “you” there. This is a spambot – a program that crawls through the tubes of the Internets and automatically generates blog comments.

    [from Darren: amusingly, this message was filtered out as spam!]

  54. #54 gray Stanback
    January 3, 2010

    In the Ver 1 post you mentioned that a subfossil sea eagle had been found in New Zealand. Well, it could have been a white-bellied sea eagle, because those live in Australia-are there any reports of them in New Zealand?

  55. #55 Christopher Taylor
    January 4, 2010

    Nope, the New Zealand specimen wasn’t a white-bellied sea eagle – it was a bald eagle that was presumably the victim of a mistaken label, and has therefore been struck off the New Zealand record (see Worthy & Holdaway, 2002, for a review).

    Has the white-bellied sea eagle ever made it to New Zealand? There are a few tantalising old records that suggest the possibility of vagrants (reviewed in Oliver’s Birds of New Zealand, if I recall correctly) but nothing on which you could hang your hat.

  56. #56 Dartian
    January 5, 2010

    gray Stanback:

    In the Ver 1 post you mentioned that a subfossil sea eagle had been found in New Zealand

    That would be the extinct Chatham Island sea eagle Haliaeetus australis*, which is generally regarded as a distinct species. According to Olson (1984) it was not, contrary to what its distribution would suggest, most closely related to the Australasian white-bellied sea eagle H. leucogaster, nor to the other extant sea eagle with a South Pacific distribution, the Solomon Islands sea eagle H. sanfordi. Rather, judging by skeletal morphology, the closest extant relatives of H. australis are two Northern Hemisphere species: the white-tailed sea eagle H. albicilla and, particularly, Steller’s sea eagle H. pelagicus.

    * AFAIK, its subfossils are only known from the Chatham Islands, which are located rather far to the east of New Zealand’s main islands.

    Reference:

    Olson, S.L. 1984. The relationships of the extinct Chatham Island eagle. Notornis 31, 273-277.

  57. #57 gray Stanback
    January 5, 2010

    Christopher Taylor, can you give me a direct link to a site that cover those vagrants?

  58. #58 Christopher Taylor
    January 5, 2010

    Nope, I can’t. This is one of those cases where not everything is available on the internet.

    Oliver, W. R. B. 1955. New Zealand Birds (revised ed.) Reed: Wellington.

    For the so-called “Chatham Island sea eagle” (despite Dartian’s comment, almost certainly no such thing):

    Worthy, T. H., & R. N. Holdaway. 2001. The Lost World of the Moa: Prehistoric life of New Zealand. Indiana University Press: Bloomington (Indiana).

  59. #59 Dartian
    January 7, 2010

    Christopher: The Chatham Island sea eagle is not a valid species? Oops. Sorry for disseminating false information, gray Stanback. In my defence, though, I’ll say that I did take a look at the Ornithological Society of New Zealand checklist of New Zealand birds before posting my previous comment, and that list still includes Haliaeetus australis as a valid (if extinct) taxon.

    I don’t have access to Worthy & Holdaway (2001); what do they say about the supposed CI sea eagle?

  60. #60 Christopher Taylor
    January 7, 2010

    Worthy & Holdaway 2002, sorry, not 2001. But to sum up: Haliaeetus australis was described from a specimen collected by Forbes. If I understood Worthy & Holdaway’s comments correctly, Forbes probably didn’t directly label the specimen itself as from the Chathams, but it had been put among Chathams material. Millener later commented (in 1996 or 1999) that the H. australis specimen was indistinguishable from H. leucocephalus (the bald eagle), but didn’t actually regard it as an invalid species (presumably because he didn’t expect that there were bald eagles in New Zealand). According to Worthy & Holdaway, no further sea eagle specimens have been found from the Chathams, despite a collection of subfossil bird bones numbering in the thousands. Forbes apparently also conducted some excavations in north-east North America, so it seems likely that the ‘H. australis‘ specimen was collected there and later mixed up with the Chathams collection.

  61. #61 Christopher Taylor
    January 7, 2010

    Just looking at that OSNZ list, too, I see that the base list was published in 1990. There’s a few other subsequent revisions that aren’t included – no mention of Apteryx rowi, for instance.

  62. #62 gray Stanback
    January 18, 2010

    I just found out that the Te Papa Museum of New Zealand does have in its enormous bird collection a White Bellied Sea-Eagle that was apparently collected in New Zealand itself. Would that be the only confirmable record of a Haliaeetus in New Zealand, not counting the dubious Chatham fossils?

  63. #63 Dartian
    January 20, 2010

    gray Stanback:

    a White Bellied Sea-Eagle that was apparently collected in New Zealand itself

    Interesting. Do you have any idea when it was supposedly collected? I had a look in Falla et al. (1987), where I found this slightly cryptic statement (p. 90):

    The common Australian Sea Eagle (Haliaeetus leucogaster) might be expected to wander to these islands [i.e., New Zealand], but the evidence that it has done so on a number of occasions is inconclusive.

    So apparently, there does seem to have been some supposed sightings of this species in NZ, but none of them have been officially accepted. Or that, at least, was the case in the late 1980ies.

    Reference:

    Falla, R.A., Sibson, R.B. & Turbott, E.G. 1987. Collins Guide to the Birds of New Zealand. Revised ed. Collins, Auckland and London.

  64. #64 Alex
    January 21, 2010

    This is such great stuff! I wish you’d written more about the living island giant: the Philippine Eagle. I’ve read elsewhere that the Philippine Eagle evolved from a much smaller ancestor (snake eagle?). My question is this: has anyone looked into the possibility that the Philippine Eagle attained its size and power in order to hunt the small deer of some of the islands? (Perhaps the deer haven’t been on the islands as long as the eagle, but I’m curious nonetheless.)

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