Pack hunting dinosaurs

[Dinoguy2]

Lastly, some here have asked whether ants are pack hunters. Yes, they are,

This is the problem, the definition of pack hunting. If you define it so broadly as it includes the behavior of ants, then basically everything living is a pack hunter and the term becomes meaningless.

Correct me if I'm wrong, but from the looks of it, you didn't read the definition of "pack-hunting" or the explanation of how ants & vertebrates differ, both of which were included in my previous post. For future reference, I've included both below, the former in the Orellana/Rojas quote & the latter in the 1st Stevens quote. & again, you don't have to hunt in a pack all the time to be a pack hunter (See the 2nd Stevens quote). Even wolves don't hunt in packs all the time ("In summer, when wolves hunt singly or in small groups, caching appears to be an important behavior...that helps secure excess food left from large prey or reduce loss to scavengers and maggots": http://www.amazon.com/Wolves-Behavior-Conservation-David-Mech/dp/0226516970/ref=sr_1_1?s=books&ie=UTF8&qid=1375750380&sr=1-1 ).

Quoting Orellana/Rojas  (See the 1st 2 pages: http://www.ibiologia.unam.mx/links/neo/revista/Volumenes%2016-17/16-2/ON%20(16)%20271-276.pdf ):

Cooper- ative hunting, in contrast, is characterized by a clear division of labor which enhances success of prey capture; prey are shared according to some social order (e.g., dominance, hierarchy)...and coordinating signals may be used (Bed- narz 1988a, Ellis et al. 1993, Coulson & Coul- son 1995). Cooperative hunting is executed by pairs, family groups, or sibling groups, and is generally related to cooperative breeding (Bednarz 1988a, 1988b). Because of the diffi- culty of obtaining quantitative data on free- ranging birds, the occurrence of social forag- ing in diurnal raptors could be underesti- mated (Ellis et al. 1993).

Quoting Stevens ( http://www.nytimes.com/1993/01/19/science/rabbits-beware-some-birds-of-prey-hunt-in-packs.html?pagewanted=all&src=pm ):

On the other hand, raptor teamwork appears to signify a higher order of behavior than the cooperative hunting of spiders and ants, in whom it is genetically preprogrammed.

Dr. Ellis has spent months observing the behavior of golden eagles, and he says, "It's hard for me to imagine that they hadn't learned from their mistakes early on and were profiting from that learning, which means they're intelligent rather than practicing something innate." All of this, he says, is grist for further investigation -- a daunting task, given the difficulty of studying raptors.

Quoting Stevens ( http://www.nytimes.com/1993/01/19/science/rabbits-beware-some-birds-of-prey-hunt-in-packs.html?pagewanted=all&src=pm ):

Raptors may use coordinated tactics only when solitary hunting does not provide enough food or is too difficult. Harris's hawks, for instance, use them only in winter, when a shortage of smaller quarry like small birds forces them to go after bigger game like jack rabbits, which are several times the size of a hawk.

Dr. Ellis and his colleagues speculate that when raptors hunt alone, they will not even try to capture prey that they know can be captured only through teamwork; it is not worth the expenditure of energy. But bigger game or the quicker capture resulting from group efforts can make the expenditure worthwhile.

Sorry, I'm not seeing where the scientist referred to "packs" anywhere in those sources. The journalist used the word pack (and journalists are known for their utter lack of scientific knowledge), but the quotes from the scientist use the term cooperative hunting. I did a ctl+f on the scientific paper you linked and the word pack is not used once. And I was originally talking about ants, your linked sources are talking about hawks. While it's still a huge linguistic stretch, I could see hawks, which do occasionally form small social groups with some form of rough hierarchy, maybe described as packs without laughing. Not so for invertebrates.

I would have no problem speculating that dromaeosaurs were social foragers based on the current circumstantial evidence (but just speculating, not saying it's probable to be true). Packs? Not so much.

[HD-man]

Sorry, I'm not seeing where the scientist referred to "packs" anywhere in those sources.

To quote Stevens, "Wolves also use both the relay tactic, running the quarry around in a circle, and the flush-and-ambush ploy. And their social structure is almost identical to that of Harris's hawk, leading Dr. Bednarz, who has studied both species, to refer to Harris's hawk families as packs" ( http://www.nytimes.com/1993/01/19/science/rabbits-beware-some-birds-of-prey-hunt-in-packs.html?pagewanted=all&src=pm ).

The journalist used the word pack (and journalists are known for their utter lack of scientific knowledge), but the quotes from the scientist use the term cooperative hunting. I did a ctl+f on the scientific paper you linked and the word pack is not used once.

1stly, way to stereotype all journalists. Yes, some are like that, but others aren't. Specifically, the Science Times is well-known for its high-quality writing. Science & outdoor educators seem to recognize this ( http://www.acornnaturalists.com/store/NEW-YORK-TIMES-BOOK-OF-BIRDS-THE--P2428C8214.aspx ).

2ndly, among other things, "pack-hunting" is a more informal term for true cooperative hunting. That's why you don't usually see deinonychosaurs or dromaeosaurids referred to as "raptors" in scientific papers. It's not that hard to understand.

And I was originally talking about ants, your linked sources are talking about hawks.

As I've already shown in my 1st 2 posts, the ants issue was covered in both the 1st page of Ellis et al. 1993 & the Stevens article. Again, it's not that hard to understand. However, just to make sure it's clear, see the Gardom/Milner quote.

Packs? Not so much.

Only if you ignore all the evidence discussed under "5thly" in my 1st post AWA our understanding of living pack animals.

Quoting Gardom/Milner ( http://www.amazon.com/Natural-History-Museum-Book-Dinosaurs/dp/184442183X/ref=sr_1_1?s=books&ie=UTF8&qid=1375901817&sr=1-1 ):

A surging army of soldier ants will make a concerted attack on a wasps' nest and destroy it with great efficiency. This is certainly co-operative, although the level of interaction it requires is pretty low. At a more complex level, pelicans fish together, and lions have complex techniques of encircling and stalking that may include several individuals operating as a highly organized team.

[Dinoguy2]

"2ndly, among other things, "pack-hunting" is a more informal term for true cooperative hunting."
This directly contradicts what Stevens said (sorry, must have missed that quote earlier).

"And their social structure is almost identical to that of Harris's hawk, leading Dr. Bednarz, who has studied both species, to refer to Harris's hawk families as packs""

So pack refers to the social structure, it's not an informal term for a hunting style unless the cooperative hunting is being used by animals that live in packs.

And as long as we're speculating wildly with no evidence about prehistoric animals, I'll point out that dromaeosaurs are probably far, far less intelligent than hawks or wolves, based on brain/body ratio (which only goes so far, but it's the best we'll ever do for Mesozoic species). Though if you define what ants do as pack hunting, then every social organism lives in packs, and every social carnivore is a pack hunter.

According to the same quote, pelicans are "complex" pack hunters. Do you agree with that? Why is nobody going on and on about how, based on that, Pteranodon probably were too? Pack hunting pteorsaurs!

[HD-man]

Wow, are you really not getting it or just trying to annoy me? In any case, I'll assume the former & try to spell everything out for you.

So pack refers to the social structure, it's not an informal term for a hunting style unless the cooperative hunting is being used by animals that live in packs.

This is where the "among other things" part of my previous post comes in. Most scientists use "packs" as a more informal term for groups of true cooperative predators, regardless of species or social structure. Some use it as a term for either 1) groups of true cooperative canids, or 2) groups of 3 or more true cooperative predators, or 3) groups of 3 or more true cooperative canids. Others use it as a term for family groups of predators, regardless of whether they hunt in a true cooperative manner.

And as long as we're speculating wildly with no evidence about prehistoric animals,

What's this "we're" stuff? Right now, you're the only 1 "speculating wildly with no evidence".

I'll point out that dromaeosaurs are probably far, far less intelligent than hawks or wolves, based on brain/body ratio (which only goes so far, but it's the best we'll ever do for Mesozoic species).

You don't have to be as intelligent as a hawk or wolf to be a pack hunter. As you may remember (If not, see the Tudge quote in my 1st post), ground hornbills are pack hunters. Based on what I've read, dromaeosaurids ( http://blog.hmns.org/2012/06/bakker-blogs-the-kleptomania-continues-with-a-sid-vicious-julieraptor-dino-rustlers-part-ii/ ) & ground hornbills ( http://books.google.com/books?id=EnVJYgfwjt4C&pg=PA273&dq=%22ground+crew+the+largest%22&hl=en&sa=X&ei=z1gEUuvaLbai4AO3roGwBg&ved=0CC0Q6AEwAA#v=onepage&q=%22ground%20crew%20the%20largest%22&f=false ) were/are similarly intelligent to wild turkeys (which, if they're anything like domestic chickens, "fall about mid- range on the intelligence scale of birds": http://www.amazon.com/Raising-Chickens-Dummies-Kimberley-Willis/dp/0470465441/ref=sr_1_1?s=books&ie=UTF8&qid=1376016897&sr=1-1 ).

Though if you define what ants do as pack hunting, then every social organism lives in packs, and every social carnivore is a pack hunter.

Let's see if I can make it anymore clear than I already have in all my previous posts.

1stly, that's the most ridiculous thing I've heard so far, especially given that Ellis et al. listed all non-bird animals known to be true cooperative (I.e. Pack) hunters by their definition on the 1st page of their 1993 paper (To quote Ellis et al., "True cooperative hunting...is well known for some species of carnivorous mammals...for some communal spiders...for army ants...and driver ants"). You would've known that had you actually bothered to look at the sources I provided, especially those in my 1st post (E.g. Ellis et al. 1993).

2ndly, while ants are technically pack hunters by definition, their pack-hunting is different from that of vertebrates in that it's innate (as opposed to learned), & is thus considered a lower order/less complex level of behavior than that of social foraging vertebrates (pack-hunting or otherwise). If you want, you can do what I do & refer to true cooperative invertebrates as "swarm hunters" (in reference to  their "swarm intelligence"). As for pelicans, they hunt in a pseudo-cooperative manner (To quote Ellis et al., "Piscivorous birds often hunt communally but do not share prey").

Why is nobody going on and on about how, based on that, Pteranodon probably were too? Pack hunting pteorsaurs!

Now that you mention it, Bakker has speculated that, like pelicans, Pteranodon hunted in a pseudo-cooperative manner.

[Gwangi]

I'm a little confused as to why this tread has been resurrected but for some reason I feel compelled to contribute.

HD-man, you can define pack hunting however you want. Hornbills and pelicans are pack hunters? Fine! Perhaps dromaeosaurs also foraged together for small game, I don't recall anyone arguing against that sort of concept. Some people in this thread are getting too hung up on the definition of a word and missing the point all together. The evidence certainly suggests that dromaeosaurs were at least social. I'm on board with that. What the evidence does not show is that dromaeosaurs lived in a sophisticated social hierarchy dominated by an alpha pair and capable of taking game much larger than themselves. That is what wolves do and that is what I've always thought of as a pack lifestyle or pack hunting. Wrong or not about the definition of a true pack I still stand by my original claim.
The popular media depicts these animals like wolves (not like ground hornbills). "Jurassic Park", "Raptor Red", "Dinosaur Planet", "Jurassic Fight Club", "When Dinosaurs Roamed America", "Clash of the Dinosaurs", and all sorts of movies and documentaries and even popular scientists like Bakker all describe dromaeosaur lifestyle as though they were more similar to canines and lions than hornbills or hawks.

I see scenes like this...


Far less likely than scenes like this...


And behavior like this...
http://www.youtube.com/watch?v=nAiGq_7f_uU

Is far more likely for a dromaeosaur than behavior like this...
http://www.youtube.com/watch?v=CT_3QiWQh8M

[HD-man]

I'm a little confused as to why this tread has been resurrected but for some reason I feel compelled to contribute.

As pointed out in my 1st post, there were many misleading or false claims being made in this thread, so I thought I'd correct them.

HD-man, you can define pack hunting however you want. Hornbills and pelicans are pack hunters? Fine!

1stly, it's not a matter of how I define it, but how field biologists who have studied social foraging in a wide range of animals define it (E.g. See "1stly" in my 1st post).

2ndly, I never said that pelicans are pack hunters, but that (as pointed out on the 1st page of Ellis et al. 1993) they hunt in a pseudo-cooperative manner.

Perhaps dromaeosaurs also foraged together for small game, I don't recall anyone arguing against that sort of concept...What the evidence does not show is that dromaeosaurs lived in a sophisticated social hierarchy dominated by an alpha pair and capable of taking game much larger than themselves.

Out of curiosity, how do you define "small" & "large" in this context? I ask b/c 1) some ppl I've talked to consider Protoceratops & sub-adult Tenontosaurus to be small (despite being larger than their respective dromaeosaurid predators), & 2) as Maxwell & Ostrom have shown (See their 1995 paper for the technical version & this article for the popular version: http://www.naturalhistorymag.com/htmlsite/master.html?http://www.naturalhistorymag.com/htmlsite/1299/1299_feature.html ), juvenile/sub-adult Tenontosaurus were the preferred prey of lone/pack-hunting Deinonychus, respectively.

Wrong or not about the definition of a true pack I still stand by my original claim.

Correct me if I'm wrong, but didn't you say in 1 of your previous posts that your original claim was based on Roach & Brinkman 2007 (which, as pointed out under "4thly" in my 1st post, made many a misleading or false claim)?

The popular media depicts these animals like wolves (not like ground hornbills). "Jurassic Park", "Raptor Red", "Dinosaur Planet", "Jurassic Fight Club", "When Dinosaurs Roamed America", "Clash of the Dinosaurs", and all sorts of movies and documentaries and even popular scientists like Bakker all describe dromaeosaur lifestyle as though they were more similar to canines and lions than hornbills or hawks.

1stly, no offense, but have you actually read "Raptor Red"? I ask b/c it's made pretty clear throughout the book that the behavior of Bakker's dromaeosaurid characters was mainly based on that of diurnal raptors (especially in the Epilogue). Wolves & lions were only mentioned 4 times & once, respectively, & in a context having little-to-nothing to do w/pack-hunting (E.g. "A lone raptor is like a lone wolf — a meat-eater who must be able to forage for small fry"). This is made even more clear in his children's books (E.g. "Tree-climbing cannibals who fed their babies the way eagles feed their chicks": http://www.mychildsbookshelf.com/Raptor-Pack-Step-into-Reading-Step-5_p_537.html ).

2ndly, to be fair, bird packs are comparable to wolf packs in terms of social structure & hunting tactics (E.g. See the Tudge quote for ground hornbills & this article for diurnal raptors: http://www.nytimes.com/1993/01/19/science/rabbits-beware-some-birds-of-prey-hunt-in-packs.html?pagewanted=all&src=pm ).

Quoting Tudge ( http://www.amazon.com/Bird-Natural-History-Birds-Where/dp/B007K4GP1W/ref=la_B000APQE3M_1_2?ie=UTF8&qid=1354947277&sr=1-2 ):

The sociality that is encouraged by the diet tends to spill over into all aspects of life. So it is that hornbills are fruit eaters and also, as we will see in Chapter 7, are outstandingly social breeders, with various kinds of social arrangements. But also among hornbills we see an interesting twist—where the innate sociality has in turn become adapted to a quite different kind of feeding. For among the biggest of all hornbills, and in various ways distinct from the rest, are the two species of ground-hornbills from Africa. Ground-hornbills are not mere fruit eaters: they are formidable predators. The beak is like an icepick. They can hack their way into a tortoise. The Northern species is among the biggest of all avian predators. The ancestors of ground-hornbills were presumably fruit eaters, and that, perhaps, is how they first evolved their sociality. Now, as predators, they hunt in packs. Typically they chase some hapless creature like a hare into a bush and then some act as beaters while others lie in wait and deliver the coup de grace. The packs are usually family groups. They can be seen as strategic predators like wolves or perhaps as problem families, terrorizing the neighborhood.

[Gwangi]

As pointed out in my 1st post, there were many misleading or false claims being made in this thread, so I thought I'd correct them.

Must have missed that one. I wonder if you feel it was ultimately worth it.

1stly, it's not a matter of how I define it, but how field biologists who have studied social foraging in a wide range of animals define it (E.g. See "1stly" in my 1st post).

Well I'm not a field biologist. To me the word "pack" has certain implications that I don't feel apply to some of these animals that are alleged pack hunters.

Out of curiosity, how do you define "small" & "large" in this context? I ask b/c 1) some ppl I've talked to consider Protoceratops & sub-adult Tenontosaurus to be small (despite being larger than their respective dromaeosaurid predators), & 2) as Maxwell & Ostrom have shown (See their 1995 paper for the technical version & this article for the popular version: http://www.naturalhistorymag.com/htmlsite/master.html?http://www.naturalhistorymag.com/htmlsite/1299/1299_feature.html ), juvenile/sub-adult Tenontosaurus were the preferred prey of lone/pack-hunting Deinonychus, respectively.

I suppose I would consider small game anything that is smaller than the animal hunting it or perhaps any animal small enough to be killed by a single individual of its species. Large would be a 20' or longer Tenontosaurus weighing over a ton being killed by a 160 lb Deinonychus comparable in size to a human.

Correct me if I'm wrong, but didn't you say in 1 of your previous posts that your original claim was based on Roach & Brinkman 2007 (which, as pointed out under "4thly" in my 1st post, made many a misleading or false claim)?

You're resurrecting a thread over a year old. I don't know what I said on this forum a year ago. I recall the paper however and using it as a source but it is not the only reason I've come to my conclusion. Even if the paper is bogus, I still doubt the claims or pack hunting in dromaeosaurs. That is to say, pack hunting like wolves or lions...not like ground hornbills which to the best of my knowledge don't cooperate to take prey significantly larger than themselves. Is there is another praise or term I can use to distinguish between these two hunting methods so I don't have to clarify my meaning in every post?

1stly, no offense, but have you actually read "Raptor Red"? I ask b/c it's made pretty clear throughout the book that the behavior of Bakker's dromaeosaurid characters was mainly based on that of diurnal raptors (especially in the Epilogue). Wolves & lions were only mentioned 4 times & once, respectively, & in a context having little-to-nothing to do w/pack-hunting (E.g. "A lone raptor is like a lone wolf — a meat-eater who must be able to forage for small fry"). This is made even more clear in his children's books (E.g. "Tree-climbing cannibals who fed their babies the way eagles feed their chicks": http://www.mychildsbookshelf.com/Raptor-Pack-Step-into-Reading-Step-5_p_537.html ).

I read "Raptor Red" shortly after it came out in the summer between 7th and 8th grade. Forgive me if I don't recall all of the details but I recall the "raptors" attempting to kill prey animals of considerable size in a way that has been perpetrated by the media. Having seen some of Bakker on popular television programs I believe his interpretation of dromaeosaur lifestyle is pretty liberal.

2ndly, to be fair, bird packs are comparable to wolf packs in terms of social structure & hunting tactics (E.g. See the Tudge quote for ground hornbills & this article for diurnal raptors: http://www.nytimes.com/1993/01/19/science/rabbits-beware-some-birds-of-prey-hunt-in-packs.html?pagewanted=all&src=pm ).

That's all well and good but we're talking about dromaeosaurs here. I'm aware and have grown more aware in the past year of cooperative hunting in predatory birds. I know it exists, if it didn't then forget about the sport of falconry. But dromaeosaurs don't match up to modern raptors in terms of intelligence as far as we can tell. So the question then becomes; were these dinosaurs smart enough to hunt in packs? I'm not saying they were dumb but most of the estimates I see compare the intelligence of a Troodon to an opposum. Eagles, hawks and falcons are all pretty smart birds. So while it is refreshing to see someone compare an extinct dinosaur to a living dinosaur instead of a canine the issue of brain size is something to take into consideration. There is evidence that dromaeosaurs traveled together and fed together but none that I'm aware of that they hunted and killed large game together.

[HD-man]

You're resurrecting a thread over a year old. I don't know what I said on this forum a year ago.

Sorry, I forgot. Also, sorry if I came off as at all antagonistic in my previous post. I'm usually not like that, but then ppl like Dinoguy2 seemingly try to annoy me & I sometimes get moody as a result.

That is to say, pack hunting like wolves or lions...not like ground hornbills which to the best of my knowledge don't cooperate to take prey significantly larger than themselves.

AFAIK, ground hornbill packs take prey as large as hares, tortoises, & snakes. The way they take large & dangerous snakes is especially interesting (See the Farlow quote).

Is there is another praise or term I can use to distinguish between these two hunting methods so I don't have to clarify my meaning in every post?

I'll get back to you about that when I think of something.

I read "Raptor Red" shortly after it came out in the summer between 7th and 8th grade. Forgive me if I don't recall all of the details but I recall the "raptors" attempting to kill prey animals of considerable size in a way that has been perpetrated by the media.

I don't remember how the media perpetrated pack-hunting dromaeosaurids at the time, but having the book on-hand I know that Bakker's Utahraptor characters killed large prey in pretty much the same way as that described in the literature ("Rather, numerous although superficial wounds inflicted over various parts of the body could have greatly weakened the prey through blood loss before it was killed, a technique used by modern pack-hunting canids and hyenids: http://www.amazon.com/Carnivorous-Dinosaurs-Life-Past/dp/0253345391/ref=sr_1_3?s=books&ie=UTF8&qid=1376091484&sr=1-3 ).

So the question then becomes; were these dinosaurs smart enough to hunt in packs?

Based on what I've read, yes (See "3rdly" in my 1st post for the short answer; Read on for the long 1): Dromaeosaurids ( http://blog.hmns.org/2012/06/bakker-blogs-the-kleptomania-continues-with-a-sid-vicious-julieraptor-dino-rustlers-part-ii/ ) & ground hornbills ( http://books.google.com/books?id=EnVJYgfwjt4C&pg=PA273&dq=%22ground+crew+the+largest%22&hl=en&sa=X&ei=z1gEUuvaLbai4AO3roGwBg&ved=0CC0Q6AEwAA#v=onepage&q=%22ground%20crew%20the%20largest%22&f=false ) were/are similarly intelligent to wild turkeys (which, if they're anything like domestic chickens, "fall about mid- range on the intelligence scale of birds": http://www.amazon.com/Raising-Chickens-Dummies-Kimberley-Willis/dp/0470465441/ref=sr_1_1?s=books&ie=UTF8&qid=1376016897&sr=1-1 ); This makes sense, given that 1) Archaeopteryx were probably as intelligent as domestic chickens (See the Burish et al. quote), & 2) non-avian maniraptorans were probably either as intelligent as or more intelligent than Archaeopteryx (See the Walsh quote; I'm thinking the latter, given Bakker's emphasis on the difference btwn wild & domestic fowl, intelligence-wise).

but most of the estimates I see compare the intelligence of a Troodon to an opposum.

Actually, "some learning and discrimination tests rank opossums above dogs and more or less on a par with pigs in intelligence" ( http://www.amazon.com/Wild-Mammals-North-America-Conservation/dp/0801874165/ref=sr_1_2?s=books&ie=UTF8&qid=1376090062&sr=1-2 ). In any case, the estimates you're referring to were based on brain:body ratios (as opposed to cerebrum:brain ratios). & yes, there is a big difference btwn said ratios (E.g. "Although the relative brain size of T. rex is nearly twice that of the equivalently-sized Carcharodontosaurus, there is no appreciable difference in cerebrum-brain ratios": http://ca.linkedin.com/pub/gr-hurlburt/39/354/7b ).

So while it is refreshing to see someone compare an extinct dinosaur to a living dinosaur instead of a canine

To answer your 1st question ("I wonder if you feel it was ultimately worth it"), I wonder too sometimes. In this case, it was worth it b/c at least 1 person showed some appreciation for what I was doing.

There is evidence that dromaeosaurs traveled together and fed together but none that I'm aware of that they hunted and killed large game together.

Actually, there may be trackway evidence of dromaeosaurids pack-hunting an ornithomimid (See "Figure 1.5", page 8: http://assets.cambridge.org/97805218/89964/excerpt/9780521889964_excerpt.pdf ). However, the other dromaeosaurid trackways are even more suggestive IMO. Specifically, I'm referring to the Dromaeopodus trackways in which "it is clear that the animals were not hunting at the time" ( http://www.wired.com/wiredscience/2007/10/at-long-last-dromeosaur-tracks/ ); To quote Bakker, "Predators don't usually hang out in groups if they don't hunt together. Tigers are like this — they mostly hunt alone, and you don't see bunches of tigers lying around together. But lions are social predators. They hunt and raise their young and sleep and snore together" ( http://www.amazon.com/Raptor-Pack-Step-into-Reading-Step-5/dp/0375823034/ref=la_B000AP7OMC_1_2?ie=UTF8&qid=1338527221&sr=1-2 ).

Quoting Farlow ( http://www.jstor.org/stable/10.2307/2424244 ):

The ground- hornbill, Bucorvus leadbeateri, a snake predator, hunts in groups that "work in concert by surrounding the snake and, whilst shielding their bodies with their wings, steadily advance on their victim until they are within close enough range to kill it with their heavy bills" (Fitz Simmons, 1962: 39).

Quoting Burish et al. (See "Abstract": http://synapse.princeton.edu/burish_wang04_bbe.pdf ):

Vertebrate brains vary tremendously in size, but differ- ences in form are more subtle. To bring out functional contrasts that are independent of absolute size, we have normalized brain component sizes to whole brain vol- ume. The set of such volume fractions is the cerebrotype of a species. Using this approach in mammals we pre- viously identified specific associations between cerebro- type and behavioral specializations. Among primates, cerebrotypes are linked principally to enlargement of the cerebral cortex and are associated with increases in the complexity of social structure. Here we extend this analy- sis to include a second major vertebrate group, the birds. In birds the telencephalic volume fraction is strongly cor- related with social complexity. This correlation accounts for almost half of the observed variation in telencephalic size, more than any other behavioral specialization ex- amined, including the ability to learn song. A prominent exception to this pattern is owls, which are not social but still have very large forebrains. Interpolating the overall correlation for Archaeopteryx, an ancient bird, suggests that its social complexity was likely to have been on a par with modern domesticated chickens. Telencephalic vol- ume fraction outperforms residuals-based measures of brain size at separating birds by social structure. Telen- cephalic volume fraction may be an anatomical sub- strate for social complexity, and perhaps cognitive abili- ty, that can be generalized across a range of vertebrate brains, including dinosaurs.

Quoting Walsh (See "Reptiles including nonavian dinosaurs and birds": http://www.academia.edu/1061233/Directions_in_Palaeoneurology ):

It is now clear that while some theropod clades pos-sessed typically 'reptile'-like brains (Giffin et al. 1988; Gif-fin 1989; Rogers 1999; Brochu 2000; Franzosa and Rowe 2005; Sanders and Smith 2005; Witmer and Ridgely 2009), at least some maniraptoran theropods had surpris-ingly bird-like brains (Kundra´t 2007; Balanoff  et al. 2009; Norell et al. 2009). In these taxa, not only is the telen-cephalon significantly enlarged (sometimes to an extent greater than in Archaeopteryx), but flight-related regions such as the cerebellar flocculus, which are especially enlarged in birds, are also very well developed (Kundra´t 2007). This has fuelled the debate about whether these taxa, which often bear feathers, are in fact secondarily flightless birds rather than bird-like theropods (Witmer 2009; Kavanau 2010).

[wings]

2. Because we're doing science, not science fiction, we can't say one way or the other ... given current evidence.

...I'll point out that dromaeosaurs are probably far, far less intelligent than hawks or wolves, based on brain/body ratio (which only goes so far, but it's the best we'll ever do for Mesozoic species)...

...But dromaeosaurs don't match up to modern raptors in terms of intelligence as far as we can tell. So the question then becomes; were these dinosaurs smart enough to hunt in packs? I'm not saying they were dumb but most of the estimates I see compare the intelligence of a Troodon to an opposum. Eagles, hawks and falcons are all pretty smart birds. So while it is refreshing to see someone compare an extinct dinosaur to a living dinosaur instead of a canine the issue of brain size is something to take into consideration...

In saying all these, do we actually know what is the encephalization value ("encephalization quotient" or EQ) range for such behaviour (well, what is the minimum required?)? Was there a study on this or the statement is plainly based on logic? The following quote is from Buchholtz (2012) "... The high encephalization values of small coelurosaurs indicate an active, complex, and social lifestyle that agrees well with their frequent interpretation as pack hunters...". I'm not saying that they (dromaeosaurs) must be pack hunters (the possibility appears to be still open among the scientific community) but using EQ as proof seems to be a little premature since we didn't have a comprehensive understanding (nor reached a settlement) on the subject yet (intelligence among prehistoric animals). If that is the case then...

"...All very sound reasoning. But still zero science. It's not science until you or the researchers propose a way to test these various scenarios and hypotheses. Thinking things through with logic is not testing. Testing is using data try to and prove a scenario wrong..."

[HD-man]

If you recall, I was the first one to mention the notion of the sea turtle method as the only way I can see them abandoning their young. I wasn't 'married' to my earlier idea of them being nurturing parents, I just said it's hard for me to imagine them just leaving their young behind to die unless the "sea turtle" theory is correct. I believe you (or somebody else) did provide a shred of evidence for this, so for now, I'm on board with that theory. So isn't there an agreement between us on that topic?

Okay, so the paper you posted was directly written by the researcher? My mistake then. What I read was an article ABOUT that paper, and in that article, it was mentioned that the particular paper/theory you speak of was "debunked". Debunked how? I do not know. The article didn't get into an specifics on that, unfortunately. I don't think we'll ever find evidence that Dromies DIDN'T hunt in packs - all we'll find is ways of discrediting evidence that they DID hunt in packs, if that makes sense...

I can't believe I didn't notice the above quote the last time I posted in this thread.

1stly (in reference to sauropods), I hope the Naish quote helps. Someone else (I forget who) mentioned the blog post from which it came, but didn't say what/where exactly the relevant info is (which isn't very helpful, given how much info there is in said post).

2ndly (in reference to dromaeosaurids), the closest thing I know of to a formal rebuttal to Roach & Brinkman 2007 ( http://pds17.egloos.com/pds/201004/29/62/Theropod_Dinosaur.pdf ) is Li et al. 2008 (See "Behavior" under "Discussion": http://www.academia.edu/235413/Behavioral_and_faunal_implications_of_Early_Cretaceous_deinonychosaur_trackways_from_China ). Hone et al. 2011 (See "Theropod behaviour and feather origins": http://darrennaish.files.wordpress.com/2013/01/hone-et-al-2012-mutual-sexual-selection-in-dinosaurs-and-pterosaurs.pdf ) & Brusatte 2012 (See "Dromaeosaurids: pack-hunting theropods?": http://books.google.com/books?id=t8dwWakrlm0C&pg=PA173&dq=%22dromaeosaurids+pack%22&hl=en&sa=X&ei=Z_PRUraeM7PhsATbm4CIDA&ved=0CC8Q6AEwAA#v=onepage&q=%22dromaeosaurids%20pack%22&f=false ) also criticize Roach & Brinkman 2007, but to a much lesser extent. I complained about Roach & Brinkman 2007 & gave examples of its many problems in this journal entry: http://jd-man.deviantart.com/journal/SD-Top-4-most-annoyingly-popular-dino-hypotheses-395469447

Quoting Naish ( http://scienceblogs.com/tetrapodzoology/2011/05/12/sauropod-viviparity-meme/#comment-25425 ):

Bakker said in his 1968 Discovery article that the Davenport Ranch sauropod trackway revealed how juveniles had been flanked by protective adults; this claim has been repeated in numerous sources and even illustrated, sometimes with a painting of the trackway as it's meant to look. However, to quote Martin Lockley: "This appealing idea fits in well with the social dinosaur scenario but is only an educated, off-target speculation; there is no trackway evdence for it" (Lockley 1991, p. 79).

In discussing what he called the 'structured herd hypothesis', Lockley (1991) showed that (while sauropod herds may have had a complexity) they mostly show the biggest adults (footprint width c. 50 cm) walking ahead of smaller adults/sub-adults (footprint width c. 30 cm). The tracks of small juveniles are never found among herds, and in fact numerous (often associated) juvenile tracks have been found separate from those of larger animals: more support for the 'pod formation' hypothesis (where babies live together, and separately from adults).

[Splonkadumpocus]

Getting off of dromaeosaurs for a moment (why do all pack-huntning arguments revolve around dromaeosaurs?), I believe there is enough evidence to support the idea that Allosaurus had at least some form of social structure.

Bakker identified two types of kill sites in the Morrison: the normal ones, where teeth of several carnivores are found around the bones of a prey animal, and the "lair" sites, where nearly all of the teeth come from Allosaurus. In the latter, Allosaurus teeth representing all age classes can be found. No lair sites from any other taxon have been found in the formation.

In predator-trap scenarios, field biologists have observed that cries of trapped animals attract pack hunters almost exclusively. This has been applied to the La Brea Tar Pits, where of all the predators, dire wolves and sabertooths are found in huge numbers while other carnivores are much less common. This has been used to argue that sabertooths must have been pack hunters. Apply this to the Cleveland-Lloyd Dinosaur Quarry, where at least 44 individual Allosaurus have been found compared to 1 or 2 individuals of other theropods.

[HD-man]

Getting off of dromaeosaurs for a moment (why do all pack-huntning arguments revolve around dromaeosaurs?),

B/c non-avian maniraptorans probably had the intelligence for pack-hunting (See the 1st Buchholtz quote), while non-maniraptoran theropods probably didn't (See the 2nd Buchholtz quote).

I believe there is enough evidence to support the idea that Allosaurus had at least some form of social structure.

Family groups, probably, but not necessarily hunting groups.

Quoting Buchholtz ( http://www.amazon.com/Complete-Dinosaur-Second-Life-Past/dp/0253357012/ref=sr_1_1?s=books&ie=UTF8&qid=1354904213&sr=1-1 ):

Endocasts of small coelurosaurs (Russell 1969, 1972; Colbert and Russell 1969; Kundrát 2007) display a strikingly different anatomical pattern (Fig. 10.6). They retain details of brain anatomy and roofing bone sutures on their surfaces, suggesting that the brain filled the braincase nearly completely. Brain flexures are minimal and olfactory bulbs are small, indicating that smell was not a dominant sense. Cerebral hemispheres are separable, convex, and expanded laterally and/or posteriorly (Kundrát 2007), suggesting an active intelligence. The large optic lobes are visible either dorsally or displaced laterally by the large cerebrum, as in living birds. Russell (1969) associated the large optic lobes with large eyes and binocular vision, and it is likely that sight was the dominant sense. Kundrát (2007) described an expanded cerebellum with presumptive cerebellar folia among the avianlike characters of the oviraptorid theropod Conchoraptor, inferring excellent balance and coordination.
Encephalization quotients of small coelurosaurs vary with predictions of body mass and percentage of braincase fill, but even conservatively, they are far higher than those of any other dinosaur group, overlapping those of living birds (Hopson 1977; Kundrát 2007). Larsson et al. (2000) estimated cerebral volumes by superimposing ellipsoids on endocasts with surficial indications of cerebral extent. Their data suggest at least three stages of increase of relative cerebral size to total brain size over a period of only 40 million years: of coelurosaurs over allosaurs, of Archaeopteryx over coelurosaurs, and of ornithurine birds over Archaeopteryx. The high encephalization values of small coelurosaurs indicate an active, complex, and social lifestyle that agrees well with their frequent interpretation as pack hunters.

Quoting Buchholtz ( http://www.amazon.com/Complete-Dinosaur-Second-Life-Past/dp/0253357012/ref=sr_1_1?s=books&ie=UTF8&qid=1354904213&sr=1-1 ):

Brain anatomy in theropods is relatively well known and falls into two distinct anatomical groups, suggesting different dominant sensory modalities and lifestyles. Allosaurids and large coelurosaurs retain primitive endocast shape and distinct cerebral and pontine flexures (Fig. 10.2). The optic tectum is obscured and must have been small. The cerebral hemispheres are not separable and show only modest convexity. The prediction of extremely large olfactory bulbs in Tyrannosaurus rex (Brochu 2000) has been scaled downward, but it still seems likely that smell was a dominant sense (Rogers 1998, 1999; Stokstad 2005; Saveliev and Alifanov 2007). Rogers (1998, 1999) described the vestibular apparatus of Allosaurus fragilis, which more closely resembles that of crocodylians than that of lizards, turtles, or birds. He used semicircular canal orientation to suggest that Allosaurus held its head at or very slightly (≤10 degrees) inclined to the horizontal. Burish et al. (2004) included endocranial casts of Tyrannosaurus, Allosaurus, and Carcharodontosaurus in an analysis of relative telencephalic (~cerebral) size and behavior in birds. Their data indicate values for theropods at or below the range of living reptiles, and predict low social complexity.

[HD-man]

2ndly, while ants are technically pack hunters by definition, their pack-hunting is different from that of vertebrates in that it's innate (as opposed to learned), & is thus considered a lower order/less complex level of behavior than that of social foraging vertebrates (pack-hunting or otherwise). If you want, you can do what I do & refer to true cooperative invertebrates as "swarm hunters" (in reference to  their "swarm intelligence"). As for pelicans, they hunt in a pseudo-cooperative manner (To quote Ellis et al., "Piscivorous birds often hunt communally but do not share prey").

In retrospect, I should've said that in my 1st post on page 7. I've since modified said post accordingly so as to avoid confusing anyone else (although I'm still not sure whether Dinoguy2 was really confused or just trolling).

Quoting Tudge ( http://www.amazon.com/Bird-Natural-History-Birds-Where/dp/B007K4GP1W/ref=la_B000APQE3M_1_2?ie=UTF8&qid=1354947277&sr=1-2 ):

The sociality that is encouraged by the diet tends to spill over into all aspects of life. So it is that hornbills are fruit eaters and also, as we will see in Chapter 7, are outstandingly social breeders, with various kinds of social arrangements. But also among hornbills we see an interesting twist—where the innate sociality has in turn become adapted to a quite different kind of feeding. For among the biggest of all hornbills, and in various ways distinct from the rest, are the two species of ground-hornbills from Africa. Ground-hornbills are not mere fruit eaters: they are formidable predators. The beak is like an icepick. They can hack their way into a tortoise. The Northern species is among the biggest of all avian predators. The ancestors of ground-hornbills were presumably fruit eaters, and that, perhaps, is how they first evolved their sociality. Now, as predators, they hunt in packs. Typically they chase some hapless creature like a hare into a bush and then some act as beaters while others lie in wait and deliver the coup de grace. The packs are usually family groups. They can be seen as strategic predators like wolves or perhaps as problem families, terrorizing the neighborhood.

I've since found video of ground hornbills pack-hunting a rabbit just like in the above quote, but with an eagle.

https://www.youtube.com/watch?v=K4zs0_A0hy4

[ITdactyl]

thanks for sharing that vid.... "raptor snatches mammal from marauding azhdarchids" lol

[HD-man]

thanks for sharing that vid.... "raptor snatches mammal from marauding azhdarchids" lol

That's a good idea for a subplot in a WWD episode: 1st, a lone Qutzalcoatlus steals from a Saurornitholestes pack; Later, said Quetzalcoatlus dies & is scavenged by said pack (in reference to Currie & Jacobsen 1995: http://www.nrcresearchpress.com/doi/abs/10.1139/e95-077#.VBztw0teTwI ).

[amargasaurus cazaui]

Ive a question here if i might....and to clarify right up front therapods are not my general cup of tea so I do not know for sure, just asking those who are more therapod friendly....but is there fossil evidence linking multiple dromeosaurs or raptors to a group or herd...(flock) (peck) group of any kind, other than "The Shrine" which has been so central to the discussion? Not looking so much for a kill site as perhaps a casual life group of some sort  as sometimes found in Hadrosaurs, ceratopsians and sauropods? Definitely not challenging anyones conclusions in this thread, and asking out of complete ignorance...thanks

[HD-man]

Ive a question here if i might....and to clarify right up front therapods are not my general cup of tea so I do not know for sure, just asking those who are more therapod friendly....but is there fossil evidence linking multiple dromeosaurs or raptors to a group or herd...(flock) (peck) group of any kind, other than "The Shrine" which has been so central to the discussion? Not looking so much for a kill site as perhaps a casual life group of some sort  as sometimes found in Hadrosaurs, ceratopsians and sauropods? Definitely not challenging anyones conclusions in this thread, and asking out of complete ignorance...thanks

Like a family group? Just making sure.

[amargasaurus cazaui]

Ive a question here if i might....and to clarify right up front therapods are not my general cup of tea so I do not know for sure, just asking those who are more therapod friendly....but is there fossil evidence linking multiple dromeosaurs or raptors to a group or herd...(flock) (peck) group of any kind, other than "The Shrine" which has been so central to the discussion? Not looking so much for a kill site as perhaps a casual life group of some sort  as sometimes found in Hadrosaurs, ceratopsians and sauropods? Definitely not challenging anyones conclusions in this thread, and asking out of complete ignorance...thanks

Like a family group? Just making sure.

Family group, small herd, sunday church gathering, a close association of several indivduals preserved as a group.....perhaps a bowling team? lol

[Dinosaurana]

Not to be a stickler or anything, but this is a bit relevant.

http://www.sci-news.com/biology/science-crocodiles-alligators-hunt-groups-02203.html

Wasn't where I originally found it, but it shows across species interactions of group hunting behavior. Not in large packs mind you, but coordinated behavior. And as birds also tend to group and also have been noticed in various species to use coordinated attacks, I would not be surprised if some things like these happened.

[HD-man]

I hope you guys don't mind me posting in this thread given how old it is. It's just that pack hunting came up a lot when I shared "The Saurian Dakotaraptor could be better" in "The Prehistoric Times Public Group | Facebook" (which is weird b/c I didn't mention pack hunting at all in my post: https://www.facebook.com/groups/16791880228/permalink/10155902497165229/ ). This inspired me to modify my 1st pack-hunting post on page 7 ( http://dinotoyblog.com/forum/index.php?topic=375.msg38801#msg38801 ) to be better written/more informative. I hope I was able to help.