Egyptian Chariots – Part 2 of 2

It is the post-Hyksos era of the New Kingdom that begins to see chariot used on a grand scale, however. Chariots were used in large numbers at Megiddo by Thutmose III, possibly as the first chariotry division which employed archers in a mobile fashion (Brewer & Teeter 1999). Drews (1993) indicated that the Battle of Megiddo is testament that a king could make use of over 1000 chariots in a single operation and that the Battle of Kadesh was similarly provisioned with sufficient forces to face over 2500 Hittite chariots. Drews attributed the success of Ramesses II to the skill of charioteers as archers and part of two-man archer/shield-bearer teams, which was an advantage over the Hittites’ three-man chariot teams. The Hittites, according to Ramesside reliefs cited by Drews, consisted of a driver, a shield-bearer, and a javelin-thrower. Spalinger (2005) suggests that the driver, who doubled as the archer, was protected by the shield-bearer and the two men worked as a team.

Littauer and Crouwel (2002) take a stark contrast to Drews (1993) with regard to the way chariots were employed in battle. Drews maintains that Bronze Age warfare was, essentially, chariot warfare with armies facing off with divisions of chariots numbering in the thousands, augmented by infantry and runners. Littauer and Crouwel, however, contend that the chariot was expensive and difficult to maintain, required specialized training for both equids and charioteers, and was unwieldy during battle. Their position was that chariots were used as a means of “conspicuous display of great powers such as Egypt or the Hittite empire,” and a means to assist the main force of the military.

With regard to the “conspicuous displays” hypothesis, there is ample supporting evidence. Reliefs of Pharaohs with their chariots are nearly always in grandiose style with the Pharaoh depicted in the position of being about to release an arrow from his bow (Drews 1993, pls. 1, 6, 7, 9, 10; Partridge 1996, figs. 92, 97, 98, 112; Smith , fig. 364). Epigraphic accounts of the pharaohs’ chariots are equally grandiose:

His majesty set forth in a chariot of fine gold, adorned with his accoutrements of combat, like Horus, the Mighty of Arm, a lord of action like Montu, the Theban, while his father Amon mad strong of his arms. […] [t]hen they saw his majesty prevailing over them, and they fled headlong [to] Megiddo with faces of fear (Pritchard 1958, p. 175).”

Photo by mharrsch

Littauer and Crouwell (2002) surmise that the chariot is limited by extremes in terrain, including mud, rocks, sand, bogs, or hilly, and would not be effective in utilitarian endeavors such as equine herding or hunting in the wild. The chariot, costly to build and maintain, would have been inferior to the mounted rider. Moreover, they argue that it would have been far easier to replace an individual horse than it would a draught team. For these reasons, Littauer and Crouwell raise the question: why the chariot? They then suggest that a “stimulus other than necessity must be found (p. 47).” The burial goods of elites, especially kings and pharaohs, in the Near East included chariots and their accoutrements according to Postgate (1994), who also construed this to mean that their value was mainly symbolic and seemed, in Mesopotamia, that chariots were part of ceremonial or ritual use for the gods. Littauer and Crouwell (2002) referred to wheeled vehicles, based on their representations, as “conveyances of the gods (p. 48).”

The tomb of Thutmose IV in the Valley of the Kings was found by Howard Carter to have still contained a chariot body, which was badly damaged by looters who stripped away the original gold or silver surface (Partridge 1996). The find was still important, however, because the underlying plaster of the body still held the images of the interior and exterior scenes that would have been rendered in precious metal. The exterior scenes depict the Pharaoh riding his chariot in battle with Asiatics, firing arrows in one scene and swinging an ax in the other. The chariot depicted in the scenes is one of eight-spoke wheels and has a quiver for arrows on either side with a bow sheath on the right. The interior scene depicts the Pharaoh as a sphinx, stepping on his enemies. Pharaohs weren’t the only elites buried with their chariots, however. The parents-in-laws of Amenhotep III, Yuya and Thuya, died at around 1365 BCE and, in their tomb in the Valley of the Kings, was a small chariot. Yuya was known to be the Commander of Chariots and the chariot itself was found with solidified lubricant derived of animal fat on the axle (Partridge 1996).

The six chariots found in the tomb of Tutankhamen are the most complete examples of actual chariots from the New Kingdom and are testament to the grandiose style of the Pharaoh with full decoration of gold inlays and were actual chariots used by the Pharaoh before his death (Partridge 1996). The chariots were completely disassembled and the pieces stacked almost haphazardly with four in the antechamber and two in the treasury of the small tomb and were labeled by Howard Carter as A1 through A6. Among the other grave goods in the tomb were accoutrements such as whips, yoke saddles, and blinkers for the horses’ eyes (Littauer & Crouwel 1985; Partridge 1996).

It has been suggested that the chariots found in Tutankhamen’s tomb are examples of superior engineering and capable of informal racing by Sandor (2004). Sandor refers to the engineering and implementation of the design of the “Tutankhamen-class” chariot to be a “remarkable achievement.” Specifically, Sandor cites the innovations of the “bow-and-arrow” horizontal shock absorber, which assists in preventing rollover as well as smoothing the ride; V-spokes of the wheels; and joint systems in the wheels that have “aircraft-like damage tolerance.”

The chariot may or may not have been introduced to the Egyptians by the Hyksos as some have variously suggested or implied both ways. It is clear, however, that the chariot was an important technology to the New Kingdom and had significance in defining or at least highlighting elite status and the chariot probably held some religious significance as a conveyance of the gods based on its inclusion with burial items.

For references, see the end of Part 1

Homo floresiensis Update: Not a Hobbit?

"LB1 is not a normal member of a new species, but an abnormal member of our own," or so concludes Dr. Robert B. Eckhardt, professor of developmental genetics and evolutionary morphology, department of kinesiology, Penn State.

I’ve previously posted about Homo floresiensis (a.k.a. the Hobbit):
New Species or Modern Human? and
Stone Tools of a New Hominid Species?.

Afarensis has also made several posts:
Homo floresiensis: More on Microcephaly
Stone Tools and Homo floresiensis
Tis a Puzzlement: More on Homo floresiensis
The Loom on the Hobbit

And Carl Zimmer’s post, Hobbit as a Monkey? is well worth the read if you are following this topic.

The Eckhardt quote above can be found at this recent Eureka Alert , however.

A research team headed by Teuku Jacob (laboratory of bioanthropology and paleoanthropology, Gadjah Mada University, Indonesia), which included Eckhardt and others, was granted permission to analyze LB1, the nearly complete remains of the individual they now say is mislabeled H. floresiensis. They also had access to the remains of other individuals found at the same site.

The team has published a research article that can be viewed at the Proceedings of the National Academy of Sciences, " Pygmoid Australomelanesian Homo sapiens skeletal remains from Liang Bua, Flores: Population affinities and pathological abnormalities. "

In the article, Jacob et al summarize the evidence against a new species as the following:

  1. Demography, Continuity, and Isolation. The contention that a new species, H. floresiensis, evolved in extended isolation, which would require that migration to the island could only have occurred once and in large enough numbers to have provided sufficient genetic diversity to allow a sustained population of a new species in a very short period of time. The evidence of stegadon migration would indicate that humans couldn’t have been restricted to a single migration. Basically, there wasn’t enough resources to support a population large enough to provide enough genetic diversity for the alleged founder group and yet keep them in isolation long enough (tens of thousands of generations).
  2. Neurocranium and Face. None of the features and characters of the LB1 cranium or the two available mandibles are "outside the range for modern humans of the region." Microcephaly provides the explanation for the small cranium and is indicated by the closure of cranial sutures. In addition 10 other examples of microcephalic skeletons are referred to, noting that none their abnormalities are used to establish new species.
  3. Dentition. Premolar crown rotation and other dental characteristics are consistent with modern pygmies in the Liang Bua region.
  4. Postcrania. Abnormality is evident throughout the postcranial skeleton, particularly with the leg bones. CT scans of leg bone cross sections reveals that the cortical bone is thin (~2 mm), abnormal for any primate over 1 meter tall. This and other features indicate that LB1 is anything but robust, as previously described by others. Deltoid tuberosity of the humerous is nearly absent and the difference in width between the subdeltoid and supradeltoid is small, indicative of weak muscle development.

I must say, Jacob et al present a good case for arguing that others were premature in attempting to establish a new species.

And the article is free via open access!

Jacob, T; Indriati, E; Soejono, R.P.; et al (2006). Pygmoid Australomelanesian Homo sapiens skeletal remains from Liang Bua, Flores: Population affinities and pathological abnormalities. Proceedings of the National Academy of Sciences, 103 (36), 13421-13426.

The Egyptian Chariot: Part 1

Chariot Photo by stinkerbell1

Chariots are frequent subjects of Egyptian art and are nearly always depicted as an instrument of war or hunting with the Pharaoh in a grand pose about to lay waste to an enemy or slay a wild beast (fig. 1). Among the many representations of chariots in Egyptian art, are those found in the tombs of Ahmose at Abydos (Spalinger 2005), the Userhet, a royal scribe of the 18th Dynasty (Lloyd 1961), Khaemhet, Amenhotep Huy (Smith 1998), Tutankhamen (Smith 1998; Partridge 1996; Littauer & Crouwel 1985), and Thutmose IV (Partridge 1996) among others. Chariots are also found in temple art such as the depictions of Seti I on the exterior wall of the Hypostyle Hall at the temple of Amun at Karnak mounting his vehicle then trampling his enemy at Kadesh (Partridge 1996; Smith 1998). There are also a few artifacts of chariots that have proveniences from the pharaonic tombs of Amenhotep II, Thutmose IV, and Amenhotep III as well as the tomb of Yuya and Thuya, the parents-in-law of Amenhotep III (Littauer & Crauwel 1985; Partridge 1996). The first intact chariot was discovered in 1829 in a tomb whose owner remains unknown and is now on display at the Museo Archeologico in Florence, Italy (Littauer & Crouwel 1985). The Florence Chariot (fig. 2) has wheels of four spokes and is considered to be of earlier construction and design than other chariots found, which have six spokes (Partridge 1996).

While the exact date of the Florence Chariot’s tomb may not be known Partridge (1996) suggests that it probably originated from early in the 18th Dynasty, there is epigraphic evidence of chariot use in Egypt during the reign of Ahmose I at the beginning of the same Dynasty. In the biography left in the tomb of Ahmose, son of Eben, a military elite under the Pharaoh Ahmose and later Thutmose I (Spalinger 2005; Pritchard 1958), descriptions of his exploits in expelling the Hyksos from Egypt include mention of chariotry, though in a brief, even casual manner:

“I served as soldier in his place in the ship, “The Wild Bull,” in the time of the Lord of the Two Lands: Neb-pehti-Re, the triumphant, when I was (still) a boy, before I had taken a wife […] But after I had set up a household, then I was taken on the ship, “Northern,” because I was valiant. Thus I used to accompany the Sovereign -life, prosperity, health! -on foot, following his excursions in his chariot” (Pritchard 1958, p. 173).

Ahmose, son of Ebana, makes no direct mention of Egyptian use of chariots as war machines or in battle and Pritchard comments that the chariot is introduced to the Egyptians by the Hyksos.

The Hyksos first appear in Egypt during the Second Intermediate Period, 1782-1570 BCE (Brewer & Teeter 1999), and began occupying the Eastern Delta region. The term “Hyksos” is derived from hk hswt, referring to “foreign rulers” of Asiatic lands. Van Seters (1966) discusses in detail the argument of Wolfgang Helck that the Hyksos were of Hurrian or Indo-Aryan origin and part of an invasion or massive immigration with the intent to occupy and dominate Egypt, based largely on the account of Manetho as retold by Flavius Josephus. Van Seters contends that Helck’s arguments are dubious and speculative and notes that the linguistic, archaeological, and epigraphic evidence points to Semitic, probably Canaanite, origins for the people that have come to be known as the Hyksos. Van Seeters argues that the name Salitas as indicated by Manetho is the Semitic title “sultan.” Likewise, he points out that the name of a slave given to Ahmose, the son of Ebana, is Ishtar-ummi, and of West-Semitic origin. Ahmose, son of Ebana, participated in several raids on Avaris in which he took hands of his enemy as well as live captives, which Ahmose, the Pharaoh, awarded him as slaves along with “The Gold of Valor” on at least two occasions (Pritchard 1958).

The Hyksos, however, are frequently attributed as having introduced the chariot and the composite bow to the Egyptians (Lloyd 1961; Van Seters 1966; Brewer & Teeter 1999; Drews 1993; Partridge 1996; Spalinger 2005). Van Seters concedes that this is a compelling argument for the possibility of at least an element of Hurrians within the Hyksos, which isn’t a term specific to a single ethnicity to the Egyptians, but to foreigners in general, particularly Asiatics (Van Seters 1966; Brewer & Teeter 1999). As already noted, the chariot was described by Ahmose, son of Ebana, in context of the siege of Avaris by Pharaoh Ahmose. But warfare at this point depended upon rapidly moving large numbers of troops via ships on the Nile (Spanlinger 2005) rather than attacking with fast-moving chariot divisions. Indeed, Spalinger along with Littauer and Crouwel (2002) point out the difficulty that chariots would have on any terrain but smooth, level and dry surfaces. The Nile Valley itself is considerably less forgiving to the easily tipped or stuck in the mud chariots and devoid of the wide-open spaces characteristic of Syria and Palestine, which would be faced by Egypt later (Spalinger 2005). Littauer and Crouwel (1985) make note of the “second stela” of Kamose and its mention of the “chariotry” of the pharaoh’s enemies, but they also raise the question of interpretation of that stela. His Hyksos enemies may or may not have had chariots, but it seems reasonable to assume, however, that Pharaoh Kamose might have when evidence exists that his brother and successor Ahmose did (Harvey 1998).

Battle scene fragments from the walls of the Ahmose Temple at Abydos (fig. 3) are close in composition to those of the temples of Thutmoses I and II (fig. 4) such that the later Thutmoside scenes may have been influenced by those at the Ahmose Temple. The Ahmose images clearly indicate four-spoke wheels, while some Thutmoside images show four-, six-, and eight-spoke wheels. Those of the pharaoh in Thutmoside images are clearly eight-spoke wheels, while the Asiatics in the same images are depicted as much smaller in stature than the pharaoh and their chariots have only four spokes (Harvey 1998). The Ahmose Temple images are the earliest depictions of chariots in Egypt (Harvey 1998; Spalinger 2005) and include no depictions of Hyksos chariots nor does the biography of Ahmose, son of Ebana, speak of chariots used by the Hyksos.

The chariot, however, is certainly an imported technology from outside Egypt and from the East based on design and materials (Littauer and Crouwel 2002, 1985; Partridge 1996; Spalinger 2005). According to Littauer and Crouwel the Egyptian chariot followed design trends of Assyrian models in being “small, fast two-man” vehicles (2002) and assert that both the chariot and the horse in Egypt are imported from the Levant (1985). Partridge notes the materials used in chariot construction, such as elm and birch, were not native to Egypt and implied some level of trade with sources outside of Egypt. According to Spalinger, the Asiatic and Egyptian chariots of the early 16th and 15th centuries BCE are “virtually identical” and that their suitability for use in arid regions “should alert us to the origins outside of the so-called ‘Fertile Crescent’ (p. 13).”


Brewer, D. J., & Teeter, E. (1999). Egypt and the Egyptians. Cambridge: University Press.

Drews, R. (1993). The End of the Bronze Age: CHanges in Warfare and the Catastrophe ca. 1200 B.C.. Princeton, New Jersey: Princeton University Press.

Harvey, S. P. (1998). The Cults of King Ahmose at Abydos (Diss, University of Pennsylvania, 1998). Dissertation Abstracts International, p. 1231A.

Littauer, M., & Crouwel, J. (1985). Chariots and Related Equipment from the Tomb of Tutankhamun. Oxford: Griffith Institute.

Littauer, M., & Crouwel, J. (2002). The Origin of the True Chariot. In P. Raulwing (Ed.), Culture and History of the Ancient Near East. Vol. 6: Selected Writings on Chariots and Other Early Vehicles (pp. 45-52). Leiden: Brill Academic Publishers.

Lloyd, S. (1961). The Art of the Ancient Near East. New York: Frederick A. Praeger.

Partridge, R. (1996). Transport in Ancient Egypt. London: Rubicon Press.

Postgate, J. (1994). Early Mesopotamia: Society and Economy at the Dawn of History. New York: Routledge.

Pritchard, J. B. (1958). The Ancient Near East Volume I: An Anthology of Texts and Pictures. Princeton, NJ: Princeton University Press.

Sandor, B. I. (2004). The rise and decline of the Tutankhamun-class of chariot. Oxford Journal of Archaeology, 23(2), 153-175.

Smith, W. S. (1998). The Art and Architecture of Ancient Egypt. New Haven and London: Yale University Press.

Spalinger, A. J. (2005). War in Ancient Egypt: The New Kingdom. Malden, MA: Blackwell Publishing.

Van Seters, J. (1966). The Hyksos: A New Investigation. New Haven and London: Yale University Press.

Howler Monkeys Part 4: References and Cited Works

I hope if you read this far in this four part series, that you enjoyed reading about one of the most enigmatic New World monkeys. Below is the list of works cited in the previous three parts, but I’m also going to include a few sources that are Internet accessible for those without quick access to the books and journal articles.

Internet Sources

Google Image Results for “howler monkey”

Wikipedia Entry for howler monkey. This link includes some images including the one used to show schizodactyly.

Honolulu Zoo Fact Sheet

The Loudest Animal In the World, an article by Terry Dunn hosted by the Smithsonian National Zoological Park website.

Cited References

Carpenter, C. R. (1934). A Field Study of the Behavior and Social Relations of Howling Monkeys. New York: AMS Press.

Fleagle, J. G. (1999). Primate Adaptation and Evolution, 2nd Ed.. San Diego, CA: Academic Press.

Gilbert, K. A., & Stouffer, P. C. (1989). Use of a ground water source by mantled howler monkeys (Alouatta palliata). Biotropica, 21(4), 380.

Kinzey, W. G. (1997). New World Primates: Ecology, Evolution, and Behavior. New York: Aldine De Gruyter.

Kitchen, D. M. (2004, 19/03). Alpha male black howler monkey responses to loud calls: Effect of numeric odds, male companion behavior and reproductive investment. Animal Behavior, 67, 125-139.

Milton, K. (1980). The Foraging Strategy of Howler Monkeys: A Study in Primate Economics. New York: Columbia University Press.

Pinto. Liliam P., & Setz, E. Z. (2004, December). Diet of Alouatta belzebul discolor in an Amazonian rain forest of Northern Mato Grosso State, Brazil. International Journal of Primatology, 25(6), 1197-1211.

Regan, B. C., Julliot, C., Simmen, B., Viénot, F., Charles-Dominique, P., & Mollon, J. (1998, November). Frugivory and colour vision in Alouatta seniculus, a trichromatic platyrrhine monkey. Vision Research, 38(21), 3321-3327.

Richard-Hansen, C., Vié, J.-C., & de Thoisy, B. (2000). Trnaslocation of red howler monkeys (Alouatta seniculus) in French Guiana. Biological Conservation, 93, 247-253.

Howler Monkeys Part 3: Vocalizations

Howler Photo by JeanKearn

Perhaps the most familiar characteristic of the howler monkey are their vocalizations for which they are named. Howlers, both male and female, use their loud, lion-like roars (Fleagle 1999 p150) to advertise their presence and to warn or intimidate intruders (Kitchen 2004). Vocalizations may also provide auditory cues that reveal fighting ability of a group or an individual (Kitchen 2004). Vocal battles may culminate or result in actual physical combat in which an intruder makes an effort to usurp the group’s alpha male. Most howler troops consist of several adult males, but have a single alpha male that mates with the troop’s females, putting any dependent offspring in the alpha’s lineage. The immigrant male that forcibly replaces the group’s alpha can kill the dependent infants of the ousted alpha male (Fleagle 1999, p152; Kitchen 2004, p126). Infanticide of offspring under 9 months old hastens the female’s return to estrus, allowing the immigrant alpha male the opportunity to establish his own lineage according to data that is both circumstantial and observational (Kitchen 2004).

The Influence of Offspring

Kitchen discovered that the presence of small offspring had an influence on the alpha male’s vocal responses in that the alpha was quicker to begin howling, howled more often, and for longer periods when small offspring were present in the group. If the odds were against the alpha, howling was done only when small offspring were present, suggesting that an assessment was made by the monkey regarding the value of winning before escalating the conflict. Kitchen concluded that howling displays are costly with regard to energy, but the benefits outweigh the costs if intruders can be impeded. She also noted that males of small offspring stood their ground and, while did not advance upon aggressors, did not flee, indicating that stationary displays might be a compromise between fight and flight.

Keepin’ it on the ‘Down Low’

Kitchen also observed that howlers didn’t always respond to howling neighbors during natural encounters. This, she reasoned, could be due simply to conservation of energy since the howler’s diet limits activity. In general, howlers spend more than 60% of their day resting (Milton 1980; Kitchen 2004). Kitchen also suggested that the lack of vocal response could be a part of a strategy to remain hidden and quiet not only to conserve energy but to avoid facing superior opponents, which could, in turn, suggest that acoustic characteristics might be present in vocalizations which reveal fighting ability.

Loud calls occur most frequently at dawn and may serve the purpose of announcing a group’s location, establishing territory and distance between groups, and revealing a group’s actual composition. They can also serve the purpose of strengthening pair bonds between mates through “duets.” Vocalizations at night, however, occur at a higher rate than the day and calls have been measured to be as high as 90 dB and below 1 kHz (Kinzey 1997).

Conservation and Protection for the Howler

Howlers are reported to have been preyed on by both the harpy eagle and the jaguar (Kinzey 1997), but their most serious threat is, perhaps, habitat loss due to human activity. The construction of the Petit Saut hydroelectric dam in French Guiana flooded over 365 square kilometers of forest by 1995 destroying the natural habitats of many species, including that of the red howler (Richard-Hansen, Vié, and de Thoisy 2000). The red howlers in the inundated habitat were previously hunted to the point of serious reduction of population and the decision was made to translocate the remaining groups in the region to a new habitat. Though all but one of the translocated groups split up after being released in a new home range, the overall operation was considered a success since many of the distinctive behaviors of individuals within the groups were re-observed following the translocation. Richard-Hansen, Vié and de Thoisy (2000) demonstrated that such translocations were viable in situations of habitat destruction or other conservation needs exist.

Howler Monkeys Part 2: Dietary Needs and Habits

Howler Photo by princessangel

Milton’s Study on and Island in the Panama Canal

Milton studied two groups of mantled howlers on Barro Colorado Island in the Panama Canal (1980) and discovered that while howlers don’t have to pursue their foods, neither can they use a “sit and wait” strategy. Their preference for seasonal foods presents them with a continual problem of locating foods they like. Food location and monitoring was their main reason for travel and the alpha male in her study groups would initiate travel with a “low, almost inaudible, cough (p. 102).” The members of the troop would gather in one area of a tree and move out, single file, in a direction indicated by the alpha male. The troop’s travel through trees was in single file, which suggested to Milton a “goal-oriented” endeavor rather than a phalanx formation as with other primate species that would want to cover as much area as possible in their search for food. She also notes, however, that the single file is less risky because the relatively massive howler monkey is in danger of falling should it grab a branch that is brittle or dead, which breaks. The single file formation could be a method of providing a safe, proven route for the troop and the troop often used the same routes for other travel events, reinforcing this hypothesis.

Recharging the Batteries

In Milton’s study (1980), 90% of all travel events were followed by feeding events. She found that her observed groups traveled 1.23 mean hours per day at a mean distance of 443 meters at a mean rate of 360 meters per hour and she referred to howlers as “travel minimizers.” The howlers slept wherever they happened to find suitable spots at nightfall and at their last feeding location. While feeding, howlers generally orient themselves around 1 or 2 “pivotal” trees, moving to different pivotal trees once depleted.

Milton (1980) reported that, of the Howlers she observed during her Barro Colorado Island study, 91.4% of their feeding time was spent on seasonal foods: young leaves, fruits and flowers. They spent 1.6% of their feeding time on perennial foods or foliage that could be considered mature even though perennial foods were more abundant than seasonal and always available, showing a clear preference for specific foods. In a study along the Teles Pires River in Brazil (Pinto and Setz 2004), red-handed howlers (Alouatta belzebul discolor) were similarly observed to prefer seasonal fruits, leaves and flowers over perennial in which the howlers of the study spent 72-92% of their feeding time on the seasonal foods even though perennial were always available. Kinzey (1997) noted that howlers “are either folivore-frugivores or frugivore-folivores, depending on the population and season (p. 179).” He also indicated, as Milton did, that there are food preferences that influence the decisions of howler foraging strategies and that young leaves are preferred over mature but that there is clear exclusivity correlated to seasons, habitat, species and populations within species. At times, howlers prefer fruits or flowers over leaves, while during the same season but in different habitats, the same species might prefer leaves over fruit. Kinzey cites an unpublished dissertation that revealed the howlers of the study required 15.6% of their diet to consist of protein and that this is a driving force in their food choices.

Couch Potatoes?

The howler diet limits their activity and, indeed, dominates it. On average, howlers spend over 60% of their day resting and traveled mainly to locate or monitor food sources (Milton 1980). Howlers of the Barro Colorado (Milton 1980) and the Teles Pires (Pinto and Setz 2004) both preferred products of species of Ficus: leaves, fruits and flowers. However, they were also noted to feed on other species as well. Milton documented 87 leaf sources, 36 fruit sources, and 25 flower sources in her study of the mantled howler while the red-handed howlers in the Pinto and Setz study consumed leaves from 27 sources, fruits from 35 sources, and flowers from 8 sources. Milton observed to eat some leaf species only once, however, and hypothesized that the monkeys could have been sampling other leaf sources within their habitat and, perhaps, gauging them for palatability and nutritional value. She cited the specialized receptors in rats that can recognize potential nutrient-rich foods, sending information to the central nervous system and suggested that Alouatta may have a similar adaptive function. Howlers also appear able to detoxify secondary compounds in food sources, such as terpene, an unsaturated hydrocarbon found in plants. Other New World primates haven’t developed this function (Milton 1980).

See-Food Diet

Trichromatic primates, which include humans as well as Alouatta, have three specialized cones for color vision (Fleagle 1999, pp. 25-26). In a study of the red howler, in the rainforest of French Guiana, (Regan et al 1998), it was concluded that trichromacy in Alouatta allows howlers to locate and identify fruits among foliage from long distances. Regan et al admitted that, while their results were conclusive with regard to the ability of red howlers to consistently identify specific fruits and that specific fruits were optimally colored, they could not demonstrate whether trichromacy was an evolutionary adaptation to the fruit or whether the fruit colors were adapted to the trichromacy. The did, however, underscore the unknown cause of dichromacy among other Platyrrhines, where there are only two color cones rather than three, thus limiting the ability of dichromats to see certain colors effectively.

Washing it all down? Not for the Howler.

Howlers generally obtain water from their food (Carpenter 1934; Milton 1980; Kinzey 1997; Gilbert and Stouffer 1989), leaves and fruit can contain up to 95% water by weight or from arboreal sources following a rain where the monkeys lick their fingers after wetting them in the runoff (Carpenter 1934). Rarely, howlers have been observed coming to drink at standing ground water sources (Gilbert and Stouffer 1989; Carpenter 1934), but in a very cautious manner. The observation by Gilbert and Stouffer was that the monkeys left the trees one at a time to drink with a male, probably the alpha, standing watch. They hypothesized that the dry conditions of that year imposed a water stress that inhibited growth of new leaves, forcing the howlers to obtain water from other sources.

Howler Monkeys Part 1: General Characteristics

 Afarensis has been doing his weekly “Know Your Primate” series, so I hope he won’t mind if I toss in my bit on the howler monkey. It was his series that inspired me and reminded me that I had this from a paper I wrote a while back. I’ll post this in two, maybe three, parts with references and I hope the information will be of value to students writing high school and college papers or for those who are simply fascinated by primates or howlers in particular. Please also feel free to comment on these posts as well!

Howler Photo by lemai13

Taxonomy and morphology

The howler monkey consists of six separate, allopatric species in the family Atelinae of the infraorder Platyrrhini: Alouatta seniculus (red howler), A. belzebul (black-and-red howler), A. fusca (brown howler), A. pigra (Mexican black howler), A. caraya (black howler), and A. palliata (mantled howler).

The Ateline genera also include woolly monkeys, spider monkeys, and the woolly spider monkey along with the howler. Atelines are the largest of the Platyrrhines and the largest average 10 kg. All Atelines have long, prehensile tails with friction ridges used in gripping tree branches during climbing and suspension. According to Fleagle (1999, p 150), Atelines exhibit similarities to extant apes with regard to many characteristics of their limb and trunk anatomy and suspensory behavior.

Of the Atelines, the howling monkeys (Alouatta) are the most distinct genus (Fleagle 1999 p150) and are often placed in a separate subfamily. Their distribution is wide-ranging from southern Mexico to northern Argentina. Their biomass ranges from 6 to 10 kg and color differences can be distinctive between and even within species. Fleagle notes that the colors range from red to brown and from black to blond (p150). Howler dentition includes small incisors and large, sexually dimorphic canines. The lower molars consist of a narrow tigonid section and a large talonid while the upper molars have four cusps with prominent shearing crests consistent with a foliverous diet.

The howler skull consists of a relatively small cranial capacity and a lack of cranial flexion. The mandible is large and deep and an enlarged hyoid bone creates a hollow resonating chamber where the howler’s characteristic vocalizations are produced. Post cranial characteristics include forelimbs and hind limbs that are similar in length, a long, prehensile tail, and schizodactyly caused by a poorly differentiated thumb, which facilitates grasping branches between the second and third digits, but precludes fine manipulation of objects (Fleagle 1999; Milton 1980; Kinzey 1997). The howler prehensile tail reduces the need for leaping or jumping, which have higher energy costs and provides the monkey with an additional appendage in distributing its weight during arboreal activity. The howler can also use the tail to suspend itself from branches to obtain otherwise inaccessible foods (Milton 1980).


Howler habitat is varied because of the wide distribution of the six allopatric species and includes primary rain forests, montane forests, deciduous forests, secondary forests and llanos. They live at altitudes that range from sea level to 3200 meters and prefer the canopy levels of forests, though species in the dryer habitats regularly come to ground and cross open areas as they travel between patches of forest. Locomotion with howlers is generally slow and quadrapedal and they rarely leap. Howlers use suspensory locomotion, mostly climbing, during feeding and occasionally during travel (Fleagle 1999).

Social Behavior

Socially, howlers live mostly in groups of several adults of both males and females with dependent offspring. The size of the group varies dependent upon the productive value of the environment as well as the age of the group, and can range from 12 to 30 individuals as with A. palliata and smaller troops as with A. seniculus and A. caraya. Depending upon the group’s size, the howler home range can be between 10-50 acres and their day ranges are small at less than 100 meters. The home range is considered to be small for their biomass (Fleagle 1999, p. 150) and some can be as little as 3 to 15 acres depending upon species and habitat with up to 60% overlap between one or more groups (Kitchen 2004). Range needs are met more easily because of their ability to subsist on diversified food items which are very common such as leaves. Because of their small ranges, howlers travel little but spend long periods resting and digesting (Fleagle 1999; Milton 1980; Kinzey 1997).