Cassowary (Casuarius spp.) Fact Sheet: Physical Characteristics

Body measurements

*Biggs (2013) states that female Southern Cassowaries can reach 70 kg (154 lb).

Sources
Southern Cassowary: Biggs (2013); Folch et al. (2017a); weight data from Latch (2007)
Northern Cassowary: Folch et al. (2017c)
Dwarf Cassowary: Folch et al. (2017b); weight data from Mack and Jones (2003) and Andrew Mack, personal communication, 2017

(Coates 1985; Biggs 2013; Pratt and Beehler 2015; Folch et al. 2017a; Folch et al. 2017b; Folch et al. 2017c, and as noted)

Body and wings

• Flightless bird; wings and tail feathers very short
• 1.0-1.7 m (3.2-5.6 ft) tall
• Similar to ostriches, emus, rheas, and kiwis in body shape
• Small, “reptilian-like” claw on second digit of each wing

Head and neck (adults)

• Prominent, laterally compressed casque on top of head
  • Shape and size varies (sometimes geographically)
    • Appears helmet-shaped from the side
    • May be curved, peaked, triangular, or flattened
  • Many functions proposed; a 2019 study suggests casque radiates heat during hot weather (Eastick et al. 2019)
    • Possibly additional functions as a social ornament of age, sex, and status and in producing sound (Naish and Perron 2014)
      • May be the product of mutual sexual selection (both sexes evaluate partners on basis of mate quality)
  • Casque structure
    • Internal web of fragile, bony tissue (similar to trabecular bone), protected within denser bone layer and a rigid, external keratinous sheath
      • Outer surface resembles hoof or tortoise shell material (Richardson 1991)
      • Internal structure complex; few studies conducted (Crome and Moore 1988; Mack and Josh 2003; Naish and Perron 2014)
        • Made of thin bone
        • Structure described as looking like honeycomb, “sandwich,” or foam
        • More air spaces towards rear compared to front of casque
      • Structure is fused to the neurocranium/skull (Richardson 1991)
    • Flexes from side-to-side (Crome and Moore 1988; Biggs 2013)
• Wattles present in Southern and Northern Cassowaries
  • Wattle (definition): long, hanging folds of skin of the foreneck
  • Southern Cassowary typically has two wattles (rarely one, sometimes three)
    • Variable in form
      • May be short or long
        • Up to 18 cm, or 7 in, in length
      • Usually a forked wattle on front of neck, but sometimes two, separated wattles on sides of neck
  • Northern Cassowary usually has one wattle (sometimes two wattles)
    • Yellow, red, or blue
    • Small and wart-like
  • Dwarf Cassowary has no wattle or a small wattle “nub”
• Brightly colored areas of delicate, bare skin in adults
  • Range of blues (from light to dark), turquoise, purple
  • Pink and red hindneck and wattles; also foreneck in Northern Cassowary
  • In some individuals, skin colors changes with the bird’s mood/level of excitement
• Brown or light brown eyes
  • Dull-yellow iris in Northern Cassowary
• Short, black bill
  • Laterally compressed (Rothschild 1900)
  • Can open its mouth very wide; able to swallow large food items (Coates 1985)

Legs and feet (adults)

• Long, thick, powerful gray-colored legs
• Large feet
• Both legs and feet covered with protective scutes (Davies 2002)
• Three toes
  • Inner toe with a long, sharp, dagger-like claw
    • Can inflict serious wounds

Differences in juveniles

• Small casque and wattles (develop with age)
• Dull bare parts
• Orange legs
• See Life Stages for description of chicks

(Coates 1985; Pratt and Beehler 2015; Folch et al. 2017a)

Adults

• Black, satin-like feathers on neck, body, and tail
• Plumage coarse and shaggy
• Helps with thermoregulation (Biggs 2013)
• Feathers loose, fluffy, hair-like; drooping
• Lack the barbicels (feather-connecting structures) that flying birds have (Davies 2002)

Juveniles

• Usually uniformly brown or orange-brown in color

Chicks (Folch et al. 2017a)

• Reddish-brown head and upper neck
• Upperparts of body creamy white, with broad dark brown stripes running from the chick’s lower neck towards its tail; stripes more narrow on thighs
• Often called "stripies" (Nicole LaGreco, personal communication 2017)
• Presumably disruptive coloration (to break up the outline/figure of the chick) (Pratt and Beehler 2015)
• Light colored abdomen, without bands

Unsual feathers

• Some flight feathers differ from other birds; have stout shafts, but no vanes, barbs, barbules (Andrew Mack, personal communication 2017)
• "V"-shaped feather caused by a main shaft and aftershaft of similar lengths; unusual, possibly unique to cassowaries (Andrew Mack, personal communication 2017)

Sexes similar-looking (Folch et al. 2017a; Folch et al. 2017b; Folch et al. 2017c, except as noted)

• To untrained observer, difficult to tell the sexes apart
• Females
• Bare parts said to be brighter (but cannot use this distinguish females from males; Pratt and Beehler 2015)
• Casque tends to be taller
• Wattle (hanging foreneck skin) longer
• Body size of mature females larger (Bentrupperbäumer 1997)
• Observed in Southern and Northern Cassoswaries
• Males
• Some male Southern Cassowaries with slightly longer tail feathers (about 20 cm, or 8 in, longer) (Bentrupperbäumer 1997)

Distinguishing the three cassowary species (Folch et al. 2017a, and where noted)

• Southern and Northern Cassowaries similar in body size; Dwarf Cassowary much smaller
• Southern Cassowary has most pronounced casque
• Casque of Northern Cassowary has a similar shape, but is sometimes brownish, greenish, or bluish, and not as curved; often with flattened areas on top (Andrew Mack, personal communication, 2017)
• Southern Cassowary has pronounced red wattles and more blue extending down the foreneck; blue skin between casque and eye
• Northern Cassowary has a large orange, red, yellow, or blue area on its lower foreneck (Pratt and Beehler 2015; Folch et al. 2017c)
• Northern Cassowary has pinkish longitudinal bands on bill (Folch et al. 2017c)
• Northern and Dwarf Cassowaries have a larger bulge on lower face than Southern Cassowary (Folch et al. 2017b; Folch et al. 2017c)
• Dwarf Cassowary has a dark face (with black and/or blue extending below eye) (Pratt and Beehler 2015; Andrew Mack, personal communication 2017)
• Some Southern Cassowaries may have black between the bill and eye
• Dwarf Cassowary foreneck feathering extends higher up than other two species; lacks a large, colored patch at the base of the foreneck (Folch et al. 2017b)
• Dwarf Cassowary casque is more low, black, and triangular than other two species (Folch et al. 2017b); wedge-shaped (Pratt and Beehler 2015)
• Dwarf Cassowary, C. b. westermanni (birds on Bird’s Head/Vogelkop), has a white patch near behind its eye

Digestion and excretion

• Short large intestine (Noble 1991; Webber and Woodrow 2004; Biggs 2013)
• Seeds pass through the digestive tract quickly and remain viable

Respiration

• Small lungs, relative to body size (Biggs 2013)

Resting

• Possess tendons that allow them to lie on the ground for extended periods (Biggs 2013)
• Not as developed in other ratites

Footprints (Marchant and Higgins 1990)

• Very large
• Three-toed
• Distinctive—used by scientists and hunters to detect cassowary presence

The Northern Cassowary has a large casque and (commonly) a single wattle.

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.

Like other ratites (emus, ostriches), cassowaries have loose, satin-like feathers on their neck, body, and tail.

Unlike the other two species, the Dwarf Cassowary have a black casque, black on their face, and no wattles (see Identification).

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.

Cassowaries have thick, powerful legs and feet.

Aside from fleeing danger, that dagger-like inner toe claw is their best defense.

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.