Beautiful Sunbird (Cinnyris pulchellus) Fact Sheet: Physical Characteristics

Morphometrics

Data source: Cheke et al. (2001), p. 283. Range values provided here; see Cheke et al. (2001) for means, standard deviations, and sample sizes.

* Attribute measurements for this group not provided in Cheke et al. (2001).

** Sample size ≤ 3 individuals.

Note on mass: Male C.p. pulchellus significantly heavier than females (Cheke et al. 2001).

Notes on length measurements given by Cheke et al. (2001)

• Wing: maximum chord method for folded wing, by which the curvatures of the wing are eliminated
• Tail: from the tip of the longest tail feather to the point where the feathers join the body
• Bill: from tip of bill to skull
• Tarsus: from the depression at the base of its rear joint to the end of the last scale before the toes separate at the front

Body and wings (Winkler et al. 2015, and as noted)

• Small, compact body
  • Cylindrical, ovoid shape
• Medium-length, rounded wings
• 10 primaries (long flight feathers on wings) [sunbirds, general] (Cheke and Mann 2008)
• 12 rectrices (tail feathers that control direction during flight) [sunbirds, general] (Cheke and Mann 2008)
  • Central tail feathers (rectrices) elongated in breeding males (called "streamers")

Head

• Eyes
  • Black or very dark brown (Cheke et al. 2001)
• Bill (Cheke and Mann 2008; Elphick 2014)
  • Black
  • Long, slender, decurved
    • Adapted to fit the tubes of certain flowers
  • Sharply pointed
  • Fine serrations near the tip
  • External nostrils
    • In groove
    • Flaps (opercula) prevent pollen from clogging nostrils
• Tongue
  • Long and narrow (Cheke and Mann 2008)
  • Tubular: Sides curve inwards to form two tubes (Cheke et al. 2001)
  • Divided at tip (Elphick 2014)
  • Fringe along tongue tip
    • Helps sunbird ingest nectar by capillary action (Cheke and Mann 2008; Elphick 2014)
  • Two grooves in palate help draw nectar into bill (Cheke and Mann 2008)

Legs and feet

• Legs
  • Black (Cheke et al. 2001)
• Feet
  • Black (Cheke et al. 2001)
• Toes (Elphick 2014)
  • Short
  • Strong
  • End in fine, sharp claws

C. p. pulchellus

• Adult males, breeding (Fry et al. 2000; Cheke et al. 2001; Stevenson and Fanshawe 2002; Cheke and Mann 2008; Sinclair and Ryan 2010; Borrow and Demey 2014)
  • Glossy green plumage
    • Abdomen and sides of body metallic green
    • Sometimes a pinkish or golden sheen
    • Some with vibrant blue feathers
  • Broad, red breast bordered by yellow side patches
    • Bordered above by a narrow blue band
    • Makes C. pulchellus part of the “double-collared sunbird” group in Cinnyris
  • Wing coverts and flight feathers blackish or dark brown
  • Tail bluish-black
    • Tail streamers up to 6 cm long (see Sexual Dimorphism)
    • Some metallic green edging on tail streamers
  • C. p. melanogastrus has black belly
• Adult males, non-breeding (Cheke et al. 2001, and as noted)
  • Molt into duller, female-like plumage after breeding
  • Gray-brown above, dusky yellow below
  • May retain black tail streamers, primary and secondary wing feathers
    • Some individuals retain tail streamers (first year birds?), others do not (Cheke et al. 2001; Cheke and Mann 2008)
  • Retain green shoulders
  • May retain green chin or may become a whitish throat patch
  • Otherwise, similar to female (Fry et al. 2000)
• Adult female (Cheke et al. 2001; Cheke and Mann 2008)
  • Plumage dull; no metallic feathers
  • Pale ashy-olive, brown-olive, or dull brown above, yellow-tinged
  • Darker brown on wings and tail
  • Tail blackish-brown with slight blue or bronze-green gloss
  • Pale yellow or white stripe behind eye
  • Chin and throat whitish
  • Pale yellow below
  • Underwing dark brown
• Juvenile/immature (Fry et al. 2000; Cheke et al. 2001; Stevenson and Fanshawe 2002; Cheke and Mann 2008)
  • Similar appearance to adult female
  • Throat and upper chest black-to-dusky grey, bordered by creamy-white moustache stripes
  • Immature male develops green on throat and lesser coverts with age
  • Underparts dull
• No intermediate plumage stage, as in some other sunbirds species (Cheke and Mann 2008)

C. p. melanogastrus

• Males (Cheke et al. 2001)
  • Abdomen is black instead of metallic green
  • Red patch larger
  • Undertail coverts with metallic green-blue tips
  • Shorter central tail feathers (28-45 mm)
• Females (Cheke et al. 2001)
  • Less blackish throat
  • More dusky streaking below

Molting (Cheke et al. 2001)

• Some males molt long tail
• Other males do not (first year birds?)
  • Molt body feathers twice per year
  • May molt wings and tail only once a year, at start of breeding season
    • Combination of new, duller body plumage and well-worn tail streamers and wing feathers after breeding
• Non-breeding plumage sometimes omitted in equatorial regions

Sexual dichromatism (Cheke and Mann 2008)

• Differences in color tone and presence/absence of iridescence between males and females (Cheke and Mann 2008)
• Males brighter than females, especially during breeding (Cheke and Mann 2008)
• See Plumage, above

Long tails in males (Cheke and Mann 2008)

• Males: elongated central tail feathers (rectrices)
  • Also casually referred to as “streamers”
  • Up to 6 cm long
• Females: no long tail
• See Plumage, above

Body size

• Males can be larger than females (Cheke and Mann 2008)
• See Physical Characteristics, above

Similar species (Cheke et al. 2001; Sinclair and Ryan 2010)

• Black-bellied Sunbird, Cinnyris nectarinoides
• Congo Sunbird, Cinnyris congensis
• Copper Sunbird, Cinnyris cupreus
• Nile Valley Sunbird, Hedydipna metallica
• Pygmy Sunbird, Hedydipna platura
• Shining Sunbird, Cinnyris habessinicus
• Variable Sunbird, Cinnyris venustus

For images, visit The Internet Bird Collection.

Digestion and excretion

• No digestive crop for food/nectar storage [sunbirds, general] (Cheke and Mann 2008)
• Parts of digestive tract (lumen, proventriculus) thickened in Cinnyris spp.
• Helps digest solid foods (Cheke and Mann 2008)
• May indicate a varied diet of arthropods/insects and fruit as well as nectar
• Efficient kidneys for diluting urine [White-bellied Sunbird] (Purchase et al. 2013)
• Can also concentrate urine when ingesting a lot of salt
• Combined nectar and arthropod-based diet may help maintain electrolyte balance

Thermoregulation

• Some sunbirds roost together to cope with cold nights [sunbirds, general] (Cheke and Mann 2008)

Breeding plumage of an adult male Beautiful Sunbird, Cinnyris pulchellus.

Adult males are distinguished by a red breast band, bordered by yellow on each side, and iridescent green plumage. This male's 'tail streamers' (elongated tail feathers) extend beyond the edge of the photograph.

Image credit: © Isidro Vila Verde at Flickr. All rights reserved. Used with permission from the artist.

Image details: Taken 01 August 2007 in Gambia.

Plumage of a juvenile Beautiful Sunbird, Cinnyris pulchellus.

This duller plumage helps younger males and adult females, which have similar coloration, be less conspicuous.

Image credit: © Isidro Vila Verde at Flickr. All rights reserved. Used with permission from the artist.

Image details: Taken 29 April 2008 in Gambia.