The Epitome of Bird Behavior; the Australian Bowerbirds: Part 2

by Graeme Guy | December 10, 2014

© Graeme GuyAs a nature photographer, I share the philosophy of Ofer Levy, who has written articles on this website, and spend time photographing subjects providing action or interesting behavior. The latter aspect is brilliantly exemplified by the courting activities of bowerbirds. In Part 1, I revealed the interesting behaviors and plumages of bowerbirds that build avenue-type bowers to attract females. Part 2 part focuses on bowerbirds that build maypole-like bowers as well as bowerbirds that don’t actually build bowers, but belong to that group based on DNA evidence. I also include links to two videos exemplifying some of the bowerbirds’ songs and calls.

Maypole builders

In the Atherton Tableland, at high altitudes, prototypical maypole builders Golden Bowerbirds (Prionodura newtonianus) can be found. This species is comparatively small compared with other bowerbirds but it builds the biggest bower. The male’s appearance, derived for display, is olive and bright gold (19) whereas the female, adapted to survival at the nest, is olive-backed with an ashy front and a yellow eye. The bower consists of two sticks or saplings joined sometimes by a fallen branch, which provides a display perch: a multitude of small sticks is assembled and glued with saliva around each of the upright poles. One pile of sticks is higher than the other and may be up to three meters in height and decorated with lichen, seed pods and yellow and white flowers (20). The male sings in the vicinity of the bower to attract a mate, the song is a rattling call flowed by a frog-like croak and forms of mimicry. Golden Bowerbird bowers are more embedded in darker forest, and action shots with current technology are not really possible. When the female appears in the vicinity, the behavior of the male immediately changes. He utters a different call and gathers a dried flower, (21) then places it in a specific location on the bower (22) (sound recorded by Marc Anderson). Then he performs his liquid gold fluttering flight. He then retires to a nearby perch to wait for the female to approach the bower. The nest, usually close to the bower, is a shallow cup in the cavity of a tree trunk or in the fork of a tree 2-3 meters high into which two plain, white eggs are laid.

Male golden bowerbird © Graeme Guy

19. Golden Bowerbird (male)

Large maypole-type bower of the golden bowerbird © Graeme Guy

20. The large maypole-type bower of the Golden Bowerbird

Golden bowerbird bringing flowers © Graeme Guy

21. Golden Bowerbird; bringing flowers for the lady

Flowers are placed in a specific place on the bower © Graeme Guy

22. Golden Bowerbird; the flowers are placed in a specific place on the bower

The no bower Bowerbirds

The Tooth-billed Bowerbird (Scenopooetes dentirostris) is confined, like the Golden Bowerbird to a pocket of North Eastern Queensland. It is relatively common in the remnants of rainforest around Lakes Barrine and Eachem. This stout-billed bowerbird has course brown streaks on the breast and abdomen over a background of light fawn (23). The large bill has a cutting tooth for collecting suitable leaves to decorate its bower (or more correctly a stage) (24). The song of this species is variable and vigorous in the vicinity of the stage, which makes the bird relatively easy to locate despite its camouflage colors. The stage consists of a cleared area on the forest floor about 2-3 meters in diameter. The male will then lay broad, green leaves, underside up around the cleared area. He will then position himself on various favorite branches in close proximity to his stage and sing loudly (listen to call recording). He is an excellent mimic and will give a good rendition of some other forest species including the Spotted Catbird. The male will tend his display several times a day, changing old leaves for new. Other than that he spends little time at ground level and will descend only when a female arrives at his stage. He will then advance in erratic hops, flicking his wings, erecting his tail and opening his beak.

Singing © Graeme Guy

Tooth-billed bowerbird clearning forest floor © Graeme Guy

24. Tooth-billed Bowerbird; the bower is constructed by clearing the forest floor and placing upturned leaves on the area.

Mitochondrial DNA testing has revealed that the Green and Spotted Catbirds (25) belong to the bowerbird family although, as their current behavior suggests, they diverged from the main grouping quite early in evolution. In contrast to the other bowerbirds they are monogamous and do not build a formal bower for courtship. Individuals have been observed to collect and place leaves in the manner of the Tooth-billed Bowerbird but these do not impact mating.

Spotted catbird © Graeme Guy

25. Spotted Catbird; a bowerbird with no bower but a distinctive meowing call

25. Spotted Catbird; a bowerbird with no bower but a distinctive meowing call

There is considerable debate on why there is a need for most members of this unique group of birds to build bowers. Displaying on the ground presents predation risks but it appears that bowerbirds have thrived in particular regions because of minimal risk from predators and an abundance of food that has freed the male from responsibilities of feeding his offspring. Bowers and their associated displays strongly influence mate choice by females and it appears that in line with survival of the fittest precepts that females will be drawn to an architect, a builder, an artist and a warrior. In other words, she selects the strongest, healthiest male who can design, maintain and defend his bower against rivals and is skillful enough to survive any modern-day predators that might come his way.

About the Author

Graeme was born and raised in the Wellington/Hutt Valley area of New Zealand. He practiced as a pharmacist in Dunedin, Napier and Hamilton after obtaining a degree in pharmacy. He later obtained a BSc and MSc (Hons) from Waikato University in Hamilton before completing a PhD in Biochemistry in Adelaide, Australia in 1982. After five years in Birmingham, U.K. he moved to Singapore where he became a Professor and Principal Investigator at the Institute of Molecular and Cell Biology in 1988. He is the author of over 100 scientific papers. Nature photography has always been an interest of Graeme's but became a serious pursuit for him in the last 15 years. He has won more than 1,200 awards in international exhibitions and has had a number of published articles and images, including 30 covers. In 2011, Graeme retired to live on Penang Island in Malaysia where the tropical environment provides him with plenty of photographic subjects. To learn more about Graeme and see more of his work, visit his website grguy.smugmug.com and blog malaysianwildlifephotography.blogspot.com.

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