Nyctibiidae: Potoos

Northern Potoo.  © Francisco Alba

The potoos are an extraordinary group of Neotropical night birds that spend most of their daylight hours masquerading as broken branches.  They have cryptic plumage that enables them to hide in plain sight, elongating and stiffening their bodies into a “freeze” position that they maintain for extended periods.

In their alert posture, potoos take on a bizarre, cartoonish appearance.  Their heads appear implausibly large, dominated by an enormous Cheshire grin and the predatory leer of shiny glass spheres.  They sometimes look less like birds than like greedy, disheveled, googly-eyed monsters conjured from the imagination of Maurice Sendak to inspire childhood nightmares and supernatural folklore.

Northern Potoo.  © Rancho las Palomas

Potoos strongly resemble the frogmouths (Podargidae) of tropical Asia and Australia, which may be their closest relatives—although this question remains unresolved.  Both groups have outsized heads and huge gaping mouths that are ideal for capturing the largest of tropical insects.  Potoos have also been known to accommodate small birds and bats in theirs.

Potoos’ large eyes must enhance their light-gathering capacity for effective night vision and hunting.  The size of their eyes may also support their daytime camouflage strategy, as their eyelids are modified to let some light through when closed, so large lenses may allow potoos to monitor their surroundings during the day without disrupting their camouflage.

Taxonomy

The internal taxonomy of the Nyctibiidae is mostly settled, with seven species recognized.  Common and Northern Potoos are essentially indistinguishable by sight, and were long regarded as conspecific, but their voices are entirely different.  The mainland and West Indian subspecies of Northern Potoo seem inherently likely to be distinct forms or multiple species based on their geographical separation, but they lack clear, consistent differences in voice or appearance.

Great Potoo (Nyctibius grandis)

Long-tailed Potoo (Nyctibius aethereus)

Northern Potoo (Nyctibius jamaicensis)

Common Potoo (Nyctibius griseus)

Andean Potoo (Nyctibius maculosus)

White-winged Potoo (Nyctibius leucopterus)

Rufous Potoo (Nyctibius bracteatus)

References

Cleere, N., and D. Nurney. 1998. Nightjars: A Guide to Nightjars and Related Nightbirds. Pica Press, Sussex.

Gu, D., R.A. Behrstock, and T.S. Schulenberg. 2014. Northern Potoo (Nyctibius jamaicensis), version 1.0. In Neotropical Birds Online (T.S. Schulenberg, ed.). Cornell Lab of Ornithology, Ithaca, N.Y. https://doi.org/10.2173/nb.norpot1.01.

Roberson, D. 2015. Bird Families of the World: Potooos, Nyctibiidae, http://creagrus.home.montereybay.com/potoos.html. (Posted December 16, 2015. Accessed October 28, 2017.)