Natural history of the Long-whiskered Owlet

By Kathi Borgmann
Long-whiskered Owlet

Long-whiskered Owlet Xenoglaux loweryi

  • Amazonas, Peru

In 1976, Louisiana State University researchers from the Museum of Natural Science working in the remote mountains of northern Peru made one of the great ornithological discoveries of the past 50 years—a new species of owl unlike any other. Scientists and birders alike were stunned when O’Neill and Graves (1977) showed the world a tiny bird not much bigger than a House Finch with spectacular long “whiskers” and deep red eyes. The owl was so different from any other species of owl that they described an entire new genus for it––Xenoglaux, or “strange little owl.”

Then the Long-whiskered Owlet disappeared for 24 years, cementing it in birding legend. It wasn’t until 2002 when a survey conducted by Louisiana State University Museum of Natural Science and the Museo de Historia Natural de la Universidad Nacional de San Marcos found more Long-whiskered Owlets and documented its voice for the first time. But little was known about its natural history, and finding the species rapidly became one of the Holy Grails of Neotropical birding. An additional six years passed before birders finally figured out how to find the owlet in the moss-shrouded cloud forests around Abra Patricia, largely thanks to these first recordings.

Since the 2002 expedition Daniel Lane, a research associate at Louisiana State University and Fernando Angulo, a researcher at CORBIDI sought to learn more about its natural history—its vocalization, habitats, and distribution. They recently published their findings in The Wilson Journal of Ornithology and archived their sound recordings at the Macaulay Library.

According to surveys conducted by Lane and Angulo, Long-whiskered Owlets occur from around 1,900 m to 2,600 m (6,200–8,500 feet) in the Abra Patricia and Colán mountain ranges in northern Peru. Previously the owlets were thought to occupy stunted forests, but Lane and Angulo found them in forests with trees less than 9 m (29 feet) tall and in taller forests up to 15 m (49 feet) tall both with and without bamboo in the understory. In these forests, Long-whiskered Owlets primarily eat insects but may eat small frogs or lizards on occasion.

Long-whiskered Owlet Xenoglaux loweryi

  • San Martín, Peru

As with most nocturnal species, vocalizations played an important role in finding and studying the owlet. Starting with the first known recordings of the species on the 2002 expedition, Lane and Angulo documented the Long-whiskered Owlet’s vocal repertoire. Lane recorded a single wavering “whooo” (ML534789), which he archived in the Macaulay Library. Later Angulo recorded its rarely given call—a fast guttural trill (ML28125101). The owlet appears to sing shortly after dusk with an occasional night song. Several of their owlet recordings have been archived in the Macaulay Library providing Lane and Angulo with a permanent record.

Long-whiskered Owlet Xenoglaux loweryi

  • Amazonas, Peru

Based on the number of locations where Lane and Angulo found the Long-whiskered Owlet they suggest that the owlet should be downgraded to Vulnerable status on the International Union for the Conservation of Nature’s (IUCN) Red List of Threatened Species. Despite forest loss nearby, Lane and Angulo are optimistic that the Long-whiskered Owlet will be protected in existing reserves and by the inaccessible nature of its habitat.

Listen to more recordings and see more photos of the Long-whiskered Owlet at the Macaulay Library, your wildlife media archive.

Lane, D. F., and F. Angulo (2018). The distribution, natural history, and status of the Long-whiskered Owlet (Xenoglaux loweryi). The Wilson Journal of Ornithology 130:650–657.

O’Neill, J. P., and G. R. Graves (1977). A new genus and species of owl (Aves: Strigidae) from Peru. Auk 94:409­–416.