Videographic evidence of endangered species depredation by feral cat.

Abstract

Feral cats (Felis catus) have long been implicated as nest predators of endangered ‘Ua‘u (Hawaiian Petrel; Pterodroma sandwichensis) on Hawai‘i Island, but until recently, visual confirmation has been limited by available technology. ‘Ua‘u nest out of view, deep inside small cavities, on alpine lava flows. During the breeding seasons of 2007 and 2008, we monitored known burrows within Hawai‘i Volcanoes National Park. Digital infrared video cameras assisted in determining the breeding behaviour and nesting success at the most isolated of burrows. With 7 cameras, we collected a total of 819 videos and 89 still photographs of adult and nestling ‘Ua‘u at 14 burrows. Videos also confirmed the presence of rats (Rattus spp.) at 2 burrows, ‘Ôma‘o (Myadestes obscurus) at 8 burrows, and feral cats at 6 burrows. A sequence of videos showed a feral cat taking a downy ‘Ua‘u chick from its burrow, representing the first direct evidence of ‘Ua‘u depredation by feral cat in Hawai‘i. This technique provides greater understanding of feral cat behaviour in ‘Ua’u colonies, which may assist in the development of more targeted management strategies to reduce nest predation on endangered insular bird species.

The effect of collar weight and capture frequency on bodyweight in feral cats (Felis catus)

“…Cats are primarily ambush predators, relying on a 'sit-and-wait' strategy that relies on stalking and camouflage (e.g. Judge et al 2012;Moseby and McGregor 2022); so, carrying the extra weight of a collar may not have a material impact.…”

A Tour de Force by Hawaii's Invasive Mammals: Establishment, Takeover, and Ecosystem Restoration through Eradication

“…Cats were reported to be abundant predators of native birds in forests of Lāna'i and O'ahu by the late 1800s (Rothschild 1893, Perkins 1903. Depredation of endangered bird species in Hawai'i has been frequently documented and attributed to cats (Hess et al 2007a), and recent photographic and videographic documentation confirms direct evidence (Judge et al 2012). However, the most compelling proof of the effects of feral cats on wildlife populations comes from examples where cats have been entirely removed from islands.…”

A Tour de Force by Hawaii’s Invasive Mammals: Establishment, Takeover, and Ecosystem Restoration through Eradication

“…Depredation of endangered bird species in Hawai'i has been frequently documented and attributed to cats based on the characteristic condition of carcasses Lindsey et al 2009;Judge et al 2012). Photographic or videographic documentation provides direct evidence that confirms depredation by cats (Judge et al 2012).…”

“…Depredation of endangered bird species in Hawai'i has been frequently documented and attributed to cats based on the characteristic condition of carcasses Lindsey et al 2009;Judge et al 2012). Photographic or videographic documentation provides direct evidence that confirms depredation by cats (Judge et al 2012). However, the most direct and compelling proof of the effects of feral cats on wildlife populations come from comparisons of areas with and without cats (Smith et al 2002) and examples where cats have been entirely removed from islands.…”