Giant petrels as predators of albatross chicks

Abstract

Giant petrels Macronectes spp. are not thought to be important predators of albatross chicks, although they are known to kill pre-fledging Thalassarche and Phoebetria albatrosses. We report the first records of predation of healthy great albatross Diomedea spp. chicks, killing wandering albatrosses D. exulans at night on sub-Antarctic Marion Island. Breeding success of this species has decreased markedly in the area where attacks occurred, suggesting that giant petrel predation events are a recent phenomenon. Mouse attacks on wandering albatross chicks may have contributed to the development of this hunting technique. We also report the first observations of giant petrel predation on pre-fledging grey-headed albatross T. chrysostoma chicks as well as additional records of sooty albatross P. fusca chicks being targeted. Only adult northern giant petrels M. halli have been confirmed to kill albatross chicks on Marion Island. Given the threatened status of wandering albatrosses, and the importance of Marion Island for this species, monitoring of their breeding success is necessary to assess whether the predation of chicks by giant petrels spreads around the island.

Trends and tactics of mouse predation on Tristan Albatross Diomedea dabbenena chicks at Gough Island, South Atlantic Ocean

“…The cause of these wounds was confirmed by filming the nests with motion-activated trap cameras (Bushnell Trophy Camera, model 119436) that recorded nocturnal activity with infra-red images. The infra-red flash does not deter predators and these cameras have been used to record Northern Giant Petrels Macronectes halli predating on Wandering Albatross Diomedea exulans chicks on Marion Island (Dilley et al 2013). Cameras were mounted 30 cm above the ground on PVC poles, 4-5 m from the nest, and set on high motion sensitivity to take one image second -1 for 3 seconds upon activation.…”

A high‐resolution panorama camera system for monitoring colony‐wide seabird nesting behaviour

“…Dilley et al . ), document presence of predators and even the frequency of spatially rare events (e.g. Forster & Phillips ).…”

“…Gaston et al 2014), the timing of breeding failures (e.g. Dilley et al 2013), document presence of predators and even the frequency of spatially rare events (e.g. Forster & Phillips 2009).…”

“…Land‐based cameras (Dilley et al . ) or those fixed onto animals (Sakamoto et al . ) can track behaviour but wider scale perspectives suffer as data tends to be collected at the scale of individual, pairs or small groups of animals.…”

“…Land-based cameras (Dilley et al 2013) or those fixed onto animals (Sakamoto et al 2009) can track behaviour but wider scale perspectives suffer as data tends to be collected at the scale of individual, pairs or small groups of animals. To improve replication, fleets of remote cameras can be used (Newbery & Southwell 2009) or multiple images stitched together post hoc to form a montage (Poncet et al 2006); however, this increases cost, either for hardware or labour to manually construct panoramas.…”