Sensitivity to dimethyl sulphide suggests a mechanism for olfactory navigation by seabirds

Abstract

Petrels, albatrosses and other procellariiform seabirds have an excellent sense of smell, and routinely navigate over the world's oceans by mechanisms that are not well understood. These birds travel thousands of kilometres to forage on ephemeral prey patches at variable locations, yet they can quickly and efficiently find their way back to their nests on remote islands to provision chicks, even with magnetic senses experimentally disrupted. Over the seemingly featureless ocean environment, local emissions of scents released by phytoplankton reflect bathymetric features such as shelf breaks and seamounts. These features suggest an odour landscape that may provide birds with orientation cues. We have previously shown that concentrated experimental deployments of one such compound, dimethyl sulphide (DMS), attracts procellariiforms at sea, suggesting that some species can use it as a foraging cue. Here we present the first physiological demonstration that an Antarctic seabird can detect DMS at biogenic levels. We further show that birds can use DMS as an orientation cue in a non-foraging context within a concentration range that they might naturally encounter over the ocean.

Olfactory foraging in temperate waters: Sensitivity to dimethylsulfide by shearwaters in the Atlantic Ocean and Mediterranean Sea

“…To test whether the birds are able to detect and respond to DMS, we presented them with a binary choice between DMS and a control odour in a Y-maze at the colony, as other burrow-nesting petrel species significantly prefer the DMS arm in Y-mazes Nevitt and Bonadonna, 2005b). Then, to determine whether Cory's and Scopoli's shearwaters actually use this molecule in natural conditions, we also tested their response to DMS at sea.…”

“…Following the identification of DMS as an attractant and possible chemical cue (Nevitt et al, 1995), the sensitivity to this odorant has been evidenced for a number of petrel and non-petrel species of the Southern oceans through physiological and behavioural tests carried out at the colony Cunningham et al, 2008;Nevitt and Bonadonna, 2005b). No other tests, however, were performed under natural conditions at sea, except for one study on African penguins (Wright et al, 2011), nor under different ecological conditions.…”

Mesoscale fronts as foraging habitats: composite front mapping reveals oceanographic drivers of habitat use for a pelagic seabird

“…The ultimate mechanisms by which these features are located are not known, although a combination of memory effects, local enhancement [64] and colonies acting as information centres strongly influence observed foraging distributions in this species [52]. Proximate environmental factors enabling front detection include visual cues associated with the accumulation of foam and detritus [18,22]; flow patterns, including surface convergence [22] and cross-frontal jets [34], or olfactory cues such as dimethyl sulfide [65]. Persistent fronts probably produce a stronger surface signal than ephemeral features, increasing detectability.…”

Smelling Out Predators is Innate in Birds

“…Chemical cues appear to also be useful in the relationship between birds and their environment. For example, birds can use the sense of smell to discriminate aromatic plants (Petit et al 2002, Mennerat et al 2005, Gwinner & Berger 2008, to orientate and navigate , Wallraff 2004, Nevitt & Bonadonna 2005 and to forage (Hutchison & Wenzel 1980, Nevitt et al 1995, Marples & Roper 1996, Kelly & Marples 2004, Cunningham et al 2008. The role of olfaction for predation risk assessment remains barely explored in birds, although predator chemical cues could be useful in predator detection under low visibility conditions for many bird species.…”