Estimating relative energetic costs of human disturbance to killer whales (Orcinus orca)

Changes in bottlenose dolphin whistle parameters related to vessel presence, surface behaviour and group composition

“…This study suggests that the acoustic parameters of whistle vocalizations vary naturally according to behavioural context and group composition, but are also influenced by tour boat presence and engine noise. The vocalization changes we observed in the presence of one or more tour boats could have a long-term, negative influence on the bottlenose dolphin population in Walvis Bay if they reduce the communication range of whistles (Jensen et al, 2009), result in increased energy expenditure (Holt, Noren, Dunkin, & Williams, 2015;Williams et al, 2006) or elevate stress levels (Rolland et al, 2012;Romano et al, 2004). Such effects would be compounded if combined with other behavioural responses to tour boat presence that increase energy expenditure, for example increased socializing or travelling (Indurkhya, 2012).…”

“…Short-term impacts associated with boat interactions include group directional changes (Steckenreuter, Möller, & Harcourt, 2012;, changes in group dispersion (Arcangeli & Crosti, 2009;Steckenreuter et al, 2012), heightened breathing synchrony (Hastie, Wilson, Tufft, & Thompson, 2003), increased dive times (Lusseau, 2003b) and changes in vocalizations (Buckstaff, 2004;Scarpaci, Bigger, Corkeron, & Nugegoda, 2000). Such changes can have longer lasting impacts resulting in seasonal (Rako et al, 2013) or long-term (Bejder et al, 2006) displacement and increased energy expenditure (Williams, Lusseau, & Hammond, 2006).…”

“…Although excessive noise can cause hearing damage, and even strandings in cetaceans (Weilgart, 2007), the more relevant impacts of boat noise generated through marine tourism activities are likely to be the masking of calls (Jensen et al, 2009) or biological cues (Clark et al, 2009), behavioural changes (Williams et al, 2006) or displacement (Rako et al, 2013), and stress (Rolland et al, 2012). Animals can adjust their acoustic signalling behaviour to respond to increases in noise in several different ways, which are not necessarily mutually exclusive.…”

Best Practice Framework and Principles for Monitoring the Effect of Coastal Development on Marine Mammals

“…Third, and worst, is the recent extinction of the Baiji (Lipotes vexillifer) throughout its range (Turvey et al, 2007). Each of these declines has been directly attributed to cumulative pressures from industrial activities and the exposure to threats associated with fisheries interactions, reduction in prey availability, increases in vessel traffic, pollution (including noise) loads and construction activities along with habitat degradation and habitat reduction (Ross, 2006;Wang et al, 2006Wang et al, , 2007Williams et al, 2006;Turvey et al, 2007;Reeves et al, 2008;Lusseau et al, 2009;Williams and O'Hara, 2010).…”

Oh, Behave: When Wildlife Behavior Matters in Conservation

“…For instance, a wary animal avoiding encounters with humans must budget more time to energetically expensive activities such as travelling and vigilance, which detracts from time spent on other necessary activities, such as searching for food or mates and raising young (Frid and Dill 2002;Beale 2007;Stankowich 2008). In fact, killer whales (Orcinus orca) significantly reduce their foraging time in the presence of boats (Williams, Lusseau, and Hammond 2006;Lusseau et al 2009), and Amur tigers (Panthera tigris altaica) spend less time at kills and consume less meat when disturbed by humans (Kerley et al 2002). Although these changes in energetic budgets may seem temporary and of little impact, when they occur frequently they can affect the survival and reproduction of individuals, as well as the effective population size of species (Anthony and Blumstein 2000).…”