The design of experiments to investigate the combined effects of multiple stressors requires exposing target organisms to multiple combinations of stressor doses. Concurrent manipulation of stressors is often infeasible with wildlife, but long‐lasting health effects allow individual health to be used as an integrator of prior stressor exposure. The population of bottlenose dolphins in Barataria Bay, Louisiana, experienced long...

A 55+ year-long study of bottlenose dolphins ( Tursiops truncatus ) residing in Sarasota Bay on the west coast of Florida, USA, has supported the evolution of tags that address an expanding array of scientific questions while improving the welfare of tagged animals. Most individual dolphins from this community are identifiable from dorsal fin marks or freeze branding and are regularly resighted, which facilitates our ability t...

Studies of cetacean diving behavior in multiple locations in different ocean basins allow for an assessment of variability within and among populations. We examine foraging dive behaviors of goose‐beaked whales ( Ziphius cavirostris ) and dense‐beaked whales ( Mesoplodon densirostris ) using data from 132 tagged whales in seven locations in the Pacific and Atlantic Oceans and the Mediterranean Sea. Acoustic recording tags are...

Common bottlenose dolphins ( Tursiops truncatus ) produce individually distinctive signature whistles that are learned early in life and that help animals recognize and maintain contact with conspecifics. Signature whistles are the predominant whistle type produced when animals are isolated from conspecifics. Health assessments of dolphins in Sarasota, Florida (USA) provide a unique opportunity to record signature whistles, as...

Stemming from the traditional use of field observers to score states and events, the study of animal behaviour often relies on analyses of discrete behavioural categories. Many studies of acoustic communication record sequences of animal sounds, classify vocalizations, and then examine how call categories are used relative to behavioural states and events. However, acoustic parameters can also convey information independent of...

Auditory masking by anthropogenic noise may impact marine mammals relying on sound for important life functions, including echolocation. Animals have evolved antimasking strategies, but they may not be completely effective or cost‐free. We formulated seven a priori hypotheses on how odontocete echolocation behavior could indicate masking. We addressed six of them using data from 15 tagged sperm whales subject to experimental e...

Auditory neuroscience in dolphins has largely focused on auditory brainstem responses; however, such measures reveal little about the cognitive processes dolphins employ during echolocation and acoustic communication. The few previous studies of mid- and long-latency auditory-evoked potentials (AEPs) in dolphins report different latencies, polarities, and magnitudes. These inconsistencies may be due to any number of difference...

There is substantial geographic variation in the behavior and social structure of sperm whales worldwide. The population in the Eastern Caribbean is thought to be isolated from other areas in the North Atlantic. We describe the behavior and social structure of the sperm whales identified off Dominica during an eight year study (2005–2012; 92% of photographic identifications) with supplementary data collected from seven other o...

Ramp‐up or soft‐start procedures (i.e., gradual increase in the source level) are used to mitigate the effect of sonar sound on marine mammals, although no one to date has tested whether ramp‐up procedures are effective at reducing the effect of sound on marine mammals. We investigated the effectiveness of ramp‐up procedures in reducing the area within which changes in hearing thresholds can occur. We modeled the level of soun...

Increasing evidence links exposure to Navy sonar with certain mass stranding events of deep diving beaked whales. Although the cause of these strandings is unknown, one theory suggests that the animals confuse the sonar signals with vocalizations of killer whales, a known predator. Here we analyze the movement patterns of a tagged female Blainville's beaked whale in reaction to playback of killer whale predation calls. During...

In 2007 and 2008, controlled exposure experiments were performed in the Bahamas to study behavioral responses to simulated mid‐frequency active sonar (MFA) by three groups of odontocetes: false killer whales, Pseudorca crassidens ; short‐finned pilot whales, Globicephala macrorhynchus ; and melon‐headed whales, Peponocephala electra . An individual in each group was tagged with a Dtag to record acoustic and movement data. Duri...

Four short‐finned pilot whales, Globicephala macrorhynchus , were tagged with digital acoustic recording tags (DTAGs) for a total of 30 h in the Bahamas during 2007. Spectrograms were made of all audible sounds, which were independently categorized by three observers. Of 4,098 calls, 1,737 (42%) were placed into 173 call types, which were defined as calls that occurred more than once. Of the 173 call types, 51 contained at lea...

Long‐term passive acoustic monitoring of marine mammals on navy ranges provides the opportunity to better understand the potential impact of sonar on populations. The navy range in Tongue of the Ocean (TOTO), Bahamas contains extensive hydrophone arrays, potentially allowing estimation of the density of deep diving, vocally active species such as the sperm whale ( Physeter macrocephalus ). Previous visual surveys in TOTO have...

Communicating animals must balance fitness benefits against the costs of signaling, such as increased predation risk. Cetaceans communicate mainly with sound and near‐surface vocalizations can place signalers at risk from shallow‐diving top‐predators with acute hearing such as killer whales. Beaked whales are deep divers living in small cohesive groups with little social defense from predation. Little if anything is known abou...

Despite much research on bottlenose dolphin signature whistles, few have investigated the role of maternal whistles in early calf development. We investigated maternal whistle use in the first weeks postpartum for captive dolphins. The overall whistling rate increased by a factor of ten when the calves were born and then decreased again in the third week of the one surviving calf. Adult whistles were distinguished from calf wh...

Marine mammal social interactions are poorly understood primarily because of the difficulty of observing these behaviors in the wild. Observations of copulations in North Atlantic right whale surface active groups (SAGs) have led to the hypothesis that the function of these groups is for conception. The occurrence and composition of SAGs sighted from 1992 to 2001 were investigated on the basis of age, sex, and reproductive sta...

The impact of naval sonar on beaked whales is of increasing concern. In recent years the presence of gas and fat embolism consistent with decompression sickness (DCS) has been reported through postmortem analyses on beaked whales that stranded in connection with naval sonar exercises. In the present study, we use basic principles of diving physiology to model nitrogen tension and bubble growth in several tissue compartments du...