Adam A. Pack

• PhD
• Professor (Full) at University of Hawaii at Hilo

Anthropogenic impacts on marine systems are increasing in frequency, geographic range and severity. While changes in climate will likely lead to the greatest impacts at the system-level, for marine megafauna, entanglement in marine debris also constitutes a pernicious threat. For baleen whales, in regions where high productivity and prolific fisher...

The juvenile period is an important stage of growth and development across animals, often consisting of graded stages of physical and social development. For cetaceans, locomotor and social development are key to survival after weaning; individuals require dive capabilities for successful foraging and navigating their aquatic habitat as well as rob...

Birds use sound for conspecific communication. According to the acoustic niche hypothesis, they avoid signal competition with other species by partitioning sound in frequency and time. Others have observed introduced species changing the vocal behavior of native species; however, community-level effects of multiple introduced species remain unknown...

Humpback whale song chorusing dominates the marine soundscape in Hawai‘i during winter months, yet little is known about spatio-temporal habitat use patterns of singers. We analysed passive acoustic monitoring data from five sites off Maui and found that ambient noise levels associated with song chorusing decreased during daytime hours nearshore bu...

Abstract After decades of population growth, the central stock of the North Pacific population of humpback whales, known as the Hawaiʻi Distinct Population Segment (HDPS), was delisted from its endangered status in 2016. At that time, however, an unprecedented heating event, the Pacific Marine Heatwave (PMH) was already underway. The PMH coincided...

Acoustic communication in the form of songs is a learned behavior in oscine that can be passed down from one generation to the next through cultural transmission. Over time songs can change when populations become isolated from one another, creating dialects that are distinct to a population. Habitat fragmentation is an isolating mechanism that can...

After decades of population growth, the central stock of the North Pacific population of humpback whales, known as the Hawai’i Distinct Population Segment (HDPS), was delisted from its endangered status in 2016. At that time, however, an unprecedented heating event, the “Pacific Marine Heatwave” (PMH) was already underway. The PMH coincided with re...

Humpback whales (Megaptera novaeangliae) are exceptionally vocal among baleen whale species. While extensive research has been conducted on humpback whale songs, gaps remain in our understanding of other forms of communication, particularly non-song calls. Here, we compare the spectral features and temporal parameters of non-song calls recorded fro...

Studies of humpback whale (Megaptera novaeangliae) habitat use in their Hawaiian breeding grounds have revealed that mother‐calf pairs favor shallow waters to avoid harassment from males. However, human activity in these same waters may exert an opposing force on habitat use. To investigate this hypothesis, instantaneous scan samples of whale and v...

Passive acoustic monitoring (PAM) with autonomous bottom-moored recorders is widely used to study cetacean occurrence, distribution and behaviors, as it is less affected by factors that limit other observation methods (e.g., vessel, land and aerial-based surveys) such as inclement weather, sighting conditions, or remoteness of study sites. During t...

Bio-logging devices are advancing the understanding of marine animal behavior, but linking sound production and behavior of individual baleen whales is still unreliable. Tag placement potentially within the near field of the sound source creates uncertainty about how tagged animal sounds will register on recorders. This study used data from a tagge...

Understanding reproductive profiles and timing of reproductive events is essential in the management and conservation of humpback whales (Megaptera novaeangliae). Yet compared to other parameters and life history traits, such as abundance, migratory trends, reproductive rates, behavior and communication, relatively little is known about variations...

Little is known about how important social behaviors such as song vary within and among populations for any of the endemic Hawaiian honeycreepers. Habitat loss and non-native diseases (e.g., avian malaria) have resulted in isolation and fragmentation of Hawaiian honeycreepers within primarily high elevation forests. In this study, we examined how i...

We investigated whether calf age and calf size influence habitat choice by humpback whale mother-calf pairs in their breeding grounds. During 1997-2008, we conducted focal follows of mother-calf pairs in Hawaiian waters. Tail-fluke identification photographs and calf lengths (measured through videogrammetry) were obtained. Water depth and sea-bed t...

Over the last 20 years, significant habitat shifts have been documented in some populations of cetaceans. On Little Bahama Bank (LBB) there are sympatric communities of resident Atlantic spotted dolphins (Stenella frontalis) and bottlenose dolphins (Tursiops truncatus), monitored since 1985. The size and social structure (three clusters: Northern,...

Supplemental file for hierarchical cluster. Analysis and nMDS for 2013 to 2015 on Great Bahama Bank (GBB). (XLSX)

Scatter plot of year versus annual anomalies in sea surface temperature (°C) for the combined shallow and adjacent deep-water areas on Little Bahama Bank and Great Bahama Bank from 1998–2012. (DOCX)

Scatter plot of year versus annual anomalies in sea surface temperature (°C) on and off Little Bahama Bank from 1998–2012. (DOCX)

Scatter plot of year versus annual anomalies in surface winds on and off Little Bahama Bank from 1998–2012. (DOCX)

Association matrix for hierarchical cluster. Analysis and nMDS for 2013 to 2015 on Great Bahama Bank (GBB). (XLSX)

Scatter plot of year versus annual anomalies in surface winds for the combined shallow and adjacent deep-water areas of Little Bahama Bank and of Great Bahama Bank from 1998–2012. (DOCX)

Scatter plot of year versus annual anomalies in surface winds on and off Great Bahama Bank from 1998–2012. (DOCX)

Scatter plot of year versus annual anomalies in surface chlorophyll A production for the combined shallow and adjacent deep-water areas on Little Bahama Bank (LBB) and on Great Bahama Bank (GBB) from 1998–2012. (DOCX)

Scatter plot of year versus annual anomalies in surface chlorophyll A production on and off Little Bahama Bank from 1998–2012. (DOCX)

The critically endangered Hawaiian Crow or ′Alalā (Corvus hawaiiensis) is currently extinct in the wild and the remaining 115 individuals are being captively managed on Hawai′i and Maui Islands by the Zoological Society of San Diego. Here we provide the first comprehensive analysis of the vocal repertoire of this species. We documented the vocal re...

For most avian species, social behaviour is critically important for survival and reproductive success. Many social behaviours in birds are culturally transmitted, and as bird populations decline across the globe, important elements of these behaviours may be lost. The Hawaiian crow or 'alalā, Corvus hawaiiensis, is a socially complex avian species...

It has been hypothesized that protecting herbivorous fishes within Marine Reserves (MRs) will help these areas to resist algal overgrowth of corals. However, we lack empirical studies demonstrating the validity of key assumptions underpinning this concept, including that herbivorous fishes (1) are permanently resident within MR boundaries, (2) rout...

Male humpback whales produce loud “songs” on the wintering grounds and some sing while escorting mother–calf pairs, exposing them to near-continuous sounds at close proximity. An Acousonde acoustic and movement recording tag deployed on a calf off Maui, Hawaii captured sounds produced by a singing male escort. Root-mean-square received levels range...

Humpback whale calves in the winter breeding grounds vocalize and the spectral characteristics of some of these vocalizations have been described, but sound levels of calf vocalizations have not been investigated. There is also a lack of general information on vocalizations from mothers. To address these issues, we deployed suction cup acoustic and...

There is increasing concern over the potential ecological effects from high levels of oceanographic anthropogenic noise on marine mammals. Current US NOAA regulations on received noise levels as well as the Draft Guidance for Assessing the Effect of Anthropogenic Sound on Marine Mammals are based on limited studies conducted on few species. For the...

Microbes are now well regarded for their important role in mammalian health. The microbiology of skin - a unique interface between the host and environment - is a major research focus in human health and skin disorders, but is less explored in other mammals. Here, we report on a cross-population study of the skin-associated bacterial community of h...

Humpback whales congregate annually in low-latitude winter breeding and calving grounds. While on these grounds, females with a dependent calf ('maternal females') are sometimes closely at-tended by one or more male escorts. Using data collected from a shore-based observation platform in the Hawaiian Islands, we tested the hypothesis that the spati...

While on their winter breeding grounds, male humpback whales (Megaptera novaeangliae) produce long sequences of structured vocalizations called song, whose function within the mating system is still unresolved. Here we ask which males sing. Is it only those sexually mature, as typifies songbirds and some lekking ungulates in which vocalizations dur...

Injury from collisions with vessels is a growing threat worldwide for many species of whales. Thirty seven years of historical records were examined for evidence of vessel collisions with humpback whales in the main Hawaiian Islands. Between 1975 and 2011, 68 collisions between vessels and whales were reported including 59 witnessed collisions and...

Assortative pairing, and its relation to mate choice, has rarely been documented in mammals. Using data collected during 1998–2007, we investigated size-assortative pairing as it relates to discrimination amongst potential mates in humpback whale, Megaptera novaeangliae, dyads in the Hawaiian breeding grounds. Across 67 male–female dyads in which b...

Predictive habitat models can provide critical information that is necessary in many conservation applications. Using Maximum Entropy modeling, we characterized habitat relationships and generated spatial predictions of spinner dolphin (Stenella longirostris) resting habitat in the main Hawaiian Islands. Spinner dolphins in Hawai'i exhibit predicta...

Humpback whale song research has focused on analyzing the full song structure rarely describing individual song units. Even less progress has been made in automatically distinguishing and classifying these individual units. Two different techniques were employed to study their call units, visual/aural and automated/statistical. Humpback whale songs...

Since 1985, a well-studied community of free ranging Atlantic spotted dolphins, Stenella frontalis, and bottlenose dolphins, Tursiops truncatus, has been observed underwater in the Bahamas. Over this period, the dolphins have become habituated to human swimmers. Long-term underwater observations revealed that some of these dolphins engaged in play...

Humpback whales produce songs which consist of a sequence of short, continuous sounds known as units. This paper introduces an automated algorithm to extract the unit contours. An unsupervised classification is developed to provide a set of distinct units of the singing group. The analysis is performed on the vocalization spectrograms, which are no...

Humpback whales, Megaptera novaeangliae, are one of the most recognizable and investigated marine mammals. However, little progress has been made in automatically distinguishing and classifying individual units of their song. A Matlab script has been developed to characterize the different song units and to apply the appropriate statistics to separ...

Humpback whales, unlike most mammalian species, learn new songs as adults. Populations of singers progressively and collectively change the sounds and patterns within their songs throughout their lives and across generations. In this study, humpback whale songs recorded in Hawaii from 1985 to 1995 were analyzed using self-organizing maps (SOMs) to...

Invasive tags designed to provide information on animal movements through radio or satellite monitoring have tremendous potential for the study of whales and other cetaceans. However, to date there have been no published studies on the survival of tagged animals over periods of years or decades. Researchers from the National Marine Mammal Laborator...

From a database of approximately 5,000 Hawaiian humpback whales identified photographically between 1976 and 2010, we extracted 71 males and 39 females having resighting spans of 10 or more years, from first to most recent sighting. Findings included: (1) the male-biased sex ratio was like that found in breeding grounds worldwide; (2) the mean span...

Sounds from humpback whale songs were analyzed to evaluate possible mechanisms of sound production. Song sounds fell along a continuum with trains of discrete pulses at one end and continuous tonal signals at the other. This graded vocal repertoire is comparable to that seen in false killer whales [Murray et al. (1998). J. Acoust. Soc. Am. 104, 167...

The competitive group appears to be a major component of the mating system of the humpback whale, Megaptera novaeangliae, bringing together a single female (nuclear animal or NA) and multiple males (escorts) that compete for physical proximity to her. We examined the relation of body size of the NA to the number of attending escorts and, separately...

In a recent publication in Biological Reviews, Manger (2006) made the controversial claim that the large brains of cetaceans evolved to generate heat during oceanic cooling in the Oligocene epoch and not, as is the currently accepted view, as a basis for an increase in cognitive or information-processing capabilities in response to ecological or so...

We dispute Penn et al.'s claim of the sharp functional discontinuity between humans and nonhumans with evidence in bottlenose dolphins (Tursiops truncatus) of higher-order generalizations: spontaneous integration of previously learned rules and concepts in response to novel stimuli. We propose that species-general explanations that are "bottom-up"...

Despite years of study, the humpback whale mating system remains an enigma. Sustained observations of subsurface behavior may help reveal important components of the mating system. In 2005 and 2006, we deployed Crittercam, an animal-borne imaging and data-logging tool, on humpback whales in their winter grounds. We focused our efforts on competitiv...

Print versions of presentations given by practitioners of animal-borne imaging research at the ABI Symposium held at National Geographic in 2007.

We examine the use of Singular Spectrum Analysis (SSA) technique as an alternative technique to using standard wavelet shrinkage schemes for the purpose of de-noising mixtures of tonals, transients and Gaussian noise. Wavelet schemes require a calculation of a threshold to determine which components are taken to be signal and noise. If the noise co...

A group of eminent cetacean researchers respond to headlines charging that dolphins might be "flippin' idiots". They examine behavioural, anatomical and evolutionary data to conclude that the large brain of cetaceans evolved to support complex cognitive abilities.

The authors tested whether the understanding by dolphins (Tursiops truncatus) of human pointing and head-gazing cues extends to knowing the identity of an indicated object as well as its location. In Experiment 1, the dolphins Phoenix and Akeakamai processed the identity of a cued object (of 2 that were present), as shown by their success in select...

A bottlenose dolphin was tested on its ability to echoically discriminate horizontal angular differences between arrays of vertically oriented air-filled PVC rods. The blindfolded dolphin was required to station in a submerged hoop 2 radial m from the stimuli and indicate if an array with two rods (S+) was to the right or the left of a single rod (...

Recent intense interest in social cognition in dol- phins reflects findings that wild dolphins live in com- plex societies that rely on individual recognition, a protracted period of development, coalition forma- tion, and cooperative, as well as competitive, social behaviors. Laboratory studies have revealed a host of cognitive skills that can sup...

A vertical array of five hydrophones was used to measure the acoustic field in the vertical plane of singing humpback whales. Once a singer was located, two swimmers with snorkel gear were deployed to determine the orientation of the whale and position the boat so that the array could be deployed in front of the whale at a minimum standoff distance...

Generalization of a rule is demonstrated if the rule governs a class of problem, and the subject, after successful experience with a limited number of problems, can apply the governing rule to new problems within that class. We show that the bottlenose dolphin (Tursiops truncatus) is capable of such generalization for classes of problems requiting...

Male humpback whales (Megaptera novaeangliae) produce long, structured sequences of sound underwater, commonly called "songs." Humpbacks progressively modify their songs over time in ways that suggest that individuals are copying song elements that they hear being used by other singers. Little is known about the factors that determine how whales le...

The authors tested 2 bottlenosed dolphins (Tursiops truncatus) for their understanding of human-directed gazing or pointing in a 2-alternative object-choice task. A dolphin watched a human informant either gazing at or pointing toward 1 of 2 laterally placed objects and was required to perform a previously indicated action to that object. Both stat...

The stereotypical stationary posture adopted by male humpback whales producing song suggests they are attempting to optimize transmission range. Over 23 days between Jan. 28 and Apr. 2 2003, we measured the sound fields of singers using divers equipped with rebreather scuba. A custom-designed "Aquahead" system reliably located singers to within 50...

Humpback whales migrate seasonally between high-latitude summer feeding grounds and low-latitude winter breeding grounds. Identification photographs of humpback whales were collected in the Hawaiian Islands between 1977 and 1995, and sighting histories were compiled for individuals. Analyses revealed that (a) mean dates of first identification were...

A vertical array of five hydrophones was used to measure the acoustic field of singing humpback whales. Once a singer was located, two swimmers with snorkel gear were deployed to determine the orientation of the whale and to position the boat so that the array could be deployed in front of the whale at a minimum standoff distance of 10 m. The spaci...

Summary form only given. Male humpback whales (Megaptera novaeangliae) produce long, complex vocalizations consisting of a hierarchically-structured sequence of distinctive broadband 'units', each of a few seconds' duration. The function of this 'song' remains unclear. Singers are often observed in a stationary position with their body inclined dow...

Humpback whales (Megaptera novaeangliae) produce cyclical, underwater sound sequences that are composed of a variety of structured sound patterns. These sequences have been described as songs and generally are assumed to serve a communicative function. Past studies of the sound patterns and individual sounds within songs often have described them a...

A bottlenose dolphin was tested on its ability to echoically discriminate horizontal angular differences between two arrays of vertical, air-filled, PVC rods. The blindfolded dolphin was required to station in a submerged, vertically-oriented hoop, 2 radial metres from the stimuli, and indicate whether an array with four rods (S+) was to the left o...

We examined the relation of body length of male humpback whales (Megaptera novaeangliae) to the social roles they adopted on the Hawaiian winter grounds: principal escort in a competitive group, secondary escort, lone escort to a mother-calf pair, male partner in a dyad, and singer. Using underwater videogrammetry, we measured body lengths of 17 pr...

Two experiments tested a bottlenosed dolphin's ability to match objects across echolocation and vision. Matching was tested from echolocation sample to visual alternatives (E-V) and from visual sample to echolocation alternatives (V-E). In Experiment 1, the dolphin chose a match from among three-alternative objects that differed in overall (global)...

Male humpback whales (Megaptera novaeangliae) outnumber females on the winter grounds and compete physically for proximity to females. Analyses of identification photographs collected in Hawai'i from 1976 through 1995 and scan samples collected in 1998 showed that (i) reproductive potential (calving rate) for the following winter was greater for fe...

The annual winter assembly of humpback whales (Megaptera novaeangliae) in tropical waters has been linked to reproductive activities, including birthing, calf-rearing, and mating. However, the sexual behaviour of this species remains largely undescribed and mating has never been witnessed. We examined 121 h of underwater videotaped foot-age of hump...

We assigned gestural symbols to nine body parts of a bottlenosed dolphin (Tursiops truncatus). The dolphin was first trained to touch any floating object it chose with the body part indicated by a gestural symbol. In Experiment 1, we tested the dolphin’s ability to now touchspecific gesturally referenced objects using specific gesturally referenced...

The songs of eight male humpback whales were recorded at ranges varying from 20 to 40 m with a vertical array of hydrophones that had a flat frequency response to 24 kHz. The songs consisted of bursts of sounds called units. Units were organized into phrases and phrases into themes. Most of the units had mean duration between 1 and 2 s and mean sil...

The mechanisms for cultural transmission remain disputable and difficult to validate through observational field studies alone. If controlled experimental laboratory investigation reveals that a putative mechanism is demonstrable in the species under study, then inferences that the same mechanism is operating in the field observation are strengthen...

A bottlenose dolphin was tested on its ability to echoically discriminate horizontal angular differences between two arrays of vertical, air?filled PVC rods. The blindfolded dolphin was required to station in a submerged vertically oriented hoop 2 radial meters from the stimuli and indicate if an array with four rods (S+) was to the left or the rig...

Two bottlenosed dolphins taught to classify pairs of three-dimensional objects as either same or different were tested with novel stimulus sets to determine how well their classification abilities would generalize. Both dolphins were immediately able to classify novel pairs of planar objects, differing only in shape, as same or different. When test...

The authors tested a dolphin's (Tursiops truncatus) understanding of human manual pointing gestures to 3 distal objects located to the left of, to the right of, or behind the dolphin. The human referred to an object through a direct point (Pd), a cross-body point (Px), or a familiar symbolic gesture (S). In Experiment 1, the dolphin responded corre...

The authors tested a dolphin's (Tursiops truncatus) understanding of human manual pointing gestures to 3 distal objects located to the left of, to the right of, or behind the dolphin. The human referred to an object through a direct point (Pd), a cross-body point (Px), or a familiar symbolic gesture (S). In Experiment 1, the dolphin responded corre...

We investigated whether a bottlenosed dolphin’s ability to recall and repeat actions on command would immediately generalize to actions performed with specified objects. The dolphin was tested on her ability to repeat 18 novel behaviors performed with potentially interchangeable objects specified using an artificial gestural language. Such “action...

Experiment 1 tested a dolphin (Tursiops truncatus) for cross-modal recognition of 25 unique pairings of 8 familiar, complexly shaped objects, using the senses of echolocation and vision. Cross-modal recognition was errorless or nearly so for 24 of the 25 pairings under both visual to echoic matching (V-E) and echoic to visual matching (E-V). First-...

Experiment 1 tested a dolphin (Tursiops truncatus) for cross-modal recognition of 25 unique pairings of 8 familiar, complexly shaped objects, using the senses of echolocation and vision. Cross-modal recognition was errorless or nearly so for 24 of the 25 pairings under both visual to echoic matching (V–E) and echoic to visual matching (E–V). First-...

Little is known about how animals represent their own actions in working memory. We investigated whether bottlenosed dolphins could recall actions they had recently performed and reveal those recollections using an abstract rule. Two dolphins were trained to respond to a specific gestural command by repeating the last behavior performed. Both dolph...

Pack and Herman (1995) revealed that in ‘‘cross‐modal’’ matching tests, a dolphin could spontaneously recognize the shape of an object through one sense (either echolocation or vision) that it had earlier interrogated through the alternate sense [A. A. Pack and L. M. Herman, J. Acoust. Soc. Am. 98, 722–733 (1995)]. Objects exposed to the echolocati...