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MARINE MAMMAL SCIENCE, 26(2): 501–507 (April 2010)
2010 by the Society for Marine Mammalogy
DOI: 10.1111/j.1748-7692.2010.00390.x
Dr. Amy Samuels, behavioral and conservation biologist, passed away in her home
on 9 December 2008 at the age of 57. She is survived by her daughter Lily Caiming,
her siblings Peter, Matthew and Joan, and eight nieces and nephews.
Many familiar with Amy’s work on cetaceans know that she came into our field
as a highly trained and experienced primatologist. However, she actually started
her amazing scientific journey first working with marine mammals, if only briefly,
with Sam Ridgway and Ken Norris. Amy was a participant in so many now-famous
projects that her career really was, to quote Forrest Gump, “like a box of chocolates,”
filled with a rich and diverse body of work.
Amy was involved with David Premack’s famous studies on chimpanzee cognition
at the University of California-Santa Barbara and the University of Pennsylvania
in the early mid-1970s, and with the ground breaking work on social primates
at UC Davis in the late 1970s. She spent five years working at Jeanne and Stuart
Altmann’s famous Amboseli baboon project in Kenya, conducted ground-breaking
work on dolphins at Chicago’s Brookfield Zoo, and worked on the two longest
running bottlenose dolphin research projects in Sarasota, Florida, and Shark Bay,
Western Australia. Those are only a few of the highlights from Amy’s diverse career,
which is why one or even a few people could not do justice to her In Memoriam notice.
In the late 1960s Sam Ridgway received a call from Amy, who was a student at
Antioch College and wanted to work with him at the Navy’s marine mammal facility
in San Diego. Sam said he could not pay her but she was welcome to come and assist.
So Amy hitchhiked across the country and enjoyed a few weeks working with Sam
before heading off to Sea Life Park in Hawaii for the summer to help Ken Norris and
his team with their dolphin research.
David Premack was on sabbatical at Harvard in the early 1970s when Amy
walked into his office out of a howling blizzard, dripping wet, and announced that
she would like to work with his chimpanzees. He hired Amy on the spot and she
became the principal trainer for the Premack project chimps. When Premack built
a new compound for his project at the University of Pennsylvania and left Santa
Barbara, Amy defied conventional practice at the time and insisted on personally
accompanying the animals in the holding area of the plane during the long flight
from California to Pennsylvania. This was just one of many examples of how she
always placed the well-being of animals first, and that dedication and compassion
for her study animals persisted throughout her life.
Amy was incredibly successful with chimps and worked with the animals coopera-
tively by treating them with the utmost respect and sensitivity. Her skills as a trainer
were extraordinary, and she was able to achieve amazing results. When David and
his wife Ann asked Amy to teach an aberrantly massive female chimp named Peony
to sit for “afternoon tea” as part of a behavioral exercise, she was able to accomplish
the task immediately. Ann and David later remarked that Peony made them look
like ruffians in comparison. Amy regaled many of us with amazing vignettes of her
work with the chimps, stories that would have made for a best-selling book.
Amy subsequently moved to UC Davis in the late 1970s to complete her un-
dergraduate degree in Anthropology (1979), and remained in Davis to complete
an MA in Ecology (1982). While Amy was completing her undergraduate course
work, she met Peter Rodman, a primatologist in the Anthropology Department, and
Joan Silk, a graduate student who was beginning her dissertation research, and the
three of them collaborated on a three-year study of social behavior and reproductive
strategies in a group of bonnet macaques housed at the California Regional Primate
Center (CRPC). This project ultimately produced the data for Amy’s Master’s thesis,
which focused on the events that led up to and followed a major reorganization of
the adult male dominance hierarchy (Samuels et al. 1984). The bonnet project also
produced some of the earliest evidence of substantial variation in female reproductive
success, and demonstrated that females compete actively for reproductive opportu-
nities (Samuels et al. 1987). While she was working on the bonnet project, Amy
developed a close working relationship with the professional staff of the CRPC, who
came to appreciate her deep knowledge of the behavior and welfare of the animals
in the bonnet colony, and she was asked to develop a position for the behavioral
management of the animals.
Amy’s extraordinary observational skills were already evident at Davis and she was
able to keep track of the most complicated events in the monkey group. She was
extremely focused when she was making observations and her attention never strayed
no matter how hot or cold or wet or windy it was. She always saw the animals as
individuals, with identities, personal histories, and idiosyncrasies. Amy’s data sheets
were annotated with detailed explanations of the context in which events occurred,
comments about the animals, and the occasional limerick.
In late 1982 Amy arrived in Kenya to manage the Amboseli Baboon Research
Project, a long-term primate field study that, by then, had accumulated 11 yr of
data on the baboons of the Amboseli basin. She came with an exceptional level
of dedication to the field work, as well as some of the best observation skills ever
brought to bear on the Amboseli baboon project. Her talent for observing subtle
details in behavior, combined with her careful and methodical nature, meant that
Amy collected very high quality data during her years in Amboseli and was “pre-
adapted” to soak up the quantitative methodology of the project, but she also left a
strong and enduring stamp on the project’s data collection protocols. A number of
her methods and innovations are still used today, such as the practice of recording the
movements of male baboons between social groups. One of her scientific contributions
from this period is an extraordinarily careful and detailed analysis of the energy
demands of motherhood (Altmann and Samuels 1992). Another is an analysis of
demographic patterns and male movements in the larger, basin-wide population of
baboons (Samuels and Altmann 1991). Amy’s most enduring legacy, however, is the
training she gave to new field-workers and the remarkable insights she shared with
them about animal behavior.
In 1986 Amy returned to the United States and continued studying baboon
social behavior as a staff scientist in the Department of Conservation Biology at
the Brookfield Zoo in Chicago. Amy’s unique talent with observing subtle but
important details in animal behavior was recognized and she was asked to apply
her skills to observing the zoo’s bottlenose dolphins to assist with management
decisions for the animals. Amy quickly realized that the dolphins’ social behavior
was fascinating but relatively unstudied compared to primates and other terrestrial
animals, so she adapted the focal-animal-sampling techniques she had learned in
Amboseli to document social and dominance relationships among the dolphins. Amy
was one of the first scientists to apply quantitative focal-animal-sampling techniques
to the study of marine mammal behavior and was a true pioneer in that field of
research. Her initial explorations of bottlenose dolphin behavior blossomed into an
array of behavioral studies that touched on nearly every aspect of dolphin social
life. Amy’s research of bottlenose dolphin populations at zoos and aquaria included
focused studies of pair bond relationships among males, matrilineal relationships
among females, behavioral development of calves and juveniles, the relationship
between hormones and behavior, dominance relationships, reconciliation behavior,
and integrated studies of behavior and vocalizations (e.g., Samuels and Gifford 1997).
While Amy was developing her studies at the Brookfield Zoo in the late 1980s,
Peter Tyack at the Woods Hole Oceanographic Institution (WHOI) began asking
colleagues in the primate field for suggestions of a skilled behavior observer who
would be interested in working on dolphins. There was a consistent refrain in the
answers—Amy Samuels. At the same time, Tyack was looking for an optimal zoo
or aquarium facility where he could record dolphin vocalizations while watching
the animals’ underwater behavior. Brookfield Zoo in Chicago had the perfect com-
bination of easily observed dolphins and Amy Samuels. During a visit by Tyack
to the Brookfield Zoo, Amy revealed the same kind of observational prowess that
had so impressed her colleagues in primatology. Tyack had observed dolphins gently
rubbing each other with their pectoral fins countless times before, but it was only
when watching dolphins with Amy that he came to fully appreciate the potential
importance of the behavior in understanding dolphin social relationships. Amy had
seen a strong correlation between the gentle rubbing of the dolphins and groom-
ing behavior in primates, and hypothesized that dolphin rubbing behavior was an
important indicator of affiliative social bonds between individual animals (Samuels
et al. 1989).
Amy was never one to let schooling get in the way of her education, but as she
developed her dolphin research, she realized that it was well suited to a Ph.D. thesis.
Amy liked the scientific and academic research community in Woods Hole, and was
able to arrange a unique degree program exclusively at WHOI in 1990 separate from
the traditional joint program between WHOI and MIT. She completed her thesis
in 1996 on social relations in bottlenose dolphins and included a comprehensive
review of the history of cetacean behavioral research (Samuels and Tyack 2000).
WHOI pulled out the stops for Amy’s graduation—most of the administration and
much of the Biology Department joined her family for a heartfelt celebration of her
accomplishments in the WHOI community.
When Amy was starting her degree program at WHOI, another research group
was looking for a keen observer to join their team, this time for field work on the
social behavior of dolphins in Western Australia. The Shark Bay Dolphin Research
project was learning a lot about the behavior of adult dolphins and mother-calf
pairs in Shark Bay but wanted to recruit a keen observer to tackle the most difficult
behavioral study of all: the social dynamics of juveniles. Again, all roads led to Amy
Samuels, who was excited about extending her dolphin observing skills from the zoo
setting to research on dolphins in the wild.
Amy’s field research on the behavioral development of juveniles in Shark Bay was
one of the first to focus on juvenile cetaceans and was complemented by her studies
of the social development of juvenile dolphins at the Brookfield Zoo. In her small
skiff, with colleague Cindy Flaherty and sometimes her young daughter Caiming
on board, Amy recorded the often fast-paced lives of the juvenile dolphins in Shark
Bay. Amy focused on identifying factors that influence the behavioral development
of juvenile dolphins and affect their survival to adulthood and ultimate reproductive
success. For young females, these include mothering skills and establishment of a
network of female associates via affiliative behavior; for young males, these include
alliance formation and behavioral synchrony with other males. Amy often told stories
about the dolphin “kids” being just that—kids: they do not always get it right the
first time but they keep on trying.
Amy wove her extensive experiences with dolphins into a children’s book titled
Follow That Fin: Studying Dolphin Behavior (2000). The book describes a day in the
life of a juvenile bottlenose dolphin as only Amy Samuels could relay, and was a
labor of love rooted in Amy’s dedication to children and devotion to her daughter
A major component of Amy’s research integrated her interest in behavior with her
life-long passion for conservation. Her expertise in behavioral science was utilized to
investigate the effects of anthropogenic noise on both small and large cetaceans, and
she worked on ground-breaking research projects in the Caribbean and Hawaii with
colleagues from several disciplines in the marine science arena (see Watkins et al.
1999, 2002).
Amy believed that learning about social relationships within wild dolphin societies
is an important part of ensuring the social and physical well-being of dolphins at
public display facilities. She designed and implemented a landmark study, funded
by the National Oceanic and Atmospheric Administration (NOAA) that evaluated
“Swim-With-Dolphin” programs and showed that not all programs were the same or
equal. Samuels and Spradlin (1995) described and quantified “High Risk” behaviors
that occurred at some of the facilities, which placed dolphins and people in danger.
The data collected during the study provided the responsible government regulatory
agencies and facility owners with comprehensive information on how to better
manage the programs and safeguard both the dolphins and human participants.
The success of Amy’s work evaluating human-dolphin interaction concerns in
the captive setting enabled her to tackle the same subject with animals in the
wild. Amy, along with her prot´
es, students, and colleagues, studied the effects
of tourism and other human activities on wild dolphins in the U.S. and Australia,
and those data provided important insights for government officials to implement
conservation initiatives for the animals (see Samuels et al. 2000; Bejder and Samuels
2003; Samuels et al. 2003a,b; Samuels and Bejder 2004; Bejder et al. 2006a,b, 2009).
For example, in partnership with Western Australia’s Department of Conservation
and Land Management (CALM), Amy’s work provided a strong scientific basis for
managing tourist activities in Shark Bay and minimizing the negative effects of
interactions between people and dolphins at Monkey Mia. In the United States her
work along the Florida panhandle and in the Florida Keys helped NOAA implement
conservation plans for protecting dolphins from illegal harassment by recreational
and commercial boaters, and helped forge cooperative partnerships with dolphin tour
operators for NOAA’s “Dolphin SMART” program.
Whether she was working on primates or cetaceans, studying them at facilities or
in the wild, or focusing on social behavior or conservation questions, Amy Samuels
was always the consummate teacher, passing on her knowledge and skills to colleagues
and young researchers. As we hope to have conveyed, Amy had an incredibly diverse
career, as a researcher, conservationist, and mentor, but there was one constant: in
every period and in every place she worked, she made deep and lasting friendships.
Amy is very much missed, but her legacy and contributions to behavioral science
and wildlife conservation live on.
Altmann, J., and A. Samuels. 1992. Costs of maternal care: Infant-carrying in baboons.
Behavioral Ecology and Sociobiology 29:391–398.
Bejder, L., and A. Samuels. 2003. Evaluating impacts of nature-based tourism on cetaceans.
Pages 229–256 in N. Gales, M. Hindell and R. Kirkwood, eds. Marine mammals:
Fisheries, tourism and management issues. CSIRO Publishing, Collingwood, Australia.
Bejder, L., A. Samuels, H. Whitehead, N. Gales, J. Mann, R. Connor, M. Heithaus, J.
Watson-Capps, C. Flaherty and M. Kr¨
utzen. 2006a. Decline in relative abundance
of bottlenose dolphins (Tursiops sp.) exposed to long-term disturbance. Conservation
Biology 20:1791–1798.
Bejder, L., A. Samuels, H. Whitehead and N. Gales. 2006b. Interpreting short-term be-
havioural responses to disturbance within a longitudinal perspective. Animal Behaviour
Bejder, L., A. Samuels, H. Whitehead, H. Finn and S. Allen. 2009. Impact assess-
ment research: Use and misuse of habituation, sensitisation and tolerance to describe
wildlife responses to anthropogenic stimuli. Marine Ecology Progress Series 395:177–
Samuels, A. 2000. Follow that fin: Studying dolphin behavior. Raintree-SteckVaughn Pub-
lishers, Austin, Texas.
Samuels, A., and J. Altmann. 1991. Baboons of the Amboseli basin: Demographic stability
and change. International Journal of Primatology 12:1–9.
Samuels, A., and T. R. Spradlin. 1995. Quantitative behavioral study of bottlenose dolphins in
Swim-With-Dolphin programs in the United States. Marine Mammal Science 11:520–
Samuels, A., and T. Gifford. 1997. A quantitative assessment of dominance relations among
bottlenose dolphins. Marine Mammal Science 13:70–99.
Samuels, A., and P. Tyack. 2000. Flukeprints: A history of studying cetacean societies. Pages
9–44 in J. Mann, R. C. Connor, P. L. Tyack and H. Whitehead, eds. Cetacean societies:
Field studies of dolphins and whales. University of Chicago Press, Chicago, IL.
Samuels, A., and L. Bejder. 2004. Chronic interaction between humans and free-ranging
bottlenose dolphins near Panama City Beach, Florida, USA. Journal of Cetacean Research
and Management 6:69–77.
Samuels, A., J. B. Silk and P. S. Rodman. 1984. Changes in the dominance rank and re-
productive behavior of male bonnet macaques (Macaca radiata). Animal Behaviour
Samuels, A., J. B. Silk and J. Altmann. 1987. Continuity and change in dominance relations
among female baboons. Animal Behaviour 35:785–793.
Samuels, A., M. Sevenich, T. Gifford, T. Sullivan and J. Sustman. 1989. Gentle rubbing
among bottlenose dolphins. Page 58 in Abstracts, Eighth Biennial Conference on the
Biology of Marine Mammals, 7–11 December 1989, Pacific Grove, CA.
Samuels, A., L. Bejder and S. Heinrich. 2000. A Review of the literature pertaining to
swimming with wild dolphins. Report to the Marine Mammal Commission, Contract
Number T74463123. 57 pp.
Samuels, A., L. Bejder, B. Chicoski, L. Engleby and A. Mehta. 2003a. An annotated bibliog-
raphy pertaining to human interaction with terrestrial wildlife. Report to the Marine
Mammal Commission, Contract Number T74463123. 14 pp.
Samuels, A., L. Bejder, R. Constantine, and S. Heinrich. 2003b. A review of swimming with
wild cetaceans with a specific focus on the Southern Hemisphere. Pages 277–303 in
N. Gales, M. Hindell and R. Kirkwood, eds. Marine mammals: Fisheries, tourism and
management issues. CSIRO Publishing, Collingwood, Australia.
Watkins, W. A., M. A. Daher, N. A. DiMarzio, A. Samuels, D. Wartzok, K. M. Fristrup,
D. P. Gannon, P. W. Howey, R. R. Maiefski and T. R. Spradlin. 1999. Sperm whale
surface activity from tracking by radio and satellite tags. Marine Mammal Science
Watkins, W. A., M. A. Daher, N. A. DiMarzio, A. Samuels, D. Wartzok, K. M. Fristrup, P.
W. Howey and R. R. Maiefski. 2002. Sperm whale dives tracked by radio telemetry.
Marine Mammal Science 18:55–68.
SUSAN ALBERTS, Duke University, Durham, North Carolina 27708, U.S.A.;
JEANNE ALTMANN, Princeton University, Princeton, New Jersey 08544, U.S.A.;
LARS BEJDER, Murdoch University, Perth, Western Australia 6150, Australia;
RICHARD CONNOR, University of Massachusetts Dartmouth, North Dartmouth,
Massachusetts 02747-2300, U.S.A.; MARY ANN DAHER, Woods Hole Oceano-
graphic Institution, Woods Hole, Massachusetts 02543, U.S.A.; LAURA ENGLEBY,
NOAA/National Marine Fisheries Service, St. Petersburg, Florida 33701, U.S.A.;
CINDY FLAHERTY, Chicago Zoological Society, Chicago, Illinois 60513, U.S.A.;
DAV I D PREMACK, University of Pennsylvania, Philadelphia, Pennsylvania 19104,
U.S.A.; ANDREW READ, Duke University Marine Lab, Beaufort, North Carolina
28516-9721, U.S.A.; SAM RIDGWAY, U.S. Navy Marine Mammal Program, San
Diego, California 92152, U.S.A.; JOAN SILK, University of California Los Angeles,
Los Angeles, California 90095, U.S.A.; TREVOR SPRADLIN, NOAA/National Ma-
rine Fisheries Service, Silver Spring, Maryland 20910-6233, U.S.A.; PETER TYA C K ,
Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, U.S.A.
ResearchGate has not been able to resolve any citations for this publication.
Full-text available
Swim-with' activities, in which humans enter the water to interact with free-ranging cetaceans, are a popular form of nature tourism; however, there is considerable disagreement as to whether these encounters constitute a threat to the animals. At the request of the US Marine Mammal Commission, a systematic study was designed to quantify effects of swim-with activities on the behaviour of bottlenose dolphins in waters near Panama City Beach, Florida. Certain dolphin behaviours were identified as indicative of chronic interaction with humans, and based on presence of these behaviours, at least seven dolphins were identified that permitted people to swim nearby. Because these dolphins accepted food handouts from people, they were considered to be conditioned to human interaction through food reinforecement. Specific human-dolphin interactions that posed a risk for dolphins or humans were identified, and it was calculated that human interaction put a specific juvenile dolphin at risk once every 12 min, including being fed by humans once every 39-59 min. Humans interacting with that dolphin were estimated to be at risk once every 29 min. Although the study was of limited duration, the observations were so clear-cut and the nature of interactions so potentially hazardous it was concluded that food provisioning was the probable basis for swimming with free-ranging dolphins near Panama City Beach, Florida, and therefore, human interaction at this location was likely to be harmful to the dolphins and in clear violation of the US Marine Mammal Protection Act. Of equal importance to the findings of this study is the methodology. A systematic behavioural methodology was designed that can be adapted to study potential impacts of nature tourism on coastal communities of cetaceans in which individuals are readily distinguished. The focus was on the behaviour of individual animals in order to describe and quantify in-water interactions between dolphins and humans, to make behavioural comparisons for the same individual dolphins in the presence and absence of swimmers, and to make behavioural comparisons for individual dolphins in the same region that do and do not interact with swimmers. Coupled with standard photo-identification techniques, these methods can be used to identify the class of animals, or proportion of a local community, that is more likely to interact with, be detrimentally affected by, and/or avoid human interaction. Sequential observations of the same individuals taken over time can be used to document habituation or sensitisation to human interaction.
Full-text available
We documented immediate, behavioural responses of Indo-Pacific bottlenose dolphins (Tursiops sp.) to experimental vessel approaches in regions of high and low vessel traffic in Shark Bay, Western Australia. Experimental vessel approaches elicited significant changes in the behaviour of targeted dolphins when compared with their behaviour before and after approaches. During approaches, focal dolphin groups became more compact, had higher rates of change in membership and had more erratic speeds and directions of travel. Dolphins in the region of low vessel traffic (control site) had stronger and longer-lasting responses than did dolphins in the region of high vessel traffic (impact site). In the absence of additional information, the moderated behavioural responses of impact-site dolphins probably would be interpreted to mean that long-term vessel activity within a region of tourism had no detrimental effect on resident dolphins. However, another study showed that dolphin-watching tourism in Shark Bay has contributed to a long-term decline in dolphin abundance within the impact site (Bejder et al., in press, Conservation Biology). Those findings suggest that we documented moderated responses not because impact-site dolphins had become habituated to vessels but because those individuals that were sensitive to vessel disturbance left the region before our study began. This reinterpretation of our findings led us to question the traditional premise that short-term behavioural responses are sufficient indicators of impacts of anthropogenic disturbance on wildlife.
A bstract Agonistic behavior of bottlenose dolphins was studied at Brookfield Zoo for nearly 4.5 yr, and dominance relationships were determined using a quantitative technique adapted from primate behavioral research. Dominance relations among dolphins were influenced by the gender of participants. Male dolphins were clearly and consistently dominant to females, and intersexual agonism occurred at moderate rates with seasonal peaks in spring and fall. Dominance relationships among female dolphins were age‐ordered and stable, even though agonism among females did occur at uniformly low rates. In contrast, the two males had a changeable dominance relationship in which periods of stability and low‐level agonism were interspersed with episodes of intense competition. Zoo‐based research revealed patterns of behavior that conformed to current knowledge about bottlenose dolphin social structure. Moreover, research in a zoo setting facilitated development of a quantitative technique that can be used to assess cetacean dominance relationships in field research.
A bstract Dives of a 12‐m sperm whale ( Physeter catodon Linnaeus, 1758) were tracked in the southeast Caribbean by long range, 30 MHz radio tag with dive‐profile telemetry over 4.6 d, 26 April‐1 May 1995. Over the 295‐km track, average speed was 0.7 m/sec (2.6 km/h). Of 158 dives (defined as submergences longer than 3 min), 65 were shallow (<200 m). The 93 deep dives averaged 990 m (range 420–1,330 m) in depth, and 44.4 min in duration (range 18.2–65.3 min). Water depth was at least 200 m deeper than the whale dive depth. The whale was engaged in activities at or near the surface, shallow dives, and deep dives during 22.6%, 23.4%, and 54% of the time, respectively. Depth and duration of dives were correlated, but there was little relationship between the length or depth of dives with the duration of surfacings either before or after dives. Deep dives occurred day and night. In 44.4% of the deep dives, the vertical movement of descents and ascents was interrupted at intermediate depths, lengthening these dives by an average of 10.8 min. During dives without stops at intermediate depths, descents averaged 11 min at 1.52 m/sec, and ascents averaged 11.8 min at 1.4 m/sec.
A bstract Three 12‐m sperm whales ( Physeter catodon ) were tagged and tracked west of Dominica in the southeast Caribbean to follow the surfacing patterns and movements of these presumed subadult males. Whale N was tagged in April 1993 with a 30‐MHz radio tag and tracked for two days. Whale H was tagged in April 1995 with a 30‐MHz radio tag and tracked for 4.6 d. Whale A was tagged in April 1995 with a satellite‐monitored tag tracked by ARGOS for 21.5 d, the first four of which were concurrent with the tracking of Whale H, an associate. The tagged whales remained west of Dominica for at least 2, 5, and 13 d, respectively. Whales N and A then moved southward to waters off Martinique. There were no apparent effects on the whales by tagging or the presence of the tags. The whales averaged speeds of 2.6‐3.5 km/h. Surfacings, indicated by tag signals, were of two types: short surfacings apparently primarily for respiration, averaging 7‐10.5 min between repeated longer dives, occurring day and night; and extended surfacings seemingly for rest and social interactions with conspecifics, occurring mostly in daylight. Whales were near the surface for 20.4%–22.6% of the total time (26.6%–27.1% during the day and 14.9%–17.1% at night). Delayed blowing was observed as Whale N surfaced for 8.3 min between 47‐ and 45‐min dives but delayed the first of its 31 blows for 1.5 min after surfacing.
A bstract The behavior of dolphins in four Swim‐With‐Dolphin programs was compared by type of Swim encounter, defined by the presence (“Controlled“) or absence (“Not‐Controlled“) of explicit trainer regulation of interactions between dolphins and human swimmers. Dolphin‐swimmer interactions involving aggressive, submissive, or sexual behavior were designated as “high‐risk” in the Swim context; sexual behavior was included as high‐risk based on analyses that demonstrated co‐occurrence of sexual and agonistic behaviors. High‐risk activity comprised a substantial proportion of dolphin‐swimmer social activity during Not‐Controlled Swims. In contrast, high‐risk activity rarely occurred during Controlled Swims, even though agonistic and sexual behaviors were normal components of the same dolphins’ free‐time social repertoire. These results indicated that direct trainer control of dolphin‐swimmer interactions virtually eliminated high‐risk activity from the Swim context, and thereby diminished the potential for dolphin distress, swimmer injury, and rejection of dolphins from Swim programs due to swimmer injury. This study illustrates effective use of quantitative behavioral sampling techniques for evaluation of captive management concerns and promotes broader use of these techniques for a better understanding of cetacean behavior.
Infant-carrying, the most costly form of primate parental care other than lactation, was investigated in savannah baboons of Amboseli, Kenya. Measurements of physical growth, counts and length of paces, and simultaneous records of carrying and locomotion were used to evaluate the time, distance, and energetic expenditure of infant-carrying. Finally, we modeled the energetics of independent infant locomotion and considered ontogenetic patterns in the alternative energetic costs of carrying versus independent infant locomotion under assumptions of complete nutritional dependency. The youngest infants were carried by their mothers during all travel and foraging, for a total of 8–10 km/day. By 8 months of age, both carrying time and distance were almost zero. However, daily carrying distance, unlike carrying time, did not decline in the first few months, because older infants were carried disproportionately during rapid travel and, consequently, for greater travel distances per unit carrying time. Females of low dominance rank carried their infants the most; the highest ranking mothers not only carried their infants least but biased their carrying against sons. Although carrying a growing infant is an increasingly costly behavior, during the period of nutritional dependence energetic costs to the mother are appreciably greater if an infant travels independently instead of being carried by its mother. Yet infants increased locomotor independence at a younger age than predicted by a simple model of maternal energetic efficiency. Trade-offs in energetic economy may enhance a mother's future reproduction at the expense of her present infant, may enhance survival of the present infant by promoting early acquisition of developmentally essential skills, or may suggest the importance of additional factors that influence the mother's and infant's behavior.
A cross-sectional demographic analysis of the entire baboon population of the Amboseli basin of southern Kenya was undertaken to complement the lon-gitudinal, intensive studies of a subpopulation. The present survey documented the extent and persistence of the influx of anubis baboons into the predominantly cynocephalus community and provided another example of the nonrandom dispersal patterns of cercopithecine males. In addition, the survey confirmed continued demographic stability of the basinwide baboon population and even growth in groups that had access to better feeding conditions, despite decline of the baboons' preferred habitat and expansion of human activities into wildlife areas. Conflicts with activities of humans, however, indicate that the present well-being of the Amboseli baboon population may be short-lived.
Female baboons, Papio cynocephalus, in Amboseli National Park establish linear dominance hierarchies in which maternal kin usually occupy adjacent ranks. Previous work had shown that few changes in the relative rank order of matrilines had occurred between 1971 and 1981 (Hausfater et al. 1982). During a 9-month period beginning in December 1982, the rate and magnitude of changes in matrilineal rank order accelerated. Major changes in the relative ranks of members of a few matrilines resulted in changes in the absolute ranks of females of all but one matriline. However, the ordering between many pairs of matrilines did not change and the genealogical structure of dominance relations was generally maintained. This brief period of rapid change was succeeded by a period of slow change and relative stability in dominance relations, lasting at least 27 months. Data from the 15-year period suggest that the rates of change in female dominance relations are variable: long periods of stability are sometimes punctuated by short periods of instability and change. No single explanation accounted for this variability.