[MARMAM] Abstracts and contents - Aquatic Mammals, 32(1), 2006 (fwd)

MARMAM Editors marmamed at uvic.ca
Tue May 30 22:42:44 PDT 2006


Dear Marmam and ECS-mailbase subscribers,

Apologies in advance to those of you who will be receiving cross-postings.

The following is a list of contents of the most recent issue of _Aquatic
Mammals_. This publication is supported through a partnership between the
European Association for Aquatic Mammals and the European Cetacean
Society. For more information on _Aquatic Mammals_, I refer you to the new
website for the publication (that includes author guidelines) which not
only also has links to both societies:

http://www.wiu.edu/users/aquamamm/index/home.htm

The abstracts are posted as a courtesy to the journal editors: Managing
Editor: Dr. Jeannette Thomas, Department of Biological Sciences, Western
Illinois University-Quad Cities, 3561 Street, Moline, Illinois 61265, USA
(J-Thomas at wiu.edu; tel: 309-762-9481; fax: 309-762-6989) and Co-Editor and
Book Review Editor: Dr. Kathleen Dudzinski, Mystic Aquarium & Institute
for Exploration, 55 Coogan Avenue, Mystic, Connecticut 06355, USA
(kdudzinski at mysticaquarium.org; tel: 860-572-5955; fax: 860-572-5969).

The addresses to whom reprint inquiries should be directed is included
with each article. No email addresses were provided with any of the
articles. Thank you for your continued interest in this journal and
publication postings in general.

With warm regards,

Dagmar Fertl
Geo-Marine, Inc.
dfertl at geo-marine.com
http://www.geo-marine.com
____________________________________________________________________________

Neumann, D.R.*, and M.B. Orams. 2006. Impacts of ecotourism on
short-beaked common dolphins (Delphinus delphis) in Mercury Bay, New
Zealand. Aquatic Mammals 32(1):1-9.

*Luisenstrasse 2, 76530 Baden-Baden, Germany

Short-beaked common dolphins (Delphinus delphis) often are found in large
aggregations offshore from the eastern coast of New Zealand. They are the
primary target of at least six marine mammal tourism operations from
Whakatane to the Hauraki Gulf. This report details the first long-term
investigation of interactions between tourists and common dolphins. During
a 3-y study offshore from Whitianga on the Coromandel Peninsula, 105 focal
group follows, totaling 118 h of observations were conducted from a 5.5-m,
rigid-hull inflatable boat. Seventy-two of these observations were
conducted in the absence of the tour boat (baseline), and 33 with the tour
boat. Baseline data were compared with "tour boat" data to assess changes
in dolphin behaviour resulting from the tour boat approaching and swimmers
entering the water to snorkel with the dolphins.

Common dolphins responded with a relatively predictable pattern to
approaching boats. Initial attraction (mean duration 8 min) typically was
followed by neutral behaviour (mean duration 57 min) and eventually
replaced by boat avoidance. Smaller dolphin groups showed boat avoidance
sooner and more frequently than larger groups. When swimmers entered the
water, dolphins only spent an average of 2 min in their vicinity.
Throughout encounters, they maintained a distance of at least 3 m from the
nearest swimmer. During half of the attempted swims, dolphins did not
change their course or their activity in response to swimmers. Swimmers
had a better chance of a sustained interaction when the group of dolphins
was large (> 50 individuals) and/or the number of swimmers in the water
was small (< 5). The results of this study suggested that common dolphins
can be affected by tourism; however, adherence to New Zealand's Marine
Mammals Protection Regulations and the current low level of tourism appear
to minimise the impact on this species.

*******************************************************************

Weiss, J.* 2006. Foraging habitats and associated preferential foraging
specializations of bottlenose dolphin (Tursiops truncatus) mother-calf
pairs. Aquatic Mammals 32(1):10-19.

Current address: Geo-Marine, Inc. 2713 Magruder Boulevard, Suite D,
Hampton, VA 23666, USA

Bottlenose dolphins (Tursiops truncatus) use a variety of foraging
specializations to detect and pursue prey. Like other mammals, individual
dolphins may use specialized foraging techniques that are shaped in
response to habitat type or prey resources. The long duration of the
mother-calf bond presents an opportunity for mothers to transmit such
specializations to their calves. This study explored how the use of
foraging specializations may influence selection of foraging habitats and
how such specializations may spread within a dolphin community. Focal
animal follows were used to document the foraging behavior of five
resident females and their calves from June to August 2003 in Sarasota
Bay, Florida. Sarasota Bay was classified into six habitat types based
upon bathymetry and bottom topography. Individual females differed in
their selection of foraging habitats. Three of the five focal females used
one of two foraging specializations—kerplunking and
barrier-feeding—and exhibited a preference for only one type of
behavior. A significant difference in the frequency of observations of
foraging specific behaviors was found between different habitat types.
Limited observations, as well as anecdotal evidence from past studies,
suggest that maternal transmission may play a role in the spread of
foraging techniques, such as kerplunking and barrier-feeding, within the
community. My findings suggest that the use of foraging specializations is
associated with foraging habitat preferences in Sarasota Bay. The
importance of seagrass areas to foraging dolphins and the significance of
the mother-calf bond to the development of the use of foraging
specializations is emphasized.
***********************************************************************
Reyes, L.M.* 2006.  Cetaceans of central Patagonia, Argentina. Aquatic
Mammals 32(1):20-30

*Universidad Nacional de la Patagonia San Juan Bosco, Boulevard Brown
3700, (9120) Puerto Madryn, Chubut, Argentina

The aim of this study was to produce the first annotated checklist of
cetaceans found in the coastal waters of central Patagonia, Argentina, in
the Southwestern Atlantic, encompassing approximately 700 km of coastline.
Personal records of sightings and strandings, personal communications with
trained individuals, photographs, unpublished abstracts from meetings,
scientific publications, newspaper articles, and specimen collections from
academic institutions were considered. Thirteen species were reported in
the area, including ten odontocetes and three mysticetes. Reports of eight
species had been published previously, including Cephalorhynchus
commersonii, Lagenorhynchus obscurus, L. australis, Orcinus orca,
Globicephala melas, Physeter macrocephalus, Mesoplodon layardii, and
Ziphius cavirostris. Five species were formally documented for the first
time in this coastal area, including Grampus griseus, M. grayi, Eubalaena
australis, Balaenoptera bonaerensis, and B. musculus. The number of
odontocete species and the presence of three species of pinnipeds breeding
or moulting on several islands (Otaria flavescens, Arctocephalus
australis, and Mirounga leonina) highlight the importance of the area in
terms of biodiversity of top predators and the need for the creation of a
new Marine Protected Area, considering present uses and trends in coastal
development.
***********************************************************************
McFadden, K.W.*, G.A.J. Worthy, and T.E. Lacher. 2006. Photogrammetric
estimates of size and mass in Hawaiian monk seals (Monachus
schauinslandi). Aquatic Mammals 32(1): 31-40.

*current address: National Marine Fisheries Service, Office of Protected
Resources Division, Silver Spring, MD 20910, USA

A non-invasive photographic technique was developed to estimate the body
mass of Hawaiian monk seals (Monachus schauinslandi). Newly weaned monk
seal pups (n = 31) were photographed and measured at Kure Atoll in the
northwestern Hawaiian Islands. Length, side area, anterior/posterior area,
and perimeter were measured from photographs to establish predictive
relationships with body mass using regression analyses. Photographs were
ranked subjectively in terms of quality, based on the degree to which the
seal's body position deviated from the ideal position used to obtain
standardized photographs. Results indicated that deviations in body
positioning (e. g., a seal rolled on its side) did not significantly alter
photogrammetric (surface area or perimeter) values compared to those
obtained in a standard position.

Although the most reliable models (based on information criterion analysis
and 95% CIs) were based on directly measured morphological variables,
models using only photogrammetric variables also yielded practical and
reliable models with 95% CI, ranging from ± 4.95 to 9.12 kg and R2 values
from 0.93 to 0.77. This finding indicated that the use of photogrammetry
alone to assess body condition is suitable to estimate body mass in 10- to
120-kg weaned Hawaiian monk seal pups.
***********************************************************************
Ortiz, R.M.*, and G.A.J. Worthy. 2006. Body composition and water turnover
rates of bottle-fed West Indian manatee (Trichechus manatus) calves.
Aquatic Mammals 32(1):41-45.

*current address: Division of Natural Sciences, University of California,
Merced, CA 95344-0039, USA

Estimation of body composition and water turnover rates can provide
important indices of an animal's health and well-being. This data becomes
especially important for a highly endangered species, such as the West
Indian manatee (Trichechus manatus). Information on body composition and
water turnover rates in nursing manatee calves is unavailable; therefore,
the present study describes a unique opportunity to estimate, by isotopic
dilution, body composition and water flux in vivo in bottle-fed calves of
the West Indian manatee held in captivity. A calf held in fresh water was
measured at 9 mo (124.8 kg) and 12 mo (152.6 kg) to examine the effects of
growth. Over this 3-mo period, absolute fat mass (FM) increased 70.4% and
absolute water turnover rate increased from 4.7 to 9.7 l/d, illustrating
how these parameters change as a function of the animal's growth. To
examine the effects of salinity on water flux, another calf (110.0 kg),
held in salt water, was restricted from fresh water. During freshwater
restriction, the calf's water turnover rate was 2.9 l/d and could be
accounted for solely by dietary and metabolic water. When the animal was
given access to fresh water, turnover rate increased to 4.0 l/d, for which
1.3 l/d could not be accounted, suggesting that nursing calves do not
drink salt water. Collectively, the results provide a unique data set for
nursing manatee calves and suggest that nursing calves, similar to adults,
do not engage in mariposia. In addition, nursing calves will drink when
given access to fresh water; however, the contribution of drinking fresh
water to the growth and development of nursing calves remains to be
examined. These data should provide useful information when implementing
the proper husbandry and management plans for both fresh- and saltwater
habitats of such a highly endangered species as the West Indian manatee.
********************************************************** Turner, J.P.*,
L.S. Clark, E.M. Haubold, G.A.J. Worthy, and D.F. Cowan. 2006. Organ
weights and growth profiles in bottlenose dolphins (Tursiops truncatus)
from the northwestern Gulf of Mexico. Aquatic Mammals 32(1):46-57.

*current address: Department of Marine Science, University of Hawai’i at
Hilo, Hilo, HI 96720, USA

Systematic necropsies were performed on 63 bottlenose dolphins (Tursiops
truncatus), and data on organ mass, standard body length (SBL), body mass
(BM), gender, sexual maturity, and age were measured and/or estimated.
Animals were extremely fresh and recovered from along the Texas and
Louisiana coastline in the northwestern Gulf of Mexico. Organ reference
tables were established for this species to facilitate comparisons with
other bottlenose dolphins and to provide a baseline for other cetacean
species. Organs examined included lungs, adrenal glands, kidneys, testes,
ovaries, heart, liver, pancreas, brain, pituitary, thyroid, thymus, and
spleen. Individuals were separated into three size classes: < 175 cm,
175-225 cm, and > 225 cm, based on SBL to further facilitate comparisons.
Growth rates of length and mass were described using Gompertz nonlinear
models as a function of gender. No sexual dimorphism was identified in BM
or organ weights, and SBL was only significantly larger for older mature
males. SBL and BM were strongly correlated with age when all animals were
included in analyses, although this is not an accurate predictor of age,
especially in older individuals. Organ weights were significantly
correlated with both SBL (except thymus and spleen) and BM (except left
ovary, spleen, and thymus). Age was significantly correlated with all
organ weights (except thymus, thyroid, and ovaries). There were no
significant differences in the weight of any paired organs (adrenal
glands, kidneys, lungs, ovaries, testes), and all were significantly
correlated with BM. These data on organ weights of bottlenose dolphins,
when interpreted with SBL, BM, and age, are significant tools for
pathologists and veterinarians interpreting animal health status.
*******************************************************************
Mellish, J.E.*, D.G. Calkins, D.R. Christen, M. Horning, L.D. Rea, and
S.K. Atkinson. 2006. Temporary captivity as a research tool: Comprehensive
study of wild pinnipeds under controlled conditions. Aquatic Mammals
32(1):58-65.

*School of Fisheries and Ocean Sciences, University of Alaska-Fairbanks,
Fairbanks, AK 99775, USA

A new approach to the study of free-ranging, endangered western stock
Steller sea lions (Eumetopias jubatus) was implemented at the Alaska
SeaLife Center in Seward, Alaska. Groups of up to four juvenile (n = 16)
Steller sea lions were held in temporary quarantine for research periods
of up to three months. Hematological and blood chemistry parameters were
collected at the beginning and end of captivity and compared to
free-ranging juvenile controls to determine if animals in temporary
captivity can provide accurate physiological data representative of their
wild counterparts. Free-ranging pups and juveniles were compared for
hematological differences related to developmental stage. Overall,
temporarily captive animals did not differ from free-ranging juveniles.
Seven of 17 blood parameters measured changed significantly during
captivity, likely as a function of a regular schedule and low-impact
nutritional studies (e.g., increased mass, cholesterol, total protein, and
globulins). A decrease in white blood cells during the study period (10.4
± 0.59 to 7.9 ± 0.33 m/mm3) to levels lower than that of free-ranging
animals (10.7 ± 0.40 m/mm3) indicated a drop in overall stress during
captivity despite research and handling procedures. Calcium increased with
captivity duration, suggesting that physiological changes can begin in
even limited time frames. Eight parameters related to immune status and
diet differed significantly between juveniles and pups from the same
geographical region. A strategy that combines the benefits of an extended
research design with temporary holding of free-ranging animals is proposed
as an alternative to traditional field methods for some types of focused
physiological studies.
********************************************************************
Fellner, W.*, K. Odell, A. Corwin, L. Davis, C. Goonen, I. Larkin, and
M.A. Stamper. 2006. Response to conditioned stimuli by two rehabilitated
and released West Indian manatees (Trichechus manatus latirostris).
Aquatic Mammals 32(1):66-74.

*The Living Seas, Epcot, Walt Disney World Resort, Lake Buena Vista, FL
32830, USA

U.S. regulations discourage research that requires training with West
Indian manatees (Trichechus manatus latirostris) due to the concern that
trained manatees would become accustomed to approaching humans for food
and would continue to approach people once released back to the wild.
Learning theory suggests that behaviors acquired while in captivity may
not transfer well to the new context of the wild habitat, however. In this
study, two female, rehabilitating manatees were trained to perform up to
five husbandry behaviors. Prior to their release, the behaviors were no
longer reinforced. Response to training signals was reduced for all
behaviors when reinforcement was with-held. In post-release observations,
the manatees were located by satellite and radio-telemetry, and training
signals were presented. Neither manatee performed any of the trained
behaviors. The results of this case study suggest that training releasable
manatees may be a viable option.
********************************************************************
Kjeld, M.*, Ö Ólafsson, G. Víkingsson, and J. Sigurjónsson. 2006.
Sex hormones and reproductive status of the North Atlantic fin whales
(Balaenoptera physalus) during the feeding season. Aquatic Mammals
31(2):75-84.

*The University Hospital, Department of Clinical Chemistry, K-bygging,
Landspítalinn v Hringbraut, 101 Reykjavík, Iceland

Reproductive fin whales (Balaenoptera physalus) (448 females and 278
males), classified by anatomical/histological methods, were studied for
serum sex hormones. Of the 207 females classified as pregnant by
anatomical methods, 95% had progesterone (P) levels higher than 9.0 nmol/l
with a near symmetrical distribution of log10 P-levels around the mean of
1.55 (35.5 nmol/l geometric mean). More than half of the sexually immature
females (n = 157) had P-levels ≤ 0.1 nmol/l. Nonpregnant mature cows
were older on average than pregnant cows, suggesting the beginning of
reproductive senescence in females before the age of 30 y. The mean serum
testosterone (T) of mature males (3.1 nmol/l) was significantly higher
than that of immature males (1.0 nmol/l). In mature males, T-levels were
positively associated with testicular size, as well as time (day-count)
during the summer whaling season. For fin whales, serum P- and T-levels
agreed closely with anatomical studies of reproduction and may be decisive
when anatomical indexes fail. Furthermore, the serum T-level appears to be
an excellent index for monitoring the latter part of the annual male
reproductive cycle.
***********************************************************************
Trites, A.W.*, B.P. Porter, V.B. Deecke, A/P. Coombs, M.L. Marcotte,
D.A.S. Rosen. 2006. Insights into the timing of weaning and the attendance
patterns of lactating Steller sea lions (Eumetopias jubatus) in Alaska
during winter, spring, and summer. Aquatic Mammals 32(1):85-97.

*Marine Mammal Research Unit, Fisheries Centre, University of British
Columbia, Room 247, AERL, 2002 Main Mall, Vancouver, BC, V6T IZ4

Behavioral observations of lactating Steller sea lions (Eumetopias
jubatus) and their offspring were recorded at four haulout sites in Alaska
to determine (1) whether sea lions wean during winter while they are 7 to
9 mo old and (2) whether sea lions using sites in the Gulf of Alaska (the
declining endangered population) made longer foraging trips than sea lions
in southeast Alaska (where the population appeared larger and healthier).
Longer foraging trips are commonly thought to be an indicator of
nutritional stress. Eight sets of behavioral observations were made using
focal and scan-sampling techniques at haulouts from 1995 to 1998 during
three seasons (winter, spring, and summer). Counter to expectations, we
found no significant differences between haulout populations in the time
that lactating Steller sea lions spent at sea or on shore. This suggests
that lactating sea lions did not have more difficulty capturing prey from
winter through summer in the area of decline compared to where sea lion
numbers increased. Lactating Steller sea lions in both regions did make
longer foraging trips in winter than they did in spring and summer. These
changes in foraging patterns among seasons were consistent among all years
and sites. The proportion of time that immature Steller sea lions suckled
declined through the spring to early summer, suggesting that sea lions
began supplementing their milk diet with solid food in the spring. We did
not observe any sea lions weaning during winter; rather, most appeared to
wean at the start of the breeding season when they were 1 or 2 y old. Sea
lions observed in southeast Alaska during the late 1990s while population
growth was slowing suggest that most males weaned at 2 y and that about
50% of females weaned at 1 y and the remainder at 2 y.
******************************************************** Cooper, L.W.*,
C.J. Ashjian, S.L. Smith, L.A. Codispoti, J.M. Grebmeier, R.G. Campbell,
and E.B. Sherr. Rapid seasonal sea-ice retreat in the Arctic could be
affecting Pacific walrus (Odobenus rosmarus divergens) recruitment.
Aquatic Mammals 32(1):98-102.

*Department of Ecology and Evolutionary Biology, University of Tennessee,
Knoxville, TN 37996, USA

Under conditions of rapid sea-ice retreat and dissolution, we observed at
least nine Pacific walrus calves separated from adult females in waters as
deep as 3,000 m in July and August 2004 in the Canada Basin of the Arctic
Ocean. Given limited sea surface visibility from the ship, we surmise that
many additional calves may have been separated in the overall study area.
These conditions appear to have been related to the transport of unusually
warm (7° C) Bering Sea water into this area north of Alaska. Walruses
invest considerable maternal resources while caring for calves on
seasonally ice-covered continental shelves for periods of up to 2 y or
more and only rarely separate from their young. Therefore, these
observations indicate that the Pacific walrus population may be
ill-adapted to rapid seasonal sea-ice retreat off Arctic continental
shelves.
____________________________________________________________________________
Lanyon, J.M.*, K.. Newgrain, and T. Sahir Syah Alli. 2006. Estimation of
water turnover rate in captive dugongs (Dugong dugon). Aquatic Mammals
32(1):103-108.

*School of Integrative Biology, The University of Queensland, Brisbane,
Queensland, 4072, Australia

Water turnover rate was measured for two captive dugongs (Dugong dugon)
using deuterated water. Body water content of 69.5% in a dugong was high
compared to other marine mammals. A water turnover of 257.2 ml kg−1
day−1 measured in one dugong was almost twice as high as the highest
rates measured in studies of captive West Indian manatees (Trichechus
manatus) and was high compared to those measured in carnivorous marine
mammals. The other dugong's estimated water turnover rate of 134 ml kg−1
day−1 was comparable to the highest rates in manatees. Two alternative
explanations are offered for the high water turnover: (1) the incidence of
mariposia or voluntary drinking of sea water by the dugong or (2) a
metabolic rate that is significantly higher than predicted, based on its
phylogeny.
************************************************************************
Pérez, M.J.*, F. Thomas, F. Uribe, M. Sepúlveda, M. Flores, and R.
Moraga. 2006. Fin whales (Balaenoptera physalus) feeding on Euphausia
mucronata in nearshore waters off north-central Chile Aquatic Mammals
32(1):109-113.

*Eutropia, Centro de Investigacion de Aves y Mamíferos Marinos de Chile,
Uno Poniente 960, Departmento 1102, Vina del Mar, Chile

This paper reports the presence and feeding activity of fin whales
(Balaenoptera physalus) during the austral summers of 2004 and 2005 in
coastal waters near the Reserva Nacional Pinguino de Humboldt, north of
Chile. The main prey item of the species was identified as the euphausiid
Euphausia mucronata. The presence of B. physalus is associated with a high
concentration of potential prey probably produced by an upwelling system
that is frequently detected slightly south of the study area during
summer. This information is a contribution to the knowledge of
distribution, feeding behavior, and diet of B. physalus. Additionally, it
constitutes the first record of a direct observation of feeding activity
of B. physalus along the Chilean coast.
**************************************************************************
Schusterman, R.J. 2006. Book review: Entanglements: the Intertwined Fates
of Whales and Fishermen. Author: Tora Johnson. Aquatic Mammals
32(1):114-115.

*Long Marine Laboratory, University of California at Santa Cruz, 100
Shaffer Road, Santa Cruz, CA 95060, USA
***********************************************************************
Blomqvist, C. 2006. Book review: The Encyclopedia of Animal Behavior.
Editor: Marc Bekoff. Aquatic Mammals 32(1):116-117.

*Department of Physics, Chemistry, and Biology, University of Linkoping,
SE-581 83 Linkoping, Sweden



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