Apologies to those of you who will receive duplicate emails due to cross-posting. The following are abstracts from the most recent issue (Volume 36, issue 2, 2010) ofAquatic Mammals.

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Baleen whales have among the lowest reproduc tive rates in the animal kingdom, coupled with high energetic demands on lactating mothers to support the rapid growth of their offspring. Because each offspring represents a large portion of a female’s reproductive effort, strong selec tion pressure should be in place to minimize the potential for misplaced parental effort. However, we describe a case in which two North Atlantic right whale (Eubalaena glacialis) offspring were switched between mothers and remained with their “adopted” mothers throughout their first year of life (until they were weaned). The most reason able explanation is that this swap was an accident caused by the females calving in close spatial and temporal proximity. The calves likely associated with the wrong mothers before any mother-off spring recognition system had developed, and an association then formed between these non-bio logical mother-offspring pairs. These data raise intriguing questions regarding how often this may occur in other wildlife populations, what mecha nisms are used for mother-offspring recognition in whales, and how long it takes for this recognition to develop.

When two species share a common habitat, interspecific interactions can take many forms. Understanding the dynamics of these interactions can provide insight into the behavior and ecology of those species involved. Two separate, unusual interactions are described in which a humpback whale (Megaptera novaeangliae) lifted a bottle-nose dolphin (Tursiops truncatus) completely out of the water. Both incidents occurred in Hawaiian waters. Based on reports of object play by hump-back whales, and the apparent initiation and coop-eration of each dolphin being lifted, object (i.e., the dolphin) play by the whale and social play by the dolphin seem to be the most plausibleexplana-tions for the interaction. Aggressive and epimeletic behavior by the humpback were also considered.

Pinnipeds prey primarily on fish and invertebrates; however, several species are known to prey upon other pinniped species. Herein, we document an observation of aSteller sea lion (Eumetopias juba-tus) attacking and partially consuming a juvenile harbor seal (Phoca vitulina richardii) in Johns Hopkins Inlet in Glacier Bay National Park, Alaska. Population trends for Steller sea lions and harbor seals contrast dramatically in the Glacier Bay region. Although other marine predators are known to attack harbor seals, it is possible that Steller sea lions could potentially have both a direct and indi-rect influence on harbor seals in the Glacier Bay region.

Lactation is the most energetically expensive aspect of mammalian reproduction. As capital breeders, lactating southern right whales (Eubalaena aus-tralis) are completely dependent on their stored nutrients. The relative proportion of different endogenous nutrient pools used during lacta-tion could be assessed using stable isotopes. We determined the stable carbon and nitrogen isotope difference between skin samples of 42 southern right whale mothers and their calves. The mean δ15N value of calves was 0.51‰ higher than that of their mothers, but their δ13C values were identical. However, when analyzed by year, the mother-calf pairs showed no isotope differences in 2004, but calves had higher δ15N (0.85‰) and δ13C (0.63‰) in 2003 and 2005. We hypothesize that the inter-annual variability was a consequence of different levels of nutritional stress. A decline in food abun-dance prior to the nursing seasons could result in mothers with relatively poorer physical condition that would not be able to meet the high energetic demands of their offspring. Thus, the calves would be forced to utilize proteins as well as lipids to meet this demand, increasing their nitrogen and carbon isotope ratios. This hypothesis is supported by an independent assessment of the proportion of stranded whales over the same time period.

Manatees (Trichechus manatus latirostris) in Florida utilize intake and effluent canals of power plants as resting and thermoregulatory habitat. We report the use of a power plant canal in Cuba by a known Florida manatee, the first documented case of movement by a manatee between Florida and Cuba. In January, February, and April 2007, two manatees (mother and calf) were reported enter ing a power plant canal in north Havana, Cuba. The larger manatee had several distinctive scars which were photographed. Digital images were matched to a previously known Florida mana tee (CR131) with a sighting history dating from December 1979 to July 2006. Exchanges of individuals between Florida and Cuba may have important genetic implications, particularly since there appears to be little genetic exchange between the Florida manatee subspecies with populations of the Antillean manatee subspecies (T. m. mana tus) in Puerto Rico and the Dominican Republic.

A cetacean line-transect survey was conducted in the eastern Caribbean Sea and the adjacent southwestern North Atlantic Ocean from 17 April to 14 May 2004 to obtain information on ceta-cean distribution and density. The survey area was divided into coastal and offshore blocks; the coastal blocks contained the insular continen-tal shelf. A total of 2,273 nmi (4,210 km) was searched (1,528 nmi [2,830 km] in coastal blocks and 745 nmi [1,380 km] in offshore blocks) with 76 cetacean sightings (64 and 12 for the coastal and offshore blocks, respectively). Twelve species were identified (number of individuals/groups observed in coastal blocks-offshore blocks): 4/4(2/2)Bryde’s whale (Balaenoptera edeni), 7/5(2/1) humpback whale (Megaptera novaeangliae), 5/5(0/0) sperm whale (Physeter macrocephalus), 32/3(0/0) short-finned pilot whale (Globicephala macrorhynchus), 132/4(0/0) melon-headed whale (Peponocephala electra), 1/1(0/0) Risso’s dolphin (Grampus griseus), 42/6(0/0) bottlenose dolphin (Tursiops truncatus), 30/1(0/0) Fraser’s dolphin (Lagenodelphis hosei), 505/9(33/3) pantropical spotted dolphin (Stenella attenuata), 35/1(35/1) Atlantic spotted dolphin (S. frontalis), 35/1(0/0) spinner dolphin (S. longirostris), and 90/1(0/0) striped dolphin (S. coeruleoalba). Additionally, 28 groups were sighted for which the species could not be identified: 5/5(2/2) large whales, 11/5(0/0) Mesoplodon spp., 1/1(0/0) ziphiid whale, 5/1(0/0) Stenella spp., and 39/11(10/3) dolphins. Due to the low number of sightings on account of the poor sighting conditions during the survey, abun dance of cetaceans could not be estimated.

The measurement of steroid hormones (e.g., andro gens, estrogens, progestins, and glucocorticoids) in alternative matrices (e.g., feces, urine, blubber, saliva, blow, milk, and ocular secretion) has been increasingly used in research with aquatic mam mals. The aim of this review is to briefly summa rize studies using steroid analysis in alternative matrices from captive and free-ranging aquatic mammal species. The analysis of steroid hor mones from alternative matrices is a powerful tool to obtain information about reproductive biology and social behavior in free-ranging aquatic mam mals, as well as to help in the management of cap tive animals. However, for a consistent monitoring of steroid hormones in alternative matrices, it is of crucial importance to verify if a chosen matrix and assay reliably reflects physiologic events.

The stomach contents from a female Longman’s beaked whale (Indopacetus pacificus), which stranded on the coast of Kagoshima Prefecture, Kyushu, Japan, were examined. This is the first specimen of this species from Japan and also its northern-most record. The remains collected from the stomach consisted of numerous cephalopod beaks and lenses and a large number of uniden-tified nematodes. Ninety-nine upper beaks and 69 lower beaks from squid species were col-lected from the stomach. The lower beaks were used to identify squid prey species; five species were identified: Taonius pavo, Onykia loennbergi, Onychoteuthis borealijaponica,Chiroteuthis pic-teti, and Histioteuthis inermis. Taonius pavo was the most common species and accounted for 84% of the total beaks. Distribution data for these squid species suggest that this whale fed in the epipe-lagic to mesopelagic zones in the western North Pacific off the southern part of Japan. Stomach morphology was also examined. The presence of a main stomach with three connecting cham-bers and one pyloric stomach compartment was confirmed. It appears that the morphology of this species’ stomach is similar to that found in Tasmacetus and Ziphius. This is the first report on the food habits, stomach anatomy, and parasites of Longman’s beaked whale and contributes to a better understanding of their biology.

Toxic (e.g., Hg, Ag, Cd, and Pb) and essential (e.g., Se, Cu, and Fe) trace element levels were determined in liver samples from four seal species (harp seal [Phocagroenlandica], n = 35; hooded seal [Cystophora cristata], n = 7; harbor seal [Phoca vitulina], n = 34; gray seal [Halichoerus grypus], n = 10) stranding in Long Island waters between 1988 and 2004 to examine temporal and species-specific patterns in these top marine car-nivores. There was no obvious trend in trace metal burdens in seal livers over this time period. Harp and hooded seals are arctic species that have only appeared in Long Island waters in recent years. Their diets are believed to include more inverte-brate prey, and this was reflected in significantly higher cadmium (Cd) concentrations (mean = 5.5 to 6.3 μg g-1 dry weight vs. 0.5 to 1.4 μg g-1 for harbor and gray seals, p = 0.007). The highest mercury (Hg) burdens (> 100 μg g-1 dry weight) were seen in seven of the eight adult harbor seals and the only adult gray seal; four of five adult harp seals did not show elevated levels. This suggests that migratory harp seals are feeding on prey with a lower Hg burden compared to resident harbor seals that forage in the coastal environment. Copper (Cu) levels were high (70 to 105 μg g-1) in a few juvenile harbor seals as predicted based on Cu-incorporating enzymes essential for growth. A few elevated silver (Ag) values (1.5 to 3.0 μg g-1) were seen in the same adult harbor seals with high Hg burdens. These values may not reflect metal burdens in healthy populations as our samples were obtained from stranded animals, but there was no evidence that any of these seals died as a result of metal toxicity.

Global pinniped distribution is greatly determined by changes in sea surface temperature. El Niño events also have been reported to directly influence pinniped distribution. These events have increased in frequency and intensity changing the foraging ecology of the two pinniped species analyzed. In this paper, we present new extralimitalrecords of distribution of two species rarely found in Mexican waters: the Galapagos (Zalophus wolle‑baeki) and the Northern (Eumetopias jubatus) sea lions. Three adultZ. wollebaeki were found in Chiapas, and one E. jubatus was recorded off the coasts of Colima—both exceeding the maximum reported extralimital distance. These new records increase the number of marine mammal species recorded in Mexico and add evidence to the fact that large-scale climatic variation and possible effects of global warming shift the distribution of marine mammals.

I. N. Visser, J. Zaeschmar, J. Halliday, A. Abraham, P. Ball, R. Bradley, S. Daly, T. Hatwell, T. Johnson, W. Johnson, L. Kay, T. Maessen, V. McKay, T. Peters, N. Turner, B. Umuroa, & D. S. Pace: First Record of Predation on False Killer Whales (Pseudorca crassidens) by Killer Whales (Orcinus orca). Aquatic Mammals 2010,36(2), 195-204, DOI 10.1578/AM.36.2.2010.195

The first record of killer whale (Orcinus orca) pre-dation on false killer whales (Pseudorca crassi-dens) is reported here. On 25 March 2010, a group of 50 to 60 false killer whales, including approxi-mately 15 calves and accompanied by three to five bottlenose dolphins (Tursiops sp.), were sighted in the Bay of Islands, New Zealand. Within 30 min, they were approached by a group of approximately eight killer whales. Five false killer whales were attacked, with at least three rammed from below, forcing them out of the water. After 29 min, the killer whales were milling at the surface and feed-ing on the carcass of a false killer whale calf, pos-sibly the only individual killed. The killer whales had prolific fresh and healed oval wounds, which were attributed to cookie cutter shark (Isistius sp.) bites.

Kathleen M. Dudzinski, Ph.D.

Editor, Aquatic Mammals Journal

Director, Dolphin Communication Project

kathleen@dcpmail.org

aquaticmammals@gmail.com

www.dolphincommunicationproject.org

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