Historical data on age, growth and reproduction of pygmy (Kogia breviceps) and dwarf (Kogia sima) sperm whales stranded along the Southern African coastline, with additional information from Australian specimens.

Stomach contents were analyzed of six pygmy sperm whales (Kogia breviceps) and five dwarf sperm whales (Kogia sima) which were taken as by-catch or were stranded specimens in coastal Taiwan from 1998 through 2000. Twenty-two species in 12 families of oceanic cephalopods were identified. In pygmy sperm whales, Enoploteuthis chunii, Sthenoteuthis oualaniensis, and Taonius pavo were the primary prey in the diet, while E. chunii, Histioteuthis miranda, and T. pavo were the most important prey items ingested by dwarf sperm whales. Although the primary prey items these two species ingested were very similar, each item comprised a different proportion for each whale species. A similarity test demonstrated a significant difference in prey composition, and SIMPER analysis showed that E. chunii was ranked first and contributed 37.1 % to the average dissimilarity between pygmy and dwarf sperm whales. Pygmy sperm whales fed on much larger T. pavo compared to those ingested by dwarf sperm whales, while dwarf sperm whales ingested more H. miranda than did pygmy sperm whales. These results support the view that pygmy sperm whales live seaward of the continental shelf and that dwarf sperm whales live more in coastal waters.

A complementary approach of stomach content and stable isotope analyses was used to characterize the foraging ecology and evaluate niche overlap between pygmy (Kogia breviceps) and dwarf (K. sima) sperm whales stranded on the U.S. mid‐Atlantic coast between 1998 and 2011. Food habits analysis demonstrated both species were primarily teuthophagous, with 35 species of cephalopods, and 2 species of mesopelagic fishes represented in their overall diets. Pianka's Index of niche overlap suggested high overlap between whale diets (On= 0.92), with squids from the families Histioteuthidae, Cranchidae, and Ommastrephidae serving as primary prey. Pygmy sperm whales consumed slightly larger prey sizes (mean mantle length [ML] = 10.8 cm) than dwarf sperm whales (meanML= 7.8 cm). Mean prey sizes consumed by pygmy sperm whales increased with growth, but showed no trend in dwarf sperm whales. Significant differences were not detected inδ15N andδ13C values of muscle tissues from pygmy (10.8‰ ± 0.5‰, −17.1‰ ± 0.6‰), and dwarf sperm whales (10.7‰ ± 0.5‰, −17.0‰ ± 0.4‰), respectively. Isotopic niche widths also did not differ significantly and dietary overlap was high between the two species. Results suggest the feeding ecologies of the pygmy and dwarf sperm whales are similar and both species occupy equivalent trophic niches in the region.

Pygmy and Dwarf Sperm Whales: Kogia breviceps and K. sima

The superfamily Physeteroidea includes three extant species: the sperm whale (Physeter macrocephalus), the dwarf sperm whale (Kogia sima), and the pygmy sperm whale (K. breviceps). Despite extreme difference in size between the Kogia spp. and their large Physeter relative, all three share ecological and acoustic traits relating to their deep-diving behavior and high rates of acoustic activity. All three species can be found across the Central and Western Pacific ocean, an area that has been monitored using passive acoustics (High-frequency Acoustic Recording Packages, HARPs) for more than 10 years. We identified sperm whale and Kogia spp. signals in the long-term HARP records from 13 locations across the Central and Western Pacific ocean. A combination of automated tools and human analysis were used to record detection events of both types of signals. While sperm whales were found at all 13 locations, the Kogia species (which cannot yet be distinguished acoustically) were detected at approximately half of the sites. Presence of sperm whale signals was modeled to determine if temporal parameters, such as lunar cycle and day of the year, could explain patterns of presence. Across the whole region the best model included the day of the year and the recording site, while sub-regions and site-specific models had slightly different combinations of parameters.

Chapter Two - Strandings and at sea observations reveal the canary archipelago as an important habitat for pygmy and dwarf sperm whale

Chapter Three - Records from visual surveys, strandings and eDNA sampling reveal the regular use of Reunion waters by dwarf sperm whales

Pygmy sperm whales (Kogia breviceps) and dwarf sperm whales (Kogia sima) are deep diving cetaceans that commonly strand along the coast of the southeast US, but that are difficult to study visually at sea because of their elusive behavior. Conventional visual surveys are thought to significantly underestimate the presence of Kogia and they have proven difficult to approach for tracking and tagging. An approach is presented for density estimation of signals presumed to be from Kogia spp. based on passive acoustic monitoring data collected at sites in the Gulf of Mexico (GOM) from the period following the Deepwater Horizon oil spill (2010-2013). Both species of Kogia are known to inhabit the GOM, although it is not possible to acoustically separate the two based on available knowledge of their echolocation clicks. An increasing interannual density trend is suggested for animals near the primary zone of impact of the oil spill, and to the southeast of the spill. Densities were estimated based on both counting individual echolocation clicks and counting the presence of groups of animals during one-min time windows. Densities derived from acoustic monitoring at three sites are all substantially higher (4–16 animals /1000 km2) than those that have been derived for Kogia from line transect visual surveys in the same region (0.5 animals/1000 km2). The most likely explanation for the observed discrepancy is that the visual surveys are underestimating Kogia spp. density, due to the assumption of perfect detectability on the survey trackline. We present an alternative approach for density estimation, one that derives echolocation and behavioral parameters based on comparison of modeled and observed sound received levels at sites of varying depth.

Pygmy (Kogia breviceps) and dwarf (K. sima) sperm whales are rarely seen in the wild, but often seem to live-strand, particularly in cow-calf pairs. The rehabilitation of live-stranded individuals of both species has proven to be exceedingly diffi-cult. The few released animals might not have been completely healthy, an alternative chosen due to their poor survival in captivity. The rehabilitation challenges for Kogia are numerous because limited knowledge exists regarding even the basic biology of both species. This report provides information derived from the rehabilitation of 13 live-stranded K. breviceps and K. sima (including five calves) over the last decade at the Dolphin and Whale Hospital at Mote Marine Laboratory and Aquarium in Sarasota, Florida. One K. breviceps calf survived for almost 21 months in captivity and one K. sima survived for over 15 months, both apparent world-wide records. From these cases we learned that it is critical to provide supplemental fluids in addition to solid food to maintain continuous activity of the intestinal tract, especially if maintained in chlorine-treated water, and that digestibility of squid species typically fed to captive marine mammals was poor. Both species appear to be susceptible to adverse reactions to a number of the drugs commonly used during rehabilitation. In addition, an artificial calf formula was developed to provide adequate nutri-tion for young calves. Finally, gastric and intesti-nal stasis appears to lead to death in many of these whales in captivity.Key Words: Rehabilitation, pygmy sperm whale, dwarf sperm whale, calf formula, orphan calves, survival, captivity, Kogia breviceps, Kogia sima

: Dwarf (Kogia sima) and pygmy (K. breviceps) sperm whales are among the least known species of odontocetes, despite their distribution in oceanic waters world-wide. There is some evidence that both species may be at least occasionally impacted by Navy sonar activity (Hohn et al. 2006; Weilgart 2007). The long-term goals of this research are to reduce uncertainty regarding movements and habitat use of these species in Hawaiian waters, an area where these species are exposed to Navy activities. The objectives of this research are to assess site fidelity, movements, and habitat use of dwarf and pygmy sperm whales in Hawai i over periods of weeks to months, through the remote deployment of LIMPET satellite tags. Knowledge of site fidelity and movements among islands will allow for assessment of the likelihood of repeat exposure to anthropogenic activities, as well as determination of whether individuals are part of smaller island-associated populations or open-ocean populations. The results will also help in identifying preferred habitats where overlap with anthropogenic activities is most likely to exist.

We present prevalence of Bartonella spp. for multiple cohorts of wild and captive cetaceans. One hundred and six cetaceans including 86 bottlenose dolphins (71 free-ranging, 14 captive in a facility with a dolphin experiencing debility of unknown origin, 1 stranded), 11 striped dolphins, 4 harbor porpoises, 3 Risso's dolphins, 1 dwarf sperm whale and 1 pygmy sperm whale (all stranded) were sampled. Whole blood (n = 95 live animals) and tissues (n = 15 freshly dead animals) were screened by PCR (n = 106 animals), PCR of enrichment cultures (n = 50 animals), and subcultures (n = 50 animals). Bartonella spp. were detected from 17 cetaceans, including 12 by direct extraction PCR of blood or tissues, 6 by PCR of enrichment cultures, and 4 by subculture isolation. Bartonella spp. were more commonly detected from the captive (6/14, 43%) than from free-ranging (2/71, 2.8%) bottlenose dolphins, and were commonly detected from the stranded animals (9/21, 43%; 3/11 striped dolphins, 3/4 harbor porpoises, 2/3 Risso's dolphins, 1/1 pygmy sperm whale, 0/1 dwarf sperm whale, 0/1 bottlenose dolphin). Sequencing identified a Bartonella spp. most similar to B. henselae San Antonio 2 in eight cases (4 bottlenose dolphins, 2 striped dolphins, 2 harbor porpoises), B. henselae Houston 1 in three cases (2 Risso's dolphins, 1 harbor porpoise), and untyped in six cases (4 bottlenose dolphins, 1 striped dolphin, 1 pygmy sperm whale). Although disease causation has not been established, Bartonella species were detected more commonly from cetaceans that were overtly debilitated or were cohabiting in captivity with a debilitated animal than from free-ranging animals. The detection of Bartonella spp. from cetaceans may be of pathophysiological concern.

Brucella species, a Gram-negative intracellular bacterium, is the causative agent of brucellosis, and is responsible for reproductive disorders or abortions in domesticated animals (Corbel and Brinley-Morgan 1984). It has been...

Marine mammal strandings in the New Caledonia region, Southwest Pacific

Cetaceans inhabit oceans throughout the world. Four specific odontocetes, namely Cuvier's beaked whale (Ziphius cavirostris), Indo Pacific finless porpoise (Neophocaena phocaenoides), pygmy sperm whale (Kogia breviceps), and dwarf sperm whale (Kogia sima), have occasionally been found stranded along Thailand's coastal waters (the Andaman Sea and the Gulf of Thailand). Although shared haplotypes of each species for many locations have been found, and some species have revealed genetic structure through haplotype networks, cetaceans in Thai waters have never been investigated in terms of comparing haplotypes to those that have existed before. Herein, we have illustrated the matrilineally phylogeographic relationships among worldwide populations through Bayesian Phylogenetic tree computations using Markov Chain Monte Carlo (MCMC) and Median-Joining Networks (MJNs). Unique haplotypes of the control region mitochondrial DNA of Thai odontocetes were found for all species. Moreover, a high degree of worldwide haplotype diversity (hd) above 0.8 among the four species was detected, while the lowest degree of nucleotide diversity (π) was observed in the Indo Pacific finless porpoise (1.12% ± 0.184%). An expansion of the effective female population size worldwide of three odontocete species was detected using Bayesian Skyline Reconstruction, but this did not include the Indo Pacific finless porpoise. Because Thai seas are located within the Indo Polynesian province, where this biodiversity hotspot exists, we speculate that these odontocetes may also inhabit specific habitats within the Malay Peninsula and Thailand's territorial waters. Therefore, closer attention and monitoring of these cetacean populations will be necessary for future conservation efforts.

Monitoring large marine mammals is challenging due to their low abundances in general, an ability to move over large distances and wide geographical range sizes.The distribution of the pygmy (Kogia breviceps) and dwarf (Kogia sima) sperm whales is informed by relatively rare sightings, which does not permit accurate estimates of their distribution ranges. Hence, their conservation status has long remained Data Deficient (DD) in the Red list of the International Union for Conservation of Nature (IUCN), which prevent appropriate conservation measures.Environmental DNA (eDNA) metabarcoding uses DNA traces left by organisms in their environments to detect the presence of targeted taxon, and is here proved to be useful to increase our knowledge on the distribution of rare but emblematic megafauna.Retrieving eDNA from filtered surface water provides the first detection of the Dwarf sperm whale (Kogia sima) around the remote Malpelo island (Colombia).Environmental DNA collected during oceanic missions can generate better knowledge on rare but emblematic animals even in regions that are generally well sampled for other taxa.

Pygmy and Dwarf Sperm Whales: Kogia breviceps and K. sima