P. B. Best

Bio: P. B. Best is an academic researcher. The author has contributed to research in topics: Whale & Cetacea. The author has an hindex of 1, co-authored 1 publications receiving 78 citations.

Distribution and population separation of Bryde's whale Balaenoptera edeni off southern Africa

Abstract: A review of available catch and biological data suggests that there are 3 populations of Bryde's whales in the southern African region. An inshore population (the South African Inshore Stock) occurs over the continental shelf of South Africa, south of about 30° S, and seems to be non- migratory, although there is a movement up the west coast in winter. A pelagic population (the South- east Atlantic Stock) occurs on the west coast of southern Africa, ranging from equatorial regions to about 34° S, and appears to migrate north in autumn and south in spring. Whales from the Southeast Atlantic Stock differ from the South African Inshore Stock in size, scarring, baleen shape, seasonality of reproduction, fecundity and prey types. Both occurred in the west coast whaling ground off Donkergat, but with differing seasonalities and distributions from the coast. Bryde's whales are rare on the east coast of southern Africa, but are found in summer in some numbers south of Madagascar. Whales from this population are clearly smaller than those from the Southeast Atlantic Stock, but are similar in size to, or even smaller than, those from the South African Inshore Stock. Their external appearance is unknown, but they differ in prey type from the South African Inshore Stock, and because of a clear discontinuity in distribution it is believed that they form a third (pelagic) popula- tion (the Southwest Indian Ocean Stock). This population may or may not move north as far as the Seychelles in winter, but seems to be separate from Bryde's whales in the Arabian Sea. From their size composition, length at sexual maturity and infrequent capture, Bryde's whales taken at Durban may have represented strays from either the South African Inshore Stock or the Southwest Indian Ocean Stock, and recorded stomach contents also indicate prey types common to either stock. The unusual degree of population differentiation shown by Bryde's whales may be a consequence of their limited seasonal migrations and apparent resource partitioning.

Barnacle reproductive hotspots linked to nearshore ocean conditions

Abstract: Coastal marine ecosystems provide important ecosystem services to human populations worldwide. Understanding the contexts in which a species has markedly higher reproductive output is vital for effective management and conservation of these valuable and highly impacted systems. We documented reproductive hotspots along the Oregon coast for an ecologically significant marine invertebrate, the intertidal barnacle Balanus glandula. Greater larval production in both natural and experimental populations was associated with higher primary productivity in the adjacent nearshore ocean, providing strong evidence for bottom-up forcing. Mean cumulative larval production per 100 cm2 in natural barnacle populations in the region of higher primary productivity was almost 5x that of populations in the less productive region. Mean estimated larval production per individual in experimental populations in the region of higher primary productivity was >2x that of populations in the region of lower productivity, and mean larval production per 100 cm2 was >120x greater in the region of higher productivity. Our results highlight the importance of spatial heterogeneity in reproduction and other ecological processes in the marine environment and provide a mechanistic basis for evaluating the relative contributions of different sites when designing marine reserves and other protected areas. Our findings also advance the understanding of the role of bottom-up influences on population and community dynamics and contribute data for the next generation of models of marine community dynamics.

White Sharks (Carcharodon carcharias) Scavenging on Whales and Its Potential Role in Further Shaping the Ecology of an Apex Predator

Abstract: Scavenging, a result of a temporary pulse of resources, occurs in virtually all ecosystems containing carnivores, and is an important energy transfer pathway that can impact ecosystem structure and function, and this ecological significance has largely been considered from a terrestrial standpoint; however, little is known about the role of scavenging in shaping the behavioral ecology of marine species, specifically apex predators. Here we present findings from multiple opportunistic observations of white sharks scavenging on whale carcasses in False Bay, South Africa. Observations of white sharks scavenging over successive days provided evidence of strategic and selective scavenging by this species. Moreover, extended daily observations permitted recordings of unique social, aggregative, and feeding behaviors. We further compare these data against observations of natural predation by sharks on seals in the study area. We discuss these data in relation to environmental conditions, shark social interactions, migration patterns, whale biology, and behaviorally-mediated trophic cascades. While the appearance of a whale carcass is largely a stochastic event, we propose that white shark scavenging on whales may represent an underestimated, yet significant component to the overall foraging ecology of this species, especially as individuals attain sexual maturity.

Mysticete migration revisited: are Mediterranean fin whales an anomaly?

Abstract: The generally accepted model of Mysticete whale migration is that most individuals undertake seasonal migrations between high and low latitudes. Although numerous exceptions have been described in the literature, the traditional model remains unexamined. This paper represents the first ‘official’ challenge to the traditional model of Mysticete migration. We set out to review the current state of knowledge on the Mediterranean fin whale migratory pattern, and to examine whether the small, resident population in the Mediterranean is an anomaly within the framework of the traditional model of Mysticete migration. We investigated the prevalence of alternative migratory strategies among the Mysticete whales, reviewing the migratory habits of the Mediterranean fin whales and those of other fin whale and baleen whale populations. We reach three main conclusions. First, the seasonal behaviour of the resident Mediterranean fin whales is highly dynamic, and a decade of research has not clarified prevailing uncertainties regarding migration patterns. Second, migration strategies similar to those observed in the Mediterranean fin whales are commonly seen in other populations of baleen whales. Third, the traditional model of whale migration is too simplified to describe the repertoire of Mysticete migratory behaviours accurately. We argue that the paradigm of baleen whale migration warrants further scrutiny to account for more complex movement strategies. We suggest that Mysticete migration should be thought of as a continuum of different strategies that have evolved in the face of different selective pressures. Instead of representing an exception to the rule, the resident Mediterranean fin whales may in fact fall towards one end of a larger spectrum of migratory behaviours. A greater knowledge of ecological factors, reproductive patterns, and local adaptations will be needed to understand the evolutionary mechanisms behind the diversity of migratory habits.

A review of cetacean occurrence in West African waters from the Gulf of Guinea to Angola

Abstract: The cetacean fauna of the west coast of Africa is poorly described. Therefore, literature on the occurrence of cetacean species in the waters of 13 potential West African range states from the Gulf of Guinea to Angola was reviewed, including sighting, stranding, capture, bycatch and whaling records. 2. At least 28 species of cetacean were documented in the study region, comprising seven baleen whale species and 21 species of toothed whale (including at least 17 delphinid species). 3. Cetaceans could be broadly split into seven ecological categories, based on their distribution. A warm temperate/tropical deep-water cetacean community domi- nated the study area. Cooler water from the Benguela Current influenced southern Angola (16°S latitude) and at least three cetacean species occurred predominantly in this region. 4. Only three or fewer species were confirmed in the waters of Togo, Nigeria, Cameroon and the Democratic Republic of Congo. Seventeen or more species were documented in Ghana, Gabon and Angola, where dedicated cetacean research projects have been initiated in recent years. Angola had the most diverse docu- mented cetacean community: 28 confirmed species. 5. The humpback whale Megaptera novaeangliae was the most widely recorded species, and was documented in 11 (85%) countries. Sperm whales Physeter macro- cephalus, Bryde's whales Balaenoptera cf. brydei, bottlenose dolphins Tursiops trun- catus and Atlantic spotted dolphins Stenella frontalis were recorded in over half of the countries.