Although much research has focused on marine mammal sensory systems over the last several decades, we still lack basic knowledge for many of the species within this diverse group of animals. Our conference workshop allowed all participants to present recent developments in the field and culminated in discussions on current knowledge gaps. This report summarizes open questions regarding marine mammal sensory ecology and will hopefully serve as a platform for future research.

No abstract

No abstract

In this theme issue, our multidisciplinary contributors highlight the cognitive adaptations of marine mammals. The cognitive processes of this group are highly informative regarding how animals cope with specifics of and changes in the environment, because, not only did modern marine mammals evolve from numerous, non-related terrestrial animals to adapt to an aquatic lifestyle, but some of these species regularly move between two worlds, land and sea. Here, we bring together scientists from different fields and take the reader on a journey that begins with the ways in which modern marine mammals (whales, dolphins, seals, sea lions and manatees) utilize their perceptual systems, next moves into studies of the constraints and power of individuals’ cognitive flexibility, and finally showcases how those systems are deployed in social and communicative contexts. Considering the cognitive processes of the different marine mammals in one issue from varying perspectives will help us understand the strength of cognitive flexibility in changing environments—in marine mammals and beyond.

Urbanization along marine habitat has greatly influenced species interaction. Some species thrive under these conditions, while others experience negative consequences, such as population decline or local extinction. One such example of this process has been the local extinction of pinnipeds within the New York City region. Population decline likely occurred in concurrence with increased anthropogenic activities, such as rapid industrialization and pollution of the marine ecosystem. Recently, the general public began to report anecdotal sightings of pinnipeds within the New York City waterways. Given the prevalence of potential sightings, we conducted naturalistic observations of harbor seals (Phoca vitulina) and grey seals (Halichoerus grypus) between the wintering months of 2011-2017, and along the New York City foreshore, particularly focusing on two main locations: Orchard Beach and Swinburne Island. Over this period, we monitored the demographic trend and found that seasonal populations are relatively stable and consistent from year-to-year. The results are encouraging, and demonstrate that pinnipeds are likely returning to a previously inhabited niche. Moreover, their presence may serve as bioindicators of ecosystem health. Despite continued anthropogenic activities, increasingly positive environmental conditions seem to favor a population of wintering pinnipeds. Consequently, this may have additional positive impacts on the interaction of species that share the same habitat. Overall, with urban populations increasing, there will always be contact between humans, their activities, and pinnipeds at select haul out locations. In order for populations to be sustainable, pinnipeds must negotiate local natural and artificial challenges, and adapt to dynamic conditions created by an urban environment.