https://doi.org/10.1007/s13280-024-02017-4

Because climate change and the biodiversity crisis are driven by human actions, determining psychological mechanisms underpinning support for environmental action is an urgent priority. Here, we experimentally tested for mechanisms promoting conservation-related motivation and behavior toward a flagship species, wild Tamanend's bottlenose dolphins. Following evidence that empathy increases prosocial motivations and behavior, and that the ability to identify individual humans promotes empathy, we tested whether this relationship applied to the ability to identify individual dolphins. Participants identified dolphins from their dorsal fins at above chance levels, and better individuation correlated with higher empathy for dolphins and higher willingness to pledge environmental behaviors. Pairing a narrative with an image of an injured dolphin leads to higher donations relative to a narrative alone. Our novel finding that the ability to individually identify dolphins relates to empathy and conservation-related behavior suggests pathways for strengthening environmental attitudes and behavior.

https://doi.org/10.1101/2023.12.01.569646

Dolphin morbillivirus has caused mass mortalities in dolphin populations globally. Given their role as ecosystem sentinels, mass mortalities among these populations can be detrimental. Morbillivirus is transmitted through respiratory droplets and occurs when dolphins breathe synchronously, a variable social behavior. To assess the role of variable social behavior on disease risk empirically, we collected behavioral data from wild bottlenose dolphins (Tursiops erebennus), develop network models that synthesize transmission contacts, and use an epidemiological model to predict disease consequences. We find that juveniles have more contacts than adults, adult males have more contacts than adult females, and that individuals preferentially contact others in their own demographic group. These patterns translate to higher infection risk for juveniles and adult males, which we validate using data from a morbillivirus outbreak. Our work characterizes the impact of bottlenose dolphin social dynamics on infectious disease risk and informs the structure of vulnerability for future epizootics.

https://doi.org/10.1111/mms.13022

Barnacles can reveal much about the physiology, health, and spatial ecology of their cetacean hosts. Here, we examine how temperature and hydrodynamic factors impact presence of Xenobalanus globicipitis, a pseudo-stalked barnacle that attaches exclusively to cetaceans. We hypothesized that temperature is a key environmental factor (i.e., water temperature) and physiological factor, in that X. globicipitis prefers the warmest skin temperature for attachment, possibly as a mechanism for survival in colder waters. First, we demonstrate a global relationship between spatial ecology of host species and presence of X. globicipitis. Notably, X. globicipitis is absent in the four species occupying waters with the lowest sea surface temperature (SST) year-round, but present in migratory species that likely acquire the barnacle in waters with higher SST. Second, barnacle attachment location on common bottlenose dolphin (Tursiops truncatus) dorsal fins corresponds with fin temperature and hydrodynamics. Although body temperature may influence attachment location on the body of the animal, hydrodynamic forces, as previously proposed, determine how well barnacles can remain attached during the adult stage. X. globicipitis prevalence likely provides important bioindicator, ecological, and physiological information about its host. As parasitic infestation has some cost, these results have implications for cetacean health in warming seas.

https://doi.org/10.1007/978-3-031-35651-3_10

Infanticide by adult males is a striking example of sexual conflict; males can increase their reproductive success by killing an unrelated infant and accelerating the mother’s return to breeding condition. Reports of infanticide in cetaceans have quadrupled in the past decade, and infanticide has now been documented in six species of toothed whale, including multiple populations of common bottlenose dolphins (Tursiops truncatus). Evidence of infanticide in these species is consistent with the sexual selection hypothesis; perpetrators are predominantly adult males and targets are neonates. Toothed whales have long lactation periods that suppress estrus, making infanticide potentially adaptive for adult males. However, it remains unclear if infanticidal males are likely to sire the mother’s subsequent offspring. Here, we provide an overview of infanticide in cetaceans, evaluate the evidence for the sexual selection hypothesis, and propose a framework to predict infanticide risk in this clade. Toothed whales do not typically have dominance hierarchies, stable social groups, or monopolizable mating opportunities, all hallmarks of infanticide risk in terrestrial species. Instead, we hypothesize that infanticide risk in toothed whales is modulated by encounter rates with unfamiliar males.

• Collier, M., Bansal, S., Mann, J., Foroughirad, V., Jacoby, A. 2023. Dolphins in sync: Quantifying infectious disease risk by characterizing and comparing empirical contact network structure. Network Science Society, Vienna, Austria, July.

• Collier, M.,  Jacoby, A., Foroughirad, V., Mann, J., Bansal, S. 2023 Characterizing infectious disease risk in a sentinel marine mammal with social behavior data. Animal Behavior Society, Portland, OR, July 11-15.

• Smith, P., Mann, J., Marsh, A. 2023. Wildlife empathy: the importance of the individual. American Psychological Association, Washington, DC.

• Collier, M., Mann, J., Ali, S. Bansal, S. 2022. Modeling the impacts of human disturbance in cetaceans and pinnipeds: Do behavioral changes translate to disease consequences? 24th Biennial Conference on the Biology of Marine Mammals, Palm Beach, FL, August.

• Dolezal, M., Foroughirad, V., Jacoby, A., Collier, M., Murphy, C., Fish, F., Mann, J.  2022. Some like it hot: Physiological and ecological factors in Xenobalanus globicipitis attachment to cetaceans. 24th Biennial Conference on the Biology of Marine Mammals, Palm Beach, FL, August.

• Jacoby, A., Collier, M., Wallen, M., Patterson, E.M., Mann, J. 2019. Bottlenose Dolphins (Tursiops truncatus) in the Potomac River and Chesapeake Bay, USA, World Marine Mammal Conference, Barcelona, Spain, December.

• Jacoby, A., Collier, M., Wallen, M., Patterson, E.M., Mann, J. 2019. Updated findings on bottlenose dolphins (Tursiops truncatus) in the Potomac River and Chesapeake Bay area. Southeast and Mid-Atlantic Marine Mammal Symposium (SEAMAMMS), Washington, DC, March 29-31.

• Mann, J., Jacoby, A.M., Wallen, M. M. and Patterson, E.M. 2017. The Potomac-Chesapeake Dolphin Project: preliminary findings and future directions. Southeast and Mid-Atlantic Marine Mammal Symposium (SEAMAMMS), Beaufort, NC, April 7-9.

• Urian, K., Fauquier, D. Barco, A. S., Clark, K., Doshkov, P., Engelhaupt, A., Gorgone, A., Mann, J., McFee, W., McLellan, W. A., Pabst, A., Read, A., Rittmaster, K., Sayigh, L., Silva, D., Speakman, T., Taylor, J., Thayer, V. Toth, J. and Young, R. 2017. Determining the stock identity of stranded bottlenose dolphins (Tursiops truncatus) from the unusual mortality event using the mid-Atlantic bottlenose dolphin catalog (MABDC). SEAMAMMS, Beaufort, NC, April 7-9.

• Urian, K., Horstman, S., Fauquier, D.,  Northeast and Southeast Atlantic Marine Mammal Stranding Network, Barco, S., Clark, K., Doshkov, P., Engelhaupt, A., Gorgone, A., Mann, J., McFee, W., McLellan, W., Pabst, A., Read, A., Rittmaster, K., Rowles, T., Sayigh, L., Silva, D., Speakman, T., Sullivan, J., Taylor, J., Thayer, V., Toth, J., Young, R. 2017. Images of the dead: photo-identification of stranded bottlenose dolphins yields critical information on life history, fishery interactions and unusual mortality events. 22nd Biennial Conference on the Biology of Marine Mammals, Halifax, Nova Scotia, October 22-27.