Integrating cultural dimensions in sperm whale (Physeter macrocephalus) conservation: threats, challenges and solutions

Abstract

Culture-socially transmitted behaviours shared within a community-can influence animal populations' structure, vulnerability and resilience. Clans of sperm whales in the Eastern Tropical Pacific (ETP) exemplify the profound influence of culture on these dynamics and highlight the challenges of accounting for culture in conservation efforts. Globally, sperm whales are classified as vulnerable, and the ETP sperm whale population has struggled to reach a positive growth rate. This stagnation is partly due to cumulative anthropogenic threats in the region, including fishing conflicts, vessel traffic, pollution, deep sea mining, oil and gas exploration, and anthropogenic climate change. The United Nations Convention on Migratory Species adopted a Concerted Action for ETP sperm whales in 2017, proposing collaborative efforts to address cultural dimensions in conservation. However, knowledge gaps and real-world implementation challenges persist. Here, we review the role of social transmission in shaping sperm whale behaviour and populations, outline current anthropogenic threats and environmental stressors they face in the ETP, and discuss the ongoing challenges of incorporating cultural dimensions into large-scale international conservation efforts. Strengthening transnational collaboration and capitalizing on new technologies for efficient analysis can help bridge these knowledge gaps and enhance future research on this iconic species.This article is part of the theme issue 'Animal culture: conservation in a changing world'.

Keywords: Eastern Tropical Pacific; anthropogenic threats; behaviour; conservation; social transmission; sperm whale clans.

Figure 1.

Multi-level social structure of sperm whales. Females and juvenile whales form nearly permanent social units (coloured ellipses) that can create temporary groups (dashed ellipses), usually with social units with which they share a significant portion of their coda repertoires, forming vocal clans (coloured rectangles) within the same geographic region (black rectangle). Schematic adapted from Cantor et al. [20].

Figure 2.

Risk maps for sperm whales in the ETP. (A) Cumulative risk estimated as the intersection between threats documented between 1991 and 2024 and the modelled core habitat of the species. Red cells show areas of high risk where at least three threats were detected per cell (N threats = 5; AquaMaps presence probability threshold ≥ 0.6). The blue region represents the core sperm whale habitat where no threats have been documented. (B–F) Threat-specific risk maps for (B) fisheries interactions, (C) vessel traffic, (D) pollution, (E) oceanographic and environmental changes and (F) direct kills. Tan cells show where each threat has been documented, and blue cells show the core sperm whale habitat, where a specific threat was not documented. Adapted and updated from Avila et al. [36].

Figure 3.

Distribution map of Eastern Pacific sperm whales. (A) Current sperm whale native home range distribution map. (B) Projected sperm whale native home range distribution map for 2050 under the RCP8.5 climate change scenario. The RCP8.5 is a representative concentration pathway (RCP) where greenhouse gas emissions continue escalating to the highest concentration in the absence of effective climate change policies, resulting in a 4.3°C temperature rise by 2100 [39,40]. The scale bar shows the relative probability of occurrence of sperm whales, ranging from 0.01−0.19 (i.e. light yellow) to 0.80−1.0 (i.e. red), standing for 1.0−20% and 80−100% probability of occurrence. Maps were computer generated and adapted from AquaMaps (2019) online (i.e. for P. macrocephalus (https://www.sealifebase.ca/summary/Physeter-macrocephalus.html) with modelled year 2050 native range map based on IPCC RCP8.5 emissions scenario; https://www.aquamaps.org).