# Three months journeying of a Hawaiian monk seal

**Authors:** David R. Brillinger, Brent S. Stewart, Charles L. Littnan  
**arXiv:** [0805.3019](https://arxiv.org/abs/0805.3019)  
**Date:** 2008-05-20  
**Summary page:** https://www.summarizepaper.com/en/arxiv-id/0805.3019v1/

## Key points

- Hawaiian monk seals are critically endangered marine mammals endemic to the Hawaiian Islands
- Their population has been declining due to various factors, including poor juvenile survival linked to inadequate foraging success
- Recent data have been collected on their foraging habitats, movements, and behaviors throughout the Northwestern and main Hawaiian Islands
- A study focused on exploring a dataset collected from a relatively shallow offshore submerged bank called Penguin Bank in search of a model for a seal's journey
- The researchers fit a stochastic differential equation (SDE) that mimics some aspects of the behavior of seals by working with location data collected for one seal
- Synthetic plots generated using the model were employed to assess its reasonableness spatially and temporally
- One notable aspect was that the animal stayed mainly southwest of Molokai during its three-month-long journey
- This work led to an estimation of the lengths and locations of the seal's foraging trips
- Findings provide valuable insights into understanding how these endangered animals behave in their natural habitat, which can help inform conservation efforts aimed at protecting them from further decline.

## Summary

Hawaiian monk seals (Monachus schauinslandi) are a critically endangered species of marine mammal that is endemic to the Hawaiian Islands and lives entirely within the jurisdiction of the United States. With only around 1300 individuals remaining, their population has been declining due to various factors, including poor juvenile survival linked to inadequate foraging success. To better understand their behavior and movements, recent data have been collected on the foraging habitats, movements, and behaviors of monk seals throughout the Northwestern and main Hawaiian Islands. This study focuses on exploring a dataset collected from a relatively shallow offshore submerged bank called Penguin Bank in search of a model for a seal's journey. The researchers fit a stochastic differential equation (SDE) that mimics some aspects of the behavior of seals by working with location data collected for one seal. The SDE is found by developing a time-varying potential function with two points of attraction. Interpreting this data was challenging as the times of location were irregularly spaced and not close together geographically. Synthetic plots generated using the model were employed to assess its reasonableness spatially and temporally. One notable aspect was that the animal stayed mainly southwest of Molokai during its three-month-long journey. This work led to an estimation of the lengths and locations of the seal's foraging trips. Their findings provide valuable insights into understanding how these endangered animals behave in their natural habitat, which can help inform conservation efforts aimed at protecting them from further decline.