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Three months journeying of a Hawaiian monk seal

David R. Brillinger, Brent S. Stewart, and Charles L. Littnan

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Hawaiian monk seals (Monachus schauinslandi) are endemic to the Hawaiian Islands and are the most endangered species of marine mammal that lives entirely within the jurisdiction of the United States. The species numbers around 1300 and has been declining owing, among other things, to poor juvenile survival which is evidently related to poor foraging success. Consequently, data have been collected recently on the foraging habitats, movements, and behaviors of monk seals throughout the Northwestern and main Hawaiian Islands.

Our work here is directed to exploring a data set located in a relatively shallow offshore submerged bank (Penguin Bank) in our search of a model for a seal’s journey. The work ends by fitting 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. The times of location are irregularly spaced and not close together geographically, leading to some difficulties of interpretation. Synthetic plots generated using the model are employed to assess its reasonableness spatially and temporally. One aspect is that the animal stays mainly southwest of Molokai. The work led to the estimation of the lengths and locations of the seal’s foraging trips.

Chapter information

Deborah Nolan and Terry Speed, eds., Probability and Statistics: Essays in Honor of David A. Freedman (Beachwood, Ohio, USA: Institute of Mathematical Statistics, 2008), 246-264

First available in Project Euclid: 7 April 2008

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Zentralblatt MATH identifier

Primary: 60J60: Diffusion processes [See also 58J65] 62G08: Nonparametric regression 62M10: Time series, auto-correlation, regression, etc. [See also 91B84] 70F99: None of the above, but in this section

bagplot boundary GPS locations Molokai Monachus schauinslandi Hawaiian Monk seal moving bagplot potential function robust methods simulation spatial locations stochastic differential equation synthetic plot UTM coordinates

Copyright © 2008, Institute of Mathematical Statistics


Brillinger, David R.; Stewart, Brent S.; Littnan, Charles L. Three months journeying of a Hawaiian monk seal. Probability and Statistics: Essays in Honor of David A. Freedman, 246--264, Institute of Mathematical Statistics, Beachwood, Ohio, USA, 2008. doi:10.1214/193940307000000473.

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