Risso's dolphins alter daily resting pattern in response to whale watching at the Azores

Fleur Visser, Karin L. Hartman, Ente J. J. Rood, Arthur J. E. Hendriks, Daan B. Zult, Wim J. Wolff, Jef Huisman, Graham J. Pierce

Research output: Contribution to journalArticle

28 Citations (Scopus)
2 Downloads (Pure)

Abstract

Behavioral responses of Risso's dolphins (Grampus griseus) to whale watching vessels were studied off Pico Island, Azores. Dolphin behavior was studied from a land-based lookout, enabling observations of groups in the absence and presence of vessels. The number of whale watching vessels showed a clear seasonal pattern, dividing the whale watching period into a low season and a high season. During the low season, Risso's dolphins rested mainly in the morning and afternoon. During the high season, Risso's dolphins rested less and did so mainly at noon, when the number of active vessels was lowest. Data analysis using a generalized additive mixed model indicated that this change in resting behavior was associated with vessel abundance. When more than five vessels were present, Risso's dolphins spent significantly less time resting and socializing. During the high season, this vessel abundance was exceeded during 20% of observation days. While we cannot be sure that the observed changes in behavior have fitness consequences for Risso's dolphins, reduced resting and socializing rates can have negative impacts on the build-up of energy reserves and on reproductive success. We suggest the adoption of precautionary management measures to regulate the timing and intensity of whale watching activities.

Original languageEnglish
Pages (from-to)366-381
Number of pages16
JournalMarine Mammal Science
Volume27
Issue number2
Early online date15 Jul 2010
DOIs
Publication statusPublished - Apr 2011

Keywords

  • Risso's dolphin
  • Grampus griseus
  • whale watching
  • Azores
  • behavioral budget
  • land observations
  • resting behavior
  • bottle-nosed dolphins
  • Orcinus-orca
  • sampling methods
  • Tursiops SPP.
  • New-Zealand
  • tour boats
  • behavior
  • disturbance
  • Florida
  • model

Cite this

Visser, F., Hartman, K. L., Rood, E. J. J., Hendriks, A. J. E., Zult, D. B., Wolff, W. J., ... Pierce, G. J. (2011). Risso's dolphins alter daily resting pattern in response to whale watching at the Azores. Marine Mammal Science, 27(2), 366-381. https://doi.org/10.1111/j.1748-7692.2010.00398.x

Risso's dolphins alter daily resting pattern in response to whale watching at the Azores. / Visser, Fleur; Hartman, Karin L.; Rood, Ente J. J.; Hendriks, Arthur J. E.; Zult, Daan B.; Wolff, Wim J.; Huisman, Jef; Pierce, Graham J.

In: Marine Mammal Science, Vol. 27, No. 2, 04.2011, p. 366-381.

Research output: Contribution to journalArticle

Visser, F, Hartman, KL, Rood, EJJ, Hendriks, AJE, Zult, DB, Wolff, WJ, Huisman, J & Pierce, GJ 2011, 'Risso's dolphins alter daily resting pattern in response to whale watching at the Azores', Marine Mammal Science, vol. 27, no. 2, pp. 366-381. https://doi.org/10.1111/j.1748-7692.2010.00398.x
Visser, Fleur ; Hartman, Karin L. ; Rood, Ente J. J. ; Hendriks, Arthur J. E. ; Zult, Daan B. ; Wolff, Wim J. ; Huisman, Jef ; Pierce, Graham J. / Risso's dolphins alter daily resting pattern in response to whale watching at the Azores. In: Marine Mammal Science. 2011 ; Vol. 27, No. 2. pp. 366-381.
@article{bc95b01c81e340ccaefcdd17a69583dc,
title = "Risso's dolphins alter daily resting pattern in response to whale watching at the Azores",
abstract = "Behavioral responses of Risso's dolphins (Grampus griseus) to whale watching vessels were studied off Pico Island, Azores. Dolphin behavior was studied from a land-based lookout, enabling observations of groups in the absence and presence of vessels. The number of whale watching vessels showed a clear seasonal pattern, dividing the whale watching period into a low season and a high season. During the low season, Risso's dolphins rested mainly in the morning and afternoon. During the high season, Risso's dolphins rested less and did so mainly at noon, when the number of active vessels was lowest. Data analysis using a generalized additive mixed model indicated that this change in resting behavior was associated with vessel abundance. When more than five vessels were present, Risso's dolphins spent significantly less time resting and socializing. During the high season, this vessel abundance was exceeded during 20{\%} of observation days. While we cannot be sure that the observed changes in behavior have fitness consequences for Risso's dolphins, reduced resting and socializing rates can have negative impacts on the build-up of energy reserves and on reproductive success. We suggest the adoption of precautionary management measures to regulate the timing and intensity of whale watching activities.",
keywords = "Risso's dolphin, Grampus griseus, whale watching, Azores, behavioral budget, land observations, resting behavior, bottle-nosed dolphins, Orcinus-orca, sampling methods, Tursiops SPP., New-Zealand, tour boats, behavior, disturbance, Florida, model",
author = "Fleur Visser and Hartman, {Karin L.} and Rood, {Ente J. J.} and Hendriks, {Arthur J. E.} and Zult, {Daan B.} and Wolff, {Wim J.} and Jef Huisman and Pierce, {Graham J.}",
year = "2011",
month = "4",
doi = "10.1111/j.1748-7692.2010.00398.x",
language = "English",
volume = "27",
pages = "366--381",
journal = "Marine Mammal Science",
issn = "0824-0469",
publisher = "Wiley-Blackwell",
number = "2",

}

TY - JOUR

T1 - Risso's dolphins alter daily resting pattern in response to whale watching at the Azores

AU - Visser, Fleur

AU - Hartman, Karin L.

AU - Rood, Ente J. J.

AU - Hendriks, Arthur J. E.

AU - Zult, Daan B.

AU - Wolff, Wim J.

AU - Huisman, Jef

AU - Pierce, Graham J.

PY - 2011/4

Y1 - 2011/4

N2 - Behavioral responses of Risso's dolphins (Grampus griseus) to whale watching vessels were studied off Pico Island, Azores. Dolphin behavior was studied from a land-based lookout, enabling observations of groups in the absence and presence of vessels. The number of whale watching vessels showed a clear seasonal pattern, dividing the whale watching period into a low season and a high season. During the low season, Risso's dolphins rested mainly in the morning and afternoon. During the high season, Risso's dolphins rested less and did so mainly at noon, when the number of active vessels was lowest. Data analysis using a generalized additive mixed model indicated that this change in resting behavior was associated with vessel abundance. When more than five vessels were present, Risso's dolphins spent significantly less time resting and socializing. During the high season, this vessel abundance was exceeded during 20% of observation days. While we cannot be sure that the observed changes in behavior have fitness consequences for Risso's dolphins, reduced resting and socializing rates can have negative impacts on the build-up of energy reserves and on reproductive success. We suggest the adoption of precautionary management measures to regulate the timing and intensity of whale watching activities.

AB - Behavioral responses of Risso's dolphins (Grampus griseus) to whale watching vessels were studied off Pico Island, Azores. Dolphin behavior was studied from a land-based lookout, enabling observations of groups in the absence and presence of vessels. The number of whale watching vessels showed a clear seasonal pattern, dividing the whale watching period into a low season and a high season. During the low season, Risso's dolphins rested mainly in the morning and afternoon. During the high season, Risso's dolphins rested less and did so mainly at noon, when the number of active vessels was lowest. Data analysis using a generalized additive mixed model indicated that this change in resting behavior was associated with vessel abundance. When more than five vessels were present, Risso's dolphins spent significantly less time resting and socializing. During the high season, this vessel abundance was exceeded during 20% of observation days. While we cannot be sure that the observed changes in behavior have fitness consequences for Risso's dolphins, reduced resting and socializing rates can have negative impacts on the build-up of energy reserves and on reproductive success. We suggest the adoption of precautionary management measures to regulate the timing and intensity of whale watching activities.

KW - Risso's dolphin

KW - Grampus griseus

KW - whale watching

KW - Azores

KW - behavioral budget

KW - land observations

KW - resting behavior

KW - bottle-nosed dolphins

KW - Orcinus-orca

KW - sampling methods

KW - Tursiops SPP.

KW - New-Zealand

KW - tour boats

KW - behavior

KW - disturbance

KW - Florida

KW - model

U2 - 10.1111/j.1748-7692.2010.00398.x

DO - 10.1111/j.1748-7692.2010.00398.x

M3 - Article

VL - 27

SP - 366

EP - 381

JO - Marine Mammal Science

JF - Marine Mammal Science

SN - 0824-0469

IS - 2

ER -