Increasing trends in fecundity and calf survival of bottlenose dolphins in a marine protected area

Barbara J. Cheney; Paul M. Thompson; Line S. Cordes

doi:10.1038/s41598-018-38278-9

Increasing trends in fecundity and calf survival of bottlenose dolphins in a marine protected area

Barbara J. Cheney^* (Corresponding Author), Paul M. Thompson, Line S. Cordes

^*Corresponding author for this work

Bangor University

Research output: Contribution to journal › Article › peer-review

14 Citations (Scopus)

12 Downloads (Pure)

Abstract

Estimates of temporal variation in demographic rates are critical for identifying drivers of population change and supporting conservation. However, for inconspicuous wide-ranging species, births may be missed and fecundity rates underestimated. We address this issue using photo-identification data and a novel robust design multistate model to investigate changes in bottlenose dolphin fecundity and calf survival. The model allows for uncertainty in breeding status, and seasonal effects. The best model estimated an increase in the proportion of females with newborn calves from 0.16 (95% CI = 0.11–0.24) in 2001 to 0.28 (95% CI = 0.22–0.36) in 2016. First year calf survival also increased over this period from 0.78 (95% CI = 0.53–0.92) to 0.93 (95% CI = 0.82–0.98). Second year calf survival remained lower, but also showed an increase from 0.32 (95% CI = 0.19–0.48) to 0.55 (95% CI = 0.44–0.65). Females with newborn calves had a slightly higher mortality than those with older calves, but further work is required to evaluate potential costs of reproduction. This study presents a rare example of empirical evidence of a positive trend in reproduction and survival for a cetacean population using a Marine Protected Area.

Original language	English
Article number	1767
Number of pages	9
Journal	Scientific Reports
Volume	9
DOIs	https://doi.org/10.1038/s41598-018-38278-9
Publication status	Published - 11 Feb 2019

Bibliographical note

We are indebted to Bill Kendall who provided critical input to the development of these analyses while LSC was visiting Colorado State University. Scottish Natural Heritage, Whale and Dolphin Conservation, Talisman Energy (UK) Ltd., Department of Energy and Climate Change, Chevron, Beatrice Offshore Windfarm Ltd., Moray Offshore Renewables Ltd., Marine Scotland, The Crown Estate and Highlands and Islands Enterprise all provided funding for photo-identification surveys. Many thanks to all the colleagues who have helped collect data for this long-term study. Survey work was conducted under Scottish Natural Heritage Animal Scientific Licences.

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1038/s41598-018-38278-9Licence: CC BY

Increasing trends in fecundity and calf survival of bottlenose dolphins in a marine protected area
© The Author(s) 2019. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
Final published version, 1.53 MBLicence: CC BY

Cite this

@article{29cb1e483be4482f972b1abc7303f4ae,

title = "Increasing trends in fecundity and calf survival of bottlenose dolphins in a marine protected area",

abstract = "Estimates of temporal variation in demographic rates are critical for identifying drivers of population change and supporting conservation. However, for inconspicuous wide-ranging species, births may be missed and fecundity rates underestimated. We address this issue using photo-identification data and a novel robust design multistate model to investigate changes in bottlenose dolphin fecundity and calf survival. The model allows for uncertainty in breeding status, and seasonal effects. The best model estimated an increase in the proportion of females with newborn calves from 0.16 (95% CI = 0.11–0.24) in 2001 to 0.28 (95% CI = 0.22–0.36) in 2016. First year calf survival also increased over this period from 0.78 (95% CI = 0.53–0.92) to 0.93 (95% CI = 0.82–0.98). Second year calf survival remained lower, but also showed an increase from 0.32 (95% CI = 0.19–0.48) to 0.55 (95% CI = 0.44–0.65). Females with newborn calves had a slightly higher mortality than those with older calves, but further work is required to evaluate potential costs of reproduction. This study presents a rare example of empirical evidence of a positive trend in reproduction and survival for a cetacean population using a Marine Protected Area.",

author = "Cheney, {Barbara J.} and Thompson, {Paul M.} and Cordes, {Line S.}",

note = "We are indebted to Bill Kendall who provided critical input to the development of these analyses while LSC was visiting Colorado State University. Scottish Natural Heritage, Whale and Dolphin Conservation, Talisman Energy (UK) Ltd., Department of Energy and Climate Change, Chevron, Beatrice Offshore Windfarm Ltd., Moray Offshore Renewables Ltd., Marine Scotland, The Crown Estate and Highlands and Islands Enterprise all provided funding for photo-identification surveys. Many thanks to all the colleagues who have helped collect data for this long-term study. Survey work was conducted under Scottish Natural Heritage Animal Scientific Licences.",

year = "2019",

month = feb,

day = "11",

doi = "10.1038/s41598-018-38278-9",

language = "English",

volume = "9",

journal = "Scientific Reports",

issn = "2045-2322",

publisher = "Nature Publishing Group",

}

TY - JOUR

T1 - Increasing trends in fecundity and calf survival of bottlenose dolphins in a marine protected area

AU - Cheney, Barbara J.

AU - Thompson, Paul M.

AU - Cordes, Line S.

N1 - We are indebted to Bill Kendall who provided critical input to the development of these analyses while LSC was visiting Colorado State University. Scottish Natural Heritage, Whale and Dolphin Conservation, Talisman Energy (UK) Ltd., Department of Energy and Climate Change, Chevron, Beatrice Offshore Windfarm Ltd., Moray Offshore Renewables Ltd., Marine Scotland, The Crown Estate and Highlands and Islands Enterprise all provided funding for photo-identification surveys. Many thanks to all the colleagues who have helped collect data for this long-term study. Survey work was conducted under Scottish Natural Heritage Animal Scientific Licences.

PY - 2019/2/11

Y1 - 2019/2/11

N2 - Estimates of temporal variation in demographic rates are critical for identifying drivers of population change and supporting conservation. However, for inconspicuous wide-ranging species, births may be missed and fecundity rates underestimated. We address this issue using photo-identification data and a novel robust design multistate model to investigate changes in bottlenose dolphin fecundity and calf survival. The model allows for uncertainty in breeding status, and seasonal effects. The best model estimated an increase in the proportion of females with newborn calves from 0.16 (95% CI = 0.11–0.24) in 2001 to 0.28 (95% CI = 0.22–0.36) in 2016. First year calf survival also increased over this period from 0.78 (95% CI = 0.53–0.92) to 0.93 (95% CI = 0.82–0.98). Second year calf survival remained lower, but also showed an increase from 0.32 (95% CI = 0.19–0.48) to 0.55 (95% CI = 0.44–0.65). Females with newborn calves had a slightly higher mortality than those with older calves, but further work is required to evaluate potential costs of reproduction. This study presents a rare example of empirical evidence of a positive trend in reproduction and survival for a cetacean population using a Marine Protected Area.

AB - Estimates of temporal variation in demographic rates are critical for identifying drivers of population change and supporting conservation. However, for inconspicuous wide-ranging species, births may be missed and fecundity rates underestimated. We address this issue using photo-identification data and a novel robust design multistate model to investigate changes in bottlenose dolphin fecundity and calf survival. The model allows for uncertainty in breeding status, and seasonal effects. The best model estimated an increase in the proportion of females with newborn calves from 0.16 (95% CI = 0.11–0.24) in 2001 to 0.28 (95% CI = 0.22–0.36) in 2016. First year calf survival also increased over this period from 0.78 (95% CI = 0.53–0.92) to 0.93 (95% CI = 0.82–0.98). Second year calf survival remained lower, but also showed an increase from 0.32 (95% CI = 0.19–0.48) to 0.55 (95% CI = 0.44–0.65). Females with newborn calves had a slightly higher mortality than those with older calves, but further work is required to evaluate potential costs of reproduction. This study presents a rare example of empirical evidence of a positive trend in reproduction and survival for a cetacean population using a Marine Protected Area.

UR - http://www.scopus.com/inward/record.url?scp=85061293294&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/increasing-trends-fecundity-calf-survival-bottlenose-dolphins-marine-protected-area

U2 - 10.1038/s41598-018-38278-9

DO - 10.1038/s41598-018-38278-9

M3 - Article

SN - 2045-2322

VL - 9

JO - Scientific Reports

JF - Scientific Reports

M1 - 1767

ER -

Increasing trends in fecundity and calf survival of bottlenose dolphins in a marine protected area

Abstract

Bibliographical note

UN SDGs

Access to Document

Other files and links

Fingerprint