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Demography of the endangered North Atlantic right whale

Nature volume 414, pages 537–541 (2001)Cite this article

Abstract

Northern right whales (Eubalaena glacialis) were formerly abundant in the northwestern Atlantic, but by 1900 they had been hunted to near extinction. After the end of commercial whaling the population was thought to be recovering slowly; however, evidence indicates that it has been declining since about 1990 (ref. 1). There are now fewer than 300 individuals, and the species may already be functionally extinct2,3 owing to demographic stochasticity or the difficulty of females locating mates in the vast Atlantic Ocean (Allee effect4). Using a data set containing over 10,000 sightings of photographically identified individuals we estimated trends in right whale demographic parameters since 1980. Here we construct, using these estimates, matrix population models allowing us to analyse the causes of right whale imperilment. Mortality has increased, especially among mother whales, causing declines in population growth rate, life expectancy and the mean lifetime number of reproductive events between the period 1980–1995. Increased mortality of mother whales can explain the declining population size, suggesting that the population is not doomed to extinction as a result of the Allee effect. An analysis of extinction time shows that demographic stochasticity has only a small effect, but preventing the deaths of only two female right whales per year would increase the population growth rate to replacement level.

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Figure 1: Life cycle graphs of female (a) and male (b) right whales.
Figure 2: Stage-specific sighting and survival probabilities for males and females.
Figure 3: Constant transition probabilities estimated using the best sighting model (M1).
Figure 4
Figure 5: Demographic parameters calculated from the time-varying matrices At.
Figure 6: The probability distribution of time to extinction assuming demographic stochasticity.
Figure 7

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References

  1. Caswell, H., Fujiwara, M. & Brault, S. Declining survival probability threatens the North Atlantic right whale. Proc. Natl Acad. Sci. USA 96, 3308–3313 (1999).

    Article  ADS  CAS  Google Scholar 

  2. Knowlton, A. R., Kraus, S. D. & Kenney, R. D. Reproduction in North Atlantic right whales (Eubalaena glacialis). Can. J. Zool. 72, 1297–1305 (1994).

    Article  Google Scholar 

  3. Gerber, L. R., DeMaster, D. P. & Roberts, S. P. Measuring success in conservation. Am. Sci. 88, 316–324 (2000).

    Article  ADS  Google Scholar 

  4. Allee, W. C. Animal Aggregations (Univ. Chicago Press, Chicago, 1931).

    Google Scholar 

  5. Caswell, H. Matrix Population Models: Construction, Analysis and Interpretation 2nd edn (Sinauer Associates, Sunderland, Massachusetts, 2001).

    Google Scholar 

  6. Caswell, H. Matrix Population Models (Sinauer Associates, Sunderland, Massachusetts, 1989).

    Google Scholar 

  7. Tuljapurkar, S. & Caswell, H. Structured-population Models in Marine, Terrestrial, and Freshwater Systems (Chapman & Hall, New York, 1997).

    Book  Google Scholar 

  8. Brault, S. & Caswell, H. Pod-specific demography of killer whales (Orcinus orca). Ecology 74, 1444–1454 (1993).

    Article  Google Scholar 

  9. Nichols, J. D., Sauer, J. R., Pollock, K. H. & Hestbeck, J. B. Estimating transition probabilities for stage-based population projection matrices using capture-recapture data. Ecology 73, 306–312 (1992).

    Article  Google Scholar 

  10. Fujiwara, M. & Caswell, H. Estimating population projection matrices from multi-stage mark-recapture data. Ecology (in the press).

  11. Crone, M. J. & Kraus, S. D. Right Whale (Eubalaena glacialis) in the Western North Atlantic: a Catalog of Identified Individuals (New England Aquarium, Boston, Massachusetts, 1990).

    Google Scholar 

  12. Akaike, H. in International Symposium on Information Theory 2nd edn (eds Petran, B. N. & Csaki, F.) 267–281 (Akademiai Kiado, Budapest, 1973).

    Google Scholar 

  13. Lebreton, J.-D., Burnham, K. P., Clobert, J. & Anderson, D. R. Modeling survival and testing biological hypotheses using marked animals: a unified approach with case studies. Ecol. Monogr. 62, 67–118 (1992).

    Article  Google Scholar 

  14. Burnham, K. P. & Anderson, D. R. Model Selection and Inference: a Practical Information-theoretic Approach (Springer, New York, 1998).

    Book  Google Scholar 

  15. Olesiuk, P. F., Bigg, M. A. & Ellis, G. M. in Individual Recognition of Cetaceans: Use of Photo-identification and Other Techniques to Estimate Population Parameters (eds Hammond, P. S., Mizroch, S. A. & Donovan, G. P.) 209–243 (Rep. Int. Whaling Comm. Special Issue 12, Cambridge, 1990).

    Google Scholar 

  16. Kraus, S. D. Rates and potential causes of mortality in North Atlantic right whales (Eubalaena glacialis). Mar. Mamm. Sci. 6, 278–291 (1990).

    Article  ADS  Google Scholar 

  17. Waring, G. T. et al. U.S. Atlantic and Gulf of Mexico Marine Mammal Stock Assessments—1999. NOAA Technical Memorandum NMFS-NE-153 (Northeast Fisheries Science Center, Woods Hole, Massachusetts, 1999).

    Google Scholar 

  18. Kraus, S . D., Prescott, J. H., Knowlton, A. R. & Stone, G. S. in Right Whale: Past and Present Status (eds Brownell, R. L. Jr, Best, P. B. & Prescott, J. H.) 145–151 (Rep. Int. Whaling Comm. Special Issue 10, Cambridge, 1986).

    Google Scholar 

  19. Knowlton, A. R. in Shipping/Right Whale Workshop (eds Knowlton, A. R., Kraus, S. D., Meck, D. F. & Mooney-Seus, M. L.) 31–36 (New England Aquarium Aquatic Forum Series Report 97–3, Massachusetts, 1997).

    Google Scholar 

  20. Planque, B. & Reid, P. C. Predicting Calanus finmarchicus abundance from a climatic signal. J. Mar. Biol. Ass. UK 78, 1015–1018 (1998).

    Article  Google Scholar 

  21. Holden, C. Whale baby boomlet. Science 291, 429 (2001).

    CAS  Google Scholar 

  22. Hosmer, D. W. & Lemeshow, D. Applied Logistic Regression (Wiley, New York, 1989).

    MATH  Google Scholar 

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Acknowledgements

We thank S. Kraus, A. Knowlton, P. Hamilton and the NEA for data. We also thank S. Brault, M. Hill, P. Kareiva, J.-D. Lebreton, M. Neubert, J. Nichols and the participants of the first Woods Hole Workshop on the Demography of Marine Mammals for discussions and suggestions. This project was funded by the Woods Hole Oceanographic Institution Sea Grant Program, the Rinehart Coastal Research Center, the David and Lucile Packard Foundation and The Robert W. Morse Chair.

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  1. Biology Department, MS34, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA

    Masami Fujiwara & Hal Caswell

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  1. Masami Fujiwara
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  2. Hal Caswell
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Correspondence to Masami Fujiwara.

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Fujiwara, M., Caswell, H. Demography of the endangered North Atlantic right whale. Nature 414, 537–541 (2001). https://doi.org/10.1038/35107054

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