[MARMAM] New publication: reproductive parameters for common dolphins
susan.chivers at noaa.gov
Tue Jun 30 14:37:39 PDT 2015
We are pleased to announce publication of the following article:
Chivers, S. J., W. L. Perryman, M. S. Lynn, T. Gerrodette, F. I. Archer,
K. Danil, M. Berman-Kowalewski, and J. P. Dines. 2015. Comparison of
reproductive parameters for populations of eastern North Pacific common
dolphins: /Delphinus capensis/ and /D. delphis/. Marine Mammal Science
Reproductive parameters were estimated and compared for eastern North
Pacific populations of common dolphins using specimen and
photogrammetric data. Age and length data for /Delphinus capensis/ and
/D. delphis/ specimens recovered as bycatch or strandings were used to
estimate the postnatal growth rates needed to estimate age for calves
measured in aerial photographs. Bayesian methods propagated uncertainty
among models and revealed that the 2009 cohort of calves had birth dates
centered on 6 March 2009 for /D. capensis/ and 12 December 2008 for /D.
delphis/. The evidence for discrete calving seasons suggests a mechanism
of reproductive isolation has evolved between species. Photogrammetric
data and Bayesian methods were also used to estimate the average length
at which calves swim independently: 145.1 cm (≈ 11.1 mo) in /D.
capensis/ and 140.1 cm (≈ 14.0 mo) in /D. delphis/, and the proportion
of calves (calves/dolphins counted): 0.045 in /D. capensis/ and 0.069 in
/D. delphis/. The latter parameter was converted to an index of calf
production (calf/female dolphin) that was >50% lower than pregnancy
rates suggesting few births occurred during the study year. Comparisons
of regional differences in calf production suggest variability in
habitat use patterns within the study area.
You may also contact me at susan.chivers at noaa.gov
<mailto:susan.chivers at noaa.gov> for a pdf.
Susan J. Chivers, Ph.D.
Marine Mammal and Turtle Division
Southwest Fisheries Science Center
National Marine Fisheries Service
National Oceanic and Atmospheric Administration
8901 La Jolla Shores Dr.
La Jolla, CA 92037 USA
Email: Susan.Chivers at noaa.gov
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the MARMAM