Updated application of a photo-identification based assessment model to southern right whales in South African waters, focussing on inferences to be drawn from a series of appreciably lower counts of calving females over 2015 to 2017
| dc.contributor.author | Brandão, Anabela | |
| dc.contributor.author | Vermeulen, Els | |
| dc.contributor.author | Ross-Gillespie, Andrea | |
| dc.contributor.author | Findlay, Ken | |
| dc.contributor.author | Butterworth, Doug S | |
| dc.date.accessioned | 2019-12-18T08:45:49Z | |
| dc.date.available | 2019-12-18T08:45:49Z | |
| dc.date.issued | 2018 | |
| dc.description.abstract | This paper extends the analyses of Brandão et al. (2013) which applied the three-mature-stages (receptive, calving and resting) model of Cooke et al. (2003) to photo-identification data available from 1979 to 2012 for southern right whales in South African waters, by taking five further years of data into account. The lower counts of calving females over 2015 to 2017 are indicated to be a reflection of time variability in the probability that a resting whale rests another year, rather than of any mass mortality. The 2017 number of parous females is estimated to be 1 765, the total population (including males and calves) 6 116, and the annual population growth rate 6.5%. This reflects a small decrease to the 6.6% increase rate estimated previously; even in the instance of lesser numbers seen in recent years than estimated previously. Information from resightings of grey blazed calves as adults with calves allows estimation of first year survival rate of 0.852, a slight increase from the previous estimate of 0.850, compared to a subsequent annual rate of 0.988. | en_US |
| dc.identifier.apacitation | Brandão, A., Vermeulen, E., Ross-Gillespie, A., Findlay, K., & Butterworth, D. (2018). <i>Updated application of a photo-identification based assessment model to southern right whales in South African waters, focussing on inferences to be drawn from a series of appreciably lower counts of calving females over 2015 to 2017</i> ,Faculty of Science ,Department of Mathematics and Applied Mathematics. Retrieved from http://hdl.handle.net/11427/30708 | en_ZA |
| dc.identifier.chicagocitation | Brandão, Anabela, Els Vermeulen, Andrea Ross-Gillespie, Ken Findlay, and Doug Butterworth <i>Updated application of a photo-identification based assessment model to southern right whales in South African waters, focussing on inferences to be drawn from a series of appreciably lower counts of calving females over 2015 to 2017.</i> ,Faculty of Science ,Department of Mathematics and Applied Mathematics, 2018. http://hdl.handle.net/11427/30708 | en_ZA |
| dc.identifier.citation | Brandão, A., Vermeulen, E., Ross-Gillespie, A., Findlay, K., Butterworth, D. 2018. Updated application of a photo-identification based assessment model to southern right whales in South African waters, focussing on inferences to be drawn from a series of appreciably lower counts of calving females over 2015 to 2017. | en_ZA |
| dc.identifier.ris | TY - Report AU - Brandão, Anabela AU - Vermeulen, Els AU - Ross-Gillespie, Andrea AU - Findlay, Ken AU - Butterworth, Doug AB - This paper extends the analyses of Brandão et al. (2013) which applied the three-mature-stages (receptive, calving and resting) model of Cooke et al. (2003) to photo-identification data available from 1979 to 2012 for southern right whales in South African waters, by taking five further years of data into account. The lower counts of calving females over 2015 to 2017 are indicated to be a reflection of time variability in the probability that a resting whale rests another year, rather than of any mass mortality. The 2017 number of parous females is estimated to be 1 765, the total population (including males and calves) 6 116, and the annual population growth rate 6.5%. This reflects a small decrease to the 6.6% increase rate estimated previously; even in the instance of lesser numbers seen in recent years than estimated previously. Information from resightings of grey blazed calves as adults with calves allows estimation of first year survival rate of 0.852, a slight increase from the previous estimate of 0.850, compared to a subsequent annual rate of 0.988. DA - 2018 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PY - 2018 T1 - Updated application of a photo-identification based assessment model to southern right whales in South African waters, focussing on inferences to be drawn from a series of appreciably lower counts of calving females over 2015 to 2017 TI - Updated application of a photo-identification based assessment model to southern right whales in South African waters, focussing on inferences to be drawn from a series of appreciably lower counts of calving females over 2015 to 2017 UR - http://hdl.handle.net/11427/30708 ER - | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11427/30708 | |
| dc.identifier.vancouvercitation | Brandão A, Vermeulen E, Ross-Gillespie A, Findlay K, Butterworth D. Updated application of a photo-identification based assessment model to southern right whales in South African waters, focussing on inferences to be drawn from a series of appreciably lower counts of calving females over 2015 to 2017. 2018 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/30708 | en_ZA |
| dc.language.iso | eng | |
| dc.publisher.department | Department of Mathematics and Applied Mathematics | en_US |
| dc.publisher.faculty | Faculty of Science | en_US |
| dc.title | Updated application of a photo-identification based assessment model to southern right whales in South African waters, focussing on inferences to be drawn from a series of appreciably lower counts of calving females over 2015 to 2017 | en_US |
| dc.type | Report | en_US |