A method for collecting and evaluating semen from Rockhopper penguins (Eudyptes chrysocome chrysocome) was developed to evaluate the low egg fertility rate found in our population. At the current rate of fertility and hatchability, we do not have a self-sustaining population.
Six adult male Rockhopper penguins were used in this study. All six animals were conditioned to allow handling prior to the breeding season. Samples were collected once a week starting at the earliest projected date for the start of breeding season. After an individual animal had 2 weeks of no ejaculate or ejaculate with no spermatozoa present, they were no longer collected. A total of 59 samples were collected between 17 September and 31 December 2004. Forty-five of these samples were evaluated for volume and pH of ejaculate, spermatozoa concentration, and sperm quality (motility, viability and morphology). There was a large variation between individuals and between weeks for each individual. The average motility was 34.5%. Average volume of ejaculate was 0.23 ml. Average concentration of spermatozoa per ml was 16x106. Average number of spermatozoa per collection was 1.7x106. Average fraction of living spermatozoa was 82.9%. Average fraction of spermatozoa with normal morphology was 82.1%. Average pH was 6.47. During this season, only one of these males paired up with a female. They produced one fertile egg; unfortunately, the embryo died early in incubation.
Comparing these results with values found in Magellanic penguins (Spheniscus magellanicus), where sperm concentration was 243.4x106/ml and total sperm per ejaculate was 6.4x106,1 the males in our study population may be playing a large role in our decreased fertility. Additional studies will be done in the next breeding season to look at all of the males in the population and perform artificial insemination on unpaired females who are laying eggs.
1. O’Brien, J.K., D.A. Oehler, S.P. Malowski, and T.L. Roth. 1999. Semen collection, characterization, and cryopreservation in a Magellanic penguin (Spheniscus magellanicus). Zoo Biol. 18:199–214.