Blacked-legged Kittiwakes are pelagic gulls that often feed on fish and macro-zooplankton at the ocean surface. They breed in colonies ranging from few to thousands of pairs which prominently observed in their open, sea-cliff nesting habitats. Blacked-legged Kittiwakes are the most popular models for research because they can be easily monitored and captured. They also considered as prime indicators of fluctuating conditions in marine ecosystem. The purpose of this research is to collect live sperm of blacked-legged Kittiwakes using a non-invasive method. Also, be able to provide information on suitable extenders and timing in relations to the breeding phenology. Additionally, it will offer informations to different disciplines including veterinary science, conservation biology, ecotoxicology and evolutionary biology.
Sperm collection of Blacked-legged Kittiwakes
Sperm of blacked-legged Kittiwakes were obtained by firmly massaging the lower back and the tail base of the male bird. Since, the researchers observed that during mating the male tend to wag their tails thus, releasing the sperm naturally. After massaging the handler lift the tail, clear the feathers around cloaca and gently squeeze the cloacal area. While doing this a capillary tube placed on the top of the cloaca to collect directly the translucent liquid. Then, verified directly to the laboratory under the microscope.
The result demonstrates a successful collection of live sperm under field condition of blacked-legged Kittiwakes for the first time. In which the researchers discovered two extenders suitable for maintaining the sperm however, undiluted sperm also performed well in terms of survival. Since, seminal fluids alone are sufficient enough to maintain the sperm alive. Though, the researchers still recommend using sperm extenders since it is necessary to dilute highly concentrated ejaculates. Also, extenders are necessary on sperm quality examination when comparing experimental groups and sperm production.
Blacked-legged Kittiwakes are strictly monogamous and stores semen inside their body unlike passerine birds that stores semen in seminal glomera. Interestingly, one has to keep in mind that sperm quality may vary seasonally. So, the researchers suggest that one should statistically account for this effects using date relative to laying eggs. Also the researchers recommends to target specific time window when the birds are about to copulate but not after copulation within a day.
Source: Prepared by Joan Tura from BMC Avian Research
Volume 9:24, 14 July 2018