Goodbye Elephant Seals, Hello Seabirds!
By Point Blue at Los Farallones | March 24, 2015
March 11thmarked the end of the 2014-2015 SEFI elephant seal breeding season. Pup -91 was the last to wean. This year we had 93 cows, 67 of which pupped. Of those 67, 42 successfully weaned. When going through our data, we noticed that there was higher pup mortality this winter season. One reason for this could be that more cows pupped in Mirounga Beach, a narrow inlet that doesn’t allow for much movement during tidal surges and storms. This resulted in multiple pups being crushed or washed out to sea.
|Cows and pups in Mirounga Beach|
Another bit of information to take into consideration is that Andre, the bull in the area, moved between Sand Flat and Mirounga Beach rather frequently this season, which may have led to an increased movement of males and thus a greater chance of crushing pups.
|Andre at the entrance to Mirounga Beach|
This winter season was quite warm compared to previous years. During warm days, cows, pups, and weaners would often congregate in the water puddles near Breaker Cove, an inlet just below Breaker Terrace and Sand Flat. As many pups and weaners moved close to the edge to seek out cooler temperatures, they fell into the cove. Since the weaners are unable to swim at this point, those that fell in were washed out to sea.
|A weaner splashing around in the water puddles near Breaker Cove|
As for the other pinnipeds on the island, the number of California sea lions has increased dramatically in the past couple of weeks. It is becoming harder to access certain areas on the island without disrupting them, so we have been very cautious not to disturb them.
This past Saturday, March 14th, was the end of the 2014-2015 SEFI winter season. During our last week, we decided to make corn hole boards to leave on the island for the future interns and biologists. After many hours in the ‘carp shop’ and sewing bean bags from old pillow cases, they were finally complete. We decorated them with a spray painted elephant seal and common murre. We finished them just in time to get a few games in for ourselves.
It was hard to say goodbye, but we will forever have such wonderful memories of this past winter on SEFI.
As hard as it is to say goodbye to the elephant seals and the winter crew, we welcome the seabird season and its crew whole-heartedly. Most of the work we have done so far is maintenance and gearing up for the busy season ahead. We have been cleaning out and repairing the 447 Cassin’s Auklet boxes scattered throughout the island. We found our first Cassin’s in one of the PRBO boxes near North Landing last week, though it was without an egg.
Things should pick up as the seabird season gets underway, so check back soon for further updates!
– Written by 2015 Point Blue winter research assistant Vanessa Delnavaz