Persons involved: Jeffrey Sonnentag, Martin Wikelski, Mónica Freire Pesántez, Franz Kümmeth, Daniel G. Vergara Granda

Dates - Arrival:    May 7, 1997
         Departed:    June 23, 1997

Activities involved in/purpose for trip: Hatchling marine iguanas were captured, measured, permanently marked, and a blood sample was taken in order to continue research on value of female selection of a male to copulate with during mating season.

Marine iguanas: Many of the marine iguanas were very skinny with their pelvic bones protruding.  Some of those worst off died while we were there (approximately 6-10).  Those that died were female size (both marked and unmarked).  488 hatchlings were captured and marked.  Hatchlings (both marked and unmarked) were seen being preyed upon by Lava Gulls, Striated Herons, a Great Blue Heron (seen at 1 time eating 3 hatchlings in 1 day - 1 marked 2 unmarked), and even red crabs attempted capture.  Some iguanas were seen coming inside the island regularly to eat a land plant (a succulent with yellow flowers and round leaves - NOT the one with narrow leaves and pink flowers).  They were also observed to continue their relatively frequent feeding on bird feces and available dead organisms that periodically washed up on the beach.  Positions of rest while not feeding appeared to return to where they had been prior to the nesting period (during the breeding season).  Following the mating period, after which the majority of males left the island, there were shifts in resting location [for whatever reason(s)].

Land iguanas: Both land iguanas were spotted.

Geckos: There were an increased number of geckos around and under rocks inside the island (compared to earlier in the year).

Sea lions: It appeared there were a few less than there were in March.  During the entire stay 5 aborted sea lions were seen and 3 dead sea lions of medium size were washed up on the beach.  They continued to poop, crawl over everything, make noise at all hours of the day/night, and in general make nuisances of themselves.  But they were in general friendly (laying around our table and under our feet). . . .

Frigate birds: The birds made fewer visits to the lighthouse this time (compared to January-March).  They usually stayed around the island (scanning the beaches) for short periods of time.

Blue-footed boobies: There were about the same number as before (maybe 30) that sat around at various times of the day - usually at night.

Brown pelicans: Approximately the same number as before - about 5 coming and going throughout the day.

Ruddy turnstones(?): The small birds that waded around the pools in the middle of the island had plenty of soft ground to dig in so they stayed around almost the entire time.

Yellow warblers and finches: There were lots of these birds eating flies and other bugs.  There were not many new nests though.

Insects and other bugs: There were a great number of grasshoppers, spiders, and various other small insects due to the wet conditions and abundance of plant life.

Plants: All the plants were very green, although their period of rapid growth seemed to have been passed.  They appeared to grow faster right after it rained at the end of February and March, but that might just be because little change then would make a big difference in appearance.  3 or 4 types of mushrooms were seen growing on the island.  Most plants appeared to have finished flowering (that done in February and March) and were just green.

Intertidal life: There was little algae to begin with and then it went up as the higher tides came and water covered the rocks more of each day.  The long brown algae on the rocks farthest out was gone when we arrived but had started growing back by the time we left.  There appeared to be plenty of the red algae the iguanas eat around the barnacles but the tides were not usually low enough that they had much time to go eat it.  A few morenas were observed in the intertidal and 1 octopus.

Weather: It was wet the entire time we were on the island.  Following the hardest rain (all night) the low portions of the island in the middle were completely flooded.  1/3 of the island was covered with water.  However after 1 week the level was back down to what it was when we arrived (which was still much higher than it ever got in January-March).

Water: The temperature of the water stayed between 26-27 C the entire time.
 

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