Jalova Subzone: The daily surveys 4/1-6/15) recorded 376 

 nests (Fig. 1). The peak of nesting was 5/2-6/1. The most fresh 

 nests recorded on a single day was 12 (5/2, 5/9, 5/11). False 

 crawls were 20.0% of the total fresh tracks (Subzone 4B) . 



NEST LIFE AND TRACK LIFE 



It has been obvious that sea turtle tracks and body-pits are 

 erased, after some variable time period, by the forceful effects 

 of tide, wind, and rain (and sometimes man and other factors) . 



In the Matina and Jalova subzones we had a cumulative daily 

 record of the number of nests that had been laid, and we 

 maintained daily records of residual tracks and body-pits that 

 were visible. The following sample indicates the percent of 

 nests (body-pits) and tracks that are obliterated during a 

 season: 



AERIAL SURVEYS 



Nesting occurs all along the coast. We flew north of Rio 

 Colorado only once in 1987 because of safety precautions. On 

 three of the four flights we surveyed into Panama to Boca del 

 Drago and recorded dozens of leatherback tracks there. On one 

 flight (4/17) we were able to survey Playa Chiriqui, Panama, and 

 recorded 235 leatherback body-pits between Rio Canaveral and Rio 

 Chiriqui. 



In Costa Rica, about 8 to 15% of the total leatherback 

 nesting occurs to the south of Puerto Limon. 



From prior years we had determined that the number of 

 leatherback body-pits counted from the air was less than those 

 more reliably recorded from beach surveys. The error increased 

 both as the season progressed and from north to south in the 

 Tortuguero to Moin area (the latter for reasons remaining to be 

 verified) . I estimated correction factors by zone and subzone 

 from the ground truth surveys and multiplied these to give 

 estimates of number of nests along the entire coast at mid-month 

 periods. 



306 



