We studied the nesting ecology of Black Skimmers along the lower Texas coast during 1978-1981 to learn more of their reproductive status and to evaluate the effects of organochlorine pollutants, such as DDE, on productivity. For 542 nests, the average clutch size was 3.3 eggs. Flooding was the major cause of colony destruction and abandonment. Clutch size in renest attempts decreased significantly from that in first attempts. Overall fledging success (fledglings/total pairs) averaged 1 0 fledgling per pair. There was a significant negative correlation between number of nest attempts and fledging success on a colony basis. Also, clutch size and fledging success were significantly correlated. DDE residues in some skimmer eggs were high (up to 51 ppm, wet weight), with 35% of all eggs sampled containing- >1 0 ppm DDE. However, eggshell thinning of only 4-12% was demonstrated on a colony basis and log DDE residues in individual eggs were not significantly correlated with shell thickness. DDE residues in Texas eggs were 5-fold higher than in South Carolina eggs where no shell thinning was detected.
Additional publication details
Reproductive success of black skimmers in Texas relative to environmental pollutants