.--The Ruddy Turnstone (Arenaria interpres) occasionally eats eggs of other birds. Parkes et al. (Wilson Bull. 83:306- 308, 1971) summarized 3 reports of such behavior by the Old World subspecies (.4. i. interpres) and presented 2 instances involving the New World subspecies (A. i. morinella). We report here a seemingly extreme instance of this behavior. 134 THE WILSON BULLETIN ß Vol. 91, No. I, March 1979 In May and June of ]977, wc obscrvcd the large scalc destruction by turnstones of eggs laid in a largc colony nf Royal Terns (Stera maxima) at Bird Island anti Littlc Bird Island in Nassau Sound, Duval Co., Florida, and the subsequent abandonment of the colony by lhe terns. The tcrns had nested succcssfully here in most years sincc the lalc 1950's (Sam Grimes, pcrs. conm.). This was the fourIll year of our studies in Ibis colony and the first tithe we observed the turnstone behavior. On 15 May, Sutton found Royal Terns making a strong start toward lhe eslablishuent of their anuual coltiny. The first subcolony (At had 282 eggs and was well lended. Adults were typically eahn, allowing close apprnach beforc flushing. Returning birds landed and calmed down quickly. Indications were that the colony was tiff to a good start anti wouht continue to build up to about 2000 nests as it did in 1976. On 20 May, wc found subcolony A abandoned; 20% of the eggs were broken and many of the retnaindcr were partially buricd or rolled together in groups. Two new subcolonies (B anti C) had been started about 100 m west, each contained about 150 cggs. It was apparcnt from tlc actions of the birds lhat they were under siress. Thcy flushed when nbservers were far from the colony and did not remain in groups directly nver the colony as is nnrmal. Both subcolonies contained sonic brokcn and some partly buried eggs, indicating abandonmcnt or improper care by adults. The birds did not return while we were in a blind aboul 20 m away. This was unusual. When we rctired to a greater dislance, they returned with much hesitation, flushing rcpcaledly before settling down. On 22 May, thc situatinn was as follows: subcolony l:l still contained about 40 eggs intact, but nany otbers were freshly broken; subcolony C was gone and brnken egg shclls litlercd the area; and a new subcolony (D) containing 50 eggs had been started on Little Bird Island, 0.5 km to tile west. We decided to make furthcr observations with binoculars from a distance of about 200 m. Aftcr the royals had returned and settled down on subcolony B, we saw a small group of Ruddy Turnstones enter the colony and begin pecking at eggs. To confirm that these birds were actually breaking thc eggs, we cleared the area of all shell fragments leaving 36 perfect eggs. After we retired and the royals had returned and seltled down, 6 Ruddy Turnslones and 2 Sanderlings f Calldris alba) entered the colony and began to peck at the eggs, breaking them opcn and feeding on them. Afler about 30 rain we again entcred the colony and found 6 broken eggs. We did not see Sanderlings actually breaking eggs, they may wcll have been simply feeding on eggs broken by the turnstones. The turnstones apparently broke eggs at a dcvaslating pace. They dashed about in the colony almost in a frenzy, brcaking an cgg npen, snatching a moulhful, dodging a lunge from a royal, and tbcn pccking at another cgg. Betwecn 09:00 20 May, anti 09:00 22 May about 260 cggs wcre brokcn at subcolonies B and C (30 h of daylight). This is about 8.7 cggs per daylight hour. During the 30 rain observation period on 22 May, 6 eggs werc brnken by 6 turnstones, but the colony had been cleared by us. With no broken eggs to feed on, the rate may have been somewhat higher than it would have been wilh many broken cggs. The turnstones did not break open an egg and then finish it before going nn to another as rcported with undcfended eggs (Parkes ct al., op. tit.). Thus tile ineffcctual dcfensc of their eggs by the royals probably rcsulled in more dcslruction than no defcnse at all. Royal Terns are relatively unaggrcssive toward prcdators (Buckley and Buckley, Ibis 114:351, 1972). Those we observed did not seem to recognize turnstones as a thrcal, limiting the defensc of their eggs to an occasional lunge. In contrast, on 12 Junc, Sutlon observed a Herring Gull (Larus argeztatt.s) steal GENERAL NOTES 135 an egg from a small colony of 4 Royal Tern nests on Bird Island. The terns reacted strongly, one chasing the gull out of the colony and actually striking it on the hack. On 30 May, we found no viable Royal Tern eggs on Bird Island. Subcolony 1) on Little Bird had grown to 688 eggs and had then been abandoned. We found another subcolony (E) of 98 eggs also abandoned with many broken eggs. Through June, the Royal Terns continued nesting attempts in small groups nn both islands. Tbey laid 76 eggs in 8 small subcolonies ranging il size from 2 to 26 eggs. All these were ultimately either broken or abandnned. During our ohservations on 30 May, 22 Ruddy Turnstones were nn the beach, but only I was seen feeding on broken eggs in abandoned subcolony D. This eonfirmed our suspieion tbat the turnstones were attracted to the densely packed mass of adult Royal Terns standing in the colony, rather than to the eggs tbemselvcs. During our observation pcriod on 22 May, we twice ohserved that the turnstones did not enter the colony nntil after the royMs had returned and settled down, evcn though they had an npportunity to attack the eggs when undefended. Once the royals abandoned tbc colony, most nf the turnstones ignored it. After subcolony A was abandoned, scores of intact eggs lay com- pletely unprotected for at least 7 days. In the meantime, turnstones were stealing eggs from suhcolonies B and C where adult terns were still present. By eontrast, in 4 of 5 cases discussed by Parkcs ct al. (np. tit.), turnstones were observed taking nnly un- defended eggs. Three other species had nests on the Bird Islands during this period. We found no Least Tern (Sterna albi.t'rons) eggs broken in 200 nests, 7 Gull-billed Tern (Gelocbelido nilotica) eggs broken in 180 nests (3.9%), and 14 Black Skimmer (Rynchops nigra) eggs broken in 816 nests (1.7%). We did not see turn,qoncs break these eggs, but we believe that they did. Gulls were probably not responsible as they usually remove eggs frown the nest, rather than break lhcm in situ. Least and Gull-billed terns arc more aggressive toward prcdators than are Royal Terns, but whether they recognize turnstones as prcdators is not known. Of the 4 species, the rnyals seemed particularly vulnerable lo turnstnne prcdation because they lacked aggression, seemingly failed to recngnize turnstones as predators, and tended to desert the colony en masse when disturbed (Buckley and Buckley, op. cit.).--RolnnT W. LOFTIN, Uttiv. o.[ North Florida, Box 17074, Jacksonville, FL 32216, and SVEW; SUTTON, 4419 Silverwood Lane, Jacksonville, FL 32207. Accepted 19 Jan. 1978.