"'"Table 3. Ixodes uriae from nests and nest material in burrows, N = nymphs.Bird speciesLocality Date of No. No. tickscollection nestsFruterculu urcticu" "" "" "Rissa tridactyla" "" "" "R~st 2-7 May 1978 5 21 =5o'8'?8N" 6-14 Aug. 1968 5 10=4r15~1NRunde 20 June 1967 1 1 = 1 N" 28-31 July 1969 2 0R
In the last week of September 1973 no eggs,larvae or engorged females were found. Dead,dried, adult males were often recorded.The discovery of overwintered ticks amongthe exposed roots in the ceiling of the puffin tunnelsin the grass-turf covered slopes on the islandsof R0St on 5 May, 1978 indicates that tickswander up along the walls in all types of puffintunnels.Ticks were collected by flagging from boththe grassy slopes and the rocks of the puffin colonies.The largest numbers were obtained by loweringthe flag into holes and crevices betweenthe stones. Many ticks were also collected onflags which lay on the ground.In the kittiwake colonies on R0St and Rundeislands, ticks were collected from the nests andfrom the rocky walls just beneath the nests. InMay 1978, overwintered ticks were found understones and in discarded nest material at thefoot of the cliffs, under the kittiwake colonies onVed0y island. In July 1979 we collected ticks atthe same site by flagging and by overturning stones.We found engorged ticks either singly or inaggregations under' the stones and the largestaggregation numbered IQ, 75 nymphs and 8larvae. These ticks must have fallen from the coloniesof kittiwakes, puffins and common guillemotswhich nested above since birds do notnest at the foot of the cliffs.Seasonal variations in the catchability of I. uriaeMay During the first week of May 1978 on R0Stislands only I nymph was captured after threedays of flagging. During this period the weatherwas cold with temperatures of 0- 5°e. The groundwas partially frozen. There were periods ofsnowfall but the intermittent sunshine meltedthe snow '~md warmed the grass tussocks up tolO°e. In the beginning of May, 1975, when theweather was warm, many ticks (nymphs only)were collected by flagging in the puffin colonyon Hernyken island.June In the puffin colony on Lovunden island,2 June 1970, we captured an average of 94nymphs per hour by flagging. In the puffin colonyon Runde island, 3 and 4 June 1978, flaggingyielded from 4 to 108 nymphs per hour.Nymphs only were collected.July During the second week in July 1975,flagging yielded 50 Q and 240 nymphs in thepuffin colony on Runde island. The maximumyield was 13 Q and 58 nymphs per hour. OnR0St islands, during the fourth week of July1979 we collected 2 d , 26 Q and 39 nymphs byflagging for 4 hours. Most ticks were collectedfrom the foot of the bird cliffs where there areno nesting birds.August On the islands of R0st, no ticks werecollected by flagging during the second week ofAugust 1968. However, we did observe a fewticks crawling on rocks.September We did not manage to collect ticksby flagging in the puffin colony on Runde islandduring the last week of September in 1973.Observations on the life cycleThe earliest observation of egg laying are fromJUly 22, 1979 on the islands of R0St. Egg clusterswere found under stones on the same day.The latest observation of mating was on August8, 1968. The egg clusters collected on the sameday included a few eggs which contained veryearly larva stages. On the other hand, on May 7.1978 two egg clusters containing various larvalstages were collected under stones below kittiwakecolony. In one of the clusters we observednewly-hatched larvae which stood on or nearthe egg cases. All egg clusters were found understones or pieces of wood. Most eggs continuedto develop in the laboratory.There were very few active nymphs in the beginningof May 1978 and 1982 when the weatherwas cool (five-day means T. = 0.8°C in1978). On the other hand, when the weatherwas warmer during the first week of May 1975(five-day means T. = 5.0°C), many activenymphs were captured by flagging and many attachednymphs were detected on puffins (Tab.2). Inactive adult males and females were discoveredunder stones and dry plant materials duringthe cool first week of May 1978.During the first week of June, only nymphswere active and collected by flagging in the puffincolony on the island of Lovunden (I 970) andRunde (1978), and collected from puffins andcommon guillemots on R0St in 1980 and 1982.The first time that we observed engorged adultfemales on puffins was on June 10th. Severalfemales (6) were found on kittiWakes, commonguillemots and cormorants during the period23-26 June (Tab. 2).In July we observed active larvae, nymphsand adults on the ground and attached to birds.The proportion oflarvae, nymphs and adults attachedto birds showed large variations, thus nogeneral trends could be seen
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