_id Worksheet WS_Description Field Description Type Units 1 Lemming winter nests Winter nests found in searches of trapping grids each summer, and indications of predation by ermine Year Summer when nest was found (1994-1997) Text yyyy 2 Lemming winter nests Winter nests found in searches of trapping grids each summer, and indications of predation by ermine Grid Trapping grid, 1-7. Grid 4 was protected from predators; grids 1-3 were not. In 1994 we searched three additional unprotected grids (5-7) in upland habitat. Text "" 3 Lemming winter nests Winter nests found in searches of trapping grids each summer, and indications of predation by ermine ErmineOcc Nest occupied by ermine, i.e. lined with fur and containing ermine scats. 0=No, 1=Yes Numeric 0 or 1 4 Lemming winter nests Winter nests found in searches of trapping grids each summer, and indications of predation by ermine InclOtherSign Nest occupied or with other signs of ermine predation (a lemming skin in 1996 and tufts of fur in 1997). 0=No, 1=Yes Numeric 0 or 1 5 Lemming winter nests Winter nests found in searches of trapping grids each summer, and indications of predation by ermine Transect width Width of transects walked by observers on trapping grids. 3 m in 1994 and 1995; 6 m in 1996 and 1997 Numeric m 6 Male Dicro reprod cond Reproductive condition of live-captured male Dicrostonyx Year Year captured, 1995-1997 Text yyyy 7 Male Dicro reprod cond Reproductive condition of live-captured male Dicrostonyx Grid Trapping grid, 1-4. Grid 4 was protected from predators; grids 1-3 were not Text "" 8 Male Dicro reprod cond Reproductive condition of live-captured male Dicrostonyx Tag Ear tag number. An individual may have been captured in more than one period within a year, and possibly in more than one year Text "" 9 Male Dicro reprod cond Reproductive condition of live-captured male Dicrostonyx WtClass Weight class. Juvenile <25 g, Subadult 25-49 g, Adult ?50g Text "" 10 Male Dicro reprod cond Reproductive condition of live-captured male Dicrostonyx MaleRep Reproductive condition (0 not in reproductive condition (abdominal testes), 1 in reproductive condition (scrotal testes) Numeric 0 or 1 11 Male Dicro reprod cond Reproductive condition of live-captured male Dicrostonyx Period Period of year when captured: June, JunJul, JulAug, Aug Text "" 12 Female Dicro reprod cond Reproductive condition of live-captured female Dicrostonyx Year Year captured, 1995-1997 Text yyyy 13 Female Dicro reprod cond Reproductive condition of live-captured female Dicrostonyx Grid Trapping grid, 1-4. Grid 4 was protected from predators; grids 1-3 were not Text "" 14 Female Dicro reprod cond Reproductive condition of live-captured female Dicrostonyx Tag Ear tag number. An individual may have been captured in more than one period within a year, and possibly in more than one year Text "" 15 Female Dicro reprod cond Reproductive condition of live-captured female Dicrostonyx WtClass Weight class. Juvenile <25 g, Subadult 25-49 g, Adult ?50g Text "" 16 Female Dicro reprod cond Reproductive condition of live-captured female Dicrostonyx FemaleRep Reproductive condition (0 not in reproductive condition (closed pubic symphysis, nipples not enlarged, not obviously pregnant), 1 in reproductive condition (open pubic symphysis or enlarged nipples or obviously pregnant) Numeric 0 or 1 17 Female Dicro reprod cond Reproductive condition of live-captured female Dicrostonyx Period Period of year when captured: June, JunJul, JulAug, Aug Text "" 18 Oestrus Dicro Oestrus of live-captured Dicrostonyx. Recorded only in 1997 and July and August 1996. Year Year captured, 1996-1997 Text yyyy 19 Oestrus Dicro Oestrus of live-captured Dicrostonyx. Recorded only in 1997 and July and August 1996. Grid Trapping grid, 1-4. Grid 4 was protected from predators; grids 1-3 were not Text "" 20 Oestrus Dicro Oestrus of live-captured Dicrostonyx. Recorded only in 1997 and July and August 1996. Tag Ear tag number. An individual may have been captured in more than one period within a year, and possibly in more than one year Text "" 21 Oestrus Dicro Oestrus of live-captured Dicrostonyx. Recorded only in 1997 and July and August 1996. WtClass Weight class. Juvenile <25 g, Subadult 25-49 g, Adult ?50g Text "" 22 Oestrus Dicro Oestrus of live-captured Dicrostonyx. Recorded only in 1997 and July and August 1996. FemaleRep Oestrus condition (0 not in oestrus (imperforate vagina), 1 in oestrus (perforate vagina) Numeric 0 or 1 23 Oestrus Dicro Oestrus of live-captured Dicrostonyx. Recorded only in 1997 and July and August 1996. Period Period of year when captured: June, JunJul, JulAug, Aug Text "" 24 Dicrostonyx body mass Body mass of live-captured Dicrostonyx Year Year captured, 1995-1997 Text yyyy 25 Dicrostonyx body mass Body mass of live-captured Dicrostonyx Grid Trapping grid, 1-3. These three grids were not protected from predators Text "" 26 Dicrostonyx body mass Body mass of live-captured Dicrostonyx Tag Ear tag number. An individual may have been captured in more than one period within a year, and possibly in more than one year Text "" 27 Dicrostonyx body mass Body mass of live-captured Dicrostonyx Period Period of year when captured: June, JunJul, JulAug, Aug Text "" 28 Dicrostonyx body mass Body mass of live-captured Dicrostonyx Mass Body mass Numeric g 29 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) Year Year scat collected (1994-1997) Text yyyy 30 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) ScatID Scat identifier, not unique between years Text "" 31 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) DateCollected Day and month scat was collected Text dd-mmm 32 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) DenID "Name of den where scat was collected. If not from a den, then ""N""" Text "" 33 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) AdJuv Adult (A) or juvenile (J) fox. For scats collected at dens in July and August 1995 and 1996, classification was based on scat diameter. Other scats were assumed to be from adults. Text "" 34 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) Period Period of year when scat was collected. Format is yyyy-n. n=0 means a winter scat collected from snow in spring. Within a year, period n=1-4 corresponds to dates on columns of Supplementary Table S1. Text "" 35 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) ScatWt Weight of dried scat Numeric g 36 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) MLemBones Mass of lemming bones in scat Numeric g 37 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) MGrSqBones Mass of ground squirrel bones in scat Numeric g 38 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) MHare Mass of arctic hare bones in scat Numeric g 39 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) MLbird Mass of bones from large bird (anseriform, galliform) in scat Numeric g 40 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) MSbird Mass of bones from small bird (passeriform, charadriiform) in scat Numeric g 41 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) MEggshell Mass of eggshell in scat Numeric g 42 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) MInsect Mass of insect parts in scat Numeric g 43 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) MVeg Mass of vegetation in scat Numeric g 44 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) MShrew Mass of shrew bones in scat Numeric g 45 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) MInvert Mass of invertebrate (non-insect) exoskeleton in scat Numeric g 46 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) MParasite Mass of parasites in scat Numeric g 47 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) MCaribou Mass of caribou hair in scat Numeric g 48 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) MUnid Mass of unidentified material in scat Numeric g 49 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) MSynthetic Mass of synthetic material in scat Numeric g 50 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) UnidBoneSize Size of unidentified bones. A taxon with similarly sized bones (Gr sq = ground squirrel, Lbird = large bird) or Sm=small. Text "" 51 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) Comment Notes on den, freshness, eggshell, or other material Text "" 52 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) MRemainder "Mass of ""remainder"" without above items " Numeric g 53 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) PctMicrotineFur Microtine fur in remainder Numeric Percentage 54 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) PctGrSqFur Ground squirrel fur in remainder Numeric Percentage 55 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) PctLfeath Large feathers in remainder (anseriform, galliform) Numeric Percentage 56 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) PctSfeath Small feathers in remainder (passeriform, charadriiform) Numeric Percentage 57 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) PctVeg Vegetation in remainder Numeric Percentage 58 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) PctInorg Inorganic material in remainder Numeric Percentage 59 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) PctHare Hare fur in remainder Numeric Percentage 60 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) PctFox Fox fur in remainder Numeric Percentage 61 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) PctEgg Eggshell in remainder Numeric Percentage 62 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) PctInsect Insect parts in remainder Numeric Percentage 63 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) PctUnidTissue Unidentified tissue in remainder Numeric Percentage 64 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) Note Notes on unidentified tissue Text "" 65 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) NTeethDicro Number of Dicrostonyx molar teeth Numeric Count 66 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) NTeethLemmus Number of Lemmus molar teeth Numeric Count 67 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) NumDicro Minimum number of Dicrostonyx in scat, based on teeth Numeric Count 68 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) NumLemmus Minimum number of Lemmus in scat, based on teeth Numeric Count 69 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) NumLemOther Minimum number of lemmings (species not identifiable) in scat, based on other contents (fur, bones, feet, tails) Numeric Count 70 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) NumDicroOther Minimum number of Dicrostonyx in scat, based on teeth and other contents (fur, bones, feet, tails) Numeric Count 71 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) NumLemmusOther Minimum number of Lemmus in scat, based on teeth and other contents (fur, bones, feet, tails) Numeric Count 72 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) Ulna1 Length of ulna 1 in scat Numeric mm 73 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) Ulna2 Length of ulna 2 in scat Numeric mm 74 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) UpperMolarRow1 Length of upper molar row 1 in scat Numeric mm 75 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) UpperMolarRow2 Length of upper molar row 2 in scat Numeric mm 76 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) LowerMolarRow1 Length of lower molar row 1 in scat Numeric mm 77 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) LowerMolarRow2 Length of lower molar row 2 in scat Numeric mm 78 Fox scats Analysis of fox scat contents (Methods are in Supplementary Calculations S2) SpMolars Species of molar row(s), D (Dicrostonyx) or L (Lemmus) Text "" 79 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) Species Predatory bird species. GLGU, PEFA, RLHA, SACR, SEOW, SNOW refer respectively to glaucous gull, peregrine falcon, rough-legged hawk, sandhill crane, short-eared owl, snowy owl Text "" 80 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) Year Year pellet collected (1994-1997) Text yyyy 81 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) PelletID Pellet identifier, not unique between years Text "" 82 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) DateCollected Day and month pellet was collected Text dd-mmm 83 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) FromNest Was pellet collected from a nest, Y or N Text "" 84 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) Location Location where collected, including whether on snow Text "" 85 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) Comment Comment on pellet freshness, etc. Text "" 86 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) NumDicro Minimum number of Dicrostonyx, based on teeth Numeric Count 87 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) NumLemmus Minimum number of Lemmus, based on teeth Numeric Count 88 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) NumMicrotus Minimum number of Microtus oeconomus voles, based on teeth Numeric Count 89 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) NumSorex Minimum number of Sorex cinereus shrews, based on teeth Numeric Count 90 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) PADicro Presence (1) or absence (0) of Dicrostonyx, based on teeth, fur, claws Numeric 0 or 1 91 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) PALemmus Presence (1) or absence (0) of Lemmus, based on teeth Numeric 0 or 1 92 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) PMicrotus Presence (1) of Microtus oeconomus voles, based on teeth Numeric 1 or blank 93 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) PSorex Presence (1) of Sorex cinereus shrews, based on teeth Numeric 1 or blank 94 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) GrSq Presence (1) of ground squirrel remains Numeric 1 or blank 95 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) Bird Presence (1) of bird remains Numeric 1 or blank 96 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) Eggshell Presence (1) of eggshell Numeric 1 or blank 97 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) Insects Presence (1) of insect remains Numeric 1 or blank 98 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) Veg Presence (1) of vegetation Numeric 1 or blank 99 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) Inorg Presence (1) of inorganic material Numeric 1 or blank 100 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) Clamshell Presence (1) of clam shell Numeric 1 or blank 101 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) Unid Presence (1) of unidentified material Numeric 1 or blank 102 Avian predator pellets Analysis of pellets from avian predators (Methods are in Supplementary Calculations S3) Claws Presence (1) of claws Numeric 1 or blank