Table C- Owl Pellet Species Identification SPECIES (scientific name, common name) Mierotus agrestis, Field Vole How did you make the ID? (also write the letter of the keys used to ID the species) Key #2-B Soricidae/Sorex , Common Shrew Key #2 Number of individuals in pellet Diet Average Mass of organism grass stems, green leaves, roots 3 40g beetles, grasshoppers, spiders, seeds, roots 2 4g Table D - Class Owl Pellet Data Species (scientific name, common name) Field Vole B Average biomass for species (g) Total Number of individuals found in all pellets BT Total dietary Biomass species %B Percentage contributes to owl’ Biomass in owl’s s diet diet 40 4 160 5.58% 150 9 1350 47.12% House Mouse 18 2 36 1.26% Harvest Mouse 12 1 12 0.42% Wood mouse 40 5 200 6.98% Pocket Mouse 25 4 100 3.49% Rat 150 4 600 20.94% Bird 50 2 100 3.49% 4 3 12 0.42% Mole 55 5 275 9.60% Bat 20 1 20 0.70% 2865 100.00% Pocket Gophers Shrew Trophic Level I- Insectivore H- Herbivore O- Omnivore C-Carnivore Table E - Owl’s diet by Percent Biomass: Trophic Level Percent Biomass Herbivores 52.71% Omnivores 36.58% Carnivores 10.72% Table F - Average Owl Pellet Contents Species (Common Name) TC = Total Number of individuals of each species class found ALL pellets N = Average Number of individuals of species found in pellet (N = TC/P) P= Total Number of Pellets Examined Field Vole 4 11 0.36 Pocket Gophers 9 11 0.8 House Mouse 2 11 0.1818181818 Harvest Mouse 1 11 0.09090909091 Wood Mouse 5 11 0.4545454545 Pocket Mouse 4 11 0.3636363636 Rat 4 11 0.3636363636 Bird 2 11 0.1818181818 Common Shrew 3 11 0.2727272727 Mole 5 11 0.4545454545 Bat 1 11 0.09090909091 TABLE G – Total Prey Consumed Annually by Owl Species (Common Name) TY (Total Number of each N D (Total species eaten (Avg. Number Number eaten of this species per day) D = 2.5 per year) TY = 365 x D found per pellet) xN 0.36 0.91 331.82 Pocket Gophers 0.82 2.05 746.59 House Mouse 0.18 0.45 165.91 Harvest Mouse 0.09 0.23 82.95 Wood Mouse 0.00 0.00 0.00 Pocket Mouse 0.00 0.00 0.00 Rat 0.00 0.00 0.00 Bird 0.00 0.00 0.00 Common Shrew 0.27 0.68 248.86 Field Vole Mole 0 0 0 Bat 0 0 0 P y = Total Number of Prey Items Eaten Per Year PY= 1576.14 TABLE H – Total Biomass Needed to Support Owl for Year Species (Common Name) TY (Number eaten per year) 331.82 Field Vole Pocket Gophers 746.59 B (Average Biomass for species) (g) M (Average biomass of each species (kg)) (M= B / 1000) MP (Total Biomass of Producers required to MC support each (Total Biomass species)(kg) of Consumer ( MP = MC x Species eaten B,) per Year)(kg) (B =10, 50 or ( MC = M x TY) 100) 40 0.04 13.27 132.73 150 0.15 111.99 1119.89 House Mouse 165.91 18 0.018 2.99 149.32 Harvest Mouse 82.95 12 0.012 1.00 49.77 Wood Mouse 0 0 0 0.00 0.00 Pocket Mouse 0 0 0 0.00 0.00 Rat 0 0 0 0.00 0.00 Bird 0 0 0 0.00 0.00 Common Shrew 248.86 4 0.004 1.00 99.55 Mole 0 0 0 0 0 Bat 0 0 0 0 0 T = Total Biomass of Consumers and Producers (kg) TMc = 130.24 Table I - Total Annual Biomass By Trophic Level Trophic Level Annual Biomass (kg) T1 1551.25 T2 125.26 T3 4.98 TMP= 1551.25 T4 - Owl 1 Table J - Numbers by Trophic Level (Per year) Trophic Level Numbers Eaten per Year T1 n/a T2 1078 T3 498 T4 - Owl 1 Table C- Owl Pellet Species Identification SPECIES (scientific name, common name) Mierotus agrestis, Field Vole How did you make the ID? (also write the letter of the keys used to ID the species) Key #2-B Soricidae/Sorex , Common Shrew Key #2 Number of individuals in pellet Diet Average Mass of organism grass stems, green leaves, roots 3 40g beetles, grasshoppers, spiders, seeds, roots 2 4g Table D - Class Owl Pellet Data Species (scientific name, common name) Field Vole B Average biomass for species (g) Total Number of individuals found in all pellets BT Total dietary Biomass species %B Percentage contributes to owl’ Biomass in owl’s s diet diet 40 43 1720 79.93% 150 2 300 13.94% House Mouse 18 4 72 3.35% Harvest Mouse 12 3 36 1.67% Wood mouse 40 0 0 0.00% Pocket Mouse 25 0 0 0 Rat 150 0 0 0.00% Bird 50 0 0 0.00% 4 6 24 1.12% 55 0 0 0 0 0 0 0 Pocket Gophers Shrew Mole Bat 2152 Trophic Level I- Insectivore H- Herbivore O- Omnivore C-Carnivore Table E - Owl’s diet by Percent Biomass: Trophic Level Percent Biomass Herbivores 93.87% Omnivores 5.02% Carnivores 1.12% Table F - Average Owl Pellet Contents Species (Common Name) TC = Total Number of individuals of each species class found ALL pellets Field Vole N = Average Number of individuals of species found in pellet (N = TC/P) P= Total Number of Pellets Examined 43 20 2.15 Pocket Gophers 2 20 0.1 House Mouse 4 20 0.2 Harvest Mouse 3 20 0.15 Wood Mouse 0 20 Pocket Mouse 0 20 Rat 0 20 Bird 0 20 Common Shrew 6 20 Mole 0 20 Bat 0 20 0.3 TABLE G – Total Prey Consumed Annually by Owl Species (Common Name) TY (Total Number of each N D (Total species eaten (Avg. Number Number eaten of this species per day) D = 2.5 per year) TY = 365 x D found per pellet) xN 2.15 5.38 1961.88 Pocket Gophers 0.10 0.25 91.25 House Mouse 0.20 0.50 182.50 Harvest Mouse 0.15 0.38 136.88 Wood Mouse 0.00 0.00 0.00 Pocket Mouse 0.00 0.00 0.00 Rat 0.00 0.00 0.00 Bird 0.00 0.00 0.00 Common Shrew 0.30 0.75 273.75 Field Vole Mole 0 0 0 Bat 0 0 0 P y = Total Number of Prey Items Eaten Per Year PY= 2646.25 TABLE H – Total Biomass Needed to Support Owl for Year Species (Common Name) TY (Number eaten per year) 1961.88 Field Vole Pocket Gophers 91.25 B (Average Biomass for species) (g) M (Average biomass of each species (kg)) (M= B / 1000) MP (Total Biomass of Producers required to MC support each (Total Biomass species)(kg) of Consumer ( MP = MC x Species eaten B,) per Year)(kg) (B =10, 50 or ( MC = M x TY) 100) 40 0.04 78.48 784.75 150 0.15 13.69 136.88 House Mouse 182.50 18 0.018 3.29 164.25 Harvest Mouse 136.88 12 0.012 1.64 82.13 Wood Mouse 0 0 0 0.00 0.00 Pocket Mouse 0 0 0 0.00 0.00 Rat 0 0 0 0.00 0.00 Bird 0 0 0 0.00 0.00 Common Shrew 273.75 4 0.004 1.10 109.50 Mole 0 0 0 0 0 Bat 0 0 0 0 0 T = Total Biomass of Consumers and Producers (kg) TMc = 98.19 Table I - Total Annual Biomass By Trophic Level Trophic Level Annual Biomass (kg) T1 1277.50 T2 92.16 T3 6.02 TMP= 1277.50 T4 - Owl 1 Table J - Numbers by Trophic Level (Per year) Trophic Level Numbers Eaten per Year T1 n/a T2 2053 T3 593 T4 - Owl 1