Section 1 The diet during each season is examined followed by the dietary niche breadth Spring Summer Autumn Winter
Section 2 Feeding trails on captive badgers to estimate - passage rate - assimilation efficiency Results help to understand foraging strategy which may be related to dietary niche breadth Section 3 Summary of results
To sum up… Seasonally, the diet is dominated by a couple of food items and therefore the badgers have a narrow niche breadth Spring Tipulid Larvae BS = 0.23 Summer Frogs BS = 0.40 Bees & Wasps Autumn Noctuid LarvaeBS = 0.26 Winter Noctuid LarvaeBS = 0.44 Frogs
Why does the badger have such a narrow dietary niche breadth?
Food items passed rapidly through the gastrointestinal tract –After 7 hours only one badgers stomach still had traces of food –After 16 hours the colon only had traces of selected food items Results showed that…
Stomach and faecal samples suggest that during periods of prey abundance badgers gorge. Therefore food passes rapidly through the gut resulting in low assimilation efficiency and food wastage. Combined with results from dietary analysis…
Other mustelids also have low assimilation efficiency Mink (Mustela vision) – Errington (1967) North American Badger (Taxidea taxus) – Harlow (1981) Weasel (Mustela nivalis) – Moors (1977) Wolverine (Gulo gulo) – Farrell and Wood (1968) Sea Otters (Enhydra lutris) – Iversen (1972)
Why does the badger have such a narrow dietary niche breadth? Species with low absorption efficiency may eat fewer food items = narrow niche breadth Species with high absorption efficiency eat more prey types = broader niche breadth
Section 3 To Sum Up, We tentatively suggest that…
Due to low assimilation efficiency badgers have a narrow dietary niche breadth composed of high-quality foods
Low ingested biomass of earthworms compared to UK This could be due to insect larvae having a higher engery content
Huge intake of v egetation may be involved in slowing down passage time through the gut? Could this result in higher assimilation efficiency?
Acknowledgements Mr. Bill Coleman Dept of Agriculture & Food Dr. Ursula Fogarty Staff at IEC Staff at Abbotstown farm Ms. Alison Boyce Mr. Peter Stafford Ms. Lynsey Stuart Lynsey Stuart