the diet of the eurasian badger (meles meles) in the republic of ireland gráinne cleary, nicola...

The diet of the Eurasian badger (Meles meles) in the Republic of Ireland

Gráinne Cleary, Nicola Marples, Leigh

Corner & James O’Keefe

Why this is new

• First Republic of Ireland sample

• Results will help with BCG vaccine program

• Large sample size based on stomachs

• Badgers in Ireland have narrow niche breadths

Dietary Niche Breadth BS = (B-1) / (n-1)

Specialist

Generalist

0

1

Section 1The 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

Section 1

What do badgers eat?

Spring

Dietary niche breadth = 0.23

Specialist

Generalist

0

1

Summer

Dietary niche breadth = 0.40

Specialist

Generalist

0

1

Autumn

Dietary niche breadth = 0.26

Specialist

Generalist

0

1

Winter

Dietary niche breadth = 0.44

Specialist

Generalist

0

1

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 Larvae BS = 0.26

Winter Noctuid Larvae BS = 0.44 Frogs

Section 2

Feeding trails

Why does the badger have such a narrow dietary niche breadth?

Food items passed rapidly through the gastrointestinal tract

– After 7 hours only one badger’s 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 vegetation 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