# Dietary shifts of the badger (Meles meles) in Mediterranean woodlands: an opportunistic forager with seasonal specialisms

> In parts of western Europe badgers are famous earthworm eaters, but what do they eat in the cork oak woodlands of southern Portugal? Two years of scats from badger latrines showed a diet built on olives, figs, pears and beetles, with earthworms in only 5 of 450 scats. The badgers ate whatever was around, but switched to olives whenever olives could be found, much of it fruit from traditional farms.

Summary by Kersey Lawrence, Original Wisdom. Updated 9 November 2026. Page: https://www.originalwisdom.com/tracking-literature/2005-rosalino-loureiro-dietary-shifts-badger-meles/

## Citation and access

- **Authors:** Luís Miguel Rosalino, Filipa Loureiro, David W. Macdonald and Margarida Santos-Reis
- **Year published:** 2005
- **Journal or source:** Mammalian Biology
- **Full citation:** Rosalino, L. M., Loureiro, F., Macdonald, D. W. and Santos-Reis, M. 2005. Dietary shifts of the badger (Meles meles) in Mediterranean woodlands: an opportunistic forager with seasonal specialisms. Mammalian Biology 70(1): 12-23.
- **DOI:** 10.1078/1616-5047-00172
- **Access status:** Publisher link only
- **Where to find it:** https://doi.org/10.1078/1616-5047-00172

## Tags

- **Species:** Mammals > Eurasian badger
- **Region:** Europe > Portugal
- **Tracking:** Scat; Sign surveys; Tracking
- **Behaviour and ecology:** Behaviour; Feeding
- **Methods and technology:** Chi-square test; Kolmogorov–Smirnov test; Minimum number of individuals (MNI); Pearson correlation
- **Data type:** New field data
- **Observer qualification:** Not reported
- **Discipline:** Behaviour and ecology
- **Year published:** 2005

## Detailed keywords

- **Species:** Studied: Eurasian badger (Meles meles). Food remains found in scats: fruits of olive (Olea europaea), fig (Ficus carica), pear (Pyrus bourgaeana), cork oak acorns (Quercus suber), blackberry (Rubus ulmifolius), loquat (Eriobotrya japonica), strawberry-tree (Arbutus unedo), plum (Prunus sp.) and tomato (Solanum lycopersicum); beetles (Coleoptera, including ground beetles Carabidae and scarab larvae Scarabaeoidea), crickets and mole crickets (Gryllidae, Gryllotalpidae), grasshoppers (Acrididae), centipedes (Scolopendra sp.), spiders, scorpions, millipedes, woodlice, earwigs, lacewings, flies and ants or wasps (Hymenoptera); voles including Mediterranean pine vole (Microtus duodecimcostatus), Cabrera’s vole (Microtus cabrerae) and southwestern water vole (Arvicola sapidus); wood mouse (Apodemus sylvaticus), brown rat (Rattus norvegicus), mice (Mus sp.), hedgehog (Erinaceus europaeus), greater white-toothed shrew (Crocidura russula), Iberian mole (Talpa occidentalis), lagomorphs; pigeons or doves (Columbiformes), songbirds (Passeriformes) and eggs; lizards (Podarcis hispanica, Psammodromus algirus) and colubrid snakes; fire salamander (Salamandra salamandra), Iberian midwife toad (Alytes cisternasii, spelled “Alyctes” in the paper), western spadefoot (Pelobates cultripes), toads (Bufo sp.) and Perez’s frog (Rana perezi); snails (Gastropoda) and earthworms (Oligochaeta). Common names are ours where the paper gives only scientific names.
- **Location and habitat:** Eastern slope of Serra de Grândola, near the south-western coast of Portugal, 115 km south of Lisbon; study area 66 km². Cork oak “montado” (a semi-natural agro-forest wood-pasture system) with Mediterranean shrub understory (Cistus, Lavandula, Erica) or pasture, valleys with riparian vegetation (poplar, narrow-leaved ash, blackberry), and small, scattered, mostly abandoned orchards and olive groves around farms. Gently undulating, 150 to 270 m above sea level; semi-arid Mediterranean climate, mean 15.6 °C and 500 mm rain a year. Cork oak woodland covers 88.7% of land use.
- **Topics:** diet analysis from scats; feeding ecology; food availability versus consumption; food selection and preference; seasonal and year-to-year dietary shifts; generalist versus specialist feeding (opportunistic forager with seasonal specialisms); trophic niche breadth and overlap; fruit eating (frugivory); insect eating; digestibility correction factors; dependence on traditional agricultural landscapes; rural abandonment; latitude and badger diet.
- **Statistics or models:** percentage of occurrence (PO) and percentage of consumed biomass (PB), with digestibility coefficients from a captive feeding trial; minimum number of individuals or fruits eaten; earthworm numbers estimated from chaetae counts; cumulative frequency curve for sample size; chi-square tests (including Yates’ correction); Shannon-Wiener diversity index (H’) with Hutcheson t-tests; evenness index (J’); Levins niche breadth index (B); Morisita overlap index (C); generalized linear model (Poisson) in S-Plus 2000; Pearson correlation; Kruskal-Wallis test; Kolmogorov-Smirnov test with Lilliefors correction; Jacobs selection index; SPSS 11.5. Inconsistencies in the paper: the 1999 adult arthropod biomass figure is misprinted as “32.8#5%”; Table 2 is titled “General Linear Model” while the text describes a generalized linear (Poisson) model, and Table 2 gives 1 degree of freedom for season and food category although these have several levels; Ciampalini and Lovari is cited as 1985 in the introduction and 1995 in the discussion (1985 in the reference list); the selection index is called D in the methods and J in the results.
- **Data type:** New field data: 450 scats collected fortnightly at all badger latrines found, January 1999 to December 2000; pitfall trapping of ground arthropods once per season over 5 seasons; monthly counts of fallen ripe fruit under sample trees. Digestibility coefficients from an earlier captive feeding trial (Rosalino et al. 2003) and published values.

## Synopsis

### 1. What they did

Eurasian badgers have been called extreme specialists in parts of western Europe, where they feed mostly on one kind of earthworm, while studies in Mediterranean areas disagree on whether they are generalists or specialists. No one had described badger diet in the cork oak “montado” woodlands of the Iberian Peninsula, at the south-western edge of the species’ range. The authors set out to describe how badgers use the food available in these woodlands in Serra de Grândola, south-western Portugal.

- Scats. From January 1999 to December 2000, they checked all badger latrines found in the study area and collected 450 scats every two weeks.

- Diet analysis. In the laboratory they identified food remains (bones, teeth, hairs, feathers, scales, insect parts and seeds) and estimated how many individual animals or fruits had been eaten. Earthworms were counted from their tiny bristles (chaetae) under the microscope. They grouped remains into nine food types and worked out each type’s share of items eaten and of fresh biomass eaten, using correction factors from an earlier feeding trial with a captive badger.

- Food available. They measured ground-dwelling insects and other arthropods with pitfall traps in the four main habitats, once each season, and counted fallen ripe fruits each month under cork oaks, olive trees and pear trees.

- Comparison. They compared diet between seasons and years, measured how broad and varied the diet was, and tested whether badgers ate foods in proportion to their availability.

### 2. What they found

Overall diet

- Badgers ate a wide range of foods, from fruit to mammals, but fruit and arthropods (adults and larvae) made up 97.1% of items eaten and 89.3% of biomass.

- Fruit was the largest part (44.9% of biomass), followed by adult arthropods (29.5%) and arthropod larvae, mainly scarab beetle grubs (14.9%).

- Olives were the main fruit, almost 70% of all fruits eaten, but figs and pears were each as important as olives by biomass (about 12.4% to 12.5% each). Acorns added a little (3.5% of biomass).

- Among adult arthropods, beetles and crickets and grasshoppers (Orthoptera) made up 88% of the number eaten.

- Mammals (mainly voles) gave 5.8% and amphibians 3.9% of biomass. Earthworms appeared in only 5 of the 450 scats.

- Diet breadth was intermediate between a generalist and a specialist.

Changes through the seasons and years

- Diet differed significantly between seasons and between years. In 1999 it was more balanced between fruit and adult arthropods; in 2000 fruit made up over half the biomass eaten.

- Except in winter and spring 1999, fruit dominated the diet, averaging 46.2% of biomass and passing 80% in summer 2000.

- Adult arthropods were most important in spring. Larvae were eaten most in winter and spring 1999 and autumn 2000, when rainfall was high. Mammals were more important in winter 1999 and autumn 2000, and amphibians peaked in summer 1999 and winter 2000.

Availability versus what was eaten

- The pitfall traps caught 8844 arthropods in 15 groups. Fruit and beetle availability varied by season.

- No significant correlation was found between how much of a food was available and how much was eaten.

- Even so, olives were the most eaten food whenever they were available, and the selection index showed olives were strongly preferred in winter and spring and pears in summer.

- Acorns were avoided in every season, although cork oak woodland covers 88.7% of the area.

### 3. What they concluded

- In the montado, badgers are opportunistic foragers with seasonal specialisms: they specialise on olives when olives are available and are otherwise generalists.

- Diet seems to be governed by olive availability, with pears and figs also important, and arthropods eaten regularly, especially when fruit is scarce. Arthropods appear to be eaten opportunistically.

- The lack of a measured link between olives available and olives eaten is probably because fallen olives become buried and were under-counted in the availability surveys, while badgers can still find them buried until the following summer.

- Fruit is rich in sugar but poor in protein; arthropods may make up for this. Acorns may be avoided because tannins make them hard to digest.

- The results fit an earlier model predicting that badgers at this latitude eat mainly plant material and insects, and match other studies from Spain and Italy.

- Most fruits eaten were not wild but came from the traditional multi-use montado system, which shows how much badgers depend on agricultural landscapes.

### 4. How tracking was or was not used

Scat collection depended on finding and monitoring badger latrines (shared toilet sites) across the study area every two weeks, a form of sign survey. The paper does not describe how latrines were found or how scats were confirmed as badger scats. All other identification was laboratory analysis of food remains in the scats.

### 5. Tracker or observer certification

Not reported. The paper does not say who found the latrines or collected the scats.

### 6. Other technologies, skills or innovations

- Identification of prey from bones, teeth, hair, feathers, scales, insect parts and seeds, using reference keys and the authors’ own reference collection.

- Earthworm intake estimated by counting chaetae in scat subsamples under the microscope.

- Biomass correction factors (digestibility coefficients) from a feeding trial with a captive adult male badger fed local foods.

- Baited pitfall traps to measure seasonal arthropod availability, and fallen-fruit counts in fixed square-metre plots under sample trees.

- The authors mention unpublished radio-tracking data: 64% of active badger locations were within 300 m of olive groves or orchards.

### 7. Implications for conservation (from the paper)

- The montado is the major remaining wood-pasture system of Europe, and its future is threatened as rural people leave.

- Badgers here depend on fruit produced by traditional land use, especially olives. As human populations age and the rural economy declines, this traditional land use is degrading, which affects badgers and biodiversity in general.

### 8. Implications for tracking (Original Wisdom's observations)

_These are Original Wisdom's observations, not the authors'._

- Fruit seeds and insect parts dominate badger scats in this habitat, so a tracker in Mediterranean woodland may expect badger latrines full of olive stones, fig and pear seeds and beetle remains rather than the earthworm-rich scats described from parts of western Europe.

## Cite this summary

Lawrence, K. 2026. Summary of: Dietary shifts of the badger (Meles meles) in Mediterranean woodlands: an opportunistic forager with seasonal specialisms (Rosalino and Loureiro et al., 2005). Original Wisdom, Tracking Literature. https://www.originalwisdom.com/tracking-literature/2005-rosalino-loureiro-dietary-shifts-badger-meles/