# Fallow Deer and Wild Boar Pellet Group Disappearance in a Mediterranean Area

> How long does dung stay on the ground? In an Italian coastal park, researchers set out fresh fallow deer and wild boar dung every season and watched it disappear. In winter almost all of it lasted a month, but in autumn dung beetles and rain removed 88% of the deer dung within a month, with beetles arriving at some pellets in under an hour.

Summary by Kersey Lawrence, Original Wisdom. Updated 9 November 2026. Page: https://www.originalwisdom.com/tracking-literature/1998-massei-bacon-fallow-deer-wild-boar/

## Citation and access

- **Authors:** Giovanna Massei, Philip Bacon and Peter V. Genov
- **Year published:** 1998
- **Journal or source:** The Journal of Wildlife Management
- **Full citation:** Massei, G., Bacon, P. and Genov, P. V. 1998. Fallow deer and wild boar pellet group disappearance in a Mediterranean area. The Journal of Wildlife Management 62(3): 1086–1094.
- **DOI:** 10.2307/3802561
- **Access status:** Publisher link only
- **Where to find it:** https://doi.org/10.2307/3802561

## Tags

- **Species:** Invertebrates > Dung beetle; Mammals > Fallow deer; Mammals > Wild boar
- **Region:** Europe > Italy
- **Tracking:** Feeding signs; Scat; Sign surveys; Spoor age estimation; Tracking
- **Behaviour and ecology:** Behaviour; Feeding
- **Methods and technology:** Chi-square test; Descriptive statistics; Detectability; Population estimation
- **Data type:** New field data
- **Observer qualification:** Not reported
- **Discipline:** Behaviour and ecology; Wildlife tracking
- **Year published:** 1998

## Detailed keywords

- **Species:** Studied: pellet groups (dung) of fallow deer (Dama dama) and wild boar (Sus scrofa). Other animals affecting the dung: dung beetles (Geotrupes, Aphodius), which buried or broke up pellets, and wild boar, whose rooting disturbed fallow deer pellets. Mentioned for comparison: roe deer (Capreolus capreolus). No large predators were present in the area.
- **Location and habitat:** Maremma Natural Park, west coast of central Italy (42°39’N, 11°05’E), 0 to 417 m, Mediterranean climate (mean 6°C in February to 23°C in July; 500 to 750 mm of rain a year, mainly in spring and autumn). Four habitats: maquis scrub (holm oak Quercus ilex, strawberry tree Arbutus unedo, Phillyrea latifolia), pinewood (Pinus pinea), sand dunes with Juniperus oxycedrus, and meadows of grasses and sedges. About 14.2 fallow deer per km² (1990) and 12.8 wild boar per km² (March 1993); no wild boar hunting and very limited deer shooting.
- **Topics:** pellet group counts; dung (scat) decay and disappearance rates; dung persistence; clearance-plot method; correction factors for pellet counts; seasonal and habitat effects; dung beetles (coprophagous insects); wild boar rooting; rain; ungulate density estimation; timing of pellet surveys; age of scat collected for diet analysis.
- **Statistics or models:** General linear model (GLM) on arcsine-transformed numbers of pellets remaining per fallow deer group; log-linear models (chi-square statistics) for numbers of groups disappeared after 1 and 3 months; proportions missing with asymmetrical 95% confidence limits; mean persistence with 95% confidence limits (program EX, Krebs 1989); MINITAB. Inconsistencies in the paper: (1) habitat effect on fallow deer pellets at 3 months is given as F(3,9) = 4.98, P > 0.05, although an F of 4.98 on 3 and 9 degrees of freedom would be below 0.05; (2) some chi-square values for interactions are printed with 3 degrees of freedom where 9 would be expected; (3) the Management implications give losses as “22 ± 0.08%” and “1 ± 0.03%”, while Table 1 and Table 2 give 95% confidence intervals of 0.16 and 0.07; (4) mean fallow deer persistence in autumn is given as 12.7 ± 23.4 days (error larger than the mean).
- **Data type:** New field data: experimental pellet groups placed at the start of each season, January 1993 to January 1994, checked 1 week after placement and then every 3 weeks.

## Synopsis

### 1. What they did

Counting dung pellet groups is a common way to estimate how many deer or wild boar live in an area, especially where animals are hard to see. The count only works if researchers know how fast dung disappears between visits. No one had measured this in a Mediterranean climate, or for wild boar and fallow deer at all.

In Maremma Natural Park on the coast of central Italy, the researchers collected fresh dung and set it out themselves:

- Fresh dung. Fallow deer pellets came from a 40-ha enclosure where cleared transects were checked every 2 days, so they were no more than 48 hours old. Wild boar dung came from heavily used sites visited daily and was judged to be no more than 2 days old. All dung was refrigerated until placed.

- Experimental groups. Fallow deer groups held about 64 pellets on average, so groups of 60 pellets were used. Wild boar groups held about 4.5 pellets of varying size and shape, so whole natural groups were used.

- Placement. At the start of each season (January 1993 to January 1994), they placed 30 groups of each species, 7 m apart along a random transect, in each of four habitats: maquis scrub, pinewood, sand dunes and meadow. That is 120 groups per species per season.

- Checks. They visited the groups 1 week after placement and then every 3 weeks until about half had gone from at least two habitats. A fallow deer group counted as gone when 5 or fewer pellets were left; a wild boar group when no visible sign remained. They also recorded dung beetle burial and rooting by wild boar.

### 2. What they found

Season mattered more than habitat

- For both species, dung disappeared slowly in winter, spring and summer, and much faster in autumn.

- Season explained most of the variation in fallow deer pellets remaining (50.6% after 1 month, 14.7% after 3 months); habitat explained only about 5%.

After 1 month

- Winter: about 99% of fallow deer groups and 100% of wild boar groups were still there.

- Autumn: 88% of fallow deer groups had gone, but only 5% of wild boar groups.

- After 1 week, no groups of either species had gone in winter or spring; fallow deer losses began only in autumn.

After 3 months

- About 78% of groups of both species were still there after a winter start.

- In autumn, all fallow deer groups had gone, and 44% of wild boar groups.

- Fallow deer dung disappeared faster than wild boar dung overall.

How long dung lasted (mean persistence)

- Fallow deer: longest in winter (about 164 days), shortest in autumn (about 13 days). Within each season, groups lasted longest in the dunes.

- Wild boar: longest in spring (about 218 days), shortest in autumn (about 62 days).

What removed the dung

- Dung beetles buried fallow deer pellets in 92 of 480 groups, 69% of them in autumn. In autumn, beetles arrived at some pellets less than 1 hour after placement.

- Beetles buried whole fallow deer pellets, but broke wild boar pellets into pieces first.

- Wild boar rooting sped up the loss of fallow deer pellets in 69 groups, mostly in summer and autumn and mostly in maquis.

### 3. What they concluded

- In Mediterranean areas, pellet counts for both species are best done in winter, when dung disappears most slowly, and dung should be counted over a 1-month period.

- Their correction factors are maximum values, because all their dung was set out on day zero; dung found in the wild will include younger groups, so the factors will slightly overestimate the number of groups produced.

- Rain and dung beetles probably explain the fast loss in autumn, but their effects could not be separated. In 1993, 80% of the year’s rain fell between September and December, and wild boar density was very high, so rooting may have had an unusually large effect.

- Wild boar dung may last longer because boar are not ruminants: their dung holds partly undigested food and more fibre, while fallow deer dung is finely digested. Pellet size may also play a part.

- Autumn pellet counts should be used with great caution, for example to judge habitat use. Where ungulates are scarce, empty plots in autumn cannot show whether no dung was dropped or it had already disappeared.

- Dung collected in autumn for diet studies is very likely less than 1 month old.

- The study covered only 1 year and 1 site; more sites and years are needed to know whether the figures apply generally.

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

The study is about one kind of sign: dung. The researchers judged dung freshness when collecting it, then followed set-out dung over time to see how long it stayed recognisable, and recorded signs of what removed it (dung beetle burial and wild boar rooting). No trailing or footprint work was involved.

### 5. Tracker or observer certification

Not reported. Nothing is said about who collected, aged or checked the dung. The age of the wild boar dung (2 days or less) was judged at collection.

### 6. Other technologies, skills or innovations

- An experimental design with known-age dung placed at the same time in four habitats in every season.

- Correction factors with 95% confidence limits for the proportion of dung groups likely to have gone after 1 and 3 months, by season and habitat.

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

- Wild boar and fallow deer can reach high densities and damage crops and woodland, so managers need reliable local density estimates, often from pellet counts.

- In Mediterranean regions, the timing of pellet counts strongly affects their reliability: winter counts lose the least dung, while autumn counts can miss most fallow deer dung within a month.

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

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

- How long dung lasts depends heavily on season and on what lives there. In this Mediterranean area, fallow deer dung could vanish within weeks in autumn but last for months in winter, so the same-looking dung can mean very different ages in different seasons.

- Dung beetles and rooting animals can remove or break up dung quickly, which matters when judging whether an animal has been in an area recently or not at all.

## Cite this summary

Lawrence, K. 2026. Summary of: Fallow Deer and Wild Boar Pellet Group Disappearance in a Mediterranean Area (Massei and Bacon et al., 1998). Original Wisdom, Tracking Literature. https://www.originalwisdom.com/tracking-literature/1998-massei-bacon-fallow-deer-wild-boar/