Importance of scrub–pastureland mosaics for wild-living cats occurrence in a Mediterranean area: implications for the conservation of the wildcat (Felis silvestris)

1. What they did

The European wildcat is threatened in Europe, and conservation advice for the species has focused on forests, based on studies from central and northern Europe. The authors tested whether this holds in the Mediterranean, where scrublands are widespread. They asked whether wildcats in central Spain are linked to forest and tree cover, or to scrubland and other open habitats.

• Scat surveys. Wildcats leave scats in conspicuous places on trails as scent marks. The team walked 78 one-kilometre stretches of trail, spread across four vegetation types, once each in autumn or spring between 1997 and 1999. Each kilometre was split into five 200 m sections, and the number of sections with cat scats (0 to 5) gave an occurrence index.
• Telling the scats apart. Scats were identified by size, colour, smell and contents, and by dry weight to separate them from fox scats. Wildcat and domestic cat scats could not be told apart reliably, so the authors used the term “wild-living cats”. They left out scats longer than 6.1 cm and narrower than 1.4 cm, which are very probably from feral cats.
• Habitat measures. Every 200 m they estimated tree, shrub, open ground and rock cover, tree height and a shelter index within 25 m, and counted rabbit latrines along short side transects. Around each trail (9 km²) they measured forest, pasture, cropland, scrubland and urban cover, watercourses, ruggedness and elevation from maps.
• Checks on the method. Four trails were cleared and resurveyed monthly for six months to see how often scats appear and how long they last. Two of these trails lay inside the home ranges of two radio-tracked wildcats.

2. What they found

• Cat scats were found on 33 of the 78 trail kilometres, 83 scats in all. Where cats were present, an average of 1.5 of the five sections had scats, and there were 2.43 scats per km.
• Occurrence did not differ significantly among the four vegetation types.
• On the regularly checked trails, new scats appeared at about 3.98 per km per month. Nine scats were found on one trail at the first visit, suggesting scats can last about three months before decaying.
• In a trapping campaign during the study, the team caught two wildcats and other predators, but no domestic cats.
• The model explained 13% of the variation. Cats were more likely where shrub cover and shelter were high at the microhabitat scale, and where the landscape was a mosaic of scrubland and pasture with abundant rabbits and watercourses.
• Cats were not linked to areas dominated by forest or tree cover.

3. What they concluded

• Wild-living cats in this Mediterranean area prefer scrub–pastureland mosaics to forest. Vegetation structure, probably through prey and shelter, matters more than vegetation type.
• Cats seem to need two kinds of patches: closed patches for resting and shelter, and open patches such as pasture for hunting. In central Europe forests are the only shelter left, but in the Mediterranean, scrubland can serve as both shelter and hunting ground.
• Scarcity of cats in mountain pine habitat is probably due to poor shrub cover rather than to the forest being coniferous, along with harsher climate and fewer prey.
• Unexplained variation may come from persecution, and from changes in Iberian lynx and rabbit numbers. Gamekeepers, shepherds and naturalists suggest wild-living cats have increased in the past two decades, but there are no data on this.
• Scat surveys are a quick, cost-efficient way to get baseline data on elusive, rare species.

4. How tracking was or was not used

The study rests on a sign survey: finding and identifying cat scats along trails, using size, colour, smell, contents and dry weight to separate them from those of red foxes, stone martens and dogs. Size limits were used to leave out probable feral cat scats. Rabbit abundance was also measured from signs, by counting rabbit latrines. No trailing was reported.

5. Tracker or observer certification

Not reported. The paper does not say who identified the scats or how their skill was checked, although all results depend on telling cat scats from those of other carnivores.

6. Other technologies, skills or innovations

• Radio-tracking of two wildcats, used to place two test trails inside known home ranges.
• A trapping campaign (252 trap-nights) to check whether domestic cats were present.
• Land-use maps with a 121-point grid to measure landscape cover around each trail.

7. Implications for conservation (from the paper)

• European guidance that focuses on forests and farmland may not suit the Mediterranean, which holds most of the wildcat’s European range.
• The authors recommend: (1) protecting scrub–pastureland mosaics, including some as European Community Interest Areas; (2) further studies of these habitats in other Mediterranean areas, including patch size and layout; (3) avoiding extensive removal of scrubland for fire prevention and infrastructure; and (4) managing landscapes to combine scrubland and pasture, and using the main shrub species in reforestation funded by the European Agricultural Policy.