Prey identification of free-ranging domestic cats (Felis catus) from rural and natural areas of Spain through scat analysis

Study Extent

Scats samples were collected in two main regions of Spain, Parque Natural de la Montaña Pelentina (northern Palencia province) and northeastern of the Sierra Nevada National and Natural Park (area consisting of four municipalities of Almeria province, Abla, Abrucena, Ohanes and Las Tres Villas). The first area was located in Montaña Palentina Natural Park, an area composed of small villages surrounded by extensive livestock pastures and natural grasslands. Towns are nearly uninhabited during winter, when only farmers and older people remain, and filled with tourists and families with second homes during summer. Scats in the second area were collected in a non-managed cat colony present on the edge of Abla village, one of the main towns of the study area, and in the isolated cottages found widespread throughout the Natural Park area. Permanent residence within the Natural Park is now rare and cottages are mainly used for temporary stays such as vacations-weekends or crop maintenance. In both places, cat ownership is mainly for rodent control purposes. Finally, opportunistic scat samples were also collected from free-ranging cat owners throughout Spain, who had previously participated as volunteers tracking their cats for the citizen science part of WP4 - Feral Cats project, and who kindly sent us scats from their cats.

Sampling

Scats were mainly collected from places near human settlements (towns, farms, isolated buildings...). For each sample, information associated with the cat that had deposited the excrement was associated when possible in form of two variables. Variable "Cat Type" describes the relationship of the cat with humans and includes the following categories: "Owned": cats that although left free outdoors (entirely or partially), are provided with at least regular food and shelter (veterinary care optional); "Colony cat": cats that live in groups in a specific area and spend their whole time outdoors basically because they do not belong to a specific owner. These may be often supported by caretakers or neighbours that provide them with food but do not consider themselves as owners. Variable "Care level" describes the frequency of food provided by people. It includes the following categories: "Fed": they have feeding guaranteed, either in form of controlled meals or "ad libitum"; "Semifed": they do not receive food in a regular manner or are fed insufficiently with cat food or leftovers and "Probably unfed": individuals found in such isolated or unpopulated places that they are unlikely to receive or have access to food coming from people. Therefore, they would only rely on their catches, although this category is difficult to prove.

Quality Control

The following limitations should be considered when analysing and interpreting these data: - Those remains belonging to species unlikely to have been hunted by a cat in the wild and which were probably of anthropogenic origin were not considered as prey (e.g. fish vertebrae coming from leftovers). - The number of prey consumed is the minimum possible based on body parts found in the scats that allow accounting for different individuals (e.g. mandibles, teeth, number of legs...). More individuals could have been consumed but may have been undetected due to non-individualisable remains such as fur or bones, thus underestimating the prey consumed. - In many cases, we do not know if the scats collected in a specific place belong to several cats or to the same individual.

Method steps

1. Sample processing: Scats were dried at 60 ºC degrees during 48-72h periods to avoid degradation by fungi or insects, as well as the transmission of possible diseases. Then, each sample was left in water for at least one day to hydrate and be able to separate the unidentifiable organic matter from undigested remains with a 500㎛ sieve. Remains such as fur, teeth, bones, mandibles, feathers, scales or hard parts of arthropod exoskeletons were kept in Petri plates for later identification. When content of scats consisted of more than 90% of dry cat food or leftovers, it was reported in "eventRemarks" field.
2. Morphological identification: All specimens were identified to the most specific taxonomic level possible. Mandibles and teeth features were used to assess rodent species or genera following the manual of Roman (2019). Scales from reptiles were usually used to reach order levels. Feathers and calamus remains from birds did not allow us to get further from the class level. Exoskeleton parts from arthropods were analysed by expert entomologists. Generally, the third pair of legs allowed us to identify some specimens at the species level, but most of them were identified at the family level. The variable "identificationMethod" within the dynamic properties in the Occurrence table details the body part found and used in each scat to reach the species identification level. Variables "individualCount" in Occurrence table refers to the minimum number of different individuals of the same species found in the scat. This estimation is done by counting body parts such as mandibles, teeth or legs that can only be present in a certain number in each individual (e.g. there were three upper left mandibles in the scat and one rodent can only have one, it means that at least three individuals were consumed). The variable "sampleSizeValue" in Event table represents the sum of all organisms consumed found in that scat (e.g. two mice and a grasshopper gives an individual count of three).

All specimens were identified to the most specific taxonomic level possible. Mandibles and teeth features were used to assess rodent species or genus. Scales from reptiles were usually used to reach order level. Feathers and calamus remains from birds did not allow us to get further from class level. Exoskeleton parts from arthropods, generally the third pair of legs, allowed us to identify some specimens to the species level, but most of them were identified to family level.

1. Acrididae
   common name: saltamontes rank: family
2. Anacridium aegyptium
   common name: langosta egipcia rank: species
3. Anthidium
   common name: abeja rank: genus
4. Apodemus
   rank: genus
5. Apodemus sylvaticus
   common name: ratón de campo rank: species
6. Arvicola amphibius
   common name: rata topera rank: species
7. Arvicola sapidus
   common name: rata de agua rank: species
8. Aves
   common name: pájaro rank: class
9. Calliptamus
   common name: saltamontes rank: genus
10. Carabidae
    common name: carábido rank: family
11. Coleoptera
    common name: coleóptero rank: order
12. Colubridae
    common name: culebra rank: family
13. Crocidura russula
    common name: musaraña gris rank: species
14. Gryllus
    common name: grillo rank: genus
15. Insecta
    common name: insecto rank: class
16. Iris oratoria
    common name: mantis mediterránea rank: species
17. Iris
    common name: mantis rank: genus
18. Lacertidae
    common name: lagartija rank: family
19. Mammalia
    common name: mamífero rank: class
20. Mantodea
    common name: mantodeos rank: order
21. Melolontha melolontha
    common name: escarabajo sanjuanero rank: species
22. Microtus arvalis
    common name: topillo campesino rank: species
23. Microtus duodecimcostatus
    common name: topillo mediterraneo rank: species
24. Microtus lavernedii
    common name: topillo agreste rank: species
25. Microtus lusitanicus
    common name: topillo lusitano rank: species
26. Microtus
    rank: genus
27. Mus
    rank: genus
28. Mus musculus
    common name: ratón doméstico rank: species
29. Mus spretus
    common name: ratón moruno rank: species
30. Odonata
    common name: libelula rank: order
31. Orthoptera
    common name: ortóptero rank: order
32. Platycleis
    common name: saltamontes longicornios rank: genus
33. Rodentia
    common name: micromamífero rank: order
34. Scarabaeidae
    common name: escarabajos rank: family
35. Segestria florentina
    rank: species
36. Sorex coronatus
    common name: musaraña tricolor rank: species
37. Squamata
    common name: réptil rank: order
38. Talpa europaea
    common name: topo europeo rank: species
39. Tettigoniidae
    common name: saltamontes longicornio rank: family
40. Volucella
    common name: sírfidos rank: genus

The collection is primarily formed by specimens found in free-ranging domestic cat scats from two main regions of Spain, Montaña Palentina Natural Park (north of Palencia province) and the northeastern of the Sierra Nevada National and Natural Park, in the province of Almería. It also contains specimens from free-ranging cat owners throughout Spain who kindly sent us scats from their cats.