Natural History Sciences. Atti Soc. it. Sci. nat. Museo civ. Stor. nat. Milano, 8 (2): 3-10, 2021 DOI: 10.4081/nhs.2021.512 Small mammals from barn owl Tyto alba pellets in a Mediterranean agroforestry landscape of central Italy Vincenzo Ferri1, Paolo Crescia1, Stefano Celletti1, Christiana Soccini1, Corrado Battisti2* 1 GNML Gruppo Naturalistico della Maremma Laziale, vicolo della Petrara, 4, 01016 Tarquinia, Italia. E-mail: associazione.gnml@gmail.com 2 “Torre Flavia” Long Term Ecological Research (LTER) Station, Città Metropolitana di Roma, via Ribotta, 41, 00143 Roma, Italia. * Corresponding author: c.battisti@cittametropolitanaroma.gov.it © 2021 Vincenzo Ferri, Paolo Crescia, Stefano Celletti, Christiana Soccini, Corrado Battisti Received for publication: 6 January 2021 Accepted for publication: 7 July 2021 Online publication: 29 October 2021 Abstract - In order to investigate diversity patterns and similari- ties in the small mammal communities of an agroforestry landscape in western central Italy (Maremma of Lazio), we analyzed, in a mul- tivariate setting (Cluster analysis, DCA-Detrended Correspondence Analysis), the prey content of barn owl Tyto alba pellets collected along one year in five sampling sites. Small mammal communities were com- posed by guilds typical of habitats included in agroforestry landscapes (croplands and mosaics, forests and ecotones, wet habitats and synan- thropic ones). Since landscape matrices were characterized almost eve- rywhere by croplands, typical agro-ecosystem species (Apodemus cfr. sylvaticus, Microtus savii, Mus domesticus and Soricidae) dominated in the majority of the collecting sites. The statistical analyses show how small changes in land use and cover can explain the faunal differences between sites, with the occasional presence of Arvicola italicus in wet habitats, and of Muscardinus avellanarius and Sorex samniticus in sites dominated by forest or agroforestry ecotones. Communities recorded in sites characterized by wet and forest hab- itats showed a higher distance from the others, dominated by croplands. Communities occurring in landscapes with the lowest habitat diversity showed also the lowest species diversity. Key words: Agroforestry landscapes, equitability, habitat diver- sity, species diversity, species richness. Riassunto - Piccoli mammiferi da borre di barbagianni (Tyto alba) in un paesaggio agroforestale mediterraneo dell’Italia centrale. Per indagare i pattern di diversità e di somiglianza nelle piccole comunità di mammiferi di un paesaggio agroforestale dell’Italia centro- occidentale (Maremma del Lazio), abbiamo analizzato, in un contesto di analisi multivariata (Cluster analysis, DCA-Detrended Correspon- dence analysis), il contenuto di prede in borre di barbagianni Tyto alba raccolte durante un anno in cinque siti di campionamento. Le comunità di piccoli mammiferi erano composte da gilde tipi- che degli ambienti compresi nei paesaggi agroforestali (terreni colti- vati e mosaici, foreste ed ecotoni, zone umide e habitat sinantropici). Poiché le matrici paesaggistiche erano caratterizzate quasi ovunque da terreni coltivati, le specie tipiche dell’agroecosistema (Apodemus cfr. sylvaticus, Microtus savii, Mus domesticus e Soricidae) dominano nella maggior parte dei siti di raccolta. Le analisi statistiche eviden- ziano come piccoli cambiamenti nella copertura o nell’uso del suolo possono spiegare le differenze faunistiche tra siti, con Arvicola italicus occasionalmente presente negli ambienti umidi e Muscardinus avella- narius e Sorex samniticus nei siti dominati dalla foresta o negli ecotoni agro-forestali. I siti con la più bassa eterogeneità ambientale (=diver- sità di habitat) hanno mostrato anche la più bassa diversità di specie. La composizione e la dominanza di specifiche tipologie d’uso/coper- tura del suolo nelle aree limitrofe ai siti di campionamento spiegano le somiglianze tra le comunità di piccoli mammiferi. In particolare, due siti (uno inserito in un paesaggio a matrice forestale dominante, l’al- tro caratterizzato da bassa diversità ambientale) hanno evidenziato una maggiore dissimilarità strutturale dagli altri. Parole chiave: Diversità ambientale, diversità di specie, equiripar- tizione, paesaggio agroforestale, ricchezza di specie. IntRoductIon Worldwide, communities of small mammals are indi- rectly studied using owl’s (Aves: Strigiformes) pellets in- cluding remnants (mainly skulls and jaws) of these preys (e.g., Contoli & Sammuri, 1978; Bonvicino & Bezerra, 2003). Using this technique, a large amount of data is quickly available, although some limitation of this appro- ach has been highlighted (Yom-Tov & Wool, 1997; An- drade et al., 2016). For example, since some owl species are stenoecious, inhabiting only specific habitats (as in the case of barn owl Tyto alba foraging mainly in open-mosaic landscapes; Martínez & Zuberogoitia, 2004), information about small mammal assemblages may be obtained only for these contexts. Moreover, this type of sampling is hi- ghly opportunistic since it was indirectly obtained from the predators, therefore not following a standardized sampling protocol). However, excluding some weaknes- ses, there are many points of strength in this technique (Andrade et al., 2016): for example, once selected a roo- sting or nesting barn owl site, we can obtain representati- ve samples with a low research effort and, consequently, we may obtain a large set of data about prey species and their frequencies, richness, diversity, and other univariate metrics. Other methods (e.g. capture-mark-recapture by trapping) allow to obtain fewer representative samples (often with a high research effort) and diversity metrics 4 at community level are more difficult to achieve (Hei- sler et al., 2016). Data on small mammal communities, obtained from owl’ pellets, may be also useful to assess change in local owl diets (e.g. Catalisano & Massa, 1987; Love et al., 2000; Veselovský et al., 2017), composition, diversity and temporal trends in prey assemblages (e.g., Clark & Bunck, 1991; Bonvicino et al., 2003; Avenant, 2005; Celauro & Battisti, 2006; Meek et al., 2012; Ste- fke & Landler, 2020), multi-level trophic systems (e.g., Contoli, 1986; Contoli et al., 2002), ecological value and environmental quality at different spatial/temporal scales (e.g., Prete et al., 2012; Torre et al., 2015; Mancini et al., 2019), until to altitudinal (e.g. Milana et al., 2019), lati- tudinal (e.g. Leveau et al., 2006), biogeographical (e.g., Contoli et al., 1987; Battisti et al., 1997, 2019, 2020a) and genetic analyses (e.g. Taberlet & Fumagalli, 1996). Finally, also information about the presence or absence of specific, cryptic or threatened taxa can be obtained using this approach (e.g., Contoli, 1986; Contoli et al., 1992; McDonald et al., 2014; Biedma et al., 2019; Kiamos et al., 2019; Battisti et al., 2020b). Among the Strigiformes, the barn owl is widely used as source of data. Barn owls may be selective in habitat use, but are described by many as opportunistic predators that do not exhibit any food preferences; therefore, the species present in their pellets should provide a quite accu- rate representation of local prey abundance or accessibility (Taylor, 1994; Salvati et al., 2002; Heisler et al., 2016). Generally, the foraging habitat of barn owls is repre- sented by open landscapes, including grasslands, orchards, newly planted coniferous plantations and recently felled woodlands (Taylor, 1994). The unmanaged grassland ed- ges provided by agricultural crops, woodland ecotones, riverbanks, ditches and hedgerows also have value in mo- re intensively managed landscapes (Salvati et al., 2002). In the wild, barn owls are generally sedentary. Nests are abandoned only if the surrounding habitat becomes de- void of prey, due to changes in habitat quality and structu- re, or if the nests or roosts are altered (Taylor, 1994). The- refore, a good knowledge of the species’ feeding habitat and nesting/roosting sites allows to rapidly collect a large number of pellets containing a significant representation of their small-mammal preys (Contoli, 1975). In this work, by using barn owls’ pellets, we collected data about the small mammal guilds living in five sites located in an agroforestry landscape of Tyrrhenian central Italy (Maremma of Lazio). With the statistical analysis of these data, we aim to obtain an arrangement of small mammal frequency, richness, equitability and diversity, also in relation with the local landscape features and hete- rogeneity (habitat diversity). MAteRIAlS And MethodS Study area and sample collection We carried out a broad-scale sampling of barn owl pellets (summer 2018-summer 2019), in five collection sites distributed throughout the Tyrrhenian territory of the province of Viterbo, in habitats referable to the Maremma of Lazio (Fig. 1), the southernmost part of the Maremma, a region situated across the border between southern Tu- Fig. 1 - The study area. Circles and letters (A-E) show the five investigated sites. / Area di studio. I cerchi e le lettere (A-E) indicano i cinque siti studiati. VINCENZO FERRI, PAOLO CRESCIA, STEFANO CELLETTI, CHRISTIANA SOCCINI, CORRADO BATTISTI 5 scany and northern Lazio, in central Italy. The study area includes the Tyrrhenian coastal strip and the correspon- ding plain delimited to the north-west by the final course of the Chiarone River, which marks the border between the Maremma di Grosseto, in Tuscany, and Tuscia, in La- zio (Olmi & Zapparoli, 1992), and to the south, up to Cer- veteri, by the headland of Capo Linaro which represents the southernmost offshoot of the Tolfa Mountains (De Zu- liani, 2011). The area was described as a transitional zone from a Mediterranean to a Temperate bioclimate (Blasi, 1994) and has distinctive geological and vegetation featu- res (Marchetti et al., 2014; Cutini et al., 2010). Sampling sites Nest Site A. Roccaccia (42°21’0.50” N; 11°45’31.75” E; 149 m a.s.l.). The area is characterized by fodder crops, interspersed with coppices, composed of mixed Mediter- ranean oaks dominated by Turkey oaks Quercus cerris and downy oaks Quercus pubescens. Some sectors have been reforested with coniferous species (Pinus spp. and Cupressus spp.). Both cultivated areas and coppices are used in rotation or seasonally as a pasture for free-ranging cattle. Nest Site B. Riminino (42°27’10.57” N; 11°37’9.57” E; 90 m a.s.l.). The area is characterized by a limestone escarpment irregularly covered by Mediterranean arbore- al and shrub vegetation, overlooking a large grassy plain grazed by free-ranging cattle. The plain is crossed by the Fiora River, with hygrophilous vegetation growing along the banks. Above the escarpment there are plots bounded by hedges and crossed by ditches edged by hygrophilous vegetation, which are cultivated with fodder and cereals and successively used as pastures for sheep or as olive groves. Nest Site C. Ripagretta (42°14’50.82” N; 11°47’4.60” E; 122 m a.s.l.). The site is characterized by slightly el-The site is characterized by slightly el- evated limestone cliffs, partly covered by Mediterranean vegetation with prevalent arboreal and shrubby holm oak Quercus ilex and some downy oaks. The cliffs over- look a valley with vineyards, pastures and grasslands, with hedges and ecotonal habitats. In the above plateau, the westernmost sector is urbanized, while the rest is oc- cupied by the Necropolis of Tarquinia, where the pre- vailing herbaceous cover is periodically mown, and by cereal crops. Nest Site D. San Giorgio (42°11’4.00” N; 11°44’17.75” E; 6 m a.s.l.). Mosaic of croplands (mainly forage, cereal or horticultural crops), interspersed with uncultivated ar- eas and sheep pastures. There are isolated oaks Quercus spp., hedges, reservoirs and drainage channels with hy- grophilous and riparian vegetation, as well as a pine Pinus sp. and Italian stone pine P. pinea forest. Nest Site E. Montericcio (42°13’26.52” N; 11°51’24.96” E; 26 m a.s.l.) Not far from the Mignone River, the area is mainly characterized by herbaceous (cereals) and horticultural crops, which are used in suc- cession as sheep pastures. There are slopes with Mediter- ranean and sub-Mediterranean arboreal and shrubby veg- etation, hedges and tree-lined rows and drainage channels with associated hygrophilous vegetation. The landscape composition was assessed using Goo- gle Earth® (last accessed: October 2020) and landscape elements were analysed in detail within a 1 km radius area around each nest site, which approximates to the home range size (3 km2) of a barn owl during the breeding se- ason (Taylor, 1994; Horvàth et al., 2018). The five nest sites were described based on land-use types and the per- centages for the following categories calculated: 1) agri- cultural fields (annual and perennial crops); 2) extensive land use (grasslands, pastures, orchards, vineyards); 3) wet habitats (including river banks, streams, artificial la- kes, etc.); 4) forests (all forest habitats), and 5) urbanized areas (Tab. 1). Pellet analysis Pellets were collected from the nest sites between July 2018 and September 2019. Pellets were processed using the dry technique, with single pellets disassembled by hand and the prey items identified at the lowest possible taxonomic level. Osteological parts (mainly skulls and jaws) were ma- croscopically identified, while teeth and feathers were identified under a stereo microscope at 25× or 50× magni- fications. Analyses have been carried out in a private la- boratory. The identification was carried out at the species level, where possible, by comparing undigested remains with a reference collection (see Contoli, 1980) and fol- lowing Amori et al. (2008). Prey numbers were estimated as the minimum num- ber of individuals (MNI) obtained by counting the most Tab. 1 - Percentages of land use/cover and habitat diversity index (Hh) in the five studied sites. / Percentuali di uso/copertura del suolo e diversità ambientale (Hh) nei cinque siti studiati. Roccaccia (A) Riminino (B) Ripagretta (C) San Giorgio (D) Montericcio (E) Cropland 8.53 87.62 96.4 94.71 93.61 Orchards and vineyards 0.1 2.64 0.02 0 0.6 Wet habitats 0.77 8.03 0.45 2.3 1.35 Forests and wood mosaics 90.54 1.14 1.2 0.78 4.03 Urbanized areas 0.06 0.57 1.93 2.21 0.41 Hh index 0.349 0.495 0.191 0.26 0.303 SMALL MAMMALS IN A MEDITTERRANEAN AGROFORESTRY LANDSCAPE 6 common diagnostic osteological element of each species of small mammal in each pellet (McDowell & Medlin, 2009). Nomenclature followed Loy et al. (2019). Since the determination of the remnants of Apodemus to the spe- cies level is difficult for this genus in Italy, we used Apo- demus cfr. sylvaticus for the individuals assigned to this taxon. The number of pellets collected from each site varied considerably, but cumulative occurrence plots demonstra- ted that collections >10 pellets were adequate to assess the main species present in the diet (Bond et al., 2004). For each site, we obtained the number of species (S) and the normalized species richness (Margalef index) as Dm=(S-1)/ln(N-1) (Margalef, 1958), where N was the to- tal number of prey items. For each site we obtained the relative frequency of each species from the number of in- dividuals (fri, as number of ind. of the i-th species/total number of individuals). Finally, we obtained two univa- riate metrics of diversity: the Shannon-Wiener diversity index (Shannon & Weaver, 1949), as H’ = -Σ fri × lnfri and the equitability index, as e=H’/H’max where H’max = ln(S) (Pielou, 1966; details in Magurran, 2004). To assess the level of environmental heterogeneity (Hh), in each site we calculated an index of habitat diversity, following the analogous Shannon-Wiener formula. We compared H’ to Hh using the non-parametric Spe- arman rank correlation test (2 tail). From a species/site matrix, we performed both a Clu- ster analysis (Algorithm: Paired group - UPGMA, Eucli- dean similarity index) obtaining a dendrogram, in order to assess the similarity among communities, and a De- trended Correspondence Analysis (DCA) in order to test for the linkage among sites (i.e. assemblages) and species (Hill & Gauch, 1980). For statistical analyses we used the computer softwa- re PAST 4.01 (Hammer et al., 2001). The statistical tests were considered significant at the alpha level of 0.05 as standard in all analyses (Dytham, 2011). ReSultS Totally, we examined 373 pellets, identifying 687 rem- nants belonging to 11 terrestrial small mammal species: Apodemus cfr. sylvaticus (39%), Microtus savii (19.5%), Mus musculus (15.3%), Crocidura suaveolens (7.9%), Crocidura leucodon (7.4%) and Suncus etruscus (5.1%) being dominant (total frequency > 5%) on the whole (Tab. 2). Arvicola italicus is the only species of conservation concern at national scale (Near Threatened; Rondinini et al., 2013). We obtained also data on bats (Chiroptera: Pipistrellus sp., Eptesicus serotinus), and on other taxo- nomic groups (birds: Passer italiae, and undetermined beetles), not included in the analyses. The sites of Riminino (B), San Giorgio (D) and Mon- te Riccio (E) showed the highest Shannon-diversity and equitability indices, while Ripagretta (C) showed the lowest values. San Giorgio showed also the highest normalized species richness (Tab. 3). Species diversity H’ was not significantly correlated directly to habitat di- versity Hh (rs=0.743, p=0.20; Spearman rank correlation test, 2 tail). Dendrogram indicated two similarity groups: the less diversified A-C vs. other sites (correlation: 0.9851; Fig. 2). Detrended Correspondence Analysis (DCA; Eigenva- lue: axis 1: 0.1675, axis 2: 0.060; Fig. 3) displayed an analogous pattern, highlighting the general similarities and showing the faunal peculiarity of two sites (Riminino - B, the only site with Arvicola italicus, and San Giorgio - D, with the only record of Rattus norvegicus) and the low evenness and diversity of the sites A (Roccaccia) and C (Ripagretta) with a high concentration of dominance (frequency) of synanthropic species (Apodemus cfr. syl- vaticus and Mus musculus). Tab. 2 - Small mammal species, number of records (n) and relative frequency (fri) in the five studied sites. / Specie di piccoli mammiferi, numero di reperti (n) e frequenza relativa (fri) nei cinque siti studiati. Roccaccia (A) Riminino (B) Ripagretta (C) San Giorgio (D) Montericcio (E) Total Species n fri N fri n fri n fri N fri n fri Suncus etruscus (Savi, 1822) 9 0.054 3 0.014 4 0.040 3 0.083 16 0.094 35 0.051 Sorex samniticus Altobello, 1926 4 0.024 0 0 3 0.030 0 0 3 0.018 10 0.015 Crocidura suaveolens (Pallas, 1811) 9 0.054 26 0.123 6 0.059 4 0.111 9 0.053 54 0.079 Crocidura leucodon (Hermann, 1780) 11 0.065 16 0.076 6 0.059 0 0 18 0.105 51 0.074 Muscardinus avellanarius (Linnaeus, 1758) 1 0.006 0 0 1 0.010 0 0 4 0.023 6 0.009 Arvicola italicus Savi, 1839 0 0 6 0.028 0 0 0 0 0 0 6 0.009 Microtus savii (de Sélys Longchamps, 1838) 7 0.042 75 0.355 4 0.040 4 0.111 44 0.257 134 0.195 Apodemus cfr. sylvaticus (Linnaeus, 1758) 86 0.512 54 0.256 66 0.653 12 0.333 50 0.292 268 0.390 Mus domesticus Schwarz and Schwarz, 1943 35 0.208 25 0.118 10 0.099 9 0.250 26 0.152 105 0.153 Rattus rattus (Linnaeus, 1758) 6 0.036 6 0.028 1 0.010 3 0.083 1 0.006 17 0.025 Rattus norvegicus (Berkenhout, 1769) 0 0 0 0 0 0 1 0.028 0 0 1 0.001 Total 168 1 211 1 101 1 36 1 171 1 687 1 VINCENZO FERRI, PAOLO CRESCIA, STEFANO CELLETTI, CHRISTIANA SOCCINI, CORRADO BATTISTI 7 dIScuSSIon The study revealed small mammal communities com- posed by typical species of the agroforestry landscapes of central Italy (e.g. Contoli, 1986; Aloise et al., 1990; Capizzi & Luiselli, 1998; Battisti et al., 2019) that host different ecological guilds, as species strictly linked to croplands and mosaics (e.g. Microtus savii, Apodemus cfr. sylvaticus and Soricidae), to forests and ecotones (Mu- scardinus avellanarius, Sorex samniticus), to wet habitats (Arvicola italicus) and finally, synanthropic rodents (Mus domesticus, Rattus spp.). Except for site A (Roccaccia), all the other sites are characterized by landscape matrices with dominance of extensive croplands and other open habitats. These fea- tures explain the almost general predominance of species linked to these environments. However, minor changes among sites about land cover and its use can explain the different faunal composition. Muscardinus avellanarius and Sorex saminiticus (forest and ecotone species) have been recorded in the site with higher forest cover (Roc- caccia - A and, secondarily, Ripagretta - C and Monte- riccio - E). Moreover, in the site A forest-dominated the frequency of Microtus savii, a species linked to open agro-mosaic (Caroli et al., 2000), is lowest than other si- tes. The localized presence of wet habitats (near the site B - Riminino) explains the occurrence of Arvicola itali- cus and the dissimilarity from the sites A (Roccaccia) and C (Ripagretta). These last sites showed a high similarity. This pattern could be assigned to a low evenness of both of them that, although different in land use cover, showed communities with a very high concentration of dominan- ce in only two synanthropic species (Apodemus cfr. sylva- ticus and Mus musculus) and the lower frequencies of in Microtus savii. The limited number of sites and the different level of anthropization did not allow to obtain a significant corre- lation between habitat diversity index (a proxy of landsca- pe heterogeneity) and species diversity. However, exclu- ding the site D having a low prey sample, the sites with lowest habitat diversity also showed the lowest species diversity. The less environmental diversified site (Ripa- gretta - C) showed the lowest species diversity index and equitability. Land use composition and habitat diversity can ex- plain species frequency similarities among small mammal communities. In this regard, two sites (A and C) showed Fig. 2 - Dendrogram of similarity based on species frequency (algo- rithm: Paired group - UPGMA, Euclidean similarity index). / Dendro- gramma di similarità basato sulla frequenza di specie (algoritmo: gruppi appaiati - UPGMA, indice di similarità euclidea). Sites: / Siti: A) Roc- caccia. B) Riminino. C) Ripagretta. D) San Giorgio. E) Montericcio. Tab. 3 - Number of pellets (N pel), number of records (n), number of species (S), Shannon-Wiener diversity index (H’), equitability (e), normalized richness (Margalef index, Dm). / Numero di borre (N pel), numero di reperti (n), numero di specie (S), indice di diversità di Shannon- Wiener (H’), equiripartizione (e), ricchezza normalizzata (indice di Margalef, Dm). Site N pel n S H’ e Dm Roccaccia (A) 88 168 9 1.533 0.698 1.561 Riminino (B) 92 211 8 1.686 0.811 1.308 Ripagretta (C) 46 101 9 1.294 0.589 1.733 San Giorgio (D) 20 36 7 1.715 0.881 1.674 Montericcio (E) 127 171 9 1.798 0.818 1.556 Fig. 3 - Detrended Correspondence Analysis. / Analisi delle Cor- rispondenze ‘Detrended’ Sites: / Siti: A) Roccaccia; B) Riminino; C) Ripagretta; D) San Giorgio; E) Montericcio. Species: / Specie: Sunetr: Suncus etruscus; Sorsam: Sorex samniticus; Crosua: Crocidura suaveolens; Croleu: Crocidura leucodon; Musave: Muscardinus avel- lanarius; Arvita: Arvicola italicus; Micsav: Microtus savii; Aposyl: Apodemus cfr. sylvaticus; Musdom: Mus domesticus; Ratrat: Rattus rattus; Ratnor: Rattus norvegicus. SMALL MAMMALS IN A MEDITTERRANEAN AGROFORESTRY LANDSCAPE 8 a higher distance from the others. The first is included in- side a forest-dominated landscape and the second is the less environmentally diversified. This finding would cor- roborate what stated by Varuzza et al., (2001), which evi- denced differences in prey diversity between sites located in forest vs. cultivated sites. This pattern of similarity is confirmed by DCA analysis, which highlights the faunal distinctiveness of sites B and D, the low diversity and uni- formity of sites A and C, and suggests the existence of a relationship between species and sites. In this regard, axis 1 can represent the diversity/uniformity pattern. However, the same axis shows a low amount of overall informa- tion (eigenvalue about 17%) and the relative frequency of individual species may likely influence the observed pattern. Data from owl’s pellets provide a large amount of faunal, ecological and biogeographical information at site- and landscape-levels allowing in-depth analyses on diversity metrics of small mammal assemblages with a limited field effort. In this regard we would stimulate fur- ther research. Acknowledgements We thank Giovanni Amori, Longino Contoli and Spar- taco Gippoliti which gave useful hints on a first draft of the manuscript. Two anonymous reviewers and the Editor (Giorgio Chiozzi) provided valuable comments and sug- gestions at the same time improving the style and langua- ge of the manuscript. RefeRenceS Aloise G., Pelosi M. & Ronca M., 1990 − Small mammal communities of the “Monte Rufeno” Natural Reserve (Latium, Italy): data from Barn Owl Tyto alba pellets. / I popolamenti di micromammiferi della Riserva Na- turale “Monte Rufeno” (Lazio): dati da borre di barba- gianni Tyto alba. Hystrix. The Italian Journal of Mam- malogy, 2 (1): 23-34. Amori G., Contoli L., Nappi A. (eds.), 2008 − Mammalia II. Erinaceomorpha, Soricomorpha, Lagomorpha, Ro- dentia. Fauna d’Italia. Edizioni Calderini - Il Sole 24 ORE Business Media, Milano, XLIV. Andrade A., de Menezes J. F. S. & Monjeau A., 2016 − Are owl pellets good estimators of prey abundance? Journal of King Saud University-Science, 28 (3): 239- 244. Avenant N. L., 2005 − Barn owl pellets: a useful tool for monitoring small mammal communities. Belgian Journal of Zoology, 135 (suppl.): 39-43. Balestrieri A., Gazzola A., Formenton G. & Canova L., 2019 − Long-term impact of agricultural practices on the diversity of small mammal communities: a case study based on owl pellets. Environmental Monitoring and Assessment, 191 (725). Battisti C., Cignini B. & Contoli L., 1997 − Geographical peninsular effects on the trophic system “Tyto alba- micromammals” in Salento (Italy). Hystrix, the Italian Journal of Mammalogy, 9 (1-2): 13-22. Battisti C., Dodaro G., Di Bagno E. & Amori G., 2019 − Reviewing an eco-biogeographic question at regional scale: the unexpected absence of a ubiquitous mammal species (Microtus savii, Rodentia) in coastal Southern Tuscany (central Italy). Rendiconti Lincei. Scienze Fi- siche e Naturali, 30: 715-722. Battisti C., Marta S., Agnelli P., Luiselli L., Stoch F. & Amori G., 2020a − Peninsular effect on species rich- ness in Italian small mammals and bats. Mammalia, 85 (3): 248-255. Battisti C., Dodaro G., Di Bagno E. & Amori G., 2020b − Small mammal assemblages in land-reclaimed areas: do historical soil use changes and recent anthropisa- tion affect their dominance structure? Ethology Ecol- ogy & Evolution, 32 (3): 282-288. Biedma L., Román J., Godoy J. A. & Calzada J., 2019 − Using owl pellets to infer habitat associations and clar- ify the regional distribution of a cryptic shrew. Journal of Zoology, 308: 139-148. Blasi C., 1994 − Fitoclimatologia del Lazio. Fitosociolo- gia, 27: 151-175. Bond G., Burnside N. G., Metcalfe D. J. & Scott D. M., 2004 − The effect of land-use and landscape structure on Barn owl (Tyto alba) breeding success in Southern England, U.K. Landscape Ecology, 20: 555-566. Bonvicino C. R. & Bezerra A. M., 2003 − Use of regurgi- tated pellets of Barn owl (Tyto alba) for inventorying small mammals in the Cerrado of Central Brazil. Stu- dies on Neotropical Fauna and Environment, 38 (1): 1-5. Brunelli M., Sarrocco S., Corbi F., Sorace A., Boano A., De Felici S., Guerrieri G., Meschini A. & Roma S., 2011 − Nuovo Atlante degli Uccelli Nidificanti nel La- zio. Edizioni ARP (Agenzia Regionale Parchi), Roma. Capizzi D. & Luiselli L., 1998 − A comparative study of the variability of owl diets in three localities of central Italy. Revue d’écologie, 53: 367-385. Caroli L., Capizzi D. & Luiselli L., 2000 − Reproduc- tive strategies and life-history traits of the Savi’s pine vole, Microtus savii. Zoological Science, 17 (2): 209- 216. Catalisano A. & Massa B., 1987 − Considerations on the structure of the diet of the Barn owl (Tyto alba) in Sic- ily (Italy). Italian Journal of Zoology, 54: 69-73. Celauro D. & Battisti C., 2006 − Small mammal commu- nities in a suburban agroforest landscape (Rome, Cen- tral Italy): faunal and ecological considerations using Tyto alba pellets. Aldrovandia, 2: 55-60. Clark Jr. D. R. & Bunck C. M., 1991 − Trends in North American small mammals found in common barn-owl (Tyto alba) dietary studies. Canadian Journal of Zool- ogy, 69: 3093-3102. Contoli L., 1975 − Micro-mammals and environment in central Italy: Data from Tyto alba (Scop.) pellets. Ital- ian Journal of Zoology, 42: 223-229. Contoli L., 1980 − Borre di Strigiforni e ricerca teriologi- ca in Italia. Natura e Montagna, 3: 73-94. Contoli L., 1986 − Sistemi trofici e corologia: dati su Sori- cidae, Talpidae ed Arvicolidae d’Italia predati da Tyto alba (Scopoli 1769). Hystrix, 1 (2): 95-118. VINCENZO FERRI, PAOLO CRESCIA, STEFANO CELLETTI, CHRISTIANA SOCCINI, CORRADO BATTISTI 9 Contoli L. & Sammuri G., 1978 − Predation on small mammals by tawny owl and comparison with barn owl in the Farma valley (central Italy). Italian Journal of Zoology, 45: 323-335. Contoli L., Salucci M. P. & Vigna Taglianti A., 1987 − Per una biogeografia dei sistemi trofici: il sistema “mam- miferi terragnoli-Tyto alba” nell’Italia peninsulare e nelle isole maggiori. Biogeographia. The Journal of Integrative Biogeography, 11: 211-231. Contoli L., Aloise G., Amori G. & Ranazzi L., 1992 − Sull’uso dei predatori nel censimento dei micromam- miferi terragnoli. Supplemento alle Ricerche di Biolo- gia della Selvaggina, 16: 449-464. Contoli L., Testi A., Tittarelli L. & Benedetti P., 2002 − Are animal trophic systems as reliable an expression of climate as are plant communities? Preliminary evi- dence from the tyrrhenian belt in Italy. Ecologia medi- terranea, 28: 75-92. Cutini M., Cancellieri L., Cioffi M. T. & Licursi C., 2010 − Phytosociology and phytogeography of fragmented Alnus glutinosa forests in a Tyrrhenian district (Cen- tral Italy). Ecologia Meditrranea, 36 (2): 55-73. De Zuliani E., 2011 − Diacrhronic analysis of the Marem- ma laziale (Latium) for the conservation of the natural and cultural landscapes. Università degli Studi Roma Tre. Ph. Doct. Thesys, available on: Dytham C., 2011 − Choosing and using statistics: a biolo- gist’s guide. John Wiley & Sons. Farina A., 2001 − Ecologia del Paesaggio. Principi, meto- di e applicazioni. UTET Libreria, Torino. Hammer Ø., Harper D. A. T. & Ryan P. D., 2001 − Past: Paleontological Statistics Software Package for Edu- cation and Data Analysis. Palaeontologia Electronica, 4 (1): 1-9. Heisler L. M., Somers C. M. & Poulin R. G., 2016 − Owl pellets: a more effective alternative to conventional trapping for broad‐scale studies of small mammal communities. Methods in Ecology and Evolution, 7: 96-103. Hill M. O. & Gauch H. G., 1980 − Detrended correspond- ence analysis, an improved ordination technique. Veg- etation, 42: 47-58. Horváth A., Morvai A. & Horváth G. F., 2018 − Food- niche pattern of the Barn Owl (Tyto alba) in intensive- ly cultivated agricultural landscape. Ornis Hungarica, 26: 27-40. Kiamos N., Lymberakis P., Rallis G. & Poulakakis N., 2019 − Barn owl (Tyto alba) prey in Evros (Greece) and the discovery of a new mammal for the Greek fau- na. Journal of Natural History, 53: 1691-1705. Leveau L. M., Teta P. V., Bogdaschewsky R. & Pardiñas U. F. J., 2006 − Feeding habits of the Barn Owl (Tyto alba) along a longitudinal-latitudinal gradient in cen- tral Argentina. Ornitologia Neotropical, 17: 353-362. Loy A., Aloise G., Ancillotto L., Angelici F. M., Bertolino S., Capizzi D., Castiglia R., Colangelo P., Contoli L., Cozzi B., Fontaneto D., Lapini L., Maio N., Monaco A., Mori E., Nappi A., Podestà M., Russo D., Sarà M., Scandura M., Amori G., 2019 − Mammals of Italy: an annotated checklist. Hystrix, 30: 87-106. Love R. A., Webon C., Glue D. E., Harris S. & Harris S., 2000 − Changes in the food of British Barn Owls (Tyto alba) between 1974 and 1997. Mammal review, 30: 107-129. Magurran A., 2004 − Measuring biological diversity. Blackwell Publishing, Malden, MA. Mancini M. C., Roth P. R. O., Brennand P. G., Aguilar J. M. R. E. & Rocha P. A., 2019 − Tyto furcata (Tytoni- dae: Strigiformes) pellets: tools to access the richness of small mammals of a poorly known Caatinga area in northeast Brazil. Mammalia, 83: 390-398. Marchetti M., Sapia V., Garello A., De Rita D. & Venuti A., 2014 − Geology and geophysics at the archeologi- cal park of Vulci (central Italy). Annals of Geophysics, 57 (1): G0188. Margalef R., 1958 − Information theory in ecology. Gen- eral Systems, 3: 36-71. Martínez J. A. & Zuberogoitia I., 2004 − Habitat prefer- ences and causes of population decline for Barn Owls Tyto alba: a multi-scale approach. Ardeola, 51: 303- 317. McDonald K., Burnett S. & Robinson W., 2014 − Util- ity of owl pellets for monitoring threatened mammal communities: an Australian case study. Wildlife Re- search, 40: 685-697. McDowell M. C. & Medlin G. C., 2009 − Using the diet of the barn owl (Tyto alba) as an indicator of small vertebrate abundance in the Channel Country, south- western Queensland. Australian Mammalogy, 31: 75- 80. Meek W. R., Burman P. J., Sparks T. H., Nowakowski M. & Burman N. J., 2012 − The use of Barn Owl Tyto alba pellets to assess population change in small mam- mals. Bird Study, 59: 166-174. Milana G., Battisti C., Luiselli L. & Amori G., 2019 − Altitudinal variation of community metrics in Italian small mammal assemblages as revealed by Barn Owl (Tyto alba) pellets. Zoologischer Anzeiger, 281: 11-15. Olmi M. & Zapparoli M., 1992 − Ambiente nella Tuscia laziale. Aree protette e di interesse naturalistico della provincia di Viterbo. Università degli Studi della Tus- cia. Union Printing Edizioni. Pielou E. C., 1966 − The measurement of diversity in dif- ferent types of biological collections. Journal of Theo- retical Biology, 13: 131-144. Prete S., Battisti C., Marini F. & Ciucci P., 2012 − Ap- plying abundance/biomass comparisons on a small mammal assemblage from Barn owl (Tyto alba) pel- lets (Mount Soratte, central Italy): a cautionary note. Rendiconti Lincei, 23 (4): 349-354. Regione Lazio, 1990 − Technical Regional Map (scale 1:10,000). Regione Lazio, Roma. Reidsma P., Tekelenburg T., van den Berg M. & Alkemade R., 2006 − Impacts of land-use change on biodiversity: an assessment of agricultural biodiversity in the Euro- pean Union. Agriculture Ecosystems & Environment, 114: 86-102. Rondinini C., Battistoni A., Peronace V. & Teofili C. (eds.), 2013 − Lista Rossa IUCN dei Vertebrati Italia- ni. Comitato Italiano IUCN e Ministero dell’Ambiente e della Tutela del Territorio e del Mare, Roma. SMALL MAMMALS IN A MEDITTERRANEAN AGROFORESTRY LANDSCAPE 10 Salvati L., Ranazzi L. & Manganaro A., 2002 − Habitat preferences, breeding success and diet of barn owls in Rome: urban versus rural territories. Journal of Raptor Research, 36: 224-228. Shannon C. E. & Weaver W., 1949 − The mathematical theory of communication. University of Illinois Press, Urbana. Stefke K. & Landler L., 2020 − Long-term monitoring of rodent and shrew communities in a biodiversity hot- spot in Austria using Barn owl (Tyto alba) pellets. Acta Oecologica, 109: 103660. Taberlet P. & Fumagalli L., 1996 − Owl pellets as a source of DNA for genetic studies of small mammals. Mo- lecular Ecology, 5: 301-305. Taylor I. R., 1994 − Barn owls. Predator-prey Relation- ships and Conservation. Cambridge University Press, Cambridge, UK. Tome R. & Valkama J., 2001 − Seasonal variation in the abundance and habitat use of Barn Owls (Tyto alba) on lowland farmland. Ornis Fennica, 78: 109-118. Torre I., Gracia-Quintas L., Arrizabalaga A., Baucells J. & Díaz M., 2015 − Are recent changes in the terres- trial small mammal communities related to land use change? A test using pellet analyses. Ecological Re- search, 30: 813-819. Varuzza P., Capizzi D., Santini L. & Apollonio M., 2001 − Barn Owl Tyto alba predation on small mammals in relation to the Mediterranean environment (Pisa Prov- ince, Italy). Acta Ornithologica, 36 (2): 153-160. Veselovský T., Bacsa K. & Tulis F., 2017 − Barn Owl (Ty- to alba) diet composition on intensively used agricul- tural land in the Danube Lowland. Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, 65: 225-233. Yom-Tov Y. & Wool D., 1997 − Do the contents of Barn Owl pellets accurately represent the proportion of prey species in the field? The Condor, 99 (4): 972-976. VINCENZO FERRI, PAOLO CRESCIA, STEFANO CELLETTI, CHRISTIANA SOCCINI, CORRADO BATTISTI