Increased brown bear predation on sika deer fawns following a deer population irruption in eastern Hokkaido, Japan

By the 1970s, brown bears (Ursus arctos) in Hokkaido, northern Japan, were opportunistic omnivores that mainly depended on plant materials. Because the sika deer (Cervus nippon) population irrupted in eastern Hokkaido in the 1990s, we expected that brown bears might prey on sika deer fawns. First, we developed a simple and cost-effective method of monitoring possible bear predation on deer fawns by analyzing the widths of deer hairs remained in bear scats. Based on hair thickness standards, we distinguished the brown bear consumption of deer fawns from adults by analyzing bear scats (n?=?108) collected during the deer birthing season (late May?Clate July) in 1999?C2008. To evaluate the importance of fawns to bears, we compared the occurrence of fawn and adult deer hairs in bear scats among three periods (I, 1999?C2000; II, 2003?C2005; III, 2006?C2008) in eastern Hokkaido. The occurrence of fawn hairs in bear scats increased from 12.5 to 27.3?% in volume and from 6.3 to 33.6?% in frequency from period I to period III, whereas adult hairs in scats decreased from 42.8 to 26.1?% in volume and from 34.4 to 22.7?% in frequency during the same time. These data suggest that bears increasingly preyed on deer fawns after the deer population irruption and decreasingly used adult carcasses because of the enforcement of deer carcass treatment by the Hokkaido government.     

Feral cats on Stewart Island; their foods,and their effects on kakapo

Abstract

The foods of feral house cats (Felis catus) on Stewart Island were determined by examining 229 scats collected during surveys of the distribution and numbers of kakapo (Strigops habroptilus), an endangered ground-parrot species. Rats occurred in 93% of the scats, birds in 44. 1%, wetas (large orthopterans) in 26.2%, and lizards in 24.0%. Twelve (70.6%) of the 17 species of birds were native. Kakapo remains were found in 6 (5.1%) of the 118 scats collected from areas where kakapo have been recorded.     

Predation of insects by feral cats (<Emphasis Type="Italic">Felis silvestris catus</Emphasis> L., 1758) on an oceanic island (La Palma,Canary Island)

Predation of insects by feral cats (Felis silvestris catus) on a heterogeneous oceanic island (La Palma, Canary Islands) was studied. A total of 127 invertebrates were identified in the analysis of 500 scats (100 from each habitat of the Island). Invertebrates appear in 18.00% of the scats, representing an insignificant percentage of the total consumed biomass by feral cats on La Palma Island (0.05%). Insects were the most common invertebrate prey both in percentage of occurrence (90.6%) and invertebrate biomass (93.53%), with a total of 115 prey items. Orthoptera, Lepidoptera and Coleoptera were the main prey groups. Among the five main habitats present in La Palma Island, the temperate forest shows the lowest consumption of invertebrates, although insect consumption did not show statistical differences. However Orthoptera and Lepidoptera were more frequently preyed on in the pine forest and in the xerophytic shrub, respectively. Moreover, applying the Simplified Morisita index, a different insect composition of the diet was observed among habitats. Although, none of insects predated by feral cats are threatened, the identification of invertebrate component of the feral cats’ diet is an important tool for the correct understanding of predation significance and to prevent damage to endangered insect species.     

Variation in the diet of red foxes on Scottish moorland in relation to prey abundance

The diet of red fox Vulpes vulpes was investigated through analysis of 340 scats collected during 1992-1996 from moorland in south-west Scotland. Rodents, game-birds, lagomorphs, carrion and insectivores were the most frequently occurring food types. Fox diet and prey abundance were compared between heather dominant and grass dominant habitat types within the study area. Rodents were the most frequently occurring food type in each habitat and occurred in 63% of seats overall. Rodents occurred more often in scats from grass dominant sites while gamebirds and lagomorphs were more frequent in scats from heather dominant sites. The occurrence of rodents in winter fox scats increased with rodent abundance. In contrast, the occurrence of gamebirds in winter fox scats was unrelated to gamebird abundance but negatively related to rodent abundance. It appeared that foxes switched to gamebirds in years, or habitats, where rodents were uncommon.     

Shifts in fisher (Pekania pennanti) diet in response to climate-induced tree mortality in California assessed with DNA metabarcoding

A recent climate-induced tree mortality event in California, USA has led to dramatic landscape-level changes in the southern Sierra Nevada. Wide-spread conifer mortality was documented in habitat occupied by fisher (Pekania pennanti), a mature-forest associated species of conservation concern in this region. We analyzed fisher scats collected on the Sierra National Forest from the pre-tree-mortality period (PreTM, 2011 – 2013) and post-tree-mortality period (PostTM, 2017 – 2018). We used DNA metabarcoding to successfully identify taxa and summarized diet composition for 109 PreTM and 102 PostTM fisher scats. We observed 48 different diet items (33 assigned to species and 15 to genus). Mammals, birds, and plants of the Ribes genus (gooseberries and currents) comprised the highest proportions of diet items, although scats also contained DNA from reptiles, insects, arachnids, snails, and fungi. The frequency of occurrence of mammalian prey items was lower in PostTM (49.0%) versus PreTM scats (81.7%) with a reduction in the occurrence of two tree squirrels (Douglas squirrel and Humboldt’s flying squirrel). A higher proportion of scats collected PostTM (46.1%) contained DNA from Ribes spp. versus scats collected PreTM (19.3%). Our data reveal potential cascading effects of climate-induced tree mortality on fisher diet in the southern Sierra Nevada. Flexibility in fisher diet, however, may allow resilience to ecological change though future studies should consider the behavioral, energetic, demographic or fitness consequences from a shift away from medium-sized mammalian prey to plants.     

Feeding habits of Geoffroy's cat (Leopardus geoffroyi) in southern Brazil

The present study was carried out from 2001 to 2005, with the objective of analyzing the diet of Leopardus geoffroyi in extreme southern Brazil, through analyses of stomach contents and scats. The importance of each prey type found in the scats (n=66) was determined from the frequency of occurrence and percentage of occurrence. In the stomachs (n=9), the importance of each prey was determined using Pianka's index of relative importance (IRI). The food spectrum of L. geoffroyi included mammals, birds, serpents, amphibians and insects. Mammals were the most abundant items, present in 95.5% of the scats and representing 74.4% of the total prey, reaching an IRI of 13296.3 in the stomachs. The principal prey types found in the stomachs and scats were small rodents (Cavia spp., Oligoryzomys spp., Necromys spp. and Holochilus brasiliensis) and large-sized rodents (Myocastor coypus), of terrestrial, arboreal or semi-aquatic habit. Probably, the high percentage of these prey items in the diet is related to their availability and abundance. The index of niche breadth was low in both the stomach and scat analyses (respectively, B_sta=0.18 and 0.17), demonstrating the high degree of specialization of these cats.     

Foods of feral house cats (Felis catus L.) in forest of the Orongorongo Valley,Wellington

Abstract

The foods of feral house cats in forest in the Orongorongo Valley, Wellington, were studied over 3 years and related to the availability of prey. Some cats were trapped, tagged, and released, and could be identified individually by coat colour and pattern. The number of cats, estimated from live-trapping and sightings, was stable during the study. Examination of 677 scats revealed that mammals (rat, rabbit, opossum, mouse, and stoat, in descending order of importance) formed the bulk of the diet by weight. Remains of birds occurred in 12% of scats, but birds were estimated to form only 4.5% by weight of the diet. Insect fragments were present in many scats; wetas (Orthoptera), cicadas (Hemiptera), and beetles (Colcoptera) were important seasonally. Although eaten in large numbers, they contributed very little by weight to the diet. Populations of rats, rabbits, and opossums were fairly stable during the study; mice were abundant for most of the first 18 months, but were scarce in the last year. The literature on the food habits of feral house cats is reviewed; it emphasises that cats are primarily predators of small mammals (rodents and lagomorphs). Predation by feral cats can be important in holding rat and rabbit populations at low densities and in reducing seasonal fluctuations in their numbers. Cats can also exert heavy predation pressure on low-density mouse populations. Although the cats now eat few birds, they may have been responsible for reducing the numbers of some forest birds in the past.     

The diet of feral cats at New Island, Falkland Islands, and impact on breeding seabirds

We studied the diet of feral cats (Felis catus) on New Island, Falkland Islands, through the analysis of 373 scats collected during the austral summers of 2004/2005 and 2005/2006. The most frequent prey were three introduced mammals (house mice Mus musculus, ship rats Rattus rattus and rabbits Sylvilagus sp.) and the thin-billed prion Pachyptila belcheri (each season present on ca. 21% of the analysed scats). These represent the first systematic data on feral cat diet for the Falklands. A simple bioenergetics model suggests that cats could be eating in the region of 1,500–11,000 prions per season, representing <1% of the local adult and subadult population. Predation on other seabirds nesting on New Island (several penguin species, albatrosses and cormorants) was unimportant, with the possible exception of white-chinned petrels Procellaria aequinoctialis, which nest locally in very small numbers. For each prion eaten, cats were estimated to have killed 1.1–1.9 ship rats during the summer season, and probably more in autumn and winter. Knowing that ship rats are prion predators, it is conceivable that, on the whole, cats are having a positive impact on the prion population, a scenario predicted by general theoretical models. Thus, considering the available information, we would not recommend the implementation of any eradication programme on New Island that would target cats in isolation. Nevertheless, it would be prudent to consider some local action targeting cats and rats around the small New Island white-chinned petrel colony.     

Black-backed jackal diet at Mokolodi Nature Reserve, Botswana

We examined the feeding habits of black‐backed jackals at Mokolodi Nature Reserve, Botswana, by analysing 237 scats collected between November 1995 and February 1997. Jackal dietary habits reflected the availability of a wide variety of food items and the differential vulnerability of prey. Potential animal and plant food available to jackals varies throughout the year because of its seasonal character. Seasonality of prey occurrence in scats was pronounced for small mammals, miscellaneous fruits and invertebrates. Across all seasons, mammals were the most common food resource (32.4%, n = 168), followed by anthropogenic items (14.8%), fruits (12.9%), invertebrates (10.8%), birds (8.5%), unidentified items (3.5%) and reptiles (1.4%). The presence of domestic mammals and poultry remains in scats reveals their importance in the diet of jackals and the tendency of jackals to frequent human settlements in search of food. Some ecological implications of jackal dietary habits are also explored.     

Mammalian Diet and Broad Hunting Strategy of the Dingo (Canis familiaris dingo) in the Wet Tropical Rain Forests of Northeastern Australia1

The diet of dingoes (Canis familiaris dingo) in the Australian Wet Tropics was examined by analyzing 383 dingo scats collected throughout the region for the presence of mammal prey remains. The scats yielded 29 native and 4 introduced mammal prey species from 14 families. The most important species in terms of percentage occurrence in the scats were Melomys cervinipes (22.2%), hoodon macrourus (17.0%), Perameles nasuta (12.5%), and Thylogale stigmatica (12.5%). The most important families were Muridae (37.1%), Peramelidae (29.5%), and Macropodidae (25.8%). Examination of small‐scale habitat preferences revealed species that preferentially use the forest edge ranked significantly higher in the diet than those that do not, and species that are terrestrial ranked higher in the diet than those that are arboreal. Relative abundance was also a significant factor in the ranked dietary occurrence of each species, with abundant species ranked significantly higher than those that are less abundant. These results suggest that dingoes in the Australian Wet Tropics are opportunistic predators of a wide variety of mammal species, with abundant terrestrial and forest edge‐dwelling taxa the most susceptible to predation.     

Food habits of the snow leopard Panthera uncia (Schreber, 1775) in Baltistan, Northern Pakistan

The snow leopard (Panthera uncia) inhabits the high, remote mountains of Pakistan from where very little information is available on prey use of this species. Our study describes the food habits of the snow leopard in the Himalayas and Karakoram mountain ranges in Baltistan, Pakistan. Ninety-five putrid snow leopard scats were collected from four sites in Baltistan. Of these, 49 scats were genetically confirmed to have originated from snow leopards. The consumed prey was identified on the basis of morphological characteristics of hairs recovered from the scats. It was found that most of the biomass consumed (70%) was due to domestic livestock viz. sheep (23%), goat (16%), cattle (10%), yak (7%), and cattle?Cyak hybrids (14%). Only 30% of the biomass was due to wild species, namely Siberian ibex (21%), markhor (7%), and birds (2%). Heavy predation on domestic livestock appeared to be the likely cause of conflict with the local inhabitants. Conservation initiatives should focus on mitigating this conflict by minimizing livestock losses.     

Food habits of the ferret (Mustela putorius furo L.) at Pukepuke Lagoon,New Zealand

The food habits of 44 tagged ferrets at a wildlife management reserve in the Manawatu dune country were examined from analysis of 333 scats, collected over a period of 34 months. Of the 203 scats containing prey, mammals occurred in 54.7%, birds and eggs in 33.5%, frogs in 17.2%, and eels in 13.3%. The 21 insects occurring in 10.3 % of the scats may have been taken as prey, but their importance in the diet is probably minimal. There was significant monthly variation in the occurrence of all prey groups, related to changes in availability or vulnerability of the prey populations. Female ferrets apparently ate the smaller prey items more often than males, but the differences were significant only for mice. No assessment of the effects ferrets have as predators on any of the prey populations is possible from this study.     

The Diet of Feral Cats (

Feral cats became established on Raoul Island some time between 1836 and 1872; the prey available to them included a great variety of nesting seabirds, few of which are present now, landbirds and kiore (Rattus exulans). Norway rats reached the island in 1921, providing additional prey for cats, but also another potential predator of seabirds. The diet of cats is described from guts and scats collected between 1972 and 1980. Rats are the main food, with land birds second in importance, and seabirds are now a minor item. More than 90% of the rats eaten by cats are kiore although more Norway rats than kiore are trapped. Eradicating cats from Raoul Island is feasible but because Norway rats too are important predators of birds on islands, it is likely that eradicating cats without also eradicating Norway rats will do little to restore the diversity of bird species on Raoul Island, although the densities of a few species now present might be increased.     

Trophic habits of feral cats in the high mountain shrublands of the Macaronesian islands (NW Africa,Atlantic Ocean)

Feral cats Felis catus Linnaeus, 1758 have contributed to the extinction of numerous native species on islands, which are clearly sources of global biodiversity. We studied the diet of this introduced predator in the Madeira and Cape Verde archipelagos, which harbour important colonies of endangered seabirds in the high mountain habitats, and compared the results with those obtained in the same habitat in the Canary Islands, Macaronesian archipelago. On Madeira, 461 prey were identified from 143 scat groups. Mammals, overall mice, constituted the basic diet appearing in 95% of cat scats. On Fogo (Cape Verde), 657 prey items were obtained from 145 scats, and mammals were also the most important prey, reaching a frequency of occurrence of 88%. Although introduced mammals were the main prey category on all Macaronesian islands, we observed variation in feral cat diet among these islands. Birds were more frequently consumed on Madeira, lizards on Tenerife (Canaries) and invertebrates on Fogo. No specific differences were observed in relation to La Palma. We suggest that the diet composition on these islands varies according to the respective availability of the different prey types.     

Free-Ranging Farm Cats: Home Range Size and Predation on a Livestock Unit In Northwest Georgia

This study’s objective was to determine seasonal and diurnal vs. nocturnal home range size, as well as predation for free-ranging farm cats at a livestock unit in Northwest Georgia. Seven adult cats were tracked with attached GPS units for up to two weeks for one spring and two summer seasons from May 2010 through August 2011. Three and five cats were tracked for up to two weeks during the fall and winter seasons, respectively. Feline scat was collected during this entire period. Cats were fed a commercial cat food daily. There was no seasonal effect (P > 0.05) on overall (95% KDE and 90% KDE) or core home range size (50% KDE). Male cats tended (P = 0.08) to have larger diurnal and nocturnal core home ranges (1.09 ha) compared to female cats (0.64 ha). Reproductively intact cats (n = 2) had larger (P < 0.0001) diurnal and nocturnal home ranges as compared to altered cats. Feline scat processing separated scat into prey parts, and of the 210 feline scats collected during the study, 75.24% contained hair. Of these 158 scat samples, 86 contained non-cat hair and 72 contained only cat hair. Other prey components included fragments of bone in 21.43% of scat and teeth in 12.86% of scat. Teeth were used to identify mammalian prey hunted by these cats, of which the Hispid cotton rat (Sigmodon hispidus) was the primary rodent. Other targeted mammals were Peromyscus sp., Sylvilagus sp. and Microtus sp. Invertebrates and birds were less important as prey, but all mammalian prey identified in this study consisted of native animals. While the free-ranging farm cats in this study did not adjust their home range seasonally, sex and reproductive status did increase diurnal and nocturnal home range size. Ultimately, larger home ranges of free-ranging cats could negatively impact native wildlife.     

Feeling the pressure at home: Predator activity at the burrow entrance of an endangered arid‐zone skink

Habitat modification and invasive species are among the most important contemporary drivers of biodiversity loss. These two threatening processes are often studied independently and few studies have focused on how they interact to influence species declines. Here we assess the predation pressure placed on the threatened great desert skink (Liopholis kintorei) and how this interacts with fire‐induced habitat modifications. We collected daily track data of potential predators for 1 month at 30 great desert skink burrow‐systems where vegetation cover varied significantly after experimental burns. We used these data to evaluate potential predation pressure at the burrow‐system and assess whether fire influenced predator pressure. We supplemented this analysis by documenting predation via the inspection of large mammalian predator scats collected from great desert skink habitat. The level of feral cat activity at a burrow‐system entrance was significantly higher than that of any other potential predator, however fire had no effect on the visitation rates of feral cats, dingoes or large snakes to great desert skink burrow‐systems. The remains of great desert skink were found significantly more frequently in feral cat scats, compared to fox and dingo scats. We provide the first direct evidence that feral cats are a significant predator for great desert skink, thus supporting the hypothesis that feral cat predation is a key threatening process. Feral cat activity was not influenced by small‐scale experimental burns, however, this does not preclude an effect of larger scale fires and we recommend further research exploring this possible interaction.     

Food habits of the pale fox (Vulpes pallida) in Niger

The pale fox (Vulpes pallida) is a small, little known African carnivore that is patchily distributed throughout the Sahel. We studied the food habits of pale foxes in the Termit and Tin Toumma National Nature Reserve in south‐eastern Niger by examining the frequency of occurrence and proportions of prey remains in scats (n = 398). Arthropods, primarily Coleoptera, Orthoptera and Scorpiones, were present in 91.8% of scats. Mammalian remains, primarily Gerbillus spp., were found in 5.6% of scats. Avian, squamate and plant material were rarely present. There was little evidence of seasonal variation in the frequency of occurrence or proportions of prey in the diet, confirming that pale foxes are primarily insectivorous.     

Non-invasive monitoring of red fox exposure to rodenticides from scats

Exposure of wildlife to anticoagulant rodenticides is mainly assessed by analysing residues in the tissues, notably liver, of dead animals. Recent finding suggested that the analysis of active ingredients in mammal scats sampled in the field could be used as a non-invasive method to monitor non-lethal exposure in populations. Here, we measure experimentally the persistence of 6 anticoagulant rodenticides in fox scats when placed under natural conditions. Six foxes were fed with voles dosed with brodifacoum, bromadiolone, chlorophacinone, warfarin, difenacoum and difethialone in controlled conditions and their faeces were collected. Then, the scats were placed outside, thus exposed to weathering, and sampled up to four months later to measure the concentrations of the 6 rodenticides. We showed that both the concentrations and the occurrence of residues in the scats decreased rapidly for all these pesticides. Based on concentrations, the degradation half-lives ranged from 5.26 days for chlorophacinone to 7.98 days for bromadiolone. Furthermore, the probability of sampling a scat containing detectable residues decreased by 10% after 7d, 2d, 10d, 5d, 3d and 10d for warfarin, chlorophacinone, bromadiolone, brodifacoum, difenacoum and difethialone respectively. Thus, in terms of using residues in scats to monitor fox exposure to rodenticides, we recommend first, to clear the studied areas of old faeces and then, sample scats after a short period, ideally <5 days.     

Diet composition of wolves<Emphasis Type="Italic">Canis lupus</Emphasis> in the northeastern Qinghai-Tibet Plateau,China

From August 1998 to August 2001, 119 wolf scats were collected from the desert in a pastoral region in northeastern Qinghai-Tibet Plateau, China. The study area is the last habitat for the critically endangered Przewalski’s gazelleProcapra przewalskii. Wolf predation was hypothesized as a cause of the endangerment of the Przewalski’s gazelle. The diet of wolf during the plant green period (June-September) and the plant withering period (October-May) were determined using three scat-analysis methods: frequency of occurrence, mass in scats and the ingested biomass obtained with the linear regression models of Weaver (1993). Limited to mammalian prey, total agreement was found between the dry weight and biomass methods, but less so between the frequency of occurrence data and other methods. Hare, yak, and small rodents were the important prey species of the wolves during the plant green period, each accounting for 33, 27, and 20%. Yak, sheep and hare were the important prey species during the plant withering period, each accounting for 53, 25, and 17%. Other food types were badger, Przewalski’s gazelle, birds, reptiles, invertebrates and plants. The presence of the livestock remains in the wolf’s scats may imply scavenging behavior by the wolves, because few cases of missing livestock were reported during the study. No notable seasonal difference in the diet composition of the wolves was found. The food niche of wolf during the plant green period (0.55 ± 0.02) was similar to that during the plant withering period (0.50 ± 0.02).     

Golden jackal (Canis aureus L.) diet in Southern Greece

The diet of jackals was studied in the Mediterranean lowlands of Fokida and Samos island, Greece, by analyzing 127 scats collected between January 2002 and May 2003. Across all seasons frequencies of food items show that the most common items were mammals (frequency 42.7%, biomass 69.8%) and birds (12.0%, biomass 27.7%). Although the frequencies of plant material (27.3%) and insects (18.0%) were quite high, their biomass contribution was low (1.7%, 0.8% respectively). Most of the biomass consumed composed of mammals of domestic livestock origin (55.9%) which were presumably scavenged. This reveals the importance of this food item to the opportunistic jackals in wildlife-poor ecosystems like the anthropogenic Mediterranean lowlands. The occurrence of small mammals in the scats was very low while very few traces of grass and human refuse (such as leftovers of meals, plastic, pieces of paper etc.) were found in the diet of jackals. Furthermore, the findings support the opportunistic nature of a species capable to exploit any easily available food source.