GPS tracking of non-breeding ravens reveals the importance of anthropogenic food sources during their dispersal in the Eastern Alps

It has been postulated that red foxes (Vulpesvulpes) inhabiting Prince Edward Island National Park (Canada) make very little use of natural food sources and that anthropogenic food play an integral part in their diet. The use of anthropogenic food sources has also been associated with an increased number of fatal fox vehicle-collisions in the park. The main goal of this study was to examine the composition of the diet of foxes inhabiting Prince Edward Island National Park and to compare this diet with foxes found in other areas of the island. In particular, we examined the importance of anthropogenic food items in foxes inhabiting the national park. We analyzed 38 stomachs from foxes killed by trappers or vehiclesduring late fall and early winter within and outside the national park. Our results showed that rodents and vegetation were the most common food items present in fox stomachs whether the animals were obtained from within or outside the park. Values of coefficient of variation of food items found in fox stomachs indicated a great diversity in diet composition. However, only six stomachs contained anthropogenic food items. Stomachs of foxes killed by vehicles contained twice the amount of anthropogenic food items than those that were collected from trappers. Overall, our findings indicate that anthropogenic food items are only a minor component in the diet of foxes occurring within the park, at least during the period of time examined in this study. Future studies should examine diet composition during other seasons when the quantity and quality of anthropogenic food sources is different.

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Effects of Anthropogenic Food Sources on Movements, Survivorship, and Sociality of Common Ravens in the Arctic

The Condor ◽

10.1093/condor/103.2.399 ◽

2001 ◽

Vol 103 (2) ◽

pp. 399-404 ◽

Cited By ~ 5

Author(s):

Marco Restani ◽

John M. Marzluff ◽

Richard E. Yates

Keyword(s):

Human Population ◽

Age Groups ◽

Food Resources ◽

Food Sources ◽

The Arctic ◽

Corvus Corax ◽

Winter Climate ◽

Anthropogenic Food Sources ◽

Anthropogenic Food

Abstract We investigated survivorship, movements, and sociality of Common Ravens (Corvus corax) exploiting concentrated food resources at a landfill in Greenland. From 1992–1995 we banded 383 ravens: 365 were captured at the landfill and 18 were banded in nearby nests. Thirty-nine ravens were recovered, most by shooting (87%). Mean number of days survived post-banding (494 ± 97) did not differ among age groups, but a higher proportion of juveniles was recovered. Ravens migrated west and south to the coast during winter. No difference existed among age groups in mean distance between locations of banding and recovery (151 ± 31 km). Number of ravens congregating at the landfill declined during the study, coinciding with a decrease in the local human population. Harsh winter climate, limited ice-free land, and abundant human refuse influenced raven use of the wilderness landscape by facilitating the formation of large, nomadic foraging groups.

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Spatial Clustering by Red Deer and Its Relevance for Management of Chronic Wasting Disease

Animals ◽

10.3390/ani11051272 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1272

Author(s):

Atle Mysterud ◽

Isa Nergård Skjelbostad ◽

Inger Maren Rivrud ◽

Øystein Brekkum ◽

Erling L. Meisingset

Keyword(s):

Red Deer ◽

Chronic Wasting Disease ◽

Spatial Clustering ◽

Legal Regulation ◽

Food Sources ◽

Agricultural Fields ◽

Spatial Clusters ◽

Wasting Disease ◽

Anthropogenic Food Sources ◽

Anthropogenic Food

Herbivores like cervids usually graze on widely scattered forage, but anthropogenic food sources may cause spatial revisitation and aggregation, posing a risk for transmission of infectious diseases. In 2016, chronic wasting disease (CWD) was first detected in Norway. A legal regulation to ban supplemental feeding of cervids and to fence stored hay bales was implemented to lower aggregation of cervids. Knowledge of further patterns and causes of spatial revisitation can inform disease management. We used a recently developed revisitation analysis on GPS-positions from 13 red deer (Cervus elaphus) to identify the pattern of spatial clustering, and we visited 185 spatial clusters during winter to identify the causes of clustering. Anthropogenic food sources were found in 11.9% of spatial clusters, which represented 31.0% of the clusters in agricultural fields. Dumping of silage and hay bales were the main anthropogenic food sources (apart from agricultural fields), and unfenced hay bales were available despite the regulation. The probability of the clusters being in agricultural fields was high during winter. It may be necessary to find other ways of disposing of silage and enforcing the requirement of fencing around hay bales to ensure compliance, in particular during winters with deep snow.

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Patterns of Feeding by Householders Affect Activity of Hedgehogs (Erinaceus europaeus) during the Hibernation Period

Animals ◽

10.3390/ani10081344 ◽

2020 ◽

Vol 10 (8) ◽

pp. 1344 ◽

Cited By ~ 1

Author(s):

Abigail Gazzard ◽

Philip J. Baker

Keyword(s):

Food Sources ◽

Energy Deficit ◽

Net Energy ◽

Survey Period ◽

Erinaceus Europaeus ◽

Ecological Features ◽

Hibernation Period ◽

Negative Effect ◽

Anthropogenic Food Sources ◽

The Town

West European hedgehogs (Erinaceus europaeus) are likely to encounter unusual ecological features in urban habitats, such as anthropogenic food sources and artificial refugia. Quantifying how these affect hedgehog behaviour is vital for informing conservation guidelines for householders. We monitored hedgehog presence/absence in gardens in the town of Reading, UK, over the winter of 2017–2018 using a volunteer-based footprint tunnel survey, and collected data on garden characteristics, supplementary feeding (SF) habits, and local environmental conditions. Over a 20-week survey period, hedgehog presence was lowest between January and March. Occupancy analysis indicated that SF significantly affected hedgehog presence/absence before, during, and after hibernation. The number of nesting opportunities available in gardens, average temperatures, and daylength were also supported as important factors at different stages. In particular, our results suggest that SF could act to increase levels of activity during the winter when hedgehogs should be hibernating. Stimulating increased activity at this sensitive time could push hedgehogs into a net energy deficit or, conversely, help some individuals survive which might not otherwise do so. Therefore, further research is necessary to determine whether patterns of feeding by householders have a positive or negative effect on hedgehog populations during the hibernation period.

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How to catch red foxes red handed: identifying predation of freshwater turtles and nests

Wildlife Research ◽

10.1071/wr16066 ◽

2016 ◽

Vol 43 (8) ◽

pp. 615 ◽

Cited By ~ 4

Author(s):

Stuart J. Dawson ◽

Heather M. Crawford ◽

Robert M. Huston ◽

Peter J. Adams ◽

Patricia A. Fleming

Keyword(s):

Dna Analysis ◽

Red Fox ◽

Camera Traps ◽

Food Sources ◽

Freshwater Turtles ◽

Red Foxes ◽

Scat Analysis ◽

Artificial Nests ◽

Egg Shell ◽

Anthropogenic Food Sources

Context Predation is one of the key contributors to mortality in freshwater turtles. Confirming the identity of predators is an important step towards conservation management action. Throughout Australia, the red fox (Vulpes vulpes) is suspected to apply significant and unsustainable predation pressure to turtle populations, killing adults and depredating nests; however methods for confirming this are limited. Aims The present study used a range of methods to confirm predation of oblong turtle (Chelodina colliei) nests and adults by the introduced red fox. Methods First, depredated adult carapaces, and turtle egg-shell fragments from excavated nests were swabbed and analysed for trace DNA. Second, we used artificial turtle nests, monitored by camera traps, to analyse seasonal changes in the behaviour of foxes around sites where turtle nests are present, including over the nesting season. Last, we used scat analysis to identify the prevalence of turtle remains in fox diet. Key results Predominantly fox DNA was recovered from both adult carapaces and depredated eggs. In addition, camera traps recorded only foxes depredating artificial nests. Despite this evidence that foxes kill adults and excavated nests, we found that turtle remains were only a small part of the diet of foxes at this study site (hatchling or turtle egg shell were present in only 4% of 230 scats sampled). The diet of these foxes was largely anthropogenic-sourced foods, such as fruit (e.g. figs, grapes, melons; 81% of scats), sheep carrion (41%) and rodents (36%). Conclusions We conclude that DNA analysis, camera trapping and scat analysis are effective methods of identifying foxes as predators of adult turtle, and their nests. Furthermore, we found that anthropogenic foods (orchard crops, livestock or synanthropic species) may subsidise greater fox population size than might occur in their absence, thereby increasing potential pressure on these freshwater turtles. Implications Our findings give credence to the argument that foxes are effective predators of turtle adults and nests. In addition, the high proportion of anthropogenic food sources in the diet of foxes, and potential subsidisation, is an important consideration for land managers.

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An altered microbiome in urban coyotes mediates relationships between anthropogenic diet and poor health

Scientific Reports ◽

10.1038/s41598-020-78891-1 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Scott Sugden ◽

Dana Sanderson ◽

Kyra Ford ◽

Lisa Y. Stein ◽

Colleen Cassady St. Clair

Keyword(s):

Habitat Use ◽

Body Condition ◽

Isotope Analysis ◽

Food Sources ◽

Rrna Gene ◽

Generalist Species ◽

Fecal Microbiome ◽

Microbiome Composition ◽

Anthropogenic Food ◽

Urban Coyotes

AbstractGeneralist species able to exploit anthropogenic food sources are becoming increasingly common in urban environments. Coyotes (Canis latrans) are one such urban generalist that now resides in cities across North America, where diseased or unhealthy coyotes are frequently reported in cases of human-wildlife conflict. Coyote health and fitness may be related to habitat use and diet via the gut microbiome, which has far-reaching effects on animal nutrition and physiology. In this study, we used stomach contents, stable isotope analysis, 16S rRNA gene amplicon sequencing, and measures of body condition to identify relationships among habitat use, diet, fecal microbiome composition, and health in urban and rural coyotes. Three distinct relationships emerged: (1) Urban coyotes consumed more anthropogenic food, which was associated with increased microbiome diversity, higher abundances of Streptococcus and Enterococcus, and poorer average body condition. (2) Conversely, rural coyotes harbored microbiomes rich in Fusobacteria, Sutterella, and Anaerobiospirillum, which were associated with protein-rich diets and improved body condition. (3) Diets rich in anthropogenic food were associated with increased abundances of Erysipelotrichiaceae, Lachnospiraceae, and Coriobacteriaceae, which correlated with larger spleens in urban coyotes. Urban coyotes also had an increased prevalence of the zoonotic parasite Echinococcus multilocularis, but there were no detectable connections between parasite infection and microbiome composition. Our results demonstrate how the consumption of carbohydrate-rich anthropogenic food by urban coyotes alters the microbiome to negatively affect body condition, with potential relationships to parasite susceptibility and conflict-prone behavior.

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Recently-adopted foraging strategies constrain early chick development in a coastal breeding gull

PeerJ ◽

10.7717/peerj.7250 ◽

2019 ◽

Vol 7 ◽

pp. e7250 ◽

Cited By ~ 5

Author(s):

Alejandro Sotillo ◽

Jan M. Baert ◽

Wendt Müller ◽

Eric W.M. Stienen ◽

Amadeu M.V.M. Soares ◽

...

Keyword(s):

Urban Environments ◽

Food Sources ◽

Foraging Strategies ◽

Feeding Strategies ◽

Food Quantity ◽

Larus Fuscus ◽

Chick Development ◽

Foraging Niche ◽

Anthropogenic Food Sources ◽

Free Ranging

Human-mediated food sources offer possibilities for novel foraging strategies by opportunistic species. Yet, relative costs and benefits of alternative foraging strategies vary with the abundance, accessibility, predictability and nutritional value of anthropogenic food sources. The extent to which such strategies may ultimately alter fitness, can have important consequences for long-term population dynamics. Here, we studied the relationships between parental diet and early development in free-ranging, cross-fostered chicks and in captive-held, hand-raised chicks of Lesser Black-backed Gulls (Larus fuscus) breeding along the Belgian coast. This traditionally marine and intertidal foraging species is now increasingly taking advantage of human activities by foraging on terrestrial food sources in agricultural and urban environments. In accordance with such behavior, the proportion of terrestrial food in the diet of free-ranging chicks ranged between 4% and 80%, and consistent stable isotope signatures between age classes indicated that this variation was mainly due to between-parent variation in feeding strategies. A stronger terrestrial food signature in free-ranging chicks corresponded with slower chick development. However, no consistent differences in chick development were found when contrasting terrestrial and marine diets were provided ad libitum to hand-raised chicks. Results of this study hence suggest that terrestrial diets may lower reproductive success due to limitations in food quantity, rather than quality. Recent foraging niche expansion toward terrestrial resources may thus constitute a suboptimal alternative strategy to marine foraging for breeding Lesser Black-backed Gulls during the chick-rearing period.

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