Diet, habitat use, and relative abundance of pampas fox (Pseudalopex gymnocercus) in northern Patagonia, Argentina

doi:10.1016/j.mambio.2004.11.019

Mammalian Biology

Volume 70, Issue 4, 13 July 2005, Pages 218-226

https://doi.org/10.1016/j.mambio.2004.11.019 Get rights and content

Abstract

Diet, habitat use and relative abundance of pampas fox Pseudalopex gymnocercus were studied in grassland, sand dune, and scrubland habitats, on the Bahía San Blas and Isla Gama Reserve, Argentina. Scat contents showed a generalist diet, where mammals, insects, and fruits were the main food items. Dietary composition differed among habitats; fruits were mainly consumed in sand dunes; insects, mammals, and fruits predominated in grassland; while insects and mammals were frequent in scrubland habitat. The European hare was the most common vertebrate prey and had the major contribution to the biomass of consumed prey. Pampas fox was the most common carnivore of the reserve and used all available habitats, frequenting more regularly scrubland and sand dune than grassland habitat.

Zusammenfassung

Nahrung, Habitatnutzung und relative Abundanz von Pampasfüchsen (Pseudalopex gymnocercus) im nördlichen Patagonien, Argentinien

Die Nahrung, Habitatnutzung und relative Abundanz von Pampasfüchsen Pseudalopex gymnocercus wurde auf Grasflächen, Sanddünen und in Strauchhabitaten des Bahía San Blas and Isla Gama Reserve, Argentinien untersucht. Die Analyse von Kotproben ergab eine typische Diät für Generalisten, wobei Säugetiere, Insekten und Früchte die wichtigsten Nahrungsbestandteile waren. Die Nahrungszusammensetzung unterschied sich zwischen verschiedenen Lebensräumen. Früchte wurden hauptsächlich in Sanddünen konsumiert, Insekten, Säugetiere und Früchte auf Grasflächen; und Insekten und Säugetiere in Strauchhabitaten. Der europäische Hase war die häufigste Beuteart unter den Wirbeltieren und stellte den Hauptanteil an der Biomasse genutzter Beute. Der Pampasfuchs ist das häufigste Raubtier im Reservat und nutzt alle vorhandenen Habitate, jedoch kommt er etwas häufiger in Strauchhabitaten und Sanddünen vor als auf Grasflächen.

Introduction

The pampas fox Pseudalopex gymnocercus is a common species along southern South America, showing a wide distributional range (Jimenez et al. 1996). This fox ranges through southern Brazil, Paraguay, northern Argentina, and Uruguay, and occurs in pampas, hills, deserts, and open forests (Nowak 1997). P. gymnocercus display all day activity (Brooks 1992), although they can be elusive during day hours in habitats where they are pursued (Redford and Eisenberg 1992). Food habits studies on this species are very scant (Márquez and Fariña 2003).

Pampas's foxes are persecuted because they are believed to prey on livestock (Alderton 1998, Nowak 1997). In northern Patagonia, fox poisoning is performed for this reason, even though no ecological studies on this fox were carried out in this region.

In this study we aim first to describe food habits of pampas foxes during the summer season, a period when the prey base is most diverse because of the occurrence of fruits in the field, and the manifestation of higher activity levels in many species of arthropods and ectothermic vertebrates. We aim also to evaluate pampas foxes’ use of three different habitats (grasslands, scrublands and sand dunes), and to compare their relative abundances with those of other mammalian carnivores across habitat types.

Section snippets

Study area

The study was conducted in the Bahía San Blas and Isla Gama Provincial Reserve (40°21′S, 62°23′W), northern Patagonia, Argentina. The reserve is located within the Monte Botanical province (Soriano 1983); but shrubby vegetation characteristic of this formation is reduced to small fragments due to extensive cattle and sheep raising in the region. Coastal grasslands constitute the dominant vegetation around the reserve. Annual precipitation is 345 mm, without considerable variation among climactic

Diet

We collected 469 scats of pampas fox throughout the study period; 67 in sand dunes (2.5 scats/day), 271 in grassland (7.7 scats/day) and 131 in scrubland (3.7 scats/day). Pampas fox's scats were located singly, over bare or grassy soil (24%), on vegetation (23%), along paths (18%), inside holes (7%), on baited stations (5%), on carcasses (4%); or clumped, in dens (3%), and in latrines (17%). Ten defecation spots or latrines were found in the grassland habitat and contained between 4 and 21

Diet

Activity indicators were more abundant in the grassland habitat (Fig. 2). The number of paths and intersections between paths were higher in grassland than in scrubland (Mann–Whitney, $U = 1191.0$ , 1230.5, respectively, $P < 0.0001$ ). Holes made by foxes were significantly more frequent in grassland than in scrubland and sand dunes (SNK tests, $P < 0.05$ ). In addition, fox's holes were more frequent in scrubland than in sand dunes (SNK test, $P < 0.05$ ). Significant differences in the number of carcasses and

Discussion

During the summer, Pseudalopex gymnocercus showed a generalist diet, including mammals, insects, and fruits as main food items; while birds, reptiles and carrion (cattle and fishes) were consumed in low proportion. This is consistent with results from other regions that also reported a generalist diet for pampas foxes (Crespo 1971). A recent study on dental morphology shows that the pampas fox is adapted to an omnivorous diet (Márquez and Fariña 2003), being consistent with our results and

Acknowledgements

A. Farías, U. Pardiñas, M. Barg, and J. Fariña helped with prey identification. A. Srur and L. Ricci kindly assisted with identification of plant species. We thank L. Lucifora for assistance in the field and his comments on the manuscript; and Heike K. Lotze for assistance in writing the German abstract.

References (31)

A.J. Novaro et al.
Ecological extinction of native prey of a carnivore assemblage in Argentine Patagonia
Biol. Conserv.
(2000)
D. Alderton
Foxes Wolves and Wild Dogs of the World
(1998)
M.I. Bellocq
Dieta de Athene cunicularia (Aves, Strigidae) y sus variaciones estacionales en ecosistemas agrarios de La Pampa, Argentina
Physis
(1988)
M.S. Bó et al.
Diet of long-winged Harrier (Circus buffoni) in Southeastern Buenos Aires Province, Argentina
J. Raptor Res.
(1996)
D.E. Brillhart et al.
Spatial and seasonal variation in prey use by coyotes in north-central Kansas
Southwest. Nat.
(1995)
D.M. Brooks
Notes on group size, density, and habitat association on the pampas fox (Dusicyon gimnocercus) in the Paraguayan Chaco
Mammalia
(1992)
M. Busch
Identificación de algunas especies de pequeños mamíferos de la Provincia de Buenos Aires mediante características de sus pelos
Physis
(1986)
C. Chehébar et al.
Guía para el reconocimiento microscópico de los pelos de los mamíferos de la Patagonia
Acta Vertebr.
(1989)
D. Choquenot et al.
Assessing lamb predation by feral pigs in Australia's semiarid rangelands
J. Appl. Ecol.
(1997)
A.P. Clevenger et al.
Brown bear (Ursus arctos L.) habitat use in the Cantabrian mountains, Spain
Mammalia
(1992)

J. Crespo

Ecología del zorro gris (Dusicyon gymnocercus antiquus), en la Provincia de La Pampa

Rev. Mus. Argent. Cienc. Nat. Bernardino Rivadavia (Ecol)

(1971)

C.P. Doncaster et al.

Feeding ecology of red foxes (Vulpes vulpes) in the city of Oxford, England

J. Mammalogy

(1990)

B. Efron

The Jackknife, the Bootstrap and other Resampling Plans

(1982)

K.G. Facure et al.

Food habits of the crab-eating fox Cerdocyon thous in an altitudinal forest of the Mantiqueira Range, southeastern Brazil

Mammalia

(2003)

Farías, A. A.; Kittlein, M. J. (2005): Cross-scale spatial variability in the diet of pampas foxes (Pseudalopex...

Cited by (33)

Spatio-temporal interactions of carnivore species in a coastal ecosystem in Argentina
2020, Ocean and Coastal Management
Citation Excerpt :
Although more data are needed to confirm it, these sites could also harbor a higher abundance and diversity of small vertebrates. Because L. gymnocercus readily eats carrion and has been reported to prey on several animals associated to saline water, such as crabs, crustaceans, and even fish (García and Kittlein, 2005; Lucherini and Luengos Vidal, 2008; Bossi et al., 2019), this canid could be expected to use the areas close to the shoreline more intensively than other carnivores. We found little support for this hypothesis.
Land-sea interface is an ecotone where the intersection of marine and terrestrial ecosystems create unique ecological conditions for terrestrial mobile species and freshwater-adapted organisms to exploit marine-derived food resources. Mammalian carnivores play an important role in almost any ecosystem where they live due to their top-down (or trophic cascade) effects on prey species and primary producers, thus structuring ecosystems along varied food-web pathways. We use camera trapping to study the patterns of coexistence, habitat use and activity pattern of carnivores species in a coastal area in southern Buenos Aires province, Argentina. We were able to detect five of the seven species of Mammalian carnivores being the Pampas fox Lycalopex gymnocercus and Geoffroy's cat Leopardus geoffroyi the two most common. Geoffroy's cat seems to use more intensively those areas close to the shoreline, while we found little support of it for Pampas fox; which seems to use more inland areas. Congruently, we found evidence of a lack of spatial and, to a lower extent, temporal avoidance between the two most common carnivore species of our study area. Our findings support those previous studies indicating that the coastal dunes have an important role in the conservation of the biodiversity of Buenos Aires province. Wildlife conservation is compatible with carefully-designed ecotourism and limited infrastructure development and this may be a unique chance for the areas of Buenos Aires coast that have not been affected yet by poorly planned, conservation-unfriendly urbanization.
Ecosystem services provided by wildlife in the Pampas region, Argentina
2020, Ecological Indicators
Citation Excerpt :
For instance, the removal of animal debris before putrefaction plays an important hygienic role, as it helps to stabilize food webs, accelerate nutrient recycling and remove potential sources of infectious disease transmission (Cortés-Avizanda et al., 2016; Sebastián-González et al., 2019; Whelan et al., 2008). The Chimango Caracara, the Southern crested Caracara (Biondi et al., 2005; Montalvo et al., 2011; Vargas et al., 2007), the Pampas Fox (Canel et al., 2016; Castillo et al., 2011; Farias and Kittlein, 2008; García and Kittlein, 2005) and the Molina's hog-nosed Skunk (Castillo et al., 2014) are facultative scavengers in the Pampas region. The carrion items found in their diets varied from domestic animals, such as cows (Bos taurus), sheep (Ovis aries), horses (Equus caballus) and pigs (Sus scrofa) to fish and birds.
The expansion and intensification of human activities in the Argentinean Pampas have affected birds and mammals that inhabit the agroecosystems, threatening their populations and aggravating their conflicts with humans. On the other hand, they play different roles in the provision of Ecosystem Services (ES). Therefore, identifying and understanding the relationships between species and humans, and the delivery of ES is crucial for sustainable management of the environment. The objectives of this study were to identify ecological functions of birds and mammals and its conflicts with human activities reported by previous articles in the Pampas region; and to link these ecological functions as indicators of the potential ES provided by these species. We performed two systematic and structured searches of articles using Scopus bibliographic database, one for the ecological functions and the second one for conflicts. From the first search, we found 145 studies and 34% of them reported ecological functions, 78% were about birds and the rest about mammals. The Regulation and Maintenance ES were the most reported type and involved the provision of nutrients and pest control, with birds of prey and carnivorous mammals as the most mentioned groups. Provisioning ES were related to the provision of leather from legal hunting and genetic material, and Cultural ES were associated to species conservation. From the conflict search, we found 23 studies that mentioned negative interactions in the Pampas region, mostly with birds and associated to agricultural production damages. Many species mentioned as important ES providers, are also involved in conflicts, causing some discomfort to people. Therefore, the integration of wildlife, with its benefits and damages, could be a powerful argument to achieve the coexistence of wildlife into a landscape shaped by anthropogenic activities.
Key to cranial and mandibular remains of non-flying small mammals from southern South America
2020, Journal of Archaeological Science: Reports
Citation Excerpt :
Small mammals were also used as proxy data for paleoenvironmental reconstruction, due to its usually narrow and specialized microhabitat requirements (e.g., Teta et al., 2005; Udrizar Sauthier, 2009; Pardiñas and Teta, 2013; Andrade and Monjeau, 2016). As small mammals are the most frequent prey items in the diet of many birds of prey and mammalian carnivores (e.g., Zapata et al., 2005; García and Kittlein, 2005; Andrade et al., 2010; Formoso et al., 2012), and even humans (Fernández, et al. 2017), their identification has important consequences in order to understand the trophic ecology of these predators. Diagnostic characters and accurate descriptions for different genera and species of small mammals are usually scattered throughout the literature and no single publication exists at present that could be used as a standard for identification.
Reliable identification of small mammal bone remains is crucial for several disciplines, including archaeology, biogeography, ecology, paleontology, taxonomy, and taphonomy. However, this issue is usually a challenging task, often complicated by the fragmentary nature of bone accumulations and/or by the taphonomic processes involved in the genesis of some assemblages. In this work, we provide dichotomous artificial keys for crania and mandibles of non-flying small mammal (<1000 g) genera of southern South America (i.e., southern Argentina and Chile). Keys are complemented with separate accounts for species identification, based on the cranial and dental features better preserved on fragmentary materials.
Geographic variation in skull shape and size of the Pampas fox Lycalopex gymnocercus (Carnivora: Canidae)in Argentina
2019, Mammalian Biology
Citation Excerpt :
The Pampas or gray fox L. gymnocercus from Argentina is a medium-sized fox (between 2.4–8 kg in weight, Lucherini et al., 2004), with an omnivorous diet based on resource availability (Lucherini and Luengos-Vidal, 2008; Sillero-Subiri, 2009). The diet of Pampas fox consists of rodents, lagomorphs, birds, carrion, vegetables and arthropods in various proportions, with a marked trend to the consumption of small mammals and lagomorphs as main food items (Marquet et al., 1993; Johnson and Franklin, 1994; Correa and Roa, 2005; García and Kittlein, 2005; Zapata et al., 2005; Varela et al., 2008; Zuñiga et al., 2008; Canel et al., 2016). The study of the correlation between diet and shape of the feeding apparatus indicated that omnivorous taxa display hypocarnivorous morphology, whereas those taxa that prey mainly on vertebrate flesh are called hypercarnivorous (see Ewer, 1973; Van Valkenburgh, 1989, 2007; Damasceno et al., 2013; Schiaffini and Prevosti, 2014; Meloro et al., 2015, 2017).
South American foxes are included in the monophyletic genus Lycalopex, with several recent species. Here, the influence of environment about cranial size and shape variations of Lycalopex gymnocercus was explicitly addressed. 3D landmark-based methodology was used to acquire morphometric data. Each record locality was georeferenced and assigned both environmental variables and ecoregion membership. Size and shape changes were analyzed with regression and redundancy analyses, including the study of -spatial autocorrelation. An association of smaller specimens with arid and colder environments was found. Bergmann’s rule does not hold for this species. Pampas foxes from humid and warm areas display morphological traits related to more carnivorous diets, whereas those from arid and cold environments should display more hypocarnivorous traits. We found that ˜15% of shape variation explained by environment was independent of allometry, suggesting that both are independent components of the total cranial shape in Pampas foxes.
Diet of the European badger (Meles meles) in the Republic of Ireland: A comparison of results from an analysis of stomach contents and rectal faeces
2011, Mammalian Biology
Citation Excerpt :
Within Europe, the badger (Meles meles) is wildly distributed and its diet has been studied in many parts of its range (Rodriguez and Delibes 1992; Martin et al. 1995; Roper and Lüps 1995; Goszczynski et al. 2000; Lanszki 2004; Rosalino et al. 2005; Cleary et al. 2009). When determining the composition of the badger's diet, most authors have relied on the analysis of faecal samples (Lanszki 2004; Garcia and Kittlein 2005; Rosalino et al. 2005; Sidorovich et al. 2006). One of the main difficulties affecting both qualitative, and especially, quantitative dietary analyses, is that highly digestible food items may be absent or under-represented in faeces, while indigestible items may be over-represented (Treacy and Crawford 1981).
The diets of mammals have been investigated primarily through the analysis of faecal samples. In our study we analysed both stomach contents, and rectal faeces from European badgers. This approach enabled a direct comparison of the information derived from these two sources. The dietary components found from each source were the same. However, it was found that, compared to stomach contents, the contribution to the diet, by volume, of plant litter, earthworms, Tipulid larvae and adult Carabid beetles were significantly overestimated by faecal analysis, while those of Noctuid larvae and Carabid beetle larvae were significantly underestimated. The analysis of stomach contents showed clear evidence of seasonality in the consumption of earthworms, Carabid beetle larvae, Tipulid larvae and Noctuid larvae. This seasonality was not as evident when the diet was inferred by the analysis of faeces. We propose that an analysis of stomach contents rather than of faeces, more accurately reflects the relative proportions of ingested food types, and the seasonality of the diet.
Activity, habitat use, density, and reproductive biology of the crab-eating fox (Cerdocyon thous) and comparison with the pampas fox (Lycalopex gymnocercus) in a Restinga area in the southern Brazilian Atlantic Forest
2009, Mammalian Biology
The ecology and reproductive biology of the crab-eating fox (Cerdocyon thous) and the pampas fox (Lycalopex gymnocercus) were studied in Itapuã State Park, an Atlantic Forest fragment. In this study we describe their activity patterns (diel, lunar, and seasonal), reproductive period, density, spatial distribution, and habitat overlap. The crab-eating fox was more abundant than the pampas fox, occurring in all types of habitats and overlapping with the pampas fox only in the southern portion of the study area, covered by open vegetation. Both canid species presented nocturnal habits and C. thous showed no significant differences in activity among lunar phases or else year season. The density of C. thous was estimated to be 0.78 ind/km². The crab-eating fox reproduced once a year, generating pups during spring (October to December). In comparison with C. thous populations from lower-latitude regions the relatively low density and one reproductive event per year that we observed are probably related to a colder climate, shorter photoperiod, and shortage of food resources in the winter, characteristic of southern Brazil.

View all citing articles on Scopus

View full text

Original investigationDiet, habitat use, and relative abundance of pampas fox (Pseudalopex gymnocercus) in northern Patagonia, Argentina

Abstract

Zusammenfassung

Introduction

Section snippets

Study area

Diet

Diet

Discussion

Acknowledgements

Biol. Conserv.

Foxes Wolves and Wild Dogs of the World

Dieta de Athene cunicularia (Aves, Strigidae) y sus variaciones estacionales en ecosistemas agrarios de La Pampa, Argentina

Physis

Diet of long-winged Harrier (Circus buffoni) in Southeastern Buenos Aires Province, Argentina

J. Raptor Res.

Spatial and seasonal variation in prey use by coyotes in north-central Kansas

Southwest. Nat.

Notes on group size, density, and habitat association on the pampas fox (Dusicyon gimnocercus) in the Paraguayan Chaco

Mammalia

Identificación de algunas especies de pequeños mamíferos de la Provincia de Buenos Aires mediante características de sus pelos

Physis

Guía para el reconocimiento microscópico de los pelos de los mamíferos de la Patagonia

Acta Vertebr.

Assessing lamb predation by feral pigs in Australia's semiarid rangelands

J. Appl. Ecol.

Brown bear (Ursus arctos L.) habitat use in the Cantabrian mountains, Spain

Mammalia

Ecología del zorro gris (Dusicyon gymnocercus antiquus), en la Provincia de La Pampa

Rev. Mus. Argent. Cienc. Nat. Bernardino Rivadavia (Ecol)

Feeding ecology of red foxes (Vulpes vulpes) in the city of Oxford, England

J. Mammalogy

The Jackknife, the Bootstrap and other Resampling Plans

Food habits of the crab-eating fox Cerdocyon thous in an altitudinal forest of the Mantiqueira Range, southeastern Brazil

Mammalia

Original investigation
Diet, habitat use, and relative abundance of pampas fox (Pseudalopex gymnocercus) in northern Patagonia, Argentina