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Emmanuel Serrano

The influence of landscape structure and host diet on parasite load of wildlife is still largely unknown. We studied a roe deer (Capreolus capreolus) population in a fragmented agricultural landscape in southern France to explore the... more
The influence of landscape structure and host diet on parasite load of wildlife is still largely unknown. We studied a roe deer (Capreolus capreolus) population in a fragmented agricultural landscape in southern France to explore the relationship of gastrointestinal nematode load with spleen mass (to index immunocompetence), faecal nitrogen (to index diet quality), landscape structure and age of 33 hunt-harvested roe deer. Gastrointestinal worm counts were negatively related to faecal nitrogen and spleen mass, explaining respectively 24.7% and 9.2% of the observed variability in parasite load. Landscape structure did not appear to have a direct influence on gastrointestinal worm counts, but since animals from more open areas have a diet that is richer in nitrogen, its influence may be indirect. In conclusion, in the study area, the colonisation of the agricultural landscape does not seem to have increased the risk of gastrointestinal nematode parasitism for roe deer, possibly because access to high-quality food enhances immunocompetence.
The influence of landscape structure and host diet on parasite load of wildlife is still largely unknown. We studied a roe deer (Capreolus capreolus) population in a fragmented agricultural landscape in southern France to explore the... more
The influence of landscape structure and host diet on parasite load of wildlife is still largely unknown. We studied a roe deer (Capreolus capreolus) population in a fragmented agricultural landscape in southern France to explore the relationship of gastrointestinal nematode load with spleen mass (to index immunocompetence), faecal nitrogen (to index diet quality), landscape structure and age of 33 hunt-harvested roe deer. Gastrointestinal worm counts were negatively related to faecal nitrogen and spleen mass, explaining respectively 24.7% and 9.2% of the observed variability in parasite load. Landscape structure did not appear to have a direct influence on gastrointestinal worm counts, but since animals from more open areas have a diet that is richer in nitrogen, its influence may be indirect. In conclusion, in the study area, the colonisation of the agricultural landscape does not seem to have increased the risk of gastrointestinal nematode parasitism for roe deer, possibly because access to high-quality food enhances immunocompetence.
Page 1. This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with... more
Page 1. This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. ...
The main aim of our work was to evaluate osteometry as a complementary tool for the early detection of Ammotragus lervia, an exotic ungulate, which currently shows an expanding trend in southeastern Spain. For this purpose, 142 metacarpi... more
The main aim of our work was to evaluate osteometry as a complementary tool for the early detection of Ammotragus lervia, an exotic ungulate, which currently shows an expanding trend in southeastern Spain. For this purpose, 142 metacarpi and 123 metatarsi from seven Iberian ungulate species were determined by means of a classification function. In a general way, this function works, but regarding related species (those very similar from a morphometrical view), correct determination was reached in only 44.4–90% of the cases. However, in these cases, we can use auxiliary criteria like sexually dimorphic traits, and reach 100% correct identification of bones.
Page 1. This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with... more
Page 1. This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. ...
The main aim of our work was to evaluate osteometry as a complementary tool for the early detection of Ammotragus lervia, an exotic ungulate, which currently shows an expanding trend in southeastern Spain. For this purpose, 142 metacarpi... more
The main aim of our work was to evaluate osteometry as a complementary tool for the early detection of Ammotragus lervia, an exotic ungulate, which currently shows an expanding trend in southeastern Spain. For this purpose, 142 metacarpi and 123 metatarsi from seven Iberian ungulate species were determined by means of a classification function. In a general way, this function works, but regarding related species (those very similar from a morphometrical view), correct determination was reached in only 44.4–90% of the cases. However, in these cases, we can use auxiliary criteria like sexually dimorphic traits, and reach 100% correct identification of bones.
Body size of large herbivores is a crucial life history variable influencing individual fitness-related traits. While the importance of this parameter in determining temporal trends in population dynamics is well established, much less... more
Body size of large herbivores is a crucial life history variable influencing individual fitness-related traits. While the importance of this parameter in determining temporal trends in population dynamics is well established, much less information is available on spatial variation in body size at a local infra-population scale. The relatively recent increase in landscape fragmentation over the last century has lead to substantial spatial heterogeneity in habitat quality across much of the modern agricultural landscape. In this paper, we analyse variation in body mass and size of roe deer inhabiting a heterogeneous agricultural landscape characterised by a variable degree of woodland fragmentation. We predicted that body mass should vary in relation to the degree of access to cultivated meadows and crops providing high quality diet supplements. In support of our prediction, roe deer body mass increased along a gradient of habitat fragmentation, with the heaviest deer occurring in the most open sectors and the lightest in the strict forest environment. These spatial differences were particularly pronounced for juveniles, reaching >3 kg (ca 20% of total body mass) between the two extremes of this gradient, and likely have a marked impact on individual fates. We also found that levels of both nitrogen and phosphorous were higher in deer faecal samples in the more open sectors compared to the forest environment, suggesting that the spatial patterns in body mass could be linked to the availability of high quality feeding habitat provided by the cultivated agricultural plain. Finally, we found that adults in the forest sector were ca 1 kg lighter for a given body size than their counterparts in the more open sectors, suggesting that access to nutrient rich foods allowed deer to accumulate substantial fat reserves, which is unusual for roe deer, with likely knock-on effects for demographic traits and, hence, population dynamics.
Parasites, as organisms with a particular way of life, form an important part of biodiversity, not only regarding the number of known species, but also because of their relevant role within ecological processes. These two facts should... more
Parasites, as organisms with a particular way of life, form an important part of biodiversity, not only regarding the number of known species, but also because of their relevant role within ecological processes. These two facts should justify conservation of parasites, at least within natural and protected areas. Little is known about such complex communities of parasites but they are often considered as pests, even out of the fields of public (human) health and animal production, that is, just in the natural environment or under natural conditions. It is increasingly assumed that wildlife diseases, including those produced by parasites, are one of the main bases for managing animal populations. Parasitic diseases may also be managed and, at this point, we can find multiple technical problems which, in certain occasions, lead into philosophical questions or true dilemmas. These considerations are illustrated by revising parasites of the Spanish ibex (Capra pyrenaica), an Iberian mountain ungulate the parasitofauna of which is relatively well known. As a big game species, its trophies become more and more appreciated. Therefore, human dimensions involved in management of its populations are considerably increased. Finally, reasons and opportunities for managing parasitic diseases affecting ibex are revised and discussed, under a global goal or perspective of conserving parasites within natural areas, particularly those that are protected.
Abstract Heterogeneity in host compatibility is one of the main hypotheses proposed to explain uneven resistance to parasites and uneven parasite load between hosts. It suggests that differences between hosts modulate their... more
Abstract Heterogeneity in host compatibility is one of the main hypotheses proposed to explain uneven resistance to parasites and uneven parasite load between hosts. It suggests that differences between hosts modulate their predispositions as suitable environments for ...
Blood samples were analysed from 175 shot Iberian ibexes, and good-quality samples were obtained in more than 56% of cases. Sixty-eight of these samples from healthy animals were then used to characterize standard values for the species.... more
Blood samples were analysed from 175 shot Iberian ibexes, and good-quality samples were obtained in more than 56% of cases. Sixty-eight of these samples from healthy animals were then used to characterize standard values for the species. Values for 10 blood parameters [monocytes, cholesterol, creatinine, albumin, beta-globulin, gamma-globulin, albumin/globulin (A/G) ratio, calcium (Ca), phosphates and iron (Fe)] from shot ibexes did not differ from those obtained from healthy captured and physically restrained animals. Blood samples from mange-infested ibexes (n=31) were also analysed and showed higher values for eosinophils and gamma-globulin than samples from healthy animals, but lower values for cholesterol, direct bilirubin, albumin, alpha-2-globulins and chloride. Values from blood parameters can provide useful information about the health and nutritional status of animals, and blood values may thus provide a complementary source of information for animals shot in Andalusia that will prove to be useful for monitoring the physiological status of ibex populations. The protocol described here provides guidelines for quick sample collection after an animal’s death and standardized instructions for sample storage, transport and analysis.
European legislation allows the official recognition of Trichinella-free pig holdings, provided Trichinella sp. infection is absent from humans and prevalence of Trichinella sp. infection in red foxes (Vulpes vulpes) is below 0.1% in the... more
European legislation allows the official recognition of Trichinella-free pig holdings, provided Trichinella sp. infection is absent from humans and prevalence of Trichinella sp. infection in red foxes (Vulpes vulpes) is below 0.1% in the area, region or country. Tibialis anterior muscle samples from 1,319 red foxes captured in Catalonia (NE Spain) between 1998 and 2007 were analyzed for Trichinella sp. using the digestion method. Four foxes resulted positive (one in 1999, one in 2002 and two in 2006), accounting for a low prevalence (0.3%). However, this prevalence was concentrated in mountain or rural areas with a low sample size, reaching high local prevalences. The two positive samples in 2006 were characterized as Trichinella britovi, and a sylvatic cycle of trichinellosis seems to occur, at least in the rural insufficiently sampled regions of Catalonia. Overall, the results obtained do not currently allow the establishment of Trichinella-free pig holdings in the study area, but further research is needed to better know the prevalence and cycle of Trichinella sp. in Catalonia.