Publicaciones Científicas

Linares, O. et al. (2020)

Linares, O., Carranza, J., Soliño, M., Delibes-Mateos, M., Ferreras, P., Descalzo, E., & Martínez-Jauregui, M. (2020). Citizen science to monitor the distribution of the Egyptian mongoose in southern Spain: who provide the most reliable information?. European Journal of Wildlife Research, 66(4), 1-5.

The Egyptian mongoose (Herpestes ichneumon L.) is a medium-size carnivore widely distributed in Africa and in a small part of southern Europe, the Iberian Peninsula, where mongoose populations have recently expanded. The mongoose is relatively easily detectable because of its diurnal habits and because it is the only species of Herpestidae occurring in the Iberian Peninsula. Therefore, its distribution could be monitored through citizen science. In this sense, information provided by stakeholders that make frequent use of natural environments, including hunters, landowners, or wildlife rangers, would be potentially very valuable. Nevertheless, the accuracy of the information provided by these stakeholders as regards mongoose occurrence has never been tested. To do so, we compared mongoose occurrences gathered through field transects (i.e., 2-km walking surveys in which direct observations and indirect signs were recorded) carried out in 218 Andalusian municipalities during 2010–2015 with those obtained through questionnaires conducted in 2016 to hunters (n = 251), landowners (n = 116), and wildlife rangers (n = 133). We did not find any significant difference between mongoose distribution estimated by the reference method (i.e., field surveys) and by questionnaire to wildlife rangers. In contrast, mongoose occurrences reported by hunters and landowners were significantly correlated among them, but not with those collected in field transects (nor with those provided by the rangers). This suggests that a participatory network for monitoring mongoose distribution could rely on the information provided by wildlife rangers. Previous studies showed that hunters can provide useful information from less accessible areas like private estates where official data are not collected. In this sense, our results suggest that further effort is needed to incorporate hunters and landowners in a participatory network to monitor mongoose distribution, and this could include collaborative actions to promote their involvement in addition to increasing their skills in mongoose detection.

de la Peña, E. et al. (2020)

de la Peña, E., Martín, J., Barja, I., Carranza, J. (2020)  Testosterone and the dark ventral patch of male red deer: the role of the social environment. Sci Nat 107, 18

The expression of male sexual traits, which is stimulated by testosterone, entails significant costs for individuals. Consequently, natural selection is expected to favour the modulation of sexual trait development according to the balance between its costs and benefits. The proportion of rivals in a population may affect this balance by increasing or decreasing the reproductive benefits associated with the development of sex traits. Here, we explore the relationship between testosterone level and sex trait size under two populational conditions of mate competition: fenced (i.e. high male-male competition; all male age groups are present) and unfenced (i.e. low competition; most males present are juveniles). Our model species is the Iberian red deer (Cervus elaphus hispanicus), and the sex trait is the dark ventral patch that males exhibit during the rutting season. Our results showed that the positive relationship between testosterone levels and the size of the dark ventral patch depends on the environmental level of male-male competition. Only in populations where the operational sex ratio was high (i.e. high proportion of rival males), individuals with high levels of testosterone developed the sex trait. Conversely, when mate competition was low, there was no significant relationship between testosterone level and trait size. This result reinforces the idea that the effect of testosterone in promoting the development of sex traits may be mediated by the intensity of mate competition in the population, as well as the role of sexual selection in the evolution of the dark ventral patch in red deer.

Pérez-Barbería, F.J. et al. (2020)

Pérez-Barbería, F.J., William Mayes, R., Giráldez, J., Sánchez-Pérez, D. (2020) Ericaceous species reduce methane emissions in sheep and red deer: Respiration chamber measurements and predictions at the scale of European heathlands. Science of The Total Enviroment  714,  136738

Despite the importance of atmospheric methane as a potent greenhouse gas and the significant contribution from ruminant enteric fermentation on methane emissions at a global scale, little effort has been made to consider the influence that different plant-based natural diets have on methane emissions in grazing systems. Heathland is an ericaceous dwarf-shrub-dominated habitat widespread across the northern hemisphere, in Europe, provides valuable ecosystem services in areas with poor soils, such as water flow regulation, land-based carbon skin, energy reservoir and habitat of key game species. We (i) measured methane emissions from red deer (Cervus elaphus) and sheep (Ovis aries) fed mixed diets of natural grass plus ericaceous species (either Calluna vulgaris or Vaccinium myrtillus) using open-circuit respiration chambers; and (ii) modelled the results to estimate methane emissions from red deer and sheep populations inhabiting heathland habitats across Europe under different scenarios of grass-based mixed diets with varying proportions of ericaceous species. Our results indicated that methane emissions per unit of digestible organic matter intake decreased as the proportion of ericaceous species in diet increased, but this relationship was complex because of the significant interaction between the proportion of ericaceous species in the diet and digestible organic matter intake. According to our estimates red deer and sheep populations across European heathlands produce 129.7 kt·y−1 methane (se = 1.79) based on a hypothetical grass-ericaceous species mixed diet containing 30% of ericaceous species; this is 0.5% of total methane emissions from human activity across Europe (24,755 kt·y−1), and a reduction in methane emissions of 63.8 kt·y−1 against the same deer and sheep populations, if assumed to consume a grass-only diet. We suggest the implementation of carbon credits as a measure to value the relevance of heathland systems to promote biodiversity and its potential contribution to reduce methane emissions in ruminant grazing systems.


Van Beeck Calkoen, S.T.S. et al. (2020)

Van Beeck Calkoen, S.T.S., Mühlbauer, L., Andrén, H., Apollonio, M., Balciauskasf, L., Belotti, E., Carranza, J.,  Cottam, J., Filli, F., Gatiso, T.T., Hetherington, D.,  Karamanlidis, A.A., Krofel, M., Kuehl, H.S., Linnell, J.D.C., Müller, J., Ozolinst, J., Premier, J., Ranc, N., Schmidt, K., Zlatanova, D., Bachmann, M., Fonseca, C., Lonescu, O., Nyman, M., Sprem, N., Sunde, P., Tannik, M., Heurich, M., (2020) Journal of Environmental Management 260, 110068

  1. Primary objectives of national parks usually include both, the protection of natural processes and species conservation. When these objectives conflict, as occurs because of the cascading effects of large mammals (i.e., ungulates and large carnivores) on lower trophic levels, park managers have to decide upon the appropriate management while considering various local circumstances.
  2. To analyse if ungulate management strategies are in accordance with the objectives defined for protected areas, we assessed the current status of ungulate management across European national parks using the naturalness concept and identified the variables that influence the management.
  3. We collected data on ungulate management from 209 European national parks in 29 countries by means of a large-scale questionnaire survey. Ungulate management in the parks was compared by creating two naturalness scores. The first score reflects ungulate and large carnivore species compositions, and the second evaluates human intervention on ungulate populations. We then tested whether the two naturalness score categories are influenced by the management objectives, park size, years since establishment, percentage of government-owned land, and human impact on the environment (human influence index) using two generalized additive mixed models.
  4. In 67.9% of the national parks, wildlife is regulated by culling (40.2%) or hunting (10.5%) or both (17.2%). Artificial feeding occurred in 81.3% of the national parks and only 28.5% of the national parks had a non-intervention zone covering at least 75% of the area. Furthermore, ungulate management differed greatly among the different countries, likely because of differences in hunting traditions and cultural and political backgrounds. Ungulate management was also influenced by park size, human impact on the landscape, and national park objectives, but after removing these variables from the full model the reduced models only showed a small change in the deviance explained. In areas with higher anthropogenic pressure, wildlife diversity tended to be lower and a higher number of domesticated species tended to be present. Human intervention (culling and artificial feeding) was lower in smaller national parks and when park objectives followed those set by the International Union for the Conservation of Nature (IUCN).
  5. Our study shows that many European national parks do not fulfil the aims of protected area management as set by IUCN guidelines. In contrast to the USA and Canada, Europe currently has no common ungulate management policy within national parks. This lack of a common policy together with differences in species composition, hunting traditions, and cultural or political context has led to differences in ungulate management among European countries. To fulfil the aims and objectives of national parks and to develop ungulate management strategies further, we highlight the importance of creating a more integrated European ungulate management policy to meet the aims of national parks.

Journal of Environmental Management; Ungulate management in European national parks Why a more integrated European policy is needed (1)


Pérez-González, J. & Carranza, J. (2020)

Pérez-González, J. &  Carranza, J. (2020) Offspring sired by subordinate red deer males under controlled conditions: did some females prefer not to mate with the alpha male? acta ethologica ISSN: 0873-9749 (Print) 1437-9546 (Online)

Both male-male competition and female choice are important forces in sexual selection that may act in concert. In red deer (Cervus elaphus), rutting activities related to male-male competition are highly conspicuous and have received most research attention. However, there is increasing evidence that females can gain by selecting mates. Due to the additive genetic benefits of a sire’s dominance rank, females may prefer them as mates, so that selection for male traits associated with dominance can be reinforced by female choice. On the other hand, recent evidence suggests that females might prefer male features not related to dominance and thus affect the distribution of mating outcomes. This predicts mating with less dominant males, but no study has so far investigated to which extent some females may do so when the dominant male is available. Here we use controlled captivity conditions to study whether females mate with subordinate males when dominant males are present. By means of parentage analyses conducted after genotyping the offspring, we found that dominant males did not sire all the offspring, the mean percentage of offspring sired by subordinate males being 13.03%. This result has consequences for the evolutionary reinforcement of components of sexual selection in red deer and might be used as a starting point for future studies on the red deer mating system and sexual selection.

de la Peña, E. et al. (2020)

de la Peña, E., Martín, J., Barja, I., Pérez-Caballero, R., Acosta, I. & Carranza, J. (2020) The immune challenge of mating effort: steroid hormone profile, dark ventral patch and parasite burden in relation to intrasexual competition in male Iberian red deer

Testosterone secretion may regulate the reproductive effort and the development of sexual traits, but it may also involve costs at the immunological and metabolic levels.  However, the evidence for this trade-off in wild populations is scarce. Similarly, cortisol also plays an important role in mediating the reproductive and immune functions. In this study, we analyzed whether the endoparasite burden relates to hormonal levels (fecal testosterone and cortisol metabolites) and/or morphological sexual traits (size of the dark ventral patch, a trait that indicates reproductive effort in males) in male Iberian red deer (Cervus elaphus hispanicus). For this purpose, we sampled male red deer harvested during hunting actions in two types of populations in southwestern Spain that differed in structure affecting the level of male-male competition for mates. We used coprological analyzes to estimate the parasite burden mainly of gastrointestinal and bronchopulmonary nematodes and of protozoa, and assessed testosterone and cortisol metabolite levels from fecal pellets. We found a positive relationship of host parasitation with both testosterone levels and the size of the dark ventral patch, but these relationships depended on the intensity of male-male competition in the population, being only found under the high-competition level. These results are discussed under the hypothesis of the testosterone immunocompetence handicap, suggesting a cost at the immunological level, and, therefore, higher susceptibility to parasite infection in males that make a greater reproductive effort. However, this effect seems to be modulated by the social environment (male-male competition) that might lead to different optima in testosterone production and sexual trait development

de la Peña, E. et al. (2019)

de la Peña, E., Martín, J. & Carranza, J. (2019) The intensity of male-male competition may affect chemical scent constituents in the dark ventral patch of male Iberian red deer. PLoS ONE 14(9), e0221980.

During the mating season, Iberian red deer males (Cervus elaphus hispanicus) present a large visible dark ventral area in their abdomen. This characteristic dark-haired area is formed by the impregnation of the hair with sprayed urine and gland secretions and contains volatile compounds that can be used in intraspecific communication. Here, we used gas chromatography-mass spectrometry (GC-MS) to describe the lipophilic chemicals from the dark ventral patch of males from different populations with different levels of intrasexual competition. Amongst all the compounds found, m-cresol, benzoic acid, cholesterol and 4hydroxy-benzenopropanoic acid were the most abundant. The proportions of these compounds varied with age as well as with the level of intra-sexual competition, independently of age. In particular, red deer males experiencing higher intra-sexual competition had lower proportions of aromatic compounds (especially m-cresol) but higher proportions of carboxylic acids on their dark bellies. Males in a high male-male competition situation, invest in volatile compounds that can reveal their age, dominance status and condition, and that, in addition, enhance this signal. On the contrary, males from low intra-sexual competition populations have chemical profiles more characteristic of young individuals. This research shows a first glance of how secretion of volatile compounds of male deer can be modulated due to the intensity of male-male competition in the population.


Campos, P. et al. (2019)

Campos, P., Caparrós, A., Oviedo, J.L., Ovando, P., Álvarez-Farizo, B., Diaz-Balteiro, L., Carranza, J., et al. (2019). Bridging the Gap Between National and Ecosystem Accounting Application in Andalusian Forests, Spain. Ecological Economics 157: 218-236.

National accounting either ignores or fails to give due values to the ecosystem services, products, incomes and environmental assets of a country. To overcome these shortcomings, we apply spatially-explicit extended accounts that incorporate a novel environmental income indicator, which we test in the forests of Andalusia (Spain). Extended accounts incorporate nine farmer activities (timber, cork, firewood, nuts, livestock grazing, conservation forestry, hunting, residential services and private amenity) and seven government activities (fire services, free access recreation, free access mushroom, carbon, landscape conservation, threatened biodiversity and water yield). To make sure the valuation remains consistent with standard accounts, we simulate exchange values for non-market final forest product consumption in order to measure individual ecosystem services and environmental income indicators. Manufactured capital and environmental assets are also integrated. When comparing extended to standard accounts, our results are 3.6 times higher for gross value added. These differences are explained primarily by the omission in the standard accounts of carbon activities and undervaluation of private amenity, free access recreation, landscape and threatened biodiversity ecosystem services. Extended accounts measure a value of Andalusian forest ecosystem services 5.4 times higher than that measured using the valuation criteria of standard accounts.



Galván, I. et al. (2019)

Galván, I., Solano, F., Zougagh, M., de Andrés, F., Murtada, K., Ríos, A., de la Peña, E. & Carranza, J. (2019). Unprecedented high catecholamine production causing hair pigmentation after urinary excretion in red deer. Cellular Molecular Life Science 76, 397-404.

Hormones have not been found in concentrations of orders of magnitude higher than nanograms per milliliter. Here, we report urine concentrations of a catecholamine (norepinephrine) ranging from 0.05 to 0.5 g/l, and concentrations of its metabolite DL-3,4-dihydroxyphenyl glycol (DOPEG) ranging from 1.0 to 44.5 g/l, in wild male red deer Cervus elaphus hispanicus after LC–MS analyses. The dark ventral patch of male red deer, a recently described sexually selected signal, contains high amounts of DOPEG (0.9–266.9 mg/l) stuck in the hairs, while DOPEG is not present in non-darkened hair. The formation of this dark patch is explained by the chemical structure of DOPEG, which is a catecholamine-derived o-diphenol susceptible to be oxidized by air and form allomelanins, nitrogen-free pigments similar to cutaneous melanins; by its high concentration in urine; and by the urine spraying behavior of red deer by which urine is spread through the ventral body area. Accordingly, the size of the dark ventral patch was positively correlated with the concentration of DOPEG in urine, which was in turn correlated with DOPEG absorbed in ventral hair. These findings represent catecholamine concentrations about one million higher than those previously reported for any hormone in an organism. This may have favored the evolution of the dark ventral patch of red deer by transferring information on the fighting capacity to rivals and mates. Physiological limits for hormone production in animals are thus considerably higher than previously thought. These results also unveil a novel mechanism of pigmentation based on the self-application of urine over the fur.



Carranza, J. et al. (2018)

Carranza, J., Yoong, W.A., Caño Vergara, B., Briones, A., & Concha Mateos, C. (2018) Grass greenness flush can influence breeding phenology and fertility in equatorial thoroughbred mares in the absence of photoperiod variation. Animal Science Journal  89, 919–924

Reproductive phenology is an important trait subjected to natural selection. Current horses in America belong to the Palearctic original populations after being introduced by European colonizers. Photoperiod variation is the main environmental factor for the adjustment of reproductive timing in horses, but is absent in equatorial areas. Here we hypothesize that seasonality of green-grass availability may influence breeding phenology in equatorial regions. We used data of 929 services to mares from 2006 to 2011 in a thoroughbred equine exploitation in Ecuador that experienced strong grass seasonality. Actual births could not be used to infer natural phenology because they were influenced by management decisions. Instead, we used variations in the probability of pregnancy after a service as a measure of the natural tendency of mares to show breeding phenology. We found that although managers tended to schedule pregnancies in two periods within the year, mares were more prone to become pregnant after the increase in grass greenness that takes place at the beginning of the year (February). Our finding has potential applications to improve the success of services and the welfare of animals, by providing green-grass stimuli in the appropriate season.