101 research outputs found

    Can Iberian red deer (Cervus elaphus hispanicus) discriminate among essential minerals in their diet?

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    Optimal foraging predicts that animals should be able to assess the content of important nutrients in food. Ungulates discriminate salt and P, but discrimination of other minerals is controversial even though they are also essential and often limiting. Animal scientists have explained this taste through palatability, which predicts the same pattern of discrimination for calves and hinds and greater consumption by the latter. Social learning may also be involved, predicting a correlation between mother and calf and less consumption by the latter. The present study examines the consumption behaviour of free-choice supplemented minerals by hinds and calves of Iberian red deer (Cervus elaphus hispanicus) to discern between these hypotheses. Behavioural indices of intake correlated with actual mineral consumption (P,0·001). Mother and calf behavioural indices correlated only for salt-mixed minerals. Calves showed overall behavioural indices of consumption greater than hinds (P,0·01 and P,0·001), and also for all single supplements except NaCl, as expected from growth needs and in contrast to the palatability hypothesis. Calves showed a greater consumption of CuSO4 and lower of Na2SeO3 than pure salt. Hinds showed a different pattern, ingesting lower amounts of all minerals except CuSO4 and salt. Additional analyses also showed discrimination between minerals unmixed with salt, such as CaHPO4 and CaCO3 (P¼0·012 and P¼0·020). The greater intake of growing calves and the different consumption patterns for hinds and calves suggest that deer can discriminate among minerals, and that they do not consume minerals for their palatability or driven by social learning. Therefore, deer may be selecting minerals according to nutritional requirements.The present study was supported by projects CGL2008-00749/BOS (Ministerio de Ciencia e Innovacion-Fondo Europeo de Desarrollo Regional) and PC108-0115 (Junta de Comunidades de Castilla-La Mancha).Peer Reviewe

    Perceptions and uses of pangolins (Pholidota) among remote rural communities in the Republic of the Congo: A baseline study from the Odzala‐Kokoua National Park

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    Habitat loss and overexploitation are the most severe threats to wild animals in Central Africa. One mammalian group under pressure from hunting is the Pholidota (pangolins), with three species of pangolin inhabiting the region. While local uses of pangolins have been investigated in several Central African countries, data originating from the Republic of the Congo are lacking. To address this knowledge gap, we conducted a semistructured questionnaire survey in 65 rural communities around the Odzala-Kokoua National Park. Our research focused on collecting baseline information on local knowledge of species ecology, and perceived economic values and uses of pangolins in local communities. We identified significant differences in our data corresponding to respondents' sociocultural and demographic profiles in the surveyed villages. Recognition of pangolins was high (98.2%), we recorded 22 traditional medicinal or cultural uses of pangolins by respondents, and the taste of pangolin meat was ranked highly (71.3%). Respondents based along the northern boundary of the park were more familiar with pangolins and the market value of their meat and scales, which could be due to better quality roads in the area and proximity to Cameroon. We then provide guidelines for further research to better understand the dynamics of local use, needed for conservation policy and actions

    Habituating to handling: Factors affecting preorbital gland opening in red deer calves

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    The preorbital gland plays not only an olfactory role in cervids but also a visual one. Opening this gland is an easy way for the calf to communicate with the mother, indicating hunger/satiety, stress, pain, fear, or excitement. This information can be also useful for farm operators to assess how fast the calves habituate to handling routines and to detect those calves that do not habituate and may suffer chronic stress in the future. Thirty-one calves were subjected to 2 consecutive experiments to clarify if observing preorbital gland opening is related to habituation to handling in red deer calves (Cervus elaphus). Calves were born in 3 different paddocks, handled as newborns (Exp. 1), and then subjected to the same routine handling but with different periodicity: every 1, 2, or 3 wk (Exp. 2). In Exp. 1, preorbital gland opening was recorded in newborns during an initial handling (including weighing, ear tagging, and sex determination). Preorbital gland opening occurred in 93% of calves during this procedure and was not affected by sex, time since birth, or birth weight. Experiment 2 consisted of measuring preorbital opening during the same routine handling (weighing, blood sampling, and rump touching to assess body condition) when calves were 1, 3, and 5 mo old. Binary logistic regression showed that gland opening was associated with habituation to handling, since at 1 and 3 mo the probability of opening the gland decreased with the number of handlings that a calf experienced before (P = 0.008 and P = 0.028, respectively). However, there were no further changes in preorbital gland opening rate in the 5-mo-old calves (P = 0.182). The significant influence of the number of previous handlings on the probability of opening the preorbital gland was confirmed through generalized linear model with repeated measures (P = 0.007). Preorbital gland opening decreased along the phases of the study. Nevertheless, we found a significant trend in individuals to keep similar opening patterns (intraclass correlation coefficient = 0.807, P < 0.001), which suggests that the more stressed individuals can be detected with this method. Therefore, we conclude that preorbital gland opening during routine handlings is related to the number of previous handlings, and thus it can be used as an indicator of lack of habituation to handling in farmed cervids.This study was supported by projects AGL2012-38898 (Ministry of Economy and Competitiveness, Spain), MZERO0714‏ (Ministry of Agriculture, Czech Republic), CIGA20145001 (Czech University of Life Sciences, Czech Republic), and IGA no. 20145026 (Faculty of Tropical AgriSciences, Czech Republic).Peer Reviewe

    Plasmatic protein values in captive adult Iberian red deer stags (Cervus elaphus hispanicus)

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    The aim of this study was to assess the time trend of plasmatic proteins in red deer stags. Blood samples were taken monthly from 17 male red deer for 22 months. Total plasmatic determination and protein electrophoresis were performed. Plasmatic proteins showed minimum values during spring and summer and a maximum at the peak of the mating period. Total globulins, β and γ, followed a pattern similar to that observed for total proteins, whereas α1 and α2 globulins showed no seasonal variations. Albumin showed higher values in early spring and summer and lower values at the beginning of autumn, coinciding with the mating season. These seasonal changes in plasmatic proteins should be taken into account when assessing blood protein analysis results.This study was funded by projects AGL2007-63838/gan, PBI-05-040, PAC 06-01304298 and PET2006-0263 and MICINN (PTQ 09-02-01923).Peer Reviewe

    Spatiotemporal behavior of predators and prey in an arid environment of Central Asia

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    The mechanisms of interactions between apex and smaller carnivores may range from competition to facilitation. Conversely, interactions between predators and prey are mainly driven by the prey reducing the likelihood of encounters with predators. In this study, we investigated (1) the spatiotemporal interactions between an apex (the snow leopard) and a meso-predator (the red fox), and (2) the temporal interactions between the snow leopard and its potential prey (Siberian ibex, argali, Asian wild ass, Tolai hare) through camera trapping in the Mongolian Great Gobi-A. The probability of occurrence for the red fox was higher in the presence of the snow leopard than in its absence. Moreover, the red fox activity pattern matched that of the snow leopard, with both species mostly active at sunset. This positive spatiotemporal interaction suggests that the presence of the snow leopard may be beneficial for the red fox in terms of scavenging opportunities. However, other explanations may also be possible. Amongst prey, the Siberian ibex and the argali were mainly active during the day, whereas the Asian wild ass and the Tolai hare were more nocturnal. These findings suggest that potential prey (especially the Siberian ibex and the argali) may shape their behavior to decrease the opportunity for encounters with the snow leopard. Our results have revealed complex interactions between apex and smaller predators and between apex predator and its potential prey

    Manganese supplementation in deer under balanced diet increases impact energy and contents in minerals of antler bone tissue

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    Bone ash, collagen, Ca and P composition, are considered the main factors affecting mechanical properties in bones. However, a series of studies in bone and antler have shown that some trace minerals, such as manganese, may play a role whose importance exceeds what may be expected considering their low content. A previous study showed that a reduction in manganese in antlers during a year of late winter frosts led to generalized antler breakage in Spain, which included a reduction of 30% of cortical thickness, 27% reduction in impact energy, and 10% reduction in work to peak force. Starting for this observation, we experimentally studied the effects of manganese supplementation in adults and yearling (yearlings) red deer under a balanced diet. Subjects were 29 deer of different age classes (adult n = 19, yearlings n = 10) that were divided in a manganese injected group (n = 14) and a control group (n = 15). Antler content in ashes and minerals, intrinsic mechanical properties and cross section structure were examined at 4 points along the antler beam. A one way ANOVA (mean per antler) showed that in yearlings, manganese supplementation only increased its content and that of Fe. However, in adults, Mn supplementation increased the mean content per antler of Ca, Na, P, B, Co, Cu, K, Mn, Ni, Se (while Si content was reduced), and impact work but not Young's modulus of elasticity, bending strength or work to peak force. A GLM series on characteristics in the uppermost part examined in the antler, often showing physiological exhaustion and depletion of body stores, showed also a 16% increase in work to peak force in the antlers of the treated group. Thus, manganese supplementation altered mineral composition of antler and improved structure and some mechanical properties despite animals having a balanced diet.Funding was provided by Ministerio de Economía y Competitividad, Government of Spain (MINECO): Project AGL2012-38898 to TLC, AG, LG, FC, JC; Consejería de Educación y Deportes de Castilla-La Mancha: Project PEII-2014-004-P to LG TLC AG.Peer Reviewe

    Use of Aerial Laser Scanning to Assess the Effect on C Sequestration of Oak (Quercus ilex L. subsp. ballota [Desf.]Samp-Q. suber L.) Afforestation on Agricultural Land

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    Conversion of agricultural lands to forest plantations to mitigate rising atmospheric carbon dioxide (CO2) has been proposed, but it depends on accurate estimation of the on-site carbon (C) stocks distribution. The use of aerial laser scanning (ALS) data is a rapidly evolving technology for the quantification of C stocks. We evaluated the use of allometric models together with high-density ALS data for the quantification of biomass and soil C stocks in a 14-year-old Quercus ilex and Q. suber plantation in Southwestern Spain. In 2010, a field survey was performed and tree dasometric and biomass variables were measured. Forty-five soil profiles (N = 180 soil samples) were taken systematically and the soil organic C content (SOC) was determined. Biomass and soil organic C values were regressed against individual dasometric variables and total tree height was used as a predictor variable. Aerial laser scanning data were acquired with a point density of 12 points m−2. Relationships among ALS metrics and tree height were determined using stepwise regression models and used in the allometric models to estimate biomass and SOC C stocks. Finally, a C stock map of the holm-cork oak cover in the study area was generated. We found a tree total biomass of 27.9 kg tree−1 for holm oak and 41.1 kg tree−1 for cork oak. In the holm oak plantation, the SOC content was 36.90 Mg ha−1 for the layer 0–40 cm (SOC40) under the tree crown and 29.26 Mg ha−1 for the inter-planted area, with significant differences from the reference agricultural land (33.35 Mg ha−1). Linear regression models were developed to predict the biomass and SOC at the tree scale, based on tree height (R2 >0.72 for biomass, and R2 >0.62 for SOC). The overall on-site C stock in the holm-cork oak plantation was 35.11 Mg ha−1, representing a net C stock rise of 0.47 Mg ha−1 yr−1. The ALS data allows a reliable estimation of C stocks in holm and cork oak plantations and high-resolution maps of on-site C stocks are useful for silvicultural planning. The cost of ALS data acquisition has decreased and this method can be generalised to plantations of other Mediterranean species established on agricultural lands at regional scales. However, an increase of filed data and the availability of local biomass and, in particular, SOC will improve accurate quantification of the C stocks from allometric equations, and extrapolation to large planted areas

    Tarentola and other gekkonid records from Djebel Ouarkziz (SW Morocco)

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    Tarentola mauritanica pallida was recorded for the first time far inland in the Djebel Ouarkziz and Oued Dr&acirc;a area, in south-western Morocco. The taxonomic characters proposed to identify this subspecies, T. m. juliae, and T. boehmei are discussed in view of the specimens observed during this survey. Other observations of gekkonid lizards in this area are also reported

    The Many Axes of Deer Lactation

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    In undomesticated animals information about the production and composition of milk over time is still scarce. In general, for most mammals it is known that milk composition changes across lactation, is different for male and female offspring, and even that marsupials, such as kangaroos, can simultaneously produce milk of different compositions for young of different ages. Such parallel milk production of differing compositions has not yet been studied in single-offspring placental mammals, but may help to explain behavioural processes like allosuckling (feeding the young of other adults) and lateralized suckling preferences. In this study we analysed the production and composition of milk in red deer throughout the lactation period and now confirm for the first time that there are axial differences present. The front teats, which are the favoured suckling positions of the deer?s offspring, produce milk with a greater protein-to-fat ratio. Also, from the beginning of lactation the yield is greater on the left side, the side preferred by calves in all of the studied species, both at population and individual level. The links between milk production and calf behaviour in deer deserve further stud

    Morphology, chemical composition, mechanical properties and structure in antler of Sardinian red deer (Cervus elaphus corsicanus)

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    The deer population present in Sardinia and Corsica represents an endemic subspecies Cervus elaphus corsicanus. We describe for the first time the characteristics of cast antlers of Sardinian red deer from the forest complex Sette Fratelli, south-east part of the island. Moreover, we describe the material mechanical properties, the structural ones, and the mineral profile of antlers from adults, comparing them with the antler characteristics of the subspecies C. e. hispanicus examined exactly with the same methodology. Sixty-one deer casted antlers were collected and classified as belonging to adults (35) or sub-adults (26). A first part of the study described the common features of the antlers of sub-species C. e. corsicanus through the analysis of morphology in all deer antlers. Subsequently, a more detailed study used 12 adult deer antlers for a destructive analysis. Statistical comparisons were conducted using ANOVAs between characteristics of the two age subgroups, and using Pearson´s correlation coefficients between the antlers morphological variables. In general, morphological antler measures had greater values in adults than in sub-adults. In comparison with Iberian deer, Sardinian adult antlers have a more simple structure with lower values in morphological features, mechanical properties and structural characteristics
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