Intermediate Feeders Research Articles

A pilot study on dietary and faecal calcium/phosphorus ratios in different types of captive ruminating herbivores.

Quantitative differences in calcium and phosphorus metabolism between domestic species exist and can be visualised using data on calcium and phosphorus intake and faecal excretion. The parameter for analysing the results was defined as Δ = dietary calcium/phosphorus (Ca/P) ratio – faecal Ca/P ratio. In previous studies, hindgut fermenters had significantly higher Δ values than ruminants (sheep, cattle, goats), which was explained by the high calcium digestibilities in hindgut fermenters in contrast to highly efficient phosphorus recycling in ruminants. The first hypothesis of the present study was that different types of ruminants (grazer, browser, intermediate feeder) would show differences in Δ as a proxy for quantitative calcium and phosphorus metabolism. The second hypothesis was that camelids as functional, but not taxonomic ruminants would show Δ values similar to ruminants. We used herbivorous zoo animals (17 species, hindgut and foregut fermenters), which were kept on their regular diet without variation for 1 week. Then, faecal samples were obtained from the individual animals. Feed items and faecal samples were analysed for calcium and phosphorus, and dietary and faecal Ca/P ratios as well as Δ were calculated. A comparison of the species groups (one‐way ANOVA on ranks, p < 0.05) showed that zoo hindgut fermenters had significantly higher Δ values (0.67 ± 0.34) than camelids and zoo ruminants (–1.07 ± 0.35 and –1.87 ± 1.56). There was no significant difference between camelids, grazers (–1.49 ± 1.31), browsers (–1.63 ± 0.88) and intermediate feeders (–2.11 ± 1.76). The ruminant species from this study had markedly lower Δ than domestic ruminants from literature data. Especially intermediate feeders had low Δ, possibly due to more efficient phosphorus recycling than the domestic ruminants.

Diet composition of Korean water deer (Hydropotes inermis argyropus) from the Han River Estuary Wetland in Korea using fecal DNA

Abstract To investigate the foraging preferences of the Korean water deer (Hydropotes inermis argyropus) from the Janghang wetlands located in Han River estuary in South Korea, we elucidated their diet compositions using DNA extracted from their fecal samples. Samples were collected from the Janghang wetlands from June 2013 to January 2015. For dietary analysis, we amplified the internal transcribed spacer 2 (ITS2) and the large subunit of ribulose-1,5-bisphosphate carboxylase (rbcL) regions, followed by cloning and sequencing. We were able to detect 20 families and 35 genera of plants from 77 fecal samples, showing that water deer in the Janghang wetlands mainly preferred Salicaceae (27.5%), Fabaceae (17.5%), and Poaceae (14.2%). In winter, the relative frequency of woody plant detection (81.3%) was much higher than that in other seasons. Our results suggest that Korean water deer in Janghang wetlands browse or graze depending on the locally-available plants species in their habitat as intermediate feeders. Non-invasive approaches using fecal samples could be applied to study food webs of various species and ecosystems for conservation and management of wildlife.

A new method to determine the diet of pygmy hippopotamus in Taï National Park, Côte d’Ivoire

AbstractDiet determination of endangered species is an essential element in defining successful conservation strategies and optimising captive breeding programmes. In this study, we developed a new diet identification system, derived from standard faecal analysis, to determine the diet of an elusive and endangered herbivore, the pygmy hippopotamus (Choeropsis liberiensis). We collected faecal samples from 10 free‐ranging individuals covering a combined home range area of about 50 km2 in Taï National Park, Côte d’Ivoire. In subsequent laboratory analyses, we extracted a large number of leaf epidermis fragments from spatially separated faecal samples and compared them with a reference plant database. Using Multiple Correspondence Analysis (MCA) of epidermis fragments combined with direct visual inspection, we identified the most frequently consumed plant species, which revealed that pygmy hippopotami qualified as intermediate feeders. Their diet was based on at least seven species of monocotyledonae, dicotyledonae and fern groups, with a preference for a small number of other plant species. We evaluate the merit of our method and discuss our findings for developing effective conservation and captive breeding strategies in an endangered species with a wild population of less than 2500 adult individuals.

Consequences of Increases in Ambient Temperature and Effect of Climate Type on Digestibility of Forages by Ruminants: A Meta-Analysis in Relation to Global Warming.

Simple SummaryThis work assessed how the digestion of feeds by cud-chewing animals (ruminants) is affected by animal and feed factors, ambient temperature (AT), and climatic region. The motive for this study was to simulate how forage quality and digestibility would respond under future climate change scenarios. This work allows for predictions to be made on the possible impacts of AT on the digestibility of feeds (viz. roughages, grains, leaves, stems, fruits, and concentrate formulations) consumed by ruminants. This would help farmers to plan and implement strategies for improving feed quality and to align feeding management to ensure improved growth response of ruminant livestock. Increasing AT reduced digestibility parameters consequent upon higher lignification of plant material. The amount of feed that can be potentially digested in a ruminants’ stomach (potential degradability (PD) were highest for concentrates and mixed diets compared to roughages. Potential degradability was lowest for studies carried out in tropical and arid climates compared to cold and temperate climates. Animals fed on diets classified as browse had similar PD compared to those fed on non-browses. Ensilaged feeds had similar PD compared to non-silages. A 1 °C increase in ambient temperature decreased PD by 0.55%, while the fibre content of feeds was projected to increase by approximately 0.4%.This meta-analysis evaluated the effects of ruminant feeding type, ambient temperature (AT), and climatic region on the rumen digestibility of feeds. A dataset on nylon bag degradability parameters bearing the chemical composition of roughages, grains, leaves, stems, fruits, concentrates and diets given to animals, climate type, and AT were compiled. Data were analysed using mixed model regression and simple linear regression methodologies. Negative correlations between AT and degradability parameters were observed. Potential degradability (PD) and slowly degradable fraction (‘b’) were higher for concentrates and mixed diets compared to roughages. Intermediate feeders had slower rates of degradation (‘c’) compared to grazers. Potential degradability was highest for studies carried out in cold and temperate climates compared to tropical and arid climates. A 1 °C increase in AT decreased PD by 0.39% (roughages), 0.76% (concentrates), and 2.41% (mixed diets), with an overall decrease of 0.55% for all feed types. The “b” fraction decreased by 0.1% (roughages), 1.1% (concentrates), 2.27% (mixed diets), and 0.35% (all feed types) for every 1 °C increase in AT. Increasing AT by 1 °C increased the neutral detergent fibre content of feeds by 0.4%. In conclusion, increases in AT increased the neutral detergent fibre content of feeds, lowering PD, “b”, and “c” of dry matter in the rumen.

How do forest management and wolf space-use affect diet composition of the wolf’s main prey, the red deer versus a non-prey species, the European bison?

We analyzed the effect of forest management and wolf (Canis lupus) space-use on diet composition of red deer (Cervus elaphus) and European bison (Bison bonasus) in Białowieża Primeval Forest (BPF), Poland. The red deer is the main prey species for the wolf, whereas the European bison is rarely preyed upon. As both species behave as intermediate feeders in BPF, we expected a large overlap in their diet composition. The red deer perceives the risk of wolf predation; thus, we hypothesized that its diet would change in relation to the intensity of wolf space-use, whereas bison’s would not. We compared diet composition between two contrasting management regimes: a national park managed as a protected area (no hunting, no forestry activities, restricted tourism), and an adjacent production forest managed for timber growth and extraction, where hunting on ungulates (but not wolves) does occur. We collected dung pellets of bison and red deer along transects in low and high wolf-use areas (with distance to settlements as proxy for wolf space-use) in both management types and analyzed diet composition using DNA-metabarcoding. In the national park both the bison and red deer had higher proportions of broadleaved tree species in their diet (bison 39%, red deer 42%) than in the managed forest (bison 26%, red deer 28%). The bison diet contained a higher proportion of shrubs, and specifically Rubus in the managed forest (shrubs 29%, Rubus 31%), compared to the national park (shrubs 21%, Rubus 8%). Only in the national park, red deer ate relatively more broadleaved tree species (51%) and fewer forbs (23%) in the high wolf-use area than in the low wolf-use area (33% broadleaved trees versus 37% forbs). Bison showed a qualitatively similar shift in diet composition as red deer, but the shift was not significant and also much smaller in extent. Our results indicate that forest management shapes the diet composition of both ungulate species. In addition, red deer showed larger shifts in diet composition than bison in high versus low wolf-use areas. This suggests that in addition to habitat differences, predation risk also plays a role in shaping the red deer diet. While earlier studies in BPF illustrated that wolves affect fine-scale deer foraging behavior, this study suggests this could potentially lead to changes in diet composition. We present alternative explanations for these diet shifts and urge others to look further into predation risk as a possible driver of dietary shifts in red deer.

Fifty years of European ungulate dietary studies: a synthesis

Over recent decades, ungulate populations across Europe have undergone a rapid recovery. While this constitutes a conservation success, there is increasing concern about their impacts on shared resources with humans. Understanding ungulate food choices is crucial for predicting such impacts. Numerous studies have focused on single species or communities at narrow spatial scales. Here, we used 265 published diets from 87 European studies to investigate patterns of resource use by four common deer species (moose Alces alces, red deer Cervus elaphus, roe deer Capreolus capreolus and fallow deer Dama dama), and wild boar Sus scrofa at the continental scale. On average, deer diets separated mostly along a gradient from grass to browse. Fallow deer diets contained the most and moose diets the least amount of grass, but we also found large intraspecific variation among all deer species. Diets of roe deer, a presumed browser, frequently contained ≥ 25% grass. Wild boar diet contained grass in amounts similar to red deer but otherwise differed strongly from deer diets. All five ungulate species shifted to eating higher proportions of woody browse during winter. Habitat influenced variation in intraspecific diets, but the proportions of key forage types related to feeding type (i.e. grass for intermediate feeders red and fallow deer, and shrubs for the browsers moose and roe deer) remained fairly consisted across habitat types. In northern and central Europe, diet similarity between roe deer and red deer was highest during winter and spring and lowest during summer and autumn but remained constant across the seasons in southern Europe. We foresee that, as interspecific interactions driven by land‐use and climatic changes increase across Europe, further monitoring and testing will be needed to understand the dynamics of dietary niche partitioning among ungulates.

Resting and field metabolic rates of Awassi sheep and Baladi goats raised by Negev bedouin

AbstractSheep are grazers and goats are intermediate feeders. By employing O2 consumption and heart rate measurements, resting metabolic rate (RMR) and field metabolic rate (FMR) were determined in four male fat-tailed Awassi sheep (44.0 ± 3.94) and four male Baladi goats (35.5 ± 5.42 kg) that were co-grazing natural pasture in the Negev Desert. There were 67.7 ± 3.75 g DM/m2 of herbaceous vegetation biomass, which was rapidly becoming senescent and more fibrous. We hypothesized that FMR of these desert-adapted ruminants would be relatively low when compared to other sheep and goat breeds, as animals in arid areas tend to have low metabolic rates. Both sheep (n = 6) and goats (n = 6) foraged 71% of the allotted 11 h free-pasture period; however, sheep grazed more than goats (P &lt; 0.001); whereas goats browsed more than sheep (P &lt; 0.001). RMR was higher (P = 0.007) in sheep than in goats (529 ± 23.5 v. 474 ± 25.4 kJ/kg0.75 BW/d), but FMR did not differ between species (618 ± 55.7 v. 613 ± 115.2 kJ/kg0.75 BW/d). In addition, the cost of activities, as a proportion of FMR, did not differ between sheep and goats; FMR increased by 89 kJ/kg0.75 BW/d or 17% in sheep and by 138 kJ/kg0.75 BW/d or 29% in goats. In comparing FMRs of sheep and goats in this study with these species in other studies, differences were inconsistent and, therefore, our hypothesis was not supported.

Digesta passage in common eland (Taurotragus oryx) on a monocot or a dicot diet

The way that fluids and particles move through the forestomach of a ruminant is species-specific, and can be used to classify ruminants according to their digestive physiology into ‘moose-types’ (with little difference in fluid and small particle passage) and ‘cattle-types’ (where fluids move through the forestomach much faster than small particles). So far, ‘moose-types’ appear limited to a dietary niche of browsing, whereas ‘cattle-types’ are particularly prominent in the intermediate and grazing diet niches. However, some species, including members of the spiral-horned antelopes (the Tragelaphini), have a ‘cattle-type’ physiology but a browse-dominated diet niche. Eland (Taurotragus oryx), the largest member of the Tragelaphini, are strict browsers in the wild but have been considered intermediate feeders in the past, and can seemingly be maintained on grass diets. We quantified food intake, mean retention time (MRT) in the gastrointestinal tract and the reticulorumen (RR) of a solute, a small and a large particle marker, and diet digestibility in six eland each fed a monocot (grass hay) and a dicot (lucerne silage) forage. Food intake and digestibility was lower on the diet with higher fibre content (grass hay), with corresponding longer MRT. At the higher intakes on lucerne, the difference in MRT between small and large particles was larger, indicating a greater reliance on particle sorting and clearance under this condition of potentially limiting gut capacity. Regardless of diet or intake, the ratio of small particle and solute MRT in the RR was constant and small, at a quotient of 1.54, classifying the eland as a typical ‘moose-type’ ruminant. This finding is consistent with previous literature reports on low faecal metabolic nitrogen and high apparent protein digestibility in eland. Given the relative ease at which eland can be maintained under farm husbandry conditions, they appear ideal model ruminants to study the effects of differences in rumen physiology compared to cattle.

Response of roe deer (Capreolus capreolus) to seasonal and local changes in dietary energy content and quality

Context In terms of their nutritional physiology, roe deer have been called ‘concentrate selectors’. This implies that they select proteins in their diet and are not able to digest fibre. It is, thus, suggested that in an agricultural landscape, they are unable to digest the high fibre content of arable crops and, thus, suffer and need to be given supplementary feed. Aims Our aim was to determine the nutrient composition and energy content of the roe deer diet in an agricultural habitat compared with that in a natural forest habitat. Methods Rumen contents of 245 roe deer were collected to represent each month of the year for 3 years, weighed, and analysed by standard methods for nutrient and fibre content. Key results Roe deer in the agricultural habitat had rumen contents with significantly higher metabolisable energy (ME) concentrations, with a median of 6.2 MJ ME/kg DM, than did roe deer in the forest habitat, where the median was 5.4 MJ ME/kg DM. The mass of rumen contents in the forest habitat was, on average, 240 g higher than that in the agricultural habitat. Roe deer in the forest habitat compensate for the lower energy concentration in their natural diet by increasing their food intake. The concentration in the agricultural habitat is a result of the higher proportion of easily digestible carbohydrates in the diet. The concentration of crude protein in the rumen contents did not differ statistically between the two areas. In both habitats, the mean crude fibre concentration varied between 24% DM and 34% DM, and was significantly higher in the forest. The concentration of crude fibre selected by the roe deer is similar to the concentration of crude fibre known to be selected by red deer and fallow deer (intermediate feeders) and mouflon (a grazer) (Hofmann 1989). Conclusions The term ‘concentrate selector’ should be replaced by ‘selector’ to avoid misinterpretations. Energy shortfalls were not observed in either of the populations during the study period. Implications Supplemental feeding was not necessary to maintain the population.

Digesta passage in nondomestic ruminants: Separation mechanisms in ‘moose-type’ and ‘cattle-type’ species, and seemingly atypical browsers

Ruminants have been classified as having a ‘moose-type’ or ‘cattle-type’ digestive physiology. ‘Cattle-type’ ruminants have a clear difference in the mean retention time (MRT) of fluid vs. small particles in the reticulorumen (RR), with a high ‘selectivity factor’ (SF = MRTparticle/ MRTfluid, >1.80), and are typically grazers and intermediate feeders. ‘Moose-type’ ruminants have lower SF (<1.80), possibly because of defensive salivary proteins that constrain amounts of (high-viscosity) saliva, and are typically restricted to browsing. To further contribute to testing this physiology-diet correlation, we performed 55 individual passage measurements in 4/6 species that have/have not been investigated previously, respectively. Co-EDTA was used as a solute (fluid) and Cr-mordanted hay particles (<2 mm) as particle markers. Results are related to the percentage of grass in the natural diet taken from the literature. Moose (Alces alces, n = 4 on 4 to 5 diets each and n = 2 on a single diet, 5% grass, SF 1.46 ± 0.22) and giraffe (Giraffa camelopardalis, n = 3 on 3 to 5 diets each, 1%, 1.42 ± 0.23) as classical ‘moose-type’, and cattle (Bos taurus, n = 2, 70%, 2.04) as classical ‘cattle-type’ ruminants yielded results similar to those previously published, as did waterbuck (Kobus ellipsiprymnus, n = 5, 84%, 2.46 ± 0.49), corroborating that the SF represents, to a large extent, a species-specific characteristic. Results in oryx (Oryx leucoryx, n = 1, 75%, 2.60) and sitatunga (Tragelaphus spekii, n = 4, 68%, 1.81 ± 0.21) correspond to the concept of ‘cattle-type’ ruminants being grazers or intermediate feeders. However, European bison (Bison bonasus, n = 1, 10%, 2.74), nyala (T. angasii, n = 6, 20%, 1.95 ± 0.25), bongo (T. eurycerus, n = 3, 13%, 2.39 ± 0.54) and gerenuk (Litocranius walleri, n = 1, 0%, 2.25) appear as ‘cattle-type’ ruminants, yet have a browse-dominated diet. While the results do not challenge the view that a ‘moose-type’ digestive physiology is an adaptation to browse diets, they indicate that it may not be the only adaptation that enables ruminants to use browse. Apparently, a ‘cattle-type’ digestive physiology with a high SF does not necessarily preclude a browsing diet niche. High-SF browsers might have the benefit of an increased harvest of RR microbiota and grit removal prior to rumination; how they defend themselves against secondary plant compounds in browse remains to be investigated.

Retention of solutes and particles in the gastrointestinal tract of a grazing cervid: Père David’s deer (Elaphurus davidianus)

Ruminants are classified into three groups, according to their feeding behaviour: browsers, intermediate feeders and grazers. Corresponding to their dietary preferences, multiple morphological and physiological adaptations have been described, resulting in another classification: ‘moose-type’ and ‘cattle-type’ ruminants. Digesta retention patterns in the gastrointestinal tract (GIT) and reticulorumen (RR) are considered major criteria to distinguish these types, as cattle-type ruminants show shorter retention of fluids (measured by a solute marker) than of particles, while in moose-type ruminants, both are retained for more similar periods. To what extent these digestive types are specific to phylogenetic lineages is still unclear. We measured mean retention times (MRTs) of solutes and particles (2 and 20 mm) in the strictest grazing cervid: the Pere David’s deer (Elaphurus davidianus; n = 5; body mass = 155.0 ± 14.5 kg). The MRTs of solutes, small and large particles in the GIT were 34 ± 4, 60 ± 7 and 69 ± 9 h, respectively. The ratio of the MRT of small particles versus solutes in the RR was 2.0 ± 0.1, similar to other cattle-type ruminants. The results confirm the hypothesis that Pere David’s deer can be classified as cattle-type ruminants, corresponding to both dietary preferences and previously described morphological traits. The results complement previous findings, showing that both cattle-type and moose-type physiologies are found among bovids as well as cervids, indicating that these digestion types can be considered convergent adaptations.

Dynamic Flowsheet Model Development and Sensitivity Analysis of a Continuous Pharmaceutical Tablet Manufacturing Process Using the Wet Granulation Route

In view of growing interest and investment in continuous manufacturing, the development and utilization of mathematical model(s) of the manufacturing line is of prime importance. These models are essential for understanding the complex interplay between process-wide critical process parameters (CPPs) and critical quality attributes (CQAs) beyond the individual process operations. In this work, a flowsheet model that is an approximate representation of the ConsiGma TM -25 line for continuous tablet manufacturing, including wet granulation, is developed. The manufacturing line involves various unit operations, i.e., feeders, blenders, a twin-screw wet granulator, a fluidized bed dryer, a mill, and a tablet press. The unit operations are simulated using various modeling approaches such as data-driven models, semi-empirical models, population balance models, and mechanistic models. Intermediate feeders, blenders, and transfer lines between the units are also simulated. The continuous process is simulated using the flowsheet model thus developed and case studies are provided to demonstrate its application for dynamic simulation. Finally, the flowsheet model is used to systematically identify critical process parameters (CPPs) that affect process responses of interest using global sensitivity analysis methods. Liquid feed rate to the granulator, and air temperature and drying time in the dryer are identified as CPPs affecting the tablet properties.

Seroprevalence of Toxoplasma gondii and Neospora caninum infection in sheep, goats, and fallow deer farmed on the same area.

Toxoplasma gondii and Neospora caninum are coccidian parasites with a global distribution that cause reproductive failure and production losses in livestock. The seroprevalence of both parasite species in ruminants and Cervidae has been investigated worldwide and found to vary greatly. Studies carried out on mixed flocks with 3 ruminant species (sheep, goats, and fallow deer) living under the same conditions are excellent models for identifying any differences in the rate of infection with the 2 parasites between the animal species. Additionally, the species used in the present study differ in their feeding categories: grazers, browsers, and intermediate feeders. The aim of the study is to identify any variation in the prevalence of the 2 parasites in mixed flocks and to identify any possible relationships with food choice. The seroprevalence against T. gondii and N. caninum in 167 captive fallow deer, 64 sheep, and 39 goats were detected using commercially available ELISA. The seroprevalence for T. gondii achieved 10% in fallow deer, 21% in goats, and 47% in sheep. The seroprevalence for N. caninum achieved 13% in sheep and fallow deer and 21% in goats. Overall, 53% of the sheep, 33% of the goats, and 22% of the fallow deer were seropositive for both infections. Coinfection of T. gondii and N. caninum was detected in 6% of sheep, 8% of goats, and 2% of fallow deer. Statistical analyses of the seroprevalence levels observed between 2 parasites for each animal species revealed that only the results obtained for sheep were significant (P < 0.01). Additionally, the differences in the seroprevalence levels for T. gondii between sheep and goats and between sheep and fallow deer were statistically significant (P < 0.01). The results of the N. caninum seroprevalence levels observed among animal species were not significant. Although the variations in susceptibility to T. gondii and N. caninum infections demonstrated by the examined animals may affect the differences in seropositivity, these appear to be related to the feeding habits of the animal species. Therefore, the risk of infection by agents found close to the ground, such as coccidian oocysts, varies. Sheep as grazers are at a greater risk of infection by T. gondii than goats and fallow deer.

Dietary resource use and competition between white-tailed deer and introduced sika deer

Content Native communities of herbivores have evolved fundamental dietary niches that avoid or minimise competition; the introduction of exotic species can change dietary niches, cause overlap in resource use, and result in competition for resources. Aims We compared niche breadth, overlap in diet, and quality of diet between introduced sika deer and native white-tailed deer in Maryland, USA. We investigated these changes in free-ranging populations where both species are allopatric as well as when they are sympatric. Methods We used microhistological analysis of faecal samples to determine the percentage of resources used by sika deer and white-tailed deer, as measured between geographical areas of similar habitat quality. We compared resource use specifically by controlling for harvest pressure and resource availability, which are known to alter resource use other than the presence of an additional deer species. Key results We observed a significant resource overlap (range 63–88%) between species. In the presence of sika deer, white-tailed deer displayed an increased niche breadth (108%) and a lower diet quality (17%). Sika deer consumed the same resources that comprised 78% of white-tailed deer diet. Unlike other native ungulates that have dietary overlap with white-tailed deer, sika deer is neither temporally nor geographically segregated in habitat use. Conclusions Resource overlap and changes in niche breadth and diet quality during sympatry strongly denote dietary competition between sika deer and white-tailed deer. This competition results in white-tailed deer altering the dietary selection, thereby consuming lower-quality forage. Implications White-tailed deer are concentrate selectors and require higher diet quality than do sika deer, which can tolerate diets higher in fibre, consistent with their classification as intermediate feeders. A decrease in the nutritional quality of resources used by white-tailed deer could contribute to the decline of white-tailed deer over time and allow the continued spread of sika deer.

Variation of natural diet of free ranging mouflon affects their ruminal protozoa composition

The mouflon’s traditional classification as a grazer has recently been questioned, therefore new insight into the species’ feeding and digestion is needed. The presence and share of different ciliate genera in the rumen may contribute to an understanding of a species’ feeding physiology, therefore we analysed the composition of mouflon rumen ciliates and correlated their density with the percentage of different food types eaten by the animals. We found that the dominant ciliates were Entodinium spp., with a small proportion of Anoplodinium denticulatum, Eudiplodinium maggii, Epidinium ecaudatum caudatum and Dasytricha ruminantium. The main food types taken by the animals were deciduous tree leaves, grass and bramble. The density of ciliates from the Entodinium genus rose with an increase in deciduous leaves in the diet and fell with an increase of graminoids in the diet. The density of ciliates from the Anoplodinium and Eudiplodinium sub-genera increased with a rise in tree shoots and was reduced with a rise of deciduous leaves in the diet. These results confirm that the protozoal fauna vary with current food composition in intermediate feeders.

Are Bison Intermediate Feeders? Unveiling Summer Diet Selection at the Northern Fringe of Historical Distribution

Bison (Bison bison) were historically distributed throughout North America with the northern edge of the distribution occurring in north-central Manitoba and surrounding provinces. Despite bison occupying the boreal zone of North America, little is known of their forage selection patterns of herbaceous plant material when occupying pastures within a densely forested aspen ecosystem. In 2015 we initiated a study to examine forage selection patterns for bison among and within summer months (June–August). We hypothesized that vegetative composition of bison diets would be consistent with availability, would shift with forage availability, and would predominately consist of grass and sedge species. We opportunistically collected adult female bison fecal samples (N = 99) and identified forage composition using the DNA barcoding method. We estimated availability of forage to the lowest taxonomical level possible using a modified Daubenmire frame. Overall, bison diets were composed of 44.3% grass, 37.7% forb, 16.3% browse, and < 2% sedge and rush. Forage availability comprised 51.2% grass, 28.3% forb, 11.0% sedge, and 7.6% rush. All analyses indicated that use and availability for grass, forb, sedge, and rush differed (P ≤ 0.05) throughout the summer. Grass and forbs were important dietary components for bison, comprising > 80% of bison diets. However, bison selected for these two dietary components independently as the summer progressed. Our results indicate that these bison consume a large portion (~54.0%) of low-cellulose, high cell-soluble forages to meet their dietary needs. This suggests that bison may be or become intermediate foragers and are more like elk (Cervus elapus) than domestic cattle or sheep when inhabiting forested systems at the northern edge of their historical distribution. Herd managers and biologists should be cognizant of the importance of eudicots for bison and adopt a management plan that promotes a spatially heterogenous vegetative schematic.

Gross Anatomy of the Stomach of the Dorcas Gazelle (Gazella Dorcas, Linnaeus, 1758)

The macroscopic anatomy of the stomach in four adult dorcas gazelle was described. Four adult, two male and two female dorcas gazelle (Gazella dorcas) of the Frigya Zoological Park, Enfidha, Tunisie, were used in this study. The ruminal papillae were distributed unequally in the rumen, and were larger and more abundant within the atrium and in the two saccus cecus. The papillae were absent in dorsal part of the dorsal sac. The ruminal pillars had no papillae. The cellulae reticuli were divided and contained secondary and tertiary crests. The curvatura omasi measured 12.1±0.1 cm. A comparison with literature data for sand gazelles (Gazella subgutturosa marica) emphasises that differences between closely related species that fill similar niches cannot be expected to follow a clear pattern, but yield an inhomogenous picture, with some measurements more tending towards a specific feeding type in the one, and some other measurements tending more towards that feeding type in the other species.We concluded that the stomach morphology of the dorcas gazelle indicates the‘cattle-type’ morphophysiology representative for intermediate feeders.

Morphology is not Destiny: Discrepancy between Form, Function and Dietary Adaptation in Bovid Cheek Teeth

Mammal teeth have evolved morphologies that allow for the efficient mechanical processing of different foods, therefore increasing dietary energy uptake for maintenance of high metabolic demands. However, individuals masticate foods with biomechanical properties at odds with the optimal function of a given tooth morphology. Here, we investigate tooth form and function using two quantitative 3D methods at different scales on the same individuals of nine bovid species. Dental topometry quantifies the gross morphology, and therefore, reflects evolutionary adaptive patterns. Surface texture analysis infers mechanical occlusal events, which reflect the actual tooth function, and is free from the influence of morphology. We found that tough foods can be satisfactorily exploited by grazing species with enamel ridge morphologies not more complex than those found in intermediate feeders and browsers. Thus, the evolution of enamel complexity is likely determined by a balance between adaptation and constraints. Wider enamel ridges seem to be a common functional trait in bovids to compensate for severe wear from abrasive foods and/or chipping from hard foods. Our results demonstrate that supposedly essential functional adaptations in tooth morphology may not be required to process food efficiently. This emphasizes the large plasticity between “optimal” morphology and the potential function of the tooth, and underscores the need to appreciate (apparently) maladaptive structures in mammalian evolution as nevertheless effective functioning units.

Do body size, diet type or residence time explain habitat use in a vertebrate herbivore community?

Many theories attempt to explain patterns of community organisation among large herbivores. We explored the role of body size, diet type and residence time on habitat use in a community comprising four metatherians (western grey kangaroo, Macropus fuliginosus; eastern grey kangaroo, M. giganteus; red-necked wallaby, Notamacropus rufogriseus; swamp wallaby, Wallabia bicolor) and two eutherians (red deer, Cervus elaphus; European rabbit, Oryctolagus cuniculus) in south-eastern Australia. We used camera traps to estimate habitat occupancy, quantified habitat specialisation using relative entropy, and ran regressions using percentage grass consumed, log(mass) and log(time at site) as predictor variables and relative entropy as the response. If body size influenced habitat use, we predicted smaller species would occupy fewer habitats. If diet type influenced habitat use, we predicted intermediate feeders would use more habitats. If the time that a species had been present at a site predicted community organisation, newer species would use more habitats. None of these theories explained habitat use in our community. Red deer used a narrower range of habitats than expected, perhaps due to the poor suitability of habitats available in the Grampians. While interactions between our hypotheses are likely to be important, the body size model deserves further attention in this community.

From steps to home range formation: species‐specific movement upscaling among sympatric ungulates

Summary Animals move to interact with the environment in order to find food resources and cover. Intrinsic characteristics affecting feeding and antipredatory strategies likely shape variation in movement patterns and home range formation between individuals, populations and species. Browsing herbivores selectively forage on patchily distributed resources in areas with more canopy cover, whereas mixed feeders and grazers feed on more open grasslands and tend to aggregate as an antipredatory strategy. We therefore predicted that at small temporal scales, browsers will show greater net displacements (i.e. typical of searching patterns) than mixed feeders or grazers; but at larger temporal scales, we expect the opposite pattern, since gregarious species will need to use larger areas to feed the whole herd. We also predicted that the feeding/antipredatory strategy will determine the behavioural responses to other environmental factors. To test this, we compared spatial movement patterns at multiple scales (from 20‐min intervals to annual home ranges) of three sympatric, similar‐sized, alpine ungulates which differ in their feeding/antipredatory strategy: roe deer (solitary browsers), mouflon (gregarious grazers) and chamois (intermediate feeders in smaller groups). We used location data from GPS‐collared females of the three species in the French Alps. As predicted, we found that multi‐scale spatial patterns depended on the feeding/antipredatory strategy. Browsers foraged within smaller range areas, searching back and forth. Mixed feeders and, especially, grazers covered larger areas, presumably to satisfy herd needs. The feeding/antipredatory strategies also determined the interspecific variability in behavioural responses to factors such as maternal status, weather, habitat type or human disturbance, supporting our hypothesis. Exploring interspecific variability, we showed how movement behaviour and home range formation vary substantially, even among species within the same guild. This mechanism might be important to maintain intra‐guild multi‐species associations and increase biodiversity, through contributing to niche segregation and, thus, coexistence.