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Article

Trophic Relationships Between Thinocorus orbignyanus (Charadriiformes: Thinocoridae), Lepus europeaus (Lagomorpha: Leporidae), and Equus ferus caballus (Perissodactyla: Equidae) in High-Mountain Grasslands During the Summer Season

by
Giorgio Castellaro Galdames
*,
Carla Orellana Mardones
,
Juan Pablo Escanilla Cruzat
and
Claudia Navarro Espinosa
Department of Animal Production, Faculty of Agronomic and Environmental Sciences, University of Chile, Santiago 8820808, Chile
*
Author to whom correspondence should be addressed.
Ecologies 2025, 6(3), 57; https://doi.org/10.3390/ecologies6030057
Submission received: 19 May 2025 / Revised: 30 July 2025 / Accepted: 8 August 2025 / Published: 15 August 2025
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Abstract

With the purpose of understanding the trophic relationships between three herbivores that use humid high-mountain grassland and evaluating a possible interspecific competition between them and depending on the importance of the hydromorphic vegetation formations of high-mountain areas, relations were established between the attributes of these grasslands and the botanical composition of the diet of grey-breasted seedsnipe (Thinocorus orbignyianus), brown hares (Lepus europaeus), and horses (Equus ferus caballus). For two summer seasons, the botanical composition of the grassland and dry matter availability were assessed. In parallel, the botanical composition of the diets of the three herbivores was estimated through fecal microhistology. Based on the botanical composition data for both the grasslands and herbivores’ diets, their relative diversity was estimated. The Pianka index was established among the three herbivores. Hares showed greater dietary diversity (J) than horses and grey-breasted seedsnipes, factors that were negatively correlated in all three cases with the vegetation diversity patch. The same response amplitude was found when analyzing the food web. The dietary diversity for all species showed no relation to the dry matter productivity of the vegetable patches. Through analyzing the correlation of the abundance of two species of Cyperaceae in the grassland with the presence of the same in the diet of herbivores, we found a negative relationship between the abundance of Carex sp. and grey-breasted seedsnipe diet, and a positive relationship between the Eleocharis pseudoalbibracteata species abundance and frequency in the diet of hares and horses. About the group of species content of graminoids in the diet, a dietary overlap of 30% was determined in the animal species assessed; depending on that, it could identify the existence of interspecific competition between herbivores, which would be conditioned by the response of individuals to the environment. However, and according to the magnitude of the dietary overlap, a low probability of interspecific trophic competition among the studied herbivore species can be expected, which enables the use of the highland wet grassland habitat in sympatry.

1. Introduction

The high-Andean grasslands of Chile are distributed from Atacama to the Araucania region in high-altitude areas of the Andes Mountains. These ecosystems are considered natural systems or sometimes altered by anthropic activities, whose forage production can be utilized from mid-spring to summer [1]. The use of these high-altitude wetlands for seasonal livestock grazing involves the coexistence of domestic, introduced, and wild herbivorous vertebrates. Competitive interactions among these species are expected to intensify during these periods when food resources are scarce [2]. However, in Chile, there are few studies on this type of interaction and its intensity in these environments. Among the wild herbivores using these ecosystems are guanacos (Lama guanicoe Müller, 1776), hares (Lepus europaeus Pallas, 1778), Andean geese (Chloephaga melanoptera Eyton, 1838), and grey-breasted seedsnipes (Thinocorus orbignyianus Geoffroy Saint-Hilaire, I; Lesson, RP, 1831). This last species of bird (Figure 1) is a charadriiform of the Thinocoridae family that lives in the southwestern part of South America, and in Chile, it is found especially in high-altitude wetland habitats, over 3500 m, and its conservation status is classified as lower risk [3] (IUCN, 2025. https://www.iucnredlist.org/species/22693042/93380458, accessed on 7 August 2025).
The hares, Andean geese, and grey-breasted seedsnipes primarily utilize hydromorphic grasslands (wet grasslands), as do domestic livestock—mainly horses (Equus ferus caballus Linnaeus, 1758)—which occupy these areas during the summer months [5]. In European wet grassland environments, a high proportion of grasses and graminoids have been reported in the diet of horses [6,7], which could occur in the grasslands where we conducted our research. The above situation could represent potential competition with wild herbivores, both native and introduced, that make use of this natural resource. In turn, the European hare, which was introduced to Latin America at the end of the 19th century, is considered a potential competitor, especially for native rodents and other herbivores, such as some birds, such as grey-breasted seedsnipes [8]. The situation described above could constitute a case of potential trophic competition between native, introduced, and domestic herbivores, an aspect that has not been studied in detail in this type of ecosystem, which is why it is one of the main reasons for our research.
Given this, it is evident that forage resources are shared by both resident and occasional herbivores, a situation where a high trophic niche overlap among studied herbivores has been identified [9,10]. This phenomenon depends on the type and abundance of forage resources, which, in high-mountain environments, vary according to soil moisture availability. This is influenced by three combined factors: topographic conditions, wind exposure, and winter snow cover. These gradients determine the formation of a mosaic of plant communities [11]. The ability of herbivores to modify dietary components is based on the temporal abundance of plant species in a grassland patch (understanding the latter as a discrete and homogeneous area of vegetation, but it is very different from the vegetation that surrounds it [12]), which distinguishes animal species that are efficient in resource use [13]. Thus, the goal is to establish relationships between diet and foraging area attributes as a first step toward understanding interactions in these environments [14]. These findings could facilitate inferences about niche overlaps or differentiation in at least one dimension of the trophic niche [15], enabling the coexistence of species competing for the same resource in a non-random manner, primarily based on nutritional aspects [16,17].

2. Materials and Methods

2.1. Study Area

The study was conducted at eight high-altitude wetland sites in the southern Andes of Cuncumén, Salamanca, in the Coquimbo Region of Chile (31°52′–32°02′ S; 70°19′–70°26′ W; 3025–3729 m above sea level) (Figure 2).
The climate in the area corresponds to the steppe province with a very cold dry summer or mountain summer ecoregion, which, according to Köeppen [18], is classified as a BSsk climatic type. The hydric azonally distributed grasslands (“high-altitude wet grasslands”), which develop on hydromorphic soils, are the main source of high-quality forage for herbivores. These grasslands are dominated by graminoid species (families Cyperaceae and Juncaceae), notably Eleocharis pseudoalbibracteata S. González & Guagl. and Carex gayana E. Desv, 1854. These species are considered key components of this type of grassland [2]. The bromatological analysis of both species is presented in Table 1:

2.2. Botanical Composition and Dry Matter Production in the Grassland

Evaluations of the botanical composition of hydromorphic grasslands were carried out in March of 2011 and 2012, a period during which the grasslands still show a high growth rate; 100 points spaced 20 cm apart on 31 linear transects of 20 m length, arranged in eight sectors representative of this type of grassland, were evaluated. These were determined from grassland maps in previous studies carried out in the area [5]. In each transect, the modified Point Quadrat method was used, which allows determining the relative participation of the different plant species in the community [19,20]. At each site in the plain and associated with each transect, dry matter (DM) production was estimated, which was measured by harvesting 31 exclusion plots of 3 × 3 m and 7.29 m2 of usable area. At the beginning of the growing season, the remaining DM from the previous season was removed from each of the plots, and at the end of the season, the phytomass accumulated during the growing season was harvested, leaving a residue of approximately 5 cm to allow for regrowth after cutting [21]. This phytomass was subsequently dried in a forced-air oven at 60 °C for 48 h, to express the forage production of the plot in terms of 92% DM (kg ha−1) [22].

2.3. Evenness of Plant Species in the Grassland

To estimate the evenness of plant species in the wet grasslands, their botanical composition data were used. With this information and in each evaluated line, the Shannon–Wiener diversity index was calculated as follows [23]:
H = − ∑ i = 1 n p i · L o g 2 ( p i )  
This index was expressed as relative diversity or evenness (Jp) [24], according to the following equations:
J p = H H m a x
H m a x = L o g 2 n
In the previous equations, pi is the proportion of i species in the grassland, and n is the number of species in it. Hmax represents the value H would have if all species found in the grassland had the same frequency.

2.4. Evenness of Hervibore’s Diets

In each wet grassland site, fresh feces samples were collected from horses (E. ferus caballus), hares (L. europaeus), and grey-breasted seedsnipes (T. orbignyianus). The samples consisted of a set of 15 to 20 fresh fecal droppings from each animal species, obtained through a “cross-country” route across the wet grassland site. After collecting the samples, these were dehydrated in a forced-air oven at 60 °C for 48 h and stored in airtight jars until further processing. The botanical composition of the diet was determined through microhistological analysis of the feces [25,26,27]. This method is based on the microscopic identification of plant epidermal fragments, mainly from leaves and stems, that have characteristics allowing for the differentiation of plant species [28,29].
The results of the microscopic reading were expressed as the relative frequency for each plant species, which is considered a good estimator of dry weight in mixtures of known composition [30]. Subsequently, this frequency was converted into density using the tables of Fracker and Brischle [25,31]. The identified plant species were grouped into five categories: annual grasses (Poaceae), perennial grasses, graminoids (Cyperaceae and Juncaceae), dicotyledonous herbs, and shrub species.
With the botanical composition of each herbivore’s diet established, its relative evenness (Jd) was determined using the same equations employed to calculate the evenness of the grassland (Equations (1)–(3)). The Jd index ranges between 0 (very low dietary evenness) and 1 (all species in the diet have the same abundance). Generally, when Jd values are below 0.3, it indicates highly specialized diets, while values above 0.6 suggest a generalist diet [32,33].
Finally, to determine the trophic niche overlap among the three herbivores studied, in terms of the relative contribution of graminoid species in the diet, Pianka’s index (O) [34] was calculated using the following equation:
O = ∑ p i · q i ∑ p i 2 · ∑ q i 2
where pi corresponds to the frequency of species i in the diet of herbivore A, and qi corresponds to the frequency of the same species i in the diet of herbivore B. Like the evenness index, this variable ranges from 0 to 1. Values equal to or greater than 0.7 indicate a high dietary overlap.

2.5. Statistical Analysis

As this study was observational, an “a priori” experimental design was not carried out. Nevertheless, an analysis of variance (ANOVA) was carried out on the dietary evenness results (Jd) and trophic niche range (Best), with a totally randomized design, with its correspondent assumptions considering the herbivore species as the only source for variation [35]. The differences among herbivores were determined through the Tukey test with a 5% level of significance. The association among the assessed variables was determined through the estimation of the Pearson correlation with a 5% level of significance and a regression analysis. All the statistical analysis was performed using the STATGRAPHICS Centurion XVI® version 16.1.03 software (Statgraphics Technologies, Inc., The Plains, VA, USA).

3. Results

3.1. Evenness of the Hervivore’s Diet

The relative evenness index (Jd), which accounts for the similarity in the proportions of plant species that make up the diet, observed a significant effect attributed to the type of herbivore (p = 0.0006), with the diets of hares and horses being the most diverse, with values of 0.759 ± 0.028 and 0.750 ± 0.026, respectively. The above values were statistically like each other, differing significantly from those found in the part-ridge diet in which Jd obtained a significantly lower value (0.593 ± 0.032) (Figure 3).

3.2. Diet Evenness and Its Relationship with Grassland Patch Evenness and Dry Matter Production

The evenness of the grey-breasted seedsnipes diet was negatively correlated with the evenness of the patch used as a food resource (r = − 0.708; p = 0.022), while in the case of hares, this correlation was lower and of lesser significance (r = − 0.528; p = 0.064) (Figure 4). In the case of equines, this correlation was even lower, lacking statistical significance (r = −0.212; p = 0.449).
The relationships presented in the previous figure would indicate that the evenness of the pasture would contribute to shaping the evenness of the diet only in the case of grey-breasted seedsnipes.
No linear correlation was found between the evenness of the diet of equines and hares with the dry matter production of the patch; however, in the case of the dietary evenness of grey-breasted seedsnipes, it observed a quadratic trend, which turned out to be significant (p = 0.05) and with an R2 of 0.713 (Figure 5).

3.3. Presence of Indicator Plant Species in the Diet

The grassland indicator or key plant species, which are ”forage species whose use serve as indicators to the degree of use of associated species” [26], in this case the graminoids C. gayana and E. pseudoalbibracteata, contributed to the botanical composition of the grasslands with percentages that varied between 48 and 59%, depending on the grassland site. Previous work carried out by our team has determined contributions between 20 and 25%, respectively, for the aforementioned species [5]. These two species together were present in the diet of the grey-breasted seedsnipe, hares, and horses in a percentage of 44.6 ± 7.4, 35.8 ± 6.5, and 43.8 ± 6.0%, respectively, figures that were not statistically different from each other (p = 0.579). Given the importance of these species in the diet of the herbivores studied, the percentage contribution of the two “indicator” species in the diet was correlated with the percentage contribution of the same in each grassland patch. In the case of the grey-breasted seedsnipe, the result was negative (r = −0.758; p = 0.011). Thus, as the percentage of presence of this plant species in the plain increases, its content in the diet decreases, a relationship to which a negative exponential model could be adjusted (Figure 6).
For both hares and horses, this correlation was low and lacking statistical significance (Figure 7A,B).
When relating the content of E. pseudoalbibracteata present in the diet of the grey-breasted seedsnipe with the content of this graminoid in the wet grassland, an exponential relationship was found (Figure 8A), suggesting a slow increase in the contribution of E. pseudoalbibracteata in the diet of this bird when the proportion of this species in the grassland is low, but when this proportion exceeds 30%, the dietary contribution increases rapidly. In contrast, in the case of hares and equines, this relationship was linear (r = 0.578; p = 0.039; r = 0.737; p = 0.003, respectively) (Figure 8B,C). The increase in the dietary intake of this graminoid in both herbivores was less than proportional, which is reflected in the magnitude of the slope of the regression lines, which in both cases was less than unity, especially in the case of hares.

3.4. Dietary Overlap

Based on the relative importance of graminoids in the diet of the three herbivores, the dietary overlap for this item was determined using Pianka’s index, with the results shown in Table 2. The magnitude of the overlap reached more than one-third for all analyzed species, tending to be higher between L. europaeus and T. orbignyianus.

4. Discussion

It is complex to assess interspecific competition in vertebrates [36], given the difficulty of controlling all the factors that would influence such interactions. Currently, there are no studies that clearly demonstrate the trophic competition that might exist among these three species; however, the degree of similarity in the botanical composition of their diets could provide indications of the existence of this phenomenon [3,7,30]. The evenness (Jd) (homogeneity) of the diets of the three herbivores is considered medium to high, which could indicate that they are species with generalist feeding strategies [15], especially in the case of L. europaeus and E. caballus. Studies conducted on rodents (Dolichotis patagonum) in the Argentinean Patagonia corroborate that such species would be generalists in their food selection [37]. Meanwhile, for equines, it is well known that their grazing behavior allows for equitable selection of the plant species that make up their diet [38]. Castellaro et al. [5] reported a dietary evenness index of around 0.77 for horses in this same environment, which could remain relatively constant, as observed by Reuss et al. [39] in donkeys (Equus africanus asinus L., 1758). T. orbignyianus exhibited the least diverse (most homogeneous) diet, tending to consume a greater proportion of a specific plant species at the expense of others. Korzun et al. [40] conducted a study on the anatomy of birds of the genus Thinocorus, describing the morphology of their skulls, which could explain the dietary preferences these animals exhibit in qualitative terms. However, most of these birds exhibit marked dietary preferences, which have been better studied in granivorous and frugivorous types [41]. Orellana et al. [42] found Jd values ranging from 0.49 to 0.70 in the diets of wild geese (C. melanoptera) in high-Andean environments, with graminoid species dominating their diets. The values obtained for dietary breadth indicate that hares and equines have a broader range in this attribute compared to the grey-breasted seedsnipe, a pattern like that found in the study by Rodríguez and Dacar [37] on D. patagonum. Horses showed dietary evenness like that of hares, but different from that observed in the grey-breasted seedsnipe, which could be due to lower ease in harvesting food based on bite size. While this allows them to select the grazing area, it limits their ability to separate one species from the others growing alongside it. Each herbivore species has anatomical adaptations that allow them to better select and obtain specific parts of the plant to consume, as well as physiological adaptations that enable them to process these plants effectively [43,44]. The narrower trophic niche breadth of T. orbignyianus, reflected in a lower relative evenness index, suggests greater specificity in the selection of forage resources [45], tending toward less generalist dietary habits [27], though not reaching the level of specialization. This behavior could be due to morphophysiological differences among herbivores [13,44], as the bird’s oral apparatus would allow for more rigorous food selection.
As the evenness of plant communities in the hydromorphic grassland (Jp) increased, the dietary evenness in the grey-breasted seedsnipe and hares decreased. This observation could be explained by the evenness in species frequency within the wet grassland, which would increase the animals’ ability to select specific plant species. The animals tend to focus on those plant species that provide the greatest nutritional benefit [45]. In the case of horses, this behavior was not observed, as their Jd was unaffected by the increase in plant species evenness in the grassland.
It was not possible to establish a relationship between dietary evenness and the availability of plant dry matter, suggesting that an increase in grassland productivity does not necessarily indicate greater species richness [26].
It is evident that, both spatially and temporally, the three evaluated herbivores utilize the same resource, as confirmed by the significant presence of graminoid species in their diets, with a minimum value of 30%. Abrams [46] suggests that interaction among herbivores can be demonstrated if at least some dimensions of their ecological niches overlap, necessitating an evaluation of resource dynamics in relation to each feeding strategy. One species identified as an “indicator” was C. gayana, whose frequency decreased in the diet of the grey-breasted seedsnipe as the abundance of this plant species increased in the patch. This pattern suggests that consumption of this resource may be modulated by anti-apostatic selection [47], wherein consumers avoid more abundant resources in favor of less common ones. Such behavior is rare in birds but has been documented in some wild marine species [48]. In contrast, no relationship was found between the frequency of C. gayana in the diets of the other two herbivores and its abundance in the grassland. Evaluating the dietary preferences of horses and hares, and how these change in response to resource availability, is crucial due to the potential impact of species selection on the ecosystem [49]. Studies on the effects of introduced ungulates in New Zealand have concluded that herbivory can lead to a reduction in floristic evenness, attributable to the lack of defenses in certain plant species [50].
An increase in the abundance of E. pseudoalbibracteata corresponded with a higher presence of this species in the diets of all three evaluated herbivores, particularly in the grey-breasted seedsnipe and horses. This suggests that the selection of this resource could be characterized as apostatic [51], where consumers prefer more common resources. The consumption of this species in relation to its abundance may also explain its high frequency in the evaluated grasslands. Nutritionally, this plant species differs from C. gayana, especially in its cell wall content (NDF), which could be significant for these herbivores. This is particularly relevant for the grey-breasted seedsnipe, which generally may have a lower capacity to digest fibrous plant material compared to lagomorphs and equines [44].
Based on the provided data and the estimation of dietary overlap using Pianka’s index, a potential competition between hares and equines can be inferred, with a trophic niche overlap associated with graminoid species of approximately 30%. This figure is lower than that reported for rabbits and cattle in the Argentinean pampas, and lower than that determined between these same herbivores by Castellaro et al. [5] in this environment. Studies carried out on viscachas (Lagostomus maximus, Desmarest, 1817), lagomorphs, and domestic goats show that introduced herbivores have a greater competitive capacity compared to native ones [52], an aspect that could represent a threat to the latter. The interaction between the grey-breasted seedsnipe and horses over the same resource is around 32%, while the overlap between hares and grey-breasted seedsnipes reaches nearly 40%. However, given the magnitude of these dietary overlaps, the potential trophic competition among the three studied herbivores would be considered medium to low, which would allow their coexistence in this ecosystem, as has been determined in native and non-native herbivores in the arid ecosystems of Argentina [26,52]. It is important to note that the degree of trophic competition could be conditioned not only by the compositional aspect of diet, since for organisms of the same trophic level, the use of common resources with limited availability would also result in competitive interactions [53]. In addition to the above, the effect of body size, the growth rate of sympatric populations, landscape variability, forage quality, and mass could be added [54,55].

5. Conclusions

According to our results, the trophic niche breadth suggests that the diets of the three studied herbivores are composed of a limited number of plant species, particularly in the case of the grey-breasted seedsnipe. However, these diets are relatively balanced, a trait more evident in equines and hares, which also exhibit more pronounced generalist feeding habits. Only in the case of the grey-breasted seedsnipe was an association observed between dietary evenness and the evenness of plant species in the grassland patch. This indicates that, for this bird, as the evenness in the frequency of plant species in the grassland increases, the likelihood of selecting specific plant species also increases, resulting in a decrease in the evenness of its diet. The availability of dry matter in the grassland does not influence the herbivores’ ability to select more diverse diets. An exception may be the grey-breasted seedsnipe, for which a quadratic trend was observed—dietary evenness tends to be higher at very low or very high relative values of DM availability. Among the key species in the hydromorphic grassland, only E. pseudoalbibracteata was relevant as a modulator of diet composition in the three studied herbivores, showing a positive association; as its abundance in the pasture increases, its contribution to the herbivores’ diet also increases, playing a significant nutritional role in maintaining physiological processes. In the case of C. gayana, its dietary contribution becomes important when its presence in the pasture is low, and this is only relevant for the grey-breasted seedsnipe. Based on the feeding strategy that results in low dietary overlap, a low probability of interspecific trophic competition among the studied herbivore species can be expected, which enables the use of the highland wet grassland habitat in sympatry.

Author Contributions

Conceptualization, methodology, data analysis, and manuscript draft by G.C.G., C.O.M., J.P.E.C. and C.N.E.; execution of field experiments by G.C.G., C.O.M. and J.P.E.C. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the Project “CS-1650 MLP-CEA—Characterization Study of the Wetlands of the South Cordillera of Cuncumén”. Antofagasta Minerals Los Pelambres-CEA S.A.

Institutional Review Board Statement

Ethical review and approval for this study was waived, due to the stool samples used in the dietary analysis by microhistology being collected from the ground surface, without requiring any manipulation of the animals.

Data Availability Statement

The data presented in this study are available on request from the corresponding author.

Conflicts of Interest

The authors declare no conflicts of interest.

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Ecologies 06 00057 g001
Figure 1. Thinocorus orbignyianus. Source: Birds of the World [4]. © Michel Gutierrez (Macaulay Library eBird).
Figure 1. Thinocorus orbignyianus. Source: Birds of the World [4]. © Michel Gutierrez (Macaulay Library eBird).
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Figure 2. Location of the area where the study was carried out.
Figure 2. Location of the area where the study was carried out.
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Figure 3. Relative evenness indices (Jd) for Thinocorum orbignyianus, Lepus europaeus, and Equus ferus caballus, in high-mountain hydromorphic grasslands. The bar around the mean value indicates ±+/− one standard error. Different letters above the bars indicate significant difference at Tukey’s test at 5%.
Figure 3. Relative evenness indices (Jd) for Thinocorum orbignyianus, Lepus europaeus, and Equus ferus caballus, in high-mountain hydromorphic grasslands. The bar around the mean value indicates ±+/− one standard error. Different letters above the bars indicate significant difference at Tukey’s test at 5%.
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Figure 4. Relationship between diet evenness index (Jd) and grassland patch evenness (Jp) for (A) Thinocorum orbignyianus, (B) Lepus europaeus, and (C) Equus ferus caballus, in high-mountain hydromorphic grasslands. (o: field data; ---- linear fit).
Figure 4. Relationship between diet evenness index (Jd) and grassland patch evenness (Jp) for (A) Thinocorum orbignyianus, (B) Lepus europaeus, and (C) Equus ferus caballus, in high-mountain hydromorphic grasslands. (o: field data; ---- linear fit).
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Figure 5. Relationship between the diet evenness index of Thinocorum orbignyianus (Jd) and the dry matter production of the grassland patch (kg DM/ha) in high-mountain hydromorphic grasslands. (o: field data; ---- quadratic fit).
Figure 5. Relationship between the diet evenness index of Thinocorum orbignyianus (Jd) and the dry matter production of the grassland patch (kg DM/ha) in high-mountain hydromorphic grasslands. (o: field data; ---- quadratic fit).
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Figure 6. Relationship between the abundance of Carex gayana in the diet of Thinocorum orbignyianus (%) and the abundance of Carex gayana in the grassland patch (%), in high-mountain hydromorphic grasslands. (o: field data; ---- exponential fit).
Figure 6. Relationship between the abundance of Carex gayana in the diet of Thinocorum orbignyianus (%) and the abundance of Carex gayana in the grassland patch (%), in high-mountain hydromorphic grasslands. (o: field data; ---- exponential fit).
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Figure 7. Relationship between abundance of Carex gayana in the diet (%) and abundance of C. gayana in the grassland patch (%), for (A) Lepus europaeus and (B) Equus ferus caballus, in high-mountain hydromorphic grasslands. (o: experimental data).
Figure 7. Relationship between abundance of Carex gayana in the diet (%) and abundance of C. gayana in the grassland patch (%), for (A) Lepus europaeus and (B) Equus ferus caballus, in high-mountain hydromorphic grasslands. (o: experimental data).
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Figure 8. Relationship between the abundance of Eleocharis pseudoalbibracteata in the diet (%) and the abundance of E. pseudoalbibracteata in the grassland patch (%), for (A) Thinocorus orbignyianus, (B) Lepus europaeus, and (C) Equus ferus caballus, in high-altitude hydromorphic grasslands. (o: field data; ---- exponential or linear fit).
Figure 8. Relationship between the abundance of Eleocharis pseudoalbibracteata in the diet (%) and the abundance of E. pseudoalbibracteata in the grassland patch (%), for (A) Thinocorus orbignyianus, (B) Lepus europaeus, and (C) Equus ferus caballus, in high-altitude hydromorphic grasslands. (o: field data; ---- exponential or linear fit).
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Table 1. Bromatological analysis of the plant species Carex gayana and Eleocharis pseudoalbibracteata, which provide details of the content of neutral detergent fiber (NDF, %), acid detergent fiber (ADF, %), crude protein (CP, %), dry matter digestibility (DMD, %), and metabolizable energy concentration (ME, MJ kg−1).
Table 1. Bromatological analysis of the plant species Carex gayana and Eleocharis pseudoalbibracteata, which provide details of the content of neutral detergent fiber (NDF, %), acid detergent fiber (ADF, %), crude protein (CP, %), dry matter digestibility (DMD, %), and metabolizable energy concentration (ME, MJ kg−1).
Plant SpeciesNDF
(%)		ADF
(%)		CP
(%)		DMD
(%)		ME
(MJ kg−1)
C. gayana55.8926.528.8968.2410.03
E. pseudoalbibracteata50.4830.708.6364.989.47
Source: Animal Nutrition Laboratory, Faculty of Agronomic and Environmental Sciences, University of Chile.
Table 2. Pianka’s dietary overlap index (0–1) for graminoid functional types among Thinocorus orbignyianus, Lepus europaeus, and Equus ferus caballus in high-altitude hydromorphic grasslands.
Table 2. Pianka’s dietary overlap index (0–1) for graminoid functional types among Thinocorus orbignyianus, Lepus europaeus, and Equus ferus caballus in high-altitude hydromorphic grasslands.
Herbivore SpeciesThinocorum orbignyianusLepus europaeusEquus ferus caballus
Thinocorus orbignyianus---0.3970.328
Lepus europaeus0.397---0.303
Equus ferus caballus0.3280.303---
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Castellaro Galdames, G.; Orellana Mardones, C.; Escanilla Cruzat, J.P.; Navarro Espinosa, C. Trophic Relationships Between Thinocorus orbignyanus (Charadriiformes: Thinocoridae), Lepus europeaus (Lagomorpha: Leporidae), and Equus ferus caballus (Perissodactyla: Equidae) in High-Mountain Grasslands During the Summer Season. Ecologies 2025, 6, 57. https://doi.org/10.3390/ecologies6030057

AMA Style

Castellaro Galdames G, Orellana Mardones C, Escanilla Cruzat JP, Navarro Espinosa C. Trophic Relationships Between Thinocorus orbignyanus (Charadriiformes: Thinocoridae), Lepus europeaus (Lagomorpha: Leporidae), and Equus ferus caballus (Perissodactyla: Equidae) in High-Mountain Grasslands During the Summer Season. Ecologies. 2025; 6(3):57. https://doi.org/10.3390/ecologies6030057

Chicago/Turabian Style

Castellaro Galdames, Giorgio, Carla Orellana Mardones, Juan Pablo Escanilla Cruzat, and Claudia Navarro Espinosa. 2025. "Trophic Relationships Between Thinocorus orbignyanus (Charadriiformes: Thinocoridae), Lepus europeaus (Lagomorpha: Leporidae), and Equus ferus caballus (Perissodactyla: Equidae) in High-Mountain Grasslands During the Summer Season" Ecologies 6, no. 3: 57. https://doi.org/10.3390/ecologies6030057

APA Style

Castellaro Galdames, G., Orellana Mardones, C., Escanilla Cruzat, J. P., & Navarro Espinosa, C. (2025). Trophic Relationships Between Thinocorus orbignyanus (Charadriiformes: Thinocoridae), Lepus europeaus (Lagomorpha: Leporidae), and Equus ferus caballus (Perissodactyla: Equidae) in High-Mountain Grasslands During the Summer Season. Ecologies, 6(3), 57. https://doi.org/10.3390/ecologies6030057

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