•European bison fed on 105 plant taxa during growing season in Białowieża Forest.•Woody species (59.4% of DNA sequences) and forbs (33.6%) dominated in bison diet.•The diversity of plants eaten by ...bison increased with increasing food availability.•Bison continuously adjusts its diet with seasonal availability of non-grass vegetation.•Diet plasticity and use of forest openings allow bison to persist in sheltering forest habitats.
Large herbivores that survived the Pleistocene/Holocene transition are hypothesized to have been forced to take refuge, as a result of environmental changes and human pressure, into forest habitats. Today, there is an open question of the degree to which extant large herbivores are well adapted to the forests that allowed for the herbivores’ persistence. We studied the diet of European bison (Bison bonasus), the largest terrestrial mammal in Europe, to gain insight into the foraging behaviour of a large herbivore, that appears to be primarily adapted to grazing but has been restored to forested habitats. The study population resided in the Białowieża Primeval Forests, Poland. DNA-based analysis of faecal samples revealed strong seasonal and spatial patterns in bison foraging, consistent between sexes. Bison fed on at least 105 different plant taxa. Woody species constituted 59.4% of DNA sequences, and forbs 33.6%. The two most abundant taxa were raspberry (Rubus idaeus) and European hornbeam (Carpinus betulus), which together comprised 31.0% of the dietary sequences and occurred in over 80% of faecal samples. Seasonally, the diversity of plants eaten by bison increased with increasing food availability. During high plant biomass in summer, bison consumed up to 40 different plant taxa. There was little overlap in the composition of the diet from month to month, reflecting the strong seasonality of vegetation abundance and/or its dietary quality. The results indicate high plasticity in bison foraging strategies and response to seasonal changes in biomass and the species composition of plants. Bison are browsers which continuously adjusts their diet with seasonal availability of easily digestible non-grass vegetation. We propose that dietary plasticity and micro-selection for open habitats (gaps and river valleys) within a forested landscape allowed bison to persist in sheltering forest habitats during the Holocene and accommodate to forest environments during species restoration.
Lygus lineolaris (Palisot de Beauvois) is a highly polyphagous herbivore with more than 300 known host plants. The high polyphagy has created logistical challenges for understanding its population ...dynamics. I hypothesized that the primary food resource of this species can be characterized simply, cutting across the multiple host plant species, and enabling a simpler understanding of its population dynamics. The food resource was defined as the apical buds and meristematic tissue and terminal flowers and young seeds. Adult abundance in a habitat was related to the relative abundance of food in the habitat, abundance on a host plant stem was related to the amount of food resource on the stem, and the rate of emigration was lower from host plant patches with higher amounts of food resources.These results suggest that the population dynamics of L. lineolaris depends less on the identity of the host plants and more on the amount of food resource the various host plant species provide.
The Brown Fish-Owl Ketupa zeylonensis is a large nocturnal bird of prey that has a vast distribution range. However, there is a significant literature gap on the ecology of this species in the ...Western Ghats ecoregion, particularly in regard to its food spectrum. In the present study, we assessed the diet composition of this species in the foothills of the Western Ghats of Goa, India. The diet was evaluated by analysing the undigested prey remains in regurgitated pellets obtained from the banks of forest streams and roosting sites. A total of 104 pellets were collected from two localities that exhibited similar landscape characteristics. Our analysis indicated that crabs contributed to a significant proportion of the diet of the species (75.47%), followed by amphibians (frogs, 8.02%), fishes (7.08%), reptiles (snakes, 2.83%), birds (2.36%), scorpions (1.89%), and insects (Odonata, 0.47%). Additionally, 1.89% (n = 4) of the prey items could not be identified due to their disintegrated nature. Furthermore, an assessment of Food Niche Breadth (FNB) indicated that K. zeylonensis exhibited a high degree of specialization in terms of its diet in the study areas.
Pollination plays a vital role in maintaining ecological functioning of ecosystems, and bees are the main pollinating insects in natural and agricultural areas. Identification of bee food sources can ...be carried out directly by observing their visits to flowers, or indirectly by analyzing the pollen they carry. Pollen analysis is employed to determine the breadth of the bees’ dietary niche and understand the relationship between flower traits, pollen grains, and floral resources. While
Exomalopsis
females were previously recorded as pollinators of Solanaceae species, information regarding their trophic niche in agricultural areas remains limited but is essential for the management of these wild pollinators. In this study we accessed the floral resources used by two
Exomalopsis
species (
E. analis
and
E. auropilosa
) through pollen analysis in their scopae, using cultivated
Capsicum
cultivars (Solanaceae) as target plants. Pollen samples from 56
Exomalopsis
females (21 from
E. analis
and 35 from
E. auropilosa
) revealed 58 pollen types belonging to 24 botanical families, with the highest values found for Fabaceae, Asteraceae, Euphorbiaceae, and Rubiaceae.
E. auropilosa
showed greater pollen type richness (46) with 3–10 types per bee, while
E. analis
had 43 types with 3–13 types per individual.
Capsicum
, a pollen, and nectar source constituted approximately 77% of the pollen loads. Most of other plant species identified were arboreal and provided nectar to these pollinators. Trophic niche overlap between
Exomalopsis
species was low. The conservation of wildflowers surrounding pepper cultivations is essential for maintaining these two important pollinators in agricultural areas. Additionally, areas with bare soil can contribute to the persistence of
Exomalopsis
populations.
Existen pocos antecedentes sobre los hábitos tróficos de Tyto furcata en el noroeste argentino, y ninguno en la ecorregión de las Yungas. A partir del análisis de egagrópilas, caracterizamos la dieta ...de esta rapaz en seis localidades de las Yungas de Argentina. Documentamos la composición y la diversidad de los ítems presa y analizamos los parámetros tróficos en el contexto de los diferentes grados de transformación de la vegetación. El estudio incluyó una caracterización general y un análisis estacional. Los roedores constituyeron un 98% del total de presas y fueron los que más aportaron a la dieta en términos de biomasa. Los valores de amplitud de nicho trófico (ANT) y del nicho trófico estandarizado fueron más elevados en comparación con los observados en otras áreas de Argentina. Observamos cambios estacionales importantes en la composición de especies para cada localidad. La ANT fue mayor durante la estación húmeda y el solapamiento trófico entre estaciones fue relativamente alto. No observamos una relación clara entre el grado de modificación antrópica y los parámetros tróficos. Nuestros resultados coinciden con los reportados para América del Sur, con un espectro relativamente amplio de presas y una fuerte selección por roedores cricétidos. Algunas localidades mostraron una tendencia a la disminución de ANT durante la estación seca, lo que reflejaría las variaciones estacionales en la abundancia de pequeños mamíferos, que muestran mayores tamaños poblacionales en invierno. Esto obligaría a la lechuza a adoptar una dieta más generalista en el verano. En estas localidades, la proporción de los diferentes usos del suelo no parece tener una incidencia importante sobre los parámetros tróficos analizados, al menos en nuestra escala de análisis. Aunque nuestros resultados constituyen un punto de partida importante para el estudio del nicho trófico de Tyto furcata en Yungas, resulta evidente la necesidad de estudios adicionales para dilucidar numerosos aspectos vinculados a la ecología de esta rapaz.
Abstract Little is known about the diet of the Chiapas spectacled caiman, Caiman crocodilus chiapasius (Bocourt, 1876), in the southern coast of Mexico. Herein, we analyzed the stomach content of 44 ...caimans divided into 3 size classes in La Encrucijada, Chiapas, Mexico. Within the contents we identified insects, crustaceans, arachnids, fishes, and birds. Hatchlings fed mainly on insects and arachnids, juveniles on crustaceans and insects and sub-adults on crustaceans and fish. Our data show that while the invertebrate intake decreased along different size classes, vertebrates intake increased, and that diet overlapped greater in adjacent size classes. No differences were found in niche breadth (p > 0.05), diet composition (Q = 2.0, p = 0.3678) and prey abundance (X 2 = 1.9756, p = 0.3759) among size classes. Caiman crocodilus chiapasius is protected by the Mexican law in the category of "special protection".
Coprophagous insect communities play a critical role in the decomposition of vertebrate dung and provide ecosystem functions fundamental to modern agriculture. While the ecology of dung beetles is ...rather well understood, niche differentiation in coprophagous flies is poorly studied. Sepsid flies (Diptera: Sepsidae) are a vital part of the European community of coprophages, with 6-7 widespread species of Sepsis often found co-occurring in the same pasture. To advance our ecological understanding of the mechanisms that enable species to coexist, we investigated the oviposition preferences and larval performance of 7 common species of Sepsis in the dung of different large domestic and wild mammals. Substrate preferences and subsequent performance of larvae in laboratory experiments did not vary greatly. All species did very well on cow dung, the most common substrate in Central Europe, but also on dung of horse and wild boar. In contrast, flies did not prefer or grow well in dung of red and roe deer, two of the most common wild vertebrates. Thus there were only minor differences among the species tested along the specialist-generalist (dung) gradient, indicating that differences in the choice of oviposition sites by the adults of the different fly species and larval performance do not constitute a major axis of ecological differentiation. Nevertheless, there was a positive correlation between substrate choice and larval performance indicating the preference of gravid females for particular oviposition sites is adaptive. We conclude that sepsids are common in Europe because they are well adapted to the dung of herbivorous livestock rather than wild animals. Nevertheless, specialization on particular types of dung does not define the niche of Sepsis dung flies and hence plays a minor role in mediating their species diversity.
Assessing the trophic niche and interspecific relationships between related species and determining how the species maintain differences in nutritional niches while coexisting in the same area are ...important topics in ecological research. Therefore, exploring the mechanism of food resource utilization, competition and coexistence among species distributed in the same region is important. In this study, we used fecal samples and metagenome sequencing technology to study the plant feeding habits and coexistence mechanisms of Tibetan macaques (
) and grey snub-nosed monkeys (
) within the same area. In the winter of 2020, we collected a total of 40 fecal samples from Tibetan macaques and grey snub-nosed monkeys; of those, 29 samples were considered valid and were analyzed using DNA metabarcoding. The results showed that in winter, Tibetan macaques consumed plants from 117 families and 184 genera, whereas grey snub-nosed monkeys consumed plants from 109 families and 165 genera. Diversity analysis revealed that there was a significant difference in the food composition of Tibetan macaques and grey snub-nosed monkeys. Tibetan macaques had a broader food niche width than grey snub-nosed monkeys at the family and genus levels. In winter, the food niches of Tibetan macaques and grey snub-nosed monkeys almost entirely overlapped (0.99). Our research provides detailed dietary data for Tibetan macaques and grey snub-nosed monkeys and valuable information that can aid in conservation efforts targeting these species.
Some species of bees restrict foraging to the twilight period before sunrise or after sunset. Among the plants sought by these nocturnal bees are species described as chiropterophilous, such as
...Caryocar brasiliense
. The flowers of this species open in the evening and provide resources until dawn. We determined the pattern of flower visitation by nocturnal bees and their role in pollination and fruit set of
C. brasiliense
and evaluated its importance as floral resource for nocturnal bees. We analyzed the pollen composition of cell provisions of nocturnal bees of
Ptiloglossa
(Colletidae) and compared its scent with floral scent compounds of
C. brasiliense
. Moreover, we conducted a pollinator exclusion experiment to determine the contribution of nocturnal bees to its fruit set. Disregarding bats,
Ptiloglossa latecalcarata
and two species of
Megalopta
(Halictidae) were consistent nectar and pollen gathering visitors, along with some social diurnal bees. The visitor exclusion experiment revealed that bee visits do not result in fruit set, which only occurs through visits by bats. The flowers supply a significant amount of pollen for nocturnal bees, as demonstrated through pollen analysis of brood cells and scopa loads. This interaction, therefore, is only beneficial to the commensalist bees. The scent collected from brood cells was dominated by hexanoic acid and 1-hexanol and differed strongly from the floral scent of
C. brasiliense
. These results substantiate that bat-pollinated flowers are an important part of the food niche of nocturnal bees, which implies that they are sensorially equipped to recognize floral traits shaped by bats.
We examined the influence of climate and habitat changes on the occurrence of butterflies in South Korea, using data recorded in two different periods: (i) past (1938–1950) and (ii) present ...(1996–2011). Butterfly species were classified according to their distribution types (northern, southern, and miscellaneous) to examine the effect of climate change. They were also classified according to three different habitat types (forest interior, forest edge, and grassland) to examine the effect of habitat change. Three types of food niche (monophagous, oligophagous, and polyphagous) were identified. A community temperature index (CTI), based on the species temperature index of each species, was calculated for past and present butterfly communities to estimate range shifts of butterflies at the community level. At the species level, range shifts of butterflies were calculated as a shift of the mid-zone of the distribution range in terms of latitude and temperature. The results showed that a change in the occurrence of butterflies was not significantly different among the three distribution types. The CTIs were not different between past and present communities, and the mid-zones of distribution range in latitude and temperature did not change. These results indicate that the occurrence change of butterflies was not significantly influenced by climate change but was instead influenced by habitat change from bare-ground or grassland to forests over 60 years. There was an increase in forest species and a decrease in grassland species, reflecting the effects of large-scale reforestation in South Korea over the last few decades. The reforestation has resulted in an increase in monophagous (oak-feeding) butterflies. Our results show that habitat change played a key role in the occurrence of Korean butterflies and may be confounding any possible influence of climate change.
•We examined the influence of climate and habitat changes on the occurrence of over 60 years.•A community temperature index (CTI) was calculated for past and present butterfly communities.•CTI was used to estimate range shifts of butterflies at the community level.•Climate change did not have a significant influence on the occurrence change of butterflies.•Habitat change alone influenced the occurrence of Korean butterflies without significant influence of climate change.
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