The diet of Impala (Aepyceros melampus) in the Sengwa Wildlife Research Area, Rhodesia

The seasonal variation in the plant morphological part composition of the dict of Impala in the Sengwa Wildlife Research Area, Rhodesia, was determined by the analysis of rumen content samples from shot animals. The grass species composition of the diet was examined by microscopic identification of grass fragments found in the rumens. The seasonal variation in the dicotyledonous species composition of the diet was studied by direct observation of feeding animals. The protein contents of the rumen contents and faeces were used as measures of diet quality. In the wet season, grass was selected in preference to dicotyledonous plants, and grass leaf was the preferred plant part. In the late wet and early dry seasons, forbs were the principal food. The proportion of woody dicotyledons in the diet was at a maximum in the mid-dry season, when diet quality was at a minimum. Diet quality was directly related to the proportion of grass in the diet. Female Impala had a significantly higher quality diet than males, probably as a result of differential habitat selection.     

Vole diet on experimentally managed reforestation areas in northern Sweden

In northern Sweden two field experiments with the reforestation techniques soil scarification, ploughing, burning and grass herbicidal treatment were performed. Small rodents were trapped regularly on the managed plots and their stomachs were examined microscopically for diet composition. Both bank voles Clethrionomys glareolus and field voles Microtus agrestis were common on the reforestation areas while only a small number of grey-sided voles Clethrionomys rufocanus were taken. All three species underwent a population cycle during the studies. The management techniques generally resulted in small and irregular effects on the food selection. The most pronounced changes were lower intake of grasses by M. agrestis after herbicidal treatment and of filamentous tree lichens by C. glareolus after most treatments.
Both bank voles and field voles ate predominantly forbs in the summer half of the year, whereas the field voles took also a considerable amount of grass. As a complement to green vegetable-matter bank voles ate berries and fungi in summer-autumn and tree lichens at other times of the year, but seeds and animals food only in very small amounts. Ail three species consumed large quantities of dwarf-shrubs in autumn and especially in winter. Considerable amounts of bark were eaten by field voles and a smaller proportion by bank voles in autumn-winter.
Both for bank and field voles there were indications of worsening food conditions as the population cycle went on, There were, for example, an increase in grass and bark intake in field voles and a decrease in seeds and berries for the hank vole.     

The integrated processing response of voles to fibre content of natural diets

1. Two species of voles were fed high fibre (barnyard grass) and low fibre (alfalfa) diets to test the integrated processing response (IPR) hypothesis. This hypothesis states that many herbivores are able to maintain their required intake of digestible nutrients and energy on diets with very different fibre content because of compensatory changes in intake of food, size of gastro-intestinal (GI) tract, passage rates of fibre and absorptive capacity of the GI tract.
2. As predicted by the IPR hypothesis, each species of vole maintained a similar intake of digestible dry matter on the two different diets. Both species also had greater intake, larger GI size, shorter mean retention times and greater GI mass (an indicator of epithelial mass and absorptive capacity) when fed grass than when fed alfalfa.
3. The two species differed in that meadow voles, the more active species, had greater total intake and obtained a greater amount of digestible dry matter from either diet than did prairie voles. Meadow voles also consume more grass in the field than do prairie voles, and they digested grass better than did prairie voles. Prairie voles, which consume more dicots in the field, digested alfalfa better than did meadow voles.
4. Meadow voles had longer GI tracts, particularly small intestines, than did prairie voles, which may be linked to their greater ability to digest grass. However, meadow voles did not have larger caeca than prairie voles, even though caecal size increased on grass diets for both species. The GI size of prairie voles fed grass increased more than did the GI size of meadow voles, and this may have enabled prairie voles to utilize a grass diet, though they prefer to eat dicots. Greater selection of leaves, which have less fibre than stems, and longer mean retention times of food may account for better digestion of alfalfa by prairie voles.     

Diet composition and habitat selection of eland in semi-arid shrubland

This study investigated the diet composition and habitat selection of eland in semi-arid shrubland, dominated by microphyllous and leptophyllous browse species offering low leaf: stem ratios. Browse (succulent, forb and woody species) contributed 94% to the annual diet of eland. The annual proportion of grass in eland diet was low (6%), even though palatable grass species were abundant in habitats favoured by eland. Most grass was eaten in the early wet season when grasses offered young green foliage. Woody species comprising dwarf shrubs and shrubs made up the bulk of the food eaten by eland. In each season, favoured woody species contributed substantial proportions to the diet of eland. Eland used the plateau habitats in the early wet season, but valleys and slopes in the late wet and dry seasons. Habitats favoured by eland contained high abundances of plants of woody species favoured by eland. Chemical analysis indicated that woody species favoured by eland offered lower total fibre contents than other woody species available to eland. The results of the study indicated that eland are browsers that select browse of low fibre content.     

The natural regulation of buffalo populations in East Africa: The food supply as a regulating factor,and competition*

Evidence is presented to show that both the quality and quantity of food available to a buffalo population falls below the minimum maintenance requirements of that population at certain times of the year. In the Serengeti grasslands there was a shortage of the only good quality component, grass leaf, in the dry season, with the result that the animals consumed an increasing proportion of poor quality food such as grass stem. By the end of the dry season the diet had dropped in quality below the minimum maintenance level. In areas such as Mt. Meru where there was a more continuous growing season, the high density of animals kept the standing crop of leaf at a low level. During the cooler dry season the growth of leaf became insufficient in quantity for the maintenance requirements of the population. These two quite different situations suggested that food shortage was a more general phenomenon in eastern Africa. Various measurements of feeding behaviour were made. Total grazing time per 24 h did not differ between seasons but ruminating time may have increased as the season became drier and could have been a response to the more fibrous food. Analysis for cycles of activity showed that there was more temporal organization during the dry season. These changes in activity cycles appeared to be related to the increase in energy expenditure produced by heat stress and sweating. Old animals with poor teeth did not compensate for the poor food supply by changing their feeding behaviour. There was a positive relationship between annual rainfall and mean crude density in different areas of eastern Africa, indicating that regulation was taking place. Since rainfall determined the amount of available food, it could have operated through the food supply. On a finer scale it was found that the extent of the preferred riverine habitats was also related to density. Thus rainfall, the extent of riverine habitat and perhaps soil moisture were three limiting factors that determined mean density and all could have taken effect through the food supply. As a result of initial selective grazing the amount of available leaf declined as the dry season progressed to the extent that by the end of the season the proportion of this component in the diet fell to a very low level. The impact of the population on its limited food supply indicated that intra-specific competition was acting as the cause of regulation. Measurements of wildebeest eating the same food in the same habitats as buffalo showed that inter-specific competition was also taking place. A small proportion (7“) of the wildebeest population could have reduced the buffalo population by approximately 18^o,‘, from its potential population size. The buffalo population in the Serengeti was regulated by adult mortality which was caused by undernutrition as a result of food shortage. This food shortage was caused by intra- and inter-specific competition. The effect of predation and disease was to hasten the response of the population to changes in the food supply. The limiting factors determining the mean level of the available food were, amongst others, rainfall, soil moisture and the extent of the preferred riverine habitat. The effect of interspecific competition could result in a complex regulation of populations through their food supply. There appears to be no foundation for hypotheses which invoke over-utilization or damage as a consequence of regulation through food.     

Summer diet selection of snowshoe hares: a test of nutritional hypotheses

We examined summer diet selection by snowshoe hares in the southwestern Yukon, Canada, and attempted to explain how plant qualities such as nutritional content (protein, energy, fiber, water) and defensive compounds affect hare food choice. Male hares were placed in enclosures in natural vegetation areas dominated by shrubs and in both open and closed spruce forests. Each site contained a variety of herbaceous plant species. After 24 h, hares were sacrificed, their stomachs collected, and the contents removed and analyzed. Of the 30 plant species recorded in the enclosures only 10 were identified in the stomach contents of the hares. The summer diet is composed predominantly of five plant species; Lupinus arcticus, Salix spp. Shepherdia canadensis, Betula glandulosa and Festuca altaica. The selection of these species changes between sampling times. Protein, energy and water contents were highest in leaf tissues of most species early in the season, and most species had an increase in fiber through the summer. Protein content consistently explains the largest amount of variation in diet selection, although protein selection is modified by extremely high concentrations of defence compounds. It is likely that hares are not protein limited and are selecting for other plant characteristics correlated with protein content such as energy content. It is significant that hares continue to ingest heavily defended species (e.g. Shepherdia canadensis, B. glandulosa and L. arcticus) when many less defended plants are available to be eaten (e.g. F. altaica, Epilobium latifolium and Anemone parviflora). Our results support the idea that hares are selecting dietary items on the basis of energy content. No single plant species can satisfy all of the hares’ nutritional requirements and the selection patterns may reflect the need to balance many conflicting plant qualities.     

The natural regulation of buffalo populations in East Africa: Introduction and resource requirements*

Although it would appear that regulation in animal populations is highly probable, the evidence for it in nature is meagre. The various hypotheses on regulation are outlined in order to point out the critical evidence needed to test them. A population of the East African buffalo has been studied since 1965 with a view to obtaining this information. The ecological requirements including habitat selection and food selection are described. Using Association analysis the ‘best available’ habitat for buffalo was found to be a combination of riverine grassland and forest. This was most pronounced in the dry season when other habitats became less suitable due to the grass drying out and becoming unsuitable food. The movements between vegetation types were correlated with changes in rainfall and with the area of burnt ground after grass fires. Hence the movements could be attributed to changes in the food supply. Within the ‘best available’ habitats the buffalo ate grass exclusively but not all grass was food. The most preferred component was the combined grass leaf and leaf base, this being the most nutritious part of the plant. This component was predominant in the diet during the rains but declined to a minimum by the end of the dry season despite the animals' ability to select for it.     

The savanna ecology of Kidepo Valley National Park

(1) Food habits of elephant and giraffe were recorded in short sample periods over several years using the feeding minutes technique. (2) Twelve species of common plants were collected on these occasions, separated into their main parts and analysed chemically. (3) Damage to trees was also recorded at intervals. (4) Fifty-nine species of plant were eaten by elephant. During wet months their diet was predominantly grass but during dry months woody vegetation became more important. Giraffe were observed eating from thirty-nine species of plant which were almost entirely browse throughout the year. At least eighteen of these species were also eaten by elephant. (5) Three of the browse species most important to giraffe were also important to elephant in dry seasons. In the driest month the species eaten by giraffe formed more than two-thirds of the observed diet of elephants. (6) Chemical analyses of plants show that browse leaves had a higher level of protein, fat and minerals than most other plants. (7) The trunk of an elephant and the tongue of a giraffe are highly sensitive organs which permit food selection. Elephant in particular appeared to alter their food habits seasonally and it is suggested that this may be an attempt to obtain a balanced intake of nutrients. (8) Due to the effect of elephant and other agencies there is an accelerating decline in Acacia gerrardii woodlands. Browsing and fire are independently preventing their regeneration. (9) The extensive overlap of food requirements on preferred but diminishing browse resources implies potential if not already existing competition between elephant and giraffe. (See Part III.)     

Palatability factors and nutritive values of the food of buffaloes (Syncerus caffer) in Uganda

The food preferences of tame buffaloes grazing different vegetation types were recorded. The effects of fire and rainfall were investigated. By initiating a new growth cycle, fire altered the food habits of large herbivores and also the distribution of small mammals. Seasonal variations in the effect of rainfall on plant growth explains why preferences did not change in proportion to precipitation. The more important grasses were collected and their parts analysed physically and chemically. Their stem to leaf ratio is considered to have influenced the species eaten by coarse grazers such as buffalo. A broad correlation was obtained between buffalo preferences and the percentage green leaf of Hyparrhenia filipendula and Themeda triandra. This correlation was improved when preferences were compared with the number of grams green leaf carbohydrate per 100 g dry grass. There was a negative response to the silica present in dead leaves, but stem fibre appeared to have little effect on preferences. A grazing animal experiences a combination of attractants and repellants, i.e. green leaf carbohydrate and protein less stem fibre and dead leaf silica. Other palatability factors were noted, in particular tannins and oils in grasses of the tribe Andropogoneae. These may act as repellants, possibly only when the grazing animal has alternative vegetation from which to choose. The mineral content of grasses appeared to be adequate and calcium and phosphorus were present in about the required proportions. The observations support the belief that selective grazing enables a herbivore to consume a diet of significantly higher nutritive value than that of the average sward. Browsing and new growth after fire help compensate for the low nutritive value of pasture during the dry season. The nutritive value of the diet is considered to be the proximal factor in the seasonal cycle of reproduction of the buffalo and probably the ultimate factor in the reproduction of certain other ungulates and rodents.     

Seasonal variation in feeding habits and diet selection by wild boars in a semi-arid environment of Argentina

The wild boar, Sus scrofa, was first introduced for hunting purposes in Argentina in 1906 and presently occupies a wide range of habitats. Understanding the food habits of invasive species is important for predicting the effects of animal food consumption on the environment and on human activities, such as farming. The wild boar is an omnivorous, opportunistic species whose diet is determined by the relative abundance of different types of foods. In general, the wild boar’s diet has been widely studied in the world, both as a native and invasive species, but little is known regarding food resource selection in the Monte Desert biome. Our study assessed the seasonal variation in the diet of wild boars, as well as the nutritional quality of consumed items. Further, we determined the diet selection of this species. Diet analyses were based on faecal samples collected over two seasons (wet and dry) in 1 year. Herbs were the most frequently consumed food item, with wild boars showing a selection for them in both seasons. The wild boar uses food resources according to seasonal availability (larger trophic niche breadth under higher plant diversity, as in the wet season). In turn, within each season, it selects items of high forage quality and high carbohydrate contents. In conclusion, this foraging strategy enables wild boar to maximize energy budget through food selection in order to survive in a semi-arid environment such as the Monte Desert.     

Seasonal and inter‐island variation in the foraging strategy of the critically endangered Red‐headed Wood Pigeon Columba janthina nitens in disturbed island habitats derived from high‐throughput sequencing

We studied the feeding ecology of the critically endangered Red‐headed Wood Pigeon Columba janthina nitens, a subspecies endemic to a very remote and highly disturbed oceanic island chain, the Ogasawara Islands. An analysis based on high‐throughput sequencing (HTS) was undertaken on 627 faecal samples collected over 2 years from two island habitats, and food availability and the nutrient composition of the major fruits were also estimated. The HTS diet analysis detected 122 food plant taxa and showed clear seasonal and inter‐island variation in the diet of the Pigeons. The results indicated a preference for lipid‐rich fruits, but the diet changed according to the availability of food resources, perhaps reflecting the foraging strategy of the Pigeons in isolated island habitats with poor food resources. Pigeons also frequently consumed introduced plants at certain times of year, perhaps compensating for the lack of preferred native food resources. However, the degree of dependence on introduced plants appeared to differ between the two island habitats, so the different impacts of introduced plant eradication on the foraging conditions for the Pigeons on each island should be considered. HTS diet analysis combined with field data may be useful for monitoring the foraging conditions of endangered species and may also inform an appropriate conservation strategy in oceanic island ecosystems with complicated food webs that include both native and introduced species.     

Baboon diet: a five-year study of stability and variability in the plant feeding and habitat of the yellow baboons (Papio cynocephalus) of Mikumi National Park, Tanzania

The habitat and plant feeding of 64 well-habituated, individually identified adult male and female yellow baboons was studied for 5 years at Mikumi National Park, Tanzania. Variation across the years showed that a study of only one or two years would have been incomplete and misleading. The list of baboon food species obtained from Mikumi is considerably larger and more diverse than any previously reported. One to six plant parts were eaten from each of more than 180 species. The 25 most common tree genera all contained species used for food. Of the 50 most common grass, shrub and herb genera, 93% included plant foods. Using months in which a species was eaten during at least one year of the study, 21 staple species were eaten during a mean of 8.86 months and 7 were eaten in all 12 months. Although many foods were from commonly available plant species, 15 such species were only rarely eaten. The number of parts of a species eaten per month and an estimate of the amounts eaten per month both varied with temperature and rainfall, being lowest near the end of the cool, dry season. There were substantial differences from year to year in the timing and amount of food production of many species; nevertheless, the same broad feeding pattern was repeated in each of the 5 years of the study. Despite yearly variation in food availability, 14 or more staples and other common foods were eaten in any given month. If crops of many of these foods were to fail, a large number of less commonly eaten species could be substituted. Baboons are eclectic feeders that appear to be optimizing their diet by selective feeding from among a wide array of available foods in an ever-changing floristic environment.     

Size class structure and tree dispersion patterns in old-growth cedar-hemlock forests of the northern Rocky Mountains (USA)

Summary The relationship between the food selection of four leaf beetle species (Phratora vitellinae, Plagiodera versicolora, Lochmaea capreae, Galerucella lineola) and the phenolic glycosides of willow (Salix spp.) leaves was tested in laboratory food choice experiments. Four willow species native to the study area (Eastern Finland) and four introduced, cultivated willows were tested.The willow species exhibited profound differences in their phenolic glycoside composition and total concentration. The food selection patterns of the leaf beetles followed closely the phenolic glycoside spectra of the willow species. Both the total amount and the composition of phenolic glycosides affected the feeding by the beetles. Phenolic glycosides apparently have both stimulatory and inhibitory influences on leaf beetle feeding depending on the degree of adaptation of a particular insect. Very rare glycosides or exceptional combination of several glycoside types seem to provide certain willow species with high level of resistance against most herbivorous insects. Analogously the average absolute amount of leaf beetle feeding was lower on the introduced willows than on the native species to which the local herbivores have a good opportunity to become adapted.     

桂西壮族饮食文化中野生食用植物的民族植物学研究

运用民族植物学方法,以广西西部的1市1区10县为研究区域,对桂西壮族饮食文化中利用野生食用植物的传统知识进行了调查和研究.结果显示:桂西壮族饮食文化中常用的野生食用植物有46科102种,其中菊科(Asteraceae)种类最多(13种),其次为苋科(Amaranthaceae)、伞形科(Umbelliferae)、蔷薇科(Rosaceae)和豆科(Leguminosae)(各6种).食用部位常为嫩枝叶、果实、全株、花、根和茎等,其中,食用部位为嫩枝叶的种类最多(48种),食用部位为根和茎的种类最少(8种),食用部位为果实、全株和花的种类分别有18、17和11种.食用方法有炒、煮汤、生食、凉拌、水煮、茶饮、上汤和配菜等,常见的食用方法为炒和煮汤.采摘时间主要为春季和夏季,部分种类可全年采食.不同区域的壮族民众对野生食用植物的选择具有随机性,主要依据方便、易得、适用、无污染等标准进行选择,且生活在不同区域、不同环境的壮族民众对野生食用植物的选择具有较明显差异.综合分析结果表明:桂西壮族民众拥有丰富的利用野生食用植物的传统知识,具有食用植物种类丰富、食用部位多样、食用方法多样等特点,形成了富有民族特色的饮食文化.此外,根据研究结果,对桂西壮族特色饮食文化的保护和传承进行了探讨,并对当地野生食用植物资源的可持续利用提出了一些建议.     

Phenology of figs in Budongo Forest Uganda and its importance for the chimpanzee diet

This paper reports on the phenological patterns of figs in Budongo Forest, Uganda, and how it relates to chimpanzee food availability in different seasons. In addition, we analysed the dung of chimpanzees to understand the composition of fruits in their diet. The aim of our study was to assess Ficus phenology and how it affects chimpanzee diet. Fifteen species of figs were monitored for fruit (syconium) and leaf phenology between June 2000 and 2001. Ficus fruit production varied significantly between and within species, and also with tree trunk and crown diameters. Fig fruit production was asynchronous and individual fig trees produced crops from one to five times in a year. In addition to fruits, chimpanzees fed on young leaves of some Ficus species. Shedding of old Ficus leaves coincided with the dry season, followed by appearance of young leaves. The dry season in Budongo is a period of general fruit scarcity. The combination of fig fruits and young leaves make up the most important food in the diet of chimpanzees. From the chimpanzee dung, more than 78% of seeds comprised fig ‘seeds’ (nutlets) and the rest of the diaspores were from other tree species. Our findings suggest that chimpanzees disperse large number of diaspores in their dung, thereby serving as important agents of natural forest regeneration.     

Plant species effect on the decomposition and chemical changes of leaf litter in grassland and pine and oak forest soils

Aims

The aim of this study was to examine the effect of plant species differing in functional and phylogenetic traits on the decomposition processes of leaf litter in a grassland of Japanese pampas grass (Miscanthus sinensis) and adjacent forests of Japanese red pine (Pinus densiflora) and Japanese oak (Quercus crispula), representing sequential stages of secondary succession.

Methods

The litterbag experiments were carried out for 3 years in a temperate region of central Japan.

Results

The decomposition constant (Olson’s k) was 0.49, 0.39, and 0.56/year for grass, pine, and oak, respectively. Nitrogen mass decreased in grass leaf litter during decomposition, whereas the absolute amount of nitrogen increased in leaf litter of pine and oak during the first year. Holocellulose in grass leaf litter decomposed selectively over acid-unhydrolyzable residues more markedly than in leaf litter of pine and oak. ¹³C nuclear magnetic resonance analysis also revealed a decrease in the relative area of O-alkyl-C in grass.

Conclusions

The different decomposition among the three litter species implied that the secondary succession from grassland to pine forest and from pine to oak forests could decrease and increase, respectively, the rate of accumulation and turnover of organic materials and N in soils.     

Interference effects in white clover genotypes grown as pure stands and binary mixtures with different grass species and varieties

Six white clover genotypes and eight grass varieties belonging to four different species were grown both in monoculture and as grass-legume binary mixtures in dense swards for two years under a mowing regime and a management including N fertilization. Dry matter yield and yield-related traits were recorded to investigate some aspects of inter-specific interference in white clover-based mixtures and to define a methodology for selecting genotypes of this clover suited to conditions of association. Clover was at a competitive disadvantage in most mixtures. Differences among grasses for aggressiveness were related more to variety vigour than to species. Clover compatibility proved specific only in relation to grass vigour. Variation among clovers for tolerance to competitive stress involved significant cross-over interactions passing from monoculture to severe stress conditions for clover yield and other traits, and was related positively to stolon density and negatively to yield and leaf gigantism traits recorded in monoculture. Clover selection for high levels of competitive stress seems possible either by genotype assessment in stress conditions or by a combination of high yield and stolon density assessed in monoculture.     

Fallback Foods of Red Leaf Monkeys (Presbytis rubicunda) in Danum Valley, Borneo

Animals in Southeast Asia must cope with long periods of fruit scarcity of unpredictable duration between irregular mast fruiting events. Long-term data are necessary to examine the effect of mast fruiting on diet, and particularly on the selection of fallback foods during periods of fruit scarcity. No such data is available for colobine monkeys, which may consume substantial amounts of fruits and seeds when available. We studied the diet of red leaf monkeys (Presbytis rubicunda, Colobinae) in Danum Valley, Sabah, northern Borneo, using 25 mo of behavioral observation, phenology and vegetation surveys, and chemical analysis to compare leaves eaten with nonfood leaves. The monkeys spent 46% of their feeding time on young leaves, 38% on seeds, 12% on whole fruits, 2.0% on flowers, 1.0% on bark, and 1.2% on pith. They spent more time feeding on seeds and whole fruit when fruit availability was high and fed on young leaves of Spatholobus macropterus (liana, Leguminosae) as fallback foods. This species was by far the most important food, constituting 27.9% of the total feeding time, and the feeding time on this species negatively correlated with fruit availability. Consumed leaves contained more protein than nonconsumed leaves, and variation in time spent feeding on different leaves was explained by their abundance. These results suggest that red leaf monkeys show essentially the same response to the supra-annual increase in fruit availability as sympatric monogastric primates, increasing their seed and whole-fruit consumption. However, they depended more on young leaves, in particular Spatholobus macropterus, as fallback foods during fruit-scarce periods than did gibbons or orangutans. Their selection of fallback food appeared to be due to both nutrition and abundance.     

Folivory in the white-tipped plantcutter Phytotoma rutila: seasonal variations in diet composition and quality

Plantcutters (Phytotomidae) represent the only Passeriformes with a predominantly folivorous diet. Little is known however about their feeding habits and adaptations for leaf consumption. Here we analyze the relationship between diet composition and nutritional value in the white-tipped plantcutter Phytotoma rutila in a Chaco woodland in Córdoba, Argentina. The white-tipped plantcutter consumed mainly dicot leaves (91%), complemented with a small proportion of fruits (7%) and flowers (2%). Eleven plant species were utilized, of which five were strongly dominant: Lycium cestroides (38%), Prosopis alba and P. nigra (28%), Celtis tala (22%), and Schinus longifolius (8%). No animal food was consumed. The leaf material ingested by the white-tipped plantcutter had high protein content and low proportion of fibers and phenols. In multivariate analysis, leaf chemical properties accounted for over 81% of the variation in diet composition throughout the year. However, only protein and phenols content related significantly with diet composition in single regressions. The quality index that relates protein with lignin and phenols showed the highest correlation with diet composition. Availability of highly nutritive leaves of Lycium cestroides during the dry season seems to be a key factor for the occurrence of the white-tipped plantcutter in the study area. Our results confirm that plantcutters are truly folivorous passerine species, being able to obtain a highly nutritional diet throughout the year.