Parrots consume sodium‐rich palms in the sodium‐deprived landscape of the Western Amazon Basin

Herbivorous animals face shortages of different minerals in different geographic areas. In the Amazon Basin, sodium is often limiting, driving herbivores to seek supplemental sources. In the lowlands of the western Amazon Basin, parrots commonly consume sodium‐rich soils at clay licks but lick use varies widely among species, and to date, parrots in the region have not been reported consuming other supplemental sodium sources. We document 11 species of psittacines consuming sodium‐rich leaves and trunks of Attalea butyracea palms growing on sodium‐rich soils in lowland Peru. Consumed palms had more sodium and less potassium than uneaten A. butyracea palms and other palm species in the area. Among A. butyracea palm parts, sodium and Na:K ratios were highest in trunks (consumed by parrots in 94% of the 387 foraging bouts recorded) and lowest in leaves (consumed in only 14% of foraging bouts). The low potassium and high Na:K ratio suggest that birds may be seeking not just any sodium sources, but those low in potassium, as potassium is known to exacerbate dietary sodium shortages. Use of the palms and species’ abundance in the study area were not correlated. Instead, parrot species that consumed palms the most were those that use relatively few traditional soil clay licks. This finding suggests that parrot species in the region have fundamental differences in preferred strategies for obtaining supplemental sodium and may help explain documented interspecific differences in geophagy.     

Diet and Geophagy Across a Western Amazonian Parrot Assemblage

We identified species‐ and community‐level dietary characteristics for a species‐rich Amazonian parrot assemblage to determine relationships among dietary metrics and use of geophagy sites. Previous studies suggest that soil is consumed at geophagy sites in this region mainly to supplement dietary sodium. We accumulated 1400 feeding records for 16 parrot species over 2 yr and found that seeds, flowers, and fruit pulp featured prominently in diets, while bark, insects, and lichen were consumed in small quantities. Food availability across 1819 trees was measured, and we found that flower availability was highest in the dry season and fruit production peaked in the wet season, but that phenology patterns of the 20 most commonly foraged plant species suggest no serious food bottlenecks. Partitioning of available food resources among the 13 most commonly encountered parrots is suggested by an ordination analysis (DCA), which placed the large macaws (Ara) with the Amazona parrots at the ‘primary forest’ end of a dietary resource axis and four smaller species at the ‘successional forest’ end of the axis. Parrot species associated with successional forest also consumed less plant species overall. Furthermore, these parrot species consuming successional forest resources had higher claylick visitation rates than those consuming primary forest resources suggesting they derive the greatest benefits from soil consumption.     

Parrot claylick distribution in South America: do patterns of “where” help answer the question “why”?

Geophagy is well known among some Neotropical parrots. The clay apparently adsorbs dietary toxins and/or provides supplemental nutrients. We used location data and 23 environmental layers to develop a predictive model of claylick distribution using Maxent software. We related species characteristics to claylick use and examined how parrot assemblages using claylicks changed with distance from the centre of claylick distribution. Fifty‐two parrot claylicks were reported from an area of ca 4 million km² but over 50% were restricted to a 35 000 km² region of southeast Peru and northern Bolivia. Claylicks were strongly associated with moist forest on younger (<65 millions of yr) geological formations and exposed river banks. The predictive model of claylick distribution matched our reported range well, with precipitation of warmest quarter, land cover, temperature seasonality, and distance from the ocean being most important predictors of claylick presence. Twenty‐six of the region's 46 parrot species visited claylicks. Species differed greatly in their lick use, but body size, dietary breadth, abundance and other traits were poor predictors of lick use. We are confident that our survey identified the distribution of major parrot claylicks in South America, although less conspicuous parrot geophagy may occur elsewhere. We suggest that claylick distribution reflects both underlying geology (allowing claylick formation in only some regions) and the physiological need for geophagy among parrots in different parts of the continent. Data on the latter are inconclusive, but we argue that parrot claylick distribution supports the contention that geophagy is related more to sodium deficiencies than to protection from dietary toxins.     

不同类型表面活性剂在土壤上的吸附特征比较研究

应用平衡振荡法,研究了阴、阳和非离子表面活性剂在土壤上的吸附．结果表明,阳离子表面活性剂十六烷基三甲基溴化铵能强列吸附在6种不同性质的土壤上,吸附等温线为L型,分配常数Kd,为3．0×10^2～48×10^2L·kg^-1;阴离子表面活性剂十二烷基苯磺酸钠、非离子表面活性剂OP及Tween-20的吸附等温线随土壤类型不同而不同,有L、S等型,吸附强度远弱于阳离子表面活性剂,Kd分别大体处于5．3～39、0．13～0．44(Tween-20)和4．4～22．4L·kg^-1(OP)．阳离子表面活性剂的土壤最大吸附量与土壤阳离子交换容量呈线性相关．低浓度范围内,阴离子表面活性剂的土壤分配常数与土壤粘粒含量呈正相关．同时土壤颗粒表面的电荷特性也影响吸附．非离子表面活性剂的Kd与土壤粘粒、砂粒、粉沙含量及表面积存在经验函数关系．     

Phosphorus in a model pond study: I sediment selection and preparation

We chose two surface soils with contrasting textures as model sediments for a model pond study. One soil, a calcareous clay, had a relatively high natural phosphate content and a large phosphate adsorption capacity. The second soil, a non calcareous loam, had a relatively low natural phosphate content and a small phosphate adsorption capacity. Chemical characteristics of both soils were roughly proportional to mineral surface area.Pasture sites of each soil were tilled to a depth of 15 cm and two plots at each site were fertilized by hand with triple superphosphate. A third plot at each site was left unfertilized. After fertilization the plots were mechanically mixed and left fallow for 2 to 3 months. Then the plots were resampled and equilibration phosphate concentrations were determined again. Results showed significant phosphate fixation by the clay soil but no fixation by the loam soil.Research Soil Scientist, Botanist, Physical Science Technician and Physical Science Technician, respectively, USDA-ARS Agric. Water Quality Management Lab.Contribution from the USDA-ARS agricultural Water Quality Management Lab., Durant, OK 74701.     

Mountain gorilla geophagy: A possible seasonal behavior for dealing with the effects of dietary changes

Geophageous Rwandan mountain gorillas excavate and eat weathered leucite-rich regolith (subsoil C horizons) from the slopes of Mount Visoke in the Virunga Mountains. In the months of the dry season, the gorillas reportedly ingest a halloysitic natural earth having a chemical composition similar to that of Kaopectate, a pharmaceutical used by humans to treat gastrointestinal upsets. Several plants known to contain potential toxins are consumed more heavily by gorillas in these months. New information from geochemical and mineral analyses suggests that geophagy may alleviate intestinal problems associated with changes in their diet because the ingested weathered regolith,containing halloysitic clay minerals, may act as a pharmaceutical agent that helps to adsorb toxins and to control dehydration in the dry season.     

Geophagy in masked titi monkeys (Callicebus personatus melanochir) in sBrazil

Geophagy was observed 14 times during an 11-month field study on the ecology and behavior of masked titi monkeys (Callicebus personatus melanochir). Geophagy took place in 12 cases on the surface of a leaf-cutting ant mound (Atta spec.). Analysis of chemical composition and natural features of the soils consumed by the monkeys showed elevated concentrations of several elements. In contrast, a lower concentration of carbohydrates was found in the ant mound sample compared to random non-ant mound soil samples. No difference in the concentration of clay elements, pH-value or percentage of organic matter was found between ant mound samples and randomly collected soil samples. Comparison of used versus not used samples failed to reveal significant clues about function of geophagy. However, chemical and physical properties of soils ingested support previous hypothesis that this behavior may aid in the adsorbtion of plant toxins.     

Geophagy among primates: adaptive significance and ecological consequences

We review geophagy, or soil ingestion, in primates. This behaviour is widespread and is presumed to be important to health and nutrition. Primates may engage in geophagy for one or a combination of reasons. Here we present, and make a preliminary assessment of, six nonexclusive hypotheses that may contribute to the prevalence of geophagy. Four hypotheses relate to geophagy in alleviating gastrointestinal disorders or upsets: (1) soils adsorb toxins such as phenolics and secondary metabolites; (2) soil ingestion has an antacid action and adjusts the gut pH; (3) soils act as an antidiarrhoeal agent; and (4) soils counteract the effects of endoparasites. Two hypotheses pertain to geophagy in supplementing minerals and/or elements: (5) soils supplement nutrient-poor diets and (6) soils provide extra iron at high altitudes. In addition to these hypotheses, geophagy may satiate olfactory senses, serve as a famine food and finally may have no function at all. We draw together a large body of information from various sources to assess these hypotheses and suggest some tests to understand the function of geophagy. Our review suggests that primates engage in geophagy for a number of reasons that are nonexclusive. We conclude that mineral supplementation, adsorption of toxins, treatment of diarrhoea and pH adjustment of the gut seem the most plausible reasons why primates engage in geophagy. Copyright 2000 The Association for the Study of Animal Behaviour.     

Effect of proteins on reovirus adsorption to clay minerals

Organic matter in sewage, soil, and aquatic systems may enhance or inhibit the infectivity of viruses associated with particulates (e.g., clay minerals, sediments). The purpose of this investigation was to identify the mechanisms whereby organic matter, in the form of defined proteins, affects the adsorption of reovirus to the clay minerals kaolinite and montmorillonite and its subsequent infectivity. Chymotrypsin and ovalbumin reduced the adsorption of reovirus to kaolinite and montmorillonite homoionic to sodium. Lysozyme did not reduce the adsorption of the virus to kaolinite, but it did reduce adsorption to montmorillonite. The proteins apparently competed with the reovirus for sites on the clay. As lysozyme does not adsorb to kaolinite by cation exchange, it did not inhibit the adsorption of reovirus to this clay. The amount of reovirus desorbed from lysozyme-coated montmorillonite was approximately 38% less (compared with the input population) than that from uncoated or chymotrypsin-coated montmorillonite after six washings with sterile distilled water. Chymotrypsin and lysozyme markedly decreased reovirus infectivity in distilled water, whereas infectivity of the virus was enhanced after recovery from an ovalbumin-distilled water-reovirus suspension (i.e., from the immiscible pelleted fraction plus supernatant). The results of these studies indicate that the persistence of reovirus in terrestrial and aquatic environments may vary with the type of organic matter and clay mineral with which the virus comes in contact.     

Effect of proteins on reovirus adsorption to clay minerals.

Organic matter in sewage, soil, and aquatic systems may enhance or inhibit the infectivity of viruses associated with particulates (e.g., clay minerals, sediments). The purpose of this investigation was to identify the mechanisms whereby organic matter, in the form of defined proteins, affects the adsorption of reovirus to the clay minerals kaolinite and montmorillonite and its subsequent infectivity. Chymotrypsin and ovalbumin reduced the adsorption of reovirus to kaolinite and montmorillonite homoionic to sodium. Lysozyme did not reduce the adsorption of the virus to kaolinite, but it did reduce adsorption to montmorillonite. The proteins apparently competed with the reovirus for sites on the clay. As lysozyme does not adsorb to kaolinite by cation exchange, it did not inhibit the adsorption of reovirus to this clay. The amount of reovirus desorbed from lysozyme-coated montmorillonite was approximately 38% less (compared with the input population) than that from uncoated or chymotrypsin-coated montmorillonite after six washings with sterile distilled water. Chymotrypsin and lysozyme markedly decreased reovirus infectivity in distilled water, whereas infectivity of the virus was enhanced after recovery from an ovalbumin-distilled water-reovirus suspension (i.e., from the immiscible pelleted fraction plus supernatant). The results of these studies indicate that the persistence of reovirus in terrestrial and aquatic environments may vary with the type of organic matter and clay mineral with which the virus comes in contact.     

Adsorption of urea by some Sudan soils

Summary Experiments were carried out to measure direct adsorption of urea in some Sudan soils and to compare two methods for controlling urea hydrolysis. All the soils examined showed some capacity to adsorb urea. Urea adsorption was related to both the exchange capacity and clay content; the exchange capacity giving higher correlation than the clay content. Both autoclaving and mercuric chloride treatments controlled hydrolysis almost completely. Autoclaving was preferred as the method of controlling hydrolysis in this work.     

Effect of varying Mg/Ca ratio and electrolyte concentration in the irrigation water on the soil properties and growth of wheat

This paper discusses the results of a pot experiment conducted to study the effect of irrigation waters having varying Mg/Ca ratio (2, 4, 8 and 16) and electrolyte concentration (20 and 80 meq/l) on the soil properties and growth of wheat crop in two different soils. The development of salinity in the soils generally increased at higher electrolyte concentration of the irrigation water, but it was of a greater magnitude in the heavy-textured black soil dominated by montmorillonite clay mineral than in the light-textured alluvial soil having illite type of clay mineral. The accumulation of soluble salts as a result of saline water irrigation was higher in the surface layer than in the subsurface layer in both soils. The adsorption of Na and Mg in the soils increased with an increase in the Mg/Ca ratio and electrolyte concentration of the irrigation water. These changes in soil properties were adequately reflected by the grain and dry matter yields of wheat crop, which showed a significant reduction with an increase in the Mg/Ca ratio and electrolyte concentration of the irrigation water. However, the effects of these treatments were more pronounced in the heavy black clay soil than in the alluvial soil. Thus, the role of Mg is different from that of Ca under the conditions used in the experiment.     

Status of copper in some calcareous and non-calcareous soils of Egypt

Summary To assess the status of copper in Egyptian soils, surface and subsurface soil samples were collected from various geographical regions of Egypt and of various genesis. The samples were analyzed for the total Cu, water-soluble plus exchangeable as well as the acid-extractable and EDTA-extractable Cu. The total Cu varied between 3.5 and 72.3 ppm. Less than 2% of this copper was in the soluble plus exchangeable form. The highest values of total and soluble plus exchangeable copper were found in the alluvial soils while the sandy soils had the least amounts. This was attributed to the high clay and organic matter content of the alluvial soils in addition to the dominance of montmorillonitic clay minerals in their fine fraction. The calcareous soils showed intermediate values of total and soluble plus exchangeable Cu due to their lower organic matter and clay mineral content. The clay mineralogy of these soils revealed the dominance of illitic and kaolinitic minerals which are relatively poor in Cu and other trace elements.Because of their relatively higher organic matter content, the alluvial soils had a large percentage (up to 43%) of their total Cu in the EDTA extractable form. The calcareous soils, on the other hand, had a large percentage (up to 52%) of their Cu in the acid-extractable form. The EDTA extractable Cu was correlated with the organic matter content of the soils. Since the pH of the EDTA extract was found to be dependent on the CaCO₃ content of the soils, it was suggested that the method be modified so that the final pH of the extract is constant for all soils.     

溶解性有机碳在红壤水稻土中的吸附及其影响因素

吸附作用是影响土壤中溶解性有机碳(DOC)迁移转化及生物有效性的重要反应过程,研究DOC在土壤中的吸附行为,对正确阐明土壤有机碳的循环和转化特征以及进行污染风险评估有重要意义.采用平衡法研究了红壤水稻土对DOC的吸附特征,并分析土壤有机质、粘粒含量及pH值与DOC吸附量之间的关系.结果表明,供试土壤对DOC的吸附等温线符合Freundlich和Linear方程.不同土壤对DOC的吸附能力有明显差异.在相同浓度下,DOC吸附量以第四纪红色粘土发育的低肥力水稻土最大,第三纪红砂岩风化物发育的低肥力水稻土次之,两种高肥力水稻土最小.土壤对DOC的吸附过程分为快、慢两个阶段,0-0.25 h内DOC的吸附速率最大,随着时间的推移,吸附速率渐小,2-4 h后基本达到吸附平衡.描述供试土壤对DOC吸附动力学过程的最优模型为一级扩散方程,其次为Elovich方程和抛物扩散方程.粘粒含量和有机质是影响土壤DOC吸附量的重要因素,随着粘粒含量的增加,有机质含量的降低,DOC的吸附量增大.     

Plant availability of applied and native boron in soils with diverse properties

Laboratory and greenhouse research was conducted to study effects of soil properties on the availability of native and applied B in 14 Virginia soils. Boron absorption could be described by the Langmuir equation in 12 of the 14 soils, and maximum B adsorption (Vmax) in these 12 soils ranged from 3.3 to 26.5 mg kg⁻¹. A multiple regression equation, −19.3+3.51 pH+0.048 clay content, accounted for 89.6% of the variation in Vmax for the 12 soils. Curvilinear relationships (α=0.01) occurred between B in corn (Zea mays L.) tissue from native B and hot-water soluble B, mannitol exchangeable B, and NH₄-acetate and Mehlich III extractable B. Among these four procedures, mannitol exchangeable B correlated most closely (r=0.923) with B in corn tissue from native B. From 0.4 to 13.5% of the applied B was absorbed by corn plants and translocated to shoots. Curvilinear relationships (α=0.01) occurred between B in corn tissue from applied B and soil clay content, NH₄-oxalate extractable Al and Fe, and acidified NH₂OH·HCl extractable Mn. It is evident from these relationships that soil clay and oxyhydroxides of Al, Fe, and Mn have an affinity to adsorb B in somewhat unavailable forms.     

Geophagy in chacma baboons: patterns of soil consumption by age class, sex, and reproductive state

Despite baboons' widespread distribution across Africa, geophagy among all subspecies has been poorly documented. We used video camera traps and soil analyses to investigate geophagy in chacma baboons (Papio cynocephalus ursinus) inhabiting the Western Cape of South Africa. During an 18‐month study, from August 2009 to January 2011, we continually monitored the largest and most frequently visited geophagy sites with camera traps for 545 days and captured soil consumption at one or more sites on 266 of those days (49%). In 3,500 baboon visits to geophagy sites, video camera traps captured 58.6 hr of geophagy. From these data, we evaluated site preference based on time spent consuming soil among these four geophagy sites. One hundred and seventy days of soil consumption data from the most frequently visited geophagy site allowed us to look for demographic trends in geophagy. Selected consumed soils from geophagy sites were analyzed for mineral, physical, and chemical properties. The baboons spent more time consuming white alkaline soils with high percentages of clay and fine silt, which contained higher concentrations of sodium than non‐white acidic soils that contained higher concentrations of iron. Our data indicate that pregnant chacma baboons spent more time consuming soil at monitored geophagy sites than baboons of any other age class, sex, or reproductive state. Based on analytical results, the soils consumed would be effective at alleviating gastrointestinal distress and possibly supplementing minerals for all age/sex classes, but potentially for different age/sex requirements. Am. J. Primatol. 74:48–57, 2012. © 2011 Wiley‐Liss, Inc.     

Observations of termitarium geophagy by Rylands’ bald-faced saki monkeys (<Emphasis Type="Italic">Pithecia rylandsi</Emphasis>) in Madre de Dios,Peru

Geophagy, or soil consumption, has been documented in diverse animal taxa, including many primates. Physiological functions such as mineral supplementation, detoxification of secondary compounds, and antacid properties are possible causes for this behavior. We report on observations of geophagy at arboreal termitaria by free-ranging Pithecia rylandsi at La Estación Biológica Los Amigos (EBLA) in Perú between 2008 and 2015. Characteristics of geophagy events, including saki monkey behavior at the termitaria, were recorded and geochemical analyses were conducted on consumed termitaria, nearby topsoils, and unvisited termitaria. We observed 76 feeding bouts at 26 different termitaria by two groups of P. rylandsi during 1125 observational hours (0.07 bouts/obs. h). Geophagy occurred throughout the year, but rates peaked in January during the rainy season. All age and sex classes visited both active and inactive mounds. Feeding bouts were brief (171 ± SD 154 s), and no differences were observed in time spent feeding at active or inactive termitaria. Analyses showed that consumed soils contained higher concentrations of phosphorous, potassium, calcium, and magnesium than did topsoil. Consumed soils also contained a higher total cation exchange capacity than topsoil. Our analysis of consumed versus control termitaria revealed no differences in their chemical composition. We discuss these results in the context of the two primary hypotheses proposed for geophagy in pitheciins: mineral supplementation and toxin adsorption. Our data are consistent with the interpretation that P. rylandsi consume soils from arboreal termitaria to aid in adsorption of toxins found in immature seeds, which are a year-round component of their diet.     

Insecticidal Activity of the Toxins from Bacillus thuringiensis subspecies kurstaki and tenebrionis Adsorbed and Bound on Pure and Soil Clays

The release of transgenic plants and microorganisms expressing truncated genes from various subspecies of Bacillus thuringiensis that encode active insecticidal toxins rather than inactive protoxins could result in the accumulation of these active proteins in soil, especially when bound on clays and other soil particles. Toxins from B. thuringiensis subsp. kurstaki and B. thuringiensis subsp. tenebrionis, either free or adsorbed at equilibrium or bound on pure clay minerals (montmorillonite or kaolinite) or on the clay size fraction of soil, were toxic to larvae of the tobacco hornworm (Manduca sexta) and the Colorado potato beetle (Leptinotarsa decemlineata), respectively. The 50% lethal concentrations (LC(inf50)) of free toxins from B. thuringiensis subsp. kurstaki were higher than those of both bound and adsorbed complexes of these toxins with clays, indicating that adsorption and binding of these toxins on clays increase their toxicity in diet bioassays. The LC(inf50) of the toxin from B. thuringiensis subsp. tenebrionis that was either free or adsorbed on montmorillonite were comparable, whereas the toxin bound on this clay had higher LC(inf50) and the toxin bound on kaolinite had lower LC(inf50) than when adsorbed on this clay. Results obtained with the clay size fraction separated from unamended soil or soil amended with montmorillonite or kaolinite were similar to those obtained with the respective pure clay minerals. Therefore, insecticidal activity of these toxins is retained and sometimes enhanced by adsorption and binding on clays.     

Clay minerals as a soil potassium reservoir: observation and quantification through X-ray diffraction

Potassium (K) is a major element for plant growth. The K⁺ ions fixed in soil 2:1 clay mineral interlayers contribute to plant K nutrition. Such clay minerals are most often the majority in temperate soils. Field and laboratory observations based on X-ray diffraction techniques suggest that 2:1 clay minerals behave as a K reservoir. The present work investigated this idea through data from a replicated long term fertilization experiment which allowed one to address the following questions: (1) Do fertilization treatments induce some modifications (as seen from X-ray diffraction measurements) on soil 2:1 clay mineralogy? (2) Are soil 2:1 clay mineral modifications related to soil K budget in the different plots? (3) Do fertilizer treatments modify clay Al, Si, Mg, Fe or K elemental content? (4) Are clay mineral modifications related to clay K content modifications? (5) Are clay mineral changes related to clay Al, Si, Mg or Fe content as well as those of K content? Our results showed that K fertilization treatments considered in the context of soil K budget are very significantly related to 2:1 soil clay mineralogy and clay K content. The 2:1 clay mineral modifications observed through X-ray measurements were quantitatively correlated with chemically analyzed clay K content. Clay K content modifications are independent from clay Al, Si, Mg or Fe contents. These results show that the soil chemical environment can modify interlayer site occupations (illite content) which suggests that high level accumulation of potassium can occur without any modification of the clay sheet structure. This study therefore validates the view of 2:1 clay minerals as a K reservoir easily quantifiable through X-ray observations.     

Geophagy by the bonnet macaques (Macaca radiata) of southern India: A preliminary analysis

Bonnet macaques (Macaca radiata) in the Marakkanam Reserved Forest of southern India consume termitaria soils. Samples from the ingested termite mounds are compared with samples taken from the surrounding uneaten soils in an attempt to determine why the termitaria soils are eaten. Particle size, clay and primary mineral composition, geochemistry, and scanning electron microscopic analyses are used to search for a possible explanation for geophagy among the bonnet macaques. Kaolin minerals abound throughout the Marakkanam soil sample suite. But the termitaria soils are distinguished by the presence of small amounts of smectite. An abundance of kaolin minerals in combination with small amounts of smectite strongly resembles the mineralogy ofeko, a traditional African remedy for stomach ailments, and Kaopectate™, a western anti-diarrhoeal preparation. The percentage of mature leaves and fruits ofAzadirachta indica consumed by the bonnet macaques is relatively high. Plant feeding deterrents, such as, acid detergent fibre (ADF) and the inherent nature of the fruits ofAzadirachta indica, when consumed in large quantities to act as a purgative, could cause gastrointestinal upsets and diarrhoea. At Marakkanam, bonnet macaques ingest termitaria earth that would act as a pharmaceutical agent to alleviate gastrointestinal upsets and control diarrhoea.