Seasonal diet shifts of seven fish species in an Atlantic rainforest stream in Southeastern Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The diet of bats from Southeastern Brazil: the relation to echolocation and foraging behaviour

In this study the incidence of moths and beetles was examined from feces samples of bats that use different foraging behaviors. Twenty sites around the Fazenda Intervales, a Field Research Station located in São Paulo State, in southeastern Brazil were sampled. Feces were collected from bats caught in mist nets, Turtle Traps or hand nets and, in one case, from beneath a roost. Feces samples were taken from six species of bats: Micronycteris megalotis (Gray, 1842), Mimon bennettii (Gray, 1838), Furipterus horrens (F. Cuvier, 1828), Myotis riparius Handley, 1960, Myotis ruber (E. Geoffroy, 1806) and Histiotus velalus (I. Geoffroy, 1824). To record and describe the frequencies dominating bat echolocation calls, an Anabat II bat detector coupled with an Anabat ZCA interfaces and DOS laptop computers were used. The data show that Furipterus horrens feeds extensively on moths, as predicted from the features of its echolocation calls. Gleaning bats, whose echolocation calls are much less conspicuous to moths take a wide range of insect (and other) prey.

Abundance, habitat use and diet of Callicebus nigrifrons Spix (Primates, Pitheciidae) in Cantareira State Park, São Paulo, Brazil

Entre abril de 2005 e maio de 2006, através de censos seguindo os pressupostos da metodologia de transecção linear, foram estimadas a densidade populacional e abundância de Callicebus nigrifrons Spix, 1823 (Pitheciidae) no Parque Estadual da Cantareira, Estado de São Paulo, Sudeste do Brasil (23°23'42S, 46°35'27W). Com um esforço amostral de 275,8 km de censos, os sauás foram a segunda espécie de primata mais abundante, apresentando um índice de abundância de 1,4 grupos para cada 10 km percorridos e uma estimativa de densidade de 12,21 ind./km² (variando de 8,45 a 17,63 ind./km²). A coleta de dados auxiliares durante os censos possibilitou a verificação da dieta e uso do hábitat pelos grupos de Callicebus, e os resultados evidenciaram uma relativa adaptabilidade à ambientes perturbados.

Uranium levels in the diet of São Paulo City residents

Natural levels of uranium in the diet of São Paulo City residents were studied, and radionuclide concentrations were measured by the fission track method on samples of typical adult food items. This information was used to evaluate the daily intake of uranium in individuals living in São Paulo City which is, according to our findings, around 0.97 mu g U/day. Using the ICRP Uranium-model, we estimated the uranium accumulation and committed doses in some tissues and organs, as function of time. We compared the output of the ICRP uranium biokinetic model, tailored for the conditions prevailing in São Paulo, with experimental data from other localities. Such comparison was possible by means of a simple method we developed, which allows normalization among experimental results from different regions where distinct values of chronic daily intake are observed. (c) 2006 Elsevier Ltd. All rights reserved.

Calcium bioavailability from the kale (Brassica-oleracea) consumed as a complement of a basal rice and bean diet

The bioavailability of calcium from the kale (Brassica oleracea var. acephala) consumed as a complement of a basal rice and bean diet was studied. Three groups of diets, two controls and one experimental were fed to Wistar female rats. The protein source of the first control was casein and of the second, a mixture of bean and rice. To both groups, graded levels of CaCO3 were added. The experimental diet was similar to the second control, except that CaCO3 was substituted for kale supplying the same amount of calcio. At 35 days of experimental period, they were killed and the calcium and phosphorus were determined in the right femur. The results indicated that the calcium from the kale is better utilized than that of the CaCO3. There was no significant difference in the concentration of calcium in the soft tissues studied among three dietary groups. Considering the high concentration and availability of calcium from the kale its consumption as a complement of the basal rice and bean diet may be recommended as a cheap and good source of this mineral.

DIET OF THE BROWN HOWLER MONKEY ALOUATTA-FUSCA IN A FOREST FRAGMENT IN SOUTHEASTERN BRAZIL

The diet of the brown howler monkey Alouatta fusca in a 250 ha forest fragment in southeastern Brazil was studied for 42 consecutive months. The howlers were observed eating in 366 feeding records (one group or a monkey eating a single plant) of 52 plant species. Twenty three percent of the leaves and 52 % of the flowers in the howler's diet came from lianas. Eighteen fruit species were recorded as being dispersed by howlers and seeds of two liana species were eaten. In small forest fragments where most large specialized frugivores are absent howlers may be the main seed disperser of large fruits.

LOW-PROTEIN DIET IMPAIRS GLUCOSE-INDUCED INSULIN-SECRETION FROM AND CA-45 UPTAKE BY PANCREATIC RAT ISLETS

Glucose-induced insulin secretion rom and Ca-45 uptake by isolated pancreatic islets, derived from rats fed with normal (NPD) or low protein diet (LPD), were studied. Insulin secretion from both types of islets in response to increasing concentrations of glucose followed an S-shaped pattern. However, basal secretion observed at substimulatory concentrations of glucose (0-5.6 mM), as well as maximal release, obtained at 16.7 mM or higher glucose concentrations were significantly reduced in islets from LPD. Furthermore, in LPD rat islets, the dose-response curve to glucose was clearly shifted to the right compared with NPD islets, with the half-maximal response occurring at 8.5 and 14.4 mM glucose for NPD and LPD islets, respectively. In islets from NPD rats, the Ca-45 content, after 5 or 90 min in the presence of 8.3 mM glucose, was higher than that observed for islets kept at 2.8 mM glucose and increased further at 16.7 mM glucose. After 5 min of incubation, the Ca-45 uptake by LPD islets in the presence of 8.3 mM glucose was slightly higher than basal values (2.8 mM glucose); however, no further increase in the Ca-45 uptake was noticed at 16.7 mM glucose. In LPD islets a significant increase in Ca-45 uptake over basal values was registered only at 16.7 mM glucose, after 90 min of incubation. These data indicate that the poor secretary response to glucose observed in islets from LPD rats may be related to a defect in the ability of glucose to increase Ca2+ uptake and/or to reduce Ca2+ efflux from beta-cells.

THE EFFECT OF RECENT DIET ON PREY ODOR DISCRIMINATION BY JUVENILE TEGU LIZARD, TUPINAMBIS-TEGUIXIN (SAURIA, TEIIDAE)

Teiid lizards are intesive foragers supposed to rely lagerly on chemoreception for prey detection, an ability that can be modified by previous feeding experiences. We investigated the ability of juvenile lizards, Tupinambis teguixin, in discriminate prey from non-prey odors as well as the effects of recent diet on these ability. Tegu lizards were able to discriminate prey odors and this ability probably is inate. The effect of recent diet was analysed through optimal foraging models and our results does not support in a broad sense the predictions made by theoretical models.

Small mammals in the diet of barn owls (Tyto alba) in agroecosystems of southern Brazil

We studied the diet of the Barn Owl (Tyto alba) in an agricultural area of southern Brazil (29degrees36'S, 52degrees11'W), based on analysis of regurgitated remains. The results clearly showed that the diet of the Barn Owl reflects the human impact on its habitat. The cosmopolitan house mouse (Mus musculus) was the most preyed upon small mammal (81.9%) and the most important in terms of the Barn Owl ingested biomass (69%). This rodent, due to its small size, is also responsible for the relatively low me-an weight off small mammal prey in the owl diet (19.6 g). In southern Brazilian agroecosystems, the Barn Owl probably feeds mainly on mice due to their great abundance in crop fields and grain storage areas of the region.

The use of extruded feed in fish food

In our country, the intensive culture of fish has been making progress due to the availability of extruded rations, which are characterized by the way they have been formulated to assist the nutritional demands of the tropical species and for facilitating a better practice of alimentary handling. This process checks the extruded product density and the desirable physical/chemical aspects to a diet that should be handled in the water, the critical factor of this activity. It is important to emphasize that this product stays to the surface of the water, facilitates the consumption control and the observation of the general aspects of the school of fish, as well as guaranteeing that no deterioration of the physical/chemical characteristics of the water occurs. The floating characteristic of the extruded ration is preferable for farmers because most of the tropical species feed at the surface of the water. In some cases, in the function of the alimentary habit, the thermal conditions of the water and the handling system produce granules with different densities. This is due to the humidity and the applied cooking heat, which modifies the time of hydration, and consequently the ability to float. To establish the physical presentation idea for a ration for tropical fishes, it is necessary that the pellets come in sizes, textures, humidities and densities in order to allow for the different phases of the lives of the fishes. This ration should be the result of characteristics of the species, such as the anatomophysiologics particularities, alimentary habits, digestive capacity and alimentary behavior. Only in this way is it possible to offer to those fishes a ration whose nutritious value and physical presentation facilitate the best biological and economic answers.Those aspects need to be reviewed because the tropical species that are cultivated in our country present selective behavior in relation to the size of the pellet. Generally, this has access to the digestive system without waste; the digestibility, therefore, is dependent upon the size of the particles and the physical aspects of the pellets. They should still consider that those granules could be less abrasive and softer. The extruded rations available in the national market present a qualitative reference to its proteic level, whose consequence allows us to infer that those are overestimated for the final phase of those fishes. Thus, the final cost of production is made unfeasible. In this point of view of the development of the national fish culture, and the growing adoption of the intensive system of production, it can link that such progress is a function of the availability of the rations in the extruded form. Although this technique of processing of rations has revolutionized the market in such a way that has been seen as preferable for farmers, some feel that there is a lack of products best suited for the initial phases of fingerlings production.