Diet and habitat use of two sympatric species of Philodryas (Colubridae), in south Brazil

2005 ◽  
Vol 26 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Otávio Marques ◽  
Paulo Hartmann

AbstractFeeding habits and habitat use of the colubrid snakes Philodryas olfersii and P. patagoniensis in southern Brazil are presented here. Philodryas olfersii and P. patagoniensis are sympatric in the study area and both dwell in open and forested areas. Specimens preserved in collections and observations of snakes in the field yielded the data. Both species are diet generalists, feeding on small vertebrates, mainly frogs. Philodryas patagoniensis has a broader diet, a less variable frequency of food items, and fed on heavier prey than P. olfersii. Seasonal variation in diet occurs in both species. The semiarboreal Philodryas olfersii is more slender and has a longer tail than the terrestrial P. patagoniensis, characters that may reflect differences in microhabitat use. There are a strong relationship between habitat use and frequency of a given food type. Differences in the use of food resources between P. olfersii and P. patagoniensis seem to reflect differences in foraging microhabitats used by each species.

2019 ◽  
Vol 14 (1) ◽  
pp. 1-12
Author(s):  
Lucas Porto ◽  
Ana Maria Rui

The crab-eating fox (Cerdocyon thous) and the Pampas fox (Lycalopex gymnocercus) are two canids with very similar food and habitat requirements, which live in sympatry across parts of their distributions. Here we describe the diet and habitat use of both canids in the Pampas biome. The study took place in southern Brazil from December 2012 to December 2013. Diet and habitat use analyses were based on fecal samples, footprints and direct visualizations. Diet overlap was measured using Pianka’s index, while habitat use was measured using presence records from three different environments; forests, edges and open areas. Both canids feed on invertebrates and vertebrates but have preferences for fruits, especially Syagrus romanzoffiana. Pianka’s index showed a high overlap of their diets throughout the year, with the exception of autumn. Regarding habitat use, C. thous preferred to inhabit forested areas while L. gymnocercus was more active in open areas. Our results showed that fruits were the most consumed food item in the Pampas biome. Our findings suggest that habitat use by these two canids is affected by seasonal variation in fruit abundance, but other factors, such as parental care, should be taken into account when explaining how they behave throughout the year.


2000 ◽  
Vol 43 (5) ◽  
pp. 527-531 ◽  
Author(s):  
José Marcelo R. Aranha ◽  
José Henrique C. Gomes ◽  
Fábio N. O. Fogaça

The feeding strategy of Characidium lanei and C. pterostictum was studied in the "Cabral" stream, a coastal stream of the Atlantic Forest, in southern Brazil. The samples were taken using electric fishing between March/95 and February/96. We studied about 15 stomach contents for each species in each season of the year. The stomach contents of the studied species were composed of 39 different food items, 28 in C. lanei and 24 in C. pterostictum. Chironomidae larvae and Ephemeroptera nymph were the most important items for C. lanei, except in the summer when Acarina and not identified Arthropoda were the most important items. Chironomidae and Simulidae larvae were the most important items in C. pterostictum. These results indicated an insectivorous habits and opportunist feeding strategy to C. lanei and C. pterostictum with several items rare or not very frequent.


2006 ◽  
Vol 84 (6) ◽  
pp. 877-886 ◽  
Author(s):  
M.A. Johnson ◽  
R. Kirby ◽  
S. Wang ◽  
J.B. Losos

Geographic variation in habitat availability may drive geographic variation in a species’ habitat use; alternatively, species adapted to particular habitat characteristics may use a habitat regardless of its availability within an environment. In this study, we investigated habitat use of two sympatric species of Anolis lizards that are morphologically specialized to use different microhabitats. We examined variation in microhabitat use and availability among four distinct forest types. In each forest type, we quantified available microhabitats (i.e., perch diameter, angle of inclination, and visibility), as well as microhabitats actually used by each species. We found that species consistently differed in microhabitat use, corresponding to each species’ morphological specializations. However, microhabitat use of both species varied among sites. This variation in Anolis gundlachi Peters, 1876 reflected differences in microhabitat availability, while the variation in Anolis krugi Peters, 1876 resulted from differential microhabitat selectivity. These results indicate that both habitat availability and habitat preferences must be examined in multiple localities for a species to understand the causes of variation in its habitat use.


2009 ◽  
Vol 7 (2) ◽  
pp. 257-266 ◽  
Author(s):  
Luciano Lazzarini Wolff ◽  
Vinícius Abilhoa ◽  
Flavia Sant'Anna Rios ◽  
Lucélia Donatti

This study described the feeding habits of the characin Astyanax aff. fasciatus. The diet compositions of specimens from two sites (A and B) on a river in Southern Brazil were compared according to the size of individuals and seasonal period. The collections were performed monthly from March 2005 to February 2006, where the stomach contents of 290 specimens were assessed. Food items for A. aff. fasciatus were basically composed of plants and insects, especially leaf fragments, seeds, fruits, filamentous algae, aquatic and terrestrial insects and insect fragments. At site A, the most common items were insect and plant fragments. Conversely at site B, plant fragments were more representative. In general, all items of animal origin showed the highest feeding index values at site A, whereas at site B detritus and grass items were more abundant. The composition of items varied seasonally, with higher diversity of items being recorded during the spring at both sites. Smaller individuals preferred items of animal origin, while the larger ones consumed mainly items of plant origin. According to its size, A. aff. fasciatus in this study may be considered a species with insectivorous tendencies when immature or herbivorous tendencies when adult. Nevertheless, its feeding habits may be flexible according to resource availability, showing wide ontogenetic, besides spatial and temporal variation.


2005 ◽  
Vol 39 (4) ◽  
pp. 664-667 ◽  
Author(s):  
Marília T. Hartmann ◽  
Paulo A. Hartmann ◽  
Sonia Z. Cechin ◽  
Marcio Martins

2014 ◽  
Vol 86 (2) ◽  
pp. 807-819 ◽  
Author(s):  
MAURY S.L. ABREU ◽  
LARISSA R. DE OLIVEIRA

Despite the advances in the techniques for researching arboreal small mammals, detailed ecological data, such as habitat use patterns, are practically nonexistent for many species. Using 150 live-traps installed on the ground, understory (1.0-5.0m) and canopy (>5.0m) we investigated patterns of arboreal and terrestrial space use by small mammals in an Araucaria Forest in southern Brazil (29°29′08″S; 50°12′26″W). We also measured 19 microhabitat variables that could potentially influence the abundance of such mammals on each trap station. The results indicated that Akodon montensis and A. serrensis were mainly terrestrial. Delomys dorsalis was also terrestrial, but it also used understory (17.24% of captures). Juliomys sp. and Gracilinanus microtarsus were the most arboreal small mammals recorded. A. montensis was associated with dense vegetation, while A. serrensis selected positively opened areas. Juliomys sp. and G. microtarsus were associated to microhabitat variables related to the access and movement within the canopy. Moreover, bromeliads on arboreal layer were an important factor for these two arboreal species. This is the first study to report microhabitat associations by Juliomys sp. and A. serrensis, and we demonstrated that vertical stratification and microhabitat use were both synergic mechanisms to determine habitat use by small mammals on the Araucaria Forest of southern Brazil.


2010 ◽  
Vol 8 (4) ◽  
pp. 813-818 ◽  
Author(s):  
Vinícius Abilhoa ◽  
Jean Ricardo Simões Vitule ◽  
Hugo Bornatowski

Feeding habits of the killifish Rivulus luelingi collected in a black water stream of the Coastal Atlantic Rainforest in southern Brazil were investigated. Eight samplings were made between April 2003 and January 2004. The diet, assessed through a similarity matrix with the estimated contribution values of food items, included microcrustaceans, aquatic immature insects (larvae and pupae), aquatic adult insects, terrestrial insects, insect fragments, spiders, and plant fragments. Differences in the diet according to temporal variations (months) were registered, but changes related with size classes evaluated and high/low precipitation period were not observed. The species presented an insectivorous feeding habit, and its diet in the studied stream was composed of autochthonous (mainly aquatic immature insects) and allochthonous (mainly insect fragments) material.


Author(s):  
Daniel Danilewicz ◽  
Eduardo R. Secchi ◽  
Paulo H. Ott ◽  
Ignacio B. Moreno ◽  
Manuela Bassoi ◽  
...  

The patterns of habitat use by the franciscana dolphins (Pontoporia blainvillei) along its distribution are poorly known. This study investigates the patterns of habitat use with respect to depth for 181 individuals of different age, size, gender and reproductive condition off Rio Grande do Sul, southern Brazil. The results reveal that franciscanas are very homogeneously distributed according to depth. Individuals from all lengths utilize nearly the entire range of depths of the surveyed area. Larger or older animals do not use deeper waters than younger animals, indicating that body size and age are not limiting factors for franciscanas that occupy deeper or offshore waters. Gestation seems to not cause a change in the distribution of females. Although the sex-ratio of the overall data did not vary from 1:1 in different depth intervals, a small-scale comparison between the northern and southern coast demonstrated the existence of some kind of sexual segregation. Franciscana by-catch in Rio Grande do Sul is not sustainable and it is agreed that management procedures are needed. Nevertheless, the available data on species distribution do not allow the designing of a protected area in order to minimize the by-catches of a particular sex/reproductive class.


2001 ◽  
Vol 61 (1) ◽  
pp. 55-61 ◽  
Author(s):  
A. L. V. ANDRADE ◽  
M. C. PINEDO ◽  
A. S. BARRETO

The gastrointestinal tract of 14 false killer whales, 6 males and 8 females, stranded in June 1995 in southern Brazil, with total standard lengths from 338 to 507 cm, were analysed for endoparasites and food items. A pregnant female had a male foetus of 77.5 cm. Parasites were found in all 14 false killer whales. The nematode Anisakis simplex (Rudolphi, 1809) was found in the stomach of 57% of the animals and the acanthocephalan Bolbosoma capitatum (Linstow, 1889) Porta, 1908 was present in the intestine of all specimens and showed densities up to 600 m-1. An unidentified cestode (Tethrabothridae) was found also in the intestines of 14% of the individuals. The high infections of B. capitatum and A. simplex were not directly related with the cause of death. In the stomachs of four females, beaks of at least eight specimens of the oceanic and epipelagic species Ommastrephes bartramii (Lesueur, 1821) were found, with mantle lengths ranging from 189.8 to 360.9 mm. The distribution of O. bartramii in the coast of Rio Grande do Sul is consistent with false killer whales feeding in continental shelf waters.


2014 ◽  
Vol 74 (4) ◽  
pp. 821-827 ◽  
Author(s):  
U Wischhoff ◽  
F Marques-Santos ◽  
M Rodrigues

The Cinereous Warbling-finch Poospiza cinerea is a globally vulnerable Emberizidae passerine, patchily distributed and rare in the open savannah of central South America. Attributes of rare species include niche specificity such as feeding habits. To verify possible niche specialization in this species we aimed to describe its foraging habits related to substrate use, foraging and substrate height, attack maneuvers, and consumed food items. We monitored two groups at two study sites and sampled foraging events with intervals of 15 minutes. The substrates used in greater frequency were foliage and reproductive organs. Foraging and substrate height varied widely with study area. The attack maneuver adopted in greater frequency was glean. Most food items attacked were small invertebrates. Big invertebrates included Lepidoptera, Hemiptera, Coleoptera, Hymenoptera and Orthoptera. Poospiza cinerea was also recorded foraging in mixed bird flocks with seven other species. The generalist foraging behavior of the species cannot be associate to its rarity.


Sign in / Sign up

Export Citation Format

Share Document