GALETTI, M. DONATTI, C.I.; PIRES, A.S.; GUIMARÃES JR., P.R.; JORDANO, P. 2006. Seed survival and dispersal of an endemic Atlantic forest palm: the combined effects of defaunation and forest fragmentation. Botanical Journal of the Linnean Society 151:141-149.
Abstract. About 45 palm species occur in the Atlantic forest of Brazil, and most of them are affected by loss of seed dispersers resulting from forest fragmentation and hunting. Here we report the effects of habitat loss and defaunation on the seed dispersal system of an endemic palm, Astrocaryum aculeatissimum. We evaluated seed removal, insect and rodent seed predation, and scatter-hoarding in nine sites, ranging from 19 ha to 79 000 ha. We report the seedling, juvenile and adult palm densities in this range of sites. Endocarps remaining beneath the parent palm had a higher probability of being preyed upon by insects in small, mostly fragmented and more defaunated sites. The frequency of successful seed removal, scatter-hoarding and consumption by rodents increased in the larger, less defaunated sites. Successful removal and dispersal collapsed in small (< 1000 ha), highly defaunated sites and frequently resulted in low densities of both seedlings and juveniles. Our results indicate that a large fraction of Atlantic forest palms that rely on scatter-hoarding rodents may become regionally extinct due to forest fragmentation and defaunation. Current management practices including palm extraction and hunting pressure have a lasting effect on Atlantic forest palm regeneration by severely limiting successful recruitment of prereproductive individuals.
Mostrando postagens com marcador Atlantic forest. Mostrar todas as postagens
Mostrando postagens com marcador Atlantic forest. Mostrar todas as postagens
sábado, 3 de outubro de 2015
sábado, 13 de junho de 2015
Primeiro registro documentado de Holochilus brasiliensis (Desmarest, 1819) e Calomys laucha (G. Fischer, 1814) no estado de Santa Catarina, sul do Brasil
PETERS, F.B.; ROTH, P.R.O.; CHRISTOFF, A.U. 2013. Primeiro registro documentado de Holochilus brasiliensis (Desmarest, 1819) e Calomys laucha (G. Fischer, 1814) no estado de Santa Catarina, sul do Brasil. Biotemas 26(3):177-184. http://dx.doi.org/10.5007/2175-7925.2013v26n3p177
Abstract. First documented record of Holochilus brasiliensis (Desmarest, 1819) and Calomys laucha (G. Fischer, 1814) in the state of Santa Catarina, south Brazil. Studies on the richness of small mammals in the Brazilian South Region are recent and point out the need for using varied methods. This way, this paper contributes to knowledge on the fauna of small sigmodontinae rodents in Santa Catarina, including Holochilus brasiliensis and Calomys laucha in the list of species with confirmed occurrence in this state. The records of H. brasiliensis refer to Laguna (n = 2) and Timbe do Sul (n = 1). In turn, C. laucha presents 23 records from Capinzal. The entire material is represented by skull fragments from owl pellets samples collected from nests and feeding perches of the Tyto alba.
Abstract. First documented record of Holochilus brasiliensis (Desmarest, 1819) and Calomys laucha (G. Fischer, 1814) in the state of Santa Catarina, south Brazil. Studies on the richness of small mammals in the Brazilian South Region are recent and point out the need for using varied methods. This way, this paper contributes to knowledge on the fauna of small sigmodontinae rodents in Santa Catarina, including Holochilus brasiliensis and Calomys laucha in the list of species with confirmed occurrence in this state. The records of H. brasiliensis refer to Laguna (n = 2) and Timbe do Sul (n = 1). In turn, C. laucha presents 23 records from Capinzal. The entire material is represented by skull fragments from owl pellets samples collected from nests and feeding perches of the Tyto alba.
sábado, 28 de março de 2015
Medium and large-sized mammals of the Reserva Ecológica de Guapiaçú, Cachoeira de Macacu, RJ
CARVALHO, I.D.; OLIVEIRA, R.; PIRES, A.S. 2014. Medium and large-sized mammals of the Reserva Ecológica de Guapiaçú, Cachoeira de Macacu, RJ. Biota Neotropica 14(3):1-9.
Abstract: Medium and large-sized terrestrial mammals develop important functions in ecosystems maintenance. However, this group is the most vulnerable to local extinctions, through habitat loss or hunting. This study inventoried the community of medium and large mammals in the Reserva Ecológica de Guapiaçú (REGUA), Cachoeiras de Macacu, RJ, providing data on species composition, richness and abundance. Species were registered through the use of camera traps, sign survey and visual encounters on pre-existing trails and roads. The study was conducted from January to October 2012, with each month considered as a sample unit. An effort of 1568 cameras-day and 120 km traveled, resulted on 302 records of 22 species of medium and large-sized mammals, belonging to eight orders. This value corresponds to more than three-quarters of the richness described from this group in the Atlantic Forest of Rio de Janeiro state. Five species are under some level of regional, national or global threat. Three game species, Pecari tajacu, Cuniculus paca and Dasyprocta leporina were abundant in the area. The observed richness was comparable to that found in other studies conducted in rain forests. Thus, for its high number of species, including those under some degree of threat, we conclude that REGUA is an important area to mammal conservation, especially in the Atlantic Forest of Rio de Janeiro state.
Abstract: Medium and large-sized terrestrial mammals develop important functions in ecosystems maintenance. However, this group is the most vulnerable to local extinctions, through habitat loss or hunting. This study inventoried the community of medium and large mammals in the Reserva Ecológica de Guapiaçú (REGUA), Cachoeiras de Macacu, RJ, providing data on species composition, richness and abundance. Species were registered through the use of camera traps, sign survey and visual encounters on pre-existing trails and roads. The study was conducted from January to October 2012, with each month considered as a sample unit. An effort of 1568 cameras-day and 120 km traveled, resulted on 302 records of 22 species of medium and large-sized mammals, belonging to eight orders. This value corresponds to more than three-quarters of the richness described from this group in the Atlantic Forest of Rio de Janeiro state. Five species are under some level of regional, national or global threat. Three game species, Pecari tajacu, Cuniculus paca and Dasyprocta leporina were abundant in the area. The observed richness was comparable to that found in other studies conducted in rain forests. Thus, for its high number of species, including those under some degree of threat, we conclude that REGUA is an important area to mammal conservation, especially in the Atlantic Forest of Rio de Janeiro state.
sábado, 22 de março de 2014
Bats (Mammalia: Chiroptera) in native and reforested areas in Rancho Alegre, Paraná, Brazil
GALLO, P.H.; REIS, N.R.; ANDRADE, F.R. 2010. Bats (Mammalia: Chiroptera) in native and reforested areas in Rancho Alegre, Paraná, Brazil. Revista de Biología Tropical 58(4):1311-1322.
Abstract. Generally, natural environments have been transformed into small forest remnants, with the consequent habitat loss and species extinction. The North Paraná State is not an exception, since only 2 to 4% of the original ecosystem occurs in small fragments of Stational Semidecidual Forest. We studied the species richness and abundance of bats in two forest fragments from the Fazenda Congonhas, in Rancho Alegre city, Paraná State, Brazil. Four samplings were undertaken in a legally protected native area (107.8 ha) and in a reforested area (11.8 ha) between April 2007 and March 2008. Samplings began at nightfall and lasted six hours, during two consecutive nights in each location. The individuals were captured using eight mist nets, with the same capture effort in both environments. A total of 397 individuals, 14 species and 10 genera were captured in the native area; while in the reforested area, 105 individuals, six species and four genera. Artibeus lituratus was the most common species in both fragments (n= 328, 65.3%), followed by Artibeus fimbriatus (n= 44, 8.8%) and Artibeus jamaicensis (n= 30, 6.0%). Other species including Platyrrhinus lineatus, Carollia perspicillata, Sturnira lilium, Chrotopterus auritus, Desmodus rotundus, Michronycteris megalotis, Phyllostomus hastatus, Phyllostomus discolor, Myoti levis, Myotis nigricans and Lasiurus blossevillii, accounted for 19.9% of the captures. The native area presented higher values of species richness (S=14) and diversity (H’=1.4802) in comparison to the reforested area (S=6, H’=0.57015). The t-test evidenced a significant difference between diversity among the sites (t=7.1075). Chao 1 index indicated that the sampling effort recorded approximately 78% from the total species richness for the native area and 75% for the reforested area. Therefore, the preservation of the forest fragment is essential since it provides habitat for a diverse community of bats. Forest management and reforestation actions may prevent drastic changes in the microclimate of neighboring areas within the forest fragment, and could allow the occupation of available niches in the area, by opportunistic and generalist species.
Abstract. Generally, natural environments have been transformed into small forest remnants, with the consequent habitat loss and species extinction. The North Paraná State is not an exception, since only 2 to 4% of the original ecosystem occurs in small fragments of Stational Semidecidual Forest. We studied the species richness and abundance of bats in two forest fragments from the Fazenda Congonhas, in Rancho Alegre city, Paraná State, Brazil. Four samplings were undertaken in a legally protected native area (107.8 ha) and in a reforested area (11.8 ha) between April 2007 and March 2008. Samplings began at nightfall and lasted six hours, during two consecutive nights in each location. The individuals were captured using eight mist nets, with the same capture effort in both environments. A total of 397 individuals, 14 species and 10 genera were captured in the native area; while in the reforested area, 105 individuals, six species and four genera. Artibeus lituratus was the most common species in both fragments (n= 328, 65.3%), followed by Artibeus fimbriatus (n= 44, 8.8%) and Artibeus jamaicensis (n= 30, 6.0%). Other species including Platyrrhinus lineatus, Carollia perspicillata, Sturnira lilium, Chrotopterus auritus, Desmodus rotundus, Michronycteris megalotis, Phyllostomus hastatus, Phyllostomus discolor, Myoti levis, Myotis nigricans and Lasiurus blossevillii, accounted for 19.9% of the captures. The native area presented higher values of species richness (S=14) and diversity (H’=1.4802) in comparison to the reforested area (S=6, H’=0.57015). The t-test evidenced a significant difference between diversity among the sites (t=7.1075). Chao 1 index indicated that the sampling effort recorded approximately 78% from the total species richness for the native area and 75% for the reforested area. Therefore, the preservation of the forest fragment is essential since it provides habitat for a diverse community of bats. Forest management and reforestation actions may prevent drastic changes in the microclimate of neighboring areas within the forest fragment, and could allow the occupation of available niches in the area, by opportunistic and generalist species.
sábado, 22 de fevereiro de 2014
Effects of fragmentation of the Atlantic forest on mammal communities in south-eastern Brazil
CHIARELLO, A.G. 1999. Effects of fragmentation of the Atlantic forest on mammal communities in south-eastern Brazil. Biological Conservation 89:71-82.
Abstract. Six Atlantic forest reserves, two large (c. 20,000 ha each), two medium-sized (c. 2,000 ha each) and two small (c. 200 ha each), located in northern Espírito Santo, south-eastern Brazil were censured for mammals from October 1994 to April 1996. Diurnal and nocturnal line-transect sampling was used for censusing mammals > 1 kg body weight, and the relative abundance of species in the six fragments was compared. The number of mammal species recorded in the reserves was strongly related to the forest area, the richest community being recorded in the two large reserves and the poorest in the two small reserves. The large reserves had a structurally more complex community, with top predators, large, terrestrial frugivores and large myrmecophages. The mammal community of the small and the medium-sized reserves was impoverished and less complex. Frugivores were numerically predominant in both large and medium-sized reserves, whereas herbivores dominated the mammal community of the small reserves, mainly through the absence of agoutis Dasyprocta leporina and the high density of maned sloth Bradypus torquatus in the two small reserves. The lack of predators and the proliferation of secondary vegetation and lianas throughout the small reserves are probably the main causes for the success of arboreal folivores there. Illegal hunting was found to reduce the encounter rates of mostly large, terrestrial frugivores such as agoutis, pacas Agouti paca, peccaries Pecari tajacu and Tayassu pecari and deer Mazama spp., and is contributing to keep the population of the surviving species low.
Abstract. Six Atlantic forest reserves, two large (c. 20,000 ha each), two medium-sized (c. 2,000 ha each) and two small (c. 200 ha each), located in northern Espírito Santo, south-eastern Brazil were censured for mammals from October 1994 to April 1996. Diurnal and nocturnal line-transect sampling was used for censusing mammals > 1 kg body weight, and the relative abundance of species in the six fragments was compared. The number of mammal species recorded in the reserves was strongly related to the forest area, the richest community being recorded in the two large reserves and the poorest in the two small reserves. The large reserves had a structurally more complex community, with top predators, large, terrestrial frugivores and large myrmecophages. The mammal community of the small and the medium-sized reserves was impoverished and less complex. Frugivores were numerically predominant in both large and medium-sized reserves, whereas herbivores dominated the mammal community of the small reserves, mainly through the absence of agoutis Dasyprocta leporina and the high density of maned sloth Bradypus torquatus in the two small reserves. The lack of predators and the proliferation of secondary vegetation and lianas throughout the small reserves are probably the main causes for the success of arboreal folivores there. Illegal hunting was found to reduce the encounter rates of mostly large, terrestrial frugivores such as agoutis, pacas Agouti paca, peccaries Pecari tajacu and Tayassu pecari and deer Mazama spp., and is contributing to keep the population of the surviving species low.
sábado, 1 de fevereiro de 2014
Efficiency of box-traps and leg-hold traps with several bait types for capturing small carnivores (Mammalia) in a disturbed area of Southeastern Brazil
MICHALSKI, F.; CRAWSHAW JR., P.G.; OLIVEIRA, T.G.; FABIÁN, M.E. 2007. Efficiency of box-traps and leg-hold traps with several bait types for capturing small carnivores (Mammalia) in a disturbed area of Southeastern Brazil. Revista de Biología Tropical 55(1):315-320.
Abstract. Capturing small carnivores is often necessary for obtaining key ecological data. We compared the efficiency of box and leg-hold traps, using live and dead bait, to capture six carnivore species (Herpailurus yagouaroundi (É. Geoffroyi, 1803), Leopardus tigrinus (Schreber, 1775), Nasua nasua (Linnaeus, 1766), Cerdocyon thous (Linnaeus, 1766), Eira barbara (Linnaeus, 1758), and Galictis cuja (Molina, 1782)). The use of leg-hold traps significantly increased the capture rate of carnivores (5.77%) and non-target species (non-carnivores, 11.54%). Dead bait significantly attracted more non-carnivores than carnivores and live bait was more efficient for capturing carnivores (2.56%) than non-carnivores (0.77%). Both box and leg-hold traps caused some minor injuries (swelling and claw loss). We provide recommendations for the ethical use of these trap and bait types.
Abstract. Capturing small carnivores is often necessary for obtaining key ecological data. We compared the efficiency of box and leg-hold traps, using live and dead bait, to capture six carnivore species (Herpailurus yagouaroundi (É. Geoffroyi, 1803), Leopardus tigrinus (Schreber, 1775), Nasua nasua (Linnaeus, 1766), Cerdocyon thous (Linnaeus, 1766), Eira barbara (Linnaeus, 1758), and Galictis cuja (Molina, 1782)). The use of leg-hold traps significantly increased the capture rate of carnivores (5.77%) and non-target species (non-carnivores, 11.54%). Dead bait significantly attracted more non-carnivores than carnivores and live bait was more efficient for capturing carnivores (2.56%) than non-carnivores (0.77%). Both box and leg-hold traps caused some minor injuries (swelling and claw loss). We provide recommendations for the ethical use of these trap and bait types.
sábado, 12 de outubro de 2013
Microhabitat of small mammals at ground and understorey levels in a deciduous, southern Atlantic Forest
MELO, G.L.; MIOTTO, B.; PERES, B.; CÁCERES, N.C. 2013. Microhabitat of small mammals at ground and understorey levels in a deciduous, southern Atlantic Forest. Anais da Academia Brasileira de Ciências 85(2):727-736.
Abstract. Each animal species selects specific microhabitats for protection, foraging, or micro-climate. To understand the distribution patterns of small mammals on the ground and in the understorey, we investigated the use of microhabitats by small mammals in a deciduous forest of southern Brazil. Ten trap stations with seven capture points were used to sample the following microhabitats: liana, fallen log, ground litter, terrestrial ferns, simple-trunk tree, forked tree, and Piper sp. shrubs. Seven field phases were conducted, each for eight consecutive days, from September 2006 through January 2008. Four species of rodents (Akodon montensis, Sooretamys angouya, Oligoryzomys nigripes and Mus musculus) and two species of marsupials (Didelphis albiventris and Gracilinanus microtarsus) were captured. Captured species presented significant differences on their microhabitat use (ANOVA, p = 0.003), particularly between ground and understorey sites. Akodon montensis selected positively terrestrial ferns and trunks, S. angouya selected lianas, D. albiventris selected fallen trunks and Piper sp., and G. microtarsus choose tree trunks and lianas. We demonstrated that the local small-mammal assemblage does select microhabitats, with different types of associations between species and habitats. Besides, there is a strong evidence of habitat selection in order to diminish predation.
Abstract. Each animal species selects specific microhabitats for protection, foraging, or micro-climate. To understand the distribution patterns of small mammals on the ground and in the understorey, we investigated the use of microhabitats by small mammals in a deciduous forest of southern Brazil. Ten trap stations with seven capture points were used to sample the following microhabitats: liana, fallen log, ground litter, terrestrial ferns, simple-trunk tree, forked tree, and Piper sp. shrubs. Seven field phases were conducted, each for eight consecutive days, from September 2006 through January 2008. Four species of rodents (Akodon montensis, Sooretamys angouya, Oligoryzomys nigripes and Mus musculus) and two species of marsupials (Didelphis albiventris and Gracilinanus microtarsus) were captured. Captured species presented significant differences on their microhabitat use (ANOVA, p = 0.003), particularly between ground and understorey sites. Akodon montensis selected positively terrestrial ferns and trunks, S. angouya selected lianas, D. albiventris selected fallen trunks and Piper sp., and G. microtarsus choose tree trunks and lianas. We demonstrated that the local small-mammal assemblage does select microhabitats, with different types of associations between species and habitats. Besides, there is a strong evidence of habitat selection in order to diminish predation.
sábado, 11 de maio de 2013
Factors affecting the use of space by two rodent species in Brazilian Atlantic forest
BERGALLO, H.G.; MAGNUSSON, W.E. 2004. Factors affecting the use of space by two rodent species in Brazilian Atlantic forest. Mammalia 68(2-3):121-132.
Abstract. The main purpose of this study was to determine whether the maximum distance traveled and home range are of Nectomys squamipes and Oryzomys russatus differ between sexes, breeding seasons and species. We also evaluated whether rainfall and food availability influenced the maximum distance traveled. Rats were trapped monthly from February 1993 to January 1995 in an area of Atlantic forest, Brazil. Maximum distance traveled by N. squamipes was not related to mass and was longer during the breeding season for males. There were not differences between seasons in the distances traveled by O. russatus, but larger males traveled further. Food availability and rainfall had no effect on the distance traveled by each species. Home ranges of male N. squamipes were larger than those of females during the breeding season, but home ranges did not differ between the sexes in O. russatus. Differences between the two species in movement may be related to differences in mating systems, which are probably promiscuous in N. squamipes and monogamous in O. russatus.
Abstract. The main purpose of this study was to determine whether the maximum distance traveled and home range are of Nectomys squamipes and Oryzomys russatus differ between sexes, breeding seasons and species. We also evaluated whether rainfall and food availability influenced the maximum distance traveled. Rats were trapped monthly from February 1993 to January 1995 in an area of Atlantic forest, Brazil. Maximum distance traveled by N. squamipes was not related to mass and was longer during the breeding season for males. There were not differences between seasons in the distances traveled by O. russatus, but larger males traveled further. Food availability and rainfall had no effect on the distance traveled by each species. Home ranges of male N. squamipes were larger than those of females during the breeding season, but home ranges did not differ between the sexes in O. russatus. Differences between the two species in movement may be related to differences in mating systems, which are probably promiscuous in N. squamipes and monogamous in O. russatus.
sábado, 22 de dezembro de 2012
Fruit occurrence in the diet of the Neotropical otter, Lontra longicaudis, in southern Brazilian Atlantic Forest and its implication for seed dispersion
QUADROS, J.; MONTEIRO-FILHO, E.L.A. 2000. Fruit occurrence in the diet of the Neotropical otter, Lontra longicaudis, in southern Brazilian Atlantic Forest and its implication for seed dispersion. Mastozoología Neotropical 7(1):33-36.
Astract. The Neotropical otter has been described as insectivorous and piscivorous cancrivorous. We registered the presence of fruit remains in the scats of the Neotropical otter and developed an analysis about the occurrence and importance of fruits in its diet. This study was carried out from September 1995 to March 1997 in Reserva Volta Velha, an Atlantic Forest area in south Brazil. Otter scats were collected along rivers, washed, dried and analyzed. Seeds found in scats were identified by comparison with a reference collection and their viability was tested in germination ground plots. Fruit collectors helped studying the availability of these fruit species during seven months. A total of 202 scats were collected but only six (3%) presented fruit remains. Identified seeds from only four scats indicated that otters ate three fruit species: Marlierea tomentosa (Myrtaceae), Manilkara subsericea (Sapotaceae) and Pouteria lasiocarpa (Rubiaceae). The availability results indicate that all three are abundant fruit species in the study area, specially the former. In the germination experiments all seeds of M. tomentosa germinated (n=16). Considering the daily movement pattern of the Neotropical otter, and the high germination rate of M. tomentosa, it is possible that the Neotropical otter is a seed disperser for this plant species in the study site.
Astract. The Neotropical otter has been described as insectivorous and piscivorous cancrivorous. We registered the presence of fruit remains in the scats of the Neotropical otter and developed an analysis about the occurrence and importance of fruits in its diet. This study was carried out from September 1995 to March 1997 in Reserva Volta Velha, an Atlantic Forest area in south Brazil. Otter scats were collected along rivers, washed, dried and analyzed. Seeds found in scats were identified by comparison with a reference collection and their viability was tested in germination ground plots. Fruit collectors helped studying the availability of these fruit species during seven months. A total of 202 scats were collected but only six (3%) presented fruit remains. Identified seeds from only four scats indicated that otters ate three fruit species: Marlierea tomentosa (Myrtaceae), Manilkara subsericea (Sapotaceae) and Pouteria lasiocarpa (Rubiaceae). The availability results indicate that all three are abundant fruit species in the study area, specially the former. In the germination experiments all seeds of M. tomentosa germinated (n=16). Considering the daily movement pattern of the Neotropical otter, and the high germination rate of M. tomentosa, it is possible that the Neotropical otter is a seed disperser for this plant species in the study site.
sábado, 17 de novembro de 2012
Jumping ability in the arboreal locomotion of didelphid marsupials
DELCIELLOS, A.C.; VIEIRA, M.V. 2009. Jumping ability in the arboreal locomotion of didelphid marsupials. Mastozoología Neotropical 16(2):299-307.
Abstract. Didelphid marsupials are considered to cross discontinuities between arboreal supports using a cautious locomotion, using the prehensile tail as fifth limb. However, this ability was only described for Caluromys philander. We describe and compare the locomotory performance and postural behavior of seven species of didelphid marsupials crossing discontinuities between artificial supports representing arboreal gaps. Individuals were captured in areas of Atlantic Forest in Rio de Janeiro State, Brazil. Animals were stimulated to jump from a fixed horizontal support one meter above the ground to an inclined support of same diameter. We measured the maximum distance of jump (40, 60, 80 or 100 cm) and reach or distance actually reached by the jump. Arboreal species (Marmosops incanus, Gracilinanus microtarsus, Micoureus paraguayanus, and C. philander) jumped longer distances and had longer relative reach in jumps than semi-terrestrial species (Didelphis aurita, and Philander frenatus). Only the specialized terrestrial Metachirus nudicaudatus did not jump in the tests. The relation between absolute reach and body size was weak and non significant. This study did not corroborate the view that didelphid marsupials cross discontinuities between arboreal supports only through a cautious locomotion, without jumping. On the contrary, we identified patterns of jumping performance and behavior of didelphid marsupials related to their use of the vertical strata.
terça-feira, 11 de setembro de 2012
Daily activity patterns of the Atlantic bamboo rat (Kannabateomys amblyonyx) in southern Brazil.
SARTI, P.T; SILVA, R.B.; VIEIRA, E.M. 2012. Daily activity patterns of the Atlantic bamboo rat (Kannabateomys amblyonyx) in southern Brazil. Neotropical Biology and Conservation 7(2):108-113.
Abstract. Several biotic and abiotic factors influence on daily cycles and mammalian life-history patterns. In this paper, we investigated behavioral patterns and diurnal and nocturnal activity of the Atlantic bamboo rat Kannabateomys amblyonyx (Rodentia, Echimyidae) an endemic species of the Brazilian Atlantic Forest. We conducted the study in the southern portion of the species distribution, in patches of an introduced bamboo species (Bambusa tuldoides) that occurred inside native forest areas. We evaluated behavior and activity time of the individuals by conducting scans during nocturnal and diurnal periods (mean scan length – 24 min, range from 2 to 30 min). We considered the following behavioral categories: feeding, moving, self-cleaning and resting. We did not find significant difference between the diurnal and nocturnal activity (randomized MANOVA, SS = 0.07, d.f. = 45, P = 0.59). The Atlantic Bamboo Rat seemed to be active during the entire 24-h daily period, but with activity peaks by the beginning of the night (between 19:00 and 21:00). The low energy quality provided by food (buds, twigs and bamboo leaves) should compel the rodent to eat several times a day in order to supply their metabolic needs. Besides that, predator activity both during day and night, as well as other local environmental characteristics, probably represents relevant factors that influence the 24-h activity patterns of the studied rodent.
Abstract. Several biotic and abiotic factors influence on daily cycles and mammalian life-history patterns. In this paper, we investigated behavioral patterns and diurnal and nocturnal activity of the Atlantic bamboo rat Kannabateomys amblyonyx (Rodentia, Echimyidae) an endemic species of the Brazilian Atlantic Forest. We conducted the study in the southern portion of the species distribution, in patches of an introduced bamboo species (Bambusa tuldoides) that occurred inside native forest areas. We evaluated behavior and activity time of the individuals by conducting scans during nocturnal and diurnal periods (mean scan length – 24 min, range from 2 to 30 min). We considered the following behavioral categories: feeding, moving, self-cleaning and resting. We did not find significant difference between the diurnal and nocturnal activity (randomized MANOVA, SS = 0.07, d.f. = 45, P = 0.59). The Atlantic Bamboo Rat seemed to be active during the entire 24-h daily period, but with activity peaks by the beginning of the night (between 19:00 and 21:00). The low energy quality provided by food (buds, twigs and bamboo leaves) should compel the rodent to eat several times a day in order to supply their metabolic needs. Besides that, predator activity both during day and night, as well as other local environmental characteristics, probably represents relevant factors that influence the 24-h activity patterns of the studied rodent.
sábado, 18 de agosto de 2012
Ecology of a small mammal community in an Atlantic forest area in southeastern Brazil
BERGALLO, H.G. 1994. Ecology of a small mammal community in an Atlantic forest area in southeastern Brazil. Studies on Neotropical Fauna and Environment 29(4):197-217.
Abstract. During a 14 month mark-and-release project in a Atlantic forest area (Jurélia Ecological Station), I studied the population ecology of 8 species of small mammals (3 marsupials and 5 rodents). In a 4,307 trap nights, 182 individuals were captured 650 times. The rodents were caught 73% of the total capture and the marsupials 27%. Oryzomys nitidus was the commonest species in the grid followed by Proechimys iheringi and Metachirus nudicaudatus. The marsupials showed a seasonal pattern of reproduction. As a consequence, the population densities has a peak during the wet months with the antrance of the youngs . The rodents, P. iheringi and O. nitidus bred throughtout the year, althought the former one has a peak in the dry months. Density of O. nitidus was fairly constant, whereas that of P. ihenrigi was higher during the recruitment time. Rodents and marsupials contributed with the same biomass in Juréia small mammal community.
Abstract. During a 14 month mark-and-release project in a Atlantic forest area (Jurélia Ecological Station), I studied the population ecology of 8 species of small mammals (3 marsupials and 5 rodents). In a 4,307 trap nights, 182 individuals were captured 650 times. The rodents were caught 73% of the total capture and the marsupials 27%. Oryzomys nitidus was the commonest species in the grid followed by Proechimys iheringi and Metachirus nudicaudatus. The marsupials showed a seasonal pattern of reproduction. As a consequence, the population densities has a peak during the wet months with the antrance of the youngs . The rodents, P. iheringi and O. nitidus bred throughtout the year, althought the former one has a peak in the dry months. Density of O. nitidus was fairly constant, whereas that of P. ihenrigi was higher during the recruitment time. Rodents and marsupials contributed with the same biomass in Juréia small mammal community.
sábado, 2 de junho de 2012
Variation in size of colony of Molossus molossus and Molossus rufus in Rio de Janeiro state, Southeastern Brazil
ESBÉRARD, C.E.D. 2011. Variation in size of colony of Molossus molossus and Molossus rufus in Rio de Janeiro state, Southeastern Brazil. Neotropical Biology and Conservation 6(2):71-77.
Abstract. In the Neotropical region, knowledge of seasonal variation of bat colonies is low and appears to be fundamental to the choice of methods for estimating the total number of animals and husbandry. It was analyzed the monthly variations in the size of four colonies, two of Molossus molossus and two of Molossus rufus in Rio de Janeiro State, southeastern Brazil. A total of 60 nights of data collection was conducted in these four colonies, totaling 634 hours of work. The number of animals that comprised each colony was high, 293 and 474 in M. molossus and 165 and 363 in M. rufus. There are two types of colonies: reproductive, when it is observed increase in the number of animals during the months of reproductive activity, and not reproductive, when the colony size is larger in the months of inactive reproduction of the specie in this latitude and few bats remain in the refuge from October to February.
Abstract. In the Neotropical region, knowledge of seasonal variation of bat colonies is low and appears to be fundamental to the choice of methods for estimating the total number of animals and husbandry. It was analyzed the monthly variations in the size of four colonies, two of Molossus molossus and two of Molossus rufus in Rio de Janeiro State, southeastern Brazil. A total of 60 nights of data collection was conducted in these four colonies, totaling 634 hours of work. The number of animals that comprised each colony was high, 293 and 474 in M. molossus and 165 and 363 in M. rufus. There are two types of colonies: reproductive, when it is observed increase in the number of animals during the months of reproductive activity, and not reproductive, when the colony size is larger in the months of inactive reproduction of the specie in this latitude and few bats remain in the refuge from October to February.
sábado, 26 de maio de 2012
Morcegos (Chiroptera) capturados em lagoas do Parque Nacional da Restinga de Jurubatiba, Rio de Janeiro, Brasil
LUZ, J.L.; MANGOLIN, R.; ESBÉRARD, C.E.L.; BERGALLO, H.G. 2011. Morcegos (Chiroptera) capturados em lagoas do Parque Nacional da Restinga de Jurubatiba, Rio de Janeiro, Brasil. Biota Neotropica 11(4):000-000.
Abstract. The aim of this study was to perform a list of bat species captured in six lagoons in the Parque Nacional da Restinga de Jurubatiba, Rio de Janeiro State, Brazil. The park is located about 180 km eastward of Rio de Janeiro city and covers the municipalities of Macaé, Carapebus and Quissamã. The region is dominated by sand dunes and sand ridges formed in the Quaternary. We captured 149 bats belonging to three families and 14 species. Most species caught in restinga de Jurubatiba were frugivores, partly due to technique employed, mist-net, that favors the capture of individuals of the Phyllostomidae family. Five species are uncommonly captured in bats inventories (Uroderma magnirostrum, Lasiurus cinereus, Lophostoma brasiliense, Chiroderma villosum and Diaemus youngi). Species caught varied among lagoons, showing the importance of these habitats for maintaining the diversity of bats.
Abstract. The aim of this study was to perform a list of bat species captured in six lagoons in the Parque Nacional da Restinga de Jurubatiba, Rio de Janeiro State, Brazil. The park is located about 180 km eastward of Rio de Janeiro city and covers the municipalities of Macaé, Carapebus and Quissamã. The region is dominated by sand dunes and sand ridges formed in the Quaternary. We captured 149 bats belonging to three families and 14 species. Most species caught in restinga de Jurubatiba were frugivores, partly due to technique employed, mist-net, that favors the capture of individuals of the Phyllostomidae family. Five species are uncommonly captured in bats inventories (Uroderma magnirostrum, Lasiurus cinereus, Lophostoma brasiliense, Chiroderma villosum and Diaemus youngi). Species caught varied among lagoons, showing the importance of these habitats for maintaining the diversity of bats.
sábado, 7 de abril de 2012
Movement distances of five rodents and two marsupial species in forest fragments of the coastal Atlantic Rainforest, Brazil
PÜTTKER, T.; MEYER-LUCHT, Y.; SOMMER, S. 2006. Movement distances of five rodents and two marsupial species in forest fragments of the coastal Atlantic Rainforest, Brazil. Ecotropica 12:131-139.
Abstract. Movement distances provide information on diverse population biological parameters and are essential in understanding the ecology of a species. Mean distances moved between successive captures (SD), distribution of movement distances, and the mean maximum distances moved (MMDM) were investigated in five rodent and two marsupial species in forest fragments of the coastal Atlantic rainforest (Mata Atlântica) in the state of São Paulo, Brazil. The investigated species were the rodents Akodon montensis (Thomas, 1902), Oligoryzomys nigripes (Olfers, 1818), Delomys sublineatus (Thomas, 1903), Oryzomys russatus (Wagner, 1848), and Thaptomys nigrita (Lichtenstein, 1829), and the marsupials Marmosops incanus (Lund 1840), and Gracilinanus microtarsus (Wagner, 1842). Akodon montensis differed significantly from all other species and moved the lowest SD and MMDM. The marsupials differed significantly from most of the rodents and moved the largest SDs. All species showed the highest frequency of movements in a distance class of 0–20 m. Differences between sexes in SD was detected for O. nigripes, O. russatus, and G. microtarsus, males moving significantly longer distances than females. The different study sites had no influence on SD in any of the investigated species. Only the males of G. microtarsus showed a seasonal variation in SD, moving longer distances during reproductive activity.
Abstract. Movement distances provide information on diverse population biological parameters and are essential in understanding the ecology of a species. Mean distances moved between successive captures (SD), distribution of movement distances, and the mean maximum distances moved (MMDM) were investigated in five rodent and two marsupial species in forest fragments of the coastal Atlantic rainforest (Mata Atlântica) in the state of São Paulo, Brazil. The investigated species were the rodents Akodon montensis (Thomas, 1902), Oligoryzomys nigripes (Olfers, 1818), Delomys sublineatus (Thomas, 1903), Oryzomys russatus (Wagner, 1848), and Thaptomys nigrita (Lichtenstein, 1829), and the marsupials Marmosops incanus (Lund 1840), and Gracilinanus microtarsus (Wagner, 1842). Akodon montensis differed significantly from all other species and moved the lowest SD and MMDM. The marsupials differed significantly from most of the rodents and moved the largest SDs. All species showed the highest frequency of movements in a distance class of 0–20 m. Differences between sexes in SD was detected for O. nigripes, O. russatus, and G. microtarsus, males moving significantly longer distances than females. The different study sites had no influence on SD in any of the investigated species. Only the males of G. microtarsus showed a seasonal variation in SD, moving longer distances during reproductive activity.
sábado, 17 de março de 2012
Ecology of the water opossum Chironectes minimus in Atlantic forest streams of southeastern Brazil
GALLIEZ, M.; LEITE, M.S.; QUEIROZ, T.L.; FERNANDEZ, F.A.S. 2009. Ecology of the water opossum Chironectes minimus in Atlantic forest streams of southeastern Brazil. Journal of Mammalogy 90(1):93-103.
Abstract. We studied the population structure, spatial patterns, and activity patterns of the water opossum (Chironectes minimus) via capture-mark-recapture and radiotelemetry from October 2004 to October 2006 in Atlantic Forest streams in southeastern Brazil. We tested the hypothesis of reproductive seasonality, the usual pattern in neotropical marsupials, by examining recruitment of juveniles. The hypothesis was rejected, supporting the alternative hypothesis that breeding by water opossums was better explained by its habitat characteristics and prey availability than by its phylogenetic ancestry. The observed sex ratio was significantly biased toward males. The home lengths of individual water opossums varied from 844 to 3,724 m. Males had larger home lengths than females, and there were male-male and male-female overlaps. The longer home lengths for males may explain the observed sex ratio bias, because males are more exposed to capture. All individuals used stream stretches with preserved riparian forest, fast-flowing water, and stony substrate. The hypothesis that activity was homogeneously distributed throughout the night was rejected; activity began right after sunset and ended before sunrise, but with higher levels of activity in the first 6 h of the night. Because of anthropogenic alterations of hydrographic basins, water opossums may be threatened by reduction of their main habitat, streams with fast-flowing water and stony substrate.
Abstract. We studied the population structure, spatial patterns, and activity patterns of the water opossum (Chironectes minimus) via capture-mark-recapture and radiotelemetry from October 2004 to October 2006 in Atlantic Forest streams in southeastern Brazil. We tested the hypothesis of reproductive seasonality, the usual pattern in neotropical marsupials, by examining recruitment of juveniles. The hypothesis was rejected, supporting the alternative hypothesis that breeding by water opossums was better explained by its habitat characteristics and prey availability than by its phylogenetic ancestry. The observed sex ratio was significantly biased toward males. The home lengths of individual water opossums varied from 844 to 3,724 m. Males had larger home lengths than females, and there were male-male and male-female overlaps. The longer home lengths for males may explain the observed sex ratio bias, because males are more exposed to capture. All individuals used stream stretches with preserved riparian forest, fast-flowing water, and stony substrate. The hypothesis that activity was homogeneously distributed throughout the night was rejected; activity began right after sunset and ended before sunrise, but with higher levels of activity in the first 6 h of the night. Because of anthropogenic alterations of hydrographic basins, water opossums may be threatened by reduction of their main habitat, streams with fast-flowing water and stony substrate.
sábado, 3 de março de 2012
Uso do espaço vertical por pequenos mamíferos no Parque Nacional Serra dos Órgãos, RJ: um estudo de 10 anos utilizando três métodos de amostragem
PREVEDELLO, J.A.; FERREIRA, P.; PAPI, B.S.; LORETTO, D.; VIEIRA, M.V. 2008. Uso do espaço vertical por pequenos mamíferos no Parque Nacional Serra dos Órgãos, RJ: um estudo de 10 anos utilizando três métodos de amostragem. Espaço & Geografia 11(1):95-119.
Abstract. In this study we analyze the use of forest strata by species of small mammals using three sampling methods: livetraps, artificial nests, and spool-and-line devices. With livetraps and a total effort of 69,525 trap-nights (17,550 in the canopy) there were 2,759 captures of 1,172 individuals of 15 species, eight marsupials and seven rodents. In the nests, the effort was 6,018 nest verifications, with 71 individuals of six species registered. With the spool-and-line devices, 53,000 m of line were tracked in 403 paths of 272 individuals of four species of marsupials. Sampling the canopy was essential to properly characterize the structure of the community, particularly regarding relative abundance of species. The results of the different sampling methods were complementary, each one with its own advantages and limitations to study the vertical use of the forest by small mammals. The combination of the three methods revealed that the small mammal community in Garrafão is clearly stratified, but the vertical use of the forest by small mammals is more complex and sophisticated than a simple classification by dominant strata used. Some species use predominantly the ground, others the canopy, but only these extremes are detected by livetraps. This method alone does not allow a detailed analysis of use of the understory and even the canopy by predominantly terrestrial or scansorial species.
Abstract. In this study we analyze the use of forest strata by species of small mammals using three sampling methods: livetraps, artificial nests, and spool-and-line devices. With livetraps and a total effort of 69,525 trap-nights (17,550 in the canopy) there were 2,759 captures of 1,172 individuals of 15 species, eight marsupials and seven rodents. In the nests, the effort was 6,018 nest verifications, with 71 individuals of six species registered. With the spool-and-line devices, 53,000 m of line were tracked in 403 paths of 272 individuals of four species of marsupials. Sampling the canopy was essential to properly characterize the structure of the community, particularly regarding relative abundance of species. The results of the different sampling methods were complementary, each one with its own advantages and limitations to study the vertical use of the forest by small mammals. The combination of the three methods revealed that the small mammal community in Garrafão is clearly stratified, but the vertical use of the forest by small mammals is more complex and sophisticated than a simple classification by dominant strata used. Some species use predominantly the ground, others the canopy, but only these extremes are detected by livetraps. This method alone does not allow a detailed analysis of use of the understory and even the canopy by predominantly terrestrial or scansorial species.
sábado, 31 de dezembro de 2011
Water absorption of the fur and swimming behaviour of semiaquatic and terrestrial oryzomine rodents
SANTORI, R.T.; VIEIRA, M.V.; ROCHA-BARBOSA, O.; MAGNAN-NETO, J.A.; GOBBI, N. 2008. Water absorption of the fur and swimming behaviour of semiaquatic and terrestrial oryzomine rodents. Journal of Mammalogy 89(5):1152-1161.
Abstract. Locomotion in land and water requires different adaptations, hence semiaquatic mammals must deal with conflicting demands of the 2 environments. Semiaquatic rodents of the tribe Oryzomyini are considered semiaquatic mostly based on habitat use and morphology, but locomotory specializations were not yet determined for most species of the group. We compared water absorption of the fur and swimming behavior between 2 species of oryzomyine water rats (Nectomys) and 2 terrestrial species of Cerradomys. We used adult rodents captured in the wild but acclimated to laboratory conditions. Water absorption rate was determined by the relative increase in body mass after a 5-min swimming session. Animals were videotaped swimming in an aquarium to determine gaits, body posture, maneuverability, and speed. Water absorption rate was significantly lower in semiaquatic species, with no significant difference between sexes. Bipedal paddling was the more frequently used gait by all 4 species, but semiaquatic species were faster and maintained a more hydrodynamic body posture, with a short gliding phase during the gait cycle. Only semiaquatic species were capable of floating effortlessly, and used the swimming bound, a gait similar to the half bound of terrestrial locomotion. Submerged swimming was the fastest swimming gait, used by 1 terrestrial and 1 semiaquatic species. The better performance during bipedal swimming of semiaquatic water rats was related to the improved buoyancy provided by reduced water absorption of the fur, which seemed to represent an important adaptation to move in the water without compromising locomotion on land.
Abstract. Locomotion in land and water requires different adaptations, hence semiaquatic mammals must deal with conflicting demands of the 2 environments. Semiaquatic rodents of the tribe Oryzomyini are considered semiaquatic mostly based on habitat use and morphology, but locomotory specializations were not yet determined for most species of the group. We compared water absorption of the fur and swimming behavior between 2 species of oryzomyine water rats (Nectomys) and 2 terrestrial species of Cerradomys. We used adult rodents captured in the wild but acclimated to laboratory conditions. Water absorption rate was determined by the relative increase in body mass after a 5-min swimming session. Animals were videotaped swimming in an aquarium to determine gaits, body posture, maneuverability, and speed. Water absorption rate was significantly lower in semiaquatic species, with no significant difference between sexes. Bipedal paddling was the more frequently used gait by all 4 species, but semiaquatic species were faster and maintained a more hydrodynamic body posture, with a short gliding phase during the gait cycle. Only semiaquatic species were capable of floating effortlessly, and used the swimming bound, a gait similar to the half bound of terrestrial locomotion. Submerged swimming was the fastest swimming gait, used by 1 terrestrial and 1 semiaquatic species. The better performance during bipedal swimming of semiaquatic water rats was related to the improved buoyancy provided by reduced water absorption of the fur, which seemed to represent an important adaptation to move in the water without compromising locomotion on land.
sábado, 24 de dezembro de 2011
Arboreal walking performance in seven didelphid marsupials as an aspect of their fundamental niche
DELCIELLOS, A.C.; VIEIRA, M.V. 2006. Arboreal walking performance in seven didelphid marsupials as an aspect of their fundamental niche. Austral Ecology 31:449-457.
Abstract. Species of didelphid marsupials (Didelphimorphia, Didelphidae) differ in their use of the forest strata, but it is not clear whether these differences are in fundamental or realized niches. The fundamental niche of seven species of didelphids (Caluromys philander, Didelphis aurita, Gracilinanus microtarsus, Marmosops incanus, Metachirus nudicaudatus, Micoureus demerarae, and Philander frenatus) was compared using their performance in arboreal walking. The association between performance and vertical use of the forest also was tested accounting for phylogenetic and allometric effects. Tests consisted of making the animal cross five 3 m long horizontal supports of different diameters, 1 m from the ground. The cycle of maximum speed was chosen to measure stride length, frequency and velocity. Arboreal species performed better than the terrestrial ones, but a major part of the variation in stride length (70.95%) and stride frequency (88.10%) was associated with body size. Part of the variation in stride length independent of body size (14.05%) was associated with the degree of vertical use of the forest, after phylogenetic effects were accounted for. Fundamental niches of six of the seven species were discriminated with the performance tests used. Discrepancies between the realized and fundamental niches can be inferred for two of these species, D. aurita and P. frenatus.
Abstract. Species of didelphid marsupials (Didelphimorphia, Didelphidae) differ in their use of the forest strata, but it is not clear whether these differences are in fundamental or realized niches. The fundamental niche of seven species of didelphids (Caluromys philander, Didelphis aurita, Gracilinanus microtarsus, Marmosops incanus, Metachirus nudicaudatus, Micoureus demerarae, and Philander frenatus) was compared using their performance in arboreal walking. The association between performance and vertical use of the forest also was tested accounting for phylogenetic and allometric effects. Tests consisted of making the animal cross five 3 m long horizontal supports of different diameters, 1 m from the ground. The cycle of maximum speed was chosen to measure stride length, frequency and velocity. Arboreal species performed better than the terrestrial ones, but a major part of the variation in stride length (70.95%) and stride frequency (88.10%) was associated with body size. Part of the variation in stride length independent of body size (14.05%) was associated with the degree of vertical use of the forest, after phylogenetic effects were accounted for. Fundamental niches of six of the seven species were discriminated with the performance tests used. Discrepancies between the realized and fundamental niches can be inferred for two of these species, D. aurita and P. frenatus.
sábado, 10 de dezembro de 2011
The question of scale in threat analysis: a case study with Brazilian mammals
GRELLE, C.E.V.; FONSECA, G.A.B.; FONSECA, M.T.; COSTA, L.P. 1999. The question of scale in threat analysis: a case study with Brazilian mammals. Animal Conservation 2:149-152.
Abstract. Rates of biodiversity loss are clearly associated with a reduction in the extent of original habitat. The most frequently used method to derive such estimates comes from the well-known species–area relationship. We explored the relationship between habitat loss and area for the Brazilian mammal fauna on a biome level (Atlantic Forest, Cerrado and the Brazilian portion of the Amazon basin), as well as on a smaller regional scale (the Rio Doce Valley of the Atlantic Forest). Habitat loss overestimates the number of threatened species when the entire species pool is considered (endemics and wideranging species). Restricting the analyses to the endemic species, the predicted extinction as a function of habitat loss in the Atlantic Forest and in the Cerrado is found to be greater than the number of taxa actually listed as threatened. This relation is reversed in the Amazon. When considering only the localized species pool for the Rio Doce Valley region of the Atlantic Forest, the function accurately predicts the number of extinctions resulting from habitat loss. We suggest that there is both theoretical and empirical evidence to suggest that threat analysis will generate more accurate estimates of species loss when conducted on a more local scale, particularly for the fauna of non-insular, continental regions. Furthermore, other phenomena affecting the likelihood of extinction of certain groups of species, such as hunting, need to be taken into account in order to better understand the dynamics of biodiversity loss.
Abstract. Rates of biodiversity loss are clearly associated with a reduction in the extent of original habitat. The most frequently used method to derive such estimates comes from the well-known species–area relationship. We explored the relationship between habitat loss and area for the Brazilian mammal fauna on a biome level (Atlantic Forest, Cerrado and the Brazilian portion of the Amazon basin), as well as on a smaller regional scale (the Rio Doce Valley of the Atlantic Forest). Habitat loss overestimates the number of threatened species when the entire species pool is considered (endemics and wideranging species). Restricting the analyses to the endemic species, the predicted extinction as a function of habitat loss in the Atlantic Forest and in the Cerrado is found to be greater than the number of taxa actually listed as threatened. This relation is reversed in the Amazon. When considering only the localized species pool for the Rio Doce Valley region of the Atlantic Forest, the function accurately predicts the number of extinctions resulting from habitat loss. We suggest that there is both theoretical and empirical evidence to suggest that threat analysis will generate more accurate estimates of species loss when conducted on a more local scale, particularly for the fauna of non-insular, continental regions. Furthermore, other phenomena affecting the likelihood of extinction of certain groups of species, such as hunting, need to be taken into account in order to better understand the dynamics of biodiversity loss.
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