Barn Owl pellets (Aves: Tyto furcata) reveal a higher mammalian richness in the Restinga de Jurubatiba National Park, Southeastern Brazil

LEMOS, H.M.; SILVA, C.A.O.; PATIU, F.M.; GONÇALVES, P.R. 2015. Barn Owl pellets (Aves: Tyto furcata) reveal a higher mammalian richness in the Restinga de Jurubatiba National Park, Southeastern Brazil. Biota Neotropica 15(2):1-9. http://dx.doi.org/10.1590/1676-06032015012114

Abstract. The northern coast of the state of Rio de Janeiro harbors the largest coastal sandy plains (restingas) of southeastern Brazil, severely threatened due to recent human occupation. In this context, mammal inventories becomes urgent to support biodiversity conservation and management policies. This paper aims to update the knowledge on the mammalian species richness of Restinga de Jurubatiba National Park by analyzing pellets of the Barn owl Tyto furcata. The analyses of 4745 mammalian bone fragments (1739 individuals) revealed the occurrence of 17 species belonging to the orders Rodentia (9 spp.), Didelphimorphia (2 spp.) and Chiroptera (6 spp.). The rodents Mus musculus and Cerradomys goytaca accounted for 77.2% of the total individuals preyed, suggesting that the Barn owl hunts in both disturbed and natural open shrub formations. A compilation of previous records, together with those provided in the present study, indicates the occurrence of 44 species of mammals in the Restinga de Jurubatiba National Park, of which six (13.6%) were exclusively detected in pellets. These new records include species adapted to open formations of the interior of Brazil that were not previously reported in restingas on the basis of voucher-specimens, such as the rodents Necromys lasiurus and Calomys tener, the latter being recorded for the first time in the littoral of Rio de Janeiro state. This study underscores the importance of owl pellet analysis as a complementary and indispensable method for inventorying mammals. The results highlight the Restinga de Jurubatiba National Park as one of the restingas in Southeastern Brazil with the highest number of mammal species.

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.

Small mammals in the diet of Barn owls, Tyto alba (Aves: Strigiformes) along the mid-Araguaia River in central Brazil

ROCHA, R.G.; FERREIRA, E.; LEITE, Y.L.R.; FONSECA, C.; COSTA, L.P. 2011. Small mammals in the diet of Barn owls, Tyto alba (Aves: Strigiformes) along the mid-Araguaia River in central Brazil. Zoologia 282(6):709-716. doi: 10.1590/S1984-46702011000600003

Abstract. We collected and analyzed 286 Barn owl, Tyto alba (Scopoli, 1769), pellets from two nests in different environments along the mid-Araguaia River in central Brazil. Our analyses revealed that these owls feed mainly on small mammals, especially rodents. Owls from the riverbanks at Fazenda Santa Fé had a more diverse diet, preying mainly on rodents that typically inhabit riparian grasslands – Holochilus sciureus Wagner, 1842 – and forests – Hylaeamys megacephalus (Fischer, 1814) and Oecomys spp., which probably also occur in forest borders or clearings. On the other hand, owls from an agroecosystem at Fazenda Lago Verde preyed mostly on rodent species common in these agrarian fields, Calomys tocantinsi Bonvicino, Lima & Almeida, 2003. Additionally, we compared small mammal richness estimates based on the analysis of owl pellets with estimates from live-trapping in the same areas. Owl pellets revealed two rodent species undetected by live traps – Euryoryzomys sp. and Rattus rattus (Linnaeus, 1758) – and four rodent species were trapped, but not found in owl pellets – Oecomys roberti Thomas, 1904, Pseudoryzomys simplex (Winge, 1887), Rhipidomys ipukensis Rocha, B.M.A. Costa & L.P. Costa, 2011, and Makalata didelphoides (Desmarest, 1817). Traps yielded higher species richness, but these two methods complement each other for surveying small rodents

Arboreal tropical forest vertebrates: current knowledge and research trends

KAYS, R.; ALLISON, A. 2001. Arboreal tropical forest vertebrates: current knowledge and research trends. Plant Ecology 153:109-120.

Abstract. We review the ecology and specialized methods required for studying arboreal mammals, birds, reptiles and amphibians, and use faunal checklists from 12 tropical wet forest sites and an analysis of all articles published during the past ten years in 14 major journals to assess current knowledge and general research trends for these groups. The percentage of arboreal vertebrates was remarkably similar at the different sites (76.2+/-3.9%). Birds were the most arboreal group and amphibians and reptiles the least. The review of journals showed that primates were overwhelmingly the most studied group (336 papers), followed by bats (105), passeriform birds (73) and rodents (55). Judging by their portion of the arboreal vertebrate community and the number of papers surveyed, birds and amphibians and reptiles are vastly understudied compared to mammals, but this is largely due to the great number of primate studies. The number of publications on arboreal vertebrates has remained relatively stable over the last 10 years for all taxa except primates, which have seen a growth in publications. Canopy vertebrates from Brazil had by the most publications (120), followed by Madagascar (61), Costa Rica (55) and Indonesia (42). We conclude by highlighting the priorities we see for future studies on tropical canopy vertebrates.

Differences in population density and energy use between birds and mammals: a macroecological perspective

SILVA, M.; BROWN, J.H.; DOWNING, J.A. 1997. Differences in population density and energy use between birds and mammals: a macroecological perspective. Journal of Animal Ecology 66(3):327-340.

Abstract.
1. Data from 364 mammal and 564 bird species were used to compare these two taxa in the patterns of variation in population density and energy use as a function of body mass.
2. This study demonstrates previously unappreciated quantitative differences between mammals and birds. Over a wide range of sizes, population densities and rates of energy use are at least one order of magnitude higher in mammals than in birds of similar size. The highest population densities are found in species that weigh about 100 g in mammals and 30 g in birds.
3. Comparisons between mammals and birds from the same dietary category indicate that mammals maintain higher densities and use more energy than birds. Insectivorous mammals and birds maintain the lowest densities.
4. Flying mammals and birds reach lower densities and use more energy than nonflying forms.

5. These findings reveal relationships between the morphology, physiology and behaviour of individual organisms and the ecological performance of these endothermic vertebrates in populations, communities and ecosystems: relationships that have not previously been appreciated.

Impact of hunting on large vertebrates in the Mbaracayu Reserve, Paraguay

HILL, K.; PADWE, J.; BEJYVAGI, C.; BEPURAGI, A.; JUKAGI, F.; TYKUARANGI, R.; TYKUARANGI, T. 1997. "Impact of hunting on large vertebrates in the Mbaracayu Reserve, Paraguay. Conservation Biology 11(6):1339-1353.

Abstract. Over 1,400,000 m of line transect data were collected in collaboration with Ache Indians to determine encounter rates with all large vertebrates in the Mbaracayu Reserve Paraguay. The data were analyzed using logistic regression in order to determine the impact of human hunting on animal encounter rates in the reserve. The method controlled for effects of season, weather, time of day, and habitat in order to statistically isolate the human predation effect. Encounters with the animals themselves as well as fresh signs of their activity allowed us to determine whether lower encounter rates in hunted zones are simply due to increased wariness by target species. Our results show that areas near hunters are hunted more frequently, and that Dasypus novemcinctus, Cebus apella, Tapirus terrestris, and Mazama spp. are all encountered at lower rates in those areas than in unhunted zones. We were unable to show that encounter rates with other important game species have been affected by human hunting. Demonstration of local depletion by central place foragers is expected, However, and cannot be used to conclude that prey species are in danger of regional extirpation.