A transitoriedade entre o mundo primitivo e o moderno nas obras The Sea-Wolf e White Fang de Jack London

The American author Jack London wrote the books The Sea-Wolf and White Fang in 1904 and 1906, respectively. The former portrays the life of a literary critic, Humphrey Van Weyden, who after the wreckage of the ship in which he was is rescued by a seal-hunting schooner, where he is obliged to work and to live with the brutal captain Wolf Larsen, and in doing so he develops a more primitive profile. The latter work portrays the life of the eponymous character, a wolf that leaves the wild world in which it was born to follow its last master in the city, thus developing features of the modern world. This paper aims to conduct an analysis of the aspects that allow the transition between the primitive and the modern world in those works

OSLERUS OSLERI (COBBOLD, 1876) INFECTION IN MANED WOLF (CHRYSOCYON BRACHYURUS, ILLIGER, 1815)

Oslerus osleri is a small nematode that infects the respiratory tract of domestic and wild canids and is responsible for causing chronic nodular tracheobronchitis. This paper aims to report a case of parasitism by O. osleri in a free-living maned wolf (Chrysocyon brachyurus) that was struck by a motor vehicle. Fecal samples were collected, and the presence of spiral larvae, with S-shaped tails, was observed on flotation. This characteristic was compatible with the Filaroididae Family larvae of O. osleri. Although the animal did not show clinical signs of respiratory system impairment, a tracheobronchoscopy was performed. Semitransparent nodules, 5 mm in diameter, containing adult parasites were observed in the third distal portion of the trachea, cranial to the carina. Larval morphological characteristics and the nodular locations were compatible with an O. osleri respiratory tract infection.

Unsuccessful attacks dominate a drone-preying wasp's hunting performance near stingless bee nests

Bee males (drones) of stingless bees tend to congregate near entrances of conspecific nests, where they wait for virgin queens that initiate their nuptial flight. We observed that the Neotropical solitary wasp Trachypus boharti (Hymenoptera, Cabronidae) specifically preys on males of the stingless bee Scaptotrigona postica (Hymenoptera, Apidae); these wasps captured up to 50 males per day near the entrance of a single hive. Over 90% of the wasp attacks were unsuccessful; such erroneous attacks often involved conspecific wasps and worker bees. After the capture of non-male prey, wasps almost immediately released these individuals unharmed and continued hunting. A simple behavioral experiment showed that at short distances wasps were not specifically attracted to S. postica males nor were they repelled by workers of the same species. Likely, short-range prey detection near the bees' nest is achieved mainly by vision whereas close-range prey recognition is based principally on chemical and/or mechanical cues. We argue that the dependence on the wasp's visual perception during attack and the crowded and dynamic hunting conditions caused wasps to make many preying attempts that failed. Two wasp-density-related factors, wasp-prey distance and wasp-wasp encounters, may account for the fact that the highest male capture and unsuccessful wasp bee encounter rates occurred at intermediate wasp numbers.

Hunting spiders of woodland fragments and agricultural habitats in the Atlantic rain forest region of Brazil

The hunting spider communities of the Dionycha clade were studied 1986 through 1988 in fragmented woodlands and secondary agricultural habitats of the Botucatu area in São Paulo state, Brazil. The original vegetation of mainly tropical Atlantic rain forest (Mata Atlantica) was cleared already 70 years ago. In a total sample of over 1000 adult spiders, 247 species belonging to 12 families Mere determined. A decreasing frequency and diversity of spiders rc as found if forest remnants were compared with sugar cane fields and cattle pasture. The specific composition of the spider fauna as surveyed in different habitats is discussed under ecological aspects and in relation to the history of land use.

Stirring, charging, and picking: hunting tactics of potamotrygonid rays in the upper Paraná River

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Diet of the maned wolf (Chrysocyon brachyurus) and its role in seed dispersal on a cattle ranch in Brazil

The maned wolf Chrysocyon brachyurus is the largest canid inhabiting South America. Its geographic distribution includes the open fields of Brazil's central area, which is currently undergoing agricultural expansion. The diet of the maned wolf and its seasonal variation was determined on a dairy cattle ranch (Sao Luis farm, 566 ha) in the State of Minas Gerais, Brazil. From January to December faeces of the maned wolf were collected monthly (n = 150 scats; 397 food item occurrences). Twenty-nine taxa were identified from scats, 18 of animal origin (46% or 183 occurrences) and 11 of plants (54% or 214 occurrences). The fruits of Solanum lycocarpum were the dominant food item in our study (29%). Mammals contributed 13%, arthropods 12%, birds 11% and reptiles 2% of the food items. Arthropods and fruits were prevalent in the rainy season and mammals in the dry season. As expected for a heavily fanned region, frugivory results were at the lower end of the diversity scale (9-33 species) and included four old garden species. No previous study of the diet of maned wolf has registered as many species of Solanaceae as this one. Although dietary richness was lower, the main food items (wolf fruit, armadillos, rodents, birds) were the same as study sites in 'cerrado' and upland meadows. In this region, the open habitats occupied by the maned wolf were previously covered by Atlantic forest, suggesting that landscape modification such as cattle ranching has opened new frontiers for distribution expansion of the maned wolf. The impact of loss of dietary richness and the increase in Solanaceae on the survival of the maned wolf need to be evaluated.

Diet of the maned wolf, Chrysocyon brachyurus (Mammalia : Canidae), during wet and dry seasons at Ibitipoca State Park, Brazil

Analysis of 141 seats of maned wolf Chrysocyon brachyurus collected in a region of upland forest and meadows of south-eastern Brazil yielded 351 food items in the wet season (60 seats) and 407 in the dry season (81 seats). Scarabaeidae and rodents were the most frequent animal food in both seasons, complemented by birds in the wet season and unidentified mammals in the dry season. Seeds revealed Solanum lycocarpum to be the most frequent plant food in the dry season and an Annonaceae and a Cactaceae the most frequent in the wet season. A total of 33 seed morphospecies were retrieved. Although our results reveal some shared and some divergent trends from dietary studies undertaken in savanna ('cerrado') areas, we found a very high frequency of potentially harmful tourists' garbage. This highlights the necessity for better environmental education and confirms that the maned wolf is a generalist and opportunist omnivore.

Individual Specialization in the Hunting-wasp Trypoxylon (Trypargilum) agamemnon Richards (Hymenoptera: Crabronidae)

Renan B. Pitilin, Marcio S. Araujo, and Maria L.T. Buschini (2012) Individual specialization in the hunting-wasp Trypoxylon (Trypargilum) agamemnon Richards (Hymenoptera: Crabronidae). Zoological Studies 51(5): 655-662. Individuals of a population may differ with respect to resource use. This among-individual variation in resource utilization is called 'individual specialization' and may substantially impact the ecological and evolutionary dynamics of a population. The aim of this study was to evaluate whether females of 1 population of the hunting-wasp Trypoxylon agamemnon differed in their preferences for spider size and/or taxa. To observe the behavior of wasps, trap-nests were installed in an araucaria forest fragment in the Parque Municipal das Araucarias, Guarapuava (PR), southern Brazil. The indices within-individual component (WIC)/total niche width of a population (TNW) and average of values of the proportional similarity index (IS) were used to measure the degree of individual specialization. We found evidence of strong, significant individual specialization in T agamemnon in terms of both prey size (WIC/TNW = 0.43) and taxa (IS = 0.45). We hypothesized that individual specialization in this species resulted from cognitive tradeoffs that limit individuals to exploring a small subset of available resources. http://zoolstud.sinica.edu.tw/Journals/51.5/655.pdf

Crystal structure of hemoglobin from the maned wolf (Chrysocyon brachyurus) using synchrotron radiation

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

Crystallization, preliminary X-ray diffraction analysis and Patterson search of oxyhaemoglobin I from the wolf (Chrysocyon brachiurus)

Oxyhaemoglobin I isolated from the Brazilian wolf Chrysocyon brachiurus has been crystallized and X-ray diffraction data has been collected to 2.06 A resolution using a synchrotron-radiation source. Crystals were determined to belong to the space group P2(1)2(1)2(1) and preliminary structural analysis revealed the presence of one tetramer in the asymmetric unit. The structure was determined using standard molecular-replacement techniques and is currently being refined using maximum-likelihood protocols. This is the first haemoglobin isolated from a member of the Canidae family to be crystallized and it will provide further insights in the comparative biochemistry of vertebrate haemoglobins.

To be or not to be . . . a flower? A test of possible cues influencing hunting site selection in subadult females of the crab spider Epicadus heterogaster (Guerin 1812) (Araneae: Thomisidae)

Females of some Thomisidae species are known to use visual and olfactory stimuli to select high quality hunting sites. However, because studies about foraging behavior in this family are concentrated on a few species, the comprehension of the process related to hunting behavior evolution in crab spiders may be biased. In this study we investigated the hunting site selection of a previously unstudied crab spider, Epicadus heterogaster. We performed three experiments to evaluate the hypothesis that subadult females are able to use visual and olfactory stimuli to select hunting sites. In the first experiment, females did not preferentially select flower paper models that matched their body coloration. However, after choosing a model that had the same body color as the spider, they remained on it for longer periods than on models with different colors. In the second experiment, females did not discriminate between flower paper models, natural flower models and crumpled paper models. Females did also not discriminate among different olfactory stimuli in the third experiment. It is possible that subadult females of E. heterogaster need to establish and experience a given hunting site before evaluating its quality. However, it remains to be investigated if they use UV cues to select a foraging area before experiencing it.

Guiana dolphins (Sotalia guianensis) displaying beach hunting behavior in the Cananéia Estuary, Brazil: social context and conservation issues

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

Biology and behaviour of the neotropical ant-mimicking spider Aphantochilus rogersi (Araneae: Aphantochilidae): nesting, maternal care and ontogeny of ant-hunting techniques

Aphantochilus rogersi is an ant-mimicking spider that preys exclusively on cephalotine ants. The spiders oviposit in close proximity to nests of the model ant Zacryptocerus pusillus, and emergent spiderlings tend to remain in the vicinity of natal egg sacs. Females of A. rogersi actively defend their egg sacs against approaching workers of Z. pusillus, but the latter may sometimes destroy the eggs. Feeding specialization on these ants is confirmed by more than 300 observations of young and adult A. rogersi carrying ant corpses in the held. Although A. rogersi possesses several behavioural traits which may reduce the risk of being injured by ants during subjugation, field and laboratory observations showed that social defence by Z. pusillus may cause mutilation to the spiders. Tests in captivity revealed an ontogenetic change in the prey-capture techniques employed by A. rogersi. Early-instar spiderlings can apparently only seize the ant's petiole tightly if they are able to approach the ant from the front. As the ant is paralysed, the spiderling positions itself vertically in relation to the substratum. Larger spiders, on the other hand, attack ants most frequently from behind, and seem better equipped to seize the ant's petiole firmly with their larger chelicerae. Owing to their greater strength, late-instar spiders are able to Lift the struggling ant aloft. The selection of a suitable oviposition site, the mother's ability to defend herself and the eggs from nearby ants, and the capacity to capture and subdue ants safely from emergence to maturity, are regarded as crucial traits inherent in the mimetic and feeding specialization by A. rogersi.