Keyword: home range

Activity and group-living in the Porter’s rock rats Aconaemys porteri

, ,

We provide the first systematic data on behavior and ecology of Aconaemys porteri. We used telemetry to monitor patterns of activity, resting locations, and range areas. Rock rat movements were statistically similar during nighttime and daytime, implying no clear diurnal or nocturnal activity. Animals used from 2 to 9 putative resting locations, but one was used more frequently. Rock rats showed relatively smaller range areas and low-to-moderate spatial overlap with neighbors, compared to other rodent species. These results indicate that A. porteri exhibits an intermediate level of sociality, compared to other octodontids.

Patrón de actividad y comportamiento social de Aconaemys porteri. Proporcionamos los primeros datos obtenidos de manera sistematizada sobre el comportamiento y la ecología de Aconaemys porteri. Utilizamos telemetría para monitorear los patrones de actividad, sitios de descanso o refugios, y ámbitos de hogar. Los movimientos de A. porteri tanto para las horas de oscuridad como de luz fueron estadísticamente similares, sugiriendo un patrón de actividad no estrictamente diurno o nocturno. Los animales utilizaron desde 2 hasta 9 sitios de descanso siendo uno de ellos utilizado con mayor frecuencia. Aconaemys porteri exhibió ámbitos de hogar relativamente pequeños y escaso a moderado solapamiento espacial entre individuos. Estos resultados sugieren que A. porteri presenta un nivel de sociabilidad intermedio, en comparación con otros octodóntidos.

Activity pattern and habitat selection by invasive wild boars (Sus scrofa) in Brazilian agroecosystems

, , , ,

Wild boar populations are rapidly spreading through midwest Brazil, causing crop damage, impacting biodiversity and, possibly, spreading diseases to livestock. Despite their threat, little is known about introduced populations in Brazilian agricultural landscapes. The critical lack of knowledge about basic aspects of wild boar spatial ecology led us to evaluate home range sizes, activity pattern and habitat selection in interface regions of agricultural crops and natural riparian forests. We captured and monitored seven individuals using global position system collars throughout 19 to 77 days. The home range sizes calculated by Minimum Convex Polygon and Biased Random Bridge Kernel ranged from 273 to 1253 ha (median = 497 ha) and from 129 to 779 ha (median = 235 ha), respectively. Animals were more active at night, with an activity peak during the first half of the night (between 19:00–03:00 h) and less activity during the hottest hours of day (12:00 h). Wild boars positively selected riverine forests both during the day and night. They also avoided open areas (like crops and pastures), mainly during daylight. Our study provides information to improve control plans, directing capture efforts towards periods of high activity in the preferred habitats used by wild boars in the studied region.

Padrão de atividade e seleção de habitat por javalis invasivos (Sus scrofa) em agroecossistemas brasileiros. As populações de javali estão se espalhando rapidamente pelo centro-oeste do Brasil, causando dano às lavouras, impactando a biodiversidade e, possivelmente, carreando doenças para os animais de criação. Apesar do seu perigo, pouco se conhece sobre as populações introduzidas em áreas agrícolas do país. A crítica falta de conhecimentos sobre aspectos básicos da ecologia espacial dos javalis na região nos levou a capturar e monitorar sete javalis com colares equipados com sistema de posicionamento global de modo a avaliar seus padrões de atividade, características das áreas de vida e padrões de seleção de habitat em áreas de interface entre zonas agrícolas e matas ciliares. Capturamos e rastreamos os animais usando coleiras GPS entre 19 e 77 dias. As áreas de vida estimadas através dos métodos Mínimo Polígono Convexo e Kernel de Pontes Aleatórias Tendenciosas variaram de 273–1253 ha (mediana = 497 ha) e 129–779 ha (mediana = 235 ha) respectivamente. Os animais monitorados foram mais ativos no período noturno, com pico de atividade durante a primeira metade da noite (entre 19:00–03:00 h) e menor atividade nas horas mais quente do dia (12:00 h). Os javalis tiveram clara preferência por áreas de mata ciliar tanto em períodos diurnos quanto noturnos. Eles também evitaram áreas abertas (como lavouras e pastagens), principalmente no período diurno. Nosso estudo fornece informações importantes para aumentar a eficiência dos planos de controle, direcionando esforços de captura para os períodos de maior atividade e para os habitats preferidos pelos javalis na região estudada.

Micromamíferos (Didelphimorphia y Rodentia) del Parque Nacional Lihué Calel, La Pampa, Argentina

, , , ,

Se estudió la comunidad de pequeños mamíferos terrestres (< 500 g) del Parque Nacional Lihué Calel (37° 57′ S, 65° 33′ O, provincia de La Pampa, Argentina) en 1993 y entre los años 2003 y 2006. Se documentaron datos sobre hábitat, ecología, reproducción y estructura de la población en los marsupiales Lestodelphys halli y Thylamys pallidior, los cricétidos Akodon azarae, Akodon molinae, Calomys musculinus, Eligmodontia typus, Graomys griseoflavus, Oligoryzomys longicaudatus y Reithrodon auritus, y los caviomorfos Ctenomys cf. C. azarae, Galea musteloides, Microcavia australis y Tympanoctomys barrerae.

Small mammals (Didelphimorphia and Rodentia) from Parque Nacional Lihué Calel, La Pampa Province, Argentina. We studied the terrestrial small mammal (< 500 g) assemblage from Parque Nacional Lihué Calel (37° 57′ S, 65° 33′ W, La Pampa Province, Argentina) in 1993 and 2003–2006. Information about habitat, ecology, reproduction, and population structure is provided for the didelphid marsupials Lestodelphys halli and Thylamys pallidior, the cricetid rodents Akodon azarae, Akodon molinae, Calomys musculinus, Eligmodontia typus, Graomys griseoflavus, Oligoryzomys longicaudatus, and Reithrodon auritus, and the caviomorph rodents Ctenomys cf. C. azarae, Galea musteloides, Microcavia australis, and Tympanoctomys barrerae.

Movements of Norway rats (Rattus norvegicus) in two poultry farms, Exaltación de la Cruz, Buenos Aires, Argentina

, ,

The aim of this work was to study the range of movements of Norway rats in two poultry farms in Exaltación de la Cruz, Buenos Aires Province. Three female and three male rats were followed by radio-telemetry. The mean home range was 0.024 ha (0.0024 to 0.0525 ha) and the mean maximum distance between localization points was 33.70 m (10 m to 66 m). The maximum daily movement registered was 65 m. Individuals captured near sheds or pigpens did shorter displacements than those captured on the perimeter of each farm. Our results indicate that Norway rats moved only short distances in poultry farms.

Movimientos de ratas noruegas (Rattus norvegicus) en dos granjas avícolas de Exaltación de la Cruz, Buenos Aires, Argentina. El objetivo de este trabajo fue el de estudiar el área mínima de movimientos de la rata noruega en dos granjas avícolas de Exaltación de la Cruz, provincia de Buenos Aires, para lo cual se siguieron los movimientos de seis ratas (tres hembras y tres machos) mediante radio-telemetría. El radio de acción promedio fue de 0.024 ha (0.0024 a 0.0525 ha) y la máxima distancia promedio entre puntos de localización fue de 33.70 m (10 m a 66 m.). El movimiento diario máximo registrado fue de 65 m. Los individuos capturados cerca de los galpones o chiqueros realizaron menores desplazamientos que aquellos capturados en el perímetro de cada granja. Los resultados indican que la rata noruega en las granjas avícolas solo se mueve distancias cortas.

Área de uso e utilização de habitat de cachorro-do-mato (Cerdocyon thous Linnaeus, 1766) no cerrado da região central do Tocantins, Brasil

, ,

Cerdocyon thous é um canídeo com ampla distribuição geográfica pelo Brasil ocupando desde área abertas até ambientes florestados e na região central do Tocantins (Brasil) é um animal relativamente abundante. Entretanto, são poucos os dados na literatura que relatam o uso de habitat e a área de uso deste canídeo no bioma Cerrado. Desse modo,
o objetivo deste estudo foi avaliar o uso de habitat e a área de uso do C. thous no Cerrado na região central do Tocantins. Após a captura e o monitoramento dos animais por rádiotelemetria pode se observar que os animais utilizaram com maior freqüência o Cerrado latu sensu e strictu sensu. As áreas de uso variaram de 2.50 a 6.72 km2 para o MCP (Mínimo Polígono Convexo) e de 5.33 a 7.23 km2 para MH 95% (Média Harmônica 95%). A área centro (área de maior concentração de localizações MH 75%) ocupou 44% da área de uso calculada para a MH 95%. Assim o presente estudo vem contribuir com importantes informações sobre a ecologia deste canídeo em um dos biomas mais ameaçados do mundo.

Home range and habitat use of crab-eating fox (Cerdocyon thous Linnaeus, 1766), in the Cerrado of the central region of Tocantins, Brazil. Cerdocyon thous is a species widely distributed in Brazil, in a variety of habitats ranging from open area to forests and in the central region of Tocantins (Brazil) is relatively abundant. Nevertheless, literature related to habitat use and home range of this canid in the Cerrado biome is scarce. Therefore, the aim of this study was to evaluate the use of habitat and home range of this species in the Cerrado of the central region of Tocantins. After capturing and monitoring three animals by radiotracking, we concluded that all animals spent most of their time in cerrado latu sensu and strictu sensu. Their home range varied from 2.50 to 6.72 for the MCP (Minimum Convex Polygon) and from 5.33 to 7.23 for HM (95% Harmonic Mean). The core area (area with greatest concentration of localization 75% HM) was 44% of the home range calculated for 95% HM. Thus, the present study contributes to the ecology of this canid with valuable information in one of the most threatened biomes in the world.

Áreas de acción en un ensamble de roedores del desierto del Monte (Mendoza, Argentina)

,

Home range of a rodent population in the Monte desert (Mendoza, Argentina). In the central portion of the Monte desert four small rodent species coexist: Graomys griseoflavus, Akodon molinae, Eligmodontia typus, and Calomys musculinus. Using the Convex Polygon Method, we assessed the home range of these species at different habitats and made comparisons among species, and between sexes and different seasons of the year. We found that home range did not differ among species, but there is a tendency to increase range size as the species corporal size increases. Overlapping of home range was different at different seasons of the year, probably due to different population densities, but home range size was constant along the year. Habitat type and sex affect home range only for G. griseoflavus and A. molinae, respectively.

Área de acción, actividad y uso de hábitat del zorro patas negras, Cerdocyon thous, en un bosque seco

,

Se estudió el área de acción de tres zorros patas negras (Cerdocyon thous) en un bosque seco de Santa Cruz, Bolivia a través de radiotelemetría durante un período de 15 meses. Utilizando el Polígono Mínimo Convexo como estimador se encontró que los animales ocuparon áreas entre 280 y 110 ha con un solapamiento mínimo (27 ha) entre vecinos. Los hábitos de los zorros son principalmente nocturnos, con la mayor actividad registrada entre las 17:00 y las 8:00 horas. Prefirieron el bosque ribereño a los bosques chaqueños o de serranía, aunque el primero estaba disponible en un área mucho menor.

Home range, activity, and habitat use of the crab-eating fox (Cerdocyon thous) in a dry forest. The ranging behaviour of three crab-eating foxes in a dry forest in Santa Cruz, Bolivia was studied using radiotracking. Animals occupied an area between 110 and 280 ha estimated with Minimum Convex Polygon and had a small overlap (27 ha) between ranges. The foxes were principally active at night between 17:00 and 8:00 hours. They preferred riparian forest over chacoan and montane forest habitats, although the former was less available than the others.

Home range, social structure, and scent marking behavior in brown brocket deer (Mazama gouazoubira) in a large enclosure

Social organization and scent-marking behavior were studied in a population of brown brocket deer (Mazama gouazoubira) maintained in an enclosure of 14 ha. The deer were usually solitary (74% of sightings), and individuals of both sexes maintained stable home ranges for periods ranging from two to four years. Home ranges of adult males (4 years old) can be considered exclusive (1–2% overlap); there was no overlap of core areas. Females maintained core areas that were 80% exclusive but had overlapping home ranges. For scent-marking (urination, defecation, forehead rubbing and thrashing) frequency a significant difference occurred between males, females and juveniles (p = 0.002; Kruskal-Wallis test) for total marking frequency and instances of urination/defecation. The location of scent marks also varied with age-sex class. Males marked relatively more frequently outside their core areas, while females and juveniles marked more frequently within their core areas. These differences were also statistically significant (p = 0.04; Kruskal-Wallis test). A limited number of aggressive defenses of these home ranges were observed. Home ranges and core areas of males and females respectively are scent marked extensively.

Área de actividad, estructura social y comportamiento de marcado en corzuela parda en semicautiverio. Se estudió la organización social y comportamiento de marcado en una población de corzuelas pardas (Mazama gouazoubira) mantenidas en un cercado de 14 ha. Las corzuelas generalmente fueron solitarias (74% de observaciones) e individuos de ambos sexos mantuvieron áreas de actividad estables por períodos de entre dos y cuatro años. Las áreas de actividad de los machos fueron esencialmente exclusivas (1–2 % de superposición). Las hembras mantuvieron áreas de actividad intensiva las cuales fueron frecuentemente exclusivas (80%) pero tenían superpuestas las áreas de actividad total. La frecuencia de marcado (orinación, defecación, frotado de la frente y movimientos de la cabeza contra la vegetación) fue significativamente diferente entre machos, hembras y juveniles (p = 0.002; prueba de Kruskal-Wallis), tanto para orinación-defecación como para marcas totales. El lugar de marcado también varió con la edad y el sexo. Los machos marcaron relativamente más frecuentemente fuera del lugar de actividad intensiva y las hembras y juveniles marcaron más frecuentemente dentro de sus áreas de actividad intensiva. Estas diferencias fueron significativas estadísticamente (p = 0.04; prueba de Kruskal-Wallis). Se observaron algunas defensas agresivas. Las áreas de actividad y de uso intensivo en machos y hembras fueron respectivamente marcadas extensivamente con marcas olorosas.

Patterns of space use by Micoureus demerarae (Marsupialia: Didelphidae) in a fragment of Atlantic Forest in Brazil

, ,

Space use by the marsupial Micoureus demerarae was studied through mark-recapture trapping in a seven hectare Atlantic Forest fragment, from March 1995 to September 1996. Captures of this species were slightly aggregated within the fragment, and aboveground traps were more successful than the ones placed on the ground. Males had larger home ranges and moved further between successive captures than did females. Two adult males moved between the study area and a nearby forest fragment, crossing 300 m of open vegetation. Home ranges of males overlapped extensively with each other and with those of females. Female home ranges, on the other hand, showed no overlap with each other, with only one exception. These patterns are consistent with the hypothesis that M. demerarae has a promiscuous mating system.

Patrones de uso del espacio de Micoureus demerarae (Marsupialia: Didelphidae) en un fragmento de Selva Atlántica en Brasil. El uso del espacio del marsupial Micoureus demerarae fue estudiado a través de la captura, marcado y recaptura de ejemplares en un fragmento de 7 ha de Selva Atlántica, entre marzo 1995 y setiembre 1996. La captura de ejemplares de esta especie fue levemente agregada dentro del fragmento y las trampas elevadas fueron más efectivas que las colocadas a ras del suelo. Los machos tuvieron un área de actividad mayor que las hembras y se desplazaron mayores distancias que estas entre capturas. Dos machos adultos recorrieron 300 m de vegetación abierta entre el área de estudio y un fragmento de selva cercano. Las áreas de actividad de los machos se superpusieron ampliamente entre sí y con las de las hembras. Por otra parte, las áreas de actividad de las hembras no se superpusieron, con una sola excepción. Estos patrones concuerdan con la hipótesis de que M. demerarae tiene un sistema de apareamiento promiscuo.

Home ranges of Philander frenata and Akodon cursor in a Brazilian restinga (coastal shrubland)

, ,

Home ranges of Philander frenata (= P. opossum) (Didelphimorphia, Didelphidae) and Akodon cursor (Rodentia, Sigmodontinae) in Barra de Maricá, Rio de Janeiro, were estimated and analysed in relation to sex, age, both dry and wet, and breeding and nonbreeding seasons, and correlated with population densities and body weight. In P. frenata, home ranges were predominantly affected by the breeding season, while in A. cursor they were mostly affected by sex. There was no correlation between body weight and home range size within species. No effects of population densities on home range size were found in both species, but we detected an increase in the number of overlapping points of capture with the increase of population densities. Females of A. cursor presented territoriality while males did not. This seems to be a general behaviour in akodontines. Males would have contact with many females, and females would defend nesting and food resources. In P. frenata, neither females nor males seemed to be territorial, presenting a mating system without permanent
couples.