Activity patterns, diurnal and nocturnal behaviour of the marsh deer (Blastocerus dichotomus) in the Jataí Ecological Station, Brazil
The marsh deer (Blastocerus dichotomus) is the largest cervid in South America. It is morphologically adapted to the marshes and floodplains that constitute its habitat. The global distribution of the marsh deer has been reduced with 65 % in the last four decades, due to habitat destruction and frag...
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| Formato: | Otro |
| Lenguaje: | sueco Inglés |
| Publicado: |
2009
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| Materias: | |
| Acceso en línea: | https://stud.epsilon.slu.se/10801/ |
| Sumario: | The marsh deer (Blastocerus dichotomus) is the largest cervid in South America. It is morphologically adapted to the marshes and floodplains that constitute its habitat. The global distribution of the marsh deer has been reduced with 65 % in the last four decades, due to habitat destruction and fragmentation, caused by agriculture, cattle grazing and the construction of large hydroelectric dams. It is now threatened with extinction in Brazil. In 1998, five marsh deer were reintroduced in the Jataí Ecological Station, São Paulo State, Brazil, and the population had in 2006 increased to about 20 animals. In this study, we tagged three female marsh deer from the Jataí population with GPS-collars, and from two of them we successfully received data. The marsh deer's activity was recorded in intervals of 5 to 10 minutes, 24 hours a day and for several months, which has never been done before in this species. Activity was measured in two ways; as neck movements and as distance moved in between two recorded time intervals. My results showed that the marsh deer were primarily nocturnal, but with some diurnal activity, especially in the afternoon, whilst activity at dusk and dawn was low. The deer seemed to have moved more in January-February than in November-December, whereas the amount of neck movements did not change over time. No difference between areas used at day and night was detected for the focal animals. The reason for the marsh deer's activity pattern is suggested to be partly due to predator pressure, but the main explanation seems to be environmental conditions, notably temperature. To draw reliable conclusions on the activity patterns of the Jataí-population throughout all seasons, further studies with larger sample sizes and a study period over at least one year would be needed. |
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