We describe the reproductive parameters of tufted capuchins (Cebus apella nigritus) in the Iguazú... more We describe the reproductive parameters of tufted capuchins (Cebus apella nigritus) in the Iguazú National Park, NE Argentina. We obtained data on six different groups (33 individually recognized adult females) studied for periods of 2–9 years. Estimated birthrate is 0.59 infants per female per year in unprovisioned groups. A group that was provisioned for 6 years during the winter period of low fruit availability (May–August), showed a similar birth rate of 0.61, but a lower infant mortality rate than unprovisioned groups. The birthrate estimated for this population is higher than the one reported for white-faced and wedge-capped capuchins. The mean interbirth interval is 19.35 months, but a female can have infants in successive years, even when her previous infant has survived. The modal age at first delivery is 7 years, which is similar to the one observed in wedge-capped capuchins. When young adult females come into estrous they avoid copulating with the alpha male that sired them, thus providing evidence for a behavioral mechanism of inbreeding avoidance. Births are very seasonal at Iguazú, occurring during the spring and summer months (October–February) when food availability is at its peak. Tufted capuchins at Iguazú are more seasonal breeders than other capuchin populations, probably as a result of their more seasonal environment. The secondary sex ratio does not deviate significantly from 1:1, despite the known ability of capuchins to adjust secondary sex ratio to local conditions.
Hunting by humans may affect the abundance and activity patterns of game species. We examined the... more Hunting by humans may affect the abundance and activity patterns of game species. We examined the effect of hunting on the abundance and activity patterns of sympatric red brocket deer Mazama americana and dwarf brocket deer M. nana. We conducted four camera-trap surveys (158 sampling stations, 10,244 trap-days, total area sampled 1200 km2) in three areas within the Atlantic Forest of Misiones, Argentina, that differ in protection and hunting pressure. We used logistic regression and tests of independence to evaluate if protection, hunting pressure, and other independent variables affect the probability of recording each species and their recording rate. We used the Mardia–Watson–Wheeler test to examine if the daily activity pattern differs between species and changes with hunting pressure. Red brocket deer were more frequently recorded (397 records, 58% of stations) than dwarf brocket deer (100 records, 37% of stations). The probability of recording red brockets was higher in areas with better protection and increased with the distance to the main accesses used by poachers. The probability of recording dwarf brockets was higher in areas with low protection. Red brockets were more nocturnal than dwarf brockets, a difference that may reduce interspecific competition. However, red brockets were more diurnal in the best-protected areas, suggesting that they can adjust their activity to local hunting pressure. Hunting has opposite effects on the abundance of these deer and may facilitate their coexistence. Hunting should be carefully controlled or managed to ensure the conservation of these little known species.
We describe the reproductive parameters of tufted capuchins (Cebus apella nigritus) in the Iguazú... more We describe the reproductive parameters of tufted capuchins (Cebus apella nigritus) in the Iguazú National Park, NE Argentina. We obtained data on six different groups (33 individually recognized adult females) studied for periods of 2–9 years. Estimated birthrate is 0.59 infants per female per year in unprovisioned groups. A group that was provisioned for 6 years during the winter period of low fruit availability (May–August), showed a similar birth rate of 0.61, but a lower infant mortality rate than unprovisioned groups. The birthrate estimated for this population is higher than the one reported for white-faced and wedge-capped capuchins. The mean interbirth interval is 19.35 months, but a female can have infants in successive years, even when her previous infant has survived. The modal age at first delivery is 7 years, which is similar to the one observed in wedge-capped capuchins. When young adult females come into estrous they avoid copulating with the alpha male that sired them, thus providing evidence for a behavioral mechanism of inbreeding avoidance. Births are very seasonal at Iguazú, occurring during the spring and summer months (October–February) when food availability is at its peak. Tufted capuchins at Iguazú are more seasonal breeders than other capuchin populations, probably as a result of their more seasonal environment. The secondary sex ratio does not deviate significantly from 1:1, despite the known ability of capuchins to adjust secondary sex ratio to local conditions.
Hunting by humans may affect the abundance and activity patterns of game species. We examined the... more Hunting by humans may affect the abundance and activity patterns of game species. We examined the effect of hunting on the abundance and activity patterns of sympatric red brocket deer Mazama americana and dwarf brocket deer M. nana. We conducted four camera-trap surveys (158 sampling stations, 10,244 trap-days, total area sampled 1200 km2) in three areas within the Atlantic Forest of Misiones, Argentina, that differ in protection and hunting pressure. We used logistic regression and tests of independence to evaluate if protection, hunting pressure, and other independent variables affect the probability of recording each species and their recording rate. We used the Mardia–Watson–Wheeler test to examine if the daily activity pattern differs between species and changes with hunting pressure. Red brocket deer were more frequently recorded (397 records, 58% of stations) than dwarf brocket deer (100 records, 37% of stations). The probability of recording red brockets was higher in areas with better protection and increased with the distance to the main accesses used by poachers. The probability of recording dwarf brockets was higher in areas with low protection. Red brockets were more nocturnal than dwarf brockets, a difference that may reduce interspecific competition. However, red brockets were more diurnal in the best-protected areas, suggesting that they can adjust their activity to local hunting pressure. Hunting has opposite effects on the abundance of these deer and may facilitate their coexistence. Hunting should be carefully controlled or managed to ensure the conservation of these little known species.
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