Double effort: Parental behavior of wild Azara's owl monkeys in the face of twins.

In species of mammals that habitually bear single offspring, like most anthropoid primates, the occurrence of twins is expected to impose considerable energetic costs on the caretakers. The question then arises of how caregivers cope with the potentially increased costs of raising twins. These increased costs should lead to differing developmental rates in twins when compared to singletons, and/or to changes in the caregivers' behavior. Likewise, time budgets of parents of singletons are expected to differ from those of adults without offspring. Additionally, if twinning was an adaptive response to favorable ecological conditions, it should be more likely in years with high food abundance. Following the birth in 2011 of two sets of twins in a wild population of pair-living Azara's owl monkeys (Aotus azarae) in Northern Argentina, we used long-term demographic, behavioral, and phenological data to compare (a) the proportion of time that singleton and twin infants were carried by either parent; (b) adult time budgets and ranging behavior in groups with zero, one, or two infants; and (c) the availability of food in 2011 with food availability in other years. Twins, like singletons, were carried nearly exclusively by the male, and they were carried slightly more than singletons, suggesting a relatively inflexible pattern of infant care in the species. Time budgets showed that twin parents foraged more and moved less than singleton parents or groups without infants, despite the fact that phenological data indicate that fruit availability in 2011 was not substantially higher than in some of the other years. Overall, twinning thus presumably increased costs to breeders, especially males, but its effect on animals' long-term reproductive success remains unclear.

[Epidemic dermatits by Paederus irritans in Piura, Perú at 1999, related to El Niño phenomenon]. / Dermatite epidêmica por Paederus irritans em Piura, Perú, 1999, relacionada ao fenômeno El Niño.

The phenomen El Niño that affected Peru at 1998, made possible the growth of copious vegetation in traditionally dry places. On this way, Paederus irritans, dipterous of the order Coleoptera that produces dermatitis when croushed on the skin, found substract that allowed the natural growth of its population. The coming of occasional rains on the months of February to April 1999, attacked the habitat of this insect, that looked for urban areas, exposing seriously the general population of Piura on north Perú to the contact. During February and May 1,451 cases of dermatitis caused by Paederus irritans, called latigazo because of its linear and eritematous characteristic lesions on the skin, were notified at Piura. The more affected body areas were head (56.6%) and neck (30.9%), but there were also cases of conjunctivitis and genital injuries, because of hands contamination.

Dermatite epidêmica por Paederus irritans em Piura, Perú, 1999, relacionada ao fenômeno El Niño / Epidemic dermatits by Paederus irritans in Piura, Peru at 1999, related to El Niño phenomenon

The phenomen El Niño that affected Peru at 1998, made possible the growth of copious vegetation in traditionally dry places. On this way, Paederus irritans, dipterous of the order Coleoptera that produces dermatitis when croushed on the skin, found substract that allowed the natural growth of its population. The coming of occasional rains on the months of February to April 1999, attacked the habitat of this insect, that looked for urban areas, exposing seriously the general population of Piura on north Perú to the contact. During February and May 1,451 cases of dermatitis caused by Paederus irritans, called latigazo because of its linear and eritematous characteristic lesions on the skin, were notified at Piura. The more affected body areas were head (56.6) and neck (30.9), but there were also cases of conjunctivitis and genital injuries, because of hands contamination.