Coping Mechanisms used by Socially and Emotionally Isolated Older Adults

This exploratory and descriptive qualitative study was undertaken to examine the nature of social and emotional isolation as it impacts older adults by examining the coping mechanisms they use. The participants (N=15), clients of Senior Community Services and CommonBond Communities, completed a structured interview consisting of nineteen primarily open-ended questions. The study looked at the issues of social and emotional isolation as it was identified by participants, the amount of support they received, and the methods they used to cope with any recognized feelings of isolation. The survey identified those persons involved in the senior\u27s life, how frequently contact was available, and how involvement in activities affected older adults. Theories, including stress and coping, activity, and convoy of social relations were used to explore the relationship between aging and coping with social and emotional isolation. The findings of this study suggest that adults over age 70 do experience feelings of loneliness at times. They have frequent contact with other people and have supportive people in their lives. They find ways to deal with their loneliness, usually choosing solitary activities such as television or reading. The results provide implications for future social work in the delivery of services to older adults

My Home Is Your Castle: Roost Making Is Sexually Selected in the Bat Lophostoma silvicolum

Shelters are important for the survival and reproduction of many animals and this is particularly true for bats. Depending on the future use and effect of shelters on the fitness of individuals, not all members of a group of animals may contribute equally to shelter making. Thus, knowledge about the identity of shelter-making individuals may teach us much about the social system and mating strategy of species. To exemplify this, we review what is known about the roost-making behavior and the social system of Lophostoma silvicolum, a neotropical bat that excavates roost cavities in active arboreal termite nests. Roosts in termite nests are highly beneficial for the bats because they offer improved microclimate and possibly are responsible for the lower parasite loads of L. silvicolum in comparison to bat species using other, more common, roost types. Examination of observational field data in combination with genetic analyses shows that roost cavities excavated by single males subsequently serve as maternity roosts for females and that this improves reproductive success of the male who excavated the roost. This suggests that roosts in termite nests serve as an extended male phenotype and roost making is a sexually selected behavior. Roost-making behavior is tightly linked to the species' social organization (single-male-multifemale associations that stay together year-round) and mating system (resource-defense polygyny). The case study of L. silvicolum shows that it is important to learn more about the implications of shelter making in bats and other animals from ongoing and future studies. However, differences in costs and benefits for each group member must be carefully evaluated before drawing conclusions about social systems and mating strategies in order to contribute to our current knowledge about the evolution of sociality in mammal

All-offspring dispersal in a tropical mammal with resource defense polygyny

In polygynous mammals, males are usually responsible for gene flow while females are predominantly philopatric. However, there is evidence that in a few mammalian species female offspring may disperse to avoid breeding with their father when male tenure exceeds female age at maturity. We investigated offspring dispersal and local population structure in the Neotropical bat Lophostoma silvicolum. The mating system of this species is resource defense polygyny, with the resource being active termite nests, excavated by single males, which are then joined by females. We combined field observations of 14 harems during 3years and data about the genetic structure within and between these groups, calculated with one mitochondrial locus and nine nuclear microsatellite loci. The results show that both male and female offspring disperse before maturity. In addition, we estimated life span of excavated termite nests and the duration they were occupied by the same male. Our findings suggest that long male tenure of up to 30months is indeed a likely cause for the observed dispersal by female offspring that can reach maturity at a low age of 6months. We suggest that dispersal by offspring of both sexes may occur quite frequently in polygynous tropical bats and thus generally may be more common in mammals than previously assume

Mating system of a Neotropical roost-making bat: the white-throated, round-eared bat, Lophostoma silvicolum (Chiroptera: Phyllostomidae)

The vast majority of bats strongly depend on, but do not make, shelters or roosts. We investigated Lophostoma silvicolum, which roosts in active termite nests excavated by the bats themselves, to study the relationship between roost choice and mating systems. Due to the hardness of the termite nests, roost-making is probably costly in terms of time and energy for these bats. Video-observations and capture data showed that single males excavate nests. Only males in good physical condition attracted females to the resulting roosts. Almost all groups captured from excavated nests were single male-multifemale associations, suggesting a harem structure. Paternity assignments based on ten polymorphic microsatellites, revealed a high reproductive success of 46% by nest-holding males. We suggest that the mating system of L. silvicolum is based on a resource-defense polygyny. The temperatures in the excavated nests are warm and stable, and might provide a suitable shelter for reproductive females. Reproductive success achieved by harem males appears to justify the time and effort required to excavate the nests. Reproductive success may thus have selected on an external male phenotype, the excavated nests, and have contributed to the evolution of an otherwise rare behavior in bat

Absent or Low Rate of Adult Neurogenesis in the Hippocampus of Bats (Chiroptera)

Bats are the only flying mammals and have well developed navigation abilities for 3D-space. Even bats with comparatively small home ranges cover much larger territories than rodents, and long-distance migration by some species is unique among small mammals. Adult proliferation of neurons, i.e., adult neurogenesis, in the dentate gyrus of rodents is thought to play an important role in spatial memory and learning, as indicated by lesion studies and recordings of neurons active during spatial behavior. Assuming a role of adult neurogenesis in hippocampal function, one might expect high levels of adult neurogenesis in bats, particularly among fruit- and nectar-eating bats in need of excellent spatial working memory. The dentate gyrus of 12 tropical bat species was examined immunohistochemically, using multiple antibodies against proteins specific for proliferating cells (Ki-67, MCM2), and migrating and differentiating neurons (Doublecortin, NeuroD). Our data show a complete lack of hippocampal neurogenesis in nine of the species (Glossophaga soricina, Carollia perspicillata, Phyllostomus discolor, Nycteris macrotis, Nycteris thebaica, Hipposideros cyclops, Neoromicia rendalli, Pipistrellus guineensis, and Scotophilus leucogaster), while it was present at low levels in three species (Chaerephon pumila, Mops condylurus and Hipposideros caffer). Although not all antigens were recognized in all species, proliferation activity in the subventricular zone and rostral migratory stream was found in all species, confirming the appropriateness of our methods for detecting neurogenesis. The small variation of adult hippocampal neurogenesis within our sample of bats showed no indication of a correlation with phylogenetic relationship, foraging strategy, type of hunting habitat or diet. Our data indicate that the widely accepted notion of adult neurogenesis supporting spatial abilities needs to be considered carefully. Given their astonishing longevity, certain bat species may be useful subjects to compare adult neurogenesis with other long-living species, such as monkeys and humans, showing low rates of adult hippocampal neurogenesis

Matching Morphology and Diet in the Disc-Winged Bat Thyroptera tricolor (Chiroptera)

The dietary niche and morphological adaptations of a species should be highly correlated. However, conflicting selective pressures may make predictions about diet difficult without additional knowledge of a species' life history. We tested the reliability of predicting a bat's diet from its wing morphology using data for Spix's disk-winged bat (Thyroptera tricolor). The species had been predicted to fall within either the aerial hawking or gleaning foraging group. We compared the results of a theoretical (canonical discriminant function analysis of morphology) and an applied (analysis of droppings) method of diet determination. Our results place T. tricolor in the gleaning functional group with a 77% probability according to morphology. Correspondingly, a large proportion of the diverse diet consisted of nonflying prey, such as spiders, insect larvae, and other silent prey, which should be difficult to detect using echolocation. Although some flying prey were taken, it is clear that T. tricolor regularly gleans prey from surfaces, indicating that for this species, morphology is a useful indicator of diet. However, the breadth of the diet; the high proportion of jumping spiders, leafhoppers, and insect larvae; and the extremely small size of prey were unique features of the diet that could not be predicted from morphology alone. Thus, although comparative statistical methods and the analysis of wing morphology may be helpful to predict the general ecological niche, only detailed investigation of the life history may yield the detail needed for understanding the link between morphology and ecology of individual specie

Estudio de una escultura con inscripción ibérica procedente del santuario del Cerro de los Santos

La línea de trabajo sobre imagen en la cultura ibérica ha aportado a la arqueología ibérica excelentes resultados, tanto desde el punto de vista de la dinamización teórica de la disciplina, como en su aplicación concreta al estudio y la interpretación de determinados programas iconográficos en sus contextos arqueológicos (OLMOS 1992, 1996; ARANEGUI 1997, entre otros). Uno de los sujetos de investigación de especial relevancia de esta línea ha sido la religiosidad y sus diversas manifestaciones. En este sentido, los exvotos ibéricos labrados en caliza y bronce (RUIZ BREMÓN 1989a; PRADOS1992), sin olvidar aquellos elaborados en terracota, representan un material de estudio privilegiado

Nutrition or Detoxification: Why Bats Visit Mineral Licks of the Amazonian Rainforest

Many animals in the tropics of Africa, Asia and South America regularly visit so-called salt or mineral licks to consume clay or drink clay-saturated water. Whether this behavior is used to supplement diets with locally limited nutrients or to buffer the effects of toxic secondary plant compounds remains unclear. In the Amazonian rainforest, pregnant and lactating bats are frequently observed and captured at mineral licks. We measured the nitrogen isotope ratio in wing tissue of omnivorous short-tailed fruit bats, Carollia perspicillata, and in an obligate fruit-eating bat, Artibeus obscurus, captured at mineral licks and at control sites in the rainforest. Carollia perspicillata with a plant-dominated diet were more often captured at mineral licks than individuals with an insect-dominated diet, although insects were more mineral depleted than fruits. In contrast, nitrogen isotope ratios of A. obscurus did not differ between individuals captured at mineral lick versus control sites. We conclude that pregnant and lactating fruit-eating bats do not visit mineral licks principally for minerals, but instead to buffer the effects of secondary plant compounds that they ingest in large quantities during periods of high energy demand. These findings have potential implications for the role of mineral licks for mammals in general, including humans

Metabolic costs of bat echolocation in a non-foraging context support a role in communication

The exploitation of information is a key adaptive behavior of social animals, and many animals produce costly signals to communicate with conspecifics. In contrast, bats produce ultrasound for auto-communication, i.e., they emit ultrasound calls and behave in response to the received echo. However, ultrasound echolocation calls produced by non-flying bats looking for food are energetically costly. Thus, if they are produced in a non-foraging or navigational context this indicates an energetic investment, which must be motivated by something. We quantified the costs of the production of such calls, in stationary, non-foraging lesser bulldog bats (Noctilio albiventris) and found metabolic rates to increase by 0.021 ± 0.001 J/pulse (mean ± standard error). From this, we estimated the metabolic rates of N. albiventris when responding with ultrasound echolocation calls to playbacks of echolocation calls from familiar and unfamiliar conspecific as well as heterospecific bats. Lesser bulldog bats adjusted their energetic investment to the social information contained in the presented playback. Our results are consistent with the hypothesis that in addition to orientation and foraging, ultrasound calls in bats may also have function for active communication