We explored behavioural adjustments made by parent house sparrows, Passer domesticus, when the nutritional condition of their dependent nestlings was improved experimentally. Male parents responded to artificially supplemented broods by increasing food deliveries, whereas female parents continued matching the already high rate of control females. Thus, parental care was not truncated in the fac...

—We tested for the presence of compensatory growth (i.e. faster age-specific growth) following ephemeral periods of food restriction in altricial nestlings using the House Sparrow (Passer domesticus) as a model species. To simulate periods of poor food conditions, we raised nestlings in captivity, fed them a synthetic diet, and held them at constant body mass for 48 h beginning on either day 3 ...

Social foragers can use either a 'producer' strategy, which involves searching for food, or a 'scrounger' strategy, which involves joining others' food discoveries. While producers rely on personal information and past experience, we may ask whether the tendency to forage as a producer is related to being a better learner. To answer this question, we hand-raised house sparrow (Passer domesticus...

When wild animals are brought into captivity for the first time, they frequently develop chronic stress symptoms. Animals can develop glucocorticoid dysregulation or changes in the sympathetic nervous system over the course of the first week in captivity. By blocking the action of epinephrine and norepinephrine using α- or β-blockers, we hoped to reduce the degree of chronic stress symptoms exh...

Two adaptationist hypotheses have been proposed to explain why stress, particularly elevation of stress hormones (i.e. glucocorticoids), tends to suppress immune functions. One is that immune suppression represents efforts to minimize autoimmune responses to self-antigens released as organisms cope with stressors (i.e. the autoimmune-avoidance hypothesis). The other is that immune suppression o...

Both neutral and adaptive evolutionary processes can cause population divergence, but their relative contributions remain unclear. We investigated the roles of these processes in population divergence in house sparrows (Passer domesticus) from Romania and Bulgaria, regions characterized by high landscape heterogeneity compared to Western Europe. We asked whether morphological divergence, comple...

We estimate the annual financial losses resulting from wildlife damage to major crops and livestock in Nebraska. For each wildlife species, the damage problem is presented along with a description of how the estimate was made. Field crop estimates include losses from Plains pocket gophers (Geomys bursarius), commensal rodents (Rattus norvegicus and Mus musculus), field rodents in grain fields (...