Relationship, Choice, Health, and Typologies of Unpaid Care Labor for Older Adults.

Providing unpaid care labor to older adult friends and relatives is associated with deleterious health outcomes, especially among persons who feel they have no choice when taking on care responsibilities. We used hierarchical cluster analysis and structural equation modeling of data from the National Alliance for Caregiving's Caregiving in the U.S. 2015 Survey to explore choice-outcome relationships. We identified three distinct care typologies, hands-on, household, and managerial care. Perceived lack of choice predicted emotional stress directly and indirectly through household and managerial care; predicted physical strain directly and indirectly through all care typologies; but only predicted negative health impact indirectly through mediation. Lack of choice had greater direct effects on emotional stress and negative health impact for adult-descendants compared to participants with other relationships with recipients, for whom the effects of lack of choice on outcomes were mediated through household and managerial care.

Acoustic profiling in a complexly social species, the American crow: caws encode information on caller sex, identity, and behavioural context.

Previous research on inter-individual variation in the calls of corvids has largely been restricted to single call types, such as alarm or contact calls, and has rarely considered the effects of age on call structure. This study explores structural variation in a contextually diverse set of "caw" calls of the American crow (Corvus brachyrhynchos), including alarm, foraging recruitment and territorial calls, and searches for structural features that may be associated with behavioural context and caller sex, age, and identity. Automated pitch detection algorithms are used to generate 23 pitch-related and spectral parameters for a collection of caws from 18 wild, marked crows. Using principal component analysis and mixed models, we identify independent axes of acoustic variation associated with behavioural context and with caller sex, respectively. We also have moderate success predicting caller sex and identity from call structure. However, we do not find significant acoustic variation with respect to caller age.