Nested vulnerability: exploring cross-scale linkages and vulnerability teleconnections in Mexican and Vietnamese coffee systems

Analyses of the vulnerability of farm populations and food systems to exogenous change, whether in relation to climatic extremes, market shocks, epidemics or other concerns, have typically been approached through a focus on the place of food production or the specific sub-sector exposed to stress. Relatively little attention has been paid to the ways in which national institutions, history and social expectations transform the same signals of global change into very different outcomes in distinct geographic contexts. The channels that convey signals of change from the global to the local may also work in reverse, connecting the responses and choices of households in one geographic context to outcomes and choices of other households in quite distant places. We draw from recent case studies of farm-level vulnerability and livelihood security in Mexico and Vietnam to demonstrate that coffee smallholders’ independent responses to the risks and opportunities associated with global scale economic and environmental change, are teleconnected and thus can create feedbacks which in turn affect the present and future vulnerabilities of other smallholders around the globe.     

A Myanmar amber cockroach with protruding feces contains pollen and a rich microcenosis

Several hypotheses have been proposed to explain the mechanisms responsible for maintenance of host-specific gentes in the common cuckoo (Cuculus canorus). Some of them expect that when adult cuckoos return to lay their eggs to their natal site (natal philopatry hypothesis) or habitat in which they were reared (habitat-imprinting hypothesis), there is a higher probability of finding nests of the host species by which they were reared. Since published evidence is ambiguous, we here evaluate the natal philopatry and habitat-imprinting hypotheses using information on habitat homogeneity and cross-continental long-term ringing data. We found no evidence for the natal philopatry hypothesis—instead of returning to their natal site, juvenile cuckoos exhibited longer dispersal movements than adults, and the difference was even larger in comparison with a wide array of cuckoo host species. On the contrary, we found support for the habitat-imprinting hypothesis—juvenile cuckoos followed similar levels of natal habitat homogeneity at 5- and 25-km scale when returning to breed in the next years. Our results suggest that preference for the particular habitat structures may help cuckoos to find appropriate hosts.