  Understanding how an extinction event affects ecosystem is fundamental to
biodiversity conservation. For this reason, food web response to species loss
has been investigated in several ways in the last years. Several studies
focused on secondary extinction due to biodiversity loss in a bottom-up
perspective using in-silico extinction experiments in which a single species is
removed at each step and the number of secondary extinctions is recorded. In
these binary simulations a species goes secondarily extinct if it loses all its
resource species, that is, when the energy intake is zero. This pure
topological statement represents the best case scenario. In fact a consumer
species could go extinct losing a certain fraction of the energy intake and the
response of quantitative food webs to node loss could be very different with
respect to simple binary predictions. The goal of this paper is to analyze how
patterns of secondary extinctions change when higher species sensitivity are
included in the analyses. In particular, we explored how food web secondary
extinction, triggered by the removal of most connected nodes, varies as a
function of the energy intake threshold assumed as the minimum needed for
species persistence. As we will show, a very low increase of energy intake
threshold stimulates a disproportionate growth of secondary extinction.
