Bridging the research implementation gap – Identifying cost-effective protection measures for Montagu’s harrier nests in Spanish farmlands

Abstract

Expensive active management programs are increasing worldwide, while resources for conservation remain scarce. There is a need to evaluate management actions, so that scarce resources are used more cost-effectively. We evaluate the effectiveness of alternative interventions to protect Montagu´s harrier nests in Spanish farmlands. The species is under intensive management across Europe owing to high rates of nest destruction during mechanical harvesting operations. We use a novel approach, combining Latin hypercube sampling and population viability analysis in order to evaluate the impact of alternative protection interventions on populations' persistence across a whole range of resource allocation scenarios. We also report estimates of financial management costs for different protection interventions.Our results clearly show that, in absence of nest protection, Spanish harrier populations would collapse to levels close to extinction within 20 years. The most cost-effective protection measures among those evaluated were the relocation or removal of the chicks and harvest delay, although this varied according to region and context. Interestingly, retention of a small un-harvested buffer around the nest, despite being widely implemented across Spain, was less cost-effective than the other two measures.Overall, we provide evidence about what measure is most effective in each studied region and what proportion of nests should be protected with such effective measure to maintain viable populations in the medium term. We also estimate how much this effort would cost to local administrations. This is a clear example of how cost-effectiveness analyses link to applied conservation and resource allocation.Key-words: conservation spending, ecological economics, Circus pygargus, evidence-based conservation, raptors, agricultural intensification Highlights:• We assess cost-effectiveness of nest protection for Montagu's harrier in farmland • We used population viability analysis to evaluate effectiveness of actions • In absence of nest protection, most populations are deemed to extinction • Most cost-effective measures varied among regions• Our approach can help allocating resources to protect regional populations 3

Conservation Traps and Long‐Term Species Persistence in Human‐Dominated Systems

“…Panel (C) shows the estimated Lleida population size after 20 years (solid black line) depending on the proportion of protected nests (modified from Santangeli et al . ). The dashed horizontal line indicates population size at the beginning of the simulation period (current population size: 65 pairs, or 140 individuals assuming 10% nonbreeding).…”

The Financial Return from Measuring Impact

“…), a separate study of this species in Spain (Santangeli et al . ), and protection of nests of the white‐tailed eagle Haliaeetus albicilla in Finnish forests (Santangeli et al . ).…”

“…Effectiveness of each protection measure was quantified, within each study, by comparing the modeled productivity (i.e., the number of fledglings per nest; see respective studies: Santangeli et al . (, , ) of each intervention against the productivity of unprotected nests in each study system. The added benefit of each intervention was derived by making the difference between productivity from protected and unprotected nests.…”

“…The PhD thesis was based on five studies, but here we consider only those three where interventions required monetary investment. These three studies considered protection of Montagu's harrier nests Circus pygargus in farmland of France (Santangeli et al 2015), a separate study of this species in Spain (Santangeli et al 2014), and protection of nests of the white-tailed eagle Haliaeetus albicilla in Finnish forests ).…”

“…For the two studies in France and Spain, the costs for each implemented intervention were given in the respective publications. In Spain, costs were quantified by determining expenses for the additional fieldwork necessary to apply the protection measure and the direct implementation costs, such as compensation to a farmer for delaying harvest; see more details in Santangeli et al (2014). Intervention costs in Spain may vary according to nest aggregation and crop productivity.…”