Effects of spatial autocorrelation and sampling design on estimates of protected area effectiveness

Estimating the effectiveness of protected areas (PAs) in reducing deforestation is useful to support decisions on whether to invest in better management of areas already protected or to create new ones. Statistical matching is commonly used to assess this effectiveness, but spatial autocorrelation and regional differences in protection effectiveness are frequently overlooked. Using Colombia as a case study, we employed statistical matching to account for confounding factors in park location and accounted for for spatial autocorrelation to determine statistical significance. We compared the performance of different matching procedures—ways of generating matching pairs at different scales—in estimating PA effectiveness. Differences in matching procedures affected covariate similarity between matched pairs (balance) and estimates of PA effectiveness in reducing deforestation. Independent matching yielded the greatest balance. On average 95% of variables in each region were balanced with independent matching, whereas 33% of variables were balanced when using the method that performed worst. The best estimates suggested that average deforestation inside protected areas in Colombia was 40% lower than in matched sites. Protection significantly reduced deforestation, but PA effectiveness differed among regions. Protected areas in Caribe were the most effective, whereas those in Orinoco and Pacific were least effective. Our results demonstrate that accounting for spatial autocorrelation and using independent matching for each subset of data is needed to infer the effectiveness of protection in reducing deforestation. Not accounting for spatial autocorrelation can distort the assessment of protection effectiveness, increasing type I and II errors and inflating effect size. Our method allowed improved estimates of protection effectiveness across scales and under different conditions and can be applied to other regions to effectively assess PA performance.     

A Scottish approach to training for the unemployed: work‐start Ltd., Dundee

This article discusses the structure and performance of Work‐Start Ltd., a company located in Dundee and providing training for the unemployed. The company has attracted national and international attention by its innovative approach. Set up to meet the specific problems of peripheral housing estates, it is now responding to rapid changes in the local labour market.     

Desperado siblings: uncontrollably aggressive junior chicks

According to the desperado sibling hypothesis, chicks of obligately siblicidal species kill their junior broodmates as early as possible because junior broodmates face dire ecological prospects and are consequently predisposed to aggressively overthrow elder broodmates by all-out aggression. The agonistic behavior of junior chicks is virtually unknown because they die so young. We investigated the agonistic behavior of hypothetical desperados by fostering junior brown boobies (Sula leucogaster, an obligately siblicidal species) into nests of the blue-footed booby (S. nebouxii, a facultatively siblicidal species) containing an older singleton blue-foot chick. Controls were junior blue-footed boobies fostered into the same situation. Junior brown boobies were 7 times more aggressive than controls and most of them dominated their elder and larger nestmates. Four of nine brown booby juniors showed relentless aggression, delivering up to 711 pecks, bites and pushes (including "expulsion pushes") per hour, thereby overwhelming nestmates 90% heavier and permanently expelling one of them from the nest. Similarly, in natural broods of two surviving brown booby chicks, the losing chick was 13 times as aggressive as blue-foot subordinates, up to at least age 7 weeks. Contrast of the two species of booby suggests the evolution of agonistic roles within broods may be partly driven by selection on potential victims to express a level and type of aggressiveness appropriate to their status-related ecological prospects.     

Parent-offspring cooperation in the blue-footed boody (Sula nebouxii): social roles in infanticial brood reduction

Summary Reproduction in the blue-footed boody was examined for evidence of parent-offspring conflict over infanticidal reduction of the brood. Parental investment was analysed by measuring clutch characteristics, and chick growth and mortality in four seasons. Direct observations were made of behavioral development to determine the social roles of family members. The modal clutch was two similar-sized eggs, which hatched 4.0 days apart due to a 5.1-day laying interval and immediate incubation of the first egg. On average, senior chicks grew faster than their sibs in years of good or poor growth (Fig. 2), maintaining the initial size disparity for at least 65 days (Fig. 1). Differential mortality of junior chicks was associated not with poor personal growth, but with a 20–25% weight deficiency of the senior sib, implying siblicidal brood reduction triggered at a weight threshold. Senior chicks established behavioral dominance through low-frequency pecking, but ordinarily did not eliminate their sibs nor substantially suppress their begging (Fig. 3), even when their own growth was 16% below potential. Parents fed dominant chicks more frequently than subordinates, but did not intervene in inter-sib aggression, even when it reached a siblicidal level. The weight and possibly the dominance relation between sibs was inverted in 12% of pairs. The theoretical prediction of conflict over elimination of the junior chick was not supported; rather, parents and senior chick cooperate, as if their fitness interests were congruent. Further, provisional tolerance of the junior chick by its underweight senior sib is consistent with self-sacrifice to increase the latter's inclusive fitness.