Consumption of Carnivores by Wolves: A Worldwide Analysis of Patterns and Drivers

The occurrence of carnivore species in wolf diet has been overlooked and poorly studied despite the potential implications for wolf ecology and wildlife management. We conducted an extensive literature review, focusing on 120 wolf diet studies worldwide to assess global patterns of carnivore consumption by wolves and their ecological and human-related determinants. We used a total of 143 sampling sites with data on the consumption of carnivores by wolves. In total, 35 carnivore species were reported to be consumed by wolves, comprising members of all taxonomic carnivore families represented within the gray wolf range. The carnivores were mostly limited to occasional consumption (<5% of wolf diet) but could account for as much as 25% in some study areas. The most frequently consumed carnivore species were those with reported scavenging behavior, belonging to medium-sized generalist canids. Generalized linear model (GLM) analysis revealed that higher magnitudes of carnivore consumption were related to nonprotected areas as well as lower occurrences of wild ungulates, domestic ungulates, and small mammals in wolf diet, while higher numbers of consumed carnivore species were related to nonprotected areas with low vegetation productivity and lower occurrences of domestic ungulates and small mammals in wolf diet. Our results suggest that carnivore consumption by wolves is driven by altered ecosystems and human-dominated landscapes, where mesopredator densities are often increased and prey densities decreased, which intensify competition and the need for alternative food sources.

An approach to illustrate the naturalness of the Brazilian Araucaria forest

The concept of “naturalness” can be associated with conservation status, resilience, and biodiversity. Its most common definition relates to the degree to which a resource is similar to its original state. Hence, we developed a naturalness assessment method for the Brazilian Araucaria forest. We used data collected within 145 systematically distributed plots over an area of ∼56 000 km2. We selected five indicators to compose a unified naturalness index: (i) evidence of human activities inside the forest stand; (ii) abundance of naturalness-indicator species; (iii) standard deviation of diameter at breast height (Sdbh); (iv) species diversity of the understory–natural regeneration layer; and (v) forest stand landscape metrics. We then calculated the Euclidean distance between the vector generated from the indicators of an ordinary forest stand and the vector generated from a theoretical reference forest (TRF) with maximum naturalness. The reduced Sdbh reflected the stands’ diminished structural diversity as result of historical logging and other ongoing human activities. Most stands presented average naturalness compared with the TRF. Besides the lack of data on undisturbed forests to thoroughly evaluate the naturalness index, evidence suggested that it summarized relevant forest attributes to the extent that protected areas presented greater naturalness than nonprotected areas.

Elevated trawling inside protected areas undermines conservation outcomes in a global fishing hot spot

Marine protected areas (MPAs) are increasingly used as a primary tool to conserve biodiversity. This is particularly relevant in heavily exploited fisheries hot spots such as Europe, where MPAs now cover 29% of territorial waters, with unknown effects on fishing pressure and conservation outcomes. We investigated industrial trawl fishing and sensitive indicator species in and around 727 MPAs designated by the European Union. We found that 59% of MPAs are commercially trawled, and average trawling intensity across MPAs is at least 1.4-fold higher as compared with nonprotected areas. Abundance of sensitive species (sharks, rays, and skates) decreased by 69% in heavily trawled areas. The widespread industrial exploitation of MPAs undermines global biodiversity conservation targets, elevating recent concerns about growing human pressures on protected areas worldwide.

Does capture method or the presence of aquatic protected areas influence the selective harvest of behavioural types in largemouth bass?

Selectively removing fish based on particular traits, such as body size, may shift trait abundance in the remaining population, resulting in a phenomenon called fisheries-induced evolution. Recently, there is growing interest in evaluating the effects of fisheries-induced evolution on fish behaviour. Aquatic protected areas (APAs) have been designated in some habitats in efforts to prohibit harvesting and maintain natural ranges of phenotypic variation for impacted species. Here, we attempted to test whether APAs that prohibit all forms of fishing have an evolutionary influence on adult largemouth bass (Micropterus salmoides) behaviour by investigating the relationship between capture method and behavioural type. Fish, caught via active (angling) and passive (hoop net) capture techniques in both protected (70+ year old APAs in eastern Ontario) and adjacent nonprotected areas, were subjected to standard tests of boldness (refuge emergence, general activity, and flight-initiation-distance). A behavioural syndrome characterized by consistent within-individual variation and correlation of boldness behaviours (activity and refuge emergence) was present. Our results provide evidence that APAs may promote behavioural diversification and protect traits selectively targeted by recreational angling.