BREEDING PERFORMANCE IN RELATION TO NEST-SITE SUBSTRATUM IN A BUFF-NECKED IBIS (THHWTICUS CA UDATUS) POPULATION IN PATAGONIA'

Abstract. In northern Argentinean Patagonia, Buff-necked Ibis (Theristicus caudatus) nest on different substrata: cliffs, trees, and marsh vegetation. According to the ideal-free distribution hypothesis, this polymorphism may be due to the occupation ofthe best breeding habitats by dominant individuals and the relegation of the subdominant birds to marginal substrata with a lower probability of achieving successful breeding. We investigated whether there were any variations in the breeding performance among colonies and whether these variations were related to the breeding substratum. Laying date varied from the third week of September to the last week of October, laying occurring earlier in colonies at lower elevations. Clutch size per colony varied between 1.8 and 2.0 (X 1.9, n = 106), but significant differences were not detected among colonies. Brood size per colony varied significantly, ranging between 1.3 and 2.0 (52 = 1.8, n = 164). The substratum of breeding did not influence variations in any of these three parameters. The physical condition of the chicks did not vary among substrata, but there was inter-colony variation in broods of two chicks. Daily rates of nest losses were similar among colonies reaching 6.2% (n = 856) during incubation and 1.4% (n = 966) during the nestling period. Brood reduction was low; the daily mortality rate of chicks (0.7%, n = 934) did not vary among colonies. The most common known cause of nest and chick losses was predation. These results indicate that breeding success varied only slightly from one colony to the other and that these variations are independent of the nesting substratum. In consequence, birds would not prefer one substratum over another

Priority areas for conservation alone are not a good proxy for predicting the impact of renewable energy expansion

Non peer reviewe

Presumed killers? Vultures, stakeholders, misperceptions, and fake news

Vultures and condors are among the most threatened avian species in the world due to the impacts of human activities. Negative perceptions can contribute to these threats as some vulture species have been historically blamed for killing livestock. This perception of conflict has increased in recent years, associated with a viral spread of partial and biased information through social media and despite limited empirical support for these assertions. Here, we highlight that magnifying infrequent events of livestock being injured by vultures through publically shared videos or biased news items negatively impact efforts to conserve threatened populations of avian scavengers. We encourage environmental agencies, researchers, and practitioners to evaluate the reliability, frequency, and context of reports of vulture predation, weighing those results against the diverse and valuable contributions of vultures to environmental health and human well-being. We also encourage the development of awareness campaigns and improved livestock management practices, including commonly available nonlethal deterrence strategies, if needed. These actions are urgently required to allow the development of a more effective conservation strategy for vultures worldwide.Peer reviewe

Rethinking megafauna

Concern for megafauna is increasing among scientists and non-scientists. Many studies have emphasized that megafauna play prominent ecological roles and provide important ecosystem services to humanity. But, what precisely are “megafauna”? Here we critically assess the concept of megafauna and propose a goal-oriented framework for megafaunal research. First, we review definitions of megafauna and analyze associated terminology in the scientific literature. Second, we conduct a survey among ecologists and paleontologists to assess the species traits used to identify and define megafauna. Our review indicates that definitions are highly dependent on the study ecosystem and research question, and primarily rely on ad hoc size-related criteria. Our survey suggests that body size is crucial, but not necessarily sufficient, for addressing the different applications of the term megafauna. Thus, after discussing the pros and cons of existing definitions, we propose an additional approach by defining two function-oriented megafaunal concepts: “keystone megafauna” and “functional megafauna”, with its variant “apex megafauna”. Assessing megafauna from a functional perspective could challenge the perception that there may not be a unifying definition of megafauna that can be applied to all eco-evolutionary narratives. In addition, using functional definitions of megafauna could be especially conducive to cross-disciplinary understanding and cooperation, improvement of conservation policy and practice, and strengthening of public perception. As megafaunal research advances, we encourage scientists to unambiguously define how they use the term “megafauna” and to present the logic underpinning their definition

Lead Ammunition and Illegal Poisoning: Further International Agreements Are Needed to Preserve Vultures and the Crucial Sanitary Service They Provide

Peer reviewe

European vultures' altered behaviour

Correspondence.Peer Reviewe