fear of predation can induce profound changes in the behaviour and physiology of prey species even if predator encounters are infrequent. for echolocating toothed whales, the use of sound to forage exposes them to detection by eavesdropping predators, but while some species exploit social defences or produce cryptic acoustic signals, deep-diving beaked whales, well known for mass-strandings induced by navy sonar, seem enigmatically defenceless against their main predator, killer whales. Here we test the hypothesis that the stereotyped group diving and vocal behaviour of beaked whales has benefits for abatement of predation risk and thus could have been driven by fear of predation over evolutionary time. Biologging data from 14 Blainville's and 12 Cuvier's beaked whales show that group members have an extreme synchronicity, overlapping vocal foraging time by 98% despite hunting individually, thereby reducing group temporal availability for acoustic detection by killer whales to <25%. Groups also perform a coordinated silent ascent in an unpredictable direction, covering a mean of 1 km horizontal distance from their last vocal position. This tactic sacrifices 35% of foraging time but reduces by an order of magnitude the risk of interception by killer whales. these predator abatement behaviours have likely served beaked whales over millions of years, but may become maladaptive by playing a role in mass strandings induced by man-made predator-like sonar sounds. Deep-diving marine mammals are expected to maximise time spent foraging in deep prey layers to offset the energetic and physiological costs of diving 1. But Cuvier's and Blainville's beaked whales (Ziphius cavirostris and Mesoplodon densirostris, respectively) employ a diving behaviour unlike that of other deep-diving toothed whales: they restrict echolocation to the deepest part of long and deep foraging dives that are typically followed by extended series of shallower and silent non-foraging dives that result in less than 20% of time devoted to biosonar-mediated foraging 2-5. Further, these species ascend slowly and silently from deep dives at a low pitch angle 2. This unusual and costly diving style has been interpreted as serving to mitigate decompression sickness or to accommodate lactate build up from foraging dives that may exceed the aerobic dive limit 6 , but, see 7. However, satisfactory physiological mechanisms to support these interpretations have yet to be found. When other toothed whales dive to similar depths, they do not display such a diving behaviour: both pilot whales that are similar in size to these beaked whales and the larger sperm whales ascend nearly vertically from their deep foraging dives 8,9 and often emit calls during the ascent to mediate reunion with non-diving group members 10-13. Because the highly stereotyped group diving and vocal behaviour of beaked whales is difficult to explain by foraging niche or physiology 2 an alternate proposition is that it serves to abate predation risk 2,4,14. Fear of predation can induce profound...

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Se presentan los resultados de la identificación del material de la familia Serpulidae (Polychaeta) recolectado en la campaña oceanográfica Fauna II, así como la revisión de citas de presencia íbero-balear desde el catálogo de poliquetos más reciente (Ariño, 1987). Se identificaron 16 especies pertenecientes a 10 géneros, además de la primera cita íbero-balear de una quimera bioperculada (Ten Hove & Ben-Eliahu, 2005) de la especie Hydroides norvegicus Gunnerus, 1768. En cuanto a la revisión del catálogo se mencionan 65 especies, actualizando el nombre de 20 de ellas y añadiendo cinco especies ausentes en el catálogo de Ariño (1987): Hydroides stoichadon Zibrowius, 1971, Laeospira corallinae (de Silva & Knight-Jones, 1962), Serpula cavernicola Fassari & Mòllica, 1991, Spirobranchus lima (Grube, 1862) y Spirorbis inornatus L’Hardy & Quièvreux, 1962. Se cita por primera vez Vermiliopsis monodiscus Zibrowius, 1968 en el Atlántico ibérico y a partir de la bibliografía consultada, se muestra la expansión en la distribución íbero-balear de Hydroides dianthus (Verrill, 1873) y de H. stoichadon.

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Participatory research (PR) has been analyzed and documented from different points of view, with emphasis on the benefits generated for farmers. The effect of PR on organizational learning has, however, received little attention. This paper analyzes the interaction between a research and a development institution, the International Potato Center (CIP) and CARE in Peru, respectively, and makes the case that PR can contribute to creating a collaborative learning environment among organizations. The paper describes the evolution of the inter-institutional collaborative environment between the two institutions for more than a decade, including an informationtransfer period (1993)(1994)(1995)(1996), an action-learning period (1997)(1998)(1999)(2000)(2001)(2002), and a social-learning period (2003)(2004)(2005)(2006)(2007). Several lessons learned from each period are described, as are changes in institutional contexts and stakeholders' perceptions. The case shows that research and development-oriented organizations can interact fruitfully using PR as a mechanism to promote learning, flexibility in interactions, and innovation. Interactions foster the diffusion of information and the sharing of tacit knowledge within and between organizations, which in turn influences behavior. However, the paper also argues that long-term inter-organizational interactions are needed to facilitate learning, which can be used to influence the way organizations implement their interventions in a constantly changing environment.