Habitat selection by Black kite breeders and floaters: Implications for conservation management of raptor floaters

Preserving large predators is important but challenging because these species are typically wide-ranging, select multiple habitats at different scales and often present spatial or habitat separation between the breeder and floater sectors of a population. In addition, most of our knowledge on raptor floaters' habitat requirements comes from large solitary species, whose floaters often occupy temporary settlement areas spatially separate from breeding locations. Here, we examine space and habitat use by a loosely colonial, wetland-dependent raptor, the Black kite (Milvus migrans), in a population where floaters co-exist with territory holders, enabling a direct comparison of their habitat preferences. The study was conducted in Doñana National Park (South-Western Spain), a seasonally drying marshland currently surrounded by intensive agriculture and rice-fields. Intensive radio-tracking revealed that breeders and floaters selected and avoided the same habitats despite a radical, four-to-eight fold difference in their home-range dimensions: all kites over-selected open habitats suitable for their aerial foraging modes and avoided woodland and farmland. These results suggest a continuum of raptor population structures ranging from solitary species whose floaters select different habitats than breeders and are concentrated in spatially separate settlement areas, to colonial and semi-social species whose floaters fully coexist with breeders with shared habitat preferences. Both extremes of this continuum will pose challenges for conservation management. In solitary species, special conservation efforts may be required to identify and manage temporary settlement areas, while in gregarious species, the larger ranges of floaters may expose them to different threats than breeders, whose occurrence and consequences may be subtle to identify. © 2013 Elsevier Ltd.Peer Reviewe

Uso dello spazio, selezione d' habitat e rotte migratorie del Nibbio bruno (Milvus migrans): uno studio con telemetria convenzionale e satellitare (2010)

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Performance evaluation of congestion control for CoAP in 6TiSCH networks

The Internet of Things (IoT) is making changes in everyday life. The same is happening in the world of industry, where sensor networks monitor industrial processes. These networks are composed of devices with limited computational capacity, memory and autonomy. In the Industrial Internet of Things (IIoT) reliability and low latency are required, to meet these requirements the 6TiSCH architecture has been defined by IETF (Internet Engineering Task Force). In this work we evaluate the performance of Constrained Application Protocol (CoAP) over 6TiSCH networks with default congestion control policy, specifically we assess the performance and the challenges that comes from the adoption of CoAP congestion control when employing with IEEE 802.15.4 Time Slotted Channel Hopping (TSCH) MAC Protocol. This protocol guarantees low latency and high reliability. The communication resources in 6TiSCH networks are managed by Scheduling Functions (SFs), the nodes manage the communication schedule in a distributed manner with Distributed SF in the 6TiSCH schedule, that continuously monitor the traffic to allocate resources. The results show that there is a problem with the way distributed SFs are conceived, the tested system had performance limitations due to a lack of slots dedicated to communication between nodes. Changes have been made to the SF, adding dedicated downward slots. The results show that with this modification there is an increase in performance. The changes have been implemented in Contiki-NG, and simulations have been performed on the Cooja network simulator

Raptor Nest Decorations Are a Reliable Threat Against Conspecifics

Supporting Online Material www.sciencemag.org/cgi/content/full/331/6015/327/DC1 Materials and Methods Figs. S1 to S3 Tables S1 to S9Individual quality is often signaled by phenotypic flags, such as bright plumage patches in birds. Extended phenotype signals can similarly show quality, but in these cases the signals are external to the individual, often taking the form of objects scavenged from the environment. Through multiple manipulative experiments, we showed that objects used for nest decoration by a territorial raptor, the black kite (Milvus migrans), act as reliable threats to conspecifics, revealing the viability, territory quality, and conflict dominance of the signaler. Our results suggest that animal- built structures may serve as signaling devices much more frequently than currently recognized.Peer reviewe