Movement ecology of a highly social and increasingly abundant bird species, and its consequences for individual fitness and plant dispersal

Currently In Progress
Movement of organisms is common to all life forms, playing a key role in many ecological, behavioral and evolutionary processes, strongly influencing human life and major global, environmental concerns.

Recent technological and conceptual advances in studying organismal movements have set the stage for the emergence of the movement ecology paradigm, which integrates the principal components of movement into a cohesive framework: the internal state of the organism, its motion and navigation capacities, the external abiotic and biotic factors affecting movement, and the resulting movement path.

Yet, a key challenge remains whether the recent technologies and concepts are sufficient to elucidate the mechanisms underlying movement of free-ranging organisms within real-life,complex ecosystems.

In this proposal, we focus on an animal species in the wild, the Eurasian Jackdaw (Corvus monedula; hereafter EJ), which is a highly social bird that eats various plant species.

This species has rapidly expanded in Israel, mostly over the last decade, becoming one of the most abundant bird species in many parts of the country.

This fact, as well as the intriguing social structure present in EJs, provides a unique opportunity to thoroughly assess the relative importance of movement, food supply, social interactions, and the interplay among them in determining the fitness of individual free-ranging birds, as well as the resulting consequences for spatial plant dynamics.

More specifically, we set five objectives for this project, to elucidate:

  • How social rank and food supply interact to determine movement of individual EJs.
  • How social structure, pair bonds and dominance determine EJ flock flight patterns.
  • How movement, social rank and food supply interact to determine individual EJ fitness (survival and reproductive success).
  • How movement of EJs shapes plant populations and communities.  Namely, by identifying the pool of plant species dispersed and consumed by EJs, determining the dispersal kernels they generate, quantifying their effectiveness as seed dispersers or predators, and developing a model to assess how the rapid increase in EJ abundance and range affects spatial plant dynamics.
  • How seed dispersal is affected by the social interactions among individual EJs.

To address these questions, we will utilize a variety of research tools including miniaturized GPS, RFID and proximity biotelemetry tags enabling accurate, long-term tracking; tri-axial acceleration sensors enabling behavior identification; high-speed video cameras that allow for analysis of flock flight; and advanced molecular tools facilitating plant and animal identification.

To our knowledge,the proposed research will be the first to integrate social behavior, movement and fitness of a free-ranging wild animal species, and to examine how these interactions affect population dynamics of plants.

This will contribute both to basic and applied research: to the former, by elucidating the mechanisms affecting movement and fitness, and how they shape plant population dynamics; and to the latter, by quantitatively assessing the potential impact of an increasingly abundant species on agriculture and nature conservation.