Seabird distribution patterns observed with fishing vessel’s radar reveal previously undescribed sub-meso-scale clusters

Assali, Camille; Bez, Nicolas; Tremblay, Yann

doi:10.1038/s41598-017-07480-6

Cited by 14 publications

(17 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, the use of additional existing meteorological measuring platforms, such as wind profilers, is a promising direction to substantially increase our knowledge of aerial migration in different parts of the world (Weisshaupt et al 2018). We note that seabirds have been mostly tracked with radars from the coast, but recently a study showing seabird foraging movements and social interactions was done using radar on board a fishing vessel (Assali et al 2017). The use of shipborne radars for tracking bird migration across seas could allow for the exploration of novel research questions, such as the effects of human-induced food resources on migrating seabirds far from the shore.…”

Section: Increasing the Coverage Of Aeroecological Radar Studiesmentioning

confidence: 99%

Environmental effects on flying migrants revealed by radar

et al. 2019

View full text Add to dashboard Cite

Migratory animals are affected by various factors during their journeys, and the study of animal movement by radars has been instrumental in revealing key influences of the environment on flying migrants. Radars enable the simultaneous tracking of many individuals of almost all sizes within the radar range during day and night, and under low visibility conditions. We review how atmospheric conditions, geographic features and human development affect the behavior of migrating insects and birds as recorded by radars. We focus on flight initiation and termination, as well as in‐flight behavior that includes changes in animal flight direction, speed and altitude. We have identified several similarities and differences in the behavioral responses of aerial migrants including an overlooked similarity in the use of thermal updrafts by very small (e.g. aphids) and very large (e.g. vultures) migrants. We propose that many aerial migrants modulate their migratory flights in relation to the interaction between atmospheric conditions and geographic features. For example, aerial migrants that encounter crosswind may terminate their flight or continue their migration and may also drift or compensate for lateral displacement depending on their position (over land, near the coast or over sea). We propose several promising directions for future research, including the development and application of algorithms for tracking insects, bats and large aggregations of animals using weather radars. Additionally, an important contribution will be the spatial expansion of aeroecological radar studies to Africa, most of Asia and South America where no such studies have been undertaken. Quantifying the role of migrants in ecosystems and specifically estimating the number of departing birds from stopover sites using low‐elevation radar scans is important for quantifying migrant–habitat relationships. This information, together with estimates of population demographics and migrant abundance, can help resolve the long‐term dynamics of migrant populations facing large‐scale environmental changes.

show abstract

Section: Increasing the Coverage Of Aeroecological Radar Studiesmentioning

confidence: 99%

Environmental effects on flying migrants revealed by radar

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The open ocean of the tropics may offer particular challenges for aerial predators; hydrographic features do not function to concentrate prey in the same way as on the continental shelf, and the spatial predictability of prey is lower than in high latitude waters (Bost et al, 2009;Assali et al, 2017). The capacity of aerial predators to see each other and interpret the behavior of conspecifics and other seabirds is potentially important in providing cues.…”

Section: Tropical Oceansmentioning

confidence: 99%

“…We need additional data on interactions among seabirds and other marine predators. Understanding patterns in the aggregation of birds have important implications for designation of protected areas, and management of species, particularly management of populations for recovery (Assali et al, 2017).…”

Section: Future Researchmentioning

confidence: 99%

Positive Interactions among Foraging Seabirds, Marine Mammals and Fishes and Implications for Their Conservation

Veit

Harrison

2017

Front. Ecol. Evol.

View full text Add to dashboard Cite

There is increasing recognition of the importance of "positive interactions" among species in structuring communities. For seabirds, an important kind of positive interaction is the use of birds of the same species, birds of other species, and other marine predators such as cetaceans, seals and fishes as cues to the presence of prey. The process by which a single bird uses, say, a feeding flock of birds as a cue to the presence of prey is called "local enhancement" or "facilitation." There are subtly different uses of each of these terms, but the issue we address here is the ubiquity of positive interactions between seabirds and other marine predators when foraging at sea, and whether as a result of their associations the feeding success, and therefore presumably the fitness, of individual seabirds is increased. If this contention is true, then it implies that conservation of any one species of seabird must take into consideration the status and possible conservation of those species that the focal species uses as a cue while foraging. For example, conservation of great shearwaters (Ardenna gravis), which often feed over tuna (e.g., Thunnus) schools, should take in to consideration conservation of tuna. Ecosystem management depends on understanding the importance of such processes; the loss of biodiversity, and the consequent threat to foraging success, may be a substantial threat to the stability of marine ecosystems.

show abstract

“…At least under calm weather conditions, birds interacting with fishing vessels (Fig. 6, Assali et al 2017) or bats foraging over the open sea (Ahlén et al 2009) can be observed by marine radar. Many seabird species feed in large numbers at fishing vessels on offal or bait, where their high mortality is the main threat to populations worldwide (Phillips et al 2016).…”

Section: Foraging and Habitat Usementioning

confidence: 99%

Perspectives and challenges for the use of radar in biological conservation

et al. 2019

View full text Add to dashboard Cite

Radar is at the forefront for the study of broad‐scale aerial movements of birds, bats and insects and related issues in biological conservation. Radar techniques are especially useful for investigating species which fly at high altitudes, in darkness, or which are too small for applying electronic tags. Here, we present an overview of radar applications in biological conservation and highlight its future possibilities. Depending on the type of radar, information can be gathered on local‐ to continental‐scale movements of airborne organisms and their behaviour. Such data can quantify flyway usage, biomass and nutrient transport (bioflow), population sizes, dynamics and distributions, times and dimensions of movements, areas and times of mass emergence and swarming, habitat use and activity ranges. Radar also captures behavioural responses to anthropogenic disturbances, artificial light and man‐made structures. Weather surveillance and other long‐range radar networks allow spatially broad overviews of important stopover areas, songbird mass roosts and emergences from bat caves. Mobile radars, including repurposed marine radars and commercially dedicated ‘bird radars’, offer the ability to track and monitor the local movements of individuals or groups of flying animals. Harmonic radar techniques have been used for tracking short‐range movements of insects and other small animals of conservation interest. However, a major challenge in aeroecology is determining the taxonomic identity of the targets, which often requires ancillary data obtained from other methods. Radar data have become a global source of information on ecosystem structure, composition, services and function and will play an increasing role in the monitoring and conservation of flying animals and threatened habitats worldwide.

show abstract

Seabird distribution patterns observed with fishing vessel’s radar reveal previously undescribed sub-meso-scale clusters

Cited by 14 publications

References 47 publications

Environmental effects on flying migrants revealed by radar

Environmental effects on flying migrants revealed by radar

Positive Interactions among Foraging Seabirds, Marine Mammals and Fishes and Implications for Their Conservation

Perspectives and challenges for the use of radar in biological conservation

Contact Info

Product

Resources

About