scholarly journals Isolating the roles of movement and reproduction on effective connectivity alters conservation priorities for an endangered bird

2018 ◽  
Vol 115 (34) ◽  
pp. 8591-8596 ◽  
Author(s):  
Ellen P. Robertson ◽  
Robert J. Fletcher ◽  
Christopher E. Cattau ◽  
Bradley J. Udell ◽  
Brian E. Reichert ◽  
...  
Keyword(s):  
Effective Connectivity ◽  
Conservation Strategies ◽  
Conservation Priorities ◽  
Snail Kite ◽  
Mobile Species ◽  
Successful Reproduction ◽  
Hierarchical Levels ◽  
Rostrhamus Sociabilis ◽  
Breeding Attempt ◽  
Do So

Movement is important for ecological and evolutionary theory as well as connectivity conservation, which is increasingly critical for species responding to environmental change. Key ecological and evolutionary outcomes of movement, such as population growth and gene flow, require effective dispersal: movement that is followed by successful reproduction. However, the relative roles of movement and postmovement reproduction for effective dispersal and connectivity remain unclear. Here we isolate the contributions of movement and immigrant reproduction to effective dispersal and connectivity across the entire breeding range of an endangered raptor, the snail kite (Rostrhamus sociabilis plumbeus). To do so, we unite mark–resight data on movement and reproduction across 9 years and 27 breeding patches with an integrated model that decomposes effective dispersal into its hierarchical levels of movement, postmovement breeding attempt, and postmovement reproductive success. We found that immigrant reproduction limits effective dispersal more than movement for this endangered species, demonstrating that even highly mobile species may have limited effective connectivity due to reduced immigrant reproduction. We found different environmental limitations for the reproductive component of effective dispersal compared with movement, indicating that different conservation strategies may be needed when promoting effective dispersal rather than movement alone. We also demonstrate that considering immigrant reproduction, rather than movement alone, alters which patches are the most essential for connectivity, thereby changing conservation priorities. These results challenge the assumption that understanding movement alone is sufficient to infer connectivity and highlight that connectivity conservation may require not only fostering movement but also successful reproduction of immigrants.

scholarly journals The persistence in time of distributional patterns in marine megafauna impacts zonal conservation strategies

2019 ◽  
Author(s):  
C. Lambert ◽  
G. Dorémus ◽  
V. Ridoux
Keyword(s):  
Species Distribution ◽  
Habitat Model ◽  
Spatial Extent ◽  
Conservation Strategies ◽  
Distribution Data ◽  
Bay Of Biscay ◽  
Mobile Species ◽  
Distributional Patterns ◽  
Marine Megafauna ◽  
Mpa Network

AbstractThe main type of zonal conservation approach corresponds to Marine Protected Areas (MPAs), which are spatially defined and generally static entities aiming at the protection of some target populations by the implementation of a management plan. For highly mobile species the relevance of an MPA over time might be hampered by temporal variations in distributions or home ranges. In the present work, we used habitat model-based predicted distributions of cetaceans and seabirds within the Bay of Biscay from 2004 to 2017 to characterise the aggregation and persistence of mobile species distributional patterns and the relevance of the existing MPA network. We explored the relationship between population abundance and spatial extent of distribution to assess the aggregation level of species distribution. We used the smallest spatial extent including 75% of the population present in the Bay of Biscay to define specific core areas of distributions, and calculated their persistence over the 14 studied years. We inspected the relevance of the MPA network with respect to aggregation and persistence. We found that aggregation and persistence are two independent features of marine megafauna distributions. Indeed, strong persistence was shown in both aggregated (bottlenose dolphins, auks) and loosely distributed species (northern gannets), while some species with aggregated distributions also showed limited year-to-year persistence in their patterns (black-legged kittiwakes). We thus have demonstrated that both aggregation and persistence have potential impact on the amount of spatio-temporal distributional variability encompassed within static MPAs. Our results exemplified the need to have access to a minimal temporal depth in the species distribution data when aiming to designate new site boundaries for the conservation of mobile species.

scholarly journals Coalescence times, life history traits and conservation concerns: an example from four coastal shark species from the Indo-Pacific

2021 ◽  
Author(s):  
Pierre Lesturgie ◽  
Serge Planes ◽  
Stefano Mona
Keyword(s):  
Population Structure ◽  
Life History ◽  
Life History Traits ◽  
New Caledonia ◽  
Demographic History ◽  
Conservation Strategies ◽  
Shark Species ◽  
Effective Population ◽  
Demographic Models ◽  
Mobile Species

Dispersal abilities play a crucial role in shaping the extent of population genetic structure, with more mobile species being panmictic over large geographic ranges and less mobile ones organized in meta-populations exchanging migrants to different degrees. In turn, population structure directly influences the coalescence pattern of the sampled lineages, but the consequences on the estimated variation of the effective population size (Ne) over time obtained by means of unstructured demographic models remain poorly understood. However, this knowledge is crucial for biologically interpreting the observed Ne trajectory and further devising conservation strategies in endangered species. Here we investigated the demographic history of four shark species (Carharhinus melanopterus, Carharhinus limbatus, Carharhinus amblyrhynchos, Galeocerdo cuvier) with different degrees of endangered status and life history traits related to dispersal distributed in the Indo-Pacific and sampled off New Caledonia. We compared several evolutionary scenarios representing both structured (meta-population) and unstructured models and then inferred the Ne variation through time. By performing extensive coalescent simulations, we provided a general framework relating the underlying population structure and the observed Ne dynamics. On this basis, we concluded that the recent decline observed in three out of the four considered species when assuming unstructured demographic models can be explained by the presence of population structure. Furthermore, we also demonstrated the limits of the inferences based on the sole site frequency spectrum and warn that statistics based on linkage disequilibrium will be needed to exclude recent demographic events affecting meta-populations.

scholarly journals Water Levels Affect Nest Success of the Snail Kite in Florida: AIC and the Omission of Relevant Candidate Models

The Condor ◽  
2002 ◽  
Vol 104 (1) ◽  
pp. 208-215 ◽  
Author(s):  
Steven R. Beissinger ◽  
Noel F. R. Snyder
Keyword(s):  
Nest Success ◽  
A Priori ◽  
Information Criterion ◽  
Water Levels ◽  
Spatial Effects ◽  
Factors Affecting ◽  
Snail Kite ◽  
Water Conditions ◽  
Rostrhamus Sociabilis ◽  
Definition Of

Abstract Dreitz et al. (2001) analyzed the factors affecting nest success of the Snail Kite (Rostrhamus sociabilis) in Florida. They concluded that success was unrelated to water levels because Akaike's Information Criterion rated models with water-level terms as poor compared to other models. Their suite of candidate models, however, did not include models with area-specific differences in the way that water levels affect nest success. We believe that such differences should have been included among the a priori models examined, and that their best model is neither ecologically informative nor useful for management. Using the same statistical methods, we reanalyze Dreitz et al.'s data on nesting success from the five areas with sufficient years and nests for analysis (comprising 89% of their 1542 nests) and show that, when spatial effects of water levels are included, water levels have an important influence on nest success over the entire range of water levels, not just during low water conditions. Furthermore, Dreitz et al.'s definition of nesting attempts excluded nests found during the 10–21 day pre-laying period, when many nests fail. Thus, they overestimated nest success and underestimated the amount of nesting activity under low water conditions. Low water conditions occur relatively frequently throughout much of the kite's range, and under these conditions few kites nest and even fewer fledge young. The effects of low water extend well beyond nest success, causing many kites to forgo nesting altogether, shortening the breeding season, and decreasing the opportunity for multiple brooding. Los Niveles de Agua Afectan el Éxito de Nidos de Rostrhamus sociabilis en Florida: Criterio de Información de Akaike y la Omisión de Modelos Potenciales Relevantes Resumen. Dreitz et al. (2001) analizaron los factores que afectan el éxito de anidación de Rostrhamus sociabilis en Florida. Ellos concluyeron que el éxito no está relacionado con los niveles de agua porque según el Criterio de Información de Akaike, los modelos que incluían términos relacionados con el nivel de agua eran de poco valor en comparación con otros modelos. Sin embargo, entre los modelos evaluados no incluyeron aquellos con diferencias específicas de área en la manera en que los niveles de agua afectan el éxito de los nidos. Nosotros creemos que dichas diferencias han debido ser incluidas en los modelos evaluados a priori y que su mejor modelo no es ecológicamente informativo ni útil en términos de manejo. Utilizando los mismos métodos estadísticos, reanalizamos los datos de éxito de anidación de Dreitz et al. de las cinco áreas que tenían suficientes años y nidos para analizar (comprendiendo el 89% de sus 1542 nidos). Demostramos que cuando se incluyen los efectos espaciales de los niveles de agua, éstos tienen una influencia importante en el éxito de los nidos en todo el rango de niveles de agua (no sólo en condiciones de aguas bajas). Más aún, la definición de intentos de anidación empleada por Dreitz et al. excluyó a aquellos nidos encontrados durante el período de 10 a 21 días pre-postura, cuando muchos nidos fracasan. Por lo tanto, ellos sobreestimaron el éxito de los nidos y subestimaron la cantidad de actividad de anidación en condiciones de aguas bajas. Las condiciones de aguas bajas se presentan con relativa frecuencia en gran parte del rango de distribución de R. sociabilis. Bajo esas condiciones, pocos individuos anidan y aún menos crían polluelos exitosamente. Los efectos de aguas bajas se extienden más allá del éxito de los nidos, causando que muchos individuos totalmente renuncien a anidar, acortando la época reproductiva y reduciendo las oportunidades de tener múltiples nidadas.

scholarly journals The Natural History of Sydney

2011 ◽  
Vol 17 (4) ◽  
pp. 378
Author(s):  
Matt W Hayward
Keyword(s):  
Natural History ◽  
Conservation Strategies ◽  
Editorial Team ◽  
Zoological Society ◽  
Natural History Studies ◽  
History Information ◽  
History Of ◽  
Competitive Nature ◽  
Effective Conservation ◽  
Do So

AUSTRALIA’S relatively recent discovery by Europeans and rapid loss of traditional knowledge without documentation means the accumulated knowledge of our natural history is scant compared to other continents (e.g., search for publications on the top-order predators of each continent for confirmation). Yet, as Mike Archer highlights in the Foreword to this book, this natural history information is fundamental for us to develop effective conservation strategies. Instead of focusing on accumulating this information, the competitive nature of academia limits the value of publishing simple natural history studies because of the low impact such studies invariably have (see Paul Adam’s chapter), while conservation managers are too busy to publish their natural history research particularly while they receive such little incentive to do so. The Natural History of Sydney offers a valuable remedy to this problem and Dan Lunney and his Royal Zoological Society of NSW editorial team deliver once again in servicing the intellectual needs of Australian zoologists.

scholarly journals Using individual‐based movement information to identify spatial conservation priorities for mobile species

2019 ◽  
Vol 33 (6) ◽  
pp. 1426-1437 ◽  
Author(s):  
Ross G. Dwyer ◽  
Hamish A. Campbell ◽  
Richard D. Pillans ◽  
Matthew E. Watts ◽  
Barry J. Lyon ◽  
...  
Keyword(s):  
Conservation Priorities ◽  
Mobile Species

scholarly journals Recent increase in the distribution of the snail kite (Rostrhamus sociabilis) along the central Pacific Coast of México

2013 ◽  
Vol 84 (1) ◽  
pp. 388-391 ◽  
Author(s):  
Salvador Hernández-Vázquez ◽  
Ricardo Rodríguez-Estrella ◽  
Francisco Ramírez-Ortega ◽  
Juan Loera ◽  
Manuel Ortega
Keyword(s):  
Pacific Coast ◽  
Central Pacific ◽  
Snail Kite ◽  
Recent Increase ◽  
Rostrhamus Sociabilis

scholarly journals Coalescent times, life history traits and conservation concerns: an example from four shark species from the Indo-Pacific

2021 ◽  
Author(s):  
Pierre Lesturgie ◽  
Serge Planes ◽  
Stefano Mona
Keyword(s):  
Population Structure ◽  
Life History ◽  
Life History Traits ◽  
New Caledonia ◽  
Demographic History ◽  
Conservation Strategies ◽  
Shark Species ◽  
Effective Population ◽  
Demographic Models ◽  
Mobile Species

Dispersal abilities play a crucial role in shaping the extent of population genetic structure, with more mobile species being panmictic over large geographic ranges and less mobile ones organized in meta-populations exchanging migrants to different degrees. In turn, population structure directly influences the coalescent pattern of the sampled lineages, but the consequences on the estimated variation of the effective population size (Ne) over time obtained by means of unstructured demographic models remain poorly understood. However, this knowledge is crucial for biologically interpreting the observed Ne trajectory and further devising conservation strategies in endangered species. Here we investigated the demographic history of four shark species (Carharhinus melanopterus, Carharhinus limbatus, Carharhinus amblyrhynchos, Galeocerdo cuvier) with different degrees of endangered status and life history traits related to dispersal distributed in the Indo-Pacific and sampled off New Caledonia. We compared several evolutionary scenarios representing both structured (meta-population) and unstructured models and then inferred the Ne variation through time. By performing extensive coalescent simulations, we provided a general framework relating the underlying population structure and the observed Ne dynamics. On this basis, we concluded that the recent decline observed in three out of the four considered species when assuming unstructured demographic models can be explained by the presence of population structure. Furthermore, we also demonstrated the limits of the inferences based on the sole site frequency spectrum and warn that statistics based on linkage disequilibrium will be needed to exclude recent demographic events affecting meta-populations.

scholarly journals Computation is concentrated in rich clubs of local cortical networks

2019 ◽  
Vol 3 (2) ◽  
pp. 384-404 ◽  
Author(s):  
Samantha P. Faber ◽  
Nicholas M. Timme ◽  
John M. Beggs ◽  
Ehren L. Newman
Keyword(s):  
Neural Circuits ◽  
Effective Connectivity ◽  
Neural Computation ◽  
Information Propagation ◽  
Cortical Circuits ◽  
Amount Of Information ◽  
Rich Club ◽  
The Rich ◽  
The Relationship ◽  
Do So

To understand how neural circuits process information, it is essential to identify the relationship between computation and circuit organization. Rich clubs, highly interconnected sets of neurons, are known to propagate a disproportionate amount of information within cortical circuits. Here, we test the hypothesis that rich clubs also perform a disproportionate amount of computation. To do so, we recorded the spiking activity of on average ∼300 well-isolated individual neurons from organotypic cortical cultures. We then constructed weighted, directed networks reflecting the effective connectivity between the neurons. For each neuron, we quantified the amount of computation it performed based on its inputs. We found that rich-club neurons compute ∼160% more information than neurons outside of the rich club. The amount of computation performed in the rich club was proportional to the amount of information propagation by the same neurons. This suggests that in these circuits, information propagation drives computation. In total, our findings indicate that rich-club organization in effective cortical circuits supports not only information propagation but also neural computation.

scholarly journals Conservation assessment and action on Lotus sanguineus (Fabaceae), a critically endangered endemic species to Turkey

Hacquetia ◽  
2020 ◽  
Vol 19 (2) ◽  
pp. 307-315
Author(s):  
Ümit Subaşı ◽  
Fatoş Şekerciler ◽  
Mecit Vural
Keyword(s):  
Endemic Species ◽  
Conservation Status ◽  
In Situ Conservation ◽  
Field Studies ◽  
Critically Endangered ◽  
Ex Situ ◽  
Conservation Strategies ◽  
Conservation Priorities ◽  
Conservation Assessment ◽  
Area Of Occupancy

AbstractLotus sanguineus is one of the endemic taxa from Mediterranean Region of Turkey. It has hitherto been known from type locality and was assessed under VU and EN categories despite the lack of information on the population size, number of location and habitat quality. This study aims to determine the global conservation status and conservation strategies of the narrow endemic species. We collected all available data and evaluated them with the field studies. We reported the sizes of populations, altitude, coordinates, habitat types and the threats it faces for each locality. GeoCAT analyses at global levels indicate the extent of occurrence 19.965 km2 and area of occupancy 9 km2 and there could be an inferred decline due to habitat loss and fragmentation of the original population, suggesting this species might be classified as Critically Endangered, based on criterium B1ab (i, ii, iii) + 2ab (i, ii, iii) in the Red List categorization. Conservation priorities include life history and ecology studies, in-situ conservation, population monitoring and ex-situ conservation to prevent the destruction of the existing gene pool.

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