300 research outputs found
Forecasting ocean warming impacts on seabird demography: a case study on the European storm petrel
Bottom-up climatic forcing has been shown to be influential for a variety of marine
taxa, but evidence on seabird populations is scarce. Seasonal variation in environmental conditions
can have an indirect effect on subsequent reproduction, which, given the longevity and
single-brooding of seabirds, may affect population dynamics. Our study focuses on linking the
effect of oceanographic conditions (from 1991 to 2013) to the fecundity and consequently pop -
ulation growth rate of the Mediterranean subspecies of the European storm petrel Hydrobates
pelagicus melitensis. In this study, we examined 23 yr of > 5400 captureâmarkârecaptures (CMR)
and modelled the probability of skipping reproduction as a function of oceanographic variables
using CMR models. We demonstrate that a decrease in sea surface temperature in the pre-breeding
period negatively influences skipping propensity, and therefore hypothesize that this behaviour
would have significant influence on population abundance over time. For this reason, we analysed
population growth as a function of skipping probability as affected by oceanographic
conditions. We used stochastic demographic models to forecast the fate of the population, and
evaluated contrasted environmental condition scenarios. As a result, we found that a decrease in
frequency of cold winter events would probably reduce skipping propensity, with a positive effect
on the population as a whole
Linking food web functioning and habitat diversity for an ecosystem based management: A Mediterranean lagoon case-study
We propose a modelling approach relating the functioning of a transitional ecosystem with the spatial extension of its habitats. A test case is presented for the lagoon of Venice, discussing the results in the context of the application of current EU directives. The effects on food web functioning due to changes related to manageable and unmanageable drivers were investigated. The modelling procedure involved the use of steady-state food web models and network analysis, respectively applied to estimate the fluxes of energy associated with trophic interactions, and to compute indices of food web functioning. On the long term (hundred years) temporal scale, the model indicated that the expected loss of salt marshes will produce further changes at the system level, with a lagoon showing a decrease in the energy processing efficiency. On the short term scale, simulation results indicated that fishery management accompanied by seagrass restoration measures would produce a slight transition towards a more healthy system, with higher energy cycling, and maintaining a good balance between processing efficiency and resilience. Scenarios presented suggest that the effectiveness of short term management strategies can be better evaluated when contextualized in the long term trends of evolution of a system. We also remark the need for further studying the relationship between habitat diversity and indicators of food web functioning
Diet and diving behaviour of European Storm Petrels Hydrobates pelagicus in the Mediterranean (ssp. melitensis).
Unlike Atlantic populations, which feed on krill, Mediterranean populations feed mainly on pelagic fish Gymnammodites cicerellus. European Storm Petrels in the Mediterranean exploit pelagic fish which are taken by
diving. This contrasts with the Atlantic populations which feed mainly on krill. Mediterranean birds also feed on Opossum Shrimps Mysidacea during short foraging trips made at night just outside the colony. Differences in diet between long and short foraging trips may be because adults have to forage for both themselves and their chicks
Old and novel methods for estimating Feral Pigeons (Columba livia f. domestica) population size: a reply to Amoruso et al. (2013)
In a recent paper Amoruso et al. (2013) proposed a novel method for estimating
population size of Feral Pigeons, the Superimposed Urban Strata (SUS) method. In our reply
we firstly comment on the lack of a complete review of the available literature. Secondly we
point out that the SUS method does not account for birds detection probability and thus it is
just a simple index of abundance as many others proposed in recent years. Thirdly, we
question the approach used by the authors to evaluate the reliability of their method. To
conclude, we believe that the SUS method is not truly innovative and that further
investigations are needed before considering it as a reliable way for estimating Feral Pigeons
populations size
Historical SST warming events in the Northeastern Pacific: How unique is the Warm Blob?
During 2013-2015 a patch of warm water called Warm Blob appeared in the northeastern Pacific, producing several effects at biological and physical level. This event appears to be unique, however, evidence was encountered for another three events similar to the recent Warm Blob event during the period from 1854 to 2017 through analyzing the historical anomalies of the SST anomalies in the Pacific Ocean. Each event showed the same distinctive Warm Blob spatial pattern âfirstly, a patch of warm water develops in the northern Pacific south of Alaska, and gradually spreads southward along the coast reaching up to Baja California Peninsulaâ. During the 2013-2015 event, this warm water patch raised the seawater temperature anomalies above 0.5 °C, with a maximum of 4 °C. The other past events obtained in the time series analysis occurred in 1874, 1936 and 1962 and lasted around 18-24 months each. Each warming event is described, showing that the most intense was the 2013-15, followed by the 1935-36. The results suggest a periodicity of occurrence of 25 to 60 years that can also be traced on the biology of the region. These findings propose that such warmings are part of the climatic variability in the northeastern Pacific and should be studied with more detail to determine its cause.
Wildlife strike risk assessment in several Italian airports: lessons from BRI and a new methodology implementation
The presence of wildlife in airport areas poses substantial hazards to aviation. Wildlife aircraft collisions (hereafter wildlife strikes) cause losses in terms of human lives and direct monetary losses for the aviation industry. In recent years, wildlife strikes have increased in parallel with air traffic increase and species habituation to anthropic areas. In this paper, we used an ecological approach to wildlife strike risk assessment to eight Italian international airports. The main achievement is a site-specific analysis that avoids flattening wildlife strike events on a large scale while maintaining comparable airport risk assessments. This second version of the Birdstrike Risk Index (BRI2) is a sensitive tool that provides different time scale results allowing appropriate management planning. The methodology applied has been developed in accordance with the Italian Civil Aviation Authority, which recognizes it as a national standard implemented in the advisory circular ENAC APT-01B
A novel combination of methods identifies priority conservation areas for an endemic California Current seabird
There are growing pressures on marine biodiversity. Seabirds in particular are one the most-threatened groups. The black-vented shearwater (Puffinus opisthomelas) is endemic to Mexican islands and the only shearwater living its entire life cycle in the California Current System, one of the most productive large marine ecosystems in the world. Marine Protected Areas (MPAs) in this region, however, were designed without consideration of accurate data on seabird distributions.
Here, 57 black-vented shearwaters were GPS-tracked from their main breeding colony (95% of the global population) over four seasons (2016â2019) to estimate their at-sea distribution. Two methods were applied to identify priority conservation areas: the approach developed by BirdLife International to identify marine Important Bird and Biodiversity Areas and a method using expectation-maximization binary clustering to identify core foraging areas.
One potential marine Important Bird and Biodiversity Area close to the breeding colony and five core foraging areas were identified. These priority conservation areas were largely beyond the bounds of the current MPA network in the region.
Our results detail opportunities for improving the implementation of conservation and management measures in the California Current System region with respect to seabirds. The approach of combining site identification methods can be applied to other seabird species for which high-resolution tracking data are available and can help guide conservation action plans and MPA design.info:eu-repo/semantics/submittedVersio
use of captive bred passerines to monitor human disturbance using corticosterone metabolites
Given that human-wildlife conflicts are an everyday issue, we propose the use of captive bred birds to determine the effects that environmental acoustic disturbance may have on small passerines. We used greenfinches and located them at three rural and one urban site and collected faeces to measure corticosterone metabolites using enzyme immunoassays. We found that birds at the urban site excreted higher amounts of corticosterone metabolites than those at the natural sites, but that some natural sites also had high levels of corticosterone when noise levels were high. We conclude that captive bred individuals can be used to monitor sites where there may be possible effects of disturbance on wild individuals
Climate driven life histories: the case of the Mediterranean Storm petrel
Seabirds are affected by changes in the marine ecosystem. The influence of climatic factors on marine food webs can be reflected in long-term seabird population changes. We modelled the survival and recruitment of the Mediterranean storm petrel (Hydrobates pelagicus melitensis) using a 21-year mark-recapture dataset involving almost 5000 birds. We demonstrated a strong influence of prebreeding climatic conditions on recruitment age and of rainfall and breeding period
conditions on juvenile survival. The results suggest that the juvenile survival rate of the Mediterranean subspecies may not be negatively affected by the predicted features of climate change, i.e., warmer summers and lower rainfall. Based on
considerations of winter conditions in different parts of the Mediterranean, we were able to draw inferences about the wintering areas of the species for the first time
Essential ocean variables for global sustained observations of biodiversity and ecosystem changes
International audience; Sustained observations of marine biodiversity and ecosystems focused on specific conservation and management problems are needed around the world to effectively mitigate or manage changes resulting from anthropogenic pressures. These observations, while complex and expensive, are required by the international scientific, governance and policy communities to provide baselines against which the effects of human pressures and climate change may be measured and reported, and resources allocated to implement solutions. To identify biological and ecological essential ocean variables (EOVs) for implementation within a global ocean observing system that is relevant for science, informs society, and technologically feasible, we used a driver-pressure-state-impact-response (DPSIR) model. We (1) examined relevant international agreements to identify societal drivers and pressures on marine resources and ecosystems, (2) evaluated the temporal and spatial scales of variables measured by 100+ observing programs, and (3) analysed the impact and scalability of these variables and how they contribute to address societal and scientific issues. EOVs were related to the status of ecosystem components (phytoplankton and zoo-plankton biomass and diversity, and abundance and distribution of fish, marine turtles, birds and mammals), and to the extent and health of ecosystems (cover and composition of hard coral, seagrass, mangrove and macroalgal canopy). Benthic invertebrate abundance and distribution and microbe diversity and biomass were identified as emerging EOVs to be developed based on emerging requirements and new technologies. The temporal scale at which any shifts in biological systems will be detected will vary across the EOVs, the properties being monitored and the length of the existing time-series. Global implementation to deliver useful products will require collaboration of the scientific and policy sectors and a significant commitment to improve human and infrastructure capacity across the globe, including the development of new, more automated observing technologies, and encouraging the application of international standards and best practices
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