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NIKOLOV and STEFFEN OPPEL Diet is not related to productivity but to territory occupancy in a declining population of Egyptian Vultures Neophron percnopterus. Bird Conservation International, Available on CJO 2015... more
NIKOLOV and STEFFEN OPPEL Diet is not related to productivity but to territory occupancy in a declining population of Egyptian Vultures Neophron percnopterus. Bird Conservation International, Available on CJO 2015 doi:10.1017/S0959270915000155
Machine learning (ML) has been established and used in science-based applications since the 1970s. The advent and maturation of mathematical algorithms and concepts like Neural Networks, Entropy, Classification and Regression Trees... more
Machine learning (ML) has been established and used in science-based applications since the 1970s. The advent and maturation of mathematical algorithms and concepts like Neural Networks, Entropy, Classification and Regression Trees (CARTs), as well as the enhancement of computational power on personal computers worldwide have allowed for the development of many new applications and good approaches to analyzing highly complex systems and their data. Improvements to classical ML techniques, such as boosting, bagging and ensembles have been developed and combined with ML algorithms to yield powerful new tools for both data exploration and analysis (e.g. classification and prediction). Together with the increasing availability of online datasets (public and private), these tools have formed a new ‘science-culture’ that has yet to be fully embraced by the broader scientific community. ML can be used extremely well for data mining and classification, as well as to draw generalizable inference from powerful predictions (Breiman L, Stat Sci 16:199–231 (2001a); Breiman L, Mach Learn J 45:5–32 (2001b)). Thus, it offers a new scientific platform that can help overcome many of the earlier limitations associated with sparse field data, statistical model-fitting, p-values, parsimony (e.g., AIC), Bayesian and post-hoc studies. In contrast to conventional, statistical model-based data analysis, ML usually is non-parametric, so it does not require a priori assumptions about the structure and complexity of a model, nor is it based on just single linear algorithms. This eliminates potential biases and constraints being built into models that result from these assumptions and traditional singular algorithms. In contrast, ML techniques are classification tools of choice and convenience. They can decipher relevant relationships (‘extract the signal’) directly from virtually any data (e.g. messy, ‘gappy’, very large or rather small). Thus, ML can be seen as a new science philosophy with a newly available statistical approach that allows for faster, alternative and more encompassing results that more adequately generalize and reflect the very complex structure of ecological systems. Because ML is not only flexible but efficient, it is an ideal tool for application in the science-based wildlife and conservation management arenas as well as ecology, where decisions need to be robust but time-critical. Here we review some of the advantages and assumed application pitfalls of several key ML algorithms with published examples from the wildlife ecology and biodiversity disciplines using ‘location only’ (presence) data. We then provide a simulation case study to illustrate our key points, and evaluate how ML has the potential to change the way we use information to manage wildlife in times of a rapidly changing global environment and its ongoing crisis.
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cfforts co opcimize foraging eicher by minimizing encrgy loss chrough passive move menc or by maximizing energecic gain chrough foraging. Here, we assess whecher signals of eicher of chese scracegies are dececcable in the timing of... more
cfforts co opcimize foraging eicher by minimizing encrgy loss chrough passive move menc or by maximizing energecic gain chrough foraging. Here, we assess whecher signals of eicher of chese scracegies are dececcable in the timing of activiry of daily, local movements by birds. We compare the similarities of timing of movement activiry among species using six temporal variables: starr of activiry relative co sunrise, end of activiry relative eo sunsec, relacive speed at midday, number of movemenc boucs, bouc duracion and proporcion of accive daytime hours. We cesc for ehe influence of flighc mode and foraging habirat on the timing of movement activity across avian guilds. We used 64 570 days of GPS movement data collected becween 2002 and 2019 for local (non-migracory) movements of99 I birds from 49 species, represencing 14 orders. Oissimilariry among daily activiry paccerns was besc explained by flighc mode. Terrescrial soaring birds began acciviry later and scopped activiry earlier ...
Research Interests: Biology, Ecology, Avian Biology, Biological Sciences, Foraging, and 4 moreHabitat, Nocturnal, Sunset, and pelagic zone
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Relatively little has been reported about the seabirds of Gough Island, central South Atlantic Ocean, from autumn and winter. We report ad hoc observations on the abundance, phenology and moult of seabirds at Gough Island from March to... more
Relatively little has been reported about the seabirds of Gough Island, central South Atlantic Ocean, from autumn and winter. We report ad hoc observations on the abundance, phenology and moult of seabirds at Gough Island from March to June 2021, and during the voyages between the island and Cape Town, South Africa. At least 43 species of seabirds were recorded: 1 penguin, 8 albatrosses, 5 southern and 1 northern storm petrel, 22 petrels and shearwaters, 1 gannet, 3 terns and 2 skuas. The results are presented as an annotated species list as well as a daily log of species for the voyages to and from the island. More species were seen per day at sea in June than in March, but fewer individuals were recorded in oceanic waters, mainly due to the large numbers of Great Shearwaters Ardenna gravis in March.
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doi:10.1017/S0959270914000343 Population decline and range contraction of the
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Giant petrels Macronectes spp. are the largest avian predator-scavengers in the Southern Ocean and feed both by direct predation and by scavenging carrion. However, they are not considered to be predators of adult albatrosses. We report... more
Giant petrels Macronectes spp. are the largest avian predator-scavengers in the Southern Ocean and feed both by direct predation and by scavenging carrion. However, they are not considered to be predators of adult albatrosses. We report the first records of Southern Giant Petrels M. giganteus attacking and killing incubating Atlantic Yellow-nosed Albatrosses Thalassarche chlororhynchos on Gough Island. From 2017 to 2019, a total of 87 adult carcasses were found near nests within long-term monitoring areas. In 2019, 16 motion-activated cameras filmed 32 nests between September and January, during incubation up until chicks were no longer guarded by their parents. Camera footage revealed at least six different male Southern Giant Petrels independently attacking 11 incubating Atlantic Yellow-nosed Albatrosses, killing and feeding on 5 of those. We also recorded a Southern Giant Petrel attacking a brooding Atlantic Yellow-nosed Albatross and carrying its chick away. Of these camera-monitored nests breeding success was 18.75%, nest failure was due to parent mortality (n = 6), chick mortality (3) and nest abandonment (17), with giant petrels being confirmed or strongly suspected in at least 14 of 26 cases (54%). We observed these attacks in two out of 11 study areas, but it is uncertain whether this behaviour occurs elsewhere on Gough Island, or whether it is a novel hunting method learnt by a few individuals. However, if this behaviour spreads across albatross colonies, the resulting increase in adult mortality could have a significant impact on this endangered Atlantic Yellow-nosed Albatross population.
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Andrew L. Mack & Steffen Oppel 61 Bull. В. О. С. 2006 126(1) Nidification of Dwarf Whistler Pachycare flavogriseum^ a little-known New Guinea endemic by Andrew L. Mack & Steffen Oppel Received 21 April 2005 The Dwarf... more
Andrew L. Mack & Steffen Oppel 61 Bull. В. О. С. 2006 126(1) Nidification of Dwarf Whistler Pachycare flavogriseum^ a little-known New Guinea endemic by Andrew L. Mack & Steffen Oppel Received 21 April 2005 The Dwarf Whistler or Goldenface Pachycare flavogriseum is a distinctive ...
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SummaryChanges in food availability that lead to lower reproductive output or lower survival probability are important drivers of the widespread declines in vulture populations. Permanent feeding stations for scavengers, such as vulture... more
SummaryChanges in food availability that lead to lower reproductive output or lower survival probability are important drivers of the widespread declines in vulture populations. Permanent feeding stations for scavengers, such as vulture restaurants or rubbish dumps, may have both positive and negative effects on reproductive parameters. Here we examine the effects of the closure of a large communal rubbish dump on breeding success and fledging rate of a dense population of the ’Endangered’ Egyptian Vulture Neophron percnopterus in central Turkey to assess whether the closure may have affected the population. We monitored territories from 2011 to 2016, and tested whether the closure of the rubbish dump in early 2015 coincided with changes in reproductive parameters while accounting for confounding variables such as weather and the availability of other predictable foraging opportunities. We found an average productivity of 0.78 fledglings per territorial pair before the dump closed a...
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Research Interests: Geography, Law, Political Science, Foraging, Tracking, and 12 moreTelemetry, Bycatch, Ciencias Biológicas, Value of Information, Seabird, Marine Policy, Marine Protected Area, Conservación De La Biodiversidad, Elsevier, Enseñanza - Aprendizaje Ciencias Naturales Y Exactas, ENVIRONMENTAL SCIENCE AND MANAGEMENT, and Spatial Aggregation
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Research Interests: Geography and Ornithology
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SummaryA prominent threat to European vultures has been sanitary regulations that banned the disposal of livestock carcasses. Changes in food abundance following these regulations have been associated with changes in vulture behaviour and... more
SummaryA prominent threat to European vultures has been sanitary regulations that banned the disposal of livestock carcasses. Changes in food abundance following these regulations have been associated with changes in vulture behaviour and demographic parameters, but to what extent diet changes are responsible for population declines is poorly understood. The Egyptian Vulture Neophron percnopterus is the smallest and most threatened European vulture species and has an opportunistic and diverse diet. In Eastern Europe, the Egyptian Vulture population is declining more rapidly than elsewhere but there is little information on diet composition and the relationship between diet and demographic parameters to inform conservation management. We examined whether Egyptian Vulture population declines in Bulgaria and Greece may have been associated with diet changes that affected breeding productivity by monitoring breeding success and collecting diet remains from 143 Egyptian Vulture breeding ...
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Research Interests: Demography, Ornithology, Reproduction, Tropical Ecology, Caribbean Studies, and 15 moreEcology, Invasive Species, Wildlife Conservation, Endangered Species, Seasonality, Parental care, Predation, Clutch Size, Introduced species, Wild animals, Predators, Oriole, Breeding Biology, Conservation Management, and Condor
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Petrels (Procellariidae) are a highly diverse family of seabirds, many of which are globally threatened due to the impact of invasive species on breeding populations. While predation by invasive cats and rats has led to the extinction of... more
Petrels (Procellariidae) are a highly diverse family of seabirds, many of which are globally threatened due to the impact of invasive species on breeding populations. While predation by invasive cats and rats has led to the extinction of petrel populations, the impact of invasive house mice Mus musculus is slower and less well documented. However, mice impact small burrow-nesting species such as MacGillivray’s prion Pachyptila macgillivrayi, a species classified as endangered because it has been extirpated on islands in the Indian Ocean by introduced rodents. We use historic abundance data and demographic monitoring data from 2014 to 2020 to predict the population trajectory of MacGillivray’s prion on Gough Island with and without a mouse eradication using a stochastic integrated population model. Given very low annual breeding success (0.01 fledglings per breeding pair in ‘poor’ years (83%) or 0.38 in ‘good’ years (17%), n = 320 nests over 6 years) mainly due to mouse predation, ou...
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Summary The United Nations Sustainable Development Goals aim to improve livelihoods and maintain functioning ecosystems, and include the provision of electricity and the prevention of desertification. We show that the pursuit of those two... more
Summary The United Nations Sustainable Development Goals aim to improve livelihoods and maintain functioning ecosystems, and include the provision of electricity and the prevention of desertification. We show that the pursuit of those two goals can lead to developments that put critical ecosystem functions at risk. Vultures are scavengers that provide sanitary ecosystem services, but their populations across Africa are declining due to poisoning, electrocution, and collision with power infrastructure. The extent to which the pursuit of sustainable development threatens vultures in Africa is unclear. We surveyed 227 km of powerlines in Ethiopia, which revealed bird mortality (0.15 vulture carcasses / km) at power infrastructure constructed under a National Electrification Programme to provide universal electricity access by 2025. We also interviewed 190 local pastoralists in 10 areas about livelihood challenges, which revealed that the bush Prosopis juliflora, which was originally in...
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Colonially breeding birds and mammals form some of the largest gatherings of apex predators in the natural world and have provided model systems for studying mechanisms of population regulation in animals. According to one influential... more
Colonially breeding birds and mammals form some of the largest gatherings of apex predators in the natural world and have provided model systems for studying mechanisms of population regulation in animals. According to one influential hypothesis, intense competition for food among large numbers of spatially constrained foragers should result in a zone of prey depletion surrounding such colonies, ultimately limiting their size. However, while indirect and theoretical support for this phenomenon, known as “Ashmole’s halo,” has steadily accumulated, direct evidence remains exceptionally scarce. Using a combination of vessel-based surveys and Global Positioning System tracking, we show that pelagic seabirds breeding at the tropical island that first inspired Ashmole’s hypothesis do indeed deplete their primary prey species (flying fish; Exocoetidae spp.) over a considerable area, with reduced prey density detectable >150 km from the colony. The observed prey gradient was mirrored by ...
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Migratory marine species cross political borders and enter the high seas, where the lack of an effective global management framework for biodiversity leaves them vulnerable to threats. Here, we combine 10,108 tracks from 5775 individual... more
Migratory marine species cross political borders and enter the high seas, where the lack of an effective global management framework for biodiversity leaves them vulnerable to threats. Here, we combine 10,108 tracks from 5775 individual birds at 87 sites with data on breeding population sizes to estimate the relative year-round importance of national jurisdictions and high seas areas for 39 species of albatrosses and large petrels. Populations from every country made extensive use of the high seas, indicating the stake each country has in the management of biodiversity in international waters. We quantified the links among national populations of these threatened seabirds and the regional fisheries management organizations (RFMOs) which regulate fishing in the high seas. This work makes explicit the relative responsibilities that each country and RFMO has for the management of shared biodiversity, providing invaluable information for the conservation and management of migratory spec...