Suchergebnisse

Time to strengthen and enforce the north american migratory bird treaty act
The number of migratory bird populations is declining; Keith Hobson, professor and research scientist at Environment and Climate Change Canada and Western University, outlines the importance of updating conventions to protect these vulnerable species. One of the great current challenges of effective wildlife conservation globally involves the protection of migratory organisms that cross international boundaries during their annual cycle. The challenge is obvious when considering the myriad of obstacles involved with international agreements and requirements for on-the-ground compliance, especially when considering different languages, cultures and political systems. Nonetheless, such international cooperation is needed now more than ever as migratory animals have been found to be declining at greater rates than their non-migratory counterparts. That is especially the case for migratory birds. Not surprisingly, apart from regulations involving trade in wildlife or wildlife parts, such as the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), few success stories exist.

Cuba's first motus tower for tracking migrant land birds
Keith Hobson, Professor and Research Scientist at Environment and Climate Change Canada and Western University, discusses updates in the expansion of tracking migratory birds in Central and South America, and the Caribbean. The conservation of migratory birds requires basic knowledge of connectivity between population-specific breeding, wintering, and stopover sites. This recognition has encouraged several government and NGO initiatives since many migratory species cross international borders during their annual travels. While the task is immensely difficult, an array of new tools is now available to track even small birds (~10g) using both intrinsic (e.g. stable isotope or genetic markers) and extrinsic (e.g. attached electronic devices) methods.

Isotopic applications assit in forensic tracking of illegally traded wildlife parts
Keith A. Hobson, a Research Scientist and Professor at Environment and Climate Change Canada, discusses the use of stable isotopes to trace the origins of animal parts in order to mitigate the illegal wildlife trade. As of 2022, the illegal global trade in tissues of (CITES and non-CITES listed) wildlife has been estimated to be on the order of $220 billion,(1) placing this practice among the top four of all global criminal enterprises. As ecosystems and the wild animals and plants they harbor come under increasing pressure from human developments, such trade threatens many species with decimation and ultimate extinction. Governments continue to struggle with the extent of this phenomenon and generally have few tools available to counter this growing trend. However, once seized, wildlife parts can be examined forensically to help ascertain provenance, and such tools can contribute in a small way to counter such criminal activity.

Stored fuel's importance for migrating monarch butterflies: Implications for conserving all migrant animals
In his latest research, Keith A. Hobson, Research Scientist and Professor at Western University, explores why stored fuel is critical to migrating animals, such as monarch butterflies. Conserving migratory animals in a rapidly changing world requires we quickly and efficiently determine the most critical or vulnerable points in their annual cycles that typically involve numerous locations spread over hundreds to thousands of kilometers. Although we know migration routes or connections between breeding and wintering regions for many species of concern, how animals fuel their migration along migratory paths and how their nutritional needs are affected by various factors generally remains unknown. In times of current and predicted climate change, the added burdens of weather extremes add to the many threats facing migrants. So it is ever more urgent to ensure that our conservation efforts and funds are directed at the most critical locations temporally and spatially.

Tracking animal migration with stable isotopes
Keith A. Hobson from Western University and Environment and Climate Change Canada, walks us through tracking animal migration with stable isotopes, starting with some background information. Animal migration is one of the most iconic of all natural phenomena and humans have marvelled at animals' ability to navigate over vast distances often under arduous conditions. Periodic to-and-fro migration is the most familiar form, and birds have clearly captured our imagination on that front with their conspicuous annual movements and arrivals between continents. However, how animals successfully move in this way is still not fully appreciated, and a full understanding will ultimately involve expertise from diverse disciplines.

Marine top and meso predators like seabirds are limited by the need to breed on land but forage on limited or patchily distributed resources at sea. Constraints imposed by such central-place foraging behavior change during breeding or even disappear outside the breeding period when there is no immediate pressure to return to a central place. However, central place foraging is usually factored as an unchanging condition in life history studies. Here we used little penguin Eudyptula minor, a resident bird with one of the smallest foraging range among seabirds, to examine the different degree of pressure/constraints of being a central-place forager. We combined data on isotopic composition (δ13C and δ15N), conventional stomach contents and body mass of little penguins breeding at Phillip Island, Australia over 9 years (2003–2011). We explored relationships between diet and body mass in each stage of the breeding season (pre-laying, incubation, guard, and post-guard) in years of "high" and "low" reproductive success. Values of δ13C and δ15N as well as isotopic niche width had similar patterns among years, with less variability later in the season when little penguins shorten their foraging range at the expected peak of their central-place foraging limitation. Body mass peaked before laying and hatching in preparation for the energetically demanding periods of egg production and chick provisioning. An increase of anchovy and barracouta in the diet, two major prey for little penguins, occurred at the critical stage of chick rearing. These intra-annual trends could be a response to imposed foraging constraints as reproduction progresses, while inter-annual trends could reflect their ability to match or mismatch the high energy demanding chick rearing period with the peak in availability of high-quality prey such as anchovy. Our findings underline the key advantages of using a stable isotope approach combined with conventional dietary reconstruction to reveal an otherwise intractable ecological issue of different constrains of being a central-place forager, such as the little penguin, which could be applied to other marine species. ; We are thankful for several grants received to support this collaborative research: Penguin Foundation, Junta Andalucía, European Union Research Fund and Ministerio de Educación y Ciencia de España. ; Peer reviewed ; Peer Reviewed

In France, illegal hunting of the endangered ortolan bunting Emberiza hortulana has been defended for the sake of tradition and gastronomy. Hunters argued that ortolan buntings trapped in southwest France originate from large and stable populations across the whole of Europe. Yet, the European Commission referred France to the Court of Justice of the European Union (EU) in December 2016 for infringements to legislation (IP/16/4213). To better assess the impact of hunting in France, we combined Pan-European data from archival light loggers, stable isotopes, and genetics to determine the migration strategy of the species across continents. Ortolan buntings migrating through France come from northern and western populations, which are small, fragmented and declining. Population viability modeling further revealed that harvesting in southwest France is far from sustainable and increases extinction risk. These results provide the sufficient scientific evidence for justifying the ban on ortolan harvesting in France.

In France, illegal hunting of the endangered ortolan bunting Emberiza hortulana has been defended for the sake of tradition and gastronomy. Hunters argued that ortolan buntings trapped in southwest France originate from large and stable populations across the whole of Europe. Yet, the European Commission referred France to the Court of Justice of the European Union (EU) in December 2016 for infringements to legislation (IP/16/4213). To better assess the impact of hunting in France, we combined Pan-European data from archival light loggers, stable isotopes, and genetics to determine the migration strategy of the species across continents. Ortolan buntings migrating through France come from northern and western populations, which are small, fragmented and declining. Population viability modeling further revealed that harvesting in southwest France is far from sustainable and increases extinction risk. These results provide the sufficient scientific evidence for justifying the ban on ortolan harvesting in France.

In France, illegal hunting of the endangered ortolan bunting Emberiza hortulana has been defended for the sake of tradition and gastronomy. Hunters argued that ortolan buntings trapped in southwest France originate from large and stable populations across the whole of Europe. Yet, the European Commission referred France to the Court of Justice of the European Union (EU) in December 2016 for infringements to legislation (IP/16/4213). To better assess the impact of hunting in France, we combined Pan-European data from archival light loggers, stable isotopes, and genetics to determine the migration strategy of the species across continents. Ortolan buntings migrating through France come from northern and western populations, which are small, fragmented and declining. Population viability modeling further revealed that harvesting in southwest France is far from sustainable and increases extinction risk. These results provide the sufficient scientific evidence for justifying the ban on ortolan harvesting in France.

In France, illegal hunting of the endangered ortolan bunting Emberiza hortulana has been defended for the sake of tradition and gastronomy. Hunters argued that ortolan buntings trapped in southwest France originate from large and stable populations across the whole of Europe. Yet, the European Commission referred France to the Court of Justice of the European Union (EU) in December 2016 for infringements to legislation (IP/16/4213). To better assess the impact of hunting in France, we combined Pan-European data from archival light loggers, stable isotopes, and genetics to determine the migration strategy of the species across continents. Ortolan buntings migrating through France come from northern and western populations, which are small, fragmented and declining. Population viability modeling further revealed that harvesting in southwest France is far from sustainable and increases extinction risk. These results provide the sufficient scientific evidence for justifying the ban on ortolan harvesting in France.