Conservation Of Migratory Species Research Articles

Estimating migratory connectivity of birds when re-encounter probabilities are heterogeneous.

Understanding the biology and conducting effective conservation of migratory species requires an understanding of migratory connectivity – the geographic linkages of populations between stages of the annual cycle. Unfortunately, for most species, we are lacking such information. The North American Bird Banding Laboratory (BBL) houses an extensive database of marking, recaptures and recoveries, and such data could provide migratory connectivity information for many species. To date, however, few species have been analyzed for migratory connectivity largely because heterogeneous re-encounter probabilities make interpretation problematic. We accounted for regional variation in re-encounter probabilities by borrowing information across species and by using effort covariates on recapture and recovery probabilities in a multistate capture–recapture and recovery model. The effort covariates were derived from recaptures and recoveries of species within the same regions. We estimated the migratory connectivity for three tern species breeding in North America and over-wintering in the tropics, common (Sterna hirundo), roseate (Sterna dougallii), and Caspian terns (Hydroprogne caspia). For western breeding terns, model-derived estimates of migratory connectivity differed considerably from those derived directly from the proportions of re-encounters. Conversely, for eastern breeding terns, estimates were merely refined by the inclusion of re-encounter probabilities. In general, eastern breeding terns were strongly connected to eastern South America, and western breeding terns were strongly linked to the more western parts of the nonbreeding range under both models. Through simulation, we found this approach is likely useful for many species in the BBL database, although precision improved with higher re-encounter probabilities and stronger migratory connectivity. We describe an approach to deal with the inherent biases in BBL banding and re-encounter data to demonstrate that this large dataset is a valuable source of information about the migratory connectivity of the birds of North America.

Conservation of migratory Magellanic penguins requires marine zoning

Conservation of migratory species requires an understanding of their migration path and pattern. We used band returns and satellite tracking to characterize the seasonal migration of Magellanic penguins breeding in southern Argentina, with the purpose of identifying an effective conservation approach for this species. Band returns show these penguins migrate annually to the coastal waters of northern Argentina, Uruguay, and southern Brazil, an average one-way distance of approximately 2000km, and a modal distance of 2300–2400km. Satellite data indicate that the penguins follow a migration corridor within 250km of shore. Mean migration distance varied among years. Juveniles migrated farther on average than older birds, although migration distance of different age classes overlapped substantially. Mortality rates during migration were higher among younger birds, and juvenile mortality rate during migration was inversely correlated with cohort survival, indicating that mortality during migration is an important determinant of population recruitment. A minimum of 13% of the migration-period mortality we recorded resulted from fisheries bycatch and oil pollution. Because of the penguin’s mode of travel (swimming at or near the surface), the large spatial extent of its migration, and the intensity of human use of the area, effective conservation through conventional coastal marine reserves is unlikely. Marine zoning is an alternative that could provide the spatial scale and flexibility necessary to accommodate both penguin migration and human activities. As the waters traversed by Magellanic penguins are among the most threatened in Latin America, zoning for protection of this wide-ranging and charismatic species can also protect regional biodiversity.

Optimism and Challenge for Science‐Based Conservation of Migratory Species in and out of U.S. National Parks

Public agencies sometimes seek outside guidance when capacity to achieve their mission is limited. Through a cooperative agreement and collaborations with the U.S. National Park Service (NPS), we developed recommendations for a conservation program for migratory species. Although NPS manages ∼ 36 million hectares of land and water in 401 units, there is no centralized program to conserve wild animals reliant on NPS units that also migrate hundreds to thousands of kilometers beyond parks. Migrations are imperiled by habitat destruction, unsustainable harvest, climate change, and other impediments. A successful program to counter these challenges requires public support, national and international outreach, and flourishing migrant populations. We recommended two initial steps. First, in the short term, launch or build on a suite of projects for high-profile migratory species that can serve as proof to demonstrate the centrality of NPS units to conservation at different scales. Second, over the longer term, build new capacity to conserve migratory species. Capacity building will entail increasing the limited knowledge among park staff about how and where species or populations migrate, conditions that enable migration, and identifying species' needs and resolving them both within and beyond parks. Building capacity will also require ensuring that park superintendents and staff at all levels support conservation beyond statutory borders. Until additional diverse stakeholders and a broader American public realize what can be lost and do more to protect it and engage more with land management agencies to implement actions that facilitate conservation, long distance migrations are increasingly likely to become phenomena of the past.

Wildebeest (<i>Connochaetes taurinus</i>) Population Densities and Distribution in Dry and Wet Season in the Kilimanjaro Landscape

The conservation of migratory wildlife species in the savannah habitat can be a challenge because of frequent and prolonged drought and their requirements for a large area. We investigated the performance of the wildebeest (Connochaetes taurinus) population in the 25,624 km2 Kilimanjaro landscape of Kenya and Tanzania, which comprises Amboseli-West Kilimanjaro-Magadi-Natron after 2009 drought. We used total aerial counts to determine the spatial distribution and numbers of wildebeests during wet and dry season in 2010 and 2013. Global Positioning System and digital voice recorders were used to count wildebeests along established transects within blocks. There was an increase in the wildebeest population by 103% during the wet season and 14% during the dry season between 2010 and 2013. The seasonal variation in density occurred between the four counting blocks with Natron and Magadi areas recording the highest densities. Generally, the increase in population could be attributed to the recovery of the population after the 2009 drought. The current cross border collaboration between Kenya and Tanzania in aerial surveys is an important step in the conservation of this migratory species in the landscape. This study demonstrates that detailed knowledge of density and spatial distribution of migratory species is required to plan effective conservation action.

Annual migratory patterns of Long-billed Curlews in the American West

Effective conservation of migratory species requires comprehensive knowledge of annual movement patterns. Such information is sparse for the Long-billed Curlew (Numenius americanus), a North American endemic shorebird of conservation concern. To test hypotheses about individual and area differences in migratory patterns across western North America, we tagged 29 curlews with satellite transmitters at breeding sites in Oregon, Nevada, and Montana. Transmissions from 28 birds for up to 4 years demonstrated that all wintered within the species’ known winter range, including 9 from Oregon tracked to agricultural areas of California’s Central Valley; 5 from Nevada tracked to the Central Valley, northern Gulf of California, or west coast of Baja California, Mexico; and 14 from Montana that wintered inland, from the Texas Panhandle south to the Mexican Plateau, or near the Gulf of Mexico. Montana breeders migrated east of the Rocky Mountains and traveled more than twice the distance of Oregon and Nevada breeders. Montana birds also stopped more often and longer during most passages. As a group, curlews arrived on their Oregon breeding grounds earlier than in Montana, while males preceded females in Montana and possibly Oregon. No consistent pattern emerged between sexes in departure from breeding areas, although within pairs males departed later than their mates. Individuals exhibited strong fidelity to breeding and wintering sites, and many birds showed a strong propensity for agricultural regions during winter. Our results underscore the importance of studying migration behavior across the breeding range to adequately capture variation in migratory patterns of a species.

C. Convention on the Conservation of Migratory Species of Wild Animals (CMS)

C. Convention on the Conservation of Migratory Species of Wild Animals (CMS)

Inter‐Treaty Cooperation, Biodiversity Conservation and the Trade in Endangered Species

In recent years, concerns have been raised over the ability of multilateral environmental agreements to effectively coordinate their policies and activities on issues of mutual interest. This article examines the current initiatives pursued by the 1973 Convention on International Trade in Endangered Species (CITES) to synergize its activities for the conservation of biodiversity with allied regimes. It examines cooperative policies undertaken alongside the two key biodiversity treaties with which CITES operates most closely – namely the 1992 Convention on Biological Diversity and the 1979 Convention on the Conservation of Migratory Species of Wild Animals. The article outlines broad thematic and species‐specific interactions, suggesting that while there is considerable scope to develop cooperative working practices, a degree of caution is appropriate as to the current level of priority placed upon synergies between these regimes as a solution to operative challenges.

C. Convention on the Conservation of Migratory Species of Wild Animals (CMS)

C. Convention on the Conservation of Migratory Species of Wild Animals (CMS)

Transboundary Wildlife Conservation in A Changing Climate: Adaptation of the Bonn Convention on Migratory Species and Its Daughter Instruments to Climate Change

Species migrating across boundaries represent the classic case for international cooperation in biodiversity conservation. Climate change is adding fresh challenges to such cooperation, on account of the shifting ranges and particular vulnerabilities to climate change of migratory wildlife. In view of the need to help migratory species adapt to climate change with minimal losses, this article performs an in-depth analysis of the present and potential future role in respect of climate adaptation of the main intergovernmental regime for migratory species conservation, the 1979 Bonn Convention on the Conservation of Migratory Species of Wild Animals (CMS) and its various daughter instruments.

Legal and institutional tools to mitigate marine turtle bycatch: Argentina as a case study

This paper explores conservation policy pertinent to three species of marine turtles affected by fisheries, while crossing jurisdictions in their seasonal migrations through the SW Atlantic, particularly the Argentine waters. This case study reviews local legal and institutional frameworks for Argentina and concludes that tools are in place to monitor and mitigate the negative impact of bycatch on the populations. Argentina is signatory of the most relevant international treaties aimed at protecting transboundary species (e.g. Inter-American Convention for the Protection and Conservation of Sea Turtles, Convention on the Conservation of Migratory Species of Wild Animals). Legislation also exists at the federal and provincial levels. Yet, accidental captures continue to occur due to weaknesses in enforcement and the low priority that conservation has in fisheries management decisions. Some urgent practical actions supported by policy are suggested: (a) placement of on-board observers in coastal fishing fleets, (b) application of existing mitigation measures to reduce bycatch, (c) design of a national plan of action for marine turtles in Argentina, and (d) development of a regional plan between Argentina, Brazil and Uruguay. Stakeholder involvement, especially the fishing sector but also the civil society, would be important to energize practical and effective conservation decisions. The example of Argentina is typical for the region and may apply to other countries as well. The conservation community requires investing more in the application of policy, concomitant with perfecting legal tools. ► As transboundary species, marine turtles are exposed to bycatch in several fisheries. ► One tool in marine turtle conservation is policy. ► The legal and institutional framework of Argentina pertinent to bycatch is explored. ► Laws and agencies are in place, yet weaknesses in enforcement hinder conservation. ► Suggestions to advance marine turtle conservation in the region are advanced.

Metapopulation models for seasonally migratory animals

Metapopulation models are widely used to study species that occupy patchily distributed habitat, but are rarely applied to migratory species, because of the difficulty of identifying demographically independent subpopulations. Here, we extend metapopulation theory to describe the directed seasonal movement of migratory populations between two sets of habitat patches, breeding and non-breeding, with potentially different colonization and extinction rates between patch types. By extending the classic metapopulation model, we show that migratory metapopulations will persist if the product of the two colonization rates exceeds the product of extinction rates. Further, we develop a spatially realistic migratory metapopulation model and derive a landscape metric-the migratory metapopulation capacity-that determines persistence. This new extension to metapopulation theory introduces an important tool for the management and conservation of migratory species and may also be applicable to model the dynamics of two host-parasite systems.

Genetic variation and seasonal migratory connectivity in Wilson’s warblers (Wilsonia pusilla): species-level differences in nuclear DNA between western and eastern populations

There is growing interest in understanding patterns of seasonal migratory connectivity between breeding and wintering sites, both because differences in migratory behaviour can be associated with population differentiation and because knowledge of migratory connectivity is essential for understanding the ecology, evolution and conservation of migratory species. We present the first broad survey of geographic variation in the nuclear genome of breeding and wintering Wilson's warblers (Wilsonia pusilla), which have previously served as a research system for the study of whether genetic markers and isotopes can reveal patterns of migratory connectivity. Using 153 samples surveyed at up to 257 variable amplified fragment length polymorphism markers, we show that Wilson's warblers consist of highly distinct western and eastern breeding groups, with all winter samples grouping with the western breeding group. Within the west, there is weak geographic differentiation, at a level insufficient for use in the assignment of wintering samples to specific areas. The distinctiveness of western and eastern genetic groups, with no known intermediates, strongly suggests that these two groups are cryptic species. Analysis of mitochondrial cytochrome b sequence variation shows that the estimated coalescence time between western and eastern clades is approximately 2.3 Ma, a surprisingly old time of divergence that is more typical of distinct species than of subspecies. Given their morphological similarity but strong genetic differences, western and eastern Wilson's warblers present a likely case of association between divergence in migratory behaviour and the process of speciation.

Convention on the Conservation of Migratory Species of Wild Animals

Convention on the Conservation of Migratory Species of Wild Animals

An unintended experiment in fisheries science: a marine area protected by war results in Mexican waves in fish numbers-at-age

Marine protected areas (MPAs) are attaining increasing importance in the management of marine ecosystems. They are effective for conservation in tropical and subtropical areas (mainly coral and rocky reefs), but it is debated whether they are useful in the management of migratory fish stocks in open temperate regions. World War II created a large marine area within which commercial fishing was prevented for 6 years. Here we analyse scientific trawl data for three important North Sea gadoids, collected between 1928 and 1958. Using statistical models to summarise the data, we demonstrate the potential of MPAs for expediting the recovery of over-exploited fisheries in open temperate regions. Our age-structured data and population models suggest that wild fish stocks will respond rapidly and positively to reductions in harvesting rates and that the numbers of older fish in a population will react before, and in much greater proportion, than their younger counterparts in a kind of Mexican wave. Our analyses demonstrate both the overall increase in survival due to the lack of harvesting in the War and the form of the age-dependent wave in numbers. We conclude that large closed areas can be very useful in the conservation of migratory species from temperate areas and that older fish benefit fastest and in greater proportion. Importantly, any rise in spawning stock biomass may also not immediately result in better recruitment, which can respond more slowly and hence take longer to contribute to higher future harvestable biomass levels.Electronic supplementary materialThe online version of this article (doi:10.1007/s00114-010-0696-5) contains supplementary material, which is available to authorized users.

Hypotheses to explain patterns of population change among breeding bird species in England

Population declines are now evident across many taxa, but within each assemblage there is often considerable variation in constituent population trends. We used bird population trends produced from the BTO/JNCC Common Birds Census (CBC) and the RSPB/BTO/JNCC Breeding Bird Survey (BBS), to test five main hypotheses to explain population changes of 59 breeding species in England (1967–2006): (1) breeding habitat, (2) predation risk to nest sites, (3) species climatic niche, (4) migration strategy, and (5) over-wintering bioclimatic zones of migrants, accounting for additional demographic and ecological traits. In absence of phylogenetic inter-relatedness, farmland species declined more than woodland species, most pronounced prior to 1986, probably reflecting agricultural intensification (1). We found limited support that ground nesters have declined more than above-ground or cavity nesters (2), and there was some indication that species with more northerly European distributions showed larger declines than more southerly-distributed species (3). Larger population declines were recorded for Afro-tropical migrants than species wintering in Europe or in the UK, most notable prior to 1986 (4). However, declines were not uniform across all migrants (5) – species over-wintering in the arid savannah bioclimatic zone of Africa decreased in population between 1967 and 1976, whereas species wintering in humid West African forest and savannah declined more after 1987. These results suggest both breeding and over-wintering factors influenced population trends. European countries signed to the Convention on the Conservation of Migratory Species of Wild Animals are required to protect and conserve populations of migrants. Understanding connectivity between breeding and over-wintering populations, and similar environmental pressures experienced within over-wintering areas may be a useful step towards mitigating against further declines in migrants.

Challenging conservation of migratory species: Sahelian rainfalls drive first-year survival of the vulnerable Lesser Kestrel Falco naumanni

In the context of attested global changes, accurate estimation of whether climatic fluctuations impact on population demographic parameters is needed for adequate management, especially for migratory species. We present a capture–recapture analysis linking survival rates of the vulnerable Lesser Kestrel ( Falco naumanni) to annual rainfalls in the Sahel region, considered as a proxy of climatic conditions on wintering grounds. Recapture data were obtained from field observations of individuals ringed and sexed as juveniles over a 14-year monitoring period (1994–2007). We addressed a common but problematic situation in birds where: (i) sex is known with certainty for first-summer or older birds but only suspected for juveniles, and (ii) a large proportion of individuals never return to the study population (e.g. transient behavior). Transient behavior and unknown sexes were explicitly integrated considering a two age class in a multistate capture–recapture model. Survival was time-varying for juveniles (geometric mean: 0.499 ± 0.021) but constant – and higher – for adults (0.718 ± 0.013). Yearling survival probabilities were strongly correlated with rainfalls in the Sahel, suggesting a high dependence of juvenile upon the wintering conditions. While taking sex uncertainty into account, we detected no sex-dependence in survival. Incorporating the sensitivity of survival of wintering migratory birds to climatic variables such as precipitations in arid Sahelian ecosystem may allow to model conservation scenarios with a greater realism. Finally, we encourage the development of international management strategies for migratory species on wintering areas in addition to the existing conservation actions on summering Mediterranean grounds.

Gaining Traction: Retreading the Wheels of Marine Conservation

A number of international treaties address the conservation of marine resources. The declining state of the world's oceans suggests that these treaties are not succeeding and could use improvement. The Convention on International Trade in Endangered Species (CITES) is increasingly embracing the conservation of marine species. We examine the evolution of marine species protection under CITES and illuminate some of the mechanisms used and challenges faced in implementing CITES protection. We found that clarification is needed on when and where CITES applies and how CITES should work with other treaties and institutions. The Society for Conservation Biology (SCB) can contribute to increased effectiveness of CITES for marine conservation. Foremost, the SCB community could foster dialogue on creating a broad vision of how CITES should apply to marine species and how it can synergistically interact with other important marine-conservation treaties and institutions. More specific contributions could focus on defining listing criteria for marine species, improving the science behind the nondetriment finding, and offering technical guidance on species proposals. A future role for SCB could be to contribute to the enhanced effectiveness of other marine conservation agreements such as the Convention on the Conservation of Migratory Species of Wild Animals, the International Whaling Commission, and the United Nations Convention on the Law of the Sea.

CETACEANS IN IRISH WATERS: A REVIEW OF RECENT RESEARCH

CETACEANS IN IRISH WATERS: A REVIEW OF RECENT RESEARCH

IV. Oceans

The key crosscutting issue for the various programs operated under and in association with the United Nations Environmental Programme (UNEP) Regional Seas Programme for 2009 was marine litter, for which a number of developments were advanced. Building on previous initiatives advanced in 2005, significant attention was given to this problem under the broad auspices of the Regional Seas Programme. This culminated in the publication of a global review of the approaches taken to mitigate this issue, as well as Guidelines on the Survey and Monitoring of Marine Litter and Guidelines on the Use of Market-Based Instruments to Address the Problem of Marine Litter. On an allied theme, considerable work was undertaken in association with the Food and Agriculture Organization (FAO) to examine the threat posed by so-called ‘ghost fishing’ with an appraisal of abandoned, lost, or otherwise discarded fishing gear. In October, the eleventh Global Meeting of the Regional Seas Conventions and Global Action Plans was convened in Bangkok, Thailand, with considerable emphasis on climate change and biodiversity conservation, at which the prospects for further collaborative relationships were examined with a host of organizations, including the 1979 Convention on the Conservation of Migratory Species of Wild Animals (CMS Convention), the UN Educational, Scientific and Cultural Organization (UNESCO), the International Union for the Conservation of Nature, and the Nature Conservancy.

Diet and Abundance of the Bat Sturnira lilium (Chiroptera) in a Brazilian Montane Atlantic Forest

We studied variations in diet and abundance of the bat Sturnira lilium (Chiroptera: Phyllostomidae) in a montane Atlantic Forest, in order to investigate if patterns in this habitat differ from those in the better-studied lowlands. The diet of S. lilium was assessed based on fecal samples, whereas possible variations in abundance were documented based on capture success. We also monitored and linked variability in air temperature to fruit production of Solanaceae, the main food of S. lilium. Bats fed exclusively on fruits, mostly on Solanaceae and occasionally on Piperaceae and Cecropiaceae. S. lilium was mostly absent in the area during the colder months, suggesting that they might migrate to lower and hence warmer elevations. Absence of the bats was not related to a distinct decline in availability of fruit of Solanaceae because fruit production was not related to temperature. We conclude that in tropical montane systems, abundance of some frugivorous bats might be affected more by air temperature than by food availability. Furthermore, we reinforce the idea that preserving elevational gradients is a crucial aspect for the conservation of migratory species.