Nomadic Movements Research Articles

Movement and home range of pink abalone Haliotis corrugata: implications for restoration and population recovery

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 486:189-201 (2013) - DOI: https://doi.org/10.3354/meps10365 Movement and home range of pink abalone Haliotis corrugata: implications for restoration and population recovery Julia H. Coates1,*, Kevin A. Hovel1, John L. Butler2, A. Peter Klimley3, Steven G. Morgan3 1Department of Biology, San Diego State University, 5500 Campanile Drive, San Diego, California 92182-4614, USA 2National Marine Fisheries Service, Southwest Fisheries Science Center, 3333 North Torrey Pines Court, La Jolla, California 92037-1023, USA 3Graduate Group in Ecology, University of California, Davis, 1005 Wickson Hall, One Shields Avenue, Davis, California 95616, USA *Email: juliahcoates@gmail.com ABSTRACT: Densities of abalone in southern California have been dramatically reduced by overfishing and disease, leading to the collapse of some populations, and low fertilization rates may be hindering population recovery. This is a pattern typical of abalone species globally. However, movement may produce clustered distributions that promote fertilization success in broadcast spawners, such as abalone, even at low regional densities. We translocated wild, adult pink abalone Haliotis corrugata to an existing pink abalone patch to create a high-density aggregation, and then used acoustic telemetry to characterize abalone movement and monitor aggregation maintenance for a period of 14 mo in the Point Loma kelp forest near San Diego, California. Abalone showed a minimal flight response to handling that did not differ between the resident or translocated groups. Most individuals exhibited small home ranges (median area 183 m2) and homing behavior consisting of regular back-and-forth movement to a single point. Nomadic movement was also observed in several individuals. Though site fidelity may help maintain aggregations, abalone density decreased, and nearest neighbor distances increased at our site to near-initial levels after 18 mo via a combination of mortality, large movements of a few individuals, and small, incremental movements of most individuals. No coordinated movements that would suggest spawning behavior were observed. Translocation of wild abalone to produce aggregations may not result in high rates of fertilization success that promote population recovery. However, the homing behavior observed may provide more opportunities for mating than expectations based on static measures of density and aggregation state. KEY WORDS: Movement · Restoration · Homing · Broadcast spawning · Allee effect · Translocation Full text in pdf format Supplementary material PreviousNextCite this article as: Coates JH, Hovel KA, Butler JL, Klimley AP, Morgan SG (2013) Movement and home range of pink abalone Haliotis corrugata: implications for restoration and population recovery. Mar Ecol Prog Ser 486:189-201. https://doi.org/10.3354/meps10365 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 486. Online publication date: July 12, 2013 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2013 Inter-Research.

Characterizing daily movements, nomadic movements, and reproductive migrations of Panulirus argus around the Western Sambo Ecological Reserve (Florida, USA) using acoustic telemetry

The movements of the Caribbean spiny lobster (Panulirus argus) were studied in three subregions: (1) patch reefs, (2) forereef, and (3) outlier reef, in and around the Western Sambo Ecological Reserve (WSER) (Florida, USA) using acoustic tags and receivers. The studies took place from the June 2003 through July 2007 and involved various receiver deployments such as tracking grids and emigration rings designed to track relatively short daily movements and long-distance (>1km) movements. Daily movements were found to be highly repetitive in some individual lobsters in both the patch reef and the forereef. Some forereef lobsters shifted foraging preference between the forereef itself (63%), a shallow back reef area (10%), reef base (9%), and a deeper reef base area (4%), with undetermined making up the remainder. Approximately one-third of the patch reef resident lobsters exhibited significantly enhanced nocturnal movements during periods of low or no lunar illumination. Twenty-two nomadic movements were detected and occurred throughout the year and included individuals that moved between Western Sambo Ecological Reserve and the outlier reef south of the reserve. Lateral movements detected along the forereef were exhibited by only a few male lobsters. Reproductive migrations by reproductively active female lobsters were observed in all subregions. These movements are characterized by a sudden rapid southward move initiated near midnight. For patch reef and forereef females, the destination is deep water to the south of the forereef. Outlier reef females moved to deeper water to their south. Up to three reproductive migrations were conducted at a median interval of 25 days (16 multiple trips detected). With respect to one of WSER's stated management goals, i.e., to protect life histories, lobster movements have shown that the outlier reef subregion, located 1km south of the southern WSER border, is integral to the spiny lobster life history and should be considered for inclusion into WSER.

BEYOND REPRESENTATION: THE REVOLUTION AS WORD, AS IMAGE, AS EVENT

The “revolution” has been one of the key words in social and political thinking of the last two centuries. After the collapse of the Soviet Union and the closure of the era of political utopias (for many, the point of reference would be 1968 in Paris or in Prague), the word seemed to have vanished entirely from the current vocabulary. However, nowadays we are witnessing the return of the idea of Revolution to the political scene, to the media discourse, to social theory and to art. During the last few years, protest movements have became global and turned to be the real “festivals of resistance”, and this has been perceived as a symptom of the new “revolutionary situation”. The attempts of theoreticians (mostly of the post-Marxist thought) to critically revise the past experience vis-à-vis new political realities seem to be seriously retarded in comparison with the “revolutionary practice”. Passing over to the political scenarios for the future development of the situation, I will focus on the convergence of theoretical discourses on revolution, the new forms of political actionism (“Occupy!” movement, flash-mobs, silent protests, etc.) and the contemporary aesthetic praxis. The history of modern art and cinema has provided a rich iconography of the Revolution as an Event (from Delacrois to Eisenstein and further); however, contemporary art (public art first of all), together with political actionism, tends to follow an entirely different strategy which consists in the circumspect resistance to the logic of representation and is based on the concept of revolution as a perpetual nomadic movement, “becoming”, and evasion.

Determining population trends and conservation status of the common quail (Coturnix coturnix) in Western Europe

In this paper we review the conservation status and population trends of the common quail (Coturnix coturnix) from 1900 to the present. Data are sometimes contradictory with regard to the status of this species as it has some features that make it difficult to produce reliable population estimates. Recent data clearly suggest, either at a local scale or at a trans–national scale, that the Atlantic common quail populations have remained stable in the last two decades, and that restocking practices with farm–reared quails (hybrids with the Japanese quail, Coturnix japonica) do not affect our estimates. The complex movement patterns showed by this species require special attention. Analysis of ring recoveries can give important information, especially about the nomadic movement of quails in search of suitable habitats after the destruction of winter cereal crops due to harvesting. Thus, when developing a breeding distribution model for this species, continuously updated information on seasonal habitat and weather must be included for optimal prediction. Including fortnightly data of vegetation indices in distribution models, for example, has shown good results. Obtaining reliable predictions about changes in species distribution and movements during the breeding period could provide useful knowledge about the conservation status and population trends and would help in the design of future management measures.

The Future of Banding in Raptor Science

Abstract The future of conventional banding in raptor science depends upon the types of questions asked by scientists working in the field, and the extent to which banders and researchers continue their trapping and banding efforts. Traditionally, banding data have played two important roles in raptor science: assessing demographic statistics, including age at first breeding, survival rates, and mortality factors; and tracking movements of raptors, including migration, nomadic movements, and both natal and breeding dispersal. Recent decades have seen an explosive development and use of newer techniques to document the movements of raptors, including color leg-bands, wing-tags, conventional VHF tracking units, satellite-based UHF units, GPS-GSM units, and geolocating data loggers. All of these techniques have greatly facilitated our ability to track the movements of individual birds, broadening the field of movement ecology considerably, and shifting its emphasis from traditional population studies of migr...

The danger of having all your eggs in one basket--winter crash of the re-introduced Przewalski's horses in the Mongolian Gobi.

Large mammals re-introduced into harsh and unpredictable environments are vulnerable to stochastic effects, particularly in times of global climate change. The Mongolian Gobi is home to several rare large ungulates such as re-introduced Przewalski's horses (Equus ferus przewalskii) and Asiatic wild asses (Equus hemionus), but also to a millennium-old semi-nomadic livestock herding culture.The Gobi is prone to large inter-annual environmental fluctuations, but the winter 2009/2010 was particularly severe. Millions of livestock died and the Przewalski's horse population in the Gobi crashed. We used spatially explicit livestock loss statistics, ranger survey data and GPS telemetry to provide insight into the effect of a catastrophic climate event on the two sympatric wild equid species and the livestock population in light of their different space use strategies.Herders in and around the Great Gobi B Strictly Protected Area lost on average 67% of their livestock. Snow depth varied locally, resulting in livestock losses following an east-west gradient. Herders had few possibilities for evasion, as competition for available winter camps was high. Przewalski's horses used three different winter ranges, two in the east and one in the west. Losses averaged 60%, but differed hugely between east and west. Space use of Przewalski's horses was extremely conservative, as groups did not attempt to venture beyond their known home ranges. Asiatic wild asses seemed to have suffered few losses by shifting their range westwards.The catastrophic winter 2009/2010 provided a textbook example for how vulnerable small and spatially confined populations are in an environment prone to environmental fluctuations and catastrophes. This highlights the need for disaster planning by local herders, multiple re-introduction sites with spatially dispersed populations for re-introduced Przewalski's horses, and a landscape-level approach beyond protected area boundaries to allow for migratory or nomadic movements in Asiatic wild asses.

Rainfed areas and animal agriculture in Asia: the wanting agenda for transforming productivity growth and rural poverty.

The importance of rainfed areas and animal agriculture on productivity enhancement and food security for economic rural growth in Asia is discussed in the context of opportunities for increasing potential contribution from them. The extent of the rainfed area of about 223 million hectares and the biophysical attributes are described. They have been variously referred to inter alia as fragile, marginal, dry, waste, problem, threatened, range, less favoured, low potential lands, forests and woodlands, including lowlands and uplands. Of these, the terms less favoured areas (LFAs), and low or high potential are quite widely used. The LFAs are characterised by four key features: i) very variable biophysical elements, notably poor soil quality, rainfall, length of growing season and dry periods, ii) extreme poverty and very poor people who continuously face hunger and vulnerability, iii) presence of large populations of ruminant animals (buffaloes, cattle, goats and sheep), and iv) have had minimum development attention and an unfinished wanting agenda. The rainfed humid/sub-humid areas found mainly in South East Asia (99 million ha), and arid/semi-arid tropical systems found in South Asia (116 million ha) are priority agro-ecological zones (AEZs). In India for example, the ecosystem occupies 68% of the total cultivated area and supports 40% of the human and 65% of the livestock populations. The area also produces 4% of food requirements. The biophysical and typical household characteristics, agricultural diversification, patterns of mixed farming and cropping systems are also described. Concerning animals, their role and economic importance, relevance of ownership, nomadic movements, and more importantly their potential value as the entry point for the development of LFAs is discussed. Two examples of demonstrated success concern increasing buffalo production for milk and their expanded use in semi-arid AEZs in India, and the integration of cattle and goats with oil palm in Malaysia. Revitalised development of the LFAs is justified by the demand for agricultural land to meet human needs e.g. housing, recreation and industrialisation; use of arable land to expand crop production to ceiling levels; increasing and very high animal densities; increased urbanisation and pressure on the use of available land; growing environmental concerns of very intensive crop production e.g. acidification and salinisation with rice cultivation; and human health risks due to expanding peri-urban poultry and pig production. The strategies for promoting productivity growth will require concerted R and D on improved use of LFAs, application of systems perspectives for technology delivery, increased investments, a policy framework and improved farmer-researcher-extension linkages. These challenges and their resolution in rainfed areas can forcefully impact on increased productivity, improved livelihoods and human welfare, and environmental sustainability in the future.

Seasonal Distribution and Range of the Blackish-Blue Seedeater (Amaurospiza moesta): A Bamboo-Associated Bird

Abstract Avian bamboo specialists are an ecologically distinctive group of birds in the Neotropics with some seedeater species having nomadic movements following bamboo (Guadua, Chusquea or Rhipidocladum) mast seeding. We reviewed the range and seasonal distribution of Blackish-blue Seedeaters (Amaurospiza moesta) using published and unpublished records, museum specimens, sound libraries, and intensive field work. We report the first occurrence of Blackish-blue Seedeaters in the Brazilian State of Mato Grosso, a male collected in Fazenda Baia de Pedra, Caceres (16° 27′ 29″ S, 58° 09′ 59″ W). We also recorded this species in two localities in the Cerrado region (a tropical savannah) of Minas Gerais: the Santo Antonio River, Presidente Olegario (18° 07′ 48″ S, 46° 11′ 57″ W), and the Abaete River, Sao Goncalo do Abaete (18° 05′ S, 45° 22′ W). These records represent a remarkable range extension, demonstrating this species is distributed across the Cerrado. We found no evidence of regular large scale or loca...

Territorializing ethnicity: the imposition of a model of statehood on pastoralists in northern Kenya and southern Ethiopia

The idea of the nation state has penetrated Kenya and Ethiopia deeply at a level much below the ‘nation’ state. In the colonial period districts and grazing reserves were delineated according to perceived ‘tribal’ boundaries, which were often only created in the process. Ethnicity in that process was not invented (as has been claimed for other parts of Africa) but it has changed: it has acquired a territorial character of a new kind. Ethnic territoriality in the mind of policy makers combined with ideas of preservation of the range which modern range ecology would regard as misconceived. These ideas led to policies that restricted the range of movement of pastoral nomads. This paper draws a line from colonial policies to modern politics, in which territorial subdivision continues. This process seems to be guided the interests of self-styled elites, while the pastoralists are adversely affected by them.

Death by a thousand huts? Effects of household presence on density and distribution of Mongolian gazelles

In late spring 2005, we surveyed Mongolian gazelle (Procapra gutturosa) populations in a 275,000-km2 portion the eastern steppe of Mongolia to estimate their population size and assess their distribution with respect to forage and human households. We estimated a total population of 1.126 million (95% CI, 843,000–1,500,000), and found that gazelle distribution could be accurately predicted by a Normalized Difference Vegetation Index (NDVI) as an approximated measurement of vegetation productivity, and thus habitat quality. However, the presence of households had a considerable impact on gazelle density; in most regions, density was 76–98% lower than in survey blocks where no households were found. We show that in addition to large regional differences in gazelle density throughout their range, the presence of herding households had a negative impact on gazelle density in selected habitat. The conservation of ungulates that depend on the ability to make long-distance nomadic movements requires not only that access to habitat is unimpeded but also that the subtle impacts of activities associated with the presence of people need to be considered.

Passion's re-territorializations: mapping the mixed semiotics of unsafe homo passional assemblages

This paper conducts a mixed semiotics of unsafe homo passional assemblages. It begins with an exposition of Deleuze and Guattari's instructions for mapping the multidimensional circuitry of assemblages along the generative and transformative poles. Unsafe sex is a line of desiring movement involving expressive matter from the pick-up machine. After HIV/AIDS, the pick-up machine's de-territorialised movements have been problematised, their a-semiotic matter becoming a testimony to the limits of the imperative to practice safe sex. These assemblages have been overcoded as being unconscious and ineffable; however, this paper traces their mixed semiotics involving the a-signifying particle-signs of the pick-up machine as well as conscious lines of desiring movement involving the segmentarity and mirror vision of a recognisable social identity as a gay man. In all of these passional assemblages the pick-up machine's nomadic movements have become buckled by a number of sovereign, consuming microfascisms. The lines of movement have reached their threshold limit, weakening their capacity for making new connections for new lines of becoming and creative mutation. Throughout the paper it is argued that the macropolitics of safe sex has failed to grasp the possibilities for new passages that can be drawn from the molecular soup of the pick-up machine and its micropolitics of perception, affection and conversation. It is not necessary to prohibit its lines of movement as new possibilities for homo sexual culture will emerge by drawing on affective potentials drawn from the pick-up machine in conjunction with new affective material.

Annual movements of Mongolian gazelles: Nomads in the Eastern Steppe

Determining the scale and pattern of, and the influences on, the movements of Mongolian gazelles is important because their numbers and range have been reduced significantly, and their remaining grassland habitat faces further fragmentation and degradation. Therefore, during 2000–2005 we monitored movements of individually marked Mongolian gazelle calves and adult females in the Eastern Steppe of Mongolia to identify variation in seasonal range sizes and locations, group sizes, and range characteristics. Annual range size for calves varied over an order of magnitude (800–18 700 km 2), and none of 9 calves tracked for a full year returned to their birth site. Adult gazelles ranged widely (14 000–32 000 km 2 annually) and individuals captured together showed little range overlap. Seasonal shifts in range use suggested gazelles are readily able to take advantage of changing conditions, but the lack of consistent use of seasonal ranges is characteristic of a nomadic movement strategy. Developing strategies that protect ungulate populations that demonstrate nomadic movements is an important consideration in future conservation decisions. Understanding the ecology driving these movements will be an important next step.

Net contribution of spillover from a marine reserve to fishery catches

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 400:233-243 (2010) - DOI: https://doi.org/10.3354/meps08419 Net contribution of spillover from a marine reserve to fishery catches Raquel Goñi1,*, Ray Hilborn2, David Díaz1, Sandra Mallol1, Sara Adlerstein3 1Centro Oceanográfico de Baleares, IEO, Muelle de Poniente s/n, 07015 Palma de Mallorca, Spain 2School of Aquatic and Fishery Sciences, PO Box 355020, University of Washington, Seattle, Washington 98195, USA 3School of Natural Resources and Environment, University of Michigan, 3010 Dana Building, Ann Arbor, Michigan 48109-1115, USA *Email: raquel.goni@ba.ieo.es ABSTRACT: Benefits for fisheries from marine protected areas (MPAs) are expected from recruitment of exported eggs and larvae as well as from spillover of adults to adjacent fishing grounds. Because the recruitment effect is difficult to detect, spillover is presently the only tangible potential fishery benefit of MPAs. Despite abundant evidence of spillover in the literature, this is the first study to quantify the number and biomass of individuals annually spilling over from an MPA and their contribution to the local fishery catches. Using a decade (1997–2007) of tag-recapture data for the lobster Palinurus elephas from the Columbretes Islands Marine Reserve (CIMR), we estimated annual emigration probabilities of 3.7% (female) and 6.7% (male), and quantified the resulting spillover to adjacent fished areas. We showed that during an 8 to 17 yr protection period, harvested spillover offset the loss of yield resulting from the reduction of fishing grounds set aside in the CIMR, producing a mean annual net benefit of 10% of the catch in weight. Although the number of lobsters spilling over annually did not quite make up for the loss of fishing grounds in the CIMR, it did in weight because the mean size of the lobsters emigrating from the reserve was larger than that of those outside. We propose that nomadic or home range movements of individuals near MPA boundaries, seasonal migrations and migrations forced by extraordinary meteorological events, and density-dependent movements facilitated spillover from the CIMR. Fishing effort concentration along its boundaries and high exploitation rates in the local fishery limited the spatial extent of spillover. KEY WORDS: Marine reserve · Marine protected area · Spillover · Adult emigration · Fishery benefits · Commercial catch · Dispersion imbalance · Competitive exclusion · Lobster · Artisanal fisheries Full text in pdf format PreviousNextCite this article as: Goñi R, Hilborn R, Díaz D, Mallol S, Adlerstein S (2010) Net contribution of spillover from a marine reserve to fishery catches. Mar Ecol Prog Ser 400:233-243. https://doi.org/10.3354/meps08419 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 400. Online publication date: February 11, 2010 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2010 Inter-Research.

Extended Primary Moult as an Adaptation of Adult Wood SandpipersTringa glareolato Their Freshwater Habitats in Southern Africa

Migrant waders using freshwater habitats are hypothesized to have slower primary moult than waders using coastal habitats. We chose the Wood Sandpiper Tringa glareola as a representative species using the freshwater habitats and compare its moult pattern with a range of fresh-water and coastal wader species to test the habitat hypothesis. Only fragmentary descriptions of Wood Sandpipers' primary moult in their sub-Saharan non-breeding quarters had existed. We analysed the primary moult formulae of 1496 adult Wood Sandpipers obtained in southern Africa. The Underhill & Zucchini moult model was used to estimate the timing and duration of moult for all 10 primaries combined and for each primary individually. We also estimated the rate of production of feather material during moult. Adult Wood Sandpipers arrive in southern Africa between late July and November, and depart from mid-March to April. Suspension of moult was observed in 56 birds (7.5%) after two to nine primaries had been replaced. The remaining birds performed a continuous complete primary moult, with average start and completion dates of 21 August and 30 December, respectively; estimated duration was 131 days. The overall rate of production of primary feather material was uniform, achieved by growing up to five small inner primaries simultaneously at the beginning of the moult but only one or two simultaneously while the large outer primaries were growing. Primary moult of adult Wood Sandpipers took longer but ended earlier than in similar-sized waders using coastal habitats. Compared with waders using coastal habitats, Wood Sandpipers prolonged moult by shedding their primaries at longer intervals and by extending the growth period of each primary. The longer primary moult and its earlier ending compared with coastal waders are probably adaptations to Wood Sandpipers' use of freshwater habitats, which in southern Africa provide unpredictable food supplies and might require nomadic movements between ephemeral inland wetlands.

Fences Impede Long-distance Mongolian Gazelle (Procapra gutturosa) Movements in Drought-stricken Landscapes

Human-generated landscape barriers are especially problematic for species whose life histories entail long-distance movements. In May 2008, hundreds of Mongolian gazelles (Procapra gutturosa) became entangled in border fences as thousands attempted to move from Mongolia into Russia. Typically, the root cause of such (non-migratory) mass animal movements can only be superficially described. Here we draw upon satellite imagery and a fortuitously timed field study to investigate a likely hypothesis. At the same time that gazelles were attempting to cross from Mongolia into Russia, gazelles equipped with satellite-linked collars repeatedly attempted to emigrate from Mongolia into China. Satellite-derived estimates of vegetation productivity demonstrate that a decade-long decline in available green biomass in Mongolia’s steppes underlies the gazelles’ attempted mass emigrations. Given the potential that this trans-boundary movement event will occur within these drought-stricken landscapes in the future, modest fence modifications suitable for other similar open habitat ungulates may be sufficient to allow the gazelles to maintain their nomadic movements.

The Fate of Coho Salmon Nomads: The Story of an Estuarine-Rearing Strategy Promoting Resilience

The downstream movement of coho salmon nomads (age 0), conventionally considered surplus fry, has been an accepted characteristic of juvenile coho salmon for the past 40 to 50 yr. The fate of these nomads, however, was not known and they were assumed to perish in the ocean. Several studies and observations have recently provided new insights into the fate of nomads and the role of the streamestuary ecotone and estuary in developing this life history strategy that promotes coho resilience. Chinook and sockeye salmon have developed the ocean-type life-history strategy to exploit the higher productivity of the estuarine environment and migrate to the ocean at age 0. Nomad coho can acclimate to brackish water, and survive and grow well in the stream-estuary ecotone and estuary, but instead of migrating to the ocean they return upstream into freshwater to overwinter before migrating to the ocean as smolts. Nomads may enter the estuarine environment from natal or non-natal streams, rear there throughout the summer, and then emigrate to a non-natal stream for overwintering and smolting in the spring. These estuarine and overwintering habitats have enabled coho to develop this unique nomad life history strategy that may help to ensure their resilience. Restoring estuarine habitats may be essential to the recovery of depressed populations of coho.

Use of satellite telemetry on small-bodied waterfowl in Australia

The nomadic or dispersive movements of many Australian waterfowl in response to irregular environmental cues make satellite telemetry studies the only means by which these long-distance movements can be tracked in real time. Unlike some large-bodied soaring species, attaching satellite transmitters to small-bodied waterfowl (<1 kg) is not straightforward because ducks have high wing loadings and need to maintain active flapping to stay aloft. In the present paper, we detail one harness design and attachment method that enabled us to track grey teal (Anas gracilis) for up to 879 days. In addition, we detail rates of data loss, changes in data quality over time and variation in data quality from solar-powered satellite-tags deployed on ducks in Australia and Papua New Guinea. Up to 68% of all locational fixes have a nominal accuracy of less than 1 km, and satellite-tags deployed on wild birds can provide up to 22 location fixes per day and store enough energy during the day to run continuously throughout the night.

A mega-herd of more than 200,000 Mongolian gazelles Procapra gutturosa: a consequence of habitat quality

In September 2007 unusual precipitation patterns created conditions in the eastern steppe of Mongolia (drought conditions in many places and wet conditions in one area) that led to the observation of a historically large Mongolian gazelle Procapra gutturosa herd (> 200,000). A model developed to predict gazelle occurrence based on satellite imagery of vegetation productivity correctly identified the region where the mega-herd was located. Additionally, few gazelles were observed in large portions of adjacent, suitable habitat that either had intense insect activity or were undergoing intensive oil development. Because Mongolian gazelles appear to undertake long-distance nomadic movements to cope with a highly variable environment and food availability, development activities that discourage use of limited suitable habitat may ultimately reduce gazelle fecundity or increase mortality. Landscape level conservation strategies that prevent habitat loss and allow access to all of the grasslands seem preferable to strategies that focus on enhancing a handful of protected areas.

Birds from the Far East in Central Europe: some side-notes to Pfeifer et al. (2007)

The “reverse migration hypothesis” as the explanation for the vagrancy of Far Eastern birds in Europe is commented on. It is concluded that, as the postulated switch of 180° along a great circle line would lead the eastern or even central Siberian birds to North America rather than to Europe, the application of the “reverse migration hypothesis” to them seems untenable (which, however, does not preclude its plausibility in case of transatlantic, southern European, or even southwestern Siberian vagrants). On the other hand, patterns of appearance of the Turdus [naumanni] superspecies (Machalska et al. 1967) suggest the relationship of the phenomenon of vagrancy to post-breeding nomadic movements and/or periodical invasions of non-migrating species.

Home, Capital of the Region

Home, Capital of the Region