Potential Breeding Areas Research Articles

Year-round presence of northern and southern hemisphere Blue Whales (Balaenoptera musculus) at the Galapagos Archipelago.

Information about blue whales (Balaenoptera musculus) in the Eastern Tropical Pacific is scarce with only few whales sighted within the last decades. Molecular, photo ID and acoustic studies suggest a connectivity of Chilean and Antarctic blue whales to potential breeding areas off the coast of Peru and in the Galapagos, whereas blue whales of the Costa Rica Dome relate to the Northern Hemisphere population feeding off the coast of California and breeding areas are yet unknown.
 With opportunistic sighting records in the Galapagos, we document group size and distribution throughout the year during a 17-year period from 2001 to 2018. Sightings slightly increased during the study period with 50% of the whales seen as singletons. Whales were seen year-round but mostly during the Austral winter (82%) and calf sightings occurred from June to September. With 18% of the sightings occurring during the Austral summer, we propose there is geographical overlap between equatorial Galapagos and Northern hemisphere blue whales. One blue whale was identified in the Galapagos in February 2009, resighted in the Costa Rica Dome in January 2014, and sighted again in the Galapagos in May 2016, when whales from the Southern Hemisphere could already be present. The fact that blue whale sightings were recorded throughout the year and the identified individual strongly suggest a non-migratory blue whale population and that in the Galapagos overlapping of both North and South East Pacific blue whale populations can occur.

Dead Sea level decline pushed a sensitive ecosystem out of equilibrium, causing the relocation of a colonial bird breeding site

ABSTRACT Capsule Dead Sea Sparrows Passer moabiticus transferred their historical breeding colony location, following geo-ecological and hydrological changes, to a new, less arid zone within a nature reserve. Aims To find biotic and abiotic factors affecting the choice of nest sites by Dead Sea Sparrows, in order to locate potential breeding areas and plan in advance for their protection. Methods Mapping old and new nest sites of Dead Sea Sparrows within Einot Tzukim nature reserve, Dead Sea Valley, and using anthropogenic and geo-ecological GIS layers, we created a map of the potential preferred breeding colony area. Results We found the biotic and abiotic factors affecting nest site preference of Dead Sea Sparrows, which included areas far from human activity, areas close to historic springs, and areas affected by a major fire. New areas in the reserve exposed by the retreating Dead Sea were inhabited by the birds, which gradually transferred their breeding centre to a less arid zone within the reserve. Conclusion When managing colonial breeding sites, it is crucial to understand the role of both natural and anthropogenic influences in order to prioritize sites for conservation and management. Producing a preference map, based on such data, can help managers locate potential breeding areas and plan in advance for their protection.

Timing of mating, reproductive status and resource availability in relation to migration in the painted lady butterfly

In many migratory insects, migration occurs during the prereproductive phase of the life cycle. This trait probably arises from a trade-off between migration and reproduction and in females has been termed the ‘oogenesis–flight syndrome’. However, the generality of this syndrome has been questioned, especially for monomorphic insects. We studied the relationship between migration and reproduction in the highly cosmopolitan painted lady butterfly, Vanessa cardui , which in the Palaearctic undertakes the longest known multigenerational migration circuit of any insect. We tested for the oogenesis–flight syndrome in both spring and autumn migrants in two regions linked by migration, North Africa and northern Spain. Field observations were combined with laboratory experiments to determine the life span and the age at first mating to unravel the reproductive strategy observed in wild-caught individuals. Females and males wait on average around 5–6 days before mating, and field data revealed that mating frequencies increased rapidly once females reached a medium wing wear category. There were seasonal differences in mating frequencies in the study regions depending on whether the region acted as a source or as a destination for migrants, and in the latter case there were almost twice as many mated females. Moreover, a great majority of females collected during migratory flights were unmated, the remaining females having mated only very recently. Our results thus strongly indicate that the painted lady fulfils the oogenesis–flight syndrome, as migration is concentrated in its relatively short prereproductive period. Field data also showed a high positive correlation between mating frequency and host plant abundance, which suggests that mated females are able to locate potential breeding areas. This, together with the high fecundity estimated in laboratory trials, makes the painted lady a highly successful migratory insect. • Females and males wait on average around 5–6 days before mating. • Migration is concentrated in the relatively short prereproductive period. • The painted lady is one of the most fecund of all butterfly species. • Mated females have a good ability to locate potential breeding areas. • These traits form a migration syndrome and allow a successful migratory strategy.

Assessment of the American Flamingo distribution, trends, and important breeding areas.

The American Flamingo, Phoenicopterus ruber, is a charismatic bird distributed throughout the Caribbean, North and South America. Its wide distribution, the complexity of international monitoring due to its capacity for long-distance flying, and a focus mostly on local populations, make it difficult to understand the dynamics between sites. Here, we took advantage of the citizen eBird science project to present a global perspective on the distribution of the American Flamingo, and identify the potentially most important countries for breeding. We obtained 16,930 records for the Americas from the 1960s until October 2018, of which 9,283 could be used for our objectives. The eBird database indicated a considerable increase in the total number of records over the last decade (2010s), probably reflecting an increase in tourism facilities, research investment, technological advancement, interest in conservation, and the worldwide availability of eBird. We also observed a range extension in the Gulf of Mexico in the United States and a significant recolonization in the Florida Peninsula. The apparent range extension to the South is more likely to be linked to biases in the data; for example, in any given country the number of records might reflect either reporting efforts or actual numbers. eBird data confirmed that six countries host the main breeding colonies (Bahamas, Bonaire, Cuba, Ecuador, Mexico, and Venezuela). We suggest three additional countries as potential breeding areas for the species (Colombia, Curaçao, Turks and Caicos Islands) for which more field observations are necessary to support this possibility. This global appraisal of the distribution of the American Flamingo using citizen science data provides valuable information for national and international management and conservation programs such as the need to verify the species breeding status in areas where it appears to be expanding its distribution.

Estimating the invasion extent of Asian swamp eel (Monopterus: Synbranchidae) in an altered river of the south-eastern United States

The first reported invasion of Asian swamp eels (Monopterus albus, ASE) in the continental United States was in the state of Georgia in 1994. This population was first discovered within several ponds on a private nature centre, but the ponds drained via an outflow pipe into marsh habitats along the Chattahoochee River. Our objective was to delineate the current invasion extent of ASE in the Chattahoochee River, Georgia, by sampling juvenile ASE within an occupancy modelling framework. We sampled 111 and 100 sites in 2015 and 2016 respectively, on 10 occasions, each within a 2-km radius of the purported invasion point to estimate the spatial extent of their invasion in this system. Leaf-litter traps (LLTs) were effective at documenting an increase in the invasion extent of ASE, from within 100m of the Chattahoochee Nature Center pond outflow to 1.6km away. Documenting the extent of invasion of this population has proven elusive in the past, but the use of LLTs to target juvenile eels has documented a larger invasion extent than previously known in the study system. The results of this research can be used to develop effective control and management strategies, such as locating potential breeding areas for targeted removal sampling.

Estimating risk to ice-breeding pinnipeds from shipping in Arctic and sub-Arctic seas

Industrial shipping activity in some Arctic and sub-Arctic seas is increasing during the winter and spring seasons of heavy ice cover. Here, following from a previous study of icebreaker impact on seals in the Caspian Sea, the extent of overlap between shipping and breeding habitat of ice-associated pinnipeds in other seas is investigated. Significant industrial shipping activity in potential pinniped breeding areas during the spring pupping period 2017 was recorded in the Baltic Gulfs of Finland and Bothnia (grey and ringed seals), the White Sea and Newfoundland Belle Isle Strait (harp seal), the Ob Estuary in the Kara Sea (ringed seal), The Pechora Sea (walrus) and Sakhalin Island area in the Okhotsk sea (ringed, bearded, ribbon and spotted seals). Most areas lack sufficient pup density distribution data to apply quantitative evaluations, but for the Caspian and White Seas it was possible to estimate a measure of vessel disturbance in terms of the potential number of collisions with pups in the path of a single vessel of a given beam width, giving a result of 9.6% of Caspian seal pups and 1.9% of White Sea harp seal pups in the 2006 and 2009 seasons respectively. This study highlights the need to consider policy and regulatory frameworks for vessels transiting pinniped ice breeding areas in advance of further growth in vessel traffic during winter and spring. Stakeholders operating shipping through pinniped breeding habitat in sea ice could play a role in generating the data necessary for such impact assessments and evidence-based mitigation measures.

Assessing Mosquito Breeding Sites and Abundance Using An Unmanned Aircraft.

An unmanned aircraft system (UAS; i.e., drone) with an attached multispectral camera was used to quantify accumulated surface water on a 0.54-km2 tidal marsh that abuts San Francisco Bay, CA, USA. The results of the survey showed unequal accumulation of surface water and provided information for focused inspections of potential mosquito breeding areas and identified areas where existing ditches needed improvement for increasing water circulation in the marsh to reduce mosquito breeding. The UAS was also outfitted with a high-magnification zoom video camera and piloted at varying heights to measure the video camera's ability to visualize immature mosquitoes in 2 small containers of contrasting colors during simulation tests in a marsh habitat. Immature mosquitoes could be seen clearly in white or black containers at heights up to 14 and 8 m, respectively. An artificial intelligence algorithm identified mosquito larvae and pupae in videos of the white tray with 94.1% and 52.8% accuracy, respectively. Together, our studies show that an UAS equipped with multispectral and zoom cameras provides a means for vector control agencies to rapidly and quantitatively assess the landscape for the presence of surface water and mosquito larvae.

Potential migratory routes of Urania boisduvalii (Lepidoptera: Uraniidae) among host plant populations

AbstractAimMigratory species depend on various habitats and resources along their migration routes. Characteristics such as dependence on distinct habitats and the presence of multiple threats along their migratory routes make these species vulnerable, and gaps in knowledge about their ecology and migration processes make them difficult to conserve. Urania boisduvalii is a diurnal moth endemic to Cuba that feeds on plants of Omphalea spp. during its larval phases. These plants produce secondary metabolites as a defence against the moth's larvae, which then are forced to migrate. Although some ecological aspects of Urania boisduvalii are known, its migration routes remain largely unknown. This research proposes potential migratory routes of Urania boisduvalii among populations of its host plant.LocationCuba.MethodsWe developed ecological niche models of the moth and its hosts based on environmental, anthropic, biotic and biogeographic factors to obtain potential distributional areas that include zones where positive interactions are found but exclude those where negative factors are present. These areas were overlapped to hypothesize potential breeding areas for the moths. Potential migratory corridors were proposed based on environmental connectivity.ResultsThe moth and its hosts have broad potential distributions; however, limiting factors have substantially reduced these areas, especially for plants. The potential migratory routes of Urania boisduvalii are complex and mostly involve the western and eastern regions of Cuba. Most records outside potential breeding areas were close to these migratory corridors.Main conclusionsWe offer initial hypotheses of the migratory routes of U. boisduvalii, which may be useful to guiding monitoring projects that can provide more definitive views of the seasonal distribution of this species across the Cuban archipelago.

Machine Learning Model Analysis of Breeding Habitats for the Black-necked Crane in Central Asian Uplands under Anthropogenic Pressures

The black-necked crane (Grus nigricollis) is the only alpine crane species and is endemic to the Tibetan Plateau. The breeding habitats of this species are poorly understood, which greatly hampers practical research and conservation work. Using machine learning methods and the best-available data from our 7,000-kilometer mega-transect survey and open access data, we built the first species distribution model (SDM) to analyze the black-necked crane’s breeding habitats. Our model showed that current conservation gaps account for 26.7% of its predicted breeding habitats. Specifically, the northern parts of the Hengduan Mountains and the southeastern Tibet Valley, the northern side of the middle Kunlun Mountains, parts of the Pamir Plateau, the northern Pakistan Highlands and the western Hindu Kush should be considered as its main potential breeding areas. Additionally, our model suggested that the crane prefers to breed in alpine meadows at an elevation over 2,800 m, a maximum temperature of the warmest month below 20.5 °C, and a temperature seasonality above 7,800 units. The identified conservation gaps and potential breeding areas can aid in clearly prioritizing future conservation and research, but more attention and study should be directed to the unassessed Western Development of China to secure this endangered crane lineage and other wildlife on the Tibetan Plateau.

The potential breeding range of Slender-billed CurlewNumenius tenuirostrisidentified from stable-isotope analysis

SummaryThe breeding areas of the Critically Endangered Slender-billed CurlewNumenius tenuirostrisare all but unknown, with the only well-substantiated breeding records being from the Omsk province, western Siberia. The identification of any remaining breeding population is of the highest priority for the conservation of any remnant population. If it is extinct, the reliable identification of former breeding sites may help determine the causes of the species’ decline, in order to learn wider conservation lessons. We used stable isotope values in feather samples from juvenile Slender-billed Curlews to identify potential breeding areas. Modelled precipitationδ2H data were compared to feather samples of surrogate species from within the potential breeding range, to produce a calibration equation. Application of this calibration to samples from 35 Slender-billed Curlew museum skins suggested they could have originated from the steppes of northern Kazakhstan and part of southern Russia between 48°N and 56°N. The core of this area was around 50°N, some way to the south of the confirmed nesting sites in the forest steppes. Surveys for the species might be better targeted at the Kazakh steppes, rather than around the historically recognised nest sites of southern Russia which might have been atypical for the species. We consider whether agricultural expansion in this area may have contributed to declines of the Slender-billed Curlew population.

Use of lapillus otolith microchemistry as an indicator of the habitat of Genidens barbus from different estuarine environments in the southwestern Atlantic Ocean

The marine catfish Genidens barbus is an anadromous species from South America. The aim of the present study was to evaluate the use of lapillus otolith microchemistry (Sr:Ca; Ba:Ca and Mg:Ca ratios) as an indicator of changes in habitat use and identify the potential breeding areas and fish stocks of G. barbus populations from the Plata Basin (Parana River Delta and De la Plata River estuary-Argentina) and Lagoa dos Patos coastal lagoon (southern Brazil). Sr:Ca, Ba:Ca and Mg:Ca ratios were measured in the core area (inner 4 rings) and external area (outer 3–4 rings) of the otoliths by ICP-OES. The Sr:Ca ratio tended to be higher in the otolith external area than in the core area, while the Ba:Ca ratio followed the opposite pattern. This suggests the displacement of fish toward higher salinity areas. The Sr:Ca, Ba:Ca, Mg:Ca ratios in the core and external areas of the otoliths from the Plata Basin differed significantly from those of the otoliths from Lagoa dos Patos. This may indicate the occurrence of two different breeding sites and at least two fish stocks in the study region.

Enriching the isotopic toolbox for migratory connectivity analysis: a new approach for migratory species breeding in remote or unexplored areas

AbstractAimWe examined three potential enhancements of the stable isotope technique for elucidating migratory connectivity in birds inhabiting poorly studied areas, illustrated for Eurasian cranes (Grus grus) that overwinter in and migrate through Israel. First, we examined the use of oxygen stable isotopes (δ18O), seldom applied for this purpose. Second, we examined the relationship between ambient water δ18O and hydrogen stable isotope (δ2H) values derived from various models, to determine the geographical origins of migrants. Third, we introduced the use of probabilistic distribution modelling to refine the assignment to origin of migrants lacking detailed distribution maps.LocationFeather samples were collected in the Hula Valley (northern Israel) and across the species breeding range in north Eurasia.MethodsWe analysed δ18O and δ2H in primary and secondary flight feathers using standard mass spectrometry. The maximum entropy (maxent) model was used to map the probability surface of potential breeding areas, as a Bayesian prior for assigning Hula Valley cranes to potential breeding grounds.ResultsWe found that δ18O was suitable and informative. The soil water isoscape performed better for δ18O while precipitation isoscape was preferable for δ2H. The maxent‐based probability surface largely refined assignments. Overall, most (>85%) cranes were assigned to the area west of the Ural Mountains, but for two individuals, most of the assigned area (>90%) was farther east, suggesting, for the first time, that Eurasian cranes may undertake the North Asia–Middle East (and perhaps Africa) migration flyway.Main conclusionsOur results call for broader use of δ18O in migratory connectivity studies and for application of probabilistic distribution modelling. We also encourage investigation of factors determining δ18O and δ2H integration into animal tissues. The proposed framework may help improve our understanding of migratory connectivity of species inhabiting previously unexplored areas and thus contribute to the development of efficient conservation plans.

The population size and breeding range of the Scaly-sided MerganserMergus squamatus

SummaryBased on surveys during 2000–2012 and best available knowledge, we estimate the global population size of the Endangered Scaly-sided MerganserMergus squamatusto be c.1,940 pairs (or c.4,660 birds prior to reproduction). In Russia, surveys identified the breeding range in the Sikhote-Alin mountain range and the area adjoining the lower Amur River. Particular effort was made to define the edge of the range. Breeding densities in the Sikhote-Alin were applied to un-surveyed rivers within the range to estimate overall numbers. The breeding range comprises c.7,800 km of 120 rivers: 6,800 km in Russia, 600 in China and 400 in DPR Korea. In Russia it comprises 88 rivers of both the western and eastern slopes of the Sikhote-Alin Range, and two small isolated areas, one in central Khabarovsk and the other in the Jewish Autonomous Oblast. All known and potential breeding areas were surveyed in China, where the breeding range comprises the western slope of the Changbai Mountains, and one isolated river system in the Lesser Xingan Mountains. Scaly-sided Mergansers are also assumed to breed on the eastern slope of the Changbai Mountains in DPR Korea. No recent surveys have been made there but numbers were estimated by applying densities from China to rivers with apparently suitable habitat. Detailed examination of past records suggests that an earlier claim of breeding Scaly-sided Mergansers on the Dep River was erroneous and we conclude that the breeding range never extended as far west as has been portrayed in most literature. The lack of comparable surveys previously precludes an assessment of change in population range or size, though it seems inevitable that habitat loss in China is likely to have resulted in some loss of range and numbers, particularly in Heilongjiang Province, in recent decades.

Rapid and continued population decline in the Spoon-billed Sandpiper Eurynorhynchus pygmeus indicates imminent extinction unless conservation action is taken

SummaryThe Spoon-billed Sandpiper Eurynorhynchus pygmeus (IUCN Category: Critically Endangered) is in rapid decline. Data from across the entire breeding range (Chukotka and Koryakya in the Russian far north-east) and especially from the well-studied southern core breeding area at Meinypilgyno, confirm the continuing strong decline. At four breeding sites, where more than two counts were available for analysis, the decline was estimated at 26% per annum between 2002 and 2009, or an 88% decline over this period. Allowing for unsurveyed areas, this equates to a decline from a total population of approximately 1,000 breeding pairs in 2000 to 120–220 in 2009. Breeding studies at Meinypilgyno in 2003–2007 (not 2006) showed that the proportion of nests hatching at least one chick was 0.65 and once chicks left the nest, the mean brood size of chicks up to one week old was 1.99. Where it was possible to follow broods, 0.61 chicks fledged per nesting attempt. Survival and recruitment analysis of birds ringed at Meinypilgyno indicated that annual adult survival did not significantly differ over the 2003–2009 study but that recruitment in to the adult breeding population was effectively zero in all but one year of the study (2005). Resighting data for the last two years of the study were sparse due to very low numbers of marked adults being recorded and survival rates over the last 2–3 years of the study must therefore be treated with caution. The analysis therefore indicated that after fledging, survival during immaturity must be very low, leading to a low (or no) recruitment into an ageing population. Recent observations collated from the non-breeding areas confirm the declining trend observed in the breeding areas and imply that the main threats to the population lie along the migration route or in the wintering areas. These are poorly known although hunting in the wintering areas has been identified as a major mortality factor. Other threats include major loss of their intertidal habitats, and collection of birds on the breeding areas by specimen collectors. Improved monitoring in both the breeding and non-breeding areas as well as research on juvenile survival is recommended. Concerted international conservation action is essential if this species is to avoid extinction. This requires (i) improved understanding of the main wintering and staging areas and associated threats; (ii) addressing those threats that can be tackled with immediate effect, such as hunting; (iii) continued long-term monitoring on the breeding areas; (iv) an exploration of other potential breeding areas; (v) conservation action at all important stop-over and wintering sites along the entire flyway and (vi) consideration of a captive-breeding programme to ensure the survival of this species.

Migration patterns, breeding and moulting locations of king eiders wintering in north-eastern Norway

The Norwegian coast is a very important winter area for king eiders (Somateria spectabilis), but their origin has been unknown. We determined spring and autumn migration routes, timing of migration and potential breeding areas of king eiders wintering in north-eastern Norway using implanted satellite transmitters. Five males and five females were equipped with transmitters in February 2008, and location data were received from six birds. All birds departed within 10 days in mid April and flew to the Pechora Sea and Kara Sea in western Russia where they staged until mid June. Subsequently, four of five birds with active transmitters (two females and two males) moved east to potential breeding locations on the Gydan and Taymyr Peninsulas. In early July, the males moved west to moult at Kolguyev Island and in the Pechora Sea. The two females departed in mid July, one probably moulting between the gulfs of the Ob and Yenisei Rivers, after which it moved to the Pechora Sea. The other female probably moulted in the eastern Taymyr, thereafter moving to Novaya Zemlya. This female returned to the north-eastern coast of Norway 1 December, while the other female returned 2 January. For the males, the transmitters stopped in December/January when they were still in the Pechora/Kolguyev area. King eiders wintering in north-eastern Norway thus originate from the western half of Arctic Russia, and the Taymyr Peninsula is probably the dividing point between the eastern and western flyways.

Timing of initial arrival at the breeding site predicts age at first reproduction in a long-lived migratory bird

In long-lived vertebrates, individuals generally visit potential breeding areas or populations during one or more seasons before reproducing for the first time. During these years of prospecting, they select a future breeding site, colony, or mate and improve various skills and their physical condition to meet the requirements of reproduction. One precondition of successful reproduction is arrival in time on the breeding grounds. Here, we study the intricate links among the date of initial spring arrival, body mass, sex, and the age of first breeding in the common tern Sterna hirundo, a long-lived migratory colonial seabird. The study is based on a unique, individual-based, long-term dataset of sexed birds, marked with transponders, which allow recording their individual arrival, overall attendance, and clutch initiation remotely and automatically year by year over the entire lifetime at the natal colony site. We show that the seasonal date of initial arrival at the breeding grounds predicts the individual age at first reproduction, which mostly occurs years later. Late first-time arrivals remain delayed birds throughout subsequent years. Our findings reveal that timing of arrival at the site of reproduction and timing of reproduction itself are coherent parameters of individual quality, which are linked with the prospects of the breeding career and may have consequences for fitness.

Winter commingling of populations of migratory species can cause breeding range underpopulation

We build a model with large‐scale demographic consequences for migratory species. The model operates where four elements co‐occur, and we rely on empirical research using migratory birds to demonstrate them. First, breeding ranges have internal structure flowing from natal philopatry. Second, fecundity varies geographically. Third, populations of different breeding provenances commingle during winter. And fourth, a population‐limiting carrying capacity operates during winter. In the absence of breeding season population‐limitation, only the breeding population with maximum fecundity persists. Consequently, some potential breeding areas that offer suitable and productive habitat are bereft of breeding birds because of the interplay between the geographical fecundity gradient and the shared winter quarters. Where breeding season population‐limitation also plays a role for at least one population, one (or more) breeding population becomes permanently depressed, resulting in a density well below the carrying capacity of the productive breeding habitat that is occupied. In either case, not all populations fare equally well, despite net positive breeding season productivity. Changes in winter carrying capacity, for example habitat degradation in winter quarters, can lead to uneven effects on geographically defined breeding populations, even though there has been no change in the circumstances of the breeding range.

Eastward moult migration of non-breeding pink-footed geese (Anser brachyrhynchus) in Svalbard

Six adult male pink-footed geese ( Anser brachyrhynchus ), tagged with satellite transmitters, were tracked in Svalbard during the period of June–September in 2003 and 2004. The purpose of the study was to describe the movements and staging periods of individual geese during the post-breeding period to investigate a possible moult migration among pink-footed geese in Svalbard. All geese moved about 200 km east from their potential breeding (summering) areas in western Spitsbergen. The preferred moulting area was the island of Edgeøya, where four geese staged prior to a southward autumn migration. Five geese left potential breeding areas between 11 and 30 June, and remained for more than 25 days in eastern areas during most of July, which we interpret as the moult migration of either failed or non-breeders. Geese left moulting areas in mid-August, using an average of 1.4 staging areas before the autumn migration, suggesting that moult sites support pre-migration hyperphagia. Only one goose remained at the suspected breeding site from early June to early September. Mean monthly temperatures in the summering and moulting ranges of the geese were calculated from Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data. The mean June moult range temperature ( ? 0.9 ° C) was significantly lower than that of the summering ranges (4.6 ° C). The July mean moult range temperature did not differ significantly from that in June on the summering ranges. We contend that failed or non-breeding pink-footed geese move eastward in Svalbard to exploit the early stages of summer plant growth as a result of the delayed thaw compared with central and southern Spitsbergen.

Eastward moult migration of non-breeding pink-footed geese (Anser brachyrhynchus) in Svalbard

Six adult male pink-footed geese ( Anser brachyrhynchus ), tagged with satellite transmitters, were tracked in Svalbard during the period of June–September in 2003 and 2004. The purpose of the study was to describe the movements and staging periods of individual geese during the post-breeding period to investigate a possible moult migration among pink-footed geese in Svalbard. All geese moved about 200 km east from their potential breeding (summering) areas in western Spitsbergen. The preferred moulting area was the island of Edgeoya, where four geese staged prior to a southward autumn migration. Five geese left potential breeding areas between 11 and 30 June, and remained for more than 25 days in eastern areas during most of July, which we interpret as the moult migration of either failed or non-breeders. Geese left moulting areas in mid-August, using an average of 1.4 staging areas before the autumn migration, suggesting that moult sites support pre-migration hyperphagia. Only one goose remained at the suspected breeding site from early June to early September. Mean monthly temperatures in the summering and moulting ranges of the geese were calculated from Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data. The mean June moult range temperature ( ? 0.9 ° C) was significantly lower than that of the summering ranges (4.6 ° C). The July mean moult range temperature did not differ significantly from that in June on the summering ranges. We contend that failed or non-breeding pink-footed geese move eastward in Svalbard to exploit the early stages of summer plant growth as a result of the delayed thaw compared with central and southern Spitsbergen.

Status of grey seals (<i>Halichoerus grypus</i>) in Norway

During the period September-December in 2001-2003, ship based surveys of grey seal (Halichoerus grypus) pups, including tagging, counting and staging of pups, were conducted along the Norwegian coast. All known and other potential breeding areas were surveyed from Rogaland county in the south to Finnmark county in the north. Most of the breeding sites were surveyed only once, but some sites were surveyed 2-4 times. The investigations resulted in a total minimum estimate of 1,159 grey seal pups born in Norwegian waters. Nordland county was the most important breeding area where about 50% of the pups were born. Total population estimates were derived from the recorded number of pups born using a range of multipliers (4.0-4.7), based on observed annual growth rates of approximately 7-12% in other grey seal populations. This gave a total estimate of about 5,800-6,600 grey seals including pups in Norwegian waters. However, the total pup production was probably underestimated due to only one pup count in most of the breeding sites. Observed mean pup mortality was 1.1% during the breeding season along the Norwegian coast.