Warmer springs advance the breeding phenology of golden plovers Pluvialis apricaria and their prey (Tipulidae)

Most studies of climate-driven changes in avian breeding phenology have focused on temperate passerines, yet the consequences of such environmental change may be more deleterious for other avian taxa, such as arctic and sub-arctic waders (Charadrii). We therefore examine large-scale climatic correlates of the breeding phenology of one such species (golden plover Pluvialis apricaria), and the timing of emergence of their adult tipulid prey, to assess the potential for climate change to disrupt breeding performance. Golden plover first-laying dates were negatively correlated with both March and April temperature, the mean laying date of first clutches was additionally negatively correlated with March rainfall. The timing of final laying dates were negatively correlated with April temperature only. The timing of tipulid emergence was negatively correlated with May temperature. In combination with historical climatic data, these models suggest a 9-day advancement of golden plover first-laying dates occurred during the 1990s, although this remains within the range of natural variation for the twentieth century. The magnitudes of predicted changes in mean and final laying dates, and the timing of tipulid emergence, were smaller. Climate predictions for 2070-2099 suggest potential advances in first-laying dates by 25 days, whilst the timings of mean and final laying dates are predicted to change by 18 days and 13 days, and tipulid emergence by 12 days. Given the importance of adult tipulids to young golden plover chicks, these changes may result in a mismatch between the timing of first-laying dates and tipulid emergence, so reducing the success of early breeding attempts. Modelling suggests that these changes could reduce breeding success in a South Pennines population by about 11%.     

Habitat selection,diet and food availability of European Golden Plover Pluvialis apricaria chicks in Swedish Lapland

Fennoscandian alpine tundra habitats support large numbers of breeding waders, but relatively little is known about their breeding ecology despite the fact that this habitat is threatened by climate change. We studied habitat selection, diet and prey availability of European (Eurasian) Golden Plover Pluvialis apricaria chicks at the Vindelfjällen Nature Reserve, Ammarnäs, Sweden. Information from 22 chicks tracked using radio‐transmitters was analysed. By analysing 149 faecal samples, four main prey taxa were identified, Coleoptera (40%), Bibionidae (31%), Hymenoptera (13%) and Tipulidae (10%). We found that chicks switched from feeding on Tipulidae to feeding on Bibionidae as they grew, and that this switch coincided with a shift from the use of the habitat where Tipulidae were abundant (alpine meadow/heathland) to the use of the habitat were Bibionidae were abundant (Willow shrub). Although chicks track food availability to some extent, the link between prey availability and habitat use was not perfect, indicating that additional factors other than food abundance, such as shelter from predators, determine habitat selection. Bibionidae are an important prey for Golden Plover chicks as it is the only prey group that has a late summer flush in abundance, in contrast to the general decline of total arthropod biomass during the chick‐rearing period. However, Bibionidae imagoes only occurred in 2011 and were virtually absent in 2013, which relates to the species’ ecology with 2‐ to 5‐year cycles in mass occurrence. Extreme annual variation in an essential food source such as Bibionidae imagoes might have an important effect on the condition and survival of Golden Plover chicks, an important subject for future studies. The foraging conditions for Golden Plover chicks in Fennoscandia appear to be different to those in the UK, where the chicks rely mainly on a Tipulidae flush only.     

Conditions at the breeding grounds and migration strategy shape different moult patterns of two populations of Eurasian golden plover Pluvialis apricaria

Events in the life cycle of migrant birds are generally time‐constrained. Moult, together with breeding and migration, is the most energetically demanding annual cycle stages, but it is the only stage that can be scheduled at different times of the year. However, it is still not fully understood what factors determine this scheduling. We compare the timing of primary feather moult in relation to breeding and migration between two populations of Eurasian golden plover Pluvialis apricaria, the continental population breeding in Scandinavia and in N Russia that migrates to the Netherlands and southern Europe, and the Icelandic population that migrates mainly to Ireland and western UK. Moult was studied at the breeding grounds (N Sweden, N Russia, Iceland) and at stopover and wintering sites (S Sweden, the Netherlands). In both populations, primary moult overlapped with incubation and chick rearing, and females started on average 9 d later than males. Icelandic plovers overlapped moult with incubation to a larger extent and stayed in the breeding grounds until primary moult was completed. In contrast, continental birds only moulted the first 5–7 primaries at the breeding grounds and completed moult in stopover and wintering areas, such as S Sweden and the Netherlands. This overlap, although rare in birds, can be understood from an annual cycle perspective. Icelandic plovers presumably need to initiate moult early in the season to be able to complete it at the breeding grounds. The latter is not possible for continental plovers as their breeding season is much shorter due to a harsher climate. Additionally, for this population, moulting all the primaries at the stopover/wintering site is also not possible as too little time would remain to prepare for cold‐spell movements. We conclude that environmental conditions and migration strategy affect the annual scheduling of primary feather moult in the Eurasian golden plover.     

Climate change‐induced migration patterns and extinction risks of Theaceae species in China

Theaceae, an economically important angiosperm family, is widely distributed in tropical and subtropical forests in Asia. In China, Theaceae has particularly high abundances and endemism, comprising ~75% of the total genera and ~46% of the total species worldwide. Therefore, predicting the response of Theaceae species to climate change is vital. In this study, we collected distribution data for 200 wild Theaceae species in China, and predicted their distribution patterns under current and future climactic conditions by species distribution modeling (SDM). We revealed that Theaceae species richness is highest in southeastern China and on Hainan Island, reaching its highest value (137 species) in Fujian Province. According to the IUCN Red List criteria for assessing species threat levels under two dispersal assumptions (no dispersal and full dispersal), we evaluated the conservation status of all Theaceae species by calculating loss of suitable habitat under future climate scenarios. We predicted that nine additional species will become threatened due to climate change in the future; one species will be classified as critically endangered (CR), two as endangered (EN), and six as vulnerable (VU). Given their extinction risks associated with climate change, we recommended that these species be added to the Red List. Our investigation of migration patterns revealed regional differences in the number of emigrant, immigrant, and persistent species, indicating the need for targeted conservation strategies. Regions containing numerous emigrants are concentrated in Northern Taiwan and coastal regions of Zhejiang and Fujian provinces, while regions containing numerous immigrants include central Sichuan Province, the southeastern Tibet Autonomous Region, southwest Yunnan Province, northwest Sichuan Province, and the junction of Guangxi and Hunan provinces. Lastly, regions containing persistent species are widely distributed in southern China. Importantly, regions with high species turnover are located on the northern border of the entire Theaceae species distribution ranges owing to upwards migration; these regions are considered most sensitive to climate change and conservation planning should therefore be prioritized here. This study will contribute valuable information for reducing the negative impacts of climate change on Theaceae species, which will ultimately improve biodiversity conservation efficiency.     

Faster migration in autumn than in spring: seasonal migration patterns and non‐breeding distribution of Icelandic whimbrels Numenius phaeopus islandicus

Migration is fundamental in the life of many birds and entails significant energetic and time investments. Given the importance of arrival time in the breeding area and the relatively short period available to reproduce (particularly at high latitudes), it is expected that birds reduce spring migration duration to a greater extent than autumn migration, assuming that pressure to arrive into the wintering area might be relaxed. This has previously been shown for several avian groups, but recent evidence from four tracked Icelandic whimbrels Numenius phaeopus islandicus, a long distance migratory wader, suggests that this subspecies tends to migrate faster in autumn than in spring. Here, we 1) investigate differences in seasonal migration duration, migration speed and ground speed of whimbrels using 56 migrations from 19 individuals tracked with geolocators and 2) map the migration routes, wintering and stopover areas for this population. Tracking methods only provide temporal information on the migration period between departure and arrival. However, migration starts with the fuelling that takes place ahead of departure. Here we estimate the period of first fuelling using published fuel deposition rates and thus explore migration speed using tracking data. We found that migration duration was shorter in autumn than in spring. Migration speed was higher in autumn, with all individuals undertaking a direct flight to the wintering areas, while in spring most made a stopover. Wind patterns could drive whimbrels to stop in spring, but be more favourable during autumn migration and allow a direct flight. Additionally, the stopover might allow the appraisal of weather conditions closer to the breeding areas and/or improve body condition in order to arrive at the breeding sites with reserves.     

Post‐breeding movements of Wood Storks in Brazil and Argentina

Seasonal migration and the dispersal of juvenile and adult Wood Storks (Mycteria americana) after breeding have been documented in the United States, but little is known about the post‐breeding movements of Wood Storks in South America. Our objective was to identify the locations of post‐breeding areas used by Wood Storks banded as nestlings in breeding colonies in Brazil by analyzing banding data. During the period from 1984 to 2007, 2543 nestlings were banded at breeding colonies in three regions of Brazil, with most (94%) banded in the Pantanal wetland in west‐central Brazil. Seventeen bands were subsequently recovered, with most (14) recovered in southern Brazil and northern Argentina. The mean distance between banding and recovery sites was 1265 km. Our results suggest that Wood Stork movements from breeding areas in Brazil are, as also reported in the United States, in response to changing water levels. The rainy season begins at the end of the breeding season and, in apparent response to rising water levels, Wood Storks in our study moved to drier areas further south with shallower water where they can forage more efficiently. Because only a small percentage of the area where Wood Stork bands were recovered in our study is currently protected, measures are needed to prevent habitat destruction and preserve wetland habitats used by Wood Storks during the post‐breeding period in southern Brazil and Argentina.     

Influence of streamflow on spawning‐related movements of golden perch Macquaria ambigua in south‐eastern Australia

In this study, linkages were examined between movement and spawning behaviour for golden perch Macquaria ambigua in a lowland river by integrating acoustic telemetry and egg and larval drift sampling over 4 years. Movement was strongly seasonal, being most prevalent during the spawning season (spring to early summer), and occurred primarily downstream into the lower river reaches during elevated flows. A very strong association was found between the occurrence of spawning and long‐distance M. ambigua movement. The results also revealed that targeted environmental water allocation can promote movement and spawning of this species. By integrating multiple analytical approaches and focusing on key life‐history events, this study provides an improved picture of the life history and flow requirements of M. ambigua. The findings can help guide the development of effective environmental flow recommendations.     

Non‐breeding areas and timing of migration in relation to weather of Scottish‐breeding common sandpipers Actitis hypoleucos

The number of breeding common sandpipers has declined in Britain due to poorer return rates from non‐breeding areas. To investigate little known aspects of their annual cycle, breeding common sandpipers were fitted with geolocators to track their migrations and determine their non‐breeding areas. Ten tagged birds left Scotland on 9 July (median dates and durations are given throughout the abstract). Short‐term staging was carried out by some birds in England and Ireland, then for longer by most birds in Iberia before continuing to West Africa, arriving on 28 July. Six birds spent most of the non‐breeding season (October–February) on the coast of Guinea‐Bissau, suggesting that this is a key area. Single birds occurred in Sierra Leone, Guinea, the Canary Islands and western Sahara. The southward migration from Scotland took 17.5 d (range 1.5–24 d), excluding the initial fuelling period. The first northward movement from Africa was on 12 April. Staging occurred in either Morocco, Iberia or France. Arrival in Scotland was on 2 May. The northward migration took 16 d (range 13.5–20.5 d). The main migration strategy involved short‐ and medium‐range flights, using tail‐winds in most cases. Variation in strategy was associated with departure date; birds that left later staged for shorter durations. Coastal West Africa provides two major habitats for common sandpipers: mudflats associated with mangroves and rice fields. Although the area of mangrove has been depleted, the scale of loss has probably been insufficient to account for the decline in sandpiper numbers. Rice fields are expanding, providing feeding areas for water‐birds. Meteorological data during the migrations suggest that the weather during the southward migration is unlikely to contribute to a population decline but strong cross‐winds or head‐winds during the northward migration to the breeding grounds may do so.     

Across a migratory divide: divergent migration directions and non‐breeding grounds of Eurasian reed warblers revealed by geolocators and stable isotopes

Migratory divides represent narrow zones of overlap between parapatric populations with distinct migration directions and, consequently, expected divergent non‐breeding distributions. The composition of the mixed population at a migratory divide and the corresponding non‐breeding ranges remain, however, unknown for many Palaearctic‐African migrants. Here, we used light‐level geolocation to track migration direction and non‐breeding grounds of Eurasian reed warblers Acrocephalus scirpaceus from three breeding populations across the species’ migratory divide. Moreover, by using feathers grown at non‐breeding grounds, we quantified stable isotope composition for individuals with known southwestern (SW) and southeastern (SE) migration directions. On a larger sample per population, we then assessed the proportions of SW‐ and SE‐migrating phenotypes in each of the three populations. All tracked reed warblers from Germany and two thirds of the birds tagged from the Czech population headed initially SW. Nevertheless, about one third of the birds from the Czech site migrated towards SE. No tracking data have been obtained for the Bulgarian population. The initial migration direction determined by geolocators was a strong predictor of the non‐breeding region, with SW migrants staying in west Africa and SE migrants in central Africa. Feather δ³⁴S and δ¹⁵N values confirmed the predominance of SW migrants in the German population, the co‐occurrence of SW and SE migrants in the Czech population, and indicated a high (72%) proportion of SE migrants in the Bulgarian population. Thus, the combined approach of geolocator tracking and stable isotopic assignments provided clear evidence for the existence of a migratory divide in the southeast of central Europe and predicted non‐breeding range in central and central‐eastern Africa for the eastern population.     

Local and regional weather patterns influencing post‐breeding migration counts of soaring birds at the Strait of Gibraltar,Spain

Migration is a significant event in the annual cycle of many avian species. During migration birds face many challenges, including unfamiliar foraging and refuge habitats, resulting in a much higher rate of mortality during migration than during other seasons of the year. Weather may significantly affect a bird's decision to initiate migration, the course and pace of migration, and its survival during migration. Each of these influences may impact the counts of migrating birds at geographical convergence zones or bottlenecks. It is important to quantify the effect of short‐term weather on these counts to appropriately interpret and use such counts in other analyses. To this end, we aim to assess the effects of local and regional weather conditions on the migration counts of soaring birds at the Strait of Gibraltar during post‐breeding migration. We used information‐theoretic approaches to analyse the influence of local weather and weather in northern Spain on the migration counts of five soaring bird species from two count sites near the Strait of Gibraltar. Migration counts were higher on days with local northerly and westerly winds, often following a day of easterly winds, on days with local high pressure systems, and often following a day of lower pressure. Weather conditions in northern Spain influenced migration counts at the Strait of Gibraltar, but the effects were much weaker than local weather conditions. We confirm that short‐term weather conditions, locally and regionally, can influence migration counts and should thus be considered when these counts are used in other analyses.     

Role of breeding and natal movements in lifetime dispersal of a forest‐dwelling rodent

The lifetime movements of an individual determine the gene flow and invasion potential of the species. However, sex dependence of dispersal and selective pressures driving dispersal have gained much more attention than dispersal at different life and age stages. Natal dispersal is more common than dispersal between breeding attempts, but breeding dispersal may be promoted by resource availability and competition. Here, we utilize mark–recapture data on the nest‐box population of Siberian flying squirrels to analyze lifetime dispersal patterns. Natal dispersal means the distance between the natal nest and the nest used the following year, whereas breeding movements refer to the nest site changes between breeding attempts. The movement distances observed here were comparable to distances reported earlier from radio‐telemetry studies. Breeding movements did not contribute to lifetime dispersal distance and were not related to variation in food abundance or habitat patch size. Breeding movements of males were negatively, albeit not strongly, related to male population size. In females, breeding movement activity was low and was not related to previous breeding success or to competition between females for territories. Natal philopatry was linked to apparent death of a mother; that is, we did not find evidence for mothers bequeathing territories for offspring, like observed in some other rodent species. Our results give an example of a species in which breeding movements are not driven by environmental variability or nest site quality. Different evolutionary forces often operate in natal and breeding movements, and our study supports the view that juveniles are responsible for redistributing individuals within and between populations. This emphasizes the importance of knowledge on natal dispersal, if we want to understand consequences of movement ecology of the species at the population level.     

Discovering the migration and non‐breeding areas of sand martins and house martins breeding in the Pannonian basin (central‐eastern Europe)

The central‐eastern European populations of sand martin and house martin have declined in the last decades. The drivers for this decline cannot be identified as long as the whereabouts of these long distance migrants remain unknown outside the breeding season. Ringing recoveries of sand martins from central‐eastern Europe are widely scattered in the Mediterranean basin and in Africa, suggesting various migration routes and a broad non‐breeding range. The European populations of house martins are assumed to be longitudinally separated across their non‐breeding range and thus narrow population‐specific non‐breeding areas are expected. By using geolocators, we identified for the first time, the migration routes and non‐breeding areas of sand martins (n = 4) and house martins (n = 5) breeding in central‐eastern Europe. In autumn, the Carpathian Bend and northern parts of the Balkan Peninsula serve as important pre‐migration areas for both species. All individuals crossed the Mediterranean Sea from Greece to Libya. Sand martins spent the non‐breeding season in northern Cameroon and the Lake Chad Basin, within less than a 700 km radius, while house martins were widely scattered in three distinct regions in central, eastern, and southern Africa. Thus, for both species, the expected strength of migratory connectivity could not be confirmed. House martins, but not sand martins, migrated about twice as fast in spring compared to autumn. The spring migration started with a net average speed of > 400 km d^–1 for sand martins, and > 800 km d^–1 for house martins. However, both species used several stopover sites for 0.5–4 d and were stationary for nearly half of their spring migration. Arrival at breeding grounds was mainly related to departure from the last sub‐Saharan non‐breeding site rather than distance, route, or stopovers. We assume a strong carry‐over effect on timing in spring.     

Quantifying non‐breeding season occupancy patterns and the timing and drivers of autumn migration for a migratory songbird using Doppler radar

For seasonal migrants, non‐breeding regions can play different roles in the ecology of their annual cycles: as stopover habitat, overwintering habitat, or as a combination in which some individuals stop‐over and others over‐winter. Such functional variations can lead to variation in occupancy dynamics and migration phenology to these different regions. In this study, we used data from archived Doppler weather surveillance radar to compare site‐occupancy and movement dynamics of a migratory songbird (tree swallow Tachycineta bicolor) between two non‐breeding areas: southeastern Louisiana and central peninsular Florida, USA. Specifically, in each area, we 1) quantified long‐term (1996–2012) non‐breeding season occupancy dynamics, 2) quantified variation in timing of autumn migration, and 3) tested which climate variables along their respective flyways were best correlated with variation in dates of arrival. Additionally, we cross‐validated the dynamics from archived radar with data from eBird, a large‐scale citizen science database that provides an independent measure of avian occupancy. We found strong and significant correlations between radar‐estimated and eBird‐estimated occupancy dynamics in both Louisiana and Florida. Long‐term Louisiana occupancy dynamics conformed to our hypothesis that this region acts as a combined stopover and overwintering region whereas Florida occupancy dynamics were akin to a traditional winter region. Arrival to Louisiana during the study period was much earlier and took place over a much shorter arrival window than did arrival to Florida, which showed much more gradual arrival over the course of several months. At both sites, annual variation in mean arrival date was best explained by the amount of precipitation along the lower portions of their respective migration flyways.     

Geolocator tagging reveals Pacific migration of Red‐necked Phalarope Phalaropus lobatus breeding in Scotland

The migration route of Red‐necked Phalarope populations breeding on North Atlantic islands has been subject to considerable speculation. Geolocator tags were fitted to nine Red‐necked Phalaropes breeding in northern Scotland to assess whether they migrated to Palaearctic or Nearctic wintering grounds. Of four birds known to return, two had retained their tags, of which one was recaptured. This male Phalarope left Shetland on 1 August 2012 and crossed the Atlantic Ocean to the Labrador Sea off eastern Canada in 6 days, then moved south to reach Florida during September, crossed the Gulf of Mexico into the Pacific Ocean and reached an area between the Galapagos Islands and the South American coast by mid‐October, where it remained until the end of April, returning by a similar route until the tag battery failed as the bird was crossing the Atlantic Ocean. The total migration of 22 000 km is approximately 60% longer than the previously assumed route to the western part of the Arabian Sea, and this first evidence of migration of a European breeding bird to the Pacific Ocean also helps to indicate the possible migratory route of the large autumn movements of Red‐necked Phalaropes down the east coast of North America.     

Sex‐specific patterns of fuelling and pre‐breeding body moult of Little Stints Calidris minuta in South Africa

The timing and duration of each stage of the life of a long‐distance migrant bird are constrained by time and resources. If the parental roles of males and females differ, the timing of other life stages, such as moult or pre‐migratory fuelling, may also differ between the sexes. Little is known about sexual differences for species with weak sexual dimorphism, but DNA‐sexing enables fresh insights. The Little Stint Calidris minuta is a monomorphic long‐distance migrant wader breeding in the Arctic tundra. Males compete for territories and perform elaborate aerial displays. Females produce two clutches a season. Each sex may be a bigamist and incubate one nest a season, each with a different partner. We expect that these differences in breeding behaviour entail different preparations for breeding by males and females, so we aimed to determine whether Little Stints showed any sex differences in their strategies for pre‐breeding moult and pre‐migratory fuelling at their non‐breeding grounds in South Africa. We used body moult records, wing length and body mass of 241 DNA‐sexed Little Stints that we caught and ringed between 27 January and 29 April in 2008–2018 at two neighbouring wetlands in North West Province, South Africa. For each individual we assessed the percentage of breeding plumage on its upperparts and took blood samples for DNA‐sexing. We calculated an adjusted Body Moult Index and an adjusted Wing Coverts Moult Index, then used the Underhill–Zucchini moult model to estimate the start dates and the rate of body moult in males and females. We estimated the changes in the sex ratio of the local population during their stay in South Africa, and also estimated the timing and rate of pre‐migratory fuelling and the potential flight ranges for males and females. The males started body moult on average on 7 February and the females on 12 February, but the sexes did not differ in their timing of wing covert moult, which started on average on 10 February. In January to mid‐February, males constituted c. 57% of the population, but their proportion declined afterwards, indicating an earlier departure than females. We estimated that both sexes began pre‐migratory fuelling on average on 15 March. The sexes did not differ in fuelling rate, but most females stayed at the non‐breeding site longer than the males, and thus accumulated more fuel and had longer potential flight ranges. These patterns of moult and fuelling suggest sex differences in preparations for breeding. We suggest that the males depart from South Africa earlier but with smaller fuel loads than the females to establish breeding territories before the females arrive. We conclude that for each sex the observed trade‐offs between fuelling and moult at the non‐breeding grounds are precursors to different migration strategies, which in turn are adaptations for their different roles in reproductive behaviour.     

Long‐term changes in the migration phenology of UK breeding birds detected by large‐scale citizen science recording schemes

The timing of migration is one of the key life‐history parameters of migratory birds. It is expected to be under strong selection, to be sensitive to changing environmental conditions and to have implications for population dynamics. However, most phenological studies do not describe arrival and departure phenologies for a species in a way that is robust to potential biases, or that can be clearly related to breeding populations. This hampers our ability to understand more fully how climate change may affect species’ migratory strategies, their life histories and ultimately their population dynamics. Using generalized additive models (GAMs) and extensive large‐scale data collected in the UK over a 40‐year period, we present standardized measures of migration phenology for common migratory birds, and examine how the phenology of bird migration has changed in the UK since the 1960s. Arrival dates for 11 of 14 common migrants became significantly earlier, with six species advancing their arrival by more than 10 days. These comprised two species, Blackcap Sylvia atricapilla and Chiffchaff Phylloscopus collybita, which winter closest to Britain in southern Europe and the arid northern zone of Africa, Common Redstart Phoenicurus phoenicurus, which winters in the arid zone, and three hirundines (Sand Martin Riparia riparia, House Martin Delichon urbicum and Barn Swallow Hirundo rustica), which winter in different parts of Africa. Concurrently, departure dates became significantly later for four of the 14 species and included species that winter in southern Europe (Blackcap and Chiffchaff) and in humid zones of Africa (Garden Warbler Sylvia borin and Whinchat Saxicola rubetra). Common Swift Apus apus was the exception in departing significantly earlier. The net result of earlier arrival and later departure for most species was that length of stay has become significantly longer for nine of the 14 species. Species that have advanced their timing of arrival showed the most positive trends in abundance, in accordance with previous studies. Related in part to earlier arrival and the relationship above, we also show that species extending their stay in Great Britain have shown the most positive trends. Further applications of our modelling approach will provide opportunities for more robust tests of relationships between phenological change and population dynamics than have been possible previously.     

The cost of migratory prey: seasonal changes in semi‐domestic reindeer distribution influences breeding success of Eurasian lynx in northern Norway

Migratory prey is a widespread phenomenon that has implications for predator–prey interactions. By creating large temporal variation in resource availability between seasons it becomes challenging for carnivores to secure a regular year‐round supply of food. Some predators may respond by following their migratory prey, however, most predators are sedentary and experience strong seasonal variation in resource availability. Increased predation on alternative prey may dampen such seasonal resource fluctuations, but reduced reproduction rates in predators is a predicted consequence of migratory primary prey behavior that has received little empirical attention. We used data from 23 GPS collared Eurasian lynx Lynx lynx monitored during 2007–2013 in northern Norway, to examine how spatio‐temporal variation in the migratory behavior of semi‐domestic reindeer Rangifer tarandus influences lynx spatial organization and reproductive success using estimates of seasonal home range overlap and breeding success. We found that lynx of both sexes maintained seasonally stable home ranges and exhibited site fidelity across years, independent of whether they had access to reindeer throughout the year or experienced a scarcity of reindeer in winter due to migration. However, lynx without access to reindeer in winter showed a decreased probability of reproducing and a tendency for lowered kitten survival into their first winter, when compared to female lynx with reindeer available year around. This supports the hypothesis that sedentary predators experience demographic costs in systems with migratory primary prey. Changes in the migratory behavior of ungulates, including disrupted migrations, is therefore likely to have bottom–up effects on the population dynamics of sedentary predators as well as the previously documented consequences for ungulate population dynamics.     

Variation in thermal niche of a declining river‐breeding frog: From counter‐gradient responses to population distribution patterns

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