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1.
Malcolm D. Burgess Tom Finch Jennifer A. Border Joan Castello Greg Conway Martin Ketcher Mark Lawrence Christopher J. Orsman Judit Mateos Amanada Proud Stephen Westerberg Tina Wiffen Ian G. Henderson 《Ibis》2020,162(4):1292-1302
Determining the links between breeding populations and the pressures, threats and conditions they experience presents a challenge for the conservation of migratory birds which can use multiple sites separated by hundreds to thousands of kilometres. Furthermore, migratory connectivity – the connections made by migrating individuals between networks of breeding and non-breeding sites – has important implications for population dynamics. The Whinchat Saxicola rubetra is declining across its range, and tracking data from a single African non-breeding site implies high migratory spread. We used geolocators to describe the migration routes and non-breeding areas of 20 Whinchats from three British breeding populations. As expected, migratory spread was high, with birds from the three populations overlapping across a wide area of West Africa. On average, in non-breeding areas, British breeding Whinchats were located 652 km apart from one another, with some likely to share non-breeding areas with individuals from breeding populations as far east as Russia. Four males made a direct non-breeding season movement to a second, more westerly, non-breeding location in January. Autumn migration was through Iberia and around the western edge of the Sahara Desert, whereas spring migration was more direct, indicating an anticlockwise loop migration. Weak migratory connectivity implies that Whinchat populations are somewhat buffered against local changes in non-breeding conditions. If non-breeding season processes have played a role in the species’ decline, then large-scale drivers are likely to be the cause, although processes operating on migration, or interactions between breeding and non-breeding processes, cannot be ruled out. 相似文献
2.
Catriona A. Morrison Stephen R. Baillie Jacquie A. Clark Alison Johnston David I. Leech Robert A. Robinson 《Ibis》2015,157(2):340-350
Higher temperatures resulting from climate change have led to predictions that the duration of the breeding season of many temperate bird species may be changing. However, the extent to which breeding seasons can be altered will also depend on the degree of flexibility in processes occurring at other points in the annual cycle. In particular, plasticity in the timing of post‐breeding moult (PBM) could facilitate changes in the timing of key events throughout the annual cycle, but little is known about the level of within‐ and between‐species plasticity in PBM. As part of the British Trust for Ornithology (BTO) Ringing Scheme, many ringers routinely record moult scores of flight feathers, and these can be used to provide information on the annual progression of PBM for a range of species. Here we use ringing data to investigate patterns of PBM in 15 passerines, as well as data from the BTO Nest Record Scheme to relate these differences to the timing of breeding of these species across the UK. We find considerable variation in both the mean start (19 May–29 July) and duration (66–111 days) of PBM between species, but find no evidence that species starting PBM later in the season complete it any faster. However, there is considerable within‐species variation in PBM, particularly for multi‐brooded species; PBM starts later and is completed in less time when the duration of the breeding season (difference between first and last nests) is longer. This implies that a later end to breeding can be compensated for by faster PBM, and that advances in breeding could lead to earlier and slower PBM. Our findings suggest that adaptation of PBM in response to climate‐mediated changes in the timing and duration of the breeding season is possible. However, the requirement to complete PBM prior to migration or the onset of winter might constrain the extent to which breeding seasons can lengthen, especially for later nesting species. 相似文献
3.
Silke Bauer Judy Shamoun‐Baranes Cecilia Nilsson Andrew Farnsworth Jeffrey F. Kelly Don R. Reynolds Adriaan M. Dokter Jennifer F. Krauel Lars B. Petterson Kyle G. Horton Jason W. Chapman 《Ecography》2019,42(5):861-875
Many migratory species have experienced substantial declines that resulted from rapid and massive expansions of human structures and activities, habitat alterations and climate change. Migrants are also recognized as an integral component of biodiversity and provide a multitude of services and disservices that are relevant to human agriculture, economy and health. The plethora of recently published studies reflects the need for better fundamental knowledge on migrations and for better management of their ecological and human‐relevant effects. Yet, where are we in providing answers to fundamental questions and societal challenges? Engaging a broad network of researchers worldwide, we used a horizon‐scan approach to identify the most important challenges which need to be overcome in order to gain a fuller understanding of migration ecology, and which could be addressed using radar aeroecological and macroecological approaches. The top challenges include both long‐standing and novel topics, ranging from fundamental information on migration routes and phenology, orientation and navigation strategies, and the multitude of effects migrants may have on resident communities, to societal challenges, such as protecting or preventing migrant services and disservices, and the conservation of migrants in the face of environmental changes. We outline these challenges, identify the urgency of addressing them and the primary stakeholders – researchers, policy makers and practitioners, or funders of research. 相似文献
4.
曹翰;张文博;孙丰硕;田恒久;隋金玲 《四川动物》2015,34(5):756-758
2014年4-10月,利用焦点个体取样法与连续记录法对北京市野生动物救护繁育中心饲养的褐马鸡Crossoptilon mantchuricum繁殖期以及非繁殖期的行为时间分配和活动节律进行了研究。统计了不同性别与不同季节的行为时间分配差异。在繁殖期,雌性褐马鸡的取食时间大于雄性,而雄性褐马鸡的移动、警戒行为时间大于雌性。在非繁殖期,雌雄褐马鸡行为差异变小,但雄性褐马鸡的警戒行为仍然较多。 相似文献
5.
How individual birds schedule their movements and use different sites during the non‐breeding season are fundamental issues in avian migration ecology, and studies have often revealed strong seasonal variation in such strategies. Using geolocators we tracked Common Ringed Plovers Charadrius hiaticula from northern Norway to West Africa and back to assess whether there were differences in migratory speed, duration and stopover use between autumn and spring migration and whether birds used multiple sites during the non‐breeding season. Although the pace of migration was similar between autumn and spring, the length of flight bouts and duration of the preceding stopovers were positively correlated only in autumn. Four of five birds showed a marked southward movement in mid‐winter. 相似文献
6.
Antoine Grissot Isla M. Graham Lucy Quinn Vegard S. Bråthen Paul M. Thompson 《Ibis》2020,162(2):446-459
Seabirds are key marine top predator species that are often used as indicators of the environmental quality of the oceans. Their breeding phenology has been studied extensively, but their pelagic habits mean less is known about the phenology of other events during the non-breeding period. Here, we used miniaturized saltwater immersion light-based geolocators (GLS) to investigate moult phenology in individuals with known breeding histories in a population of Northern Fulmar Fulmarus glacialis in Orkney, Scotland. As seabirds spend more time on the water during moult, moulting periods can be identified from patterns of variation in the amount of time that birds are in contact with saltwater. Estimates of daily variation in this behaviour during the non-breeding period were based upon wet/dry sensors and then modelled to characterize the timing of the moult. Light-based geolocation provided information on the areas used by each individual during its moult period. Inter-individual variability in moult timing was investigated in relation to sex and breeding success in the previous summer. We found a sex difference in the location of the moult, but not in its timing. However, the timing of moult did differ between individuals that had succeeded or failed in their previous breeding attempt, with successful breeders moulting the latest. In contrast, the duration of moult did not depend on prior reproductive success, but there was evidence of inter-annual variation in moult duration. GLS studies have provided a step change in our understanding of the at-sea distribution of pelagic seabirds. Our work highlights how activity data from these devices can add value to such studies by identifying key phases of the annual cycle, and locations at these times, when seabirds may be at particular risk. Furthermore, our findings indicate that individual and inter-annual variation in breeding success may influence phenological patterns in other phases of the Northern Fulmar annual cycle. 相似文献
7.
Afro‐Palaearctic migrants are declining to a greater degree than other European species, suggesting that processes occurring in Africa or on migration may be driving these trends. Constraints on food availability on the wintering grounds may contribute to these declines but little is known about when and where these resource constraints may occur. Sufficient resources are particularly important prior to spring migration, when migrants must cross the Sahara Desert. We examined mass gain and departure phenology in a long‐distance Palaearctic passerine migrant to determine the degree to which pre‐migratory fattening occurs in their long‐term non‐breeding territories in the Guinea Savannah region of Africa. We monitored 75 Whinchats Saxicola rubetra for departure from their non‐breeding territories in one spring, and analysed mass data of 377 Whinchats collected over three non‐breeding seasons plus 141 migrating Whinchats caught in April over 8 years, all within the same few square kilometres of human‐modified Guinea Savannah in central Nigeria. Whinchats left their winter territories throughout April, with males departing on average 8 days earlier than females. However, there was no evidence that time of departure from territory was linked to age, body size or mass at capture. Whinchats departed their territories with a predicted mass of 16.8 ± 0.3 g, considerably less than the c. 24 g required for the average Whinchat to cross the Sahara directly. Comparing departure dates with arrival dates in southern Europe showed a discrepancy of at least 2 weeks, suggesting that many Whinchats spend considerable time on pre‐migratory fuelling outside their winter territory prior to crossing the Sahara. Overwintering birds gained mass slowly during February and March (0.03 g/day), and non‐territorial or migrating birds at a much higher rate in April (at least 0.23 g/day), with up to 20% of migrating Whinchats in April potentially having sufficient fuel loads to cross the Sahara directly from central Nigeria. Our results suggest that most Whinchats leave their winter territories to fatten up locally or, possibly, by staging further north, closer to the southern limit of the Sahara. Resource constraints are therefore likely to be particularly focused in West Africa during mid‐April and possibly at staging areas before the crossing of the Sahara Desert. 相似文献
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Juliet S. Lamb Scott G. Gilliland Jean-Pierre. L. Savard Pamela H. Loring Scott R. McWilliams Glenn H Olsen Jason E. Osenkowski Peter W. C. Paton Matthew C. Perry Timothy D. Bowman 《The Journal of wildlife management》2021,85(8):1628-1645
Sea ducks exhibit complex movement patterns throughout their annual cycle; most species use distinct molting and staging sites during migration and disjunct breeding and wintering sites. Although research on black scoters (Melanitta americana) has investigated movements and habitat selection during winter, little is known about their annual-cycle movements. We used satellite telemetry to identify individual variation in migratory routes and breeding areas for black scoters wintering along the Atlantic Coast, to assess migratory connectivity among wintering, staging, breeding, and molt sites, and to examine effects of breeding site attendance on movement patterns and phenology. Black scoters occupied wintering areas from Canadian Maritime provinces to the southeastern United States. Males used an average of 2.5 distinct winter areas compared to 1.1 areas for females, and within-winter movements averaged 1,256 km/individual. Individuals used an average of 2.1 staging sites during the 45-day pre-breeding migration period, and almost all were detected in the Gulf of St. Lawrence. Males spent less time at breeding sites and departed them earlier than females. During post-breeding migration, females took approximately 25 fewer days than males to migrate from breeding sites to molt and staging sites, and then wintering areas. Most individuals used molt sites in James and Hudson bays before migrating directly to coastal wintering sites, which took approximately 11 days and covered 1,524 km. Males tended to arrive at wintering areas 10 days earlier than females. Individuals wintering near one another did not breed closer together than expected by chance, suggesting weak spatial structuring of the Atlantic population. Females exhibited greater fidelity (4.5 km) to previously used breeding sites compared to males (60 km). A substantial number of birds bred west of Hudson Bay in the Barrenlands, suggesting this area is used more widely than believed previously. Hudson and James bays provided key habitat for black scoters that winter along the Atlantic Coast, with most individuals residing for >30% of their annual cycle in these bays. Relative to other species of sea duck along the Atlantic Coast, the Atlantic population of black scoter is more dispersed and mobile during winter but is more concentrated during migration. These results could have implications for future survey efforts designed to assess population trends of black scoters. © 2021 The Wildlife Society. 相似文献
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Studying sexual dimorphism facilitates better understanding of the general intersexual divergence of the same species and gives insights into the impact of selective forces on each sex. The sexual dimorphism in anuran external morphology or limb muscles has been well studied in reproductive context, but less so outside the breeding season. Herein, the intersexual differences in 12 external morphological characteristics, 11 forelimb and 12 hindlimb muscles of Hylarana guentheri during non-breeding season were investigated. We found that the males possessed significantly greater head width and tympanum diameter, while the females had significantly larger body size and head length; there was no sexual differences in the examined limb muscles, except for the mass of flexor carpi radialis. The larger body size means greater fertility for the females, and the longer head may be related to the allometry and reduce resource competition. For the males, the wider head is likely correlated with prey size and male–male competition, and also, the larger tympanum and heavier flexor carpi radialis probably aid the productive success. This study provides the comprehensive morphological accounts about the sexual differences of H. guentheri during non-breeding season, which will contribute to clarify the sex-specific resource allocation and reproductive strategies of anurans. 相似文献
12.
Stuart E. Newson Nick J. Moran Andy J. Musgrove James W. Pearce‐Higgins Simon Gillings Philip W. Atkinson Ryan Miller Mark J. Grantham Stephen R. Baillie 《Ibis》2016,158(3):481-495
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. 相似文献
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Lila Buckingham;Francis Daunt;Maria I. Bogdanova;Robert W. Furness;Sophie Bennett;James Duckworth;Ruth E. Dunn;Sarah Wanless;Michael P. Harris;David C. Jardine;Mark A. Newell;Robin M. Ward;Ewan D. Weston;Jonathan A. Green; 《Journal of avian biology》2023,2023(1-2):e03018
The non-breeding season presents significant energetic challenges to birds that breed in temperate or polar regions, with clear implications for population dynamics. In seabirds, the environmental conditions at non-breeding sites drive food availability and the energetic cost of regulatory processes, resulting in variation in diet, behaviour and energetics; however, very few studies have attempted to understand if and how these aspects vary between populations. We investigated whether non-breeding location influenced diet, behaviour and energetics in the common guillemot Uria aalge. We studied guillemots from four UK breeding colonies, two located on the west coast of Scotland and two on the east. We quantified non-breeding distribution, foraging behaviour and activity budgets of 39 individuals from July to March, using geolocation–immersion loggers and time-depth recorders, and used feather stable isotope signatures to infer diet during the post-breeding moult. We calculated energy expenditure and investigated whether the peak (an indicator of the potential vulnerability to marine threats) varied between colonies. Individuals were spatially segregated according to the coastline they breed on, with west coast guillemots distributed off the west coast of the UK and east coast guillemots distributed off the east coast. Diet and behaviour were more similar in guillemots that shared a breeding coastline than those that did not, as west coast guillemots foraged at a lower trophic level, spent less time diving and engaged in more pelagic foraging than east coast guillemots. However, energy expenditure was remarkably similar between colonies, peaking during late February/early March, indicating that, during our study period, there was high synchrony between colonies in the timing of potential vulnerability to marine threats. Therefore, any anthropogenic changes that result in decreased food availability or increased energy expenditure during late winter may have greater impacts on energy balance, with consequences for population dynamics. 相似文献
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Bird population density and their behaviour during non-breeding periods are determined mainly by meteorological conditions
which force birds to use alternative strategies — migration to areas with more advantageous conditions or adaptation to existing
conditions. During the 2002/03–2004/5 non-breeding seasons in the open habitats of the Kotlina Orawsko-Nowotarska valley (S
Poland) studies on population dynamics, behaviour and habitat use of great grey shrike were conducted. Results were grouped
into four meteorological periods (autumn, early winter, winter and early spring). Density changes were seen between subsequent
seasons (from 0.34 to 1.9 ind./10 km), as well as between meteorological periods (from 0.48 to 2.70 ind./10 km). Perching
was the most frequently observed behaviour. The foraging habitats used changed in frequency. In subsequent meteorological
periods a decrease of open habitats used was noted with a simultaneous increase in afforestations used. These changes did
not depend on lasting snow cover. Changes in vegetation type used during hunting were not observed. Great grey shrikes most
frequently used natural perches (trees, shrubs and high vegetation). 相似文献
17.
Jesús Rojo Mariano D. Serrano-Bravo Beatriz Lara Federico Fernández-González 《Plant biosystems》2019,153(1):98-107
Halo-nitrophilous scrubs are characterised by their floristic richness in species of the family Amaranthaceae (include Chenopodiaceae) and the Mediterranean saltbush (Atriplex halimus L.) is one of the most characteristic species in the Mediterranean region. Pollen from Amaranthaceae is the main cause of pollinosis at the end of summer and autumn. In this study, the floral phenology of the species Atriplex halimus L., was studied relating it to the atmospheric concentration of Amaranthaceae pollen with the aim to know if it can serve as an indicator of the maximum pollen concentrations. Observations of the male floral phenology of Atriplex halimus were performed over the course of three years in the central Iberian Peninsula (Spain) and the aerobiological pollen data of Amaranthaceae were obtained using a Hirst-type volumetric trap. The results demonstrated that the flowering period of Atriplex halimus closely coincided with the peak pollen levels. Besides, the prevailing movements of air masses in relation to the distribution and abundance of the halo-nitrophilous scrub during the flowering period of Atriplex halimus were studied using a back-trajectory analysis. The results showed that distinct predominant wind patterns led to differences in the quantity of pollen recorded during the pollen season and in the behaviour of the evolution of airborne pollen concentrations. 相似文献
18.
Adrià Descals Aleixandre Verger Gaofei Yin Iolanda Filella Yongshuo H. Fu Shilong Piao Ivan A. Janssens Josep Peñuelas 《Global Change Biology》2023,29(3):719-730
Climatic warming has lengthened the photosynthetically active season in recent decades, thus affecting the functioning and biogeochemistry of ecosystems, the global carbon cycle and climate. Temperature response of carbon uptake phenology varies spatially and temporally, even within species, and daily total intensity of radiation may play a role. We empirically modelled the thresholds of temperature and radiation under which daily carbon uptake is constrained in the temperate and cold regions of the Northern Hemisphere, which include temperate forests, boreal forests, alpine and tundra biomes. The two-dimensionality of the temperature-radiation constraint was reduced to one single variable, θ, which represents the angle in a polar coordinate system for the temperature-radiation observations during the start and end of the growing season. We found that radiation will constrain the trend towards longer growing seasons with future warming but differently during the start and end of season and depending on the biome type and region. We revealed that radiation is a major factor limiting photosynthetic activity that constrains the phenology response to temperature during the end-of-season. In contrast, the start of the carbon uptake is overall highly sensitive to temperature but not constrained by radiation at the hemispheric scale. This study thus revealed that while at the end-of-season the phenology response to warming is constrained at the hemispheric scale, at the start-of-season the advance of spring onset may continue, even if it is at a slower pace. 相似文献
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An international and interdisciplinary Radar Aeroecology Workshop was held at the National Weather Center on 5-6 March 2012 on the University of Oklahoma campus in Norman, OK, USA. The workshop brought together biologists, meteorologists, radar engineers and computer scientists from 22 institutions and four countries. A central motivation behind the Radar Aeroecology Workshop was to foster better communication and cross-disciplinary collaboration among a diverse spectrum of researchers, and promote a better understanding of the ecology of animals that move within and use the Earth's lower atmosphere (aerosphere). 相似文献