scholarly journals Standardised empirical dispersal kernels emphasise the pervasiveness of long-distance dispersal in European birds

2021 ◽  
Author(s):  
Guillermo Fandos ◽  
Matthew Talluto ◽  
Wolfgang Fiedler ◽  
Rob A Robinson ◽  
Kasper Thorup ◽  
...  
Keyword(s):  
Phylogenetic Signal ◽  
Bird Species ◽  
Life History Trait ◽  
Phenotypic Trait ◽  
Breeding Dispersal ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Breeding Bird ◽  
Heavy Tailed ◽  
Dispersal Kernels

Dispersal is a key life-history trait for most species and essential to ensure connectivity and gene flow between populations and facilitate population viability in variable environments. Despite the increasing importance of range shifts due to global change, dispersal has proved difficult to quantify, limiting empirical understanding of this phenotypic trait and wider synthesis. Here we aim to estimate and compare empirical dispersal kernels for European breeding birds considering average dispersal, natal (before first breeding) and breeding dispersal (between subsequent breeding attempts), and test whether different dispersal properties are phylogenetically conserved. We standardised and analysed data from an extensive volunteer-based bird ring-recoveries database in Europe (EURING) by accounting for biases related to different censoring thresholds in reporting between countries and to migratory movements. Then, we fitted four widely used probability density functions in a Bayesian framework to compare and provide the best statistical descriptions of the average, the natal and the breeding dispersal kernels for each bird species. The dispersal movements of the 234 European bird species analysed were statistically best explained by heavy-tailed kernels, meaning that while most individuals disperse over short distances, long-distance dispersal is a feature in almost all bird species. The overall phylogenetic signal in both median and long dispersal distances was low (Pagel lambda < 0.40), implying a high degree of taxonomic generality in our findings. As expected in birds, natal dispersal was 5 Km greater as an average than breeding dispersal for most species (88% species analysed). Our comprehensive analysis of empirical kernels indicates that long-distance dispersal is common among European breeding bird species and across life stages. The dispersal estimates offer a first guide to selecting appropriate dispersal kernels in range expansion studies and provide new avenues to improve our understanding of the mechanisms and rules underlying dispersal events.

scholarly journals Biphasic range expansions with short- and long-distance dispersal

2021 ◽  
Author(s):  
Benjamin R. Liu
Keyword(s):  
Invasive Species ◽  
Mathematical Models ◽  
Short Distance ◽  
Initial Phase ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Integrodifference Equation ◽  
Key Factor ◽  
Heavy Tailed ◽  
Dispersal Kernels

AbstractLong-distance dispersal (LDD) has long been recognized as a key factor in determining rates of spread in biological invasions. Two approaches for incorporating LDD in mathematical models of spread are mixed dispersal and heavy-tailed dispersal. In this paper, I analyze integrodifference equation (IDE) models with mixed-dispersal kernels and fat-tailed (a subset of the heavy-tailed class) dispersal kernels to study how short- and long-distance dispersal contribute to the spread of invasive species. I show that both approaches can lead to biphasic range expansions, where an invasion has two distinct phases of spread. In the initial phase of spread, the invasion is controlled by short-distance dispersal. Long-distance dispersal boosts the speed of spread during the ultimate phase, and can have significant effects even when the probability of LDD is vanishingly small. For fat-tailed kernels, I introduce a method of characterizing the “shoulder” of a dispersal kernel, which separates the peak and tail.

scholarly journals Influence of gut morphology on passive transport of freshwater bryozoans by waterfowl in Doñana (southwestern Spain)

2004 ◽  
Vol 82 (6) ◽  
pp. 835-840 ◽  
Author(s):  
Jordi Figuerola ◽  
Andy J Green ◽  
Katrina Black ◽  
Beth Okamura
Keyword(s):  
Aquatic Invertebrates ◽  
Bird Species ◽  
Passage Time ◽  
Passive Dispersal ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Active Dispersal ◽  
Intestine Length ◽  
Internal Transport

Waterbirds have been proposed as important vectors for the passive dispersal of those aquatic invertebrates and plants that lack a capacity for active dispersal between isolated water bodies. We analysed the frequency of internal transport of bryozoan propagules (statoblasts) by waterbirds in Doñana, Spain, by examining their presence in the intestines and ceca of dead birds and analysing the role of different aspects of gut characteristics in explaining variation in the presence/absence and abundance of statoblasts. Of the 228 samples examined, 7.9% presented intact statoblasts of Plumatella fungosa (Pallas, 1768), Plumatella emarginata Allman, 1844, and two unidentified Plumatella species. For a given bird species, individuals with heavier gizzards and shorter ceca had a lower incidence and abundance of statoblasts in the lower gut. Grit mass and intestine length were unrelated to the presence or abundance of statoblasts. Our results suggest that waterbirds frequently transport bryozoans on a local scale, with lighter gizzards and longer ceca favouring such transport. Lighter gizzards are likely to destroy fewer propagules before they reach the lower gut. Species and individuals with longer ceca are particularly good candidates for long-distance dispersal of bryozoans, given the longer passage time of propagules that enter the ceca.

scholarly journals Diversity and structure of avian communities in extensive lowland pine forests in relation to the distance from the forest edge

2018 ◽  
Vol 26 (3) ◽  
pp. 206-212
Author(s):  
G. Kopij
Keyword(s):  
Edge Effect ◽  
Diversity Index ◽  
Bird Species ◽  
Feeding Guilds ◽  
Line Transect ◽  
Avian Communities ◽  
Long Distance ◽  
Breeding Bird ◽  
Area Effect ◽  
Field Edge

Most studies on edge effect are related to the forest-field edge, i.e. to the ecotone. However, there is a lack of studies attempting to investigate the effect of the distance from the forest/field edge on the avian communities in large continuous forests. The purpose of this study was to investigate this issue. The study area comprised a continuous coniferous forest, the so called Niemodlin Forest, situated in Opole Silesia, SW Poland. The line transect method has been employed in this study. In total, 54 breeding bird species were recorded. On particular 0.5 km section, the numbers varied from 34 to 48. Both the number of species and number of breeding pairs only slightly decreased with the distance from the forest/field edge. Overall, the differences between the mean densities of breeding species on 10 sections were not statistically significant. The Chaffinch Fringilla coelebs was by far the most numerous bird species, recorded as eudominant in 164 out of 165 sections. The Chiffchaff Phylloscopus collybita, Willow Warbler Phyloscopus trochilus and Blackap Sylvia atricapilla were dominants in all 10 sections, while the Blackbird Turdus merula dominated in nine (90%) and the Robin Erithacus rubecula in eight (80%) sections. The communal dominance slightly increased, but the number of dominant species and Pielou’s Evenness Index remained stable with the increase of the distance from the forest/field edge. While Shannon’s Diversity Index remained constant, Simpson’s Diversity Index decreased markedly with the increase in distance from the forest/field edge. The proportion of long-distance migrants slightly decreased, while that of short-distance migrants and residents remained constant with the increase in the distance from the forest/field edge. Strikingly, no such changes in the proportion of all feeding guilds were shown. More than half of all breeding bird species show a negative correlation between population density and the distance from the forest/field edge. The dominance of some species decreased with the increase of the distance from the forest/field edge: Hawfinch Coccothraustes coccothraustes, Starling Sturnus vulgaris, Blue Tit Parusa caeruleus, Raven Corvus corax, Wren Troglodytes troglodytes, Wood Pigeon Columba palumbus, and Wood Lark Lullula arborea. With the exception of the Yellowhammer Emberiza citrinella, the clearcuts in this study, not only failed to increase, but most probably caused a decrease in the number of both species and individuals. It is because clearing not only creates edges, but also causes loss of forest habitat and often results in forest fragmentation. Edge and area effect may in fact interact, in such way that the edge effect may drive out the area effect, causing the increase.

scholarly journals Evidence of avian-mediated long distance dispersal in American tardigrades

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5035 ◽  
Author(s):  
Matthew J. Mogle ◽  
Scott A. Kimball ◽  
William R. Miller ◽  
Richard D. McKown
Keyword(s):  
Bird Species ◽  
Distribution Patterns ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Neotropical Migrant ◽  
Grus Canadensis ◽  
Sandhill Crane ◽  
Migrant Birds ◽  
North And South

Terrestrial tardigrades, commonly known as “water bears”, are part of a phylum of microscopic, aquatic invertebrates famous for cryptobiosis and space travel, but little is known about their modes of dispersal on Earth. Wind is assumed, but not truly demonstrated, to be the major method of global dispersal. Yet, some water bear distribution patterns cannot be explained by patterns of prevailing winds. Mammals and birds have been proposed as potential animal vectors. Importantly, most nearctic-neotropical migrant birds move north and south, with many crossing the equator, whereas prevailing winds move west to east or east to west but do not cross the equator. When multiplied by billions of birds over tens of millions of years, if the ectozoochory of tardigrades by birds is true then both regional and intercontinental patterns can be better explained. To test for the potential role of birds in tardigrade dispersal, the nests of 10 species for birds were examined. Seventy percent of nests were positive for tardigrades, demonstrating that some birds are in a position for transference. The carcasses of eight birds (six species) found dead from window strikes and a Sandhill Crane (Grus canadensis) found dead during routine surveys were also examined. Of the birds examined, 66% yielded tardigrades from two classes, three orders, and five species, including juveniles, adults, and eggs, suggesting that many bird species are potential vectors for many species of tardigrades. Our data support the hypothesis of avian-mediated long distance dispersal of tardigrades and provide evidence that further investigation is warranted.

scholarly journals Structure of avian communities in lowland coniferous forests in Opole Silesia (SSW Poland)

2017 ◽  
Vol 66 (2) ◽  
pp. 149-161
Author(s):  
Grzegorz Kopij
Keyword(s):  
Diversity Index ◽  
Bird Species ◽  
Total Surface Area ◽  
Coniferous Forests ◽  
Line Transect ◽  
Managed Forest ◽  
Feeding Guild ◽  
Long Distance ◽  
Breeding Bird ◽  
Shannon’S Diversity Index

Abstract In Poland, forests comprise 31% of the total surface area, while the lowland coniferous forests comprise 51% of 94 000 km2 afforested areas. The line transect method was employed in 2002 and 2004 to estimate population densities and dominance of all bird species breeding in a selected fragment of such forest (eight transects with 165 sections and 77.7 km in total length). In total, 54 breeding bird species were recorded. The numbers varied between 37 and 44 on the particular transect. The number of breeding pairs per 10 ha varied on each transect from 41.0 to 93.6 (x=64.8; SD=102.22). Shannon’s diversity index varied between 1.2 and 1.4 on particular transects, while Simpson’s diversity index varied between 0.7 and 0.9. Also Pieleau’s evenness index varied slightly between 0.05 and 0.07. In overall, the differences between densities of breeding species on 8 transects were not statistically significant. The Chaffinch Fringilla coelebs was by far the most numerous bird species, recorded as eudominant in all eight transects and present in all 165 sections. The second to the Chaffinch was the Chiffchaff Phylloscopus collybita; also recorded in all sections and as a dominant in all transects. Three other species, namely the Blackbird Turdus merula, Willow Warbler Phylloscopus trochilus and Blackcap Sylvia atricapilla were recorded each one in more than 90% sections (N=165), and on particular transects their dominance varied between 4 and 11%. Residents comprised 57.5% of all breeding pairs. Short-distance migrants were almost twice more common than long-distance migrants. Insectivores were by far the most numerous feeding guild represented 88.9% of all breeding pairs. Overall density, cumulative dominance, diversity and evenness were unexpectedly very similar in this study (managed forest) and in natural primeval lowland coniferous forests of Białowieża.

scholarly journals Examining the genetic influences of migratory status on island colonisation by naturally and recently established populations of a bird species

2020 ◽  
Author(s):  
Daisuke Aoki ◽  
Shin Matsui ◽  
Mari Esashi ◽  
Isao Nishiumi ◽  
Junco Nagata ◽  
...  
Keyword(s):  
Population Genetics ◽  
Bird Species ◽  
Seasonal Migration ◽  
Long Distance Dispersal ◽  
Migratory Behaviour ◽  
Normal Range ◽  
Long Distance ◽  
Island Populations ◽  
Population Establishment ◽  
Migratory Status

AbstractSeasonal migration influences long-distance dispersal and population establishment, which are the two important steps for successful island colonisation. Migratory behaviour facilitates the long-distance dispersal of individuals through frequent appearance outside a species’ normal range, while sedentary behaviour may lead to dispersal by post-fledgling flocks whose accidental immigration provide sufficient propagules for population establishment. We assessed the relative contributions of migratory and sedentary populations to island colonisation, by performing population genetics analyses on four recently and naturally established island populations of the Bull-headed Shrike (Lanius bucephlaus). Analyses using 15 microsatellite loci inferred colonisation by flocks of immigrants from possibly sedentary populations for all the islands studied. On one island, we found a correlation between wing length and the genetic probability of assignment to a migratory population, indicating a genetic contribution by migratory immigrants. Yet migratory immigrants to this island were inferred to be only two over eight years of sampling. We imply that sedentary populations were successful island colonists because more immigrants can be provided through their post-fledgling dispersal than through solitary migration. This is the first attempt to examine, using population genetics, influence of migratory behaviour on island colonisation thereby, bridging the gap between population ecology and island biogeography.

Continuous population declines for specialist farmland birds 1987-2014 in Denmark indicates no halt in biodiversity loss in agricultural habitats

2017 ◽  
Vol 28 (2) ◽  
pp. 278-292 ◽  
Author(s):  
HENNING HELDBJERG ◽  
PETER SUNDE ◽  
ANTHONY DAVID FOX
Keyword(s):  
Bird Species ◽  
Biodiversity Loss ◽  
Population Declines ◽  
Farmland Birds ◽  
Long Distance ◽  
Breeding Bird ◽  
Specific Analysis ◽  
Bird Monitoring ◽  
Species Specific ◽  
Abundance And Distribution

SummaryThe 2020 EU biodiversity strategy aims to halt the loss of biodiversity and ecosystem services, but this requires effective monitoring to determine whether these aims are achieved. Common bird monitoring continuously assesses changes in the avian community, providing a powerful tool for monitoring temporal changes in the abundance and distribution of these upper trophic level consumers. Two-thirds of Denmark’s land area is intensively farmed, so agricultural habitats make a major contribution to Danish biodiversity. We looked for changes in abundance amongst farmland birds in Denmark during 1987–2014 to test for reductions in declines and to predict whether the 2020-target can be expected to be achieved. Sixteen specialist farmland species were those showing the most rapid declines amongst 102 common breeding species in Denmark. Of these, those species nesting on the ground showed significant long-term declines, which was not the case for those that nest elsewhere, i.e. in hedgerows, trees and buildings. There was no evidence to suggest that these trends were attributable to widespread declines in long-distance migrant species (as reported elsewhere), which may be affected by conditions at other times in the annual cycle. We therefore conclude that continued declines in specialist farmland breeding bird species are due to contemporary agricultural changes within Denmark and urge habitat- and species-specific analysis to identify the core causes of these changes and halt the declines.

scholarly journals Human-mediated dispersal of seeds over long distances

2008 ◽  
Vol 276 (1656) ◽  
pp. 523-532 ◽  
Author(s):  
Matthias C Wichmann ◽  
Matt J Alexander ◽  
Merel B Soons ◽  
Stephen Galsworthy ◽  
Laura Dunne ◽  
...  
Keyword(s):  
Mechanistic Models ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Mechanistic Modelling ◽  
Wide Range ◽  
Primary Vector ◽  
Dispersal Events ◽  
Dispersal Kernels ◽  
Vector Wind ◽  
Primary Dispersal

Human activities have fundamental impacts on the distribution of species through altered land use, but also directly by dispersal of propagules. Rare long-distance dispersal events have a disproportionate importance for the spread of species including invasions. While it is widely accepted that humans may act as vectors of long-distance dispersal, there are few studies that quantify this process. We studied in detail a mechanism of human-mediated dispersal (HMD). For two plant species we measured, over a wide range of distances, how many seeds are carried by humans on shoes. While over half of the seeds fell off within 5 m, seeds were regularly still attached to shoes after 5 km. Semi-mechanistic models were fitted, and these suggested that long-distance dispersal on shoes is facilitated by decreasing seed detachment probability with distance. Mechanistic modelling showed that the primary vector, wind, was less important as an agent of long-distance dispersal, dispersing seeds less than 250 m. Full dispersal kernels were derived by combining the models for primary dispersal by wind and secondary dispersal by humans. These suggest that walking humans can disperse seeds to very long distances, up to at least 10 km, and provide some of the first quantified dispersal kernels for HMD.

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