scholarly journals Combined effects of migration distance, foraging method vegetation density, and population density on wing shapes of boreal songbirds

2018 ◽  
Author(s):  
Flavie Noreau ◽  
André Desrochers
Keyword(s):  
Population Density ◽  
Interspecific Variation ◽  
Breeding Population ◽  
Wing Shape ◽  
Habitat Isolation ◽  
Vegetation Density ◽  
Long Distance ◽  
Migration Distance ◽  
Interspecific Differences ◽  
Foraging Method

AbstractIn birds, migration distance is known to influence morphological attributes that influence flight performance, especially wing shape. However, wing shape is under the likely influence of less documented factors such as foraging method, vegetation density and isolation of individuals and populations. To better understand factors leading to interspecific differences in wing shape, we measured the pointedness of wings (Kipp’s distance) of 1017 live birds of 22 species in an eastern Canadian boreal forest. We modeled wing pointedness as a function of migration distances from eBird records, foraging, habitat, and population density data fromBirds of North Americamonographs. Long-distance migrants and species living in low-density vegetation had more pointed wings than shorter-distance migrants and dense-vegetation dwellers, in accordance to our predictions. After accounting for vegetation density and migration distance, we found no link between the extent of aerial foraging or mean breeding population density, an indicator of isolation, and wing pointedness. Those results are consistent with a tradeoff between sustained flight efficiency and maneuverability, but suggest that interspecific variation in wing shape due specifically to foraging method or habitat isolation is nonexistent or obscured by other factors.

scholarly journals Brain regions associated with visual cues are important for bird migration

2015 ◽  
Vol 11 (11) ◽  
pp. 20150678 ◽  
Author(s):  
Orsolya Vincze ◽  
Csongor I. Vágási ◽  
Péter L. Pap ◽  
Gergely Osváth ◽  
Anders Pape Møller
Keyword(s):  
Visual Cues ◽  
Optic Lobe ◽  
Brain Size ◽  
Relative Size ◽  
Bird Species ◽  
Interspecific Variation ◽  
Brain Regions ◽  
Long Distance ◽  
Migration Distance ◽  
Whole Brain

Long-distance migratory birds have relatively smaller brains than short-distance migrants or residents. Here, we test whether reduction in brain size with migration distance can be generalized across the different brain regions suggested to play key roles in orientation during migration. Based on 152 bird species, belonging to 61 avian families from six continents, we show that the sizes of both the telencephalon and the whole brain decrease, and the relative size of the optic lobe increases, while cerebellum size does not change with increasing migration distance. Body mass, whole brain size, optic lobe size and wing aspect ratio together account for a remarkable 46% of interspecific variation in average migration distance across bird species. These results indicate that visual acuity might be a primary neural adaptation to the ecological challenge of migration.

scholarly journals Body Condition and Survival of Vagrant Long-billed Murrelets, Brachyramphus perdix, in North America

2012 ◽  
Vol 126 (1) ◽  
pp. 6 ◽  
Author(s):  
Spencer G. Sealy ◽  
Harry R. Carter
Keyword(s):  
North America ◽  
Body Condition ◽  
West Coast ◽  
Atlantic Coast ◽  
Breeding Population ◽  
Adult Males ◽  
Long Distance ◽  
The West ◽  
Stopover Sites ◽  
America South

From 1979 through 2009, 81 records of long-distance vagrancy in the Long-billed Murrelet (Brachyramphus perdix) in North America south of Alaska were examined to assess body condition and survival after first observation. Sixty-one records were of live birds, of which 38 (62.3%) were discovered at sea along the west coast of North America, 18 (29.5%) were encountered inland, and 5 (8.2%) were encountered along the Atlantic coast. Fifteen of the 20 individuals salvaged (19 adults, 1 juvenile) were discovered on lake shores (75.0%) and the other 5 (25.0%) on marine coasts; 85.0% were dead when initially found (15 dead, 2 shot), and 3 (15.0%) were moribund (2 died within one day, 1 later released). Of 10 sexed individuals, 5 were adult males, 4 were adult females, and 1 was a juvenile female. Eight of 10 murrelets observed foraging were diving on lakes, but 2 others surfaced with fish; two species of common freshwater fish were removed from stomachs of 2 birds shot by hunters. Most birds (72.1%, n = 61) disappeared after one observation, which suggests survival and moving on; one bird stayed at the same location for at least 25 days before disappearing. Dead or dying Long-billed Murrelets found on shorelines of fresh water may have been too emaciated to regain lost mass after arrival—they weighed less than those shot, presumably because they were not able to locate prey or too weak to capture it. Survival for weeks or longer on freshwater stopover sites better explains how Long-billed Murrelets move across North America, with some reaching the Atlantic Ocean. Long-surviving vagrants may establish a new breeding population of Long-billed Murrelet on the west coast of North America.

scholarly journals Breeding population of Black Stork, Ciconia nigra, in Italy between 1994 and 2016

2018 ◽  
Vol 88 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Maurizio Fraissinet ◽  
Lucio Bordignon ◽  
Massimo Brunelli ◽  
Matteo Caldarella ◽  
Enzo Cripezzi ◽  
...  
Keyword(s):  
Population Density ◽  
Breeding Population ◽  
Breeding Period ◽  
High Increase ◽  
Nesting Sites ◽  
Central Regions ◽  
Southern Central ◽  
Ciconia Nigra ◽  
Black Stork ◽  
Piedmont Region

The Black Stork Ciconia nigra, following an expansion on European scale, started breeding in Italy in 1994 with one pair in the Piedmont Region and one in the Calabria Region. Since then, the breeding pairs established in Italy have progressively increased up to 18 in 2016, and they are currently in Piedmont, Lazio, Campania, Molise, Apulia, Basilicata and Calabria. However, the number of breeding pairs could be higher than 20, as indicated by records and observations of adults and juveniles, during the breeding period in potentially suitable nesting areas. Despite the low population density in Italy, the trend in the breeding population in Northwest and in Southern Central regions seems to show a slight and high increase respectively. Productivity, breeding success and fledging rate have been considered and analysed. A difference between the two macro areas has been found in the choice of nesting sites, which is on trees for Northwest couples, and cliffs for Southern Central couples. It is necessary to further explore the reason why the small Northwest population does not show any increase and range expansion compared to the Southern Central one.

Causes and consequences of resource heterogeneity in forests: interspecific variation in light transmission by canopy trees

1994 ◽  
Vol 24 (2) ◽  
pp. 337-349 ◽  
Author(s):  
Charles D. Canham ◽  
Adrien C. Finzi ◽  
Stephen W. Pacala ◽  
Diane H. Burbank
Keyword(s):  
New England ◽  
Light Transmission ◽  
Interspecific Variation ◽  
Light Extinction ◽  
Southern New England ◽  
Interspecific Differences ◽  
Tolerant Species ◽  
Shade Tolerant Species ◽  
Successional Species ◽  
Unit Depth

We have analyzed the light transmission characteristics of the nine deciduous and coniferous species that dominate the transition oak–northern hardwood forests of southern New England. Maximum likelihood techniques were used to estimate species-specific light extinction coefficients, using fish-eye photography combined with data on the locations and geometry of trees in the neighborhood around each photo point. Quantum sensors were also used to quantify interspecific variation in the importance of sunflecks and beam enrichment. Variation in light extinction was closely correlated with shade tolerance and successional status of the species. The most shade-tolerant species (Fagusgrandifolia Ehrh. and Tsugacanadensis (L.) Carr.) cast the deepest shade (<2% of full sun), while earlier successional species such as Quercusrubra L. and Fraxinusamericana L. allowed greater light penetration (>5% full sun). These differences were more closely related to differences in crown depth than to differences in light extinction per unit depth of crown. Sunflecks contributed relatively little radiation beneath late successional species (<10% of total understory photosynthetically active radiation), but represented a major fraction (40–50%) of radiation beneath less shade-tolerant species. Using growth and mortality functions for the same species developed in a related study, our results indicate that saplings of all of the species have high survivorship in the shade cast by conspecific adults. However, only the three most shade-tolerant species have low rates of sapling mortality under the low light levels characteristic of stands dominated by late successional species. Our results are consistent with previously reported models, which propose that secondary succession is driven by interspecific differences in resource uptake and tolerance.

scholarly journals Dispersal of the introduced red king crab (Paralithodes camtschaticus) in Norwegian waters: a tag-recapture study

2014 ◽  
Vol 71 (7) ◽  
pp. 1966-1976 ◽  
Author(s):  
Kristin Windsland ◽  
Carsten Hvingel ◽  
Einar M. Nilssen ◽  
Jan H. Sundet
Keyword(s):  
Logistic Regression ◽  
Population Density ◽  
Fishing Effort ◽  
Dispersal Ability ◽  
Large Individual ◽  
Red King Crab ◽  
Paralithodes Camtschaticus ◽  
Dispersal Rate ◽  
Long Distance ◽  
King Crab

Abstract The aim of this study was to explore the effect of sex, size, region, and density on dispersal rate of the introduced red king crab (Paralithodes camtschaticus) in Norwegian waters. We examined the effect of these factors using logistic regression analysis. Tag-recapture data corrected for fishing effort enabled us to estimate dispersal rates from four main regions along the Norwegian coast: Varangerfjorden, Tanafjorden, Laksefjorden, and Porsangerfjorden. The probability of dispersal was independent of sex and size, but both the logistic regression and the evaluation of corrected tag-recapture data revealed differences in dispersal between region and with increasing duration. The recapture data indicated a relationship between population density and dispersal within research regions but not between population density and dispersal between research regions. Our main conclusion is that there are large individual differences in dispersal ability and the range expansion of red king crab is a result of (i) the presence of long-distance dispersers and (ii) time-dependent slow migration by short distance dispersers. We also conclude that there appears less dispersal in Norwegian waters than in native waters, which might be caused by differences in geographical complexity.

Can long-distance migratory birds adjust to the advancement of spring by shortening migration distance? The response of the pied flycatcher to latitudinal photoperiodic variation

2008 ◽  
Vol 14 (11) ◽  
pp. 2516-2522 ◽  
Author(s):  
TIMOTHY COPPACK ◽  
ILSE TINDEMANS ◽  
MICHAEL CZISCH ◽  
ANNEMIE VAN der LINDEN ◽  
PETER BERTHOLD ◽  
...  
Keyword(s):  
Migratory Birds ◽  
Pied Flycatcher ◽  
Long Distance ◽  
Migration Distance

Patterns and correlates of interspecific variation in foliar insect herbivory and pathogen attack in Brazilian cerrado

2001 ◽  
Vol 17 (1) ◽  
pp. 127-148 ◽  
Author(s):  
ROBERT J. MARQUIS ◽  
IVONE R. DINIZ ◽  
HELENA C. MORAIS
Keyword(s):  
Plant Species ◽  
Interspecific Variation ◽  
Dry Season ◽  
Mature Leaf ◽  
Insect Damage ◽  
Wet Season ◽  
Leaf Production ◽  
Leaf Toughness ◽  
Interspecific Differences ◽  
Pathogen Attack

Patterns of insect herbivore and leaf pathogen attack are described for 25 plant species (10 trees, 10 shrubs and five herbs) at a Brazilian savanna (cerrado) site. Plant and leaf traits were correlated with interspecific variation in attack by herbivores and pathogens in order to account for differences among plant species. Across all species, pathogen damage was 1.5 times higher than insect damage (17.3% vs. 6.8%, respectively). Most insect damage occurred to young leaves while they were expanding (end of the dry season). In contrast, pathogen attack was low on young expanding leaves at the end of the dry season, increased as those leaves matured in the wet season, but continued to increase through the next dry season. Protein-binding capacity was negatively associated with interspecific differences in insect damage to mature leaves. Protein availability and plant height were positive predictors of pathogen attack among plant species, while leaf expansion rate was a significant negative predictor. Interspecific differences in leaf phenology had little effect on the amount of damage caused by either insects or pathogens. However, new leaves produced during the wet season suffered less insect damage than leaves produced during the dry season, the time of greatest leaf production. Timing of young leaf production affected pathogen attack but the season of escape depended on plant species. In contrast, there was no evidence for escape in space as common species were less likely to suffer high pathogen attack than rare species. New and mature leaf toughness, and time for a leaf to reach full expansion all increased from herbs to shrub to trees, while mature leaf nitrogen decreased in that order.

scholarly journals Plant neighborhood shapes diversity and reduces interspecific variation of the phyllosphere microbiome

2021 ◽  
Author(s):  
Kyle Matthew Meyer ◽  
Robert Porch ◽  
Isabella E Muscettola ◽  
Ana Luisa S Vasconcelos ◽  
Julia K Sherman ◽  
...  
Keyword(s):  
Neighborhood Effects ◽  
Plant Biomass ◽  
Interspecific Variation ◽  
Interspecific Differences ◽  
Community Profiling ◽  
Bean Plants ◽  
Key Factor ◽  
Local Plant ◽  
Inoculation Study ◽  
Over Time

Microbial communities associated with plant leaf surfaces (i.e. the phyllosphere) are increasingly recognized for their role in plant health. While accumulating evidence suggests a role for host filtering of its microbiota, far less is known about how community composition is shaped by dispersal, including from neighboring plants. We experimentally manipulated the local plant neighborhood within which tomato, pepper, or bean plants were grown in a three-month field trial. Focal plants were grown in the presence of con- or hetero-specific neighbors (or no neighbors) in a fully factorial combination. At 30-day intervals, focal plants were harvested and replaced with a new age- and species-matched cohort while allowing neighborhood plants to continue growing. 16S community profiling revealed that the strength of host filtering effects (i.e. interspecific differences in composition) decreased over time. In contrast, the strength of neighborhood effects increased over time, suggesting dispersal from neighboring plants becomes more important as neighboring plant biomass increases. We next implemented a cross-inoculation study in the greenhouse using inoculum generated from the field plants to directly test host filtering of microbiomes while controlling for directionality and source of dispersal. This experiment further demonstrated that focal host species, the host from which the microbiome came, and in one case the donor hosts' neighbors, contribute to variation in phyllosphere bacterial composition. Overall, our results suggest that local dispersal is a key factor in phyllosphere assembly, and that demographic factors such as nearby neighbor identity and biomass or age are important determinants of phyllosphere microbiome diversity.

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