Changes in the structure of bird communities over 10 years in the Ecological Corridor of Paraguay River, Pantanal wetland

Studies with bird communities related to the hydrogeomorphological characteristics of climatic rivers associated with flood areas are important to identify short and long term temporal space changes. In this perspective, this research aims to evaluate the structure of the bird community of the Paraguay River, through the richness of descriptors, the quantity and the diversity and equability index over an interval of 10 years, 2008 / 9-2018 / 19 , considering the economies of the hydrological cycle, floods, floods, emptiness and drought and sampled macrohabitats. The study was developed addressing a connected hydrology of the Paraguay River, in the longitudinal and lateral dimensions. A study area comprised of three functional sectors of the Paraguay River, meandering, rectilinear and transitional, beginning in the urban period of the municipality of Cáceres-MT, up to a Descalvada Farm, with a 134 km course of the river, with 13 points in total. Each functional sector of the river, had a sampling point and 10 parental bays, with different degrees of lateral connectivity, were sampled. A survey analyzed and compared two hydrological sampling cycles, the first between June 2008 and March 2009, and the second between August 2018 and April 2019. The protocol for the sampling consisted of four campaigns corresponding to the hydrological drought studies, flood, full and ebb. The results pointed to a distinction in the community structure between the two cycles 2008/2009 - 2018/2019 show a difference in the relative scope and in the composition of the species in the sampled locations. The main change registered between the two cycles (2008/2009 and 2018/2019) was the disappearance of three nests - habitat for feeding and reproduction of colonial birds, identified in the first and without registration in the second cycle. The dominance of Mycteria americana is highlighted, a species sensitive to environmental changes, not observed in the first cycle of studies. The absence of nests in 2018/2019, coupled with the dominance of Pitangus sulphuratus, a generalist species, may indicate anthropic changes that occurred along the Paraguay River in this time interval. It is hoped that the results of this comparison will be able to subsidize or influence the effective decision-making for the conservation of the biodiversity of birds and the Paraguay and Pantanal river itself.

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Current understanding on the Cambrian Explosion: questions and answers

PalZ ◽

10.1007/s12542-021-00568-5 ◽

2021 ◽

Author(s):

Xingliang Zhang ◽

Degan Shu

Keyword(s):

Environmental Changes ◽

Size Variation ◽

Progressive Increase ◽

Cambrian Explosion ◽

Time Interval ◽

Early Cambrian ◽

Ecological Processes ◽

Questions And Answers ◽

Evolutionary Event ◽

History Of

AbstractThe Cambrian Explosion by nature is a three-phased explosion of animal body plans alongside episodic biomineralization, pulsed change of generic diversity, body size variation, and progressive increase of ecosystem complexity. The Cambrian was a time of crown groups nested by numbers of stem groups with a high-rank taxonomy of Linnaean system (classes and above). Some stem groups temporarily succeeded while others were ephemeral and underrepresented by few taxa. The high number of stem groups in the early history of animals is a major reason for morphological gaps across phyla that we see today. Most phylum-level clades achieved their maximal disparity (or morphological breadth) during the time interval close to their first appearance in the fossil record during the early Cambrian, whereas others, principally arthropods and chordates, exhibit a progressive exploration of morphospace in subsequent Phanerozoic. The overall envelope of metazoan morphospace occupation was already broad in the early Cambrian though it did not reach maximal disparity nor has diminished significantly as a consequence of extinction since the Cambrian. Intrinsic and extrinsic causes were extensively discussed but they are merely prerequisites for the Cambrian Explosion. Without the molecular evolution, there could be no Cambrian Explosion. However, the developmental system is alone insufficient to explain Cambrian Explosion. Time-equivalent environmental changes were often considered as extrinsic causes, but the time coincidence is also insufficient to establish causality. Like any other evolutionary event, it is the ecology that make the Cambrian Explosion possible though ecological processes failed to cause a burst of new body plans in the subsequent evolutionary radiations. The Cambrian Explosion is a polythetic event in natural history and manifested in many aspects. No simple, single cause can explain the entire phenomenon.

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The impact of Sosnowsky’s Hogweed on feeding guilds of birds

Journal of Ornithology ◽

10.1007/s10336-021-01898-6 ◽

2021 ◽

Author(s):

Emilia Grzędzicka ◽

Jiří Reif

Keyword(s):

Negative Impact ◽

Bird Community ◽

Plant Invasions ◽

Bird Communities ◽

Feeding Guilds ◽

Guild Structure ◽

Feeding Guild ◽

Potential Impact ◽

Underlying Mechanisms ◽

The Impact

AbstractPlant invasions alter bird community composition worldwide, but the underlying mechanisms still require exploration. The investigation of feeding guild structure of bird communities can be informative in respect to the potential impact of invasion features on the availability of food for birds. For this purpose, we focused on determining the influence of the invasive Sosnowsky’s Hogweed Heracleum sosnowskyi on the abundance of birds from various feeding guilds. In spring and summer 2019, birds were counted three times on 52 pairs of sites (control + Heracleum) in southern Poland, at various stages of Sosnowsky’s Hogweed development (i.e. sprouting, full growth and flowering, all corresponding to respective bird counts). We have shown that the presence of invader negatively affected the abundance of birds from all feeding guilds. However, a closer examination of the invaded sites uncovered that responses of particular guilds differed in respect to development stages expressed by a set of characteristics of the invader. Ground and herb insectivores were more common on plots with a higher number of the invader, while the abundance of bush and tree insectivores was negatively correlated with hogweeds’ height. Granivores were not affected by the invader’s features, while the abundance of omnivores was negatively related to the number of flowering hogweeds. Besides showing the general negative impact of the invader on different feeding guilds, our research has shown that certain aspects of Sosnowsky’s Hogweed invasion may support or depress occurrence of different birds on invaded plots. Knowledge of these aspects may facilitate our capacity for coping with challenges the invasive plants put in front of bird conservationists.

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Hydrological cycle

Brazilian Journal of Biology ◽

10.1590/s1519-69842011000200003 ◽

2011 ◽

Vol 71 (1 suppl 1) ◽

pp. 241-253 ◽

Cited By ~ 39

Author(s):

HC Gonçalves ◽

MA Mercante ◽

ET Santos

Keyword(s):

Water Resources ◽

Hydrological Cycle ◽

Mato Grosso ◽

Climate Conditions ◽

Paraguay River ◽

Rivers And Lakes ◽

Drainage Capacity ◽

The Relationship ◽

Average Annual Precipitation ◽

Very High

The Pantanal hydrological cycle holds an important meaning in the Alto Paraguay Basin, comprising two areas with considerably diverse conditions regarding natural and water resources: the Plateau and the Plains. From the perspective of the ecosystem function, the hydrological flow in the relationship between plateau and plains is important for the creation of reproductive and feeding niches for the regional biodiversity. In general, river declivity in the plateau is 0.6 m/km while declivity on the plains varies from 0.1 to 0.3 m/km. The environment in the plains is characteristically seasonal and is home to an exuberant and abundant diversity of species, including some animals threatened with extinction. When the flat surface meets the plains there is a diminished water flow on the riverbeds and, during the rainy season the rivers overflow their banks, flooding the lowlands. Average annual precipitation in the Basin is 1,396 mm, ranging from 800 mm to 1,600 mm, and the heaviest rainfall occurs in the plateau region. The low drainage capacity of the rivers and lakes that shape the Pantanal, coupled with the climate in the region, produce very high evaporation: approximately 60% of all the waters coming from the plateau are lost through evaporation. The Alto Paraguay Basin, including the Pantanal, while boasting an abundant availability of water resources, also has some spots with water scarcity in some sub-basins, at different times of the year. Climate conditions alone are not enough to explain the differences observed in the Paraguay River regime and some of its tributaries. The complexity of the hydrologic regime of the Paraguay River is due to the low declivity of the lands that comprise the Mato Grosso plains and plateau (50 to 30 cm/km from east to west and 3 to 1.5 cm/km from north to south) as well as the area's dimension, which remains periodically flooded with a large volume of water.

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Status, diversity and trends of the bird communities in Volcanoes National Park and surrounds, Rwanda

Bird Conservation International ◽

10.1017/s0959270919000121 ◽

2019 ◽

Vol 30 (1) ◽

pp. 1-20 ◽

Cited By ~ 1

Author(s):

MIA A. DERHÉ ◽

DEO TUYISINGIZE ◽

WINNIE ECKARDT ◽

FAIDA EMMANUEL ◽

TARA STOINSKI

Keyword(s):

National Parks ◽

National Park ◽

Mixed Forest ◽

Basal Area ◽

Bird Community ◽

Bird Communities ◽

Population Pressure ◽

Bird Diversity ◽

Albertine Rift ◽

1960S And 1970S

SummaryThe Volcanoes National Park (VNP) in Rwanda, part of the Virunga massif in the Albertine Rift region, boasts some of Rwanda’s best remaining natural vegetation and is home to many endangered and endemic species. The park has suffered from high levels of degradation and destruction, reducing in size by 50% during the 1960s and 1970s, and remains under threat from illegal activities, human population pressure and climate change. This study is the first to investigate the status and trends of bird communities in the VNP, using a multi-year dataset. We use a five-year dataset, totalling over 3,200 point-counts, both within and around the VNP, to assess the conservation value of the VNP for birds in comparison with other national parks and non-protected areas. We assess bird communities and population trends within and around the parks and identify important habitat factors for birds within the VNP. We found that the VNP hosts a unique bird community compared to other localities, with several Albertine Rift endemics and threatened species occurring in the VNP. Hagenia/ Hypericum woodland, herbaceous vegetation, brush ridge and mixed forest host the highest levels of bird diversity in the VNP, whilst the park’s waterbodies provide key habitat for the endangered Albertine Rift endemic Grauer’s Swamp-warbler (Bradypterus graueri). Elevation had a negative effect on bird diversity in the VNP, whilst the basal area of dead trees, Hagenia and vines had a positive effect. Both inside and outside the VNP, there was a significant decline in abundance and species richness over the sampling years; however, we advocate for further monitoring to confirm these trends. Based on our findings, we recommend effective, targeted management of key habitats for birds within the park, including those identified in this study, in order to mitigate bird declines and conserve the unique bird communities in the VNP.

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Effects of proximity to urban areas on a riparian bird community in remnant Atlantic Forest in southeastern Brazil

Ambiente e Agua - An Interdisciplinary Journal of Applied Science ◽

10.4136/ambi-agua.2313 ◽

2019 ◽

Vol 14 (7) ◽

pp. 1

Author(s):

Ana Cecília de Paula Lourenço ◽

Maria Cecília Barbosa de Toledo

Keyword(s):

Urban Areas ◽

Riparian Forest ◽

Bird Species ◽

Bird Community ◽

Habitat Characteristics ◽

Southeastern Brazil ◽

Average Height ◽

Trophic Groups ◽

Generalist Species ◽

Canopy Opening

The goal of this study was to evaluate the effect of urban activities on the structure and composition of a bird community in riparian forests in the state of São Paulo, Brazil. The study was carried out in seven areas of remnant riparian forest where fixed points have been established to sample bird species. Richness, diversity, abundance, frequency and trophic groups were used as metrics of the bird community. At each point measurements were taken for: (1) habitat characteristics: average height of trees, number of trees above 2m, number of shrubs <2m and the percentage of canopy opening; (2) neighborhood characteristics: closest distance from open areas, highways, urban areas, river and floodplain to the point of observation. The observations resulted in 88 species of birds belonging to 34 families. The most representative families were Tyrannidae, Thraupidae and Picidae. The most predominant trophic groups were insectivorous (54%), omnivorous (11.5%) and frugivorous (10.3%). The results obtained showed that the number of trees explained the variation in abundance, while the mean height of the trees explained variations in richness and frequency. Overall, the bird community was negatively affected by proximity of urban areas and highways. In conclusion, the community of birds in the riparian forest may be affected by the loss of trees above 2m and by urbanization, leading mainly to the replacement of species belonging to specialist trophic groups by generalist species and those more adjusted to human presence.

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Scale dependence of biotic homogenisation by urbanisation: a comparison of urban bird communities between central Argentina and northern Finland

European Journal of Ecology ◽

10.1515/eje-2017-0011 ◽

2017 ◽

Vol 3 (2) ◽

pp. 1-18 ◽

Cited By ~ 9

Author(s):

Lucas M. Leveau ◽

Jukka Jokimäki ◽

Marja-Liisa Kaisanlahti-Jokimäki

Keyword(s):

Species Turnover ◽

Regional Scale ◽

Bird Species ◽

Bird Community ◽

Bird Communities ◽

Urban Habitats ◽

Suburban Areas ◽

Biotic Homogenisation ◽

Community Dissimilarity ◽

The Town

AbstractRecent studies showed contrasting results about the homogenising force of urbanisation on bird community composition at large and regional scales. We studied whether urbanisation promotes the homogenisation of wintering bird communities and if this varies when comparing towns located within a specific region and towns located in two different biomes of two countries. We used both similarity indices based on the presence/absence data and the abundance data in comparing communities. Processes governing bird community dissimilarity between urbanisation levels were examined with the partitioning of Sörensen index in species turnover and nestedness. We made bird surveys in town centres and suburban habitats of three cities located in the Pampean region of Argentina and in the boreal region of Finland using a single-visit study plot method. Rarefacted species richness did not differ amongst the town centres between the countries, but it was higher in the suburban areas of Argentina than in Finland. At the country-level comparison, we found a higher similarity amongst the town centres than amongst the suburban areas; whereas at the regional comparison, similarity between town centres was comparable to the similarity between suburban areas. The use of an abundance-based index produced a higher similarity between town centre communities of both countries than when using a presence-based index. The dissimilarity between habitats in Argentina was related to nestedness and to species turnover in Finland. Our results indicate that urban-based biotic homogenisation of bird communities is dependent on the scale used, being more evident when comparing cities of different biomes where the same and abundant bird species, such as sparrows and doves, dominate. At the regional scale, quite a high beta-diversity can still be found within urban habitats. Processes of community dissimilarity between urban habitats may differ according to the regional pool of species, being more related to nestedness toward the tropics.

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The impact of African aridity on the isotopic signature of Atlantic deep waters across the Middle Pleistocene Transition

Quaternary Research ◽

10.1016/j.yqres.2011.09.010 ◽

2012 ◽

Vol 77 (1) ◽

pp. 182-191 ◽

Cited By ~ 4

Author(s):

Bruno Malaizé ◽

Elsa Jullien ◽

Amandine Tisserand ◽

Charlotte Skonieczny ◽

E. Francis Grousset ◽

...

Keyword(s):

Deep Water ◽

Benthic Foraminifera ◽

Environmental Changes ◽

Phase Relationship ◽

Isotopic Signature ◽

Middle Pleistocene ◽

Time Interval ◽

Deep Waters ◽

Time Period ◽

The Impact

A high resolution analysis of benthic foraminifera as well as of aeolian terrigenous proxies extracted from a 37 m-long marine core located off the Mauritanian margin spanning the last ~ 1.2 Ma, documents the possible link between major continental environmental changes with a shift in the isotopic signature of deep waters around 1.0–0.9 Ma, within the so-called Mid-Pleistocene Transition (MPT) time period. The increase in the oxygen isotopic composition of deep waters, as seen through the benthic foraminifera δ18O values, is consistent with the growth of larger ice sheets known to have occurred during this transition. Deep-water mass δ13C changes, also estimated from benthic foraminifera, show a strong depletion for the same time interval. This drastic change in δ13C values is concomitant with a worldwide 0.3‰ decrease observed in the major deep oceanic waters for the MPT time period. The phase relationship between aeolian terrigeneous signal increase and this δ13C decrease in our record, as well as in other paleorecords, supports the hypothesis of a global aridification amongst others processes to explain the deep-water masses isotopic signature changes during the MPT. In any case, the isotopic shifts imply major changes in the end-member δ18O and δ13C values of deep waters.

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Changes in hydrological behaviour: case studies of the Unica and Rižana karst springs, Slovenia

10.5194/egusphere-egu2020-12961 ◽

2020 ◽

Author(s):

Natasa Ravbar ◽

Gregor Kovačič ◽

Metka Petrič

Keyword(s):

Land Use ◽

Large Scale ◽

Environmental Changes ◽

Hydrological Cycle ◽

Land Use Changes ◽

Precipitation Amount ◽

Flood Pulse ◽

Karst Springs ◽

The Impact ◽

Gauging Station

<p>Environmental changes, such as alterations in precipitation and evapotranspiration regimes, changes in vegetation type, etc. are triggering direct impact on hydrological cycle through modified amounts and patterns of recharge conditions, as well as occurrence of more frequent and severe hydrometeorological events. Karst aquifers are particularly vulnerable to these effects due to highly dynamic hydrological processes. In this study, we were interested in studying the possibilities to observe changed hydrological behaviour of karst springs on a human timescale. Therefore, we focused on two examples in Slovenia, both regionally important for freshwater supply, agriculture and hydropower. The Unica spring mostly drains areas under moderate continental climate. Its catchment has been repeatedly and severely hit by natural disasters (e.g., ice break, bark beetle attack, windthrow) after 2014 causing large-scale forest disturbances. The catchment of Ri&#382;ana spring, on the other hand, belongs to the moderate Submediterranean climate. There these types of disturbance did not occur in recent years (excluding some wildfires), but the catchment has been liable to substantial land use changes in the past six decades. For assessment of vegetation cover changes and large-scale disturbances in forests, historical digital orthophotos of the Surveying and Mapping Authority of the Republic of Slovenia since 1957 have been compared with the recent land use data provided by Ministry of Agriculture, Economy and Food and forest state database of Slovenian Forest Service. At the same time, hydrological data of the Unica (Hasberg gauging station) in the period 1962-2018 and Ri&#382;ana springs (Kubed gauging station) in the period 1966-2018 and precipitation data from Postojna (period 1962-2018) and Podgrad (period 1966-2018) meteorological stations have been processed. Individual flood pulse events over the 57 years for Unica and 53 years for Ri&#382;ana have been separated. For each flood pulse various information about precipitation amount and intensity, duration of discharge increase, its intensity and amplitude have been specified. We compared these findings with the calculated trends of meteorological and hydrological variables and also changes in land use. The impact of particular environmental change on discharge values of both springs has been evaluated, showing that both, climate and land-use changes, have considerable impact on hydrological regime of studied karst springs. In particular, altered duration of flood pulses increase, their amplitude and intensity have been observed, meaning that the most important issues of water availability that are crucial for water-dependant economic sectors are under threat.</p>

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Changing densities of generalist species underlie apparent homogenization of UK bird communities

Ibis ◽

10.1111/ibi.12370 ◽

2016 ◽

Vol 158 (3) ◽

pp. 645-655 ◽

Cited By ~ 7

Author(s):

Martin J. P. Sullivan ◽

Stuart E. Newson ◽

James W. Pearce-Higgins

Keyword(s):

Bird Communities ◽

Generalist Species

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Changes in the breeding bird communities on mires and in surrounding forests in southeastern Norway during a 40-year period (1976–2015)

Ornis Norvegica ◽

10.15845/on.v39i0.996 ◽

2016 ◽

Vol 39 ◽

pp. 11

Author(s):

Svein Dale ◽

Geir Hardeng

Keyword(s):

Bird Community ◽

Negative Influence ◽

Bird Communities ◽

Sufficient Data ◽

Forest Species ◽

Population Changes ◽

Marginal Populations ◽

Long Distance ◽

Breeding Bird ◽

Number Of Individuals

The breeding bird communities of 18 mires and surrounding forests in southeastern Norway were censused in 1976–77 and in 2015. We found that 53% of the mire species with sufficient data for analyses showed significant changes. Red-throated Diver Gavia stellata, Common Crane Grus grus, Wood Sandpiper Tringa glareola and Tree Pipit Anthus trivialis increased, whereas Northern Lapwing Vanellus vanellus, Black-headed Gull Chroicocephalus ridibundus, Meadow Pipit Anthus pratensis and Yellow Wagtail Motacilla flava decreased. There were also near significant decreases of Eurasian Curlew Numenius arquata and Eurasian Skylark Alauda arvensis. Population changes did not differ between short- and long-distance migrants. Species with marginal populations on mires declined more than mire specialist species, suggesting an indirect negative influence of problems in other habitats. Overall, there was a significant 19% decline in number of mire species, but a non-significant 7% increase in number of individuals. The bird community in the forests surrounding the mires showed significant population changes for 42% of the species with sufficient data for analyses, with increases in many resident forest species, but less so for migrants. Overall, there was a near significant 12% increase in number of forest species, and a significant 28% increase in number of individuals. Mire- and forest-associated species did not differ in population trends. Among short-distance migrants (mire and forest species combined), species wintering in agricultural habitats had more negative population changes than species wintering in other habitats. Thus, the breeding bird community on and around mires in this part of Norway has undergone large changes during the last 40 years. We discuss our results in relation to general trends of bird communities in northern Europe.

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