The effects of agricultural intensification on Skylarks(Alauda arvensis): Evidence from monitoring studies in Great Britain

2000 ◽  
Vol 8 (2) ◽  
pp. 95-113 ◽  
Author(s):  
D E Chamberlain ◽  
G M Siriwardena

Declines in a number of farmland bird species in northern Europe have been linked to agricultural intensification. In this paper, we review the evidence for the effects of agricultural intensification on farmland bird populations using monitoring studies on a single well-studied species, the Eurasian Skylark (Alauda arvensis). Between 1970 and 1998, the Skylark population declined by 44% and this decline was greatest on farmland compared to upland or coastal habitats, yet during that time, reproductive performance per individual nesting attempt improved significantly. Skylarks consistently prefer relatively sparse (spring cereals) or structurally complex (fallow "set-aside"') crops, particularly late in the breeding season when crops that are too tall or dense are abandoned. Outside the breeding season, cereal stubble is the most preferred foraging habitat. Intensification has been characterized by decreases in preferred crops (spring cereals and cereal stubble) and an increase in unfavourable habitats (winter cereals, oilseed rape, and intensively managed or grazed grass). Reduction in the number of breeding attempts due to rapid sward development of winter cereals and the lack of suitable alternative habitats is likely to have been an important factor in the Skylark decline. The decline may also have been driven by decreases in survival outside the breeding season. Management regimes that include spring cereals, cereal stubble, and low-intensity grazing are likely to increase Skylark abundance and will benefit a number of other farmland birds. This review highlights the great value of large-scale monitoring schemes in understanding population declines. However, the factors affecting the post-fledging survival of Skylarks and the effects of crop diversity on Skylark abundance remain to be resolved. Key words: agricultural management, cereals, habitat diversity, intensification, population trend, reproductive performance.

Land ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 306
Author(s):  
Nándor Csikós ◽  
Péter Szilassi

The dramatic decline of the abundance of farmland bird species can be related to the level of land-use intensity or the land-cover heterogeneity of rural landscapes. Our study area in central Europe (Hungary) included 3049 skylark observation points and their 600 m buffer zones. We used a very detailed map (20 × 20 m minimum mapping unit), the Hungarian Ecosystem Basemap, as a land-cover dataset for the calculation of three landscape indices: mean patch size (MPS), mean fractal dimension (MFRACT), and Shannon diversity index (SDI) to describe the landscape structure of the study areas. Generalized linear models were used to analyze the effect of land-cover types and landscape patterns on the abundance of the Eurasian skylark (Alauda arvensis). According to our findings, the proportions of arable land, open sand steppes, closed grassland patches, and shape complexity and size characteristics of these land cover patches have a positive effect on skylark abundance, while the SDI was negatively associated with the skylark population. On the basis of the used statistical model, the abundance density (individuals/km*) of skylarks could be estimated with 37.77% absolute percentage error and 2.12 mean absolute error. We predicted the skylark population density inside the Natura 2000 Special Protected Area of Hungary which is 0–6 individuals/km* and 23746 ± 8968 skylarks. The results can be implemented for the landscape management of rural landscapes, and the method used are adaptable for the density estimation of other farmland bird species in rural landscapes. According to our findings, inside the protected areas should increase the proportion, the average size and shape complexity of arable land, salt steppes and meadows, and closed grassland land cover patches.


2020 ◽  
Vol 723 ◽  
pp. 138056 ◽  
Author(s):  
Rosie J. Lennon ◽  
Will J. Peach ◽  
Jenny C. Dunn ◽  
Richard F. Shore ◽  
M. Glória Pereira ◽  
...  

2020 ◽  
Vol 30 (3) ◽  
pp. 335-354 ◽  
Author(s):  
MALTE BUSCH ◽  
JAKOB KATZENBERGER ◽  
SVEN TRAUTMANN ◽  
BETTINA GERLACH ◽  
RAINER DRÖSCHMEISTER ◽  
...  

SummaryFarmland bird populations in Germany are declining at a higher speed than species inhabiting other habitats. We studied potential causes for bird population changes based on data from standardised German breeding bird monitoring schemes. We related population trends to covariates describing the changes in the agricultural landscape in Germany, weather conditions during the breeding season and for some migratory species, conditions at stopover and wintering sites. Linear mixed effect models were used to analyse effect strength at species level and conclusions are drawn for the overall group of farmland bird species. The area of grassland and fallow land was shown to have the strongest positive effects and the area of maize and rapeseed the strongest negative effects on farmland bird population trends. The results obtained also indicate that despite the consistent influence of weather conditions during the breeding season, land-use changes had a stronger impact on bird populations than weather. Conditions at Sahel wintering sites did not show a consistent effect on population trends. Based on these findings the study quantitatively underpins and ranks key factors shaping farmland bird populations in Germany.


Author(s):  
Yvonne R. Schumm ◽  
Dimitris Bakaloudis ◽  
Christos Barboutis ◽  
Jacopo G. Cecere ◽  
Cyril Eraud ◽  
...  

AbstractDiseases can play a role in species decline. Among them, haemosporidian parasites, vector-transmitted protozoan parasites, are known to constitute a risk for different avian species. However, the magnitude of haemosporidian infection in wild columbiform birds, including strongly decreasing European turtle doves, is largely unknown. We examined the prevalence and diversity of haemosporidian parasites Plasmodium, Leucocytozoon and subgenera Haemoproteus and Parahaemoproteus in six species of the order Columbiformes during breeding season and migration by applying nested PCR, one-step multiplex PCR assay and microscopy. We detected infections in 109 of the 259 screened individuals (42%), including 15 distinct haemosporidian mitochondrial cytochrome b lineages, representing five H. (Haemoproteus), two H. (Parahaemoproteus), five Leucocytozoon and three Plasmodium lineages. Five of these lineages have never been described before. We discriminated between single and mixed infections and determined host species-specific prevalence for each parasite genus. Observed differences among sampled host species are discussed with reference to behavioural characteristics, including nesting and migration strategy. Our results support previous suggestions that migratory birds have a higher prevalence and diversity of blood parasites than resident or short-distance migratory species. A phylogenetic reconstruction provided evidence for H. (Haemoproteus) as well as H. (Parahaemoproteus) infections in columbiform birds. Based on microscopic examination, we quantified parasitemia, indicating the probability of negative effects on the host. This study provides a large-scale baseline description of haemosporidian infections of wild birds belonging to the order Columbiformes sampled in the northern hemisphere. The results enable the monitoring of future changes in parasite transmission areas, distribution and diversity associated with global change, posing a potential risk for declining avian species as the European turtle dove.


Author(s):  
Parker A Henley ◽  
Frank A Ireland ◽  
Igor F Canisso ◽  
J Lannett Edwards ◽  
Daniel W Shike

Abstract This study evaluated the effect of heifer development system on body weight (BW), body condition score (BCS), fescue toxicosis symptoms, reproductive performance, and subsequent calf growth of fall-calving beef heifers. Angus × Simmental heifers [n = 399; 240 ± 20.0 kg initial BW; age = 252 ± 20 d] were stratified by BW and BCS and assigned to 1 of 12 groups in each of the 2 production years. The study utilized a stratified randomized design. Pens were randomly assigned to 4 treatments: drylot (DL) development (fed ad-libitum diet consisting of 90% hay and 10% DDGS on a dry matter basis), grazing endophyte-infected fescue supplemented daily (2.3 kg as-fed/heifer/d; 50:50 mix of soybean hulls and DDGS; E+/S), grazing endophyte-infected fescue and supplemented from the midpoint of treatment period until breeding (4.5 kg as-fed/heifer/d; 50:50 mix of soybean hulls and DDGS; E+/LS), and grazing novel endophyte-infected fescue with no supplement (NE+/NS). Treatments ceased on d 168 [time of artificial insemination (AI)] and heifers were commingled and managed as a group through second breeding season. Heifers in DL had greatest (P ≤ 0.05) BW and BCS from d 28 until d 254. Furthermore, E+/S heifers had greater (P ≤ 0.05) BW and BCS than both E+/LS and NE+/NS from d 28 until d 168. On d 56 and 84, E+/LS heifers had lower (P ≤ 0.05) BW and BCS compared to NE+/NS, but on d 148 treatments reranked and E+/LS remained at a greater (P ≤ 0.05) BW and BCS compared to NE+/NS through the first breeding season. Drylot heifers had greatest (P ≤ 0.05) percentage cycling and percentage of mature BW at AI (66.6%) and had greater (P ≤ 0.05) AI and overall pregnancy rates compared to E+/LS and NE+/NS. The E+/S (55%) and E+/LS (53.7%) heifers were developed to a greater (P < 0.01) percentage of mature BW than NE+/NS (49.3%). A greater (P ≤ 0.02) percentage of DL and E+/S heifers were pregnant at the end of the first breeding season (89.3 and 85.1%; respectively) compared to NE+/NS (61.5%). In summary, DL heifers had the greatest BW and BCS at AI, percentage cycling, and AI pregnancy rate. However, this strategy did not result in differing overall pregnancy rates between DL, E+/S, and E+/LS and there were no differences in milk production, rebreeding reproductive performance, and calf performance between all treatments. Finally, the poorest AI and overall pregnancy rates of the NE+/NS heifers suggests this is not a viable development strategy for fall-born heifers.


Author(s):  
Robert Patchett ◽  
Alexander N. G. Kirschel ◽  
Joanna Robins King ◽  
Patrick Styles ◽  
Will Cresswell

AbstractFemale song is widespread across bird species yet rarely reported. Here, we report the first observations and description of female song in the Cyprus Wheatear Oenanthe cypriaca and compare it to male song through the breeding season. Twenty-five percent of colour-ringed females were observed singing at least once, predominantly in April, compared to 71% of males that continued singing through the breeding period. We suggest that female song may have multiple functions in this species, but it may be especially important in territorial defence and mate acquisition.


Diversity ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 109 ◽  
Author(s):  
Rebecca T. Kimball ◽  
Carl H. Oliveros ◽  
Ning Wang ◽  
Noor D. White ◽  
F. Keith Barker ◽  
...  

It has long been appreciated that analyses of genomic data (e.g., whole genome sequencing or sequence capture) have the potential to reveal the tree of life, but it remains challenging to move from sequence data to a clear understanding of evolutionary history, in part due to the computational challenges of phylogenetic estimation using genome-scale data. Supertree methods solve that challenge because they facilitate a divide-and-conquer approach for large-scale phylogeny inference by integrating smaller subtrees in a computationally efficient manner. Here, we combined information from sequence capture and whole-genome phylogenies using supertree methods. However, the available phylogenomic trees had limited overlap so we used taxon-rich (but not phylogenomic) megaphylogenies to weave them together. This allowed us to construct a phylogenomic supertree, with support values, that included 707 bird species (~7% of avian species diversity). We estimated branch lengths using mitochondrial sequence data and we used these branch lengths to estimate divergence times. Our time-calibrated supertree supports radiation of all three major avian clades (Palaeognathae, Galloanseres, and Neoaves) near the Cretaceous-Paleogene (K-Pg) boundary. The approach we used will permit the continued addition of taxa to this supertree as new phylogenomic data are published, and it could be applied to other taxa as well.


2005 ◽  
Vol 360 (1454) ◽  
pp. 269-288 ◽  
Author(s):  
Richard D Gregory ◽  
Arco van Strien ◽  
Petr Vorisek ◽  
Adriaan W Gmelig Meyling ◽  
David G Noble ◽  
...  

The global pledge to deliver ‘a significant reduction in the current rate of biodiversity loss by 2010’ is echoed in a number of regional and national level targets. There is broad consensus, however, that in the absence of conservation action, biodiversity will continue to be lost at a rate unprecedented in the recent era. Remarkably, we lack a basic system to measure progress towards these targets and, in particular, we lack standard measures of biodiversity and procedures to construct and assess summary statistics. Here, we develop a simple classification of biodiversity indicators to assist their development and clarify purpose. We use European birds, as example taxa, to show how robust indicators can be constructed and how they can be interpreted. We have developed statistical methods to calculate supranational, multi-species indices using population data from national annual breeding bird surveys in Europe. Skilled volunteers using standardized field methods undertake data collection where methods and survey designs differ slightly across countries. Survey plots tend to be widely distributed at a national level, covering many bird species and habitats with reasonable representation. National species' indices are calculated using log-linear regression, which allows for plot turnover. Supranational species' indices are constructed by combining the national species' indices weighted by national population sizes of each species. Supranational, multi-species indicators are calculated by averaging the resulting indices. We show that common farmland birds in Europe have declined steeply over the last two decades, whereas woodland birds have not. Evidence elsewhere shows that the main driver of farmland bird declines is increased agricultural intensification. We argue that the farmland bird indicator is a useful surrogate for trends in other elements of biodiversity in this habitat.


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