scholarly journals The Occurence of Ecological Traps in Bird Populations: Is our Knowledge Sufficient? A Review

2012 ◽  
Vol 5 (3) ◽  
pp. 36-56 ◽  
Author(s):  
Petr Suvorov ◽  
Jana Svobodová

ABSTRACT Anthropogenic changes in a landscape create new cues for birds, which must permanently adapt to these. If landscape changes occur too quickly, individuals have insufficient time to develop adequate reactions. They may, therefore, preferentially nest in low-quality habitats, which can lead to diminished nesting success and to reduction of their population size. This is usually termed the ecological trap hypothesis. We reviewed 38 studies investigating this phenomenon and analysed whether relationships exist between ecological trap occurrence and geographical region, habitat type, and/or life strategies of bird species. Ecological traps were most often associated with the presence of exotic species. Exotic species can modify environmental conditions in ways to which native communities are not adapted. They have been mainly detected in open habitats. Such open habitats as arable fields and meadows are under greater human pressure, and rapid changes probably occur there more frequently. Although more studies from North America were investigated, the hypothesis was supported more frequently in European studies. This is possibly due to higher human population density and, hence, more frequent habitat changes. Our results show that an ecological trap is not likely associated with migration. Ground nests suffered fewer consequences of such traps than did other nest types. Although the implications of the ecological trap hypothesis in species conservation are undisputable, a more detailed approach is still needed. For instance, some habitat types, such as suburban areas, have been neglected in the context of ecological traps, as has been the phenomenon’s appearance in pristine habitats.

2007 ◽  
Vol 34 (1) ◽  
pp. 1-11 ◽  
Author(s):  
GAVIN B. STEWART ◽  
ANDREW S. PULLIN ◽  
CHRISTOPHER F. COLES

Concerns about anthropogenic climate change have resulted in promotion of renewable energy sources, especially wind energy. A concern raised against widespread windfarm development is that it may negatively impact bird populations as a result of bird collision with turbines, habitat loss and disturbance. Using systematic review methodology bird abundance data were synthesized from 19 globally-distributed windfarms using meta-analysis. The effects of bird taxon, turbine number, power, location, latitude, habitat type, size of area, time since operation, migratory status of the species and quality of evidence were analysed using meta-regression. Although the synthesized data suggest a significant negative impact of windfarms on bird abundance, there is considerable variation in the impact of individual windfarm sites on individual bird species, and it is unclear if the negative impact is a decline in population abundance or a decline in use owing to avoidance. Anseriformes experienced greater declines in abundance than other taxa, followed by Charadriiformes, Falconiformes and Accipitriformes, and Passeriformes. Time since windfarms commenced operation also had a significant impact on bird abundance, with longer operating times resulting in greater declines in abundance than short operating times. Other variables, including turbine number and turbine power either had very weak but statistically significant effects or did not have a significant effect on bird abundance. Windfarms may have significant biological impacts, especially over longer time scales, but the evidence-base is poor, with many studies being methodologically weak, and more long-term impact assessments are required. There is clear evidence that Anseriformes (wildfowl) and Charadriiformes (waders) experience declines in abundance, suggesting that a precautionary approach should be adopted to windfarm development near aggregations of these taxa in offshore and coastal locations. The impact of windfarm developments on bird populations must also be viewed in the context of the possible impact of climate change in the absence of windfarms.


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Justin H White ◽  
Jessi L Brown ◽  
Zachary E Ormsby

Abstract Despite the unique threats to wildlife in urban areas, many raptors have established successfully reproducing urban populations. To identify variations in raptor breeding ecology within an urban area, we compared metrics of Red-tailed Hawk reproductive attempts to landscape characteristics in Reno and Sparks, NV, USA during the 2015 and 2016 breeding seasons. We used the Apparent Nesting Success and logistic exposure methods to measure nesting success of the Red-tailed Hawks. We used generalized linear models to relate nesting success and fledge rate to habitat type, productivity to hatch date (Julian day) and hatch date to urban density. Nesting success was 86% and 83% for the respective years. Nesting success increased in grassland-agricultural and shrub habitats and decreased in riparian habitat within the urban landscape. Productivity was 2.23 and 2.03 per nest for the breeding seasons. Fledge rates were 72% and 77%, respectively, and decreased in riparian areas. Nestlings hatched earlier with increased urban density and earliest in suburban areas, following a negative quadratic curve. Nesting success and productivity for this population were high relative to others in North America. Productivity increased in habitats where ground prey was more accessible. We suggest that suburban areas, if not frequently disturbed, provide sufficient resources to sustain Red-tailed Hawks over extended periods. As urban expansion continues in arid environments globally, we stress that researchers monitor reproductive output across the urban predator guild to elucidate patterns in population dynamics and adaptation.


Ecosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Geoffrey A. Fricker ◽  
Lisa H. Crampton ◽  
Erica M. Gallerani ◽  
Justin M. Hite ◽  
Richard Inman ◽  
...  

Land ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 487
Author(s):  
Lillian Collins ◽  
Grant D. Paton ◽  
Sara A. Gagné

The urbanization of landscapes filters bird communities to favor particular species traits, driven in part by the changes that homeowners make to the amount and quality of habitat in yards. We suggest that an ultimate driver of these proximate mechanisms underlying bird community change with respect to urbanization is the likeability of species traits by urban residents. We hypothesize that bird species likeability, modulated by species traits, influences the degree to which homeowners alter the availability and quality of habitat on their properties and thereby affects species population sizes in urbanized landscapes. We refer to this new hypothesis as the Likeable, therefore Abundant Hypothesis. The Likeable, therefore Abundant Hypothesis predicts that (1) bird species likeability varies with species morphological and behavioral traits, (2) homeowners use trait-based likeability as a motivator to modify habitat availability and quality on their properties, and (3) residential habitat availability and quality influences species populations at landscape scales. We tested the first prediction of the Likeable, therefore Abundant Hypothesis using a survey of 298 undergraduate students at the University of North Carolina at Charlotte who were asked to rank their preferences for 85 forest generalist and edge/open country songbird species grouped according to 10 morphological and behavioral traits. Survey respondents preferred very small, primarily blue or black species that are insectivorous, aerial or bark foragers, residents, and culturally unimportant. On the other hand, respondents disliked large or very large, primarily yellow or orange species that forage on the ground and/or forage by flycatching, are migratory, and are culturally important. If the Likeable, therefore Abundant Hypothesis is true, natural resource managers and planners could capitalize on the high likeability of species that are nevertheless negatively affected by urbanization to convince homeowners and residents to actively manage their properties for species conservation.


Author(s):  
Andersonn Silveira Prestes

The establishment and spread of exotic species is a contemporary major concern. Alien species may become invasive in their new habitat, leading to both/either environmental and/or economic impacts. I briefly reviewed the literature in the last decade about the relationship of exotic species and native communities. I identified that professionals usually approach the subject in two main points of view: (1) researchers tend to point out the impacts of alien species on entire communities, evaluating if the relationship is positive, negative or neutral; (2) they focus on the eco-evolutionary processes involved in the introductions, the dynamics of invasion, and individual study cases. When evaluating the response of introductions to entire communities, evidence seems to be ambiguous and may support positive, negative or neutral relationship, especially depending on the scale approached. The unique eco-evolutionary pathways of each introduction may be a great shortcoming in the searching for generalities. On the other hand, advances have been made in understanding the dynamics of invasion on different lineages through a more selective/individualized approach. I suggest that the dynamics of invasion might be studied through a perspective in which different eco-evolutionary processes, levels of organization (from gene to entire communities), the history of the organism(s) and time are taken into account. Individual cases might be compared in attempt to understand how the relationship exotic and native works and in the search for generalities.


2018 ◽  
Vol 29 (03) ◽  
pp. 339-360 ◽  
Author(s):  
MARIANA BULGARELLA ◽  
MARTÍN A. QUIROGA ◽  
GEORGE E. HEIMPEL

SummaryThe declining-population paradigm holds that small populations are particularly vulnerable to anthropogenic influences such as habitat destruction, pollution and species introductions. While the effects of particular stressors, such as parasitism, may be unimportant in a large, healthy population, they can be serious and even devastating in situations characterised by a restricted geographic range, or by fragmented or reduced population sizes. We apply this idea to nest parasitism of threatened Neotropical bird species that exist in small populations, focusing on dipteran nest parasites in the genusPhilornis. We review the literature onPhilornisparasitism exerting negative pressure on bird populations that have become small and isolated due to human actions and present a new case ofPhilornisparasitism of a threatened hummingbird species. Our aim is to raise awareness about the exacerbating effect that nest parasites can have on small and declining bird populations; especially when biological information is scarce. The five reviewed cases involve two species of Darwin’s Finches in the Galápagos Islands attacked by the invasiveP. downsi, two species of hawks on islands in the Caribbean attacked by the nativeP. piciandP. obscura, and the Yellow CardinalGubernatrix cristatain southern South America attacked by an unknownPhilornisspecies. We also present new documentation of parasitism of a threatened hummingbird species in mainland Ecuador by an unidentifiedPhilornisspecies. We recommend more field studies to determine the presence of nest parasites in bird populations worldwide to improve understanding how nest parasites affect bird fitness and population viability and to allow time to act in advance if needed. Parasitism byPhilornismay represent a severe mortality factor in most already threatened bird species, putting them at greater risk of extinction. Therefore, parasitism management should be included in all threatened species recovery plans.


2020 ◽  
Vol 16 (1) ◽  
pp. 20190763 ◽  
Author(s):  
Nicola Hemmings ◽  
Simon Evans

Prenatal mortality is typically overlooked in population studies, which biases evolutionary inference by confounding selection and inheritance. Birds represent an opportunity to include this ‘invisible fraction’ if each egg contains a zygote, but whether hatching failure is caused by fertilization failure versus prenatal mortality is largely unknown. We quantified fertilization failure rates in two bird species that are popular systems for studying evolutionary dynamics and found that overwhelming majorities (99.9%) of laid eggs were fertilized. These systems thus present opportunities to eliminate the invisible fraction from life-history data.


1987 ◽  
Vol 14 (3) ◽  
pp. 331 ◽  
Author(s):  
GW Arnold ◽  
RA Maller ◽  
R Litchfield

Data were obtained during 2 yr at Baker's Hill, Western Australia, in farmland with no trees, scattered trees or clumps of trees and 3 types of open woodland. There were differences in the number of bird species found in each habitat, ranging from 25 in woodland habitats to 11 in open farmland. In autumn, there were more aerial feeders in open farmland and farmland with few trees than in farmland with many trees and woodland, but fewer in spring. There were more ground-feeding seed-eaters in farmland with trees than elsewhere, except in autumn. There were large seasonal reciprocal changes in the numbers of thornbills in farmland with many trees and woodland, indicating movement between habitats. Within the woodland habitats there were only small seasonal changes, but there were large differences in numbers of some groups between the 3 habitats.


Pathogens ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 304 ◽  
Author(s):  
Francesca Marotta ◽  
Anna Janowicz ◽  
Lisa Di Marcantonio ◽  
Claudia Ercole ◽  
Guido Di Donato ◽  
...  

Poultry is considered a major reservoir of human campylobacteriosis. It also been reported that not only poultry, but also wild birds, are capable of carrying C. jejuni, thus demonstrating to be a risk of spreading the bacteria in the environment. To gain insight into the population structure and investigate the antimicrobial resistance genotypes and phenotypes, we analyzed a collection of 135 C. jejuni from 15 species of wild birds in Italy. MLST revealed the presence of 41 sequence types (STs) and 13 clonal complexes (CCs). ST-179 complex and the generalist ST-45 complex were the most prevalent. Core genome MLST revealed that C. jejuni from ST-45 complex clustered according to the bird species, unlike the ST-179 complex which featured 3 different species in the same cluster. Overall we found a moderate prevalence of resistance to tetracycline (12.5%), ciprofloxacin and nalidixic acid (10%). The novel ST isolated from one pigeon showed resistance to all the antibiotics tested. The ST-179 complex (33.3%) was identified with significantly higher nalidixic acid resistance relative to other tested STs. Nine AMR genes (tet(O), cmeA, cmeB, cmeC, cmeR, aad, blaOXA-61, blaOXA-184 and erm(B)) and 23S rRNA and gyrA-associated point mutations were also described, indicating a concordance level between genotypic and phenotypic resistance of 23.3%, 23.4% and of 37.5% for streptomycin, tetracycline and quinolones/fluoroquinolones, respectively. We recommend that particular attention should be given to wild birds as key sentinel animals for the ecosystem contamination surveillance.


2017 ◽  
Vol 3 (2) ◽  
pp. 1-18 ◽  
Author(s):  
Lucas M. Leveau ◽  
Jukka Jokimäki ◽  
Marja-Liisa Kaisanlahti-Jokimäki

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.


Sign in / Sign up

Export Citation Format

Share Document