scholarly journals Electromagnetic Pollution as a Possible Explanation for the Decline of House Sparrows in Interaction with Other Factors

Birds ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 329-337
Author(s):  
Alfonso Balmori

In recent decades, there has been a decline of the House Sparrow (Passer domesticus), mainly in European cities, and several hypotheses have been proposed that attempt to determine the causes of this rapid decline. Previous studies indicated that house sparrows were significantly negatively associated with increasing electromagnetic radiation and sparrows disappeared from areas most polluted. In addition, there are many studies on the impact of radiation on other bird and non-bird species, as well as numerous laboratory studies that demonstrated detrimental effects at electric field strength levels that can be found in cities today. Electromagnetic radiation is the most plausible factor for multiple reasons, including that this is the only one that affects the other hypotheses proposed so far. It is a type of pollution that affects productivity, fertility, decreases insects (chicken feed), causes loss of habitat, decreases immunity and can promote disease. Additionally, the recent sparrow decline matches the deployment of mobile telephony networks. Further, there are known mechanisms of action for non-thermal effects of electromagnetic radiation that may affect sparrows causing their decline. Thus, electromagnetic radiation must be seriously considered as a factor for house sparrows’ decline, probably in synergy with the other factors previously proposed.

Author(s):  
Veera Mahesh ◽  
Suseela Lanka

Background: The House Sparrow (Passer domesticus L.), is a human-commensal bird species, belonging to the order Passeriformes. The rapid changes in our lifestyle resulted in the decrease of this bird population during the past four decades. Among the various causes viz., lack of food resources, pollution pressure, indiscriminate usage of pesticides etc. Habitat loss is found to be one of the main threats for their rapid decline. Installation of artificial nest boxes was found to be the best alternatives for raising the bird population. Methods: Jangareddigudem of West Godavari district, Andhra Pradesh, India, was chosen as the study area. The nest boxes were designed by incorporating certain modifications to the basic model specified by British Trust of Ornithology. Installation of the nest boxes was initiated from an area with moderate food resources, located towards south-west edge of the town and was expanded in to other areas in a latitudinal wise towards north and south directions. Data was collected on a regular basis to study the occupancy of the nest boxes by the house sparrows. Result: The model designed was proved to be protective from predators and also well accepted by the public. Out of 570 nests that were installed in the study area, 550 nests were occupied and being used for breeding, that comes to around 97.6% occupancy indicating the suitability and protectiveness of this model. The sparrow population in the study area has been increased with a count of sparrows from few to 300+ sparrows at each roosting site (two roosting sites) by the end of 2020 by utilizing the nest boxes.


2007 ◽  
Vol 34 (2) ◽  
pp. 307-317 ◽  
Author(s):  
J. SEITZ

Modernization of agriculture, economic development and population increase after the end of the Thirty Years' War caused authorities in many parts of Germany to decree the eradication of so-called pest animals, including the House Sparrow. Farmers were given targets, and had to deliver the heads of sparrows in proportion to the size of their farms or pay fines. At the end of the eighteenth century German ornithologists argued against the eradication of the sparrows. During the mid-nineteenth century, C. L. Gloger, the pioneer of bird protection in Germany, emphasized the value of the House Sparrow in controlling insect plagues. Many decrees were abolished because either they had not been obeyed, or had resulted in people protecting sparrows so that they always had enough for their “deliveries”. Surprisingly, various ornithologists, including Ernst Hartert and the most famous German bird conservationist Freiherr Berlepsch, joined in the war against sparrows at the beginning of the twentieth century, because sparrows were regarded as competitors of more useful bird species. After the Second World War, sparrows were poisoned in large numbers. Persecution of sparrows ended in Germany in the 1970s. The long period of persecution had a significant but not long-lasting impact on House Sparrow populations, and therefore cannot be regarded as a factor in the recent decline of this species in urban and rural areas of western and central Europe.


1996 ◽  
Vol 271 (3) ◽  
pp. R561-R568 ◽  
Author(s):  
E. Caviedes-Vidal ◽  
W. H. Karasov

We acclimated house sparrows (Passer domesticus; 26 g) to high-starch (HS), high-protein (HP), and high-lipid (HL) diets and tested the predictions that uptake of D-glucose and amino acids will be increased with increased levels of dietary carbohydrate and protein, respectively. HS birds had lower mediated D-glucose uptake rate than HP birds. Total uptake of L-leucine at low concentration (0.01 mM), but not of L-proline at 50mM, was increased by dietary protein. Measures of D-glucose maximal mediated uptake (1.2 +/- 0.2 nmol.min-1.mg-1) and intestinal mass (1 g) indicated that the intestine's mediated uptake capacity was only approximately 10% of the D-glucose absorbed at the whole animal level. This implied that nonmediated glucose absorption predominated. We applied a pharmacokinetic technique to measure in vivo absorption of L-glucose, the stereoisomer that does not interact with the Na(+)-glucose cotransporter. At least 75% of L-glucose that was ingested was apparently absorbed. This adds to the increasing evidence that substantial passive glucose absorption occurs in birds and may explain why mediated D-glucose uptake does not increase on high-carbohydrate diets.


The Condor ◽  
2000 ◽  
Vol 102 (2) ◽  
pp. 342-348 ◽  
Author(s):  
R. R. Whitekiller ◽  
David F. Westneat ◽  
P. L. Schwagmeyer ◽  
Douglas W. Mock

Abstract For House Sparrows, Passer domesticus, it has been proposed that the size of a male's throat badge correlates with his success in avoiding cuckoldry as well as obtaining extra-pair copulations (EPCs), and that females gain indirect (genetic) benefits from EPCs with large-badged males. Alternatively, female House Sparrows may engage in EPCs as a guard against their social mate's infertility. We used multi-locus DNA fingerprinting to examine paternity and found that among 41 broods and 136 offspring, 20% of the offspring were attributable to extra-pair fertilizations (EPFs). Forty-one percent of the 34 males were cuckolded; however, large-badged males were as likely to be cuckolded as small-badged males. Moreover, we found no evidence that large-badged males were inherently superior to small-badged males in terms of survivorship. We compared the prevalence of unhatched eggs in broods with and without extra-pair offspring to determine whether EPFs are associated with hatching failure. Although we detected no association between hatch failure and EPFs, enhanced fertility remains a plausible EPC benefit to females, but experimental approaches may be required to evaluate its significance.


2011 ◽  
Vol 35 (1) ◽  
pp. 4-15
Author(s):  
Ian R.K. Stewart ◽  
David F. Westneat

Abstract In many bird species, males possess conspicuous patches of black feathers on their head or breast, the size of which is often positively related to their success in intra- and intersexual interactions. The production of these plumage signals is presumed to depend upon one or more limiting factors which prevent low quality males developing large signals in order to gain the associated benefits. The coloration of these feathers is due to their infusion with the pigment melanin, which birds synthesize endogenously during a series of conversion steps beginning with the enzymatic oxidation of the amino acid tyrosine. Copper is the cofactor of the enzyme responsible for this process, and it is possible that copper level limits the activity of the enzyme and therefore limits melanin production. We tested this hypothesis by manipulating the level of dietary copper available to individually caged juvenile and adult house sparrows (Passer domesticus) throughout their moult. Birds were provided with artificial diets containing either 100%, 50% or 10% of the recommended level of copper. Dietary copper did not affect the size of the black breast patch, the most obvious melanin-based plumage trait in this species, nor did it affect the reflectance of the black feathers. In sum, we reject the hypothesis that dietary copper limits the size or blackness of the breast patch of the male house sparrow.


2006 ◽  
Vol 84 (7) ◽  
pp. 974-980 ◽  
Author(s):  
A.I. Echeverría ◽  
Aldo Iván Vassallo ◽  
J.P. Isacch

Suburban areas in the Pampas region of Argentina are inhabited by several bird species that sharply differ in their ability to exploit human-modified, urban areas. This bird assemblage includes species restricted to natural grasslands (e.g., Great Pampa Finch, Embernagra platensis (J.F. Gmelin, 1789)) as well as generalist, highly cosmopolitan species such as House Sparrow, Passer domesticus (L., 1758). We explored the role of certain aversive responses to novelty in shaping the marked differences in ecological plasticity among species in the assemblage. In field experiments, we tested for differences in feeding in the presence of artificial objects near feeders regularly replenished with seeds. In spite of their granivorous diet, some non-urbanized species did not use the feeders, possibly because of an extreme degree of aversion to novel situations. The group of birds that visited the feeders included both urbanized (N = 8) and non-urbanized (N = 2) species. We found that the presence of novel objects discouraged visitation to an otherwise attractive food source, although neophobia was weak for most species. However, we found unexpectedly high levels of neophobia in highly generalist, urbanized species such as House Sparrow and Shiny Cowbird, Molothrus bonariensis (J.F. Gmelin, 1789). This response is discussed in the context of the influence of post-fledging development in a relatively simple and predictable ecosystem versus that in urban areas.


2014 ◽  
Vol 60 (4) ◽  
pp. 449-459 ◽  
Author(s):  
Charlène Leloutre ◽  
Alice Gouzerh ◽  
Frédéric Angelier

Abstract Contrary to the nestling phase, the post-fledging phase has been less studied probably because it is challenging to follow the chicks after they fledge. However, this phase is crucial to consider when focusing on the life cycle of individuals because it is associated with new demands: After leaving the nest, individuals have to find their own food and cope with a new set of previously unknown stressors. In this study, we aimed at better understanding how energetically demanding the post-fledging period is in house sparrows Passer domesticus by measuring several indices of a fledgling’s state (body condition, fat and muscle scores and plumage quality). If the energetic demands of the post-fledging period are greater than those of the adult life, we predicted that fledglings should be in lower condition and should have a plumage of lower quality relative to adults. Supporting this prediction, the condition and the plumage of fledglings differed dramatically from those of adults. Interestingly, this difference disappeared in autumn. Overall, our results suggest that the post-fledging period is probably one of the most energetically demanding of the life cycle in this species. Supporting this idea, the resighting probability of fledglings was lower relative to adults. However, resighting probability depends on many factors (mortality, dispersal, habitat use and behaviours) and future studies are necessary to tease apart their relative importance in determining resighting probability [Current Zoology 60 (4): 449–459, 2014].


2021 ◽  
Author(s):  
Anukul Nath ◽  
Hilloljyoti Singha ◽  
Bibhuti Prasad Lahkar

Abstract The persisting growth of wireless telecommunication technology causes increased electrosmog. Exposure to wide-ranging radiofrequency electromagnetic fields is thought to be a concern for all the living species across the globe. Studies have shown possible effects of electromagnetic radiation on various organisms including electromagnetic radiation risk on birds, but the outcomes were inconsistent. Here, we investigated if there is any impact of electromagnetic radiation on the abundance and habitat use of sympatric House Sparrow and Tree Sparrow in Guwahati City, India. In addition, we did a comparative analysis of previous work that had been conducted on possible effects of EMR on wild birds in field condition. We collected sparrow abundance in selected urbanization gradients temporally over a period of two years in 45 locations and spatially covering 168 locations in the eastern part of Guwahati City. Point counts were carried out, and successively we measured the electromagnetic radiation along with other ecological covariates. It was observed that ecological variables contributed significant variation to explain the habitat use of sparrows in Guwahati City compared to electromagnetic radiation. We observed that House Sparrow had quadratic relationship and Tree sparrow had negative association with increasing urbanization. Studies carried out in the past on the impacts of electromagnetic radiation on birds outside the lab condition had not considered other ecological covariates, which could also influence the life history needs of the bird species. Our study emphasized that the ecological covariates should be taken into consideration while studying the effect of electromagnetic radiation on wild organisms.


2006 ◽  
Vol 274 (1608) ◽  
pp. 391-397 ◽  
Author(s):  
Ádám Zoltán Lendvai ◽  
Mathieu Giraudeau ◽  
Olivier Chastel

The stress response is highly variable among individuals, but the causes of this variation remain largely unknown. In response to stressors, vertebrates secrete elevated levels of glucocorticoids which enhance survival, but concurrently interfere with reproduction. We tested the hypothesis that individuals flexibly modulate their stress response with respect to the reproductive value of their brood in free-living house sparrows ( Passer domesticus ). We experimentally increased or decreased clutch size during the nestling period and found that parents tending enlarged clutches responded less strongly to a stressor than those tending reduced clutches. In addition, we examined whether individuals responded less strongly to a stressor as the breeding season progressed and future reproductive opportunities declined. We found that the stress response decreased with breeding date during the birds' first breeding attempt, but it remained constant during their second breeding attempt. Within-individual variability in the stress response was related to the brood size manipulations the birds received in their two consecutive breeding attempts. These results provide the first experimental support for the hypothesis that individuals actively modulate their stress response with respect to the value of current reproduction.


Sign in / Sign up

Export Citation Format

Share Document