Author(s):
Sakraoui D*, Ziane N, Ghalem R, Boukheroufa M, Habbachi W.
* Badji Mokhtar University, Annaba, 23000.
Algeria
Published in:
Biosyst Divers 2023; 31 (4): 493-798
Published: 07.11.2023
on EMF:data since 11.11.2024
Further publications: Studie gefördert durch:

Ministry of Higher Education and Scientific Research of Algeria (MESRS) and the General Directorate for Scientific Research and Technological Development (DGRSDT: PRFU project Code: D00L02UN230120220003).

Keywords for this study:
Effects on animals  |  Fertility, reproduction
Medical/biological studies
Go to EMF:data assessment

Is there an effect of electromagnetic waves from base stations on the breeding success of Ciconia ciconia in Algeria?

Original Abstract

New nest supports used by the white stork Ciconia ciconia (Linnaeus, 1775) are mobile phone network relay antennas, which are not without danger because they emit electromagnetic waves that can have a major, although insidious, impact on the species. The aim of this study is to assess the effects of electromagnetic waves from mobile phone network base stations on white stork reproduction. We monitored the breeding phenology of the storks as a function of the distance of their nests from the base stations over 2 consecutive seasons, 2020 and 2021. The work took place in the North-East of Algeria, in Annaba and El-Tarf provinces. The nests were counted and divided into 3 distinct groups. The first is located on the relay antennae, the second less than 200 m and the third more than 300 m from the antennae. We calculated nest occupancy, number of young in the nest and number of nests without young. The results show that nests located directly on base stations have a reduced clutch size, not exceeding two storks and a low reproductive success since the majority of nests (51.9%) remained without young. The number of young storks tends to increase in nests far from base stations. Broods with 3 and 4 young are generally those located more than 300 m from relay antennas.

Keywords

white stork | mobile phone masts | reproduction | electromagnetic waves

Exposure:

Mobile phone base station, BTS

EMF:data assessment

Summary

Numerous laboratory studies have shown the harmful effects of radiofrequency waves on physiological processes in humans and on animal health. These studies have mostly been conducted in the laboratory, where all parameters can be controlled, but field work is more complex and involves methodological and technical difficulties. Experiments to study the effects of electromagnetic radiation on living organisms are complex because of the large number of variables that need to be controlled. The complexity of this control makes it difficult to achieve the "identical conditions" required for replication. Birds have been used extensively to analyze the environmental significance of exposure to non-ionizing radiation. Their ability to detect magnetic stimuli has been widely documented. In Algeria, the white stork Ciconia ciconia nests frequently in the Mediterranean region. Storks seem to be an interesting species to study the potential effects of electromagnetic waves from base stations. In the study region, they are the only species besides house sparrows that build their nests directly on base stations and spend a lot of time in the nest. The scientists' aim was to determine whether there is a correlation between exposure to electromagnetic waves emitted by mobile phone base stations and the reproduction rate of white storks.

Source: ElektrosmogReport - Issue 4/2024

Study design and methods

The field observations took place over two consecutive years, 2020 and 2021. The scientists observed the species' eggs and chicks twice a week with binoculars. The stork nests in three districts of Algeria (Ben M'hidi, Dréan, Berrahal) were counted to estimate the white stork population in each location. The observations began with the arrival of the storks and covered the period of nest building and care, as well as the period from egg laying to fledging.

The protocol used to categorize the stork population is a repetition of an earlier study by Balmori (2005), except that here the scientists used three groups (0 m, less than 200 m, more than 300 m) instead of two (−200 m, +300 m).

A total of 140 nests were selected and divided into three groups: G1 consists of nests that are 0 m away from the base stations, i.e. located on the base station (27 nests). G2 consists of nests that are less than 200 m away from the base stations (43 nests). G3 consists of nests that are at least 300 m away from a base station (70 nests).

Results

Number of nestlings: The number of young storks in the nest varied between 0 and 4 per nest at the three sites. Nests without fledglings were located exclusively on the base stations (G1), while nests with 4 fledglings were most frequently found in nests more than 300 meters away from the antennas.

Effects of base stations on breeding success:

In 2020, group G1 (27 nests directly at the base stations) had an average of 0.592 young per nest, with a percentage of 51.9 % of nests without young. Group G2 (43 nests at a distance of less than 200 m from the antennas) had an average of 2.046 young per nest and no nests without young. Group G3 (70 nests at a distance of more than 300 m from the antennas) had an average of 2.8 young per nest and no nests without young.

In 2021, the trends remain similar. Group G1 had an average of 0.814 young per nest, with a percentage of 40.7 % of nests without young. Group G2 had an average of 2.186 young per nest, with no nest without young. Group G3 had an average of 2.87 young per nest and no nests without young.

The results of the paired T-test show no significant difference (P = 0.162) between the years 2020 and 2021. With regard to the average number of young per nest, the analysis of variance (ANOVA) showed a highly significant difference between the three groups (F = 122.21, p < 0.001) for the years 2020 and 2021.

Linear regression analysis between the distance from base stations and the average number of young per nest shows a very highly significant relationship (p < 0.0001).

Conclusions

These results indicate that the proximity of nests to mobile phone base stations influences the reproduction of storks. Nests that are located directly adjacent to the antennas have a very low reproductive success. The further away the nests are from the antennas, the greater the reproductive success, with nests more than 300 m away from the antennas having the highest reproductive success.

These results are consistent with those of Balmori (2005), who studied 60 white stork nests. According to Balmori, 40 % of the 30 nests less than 200 m from a mobile phone base station did not yield any chicks, while in another colony with 30 nests more than 300 m away, only 3.3 % failed to produce to chicks. (AT)