Thursday, January 9, 2014

Pilot Study

My bird research is still going on. I thought I would test all 12 of my potential mitigation measures this year but time is not on my side. 

I chose to test only two of the methods, artificial trees and fake poles. They will both act as alternative nesting structure for the birds as opposed to real powerlines. 

I will spend the nest 6 weeks in the field doing a pilot study that will determine the design and plan for the main study. The pilot study will:
  • Find out whether or not the species under the study are territorial birds. 
  • Assess the vegetation around the area where the birds' populations are highest, since I hypothesize that the reason birds nest on powerlines is because there is a lack of suitable trees. 
  • Find out distances between nests in order to determine the extent of intra- and inter-specific competition. 
The result will then tell me in what manner I should plant dummy trees and poles in the field during the main study.

See images below for a dummy tree and dummy poles respectively.



Potential Mitigation Measures

The following are possible methods that I identified as mitigation measure for birds nesting on power linesand and a brief explanation why the methods were chosen as:


1. Dummy snakes

I found no other enemy of the Sociable Weaver to be more influential in the bird’s nesting behaviours than snakes. The study therefore assumes that any other scare device (such as scare crows) will be less effective compared to dummy snakes.


2. Artificial trees and Fake poles/pylons
One of the crucial factors in nest construction is the ability of the structure to support the nest. Therefore providing alternative support structures, such as artificial trees or fake poles, may reduce nesting on electrical poles and pylons.

3. Relocation of nests
In this case nests are moved away from distribution wires where they may pose a threat to power distribution, to the less sensitive parts of the poles/pylons. Relocation may also be from power lines to other support structures available/provided.

4. Anti-nesting devices
A Spanish electricity distribution company, Red Electrica, and a French one called Electricité de France (EDF) tested 7 different devices selected as anti-nesting devices on cat-head type pylons. Some proved to be best as ant-nesting devices (such as the T-shaped, crossed and parallel designs).

5. Reflective features or Laser beam technology
Reflective features include any device with an intense sunlight reflective surface (a nuisance to the birds) that is small enough to be fitted on and/or around electrical structures as anti-perching devices. These can be made at home or from recycled materials and are probably the cheapest option. Good examples would be CDs, cans and aluminium foil.

6. Bird control chemicals
The study identified four chemicals that can be possibly used to rid birds from poles and substations. These are 4-nitropyridine-N-oxide (Avitrol 100) or 4-aminopyridine (Avitrol 200), Methiocarb, Fenthion and Methyl anthranilate (MA). Although some of the above chemicals were proved to be naturally occuring and/or non-toxic, all chemicals shall be used with caution.

7. Other measures (least recommended)
     i. Bird deterrent fog/haze devices
     ii. Netting
     iii. Sticky gums or jells
     iv. Ultrasonic devices