Avian Conservation - Make way for the birds!

How many of us have collided against an object, such as a pole/door/mirror before? If you haven't, then you're either a ghost, or probably lying! Most of us should know that colliding with hard objects can be painful or even dangerous. The same applies for migrating birds, with avian obstacle collision becoming more frequent as countries construct even more towering skyscrapers and wind turbines that will look impressive and grand. Based on how frequently they're built, the main forms of obstacles that compete for air space with birds are airplanes, power lines, fences, communication wires, tall buildings and wind turbines (I'll be focusing more on power lines and wind turbines).

Power Lines

POWER LINES POSE A HAZARD TO BIRDS. PHOTO: MIKE FISHER

Many countries choose to construct power lines above the ground and not underground, as it is much cheaper. This is exacerbated by the increase in energy demands over the years, triggering the construction of numerous power lines. However, these power lines can be dangerous to birds, not just in collision, but also in electrocution. Power lines attract birds like eagles and hawks as they provide a prime spot for them to rest and spot their prey. A bird with a large wingspan might make contact with two power lines, resulting in electrical transmission through the bird, causing electrocution and more often than not, death. An example of a bird vulnerable to collision and electrocution is the Bald Eagle, formerly on the brink of extinction, but later removed from the US' list of endangered species after conservation efforts were introduced to increase its population. Even so, the US' Bald and Golden Eagle Protection Act is still in place, and technically, the unintentional deaths of Bald Eagles due to collision or electrocution should require a permit (US Fish and Wildlife Services, 2010). The Bald Eagle is just one of the many types of birds that may unwittingly and unintentionally get caught or collide into power lines, especially when the lines are not easily visible.

Wind Turbines

AVIAN COLLISION. PHOTO: JAMES-MCWILLIAMS.COM

Harnessing wind energy is thought to be a great environmentally-friendly alternative source of energy. To maximise wind energy harnessed, the wind turbines are constructed as high as possible, piercing the open airspace and standing out from the rest of the surrounding vegetation. Unfortunately, this makes wind turbines a major threat to birds. When the blades spin at high speed, there is a "blurring" effect, and the wind turbine blades are not really visible anymore. Statistics by the American Bird Conservancy (American Bird Conservancy, n.d.) indicated that in the US alone, there were an estimate of 573,000 bird deaths from wind turbines in 2012. Thus, this is no light matter, and there are rooms for improvements, which will be mentioned later.

Shouldn't birds see what's ahead and avoid any form of obstacles?
This was the first question that popped into my head, so I did a bit of research and found some really interesting articles. Do read - Article 1. Article 2. Both discussed reasons behind the tendency of birds to collide with tall structures. Basically, simply looking at something doesn't necessarily mean you'll see something. Factors such as weather, food availability and behavioral activity influence rate of mortality of some birds. In addition, birds tend to look downwards when in flight to search for food below and hence, may not be aware or note the oncoming structure blocking its path (Martin, 2011).

What about in Singapore?
In Singapore, most of our power lines are built underground, so that is not too much of a problem. Rather, it is the skyscrapers in the Central Business District (CBD) area and high-rise Housing Development Board (HDB) flats that may cause potential problems. However, research papers on the frequency or rate of mortality when birds collide into man-made structures built in Singapore have been extremely few. As I had the intention to blog on this topic weeks ago, there was scarcely any information in the Singapore context. It was much later that The Straits Times (dated 13 October 2014) reported on this issue, and mentioned how The Nature Society (Singapore) intends to collect information to compile data and determine how many birds on average, die because of collision with skyscrapers in Singapore. (Read it here.) To quote the group, they said that this phenomenon is "chronically understudied" in Singapore, and I couldn't agree more. Maybe more field studies can be conducted in this area?
 

PICTURE OF THE NEWSPAPER ARTICLE WHICH I READ.

Solutions?
-Research have shown that it is better to divert birds away from high-rise buildings and objects rather than make these objects more conspicuous (Martin, 2011)
-Areas with high densities of birds or key bird habitats (either due to high availability of food and shelter) should be clear of any form of potentially dangerous tall objects such as wind turbines and power lines.
- Visual markers or warning signals should be constructed to discourage and induce birds to avoid flying into the vicinity of power lines or wind turbines. Admittedly, this may be a complicated solution as the type of warning signal is difficult to determine, with different behavioral responses for different types of birds.
- The preferred choice would be to built power transmission lines underground, but alternately, insulating cases can be placed around these wires to minimize the risks of electrocution of birds.
-More field studies and research should be carried out to study how avian collision can affect population of birds, especially the endangered ones.

Ultimately, I doubt there is a single, most effective way in minimising avian collision. The mitigating strategies used would have to be tailored to suit the relevant bird species involved, and the type of surroundings.

Literature Citied

American Bird Conservancy. (n.d.) Birds and Collisions. [ONLINE]. Available at: http://www.abcbirds.org/abcprograms/policy/collisions/ [Accessed 10 October 2014].
Martin, G. R. (2011) Understanding bird collisions with man‐made objects: a sensory ecology approach. Ibis, 153(2), 239-254.
US Fish and Wildlife Service. (2010) Eagle Collision Risk Assessment. [ONLINE]. Available at: http://www.fws.gov/midwest/twincities/cpa/capx/pdf/FWS_Collision%20Risk%20AssessmentJune2010.pdf [Accessed 10 October 2014].