Silent Killer

An increasing number of raptors are exposed and dying from rodenticides, commonly called “rat poison”. Unsuspecting people that wish to control or rid their property of rodents often turn to products, such as D-Con; however, this choice comes at a high price. When the targeted animal eats the poisoned bait, it does not die immediately. This potentially deadly prey animal now runs the risk of being caught and eaten by a non-targeted animal such as a raptor. Raptors that do well in an urban environment, such as Red-tailed Hawks (Buteo jamaicensis) and owls, are at a higher risk.

Companies that manufacture rodenticides try to counteract a bad public image by marketing the product as safe and that the poisoning of non-target animals is rare. Below is a direct response from D-Con’s website to the question of whether the product could poison unintended animals: (http://www.d-conproducts.com/faq/)

The potential of any secondary poisoning depends on what type of pet it is, how big it is, what type of bait it has consumed, as well as how much bait was consumed. If you are concerned about a possible exposure, you may wish to contact your veterinarian or the toll free number located on the package to be directed to appropriate personnel who can address your concerns. Occurrences of this type of poisoning are extremely rare.

They admit that smaller animals are at greater risk. An adult Red-tail weighs two to four pounds and an adult Great Horned Owl (Bubo virginianus) two to three pounds. The preferred prey for these species are small mammals, such as mice and chipmunks, are high targets for rat poison.

Anticoagulant rodenticides (AR) affect the vitamin K-mediated synthesis of blood clotting factors in the liver. The animal eats the poisoned prey and becomes at risk for fatal hemorrhage episode triggered by trauma and/or increased heart rate. Second generation anticoagulant rodenticides (SGAR) stay in the body longer than its first generation, making it more lethal (Stone et al. 2003).

A recent study revealed a high percentage of Red-tails and Great Horned Owl have residual levels of rodenticides stored in their liver (Stansley et al. 2014). The researchers collected liver samples from Red-tailed Hawks and Great Horned Owls in New Jersey. At least one SGAR was detected in 81 % of Red-tailed Hawks and 82 % of Great Horned Owls. The most frequently detected SGAR was brodifacoum, which was detected in 76 % of red-tailed hawks and 73 % of great horned owls. According to ((ABC) 2013)Brodifacoum was made a “restricted use” pesticide in 2008 by EPA, meaning it can only be used by certified pesticide applicators. The manufacturer of D-Con (household brodifacoum) is challenging this decision in court. The product remains on the market for public use.
 Reading between the numbers and statistics, rat poison remains a very real danger for raptors. The bottom line, don’t use them! If you have a rodent problem, put up a barn owl or kestrel nest box on your property. Please visit these websites for information:

Barn Owl Trust

Barn Owl Nesting Box Plans

Kestrel Nest Structures

LITERATURE CITED

(ABC), A. B. C. 2013. Pesticide profile - brodifacoum.

Stansley, W., M. Cummings, D. Vudathala, and L. A. Murphy. 2014. Anitcoagulant rodenticides in Red-tailed Hawks, Buteo jamaicensis, and Great Horned Owls, Bubo viginianus, from New Jersey, USA 2008-2010. Bulletin of Environmental Contamination and Toxicology 92:6-9.

Stone, W. B., J. C. Okoniewski, and J. R. Stedelin. 2003. Anticoagulant rodenticides and raptors: Recent findings from New York, 1998-2001. Bulletin of Environmental Contamination and Toxicology 70:34-40.

Vultures are People too!

I know I have not posted in over four months. I have been on a self-imposed hiatus for the usual reasons; busy. However, the recent onslaught of articles on my Facebook newsfeed about Vultures dying all over the world has compelled me to come out of hiding. If any of you follow my blog or know me, gather I am a “just the scientific facts ma’am” kind of writer but this blog is more emotional with a twist of pleading for global change.

In India, Pakistan and Nepal, by 2006 the vulture population had declined 99%, (yep, you read that correctly). Nearly all the vultures had disappeared due to a veterinary drug called diclofenac. Because of the cultural importance of cattle in this region, aging cattle were given this anti-inflammatory drug to relieve pain. When these cattle died, the carcasses were contaminated with the drug. Vultures began to disappear rapidly. It took almost two decades for researchers to discover that the contaminated carcasses vultures were feeding were killing them by kidney failure; a slow, agonizing death. In 2006, the governments of India, Pakistan and Nepal banned the use of diclofenac. The recovery of vultures is now in full intensity and showing signs of recovery (Balmford 2013). Please see, http://www.peregrinefund.org/projects/asian-vulture-crisis and http://www.save-vultures.org/, to see what is being done for Asian Vultures.

So all is good? Nope, in March 2013, the Spanish government made diclofenac available on the European market. Please see this website to support the ban in Europe and keep updated on the fight, http://www.4vultures.org/our-work/campaigning-to-ban-diclofenac-in-europe/

Diclofenac is not the only threat facing vultures. In Africa, vultures are declining for the same reasons, such as the rhino and elephant, medicinal purposes. Poachers are poisoning, indiscriminately, carcasses in order to collect the dead vultures to sell on the black market. Vulture brains and skulls are believed to provide psychic powers and intelligence (Dimitrova June 24, 2014; Pfeiffer et al. Spring 2014). Africa’s vultures are at risk of suffering the same fate as their Asian counterparts. Go to, http://news.mongabay.com/2014/0624-dimitrova-vulture-bird-market.html, to read the full article.

Vultures are charismatic and intelligent birds as well as play an important role in ecosystems and cultures globally. These birds are often deemed disgusting and do suffer from an image problem (Ravindran 2013); however, vultures are really cool birds! I have known a few vultures in my life and these characters have charmed the average visitor as well as the royalty of Great Britain. So, my plea is wherever you are in the world, do your part to help vultures! Give your time and money to organizations that are fighting for vultures or learn what you can do, as an individual, not to add to the decline of these wonderful birds.

"Delectable" entertains herself at the International Centre for Birds of Prey (www.icbp.org) by handing her feathers to visitors in order to trick them to put their fingers through the wire of her aviary. 

Literature Cited

Balmford, A. 2013. Pollution, politics, and vultures. Science 339.

Dimitrova, T. June 24, 2014. Shot Egyptian vulture leads conservationists to bizarre black-market for bird parts. Environmental News. Mongaybay.com.

Pfeiffer, M., A. Botha, J. Venter, and C. Downs. Spring 2014. Silent slaughter of Africa's Vultures. Pages 24-26. The Wildlife Professional. The Wildlife Society, Bethesda, MD.

Ravindran, S. 2013. "Disgusting bird" is dying off. Scientific American 309:14.