Owl & Poisons Awareness Campaign

by Boudewyn van der Lecq | Jan 20, 2022 | Awareness Campaign, Owl, Poisons

Introduction: Since the establishment of Raptor Conservation Projects in January 2000, numerous projects have been established that includes the monitoring and conservation of large birds of prey species within our urban, rural and agricultural environment.

A subsequent niche has been established, which requires the need to explore avenues to promote owl awareness amongst the farming community by means of our successful owl nest box implementation.

Objectives:

To create and implement an awareness programme amongst farmers through the introduction of Barn Owl and Spotted Eagle-owl as biological pest control agents.

Bio-control is the managed use of one organism to limit the numbers or spread of another. In concept, it is a better way of controlling pests or weeds because it pits predators or parasites against prey or hosts, and relies on the natural impact of one or the other to reduce the scale of an undesired imbalance. The owl bio-control concept is a much simpler and less risky approach to pest management.

In farming areas with pest rodent problems, Barn Owl numbers can be increased by providing suitable nest boxes, spread evenly over the farmland, for occupation and use by breeding owls. Once in residence, the owls will hugely increase the levels of predation pressure on the nocturnal rodent population, and reduce the rodent pest factor in the area both by killing and eating large numbers of rats and mice and by limiting the extent to which the remaining rodents are prepared to venture away from protective cover.

Overall, using owls to control rodent damage is twice as effective as using poison, and much less expensive in the long-term. An optimal array of owl nest boxes in an area requires about one box per 20 ha of cropland, with each box spaced at least 400m from its nearest neighbour. Most importantly, the Barn Owl and nest box approach avoids the severe and systemic environmental costs of repeated doses of toxins: other rodent predators are unaffected, properties remain ecologically functional, and farmland is left healthy and productive.

Problems faced by owls in the wild Barn- and Spotted Eagle-owl Facts Habitat loss:

Due to the change in farming practices and the loss or conversion of many barns that were once used by Barn and Spotted Eagle-Owls. It is an offence to disturb nesting owls and all owls are protected by law.

Increase in road traffic and large motorways: The biggest cause of death for most of our owls especially the Barn Owl and Spotted Eagle-Owl that frequently hunt on the grass verges by the side of our roads.

Poisons through the food chain: Owls live mainly on small rodents some of which will have eaten poison; this is a problem for owls living on farms and in towns and cities where poisons are used to combat rats and mice.

Drowning: Farm reservoirs that are half full causes drowning, owls have feathers that soak up water very quickly and they become waterlogged.

Electrocution: Owls sometimes collide with power lines that maim or are cause of fatalities.

Unnatural collisions: Drivers throw garbage out of vehicle windows and trucks spill grain on the road. Predators such as owls follow their prey to the roadside, often with deadly consequences. Fences can be dangerous as the thin strands of barbed wire are less visible to flying owls and cause collisions getting caught in the barbs, dying slow deaths through thirst, starvation and shock.

Predators: Larger birds of prey will take owls as do jackal and caracal.

Q and A

Q. What is the primary food of the Barn Owl and Spotted Eagle-Owl?

A. the Barn Owl eats mainly small rodents (75-97%) also eats geckos, scorpions, bats, frogs, lizards and termites. The Spotted Eagle-Owl mostly eats grasshoppers, locusts, crickets, beetles, bats, snails, crabs, millipedes and snakes.

Q. How many rodents do Barn Owls consume per night?

A. Usually 6 rodents per night, equalling about 1/3 of their total body weight.

Q. What time of night are owls most active?

A. Most hunting is done before midnight, with a second hunting period beginning about 2 hours before sunrise.

Q. Do owls hunt during the day?

A. Rarely, they are a strictly nocturnal species by nature.

Q. Where do Barn Owls nest?

A. Most natural nests are in tree cavities, in caves, wells, cliff-banked holes, barns, buildings, hay bales and man-made nest boxes.

Q. How many eggs do Barn Owls and Spotted Eagle-owls lay?

A. Barn owls usually 5, but sometimes 10 or more. Spotted Eagle-owls 1 to 5, usually 2 to 3 rarely 5.

Q. What should I do if I find an owlet on the ground?

A. Generally, all owlets fall out of the nest before they can fly adequately, they should be left alone as the adults will look out and feed them. If an owlet is injured, call your local vet or wildlife authority. At no time can you legally keep or care for an injured owl without a special permit.

Owls at Risk

by admin@battyeagleman.com | Nov 14, 2021 | Awareness Campaign, Poisons, Uncategorized

by Anthony Stidolph

The danger of using rat poison was brought home forcefully to a local Richmond egg farmer recently when he discovered one of his resident Barn Owls dead.

According to Graham Willson of Woodlands farm, he had been obliged to set the baited rat traps to comply with the South African Food Safety and Inspection Services Regulations (SAFSIS), which stipulate that these measures must be taken if he wishes to sell eggs to supermarkets. He said he had been assured by the pest control company that had laid the bait that the poison used (Finale) was relatively safe.

An autopsy conducted by the Allerton Laboratory of the KwaZulu-Natal Agriculture, Environmental Affairs and Rural Development subsequently confirmed Willson’s initial suspicion that the bird had indeed died as a result of ingesting rat poison. It listed, among other symptoms, multiple ruptures of the liver, severe segmental intestinal haemorrhage and severely congested muscle tissue and kidneys. The rat itself was found, still in a partially digested state, in the owl’s gizzard.

When Willson confronted the company that had placed the poison bait with these results, it conceded that perhaps it should have used Racumin, a product that greatly reduces the risk of secondary poisoning of no target animals.

Since owls can play a very important role in rodent management, Willson’s feelings are that the measures stipulated in terms of the regulations could be counterproductive, especially since he did not have a rat problem in the first place (he also keeps cats for this purpose).

He pointed out that other relatively harmless species, such as ordinary field mice, could be lured out of their natural habitat by the poison bait and in turn also be fed upon by owls. He felt that the regulations are too rigid and that natural forms of control, which do not impact negatively on the environment, should be both encouraged and allowed.

Pam Stuckenberg of the Merrivale-based Centre for the Rehabilitation of Wildlife (Crow) said she was not surprised to hear of this incident as this sort of poisoning has become increasingly common with results that “are horrible to see”.

What concerns her are that many of the more dangerous rat poisons are freely available over the counter despite the fact that they do pose a risk of secondary and primary poisoning to nontarget animals such as dogs, cats, wild animals and humans (especially children). If a rat poison has to be used she strongly recommends the use of one of the less harmful types such as Racumin (see sidebar).

Ben Hoffman of the Africa Bird of Prey Sanctuary near Camperdown confirmed her views, saying that the poisoning of owls has become a huge problem and that in the vast majority of cases the affected bird would have died long before it made it to a vet or a rehabilitation centre such as his.

He said that in the case of Warfarin-based products, the poisons work by thinning the animal’s blood and causing internal bleeding. This in turn makes them thirsty and extremely slow moving, making them easy prey not only for owls but other raptors such as Crowned Eagles and African Goshawks.

Because of the dangers their products posed, he felt the pesticide companies need to become far more environmentally aware and advise their clients to use the most bio- friendly products.

Like Stuckenberg he was concerned about the easy availability of rat poisons such as Finale and Rattex. People needed to become more responsible and think about the long-term consequences of using poison bait. If traps have to be used he said the old-fashioned rat trap, utilising a mixture of brown bread and peanut butter as bait, is the most effective in that it is target specific and environmentally friendly.

A strong advocate of natural forms of control, Hoffman said that owls play a very important role in rodent management. Research in the United Kingdom has shown that a pair of Barn Owls can kill and consume between 1 000 to 2 000 rats a year.

In Malaya, a government-backed programme encouraging the use of Barn Owls had led to the virtual elimination of the rodent problem in the country’s palm oil industry. Closer to home Sappi has stopped using poison on their seedlings and started erecting posts so that owls have vantage points to hunt from.

An Urban Owl Project has also been initiated to encourage owls and stop the use of poisons. Owls can be lured into gardens and onto industrial premises and farms by erecting owl nesting boxes. Rehabilitated owls are also being released on user-friendly farms. He encouraged anybody interested in either buying or building their own owl box to go onto the Internet or make use of his website.

Using Rodenticides

Dr Gerhard H. Verdoorn of Griffon Agrochemical-Enviromental Consultants said rodenticides should be used with great circumspection as they do pose a risk of secondary and primary poisoning to non-target animals such as domestic dogs and cats, and wild animals. Here are some important aspects of rodenticide application.

Products with the lowest risk of secondary poisoning should be applied. In terms of the anti-coagulant rodenticides, only four first-generation anti-coagulants (in order of preference) are available in South Africa.

a) Coumatetralyl.

b) Chlorophacinone.

c) Warfarin.

d) Diphacinone.

The least harmful (and least risk of secondary poisoning to birds) according to Verdoon’s information is coumatetralyl (trade name Racumin). The avian toxicity of coumatetralyl is low and thus there is strong reason to believe that the risk of poisoning to avian predators is insignificant. A target animal has to ingest the product at least three days in succession before the toxin will manifest in toxic symptoms. It means that an owl that eats a dead rat has a very limited risk of suffering secondary poisoning.

Second-generation rodenticides pose a great risk of secondary poisoning if owls or other animals eat dead or dying rodents. Active ingredients such as difethialone and bromadiolone are second-generation rodenticides. His advice is rather to use first-generation products due to the reduced risk of secondary poisoning.

There is no environmentally friendly rodenticide on the market. They all pose a risk but the first generation are less hazardous.

One could also try EcoMouse or EcoRat that is distributed by Efekto. It contains alpha-cellulose and blocks an animal’s intestines, resulting in internal infections and mortality.

It is very important to observe all instructions on labels of all rodenticides.

Beware of poison

by admin@battyeagleman.com | Nov 11, 2021 | Awareness Campaign, Poisons

Surveys indicate that many poisonings are deliberate, either for human consumption or because birds are perceived to be pests that damage crops and kill livestock. Countless cranes, vultures, raptors and garden birds are however poisoned without ever being eaten, and sometimes without the poisoner having any knowledge of the bird’s presence. Here it is the abuse and misuse of poisons that causes the environmental damage. An outline on how raptors are affected by poisons in South Africa follows:

Deliberate poisoning

Eagles are reviled by some farmers because they are capable of killing lambs and goat kids. These birds can cause real damage to a small-stock farmer if the stock is not managed carefully, and poison is an apparently easy solution. Deliberate poisoning however does isolated units, but instead are components of a not solve the problem for the farmer. When a resident predator is killed, a niche is created, giving inexperienced raptors and other predators, which are more likely to attack livestock, an opportunity to hunt. Vultures, sometimes tarred with the same brush as eagles, are particularly vulnerable to the deliberate poisoning of carcasses. They flock around a carcass in large numbers, and subsequently there are occasions when many die during a single poisoning incident.

Accidental poisonings of untargeted species

Even in urban areas birds are at risk of accidental poisoning. In the average suburban house, rats often find an opportune home with and abundance of food, water and shelter. Spotted Eagle-Owls are well adapted to these surroundings, finding the readily available prey equally opportune. Using a rodenticide that can cause secondary poisoning owls will eliminate of the few natural pest control agents left in the suburbs.

Poison misuse

Humans, creative resourceful by nature, are always trying to find quicker, better, faster ways to cope with their problems. Logic says that if a pesticide and water mixture of 1:3, for example, works well, then a ratio of 2:3 will work even better. This rationale is often applied with dire consequences for the environment, when an overdose kills far more than the intended species, or contaminates the environment, with long-term negative effects. The golden rule for using any poison is to apply it strictly according to the label. In fact, not doing so is prohibited by law under the Fertilizers, Farm Feeds, Agricultural Remedies and Stock Remedies Act, 1947 (Act No. 36 of 1947). Fortunately, the Act also states that the product should be clearly labelled. The label must contain information about, amongst others: the toxicity group, the purpose for which the product is registered, the batch number and registration date, and clear instructions for use. The Act can be viewed on the Department of Agriculture’s website at http://www.nda.agric.za. While death is perhaps just a part of life, the impact that poison abuse and misuse has on raptors is unsustainable. Landowners are critical to the prevention of bird poisonings, as agricultural land and private game reserves support large numbers of wild birds. Urban pesticide misuse and abuse can however also threaten birds such as Barn Owls and Peregrine Falcons. Suburban gardens are not solution. When a much bigger ecosystem that is able to support a resident predator is killed, a niche is created, healthy wild bird population. Thus each individual giving inexperienced raptors and other predators, which landowner and homeowner can contribute to the health of the environment. The golden rule when using pesticides remains: use it only as directed on the label, use it only for the purpose for which it was intended, and use it only as a last resort.

Text by Hayley Komen

For further information:

Please contact the Birds of Prey Programme

Endangered Wildlife Trust

Private Bag X11, Modderfontein, 1645, South Africa

Telephone: +27 11 372 3600

Fax: +27 11 608 4682