POSITION: 1080 IN PROBLEM ANIMAL CONTROL

M.J. DE WET. DECEMBER 2002

Author has 25 years experience in problem animal work that includes both research and practical control work. Twenty three years in civil service (provincial conservation in the Transvaal and than North West). Presently in the private sector but I own no livestock and do not sell any control equipment or my services for control. I am in the unique situation to have the necessary background and interest to look objectively at the problem at hand without any monetary motives to influence me. Courses can be presented that include all the practical control methods with objective, scientific evaluation of the pro’s and con’s of each, as well as the specific situations under which each can be used. It is stressed that the largest possible variety should be used. This is an important problem animal control principle. The necessity of the correct application of each method is also stressed, and this can only be achieved through proper training.

When we look at a new use or application of a control method there are numerous principles and issues that has been developed over the ages that has to be taken into account. One of the most important being that the purpose of Animal Damage Control (ADC) is stopping or decreasing damage as opposed to the killing of animals. Our damage control methods are still imperfect and not all problems can be solved by electrified fences, shepherds, King collars, live capture, penning animals etc. We often still need to kill to stop damage, but effectivity and selectivity to remove target animals is of the utmost importance. It is crucial that any new method should really be new and that all the lessons learned in the past be incorporated to contribute to solving the present problems.

Hygnstrom (1990) Advocates a systems approach rather than a species approach. In this regard for example: the circumstances of the damage; location of damage; other predators in the system; other prey animals; breeding condition of all animals involved; condition of predator and prey; age of predator and prey; management system in place for livestock; weather conditions etc. etc.  This principle is fully supported and should be advanced as much as possible. Advocating of the use of a poison to kill large numbers of jackal is a step in the wrong direction. Bait that selects only carrion feeding individuals is unacceptable. Control should select damage-causing individuals, or at least have an equal change in killing predatory and carrion feeding individuals.

There is an increasing onslaught from the “Greens” that, through emotionalism and lack of knowledge, but with millions of dollars behind them can cause serious problem in the problem animal world. The best way to counter the attack by the “Greens” is by gaining knowledge and extending this knowledge to the public as widely as possible (Timm & Schemnitz 1988). Professional attitude and using the best, most humane and selective methods of solving animal/man conflict must be stressed (Brooks 1988). Continuos striving to better solutions of ADC problems is imperative (Miller 1988). Professionalizing and standardizing training is also very important (Timm 1982).

HISTORY

Bounty has been paid since 1656 for the killing of vermin. The fight against predators was mainly driven by individuals. Roberts (1922) documented 50 000 jackals killed during 1920 in the Cape Province alone. The development of a hunt club system then contributed to more organized eradication of predators. During 1929 the Free State had 550 Jackal clubs with 10 000 members and about the same number of tax-free dogs – only 2 000 jackals were killed during that year (Cattrick 1950).

During the later part of the nineteen twenties vermin proof fencing was erected for over 15 000km in borders and camps for vermin control in the Cape Province alone. Despite this bounty for 26 237 jackal was paid during 1949 (Bigalke 1951).

The numbers of 400-700 killed on average between the mid 1960s and early 1980s in the Free State compare poorly to this especially when considering the aim at that stage was the attempted eradication of the jackal.

During 1953 a operation was carried out where ±1 000 men were involved between Wolmeransstad and Makwassie. This was mainly by a number of drivers, on foot and horseback, and a number of shots that ambushed the jackal. The operation lasted two days and was supposed to clear a large area of jackal. Only 31 jackal was killed.

It should be clear to anyone experienced in the problem animal field that the scale of killing tens of thousands of animals killed in each province each year, as have happened during the past, is impossible to repeat for many practical and economic reasons. There are many biological reasons why large-scale eradication cannot work and clear indications of very detrimental and counterproductive results from attempted eradication exist.

Sampson & Bennit (1947) compared the success and economics of four systems (bounty, government trappers, state trappers with dogs and extension trapper training) in use in the state of Missouri in the USA. They concluded that the extension training enabled landowners themselves to act promptly and to be more likely to remove the killers. It was rated the “cheapest and most immediately effective method yet devised.”

History gives us a clear message on the control of damage to livestock – we cannot eradicate the jackal or the caracal. The strategy indicated to us is a concentrated attack on damage causing individuals within the damage causing species.

LEARNING, AVOIDANCE AND SELECTION PRESSURE

Jackals have a phenomenal learning and breeding capacity. The learning process is expedited by the fact that in adult jackal the social unit is a male/female pair. The animals forage and defend their territory together. When one individual gets killed by whatever method, the survivor witnesses the demise of its mate and avoids being trapped by the same method. (Roberts 1922, 1951; Van der Merwe 1953; Editorial in The Woolgrower Feb. 1955; Howard et al 1977; Ferguson et al 1983; McKenzie 1990; Van Rensburg & De Wet 1995).

A male jackal will raise his offspring alone, once they are weaned, even if the female is killed. Both parents teach young to avoid dangerous objects and situations. If any trap is not set with the utmost care to detail, position, smell, lure, wind direction etc. the jackal often escapes the attempt and will thereafter be so much the wiser. It is imperative that only top quality equipment be used.

This implies that no bait will keep being effective over time and any success will be of temporary nature.

During the late fifties the term “Neophobia” was coined to describe the suspicion/fear for unfamiliar objects by animals (Barnette 1958). Bacon (1985) describes the same phenomenon and coined the phrase “novel bait item.” Dependant on the aim of control work, this has far reaching implications, the most important being the long term selection pressure with negative results to the livestock industry. This will result in us expecting more problems and increased difficulty in solving problems. It is recommended that we should rather follow a strategy of long term improvement of the problem.

Jackal refused to enter capture cage for food even after 8 days of starvation (pers.obs.). The animal would rather die of starvation than enter the cage. Howard & Marsh (undated) found that “Some rats, after being fed wheat with a toxicant on it, will starve before eating even clean wheat.” Smith (1978) found that foxes, in England, quickly learn to avoid control methods and that human caused mortality only replaced natural mortality, rather than adding to it.

Below, follows a few quotes to illustrate that the above phenomena were known even 80 years ago. Both authors description follow questionnaires to farmers and a synopsis of farmer knowledge:

·         Roberts (1922) “...precautions against raising suspicion...”; “...carry poisoned bait for some distance then drop it.”; “...affects of sex and age on usefulness of poison.”

·         Roberts (1951) “...supreme cunning in eluding capture or destruction by farmers,”; “...disgorges poison baits.”

·         Van der Merwe (1953) “...pick up poison bait, carry it for some distance and then drop it...”; “...teach their cubs to avoid poison bait.” “The knife and stick which are used for putting in poison, should be inserted in warm dung for a few minutes before use,...” “As has been stated, persons setting out poison, should bear in mind that when dealing with a sheep killing black-backed jackal this would be in vain,...”

THREE SUCCESSIVE POISONING PROGRAMS (PELLETS) IN THE AREA NORTH  OF THE SOUTPANSBERG WITH PROGRESSIVE AVOIDANCE:

       PROGRESSIVE AVOIDANCE OF GETTERS BY JACKAL (BRAND et al 1995)  

Within the jackal population there are clear distinctions between individuals that prefer carrion while some others have a more predatory feeding pattern. The predatory individuals are the problem but the carrion feeding individuals are killed by ordinary poison bait. As sure as farmers breed cattle for earlier adulthood and higher meat production or sheep for denser or finer wool, jackal are bred to catch live prey rather than eat carrion. During intensive poison campaigns a high percentage of carrion feeding individuals are killed and the process is well on its way (Beaudette undated; McIlroy 1992; Palumbi 2001; Twigg et al 2002).

During research on poison use and selectivity it was found that jackal has avoidance for warthog baits. This work was done north of the Soutpansberg. Warthog may not be transported due to swine-fever and therefore are not hunted. This species is therefor expendable and has been used extensively for poisoning campaigns. The response to impala or goat meat was clearly better (Van Rensburg & De Wet 1995)

1080

Burns et al (1991) recorded decrease in intake of meat with 1080 by golden eagles (Aquila chrysaetos) and skunk (Mephitis mephitis), and increased intake in clean meat. Sminthopsis crassicaudata (an Australian marsupial) were conditioned to feed freely on meat in the laboratory, but when they were offered meat poisoned with 1080 their intake was significantly reduced and they vomited. Some of them refused to eat meat altogether even when a choice of poisoned and non-poisoned meat was provided (Sinclair & Bird 1984). Deer mice avoided eating grain with 1080 after sub-lethal dosing (Howard et al 1977). Some animals thus clearly can detect the presence of 1080 in bait and it can be assumed that jackal will be able to as well.

STABILITY OF WATERY SOLUTIONS

There seem to be a misconception about the stability of the poison in watery solution. This may come from authors like Atzert (1971) and Kramer (1987) with statements that 1080 degrades in watery solution. This is a very slow degradation mainly due to micro-organisms. The standard way of applying 1080 to bait in the USA as well in Australia is by dissolving the 1080 in water and injecting meat baits with hypodermic needle from the stock solution. The baits remain poisonous for months and millions of coyotes and rabbits and thousands of dingoes and feral dogs have been poisoned in this way. Toxic collars are also filled by watery solution and under different testing situations, no weakening of the poison was found for more than a year (Robinson 1948, Green 1951; Rudd & Genelly 1956; Meldrum et al 1957; Rowley 1960; Atzert 1971; McBride 1978; Connolly 1980; Hone & Pederson 1980; Sinclair & Bird 1984; McIlroy 1986; Boddicker ??; Burns et al 1988; Connolly & Burns 1990; Green 1992;).

What is worrying actually is the long lifetime of the poison that remains in nature. If the bait dries out it will remain poisonous indefinitely.

The intensive research by McIlroy in Australia and the relative good results are mainly because the “pests” are exotics with a relatively low resistance to 1080. The indigenous animals, however co-evolved with 1080 bearing plants and developed a high resistance to 1080 (McIlroy 1992). In South Africa, however the “pests” has a high resistance. McIlroy et al (1986) came up with various reasons why success with the capture of feral dog was better by gin trap rather than with 1080.

Another big drawback of 1080 is the fact that there is no dependable antidote. This may have serious consequences for humans and non-target animals.

SYMPTOMS OF POISONING

Statements have been made about the symptoms of 1080 poisoning in dogs than resemble heart failure. The literature and research by Nature Conservation contradicts this statement. Symptoms differ through taxonomic groups. In general it seems like herbivores die as if in heart failure. Primates, pigs and cats show symptoms of the effect of the poison on the heart, but also severe convulsions. Dogs, however die from only the convulsions, and death is attributed to asphyxiation when the dog cannot breath due to the convulsions (Clarke et al 1981; Timm 1983)

Another important aspect of 1080 poisoning is the vomiting that that poses a threat to small non-target animals. Various substances have been tested unsuccessfully to prevent vomiting. O’Brien et al (1986) found metocloprimide did not affect the frequency, although the volume of vomitus decreased in feral pigs. Rathore reported success with the same chemical but it did not prevent vomiting in coyotes (Green 1992).

Boddicker? “Relative to strychnine, 1080 takes longer and coyotes experience longer periods of discomfort...”

Insight in this aspect can be gained by transcription of part of one of the data pages of Grafton & Van Rensburg 1962-1964:

Jackal 0.7mg/kg: took poison 14:00.

16.03 Vomited; 16.20 Vomited, reactions acute & very nervous; 16.30 Salivating very heavily; 16.35 Vomited; 16.37 Nervous spasms; 16.50 Heavy breathing and salivating 16.55 Standing erect, very weak & foaming at the mouth; 17.45 Vomited & started shivering; 17.46 Severe convulsions – leapt into air & struck the top of the cage (1.8m) and fell on its right side – extreme convulsions. Try to rise, legs crossing very stiff & shaking – eyes staring – unable to stand. Convulsions of the very worst degree, muscular tremors over entire body – apparent no control over reactions; 17.55 Breathing stopped, stiffening of limbs. Slight convulsions – slow deep breathing commencing; 17.56 Convulsions, unable to rise, limbs stiffening, breathing stopped. Slight muscular tremors; 17.57 Only head and shoulders jerking; 18.00 Very slight tremors, deep breath, stiffening, release & shivering 18.07 Convulsions & breathing stops. Head & shoulders contractions of muscles; 18.08 Deep breaths – convulsions for a few seconds then lying still as if dead; 18.09 No breathing 18.10 Slow breaths – at intervals tightening of muscles hackles rising, lying as if dead.

“Greens” can cause problems – we do not need lies about symptoms and humaneness.

LETHAL DOSE (LD) & DEGRADATION OF 1080 IN THE FIELD

LD Figures quoted is for overseas animals like coyotes and dingoes. However a small series of tests have been done in South Africa and a summery of the results are given in the table below. Southern African animals, like the jackal developed along with 1080 containing plants and have a resistance against the poison resulting in a significantly higher dose necessary to kill them than their overseas counterparts. On the other hand figures quoted for vultures are the opposite. American vultures or condors (Cathartidae) have LDs above 15mg/kg, (Timm ed 1983) but is in a different family than the South African vultures (Accipitridae) Our vultures and almost all the other raptors belong to the Accipitridae. Our vultures are thus closer related to our eagles than to American vultures. Further the other American raptors also belong to the Accipitridae and we share some genera like Buteo and Circus for which the LD is above 10mg/kg. However we also share the genus Aquila, (America A.chrysaetos, Australië A.audax and South Africa A.rapax, A.nipalensis, A.wahlbergi and more), for which the LD is given as 1.25mg/kg.

THE EXTRAPOLATION OF LD VALUES F0R RELATED GROUPS THUS CANNOT BE ACCURATE !

Toxicity of 1080 was found to differ with temperature and situation (from 1.78mg/kg to 2.3mg/kg for magpies) Burns & Connolly (1992). The most extreme found to date comes from Oliver & King (1983) who found a five times higher LD for the house mouse (Mus musculus) at 24°C than at 12°C.  The authors found that extremes of temperature caused the animals to be much more susceptible to the poison. This has huge implications for non-target animals as most of the poisoning will be done at very low temperatures.

McIlroy (1981) demonstrated the effect of stress on LD for 1080 and concluded that some animals are to nervous in captivity for LD tests and to obtain valid figures the animals would have to be radio collard and released in free situation for proper determination of LDs.

       1080 LD FOR SMALL TEST ON JACKAL (Grafton & Van Rensburg 1962-64)

SOME BIRDS THAT FEED ON CARRION THAT WILL DIE FROM THE MINIMUM DOSE OF 1080 FOR A JACKAL (7mg/kg).

  (For caracal the minimum dose is more than 20mg 1080 and practically all raptors would die from this).

Calver et al (1989) stressed that LD figures alone do not indicate risk to non-target animals. other factors to be taken into account is:

·         Size of bait

·         poison content of bait

·         amount of bait eaten

·         tempo of bait consumption (both target and non-target animals)

·         % of population exposed to poison

These authors also use a concept of “approximate lethal dose” (ALD) as alternative for LD₅₀ where the dosage is increased stepwise till the first animals dies. This showed good correlation in studies where ALD and LD₅₀ were both determined. McIlroy & King (1990) used “appropriate amount” based on the LD and degradation of the poison under field conditions.

Various authors showed that some of the 1080 chemically bonds with the meat and then becomes untraceable during analysis (McIlroy 1986; McIlroy et al 1988; O’Brien et al 1988; McIlroy & King 1990).

Korn & Lavinos (1986) showed that the bait preparation technique had a huge influence on the ultimate poison content. The injection of concentrated solution of 1080 was the most constant. Freezing of poisoned baits stopped the biological breakdown of the poison by micro organisms. When the bait is used in the field, the poison is systematically broken down until it is not harmful anymore.

The summery of the properties of 1080 in the article in the February 7th issue of Landbouweekblad should be enough to discourage any use of 1080 outside the toxic collar.

One psychological fact that should never be forgotten is that livestock owners want to see carcasses of dead problem animals. This is unlikely with 1080 due to the lengthy latent period. For the jackal 8-36 hours (Van Rensburg & Grafton 1964). The time lapse for dingo is 9, 4 hours (McIlroy et al 1986)

TOXIC COLLAR

The toxic collar (also filled with 1080) has been thoroughly tested and found to work satisfactory (McBride undated ; US Fish & Wildl.Serv. undated; Connolly1978). The use of the poison collar is supported and as one of the most valuable of control methods of today.

LURES

Lures are chemical and biological substances that attract animals by stimulating their senses. Stimulation could also be negative and deter the animal. The same lure may under different circumstances either attract or deter the animal in different seasons or concentration of the components (Graves 1987). Some lures attract a wide range of animals while others may only attract specific species or even just a specific age or sex group. The reproductive status of and animal can also determine the interaction with a lure. Even temperature and rising or falling in barometric pressure has been found to cause different reactions (Graves 1987). The learning ability also plays a role and previous contact with the lure can cause different reactions (Philips et al 1990; Guthery et al 1984). The expectation to develop a single lure for each kind of animal that has to work over all seasons right through the country thus is unrealistic (Fagre 1983; Philips et al 1990). “It is hardly a matter of surprise that methods found entirely satisfactory in one district fail altogether in another”(Roberts 1922).

Selectivity and effectivity is not only dependant on the lure, but also on the application thereof. Ferguson (1986) pointed out the difference in selectivity between different operators. Robinson (1948) as well as Kalmbach & Linduska (1948) and Guthery & Wyman (1984) stressed that the placements of baits must be away from non-target animals but closer to where only coyotes can be expected. Brunner (1983) “The actual location of the bait material was often more important than bait type in determining uptake.” When all the most important criteria are adhered to, the kind of poison is of lesser importance in selectivity.

A clear distinction is needed between food lures and non-food lures. A poison like 1080 has to be delivered orally and therefore has to be eaten. Food selectivity, however is severely limited. Caracal will take only fresh meat, while jackal would also eat rotten meat. Many other animals will also eat this food.

Selectivity is achieved where specific pheromonal reactions are elicited. Reactions like lick, bite, pick-up & let go, role, scratching, urinating and so on are seen. This does not include eating and swallowing bait (Hein & Andelt 1994).

When testing pheromones in captivity the effect of learned behavior and cage behavior must be taken into account and this can be quite different from the behavior of free roaming animals. For instance Jolly and Jolly (1992) found good correlation for number of stations visited by feral dogs, but little correlation between time to find the lure, time investigating the lure and behavior at the lure. Captive animals seldom would keep reacting the same with repeated test with the same pheromone.

In general it can be accepted that more complex lures would lead to more complex reaction, but the reaction of simpler lures are more constant. For complete results it is needed to test lures during the various seasons before conclusions on reactions are drawn.

Philips et al (1990) promote the use of pheromones for better selectivity. The Transvaal Conservation Department personnel mainly used pheromone bait for coyote getters since the early 1970s. This may be part of the reason why they were more selective than FPBV (Federale probleemdierbestrydinsvereniging)  (Ferguson 1986). This bait causes a pick-up reaction.

Graves (1987) found big differences in between the success of operation of various lures for different equipment (gin, M44, snares)

Colored of baits can play a major role in selectivity as far as non-target birds are concerned. Green blue, and yellow meat are not eaten by birds because they find food by sight, while mammals find food by smell (Bryant et al 1984; Kramer et al 1987; Kleba et al 1985; Kalmbach & Welch 1946; Brunner & Coman 1982; McIlroy et al 1986).

WONDER SOLUTION – SELECTIVITY

To laud 1080, that has been researched and used since the early 1940’s as a new miracle solution is unrealistic. This can only create false hope that will be transformed into realism and lead to loss of faith in the professionality in the problem animal community as a whole. I do not want to be associated with the creation of false expectations. Even if we do find a poison that is 100% selective lures for killing only jackal or caracal or dog and no other species of animal, it will still not solve the problem of damage by the predators to livestock and game.

POPULATION DINAMICS

Simulation models of coyote (very similar to the jackal) predict that coyote populations can indefinitely survive 70% of the population killed annually. When 40-50% is killed yearly, it will still be the habitat that determines the numbers of animals and not the control effort (Connolly 1978). These figures cannot be applied directly to the jackal, but the same kind of process is undoubtedly at work in the jackal. The most important ways through which this resilience operates are: Younger breeding age, higher litter sizes and lower natural mortality. In the short term the immigration of animals from the surrounding area is the main, and very quick way of replacing animals. Thus: The more intensive the control the faster the reproduction – and usually the control is on the wrong individuals to create a process of a breeding program for damage causing, capture resistant predators.

IGNORANCE AND THE NEED FOR EDUCATION AND EXTENTION

Fitzwater (1990) recorded some myths known to have influenced ADC since early history. The myths date from the early 1600s and were based on ignorance. Many thus have disappeared. However when some articles are read, I wonder whether we really progressed since the Dark Ages. Sometimes the symptoms of over-control is described as well as the reaction of the populations. The remedy that is recommended, however is guaranteed to aggravate the situation. It usually includes eradication or serious depression of predator numbers. It is time to displace such myths with proper interpretation of scientific based facts to move forward and make a real difference to solve the problems. 

More should be done on human dimensions in wildlife, especially PAC. Then less poison of any kind would be used in PAC (Gigliotti & Decker 1992)

When extension is done without this basic knowledge more harm than good is often done. Unrealistic expectations are created and ineffective or even harmful control measures results. In any case the problem is not solved. This means that the credibility of all ADC extension is questioned.

Even personnel from the formal conservation sector often underestimate the complexity of ADC. Except for the biological and ecological complexities, each and every control method needs specialized knowledge to operate at its capacity or even effectively. No person should attempt serious ADC extension work without proper training as well as at least 2 years of practical ADC experience. It is too easy to accept bad control methods on face value if the necessary biological knowledge is lacking. In depth knowledge, especially about population dynamics, social structure, learning abilities and ecological processes and possible control methods around the species involved is of the utmost importance. The effects and reaction of populations to control of numbers is especially important when lethal control such as poison becomes involved. The widest possible knowledge about damage control measures and the proper application under different field conditions is also imperative. Extension on poison use without extension on alternative damage control techniques often leads to increase in use and abuse of poison, even if the original extension was well meant.

In his survey of the Natal Woolgrowers, Lawson (1988) found that only 9.5% of participants used poison (out of 11 methods mentioned) as their primary method of control of predator damage. This stresses the balance that should be maintained. When methods such as fences, shepherds, poison collars, management options, shooting, denning, gintraps, getters, to name a few, are not used in favor of poison, the reason often is because the person does not know the proper application of those methods.

Various authors that stresses the professionally of control in relation to sensitive public opinion and human dimensions is Howard (1962), Hygnstrom (1990), Johnson (1990), Jones (1988), Race et al (1991), Reidinger (1990), Richards & Krannich (1991), Thompson (1990), Timm & Schemnitz (1988) & Wywialowski & Reese (1990). Hornocker (1972) "...professionalize control agencies at all levels. Public education, as it relates to predator control, has been inadequate and should be improved. Predator management and not control should be stressed."

High profile advertisement of use of poison may well lead to serious anti-PAC sentiment. This should be avoided (Gentile 1987)

AS MANY CONTROL METHODS AS POSSIBLE

Control methods must differ by lure, mode of action, the way in which the animal detects it, to the extent that avoidance to one will not cause avoidance to all. An animal that survives an attempt with one control method may then still be killed by the other methods. Therefore no aversion would develop. Many scientists and Greens want to scrap methods that seem less than perfect when something that seems to work better comes along (Brown 1985). The truth is we cannot scrap any method that works. Aversion to control methods necessitates a very wide range of methods by which an animal that developed aversion to a few methods could still be controlled by other options. This is why ADC is a dynamic subject and continuos work is needed to ensure acceptable control options. Howard et al (1985) "No single or combination of control methods (such as traps, M-44s, shooting, guard dogs, electric fencing) has been found to protect livestock from coyote predation under varied types of habitat, terrain and husbandry,..."

POISON WORKING GROUP’S PERSPECTIVE

My personal background is from within Nature Conservation and I consider the Endangered Wildlife Trust as an ally in the search for selective and effective solutions to damage by problem animals. There is, unfortunately various points in the quoted document that does not comply with the principles set out in the above document.

Various other methods (than poison) are discussed, all on the pattern of the potential, but that they are often abused and used unethically. The negative aspects are then discussed as the reasons why the method should not be used. The poison discussion, however starts with the fact that poison are seriously abused, but then the positive aspects are discussed, with the conclusion that this is the best method of damage control. This evaluation is supported by two letters in Landbouweekblad of 18/01/02 by Trevor Filmer and Nico Lourens. The impression left by the Poison Working Group is the farmers that use all other control methods unethically, will use poison ethically.

The strategy rather should be to concentrate on the positive aspects and to advance this through training. As explained in this document we cannot afford to drop any potentially successful method. It is imperative that we use as many methods as possible to prevent the long-term deterioration of the problems. If we have to drop good methods because they have been abused, or because some authors do not understand its proper use, then we will have nothing, and poisons, especially baits, will be the first to disappear permanently out of the problem animal system.

A clear distinction in predator populations must be recognized between a) individuals that tend to feed on carrion and do not take live prey and b) individuals that prefer live prey and would only utilize carrion when unsuccessful with the hunt. The last mentioned group contains all the damage causing individuals. Poison bait is eaten as carrion and therefore by definition the wrong section of the population. With the correct use, gintraps, cages, dogs, getters, poison collars, shooting and more, could all be more effective and selective than poison bait.

The average time before a jackal dies from 1080 as ±15 hours. When gintraps are set at dusk and checked at dawn, the period of stress and suffering will be less than for an animal dying from 1080. The time till death with poison like cyanide (from a getter) is only a few minutes, and the symptoms are not nearly as painfull.

Any person experienced in the process of setting a gintrap for jackal, including the care of smell and sight camouflage, will understand that it is unrealistic to expect a method of poison application to work when it is based on a steel peg from which a bait is dangling. The only jackal caught would be young, inexperienced individuals, or old ones that battle to get food. The real damge causing individuals will not be caught in this way (Neophobia).

In tests during 2002 on S.A.Lombard Nature Reserve, Harrison-White (pers.comm) found that captive cape foxes (Vulpes chama) and serval (Felis serval) took this dangling bait much easier than black backed jackal (Canis mesomels) or caracal (Felis caracal). In tests on free living animals no baits were taken by jackal. Various baits were taken by black koraan (Eupodotis afra) and/or crows (Corvus albus). In two instances it seemed like porcupine (Hystrix africaeaustralis) took the bait. The question is what other animals, specially birds will take haning bait, swinging in the breeze. This include: ground hornbills; various koraans, bustards, hornbills, shrikes, drongoes, kites, falcons, coucals, crows. A few of these are red listed and though their LD is not available for 1080, this is as undeniable threat to a whole range of birds.

Currant methods for placing poison bait are to cover the bait under sand or plant material. This can only be detected by smell and thus excludes all birds. Some smaller mammals may however be killed. When the bait is visible (and dangling in the air – movement attract attention) some birds will be attracted to it and the smell will still attract mammals. Visible bait will therefore be less selective than hidden bait.

To expect to develop a single bait for each of the three target animals is unrealistic. Animals learn and become uncatchable by any method that poses a threat to them. To make this concept work, continuous work on lures will have to be done. The weight of dog that cause damage range from ±5kg - ±50kg – no single bait could cover this range.

The statement is made that there is no difference between management of insect pests and problem animals. All the important aspects that have to be taken into account during control like population dynamics, behavior, learning ability, selectivity, reproductive strategy, numbers, distribution, seasonality, and application methods, to name a few differ totally in the two problems and the two has to be solved differently.

The impression is that the members of the Poison Working group have no experience in the finer application of damage control on ground level. Lack of knowledge in behavoir and learning ability is also apparent. The impression that all other control methods are unselective while the 1080 concept would be highly slecetive and effective is erronious. The problems come mainly from people applying the methods rather than from the equipment.

PRECEDENT IN OTHER COUNTRIES

1080 is used only by professional control operators for rodent control and only by government agencies for coyote control in the USA (Allen 1973, Atzert 1971, Boddicker 1993). Similarly 1080 is only used by governmental organizations in Australia and New Zeeland. 1080 has been used by the ton in the United States of America prior to 1972. The results were such that all poison use was banned during 1972 (Cain 1972). Since 1989 the EPA (Environmental Protection Agency) of the USA allows 1080 to be used only in the poison collar (Palmeteer 1990).

SUMMERY

1.       Single lethal dose poison baits have been used for over a hundred years in South Africa and haven’t solved any problem. P2

2.       The ideal ADC strategy is to kill only damage causing individual jackal. P2

3.       Farmers should not pay per predator, but for decreased in damage. P2

4.       Jackal has an unappreciated ability to learn and avoid control methods. P2,3,4

5.       Poison bait selects carrion feeding individuals instead of predatory individuals and this aggrevates the problem progressively. P4

6.       1080 is soluble and stable enough in water for practical use. P4

7.       The Poison Working Group is complicating a practical control method and making it so expensive that it becomes unusable and would not stop the abuse of other substances. P4

8.       The extrapolation of LD figures from related  groups is not valid. P5

9.       Stress and temperature play a big role in LD for 1080 and in the cold many non-target animals would die that would not at room temperature (where LDs are tested). P5,6

10.   The lethal dose of 1080 for jackal is higher than for overseas mammalian predators and lower for many of our raptors than for overseas vultures. Many raptors will die from a single jackal bait, but more so with a caracal bait from the 1080 SLD concept. P6,7

11.   Clinical dosing under field conditions is impossible. P6,7

12.   The time till death from 1080 poisoning is up to 36 hours in dogs. P6

13.   Promises of high selectivity and problem solving potential will never be realized. P6,7

14.   Vomiting by poisoned animals causes a non-target threat. P7

15.   Edible lures are not selective – other lures can be selective but is not eaten. P7,8

16.   Jackal has a high capacity to overcome serious control on its numbers, to the extent that eradication of jackal is practically impossible. P9

17.   As many control methods as possible must be used. P10

18.   Control methods cannot be dropped because it is sometimes abused and definitely not because some authors are not schooled in their proper use. P11

19.   The poison collar and about a dozen other control methods is more valuable as poison baits can ever be. P9,12

20.   Livestock owners need training in existing control methods much more than “new” poisons. Training must be professionalized and standardized. P9,12

21.   No current problem animal control specialist supports the Poison Working Group’s 1080 concept. P12

22.   1080 has been used by the ton since 1940 in the United States of America for coyote, with vast amounts of research on lures. In Australia for feral pigs, rabbits, foxes and dingoes. None of these problems was solved. P12

23.   In countries like the USA and Australia 1080 is used only by government agencies and by professional operators for rodents. 1080 has never been registered for use by private citizens (Allen 1973, Atzert 1971 & Boddicker 1993). P12

SUPPLEMENT TO M.J. DE WET 2002 POSITION: 1080 IN PROBLEM ANIMAL CONTROL 05/03/04

During December 2003 contact was made with researchers in New Zealand, Australia and the USA. Through this a number of publications on the practical application of 1080 in the above countries was acquired. This include information on the chemical stability in the environment that is of great importance in evaluating the poison for use in our environment.

McIlroy (1994) The chances that an animal will be poisoned by 1080 depends on many factors, of which the animals sensitivity is a key factor. This, however varies within the species with age and reproductive status. Also whether the animals ancestors came from an area with 1080 containing plants. Differences may also be due to the procedure with which the lethal dose (LD) was determined, and this does not always correspond with results under field conditions. The size of the animal is important as a small animal might have a high tolerance for 1080, but can consume only a small piece of bait to die.

There is an international increase in animal welfare issues in the animal management field, especially in the problem animal field where animals suffer during control work (Eason et al 1998). Continuous evaluation on the Humaneness, selectivity and other ethical aspects of each method should be done. It will be unwise to ignore this aspect and it will be plain stupid not to check this thoroughly before a new method is accepted. Once an organization has earned a bad reputation it will be extremely difficult to rectify the situation an the organization will end up as a target for extremist animal rights groups Eason et al 2000). Currently 6 poisons are used in New Zealand and this is re-evaluated for humanness, antidotes, effectiveness, selectiveness etc. (Eason 1995, Eason et al 1996, Eason et al 1997, Eisler 1995). Optimizing bait size and concentration of poisons to minimize environmental impact and non-target problems are solved (Frampton et al 1999). Public attitudes and views are also determined (Fraser 2001). Marks et al (2000) worked on additives to 1080 to get the death quicker and more humane (unsuccessfully). Investigation on the public view of poisons and their use in control is also done (Fraser 2001). Williams (1996) and Williams (1994) also investigated humaneness and acceptance of control by the public with emphasis on poisons. Continueing monitoring an adaption of methods by Thomas (1994, 1988), Tietjen et al (1988) en Titmarsh & O’Day (1983).

A child of 8 years was saved from death but retained serious neurological retardedness (McTaggart 1970). Suacide attempt by 15 year old girl – life saved but brain atrophy (Trabes et al 1983). Parkin et al (1977) cronic poisoning in rabbiter that handeled 1080 bait regularly in Australia. Human: 1080 not broken down by cooking meat (Milne et al 2001, Milne et al 2002).

TIME POISONOUS

Meeken & Booth (1997) carcasses of (Trichosurus vulpecula) remain poisonous enough to kill dog up to 75 days after a poison campaign. They warn that as long as any rotten meat is still present, dogs must be prevented from eating the carcass.

Twigg et al (2000) found that most meat baits remain poisonous for at least 8 months, even if it is rained upon. Dried meat baits remained poisonous for more than 12 months. Eggs into which poison was injected remained deadly to foxes for at least 63 days (Twigg et al 2001). Burns & Connolly (1995) Tested the contents of toxic collars on hay to determine the potential risk to sheep when collars leak. The toxin diminished but was not eliminated in the 12 weeks in which the study was done. They found that it needed at least 1 inch (25mm) of rain to eliminate the 1080.

RESISTANCE AGAINST 1080

King et al (1978) already described the adaptation of mammals the co-exist with 1080 containing plants, and later on that insectivores and predators developed tolerance against 1080 (King et al 1989)

Twigg et al (1991) discusses the issue of predators developing resistance to 1080 in areas where it occurs in plants. The mechanism works through insects and other herbivore consuming the plants and acquiring enough to induce resistance in their predators. This clearly illustrates how stable 1080, or its metabolites (which can also be poisonous) actually is in the food chain.

Resistance to 1080 poisoning has been documented, not only where 1080 containing plants occur, but also because of continuous poisoning campaigns like for rabbits in Australia (Twigg et al 2002). Hickling (1994) Also demonstrated behavioral and learned resistance. (Hickling et al 1999) Captive rats, with non-intensive selective breeding had a change in LD from 2mg/kg to 3.5mg/kg in the F4 generation.

Mead et al (1979) demonstrated a 150 times variation in resistance in Western Australian possums compared to the same species in Southern Australia (where the 1080plants occur and does not occur).

Innes & Baker (1999) Stress that long term ecological implications of chemicals in the environment is not easily predictable and should be monitored continuously. They recommend frequent meetings where managers (of poison use), policy makers, land owners scientists of a wide range of disciplines get  together to monitor environmental damage.

BAIT SHYNESS & PREBAITING

(Devine & Cook 1998) found an decrease in intake of all baits containing 1080 as compared to the same bait without 1080. Animals included rabbits, mice, rats and a number of indigenous Australian animals (Calver et al 1989). Devine & Cook (1998) discuss bait shyness and its prevention with 1080 in rabbits in New Zealand. Douglas(1979) experimented with 1080 bait for thar and stresses the value of prebaiting without which success is quite low. Kononen et al (1991) found mallards and bobwhite choose unpoisoned bait whenever they were presented with the same baits and only some would be poisoned. Livingstone (1994) warns about non-target kills and that target animals mostly developing resistance which leads to higher dosage and larger environmental danger.

Innes et al (1995) In 9 different field tests 87%-100% of rats was killed but it took only 4-5 months for the numbers to return to before the control.

O’Conner & Mathews (1999) possums caught in areas where no poisoning campaigns have been done showed no resistance to 1080, whereas possums from controlled areas showed a 60%-80% resistance to baits.

Natural suspicion against foreign bait (neophobia): Morgan (1990) poisoned carrots (1080) avoided by 27,5% of possums, by smell and taste. Morgan et al 1996 tested possums in captivity with sub-lethal dose and induced resistance to the bait. After 3 months they still had the resistance. Moss et al (1998) tested the effects of 1080 baits with: 1) no prebaiting, 2) prebaiting with RS5 bait, 3) prebaiting with green died, cinnamon flavored RS5. After two sublethal doses of 1080, 96% of 1), 55% of two and 9% of 3) resisted the bait. Ogilvie et al (1996), Ogilvie et al (2000) tested cut carrots with cereal. Prebait and then poison the cereal with 1080 (0,04% - sublethal). During prebaiting cereal was 64% of the diet and afterwards only 4%. Color and flavor in the cereal made no difference in consumption. Second study 60% cereal and after sublethal baiting only 2-4%.

Nachman & Hartley (1975) Experiment- rats drink sucrose. After 10 minutes intraperitonial sub-lethal poison injection. The stronger the reaction the greater the resistance. Rats refuse to drink sucrose again.

Ross et al (2000) Found 22% of prebaited possums developed resistance to bait while 97% of non-prebaited developed resistance. Free access to the same bait afterwards had made no difference to the number that did not feed. Only totally new bait were fed on.

Rowley (1963) noticed resistance by rabbits to bait under field poisoning within the first 10 years of using 1080 in Australia.

Alekseev & Turov (1967) Alekseev et al (1971) found that 1080 at sublethal doses killed fleas and investigated it as a systemic poison for external parasites. David & Gardiner (1958) also discusses 1080 as a systemic insecticide.

Dingo activity monitored after 1080 campiagn. Non-refined baits showed a decrease in dingoes at watrepoints, but highly refined baits showed no significant effect on dingoes (Eldridge et al 2000).

Secondary poisoning was found by many overseas authors. Many trails were done with radio collard predators were present in areas where poisoning was done. Mostly all the radio marked animals were killed. The results of these studies are summarized in the table. Secondary poisoning is seen as a killing two birds with one stone. The exotic possums and rodents are the original target, but as a bonus cats, stoats and ferrets are also killed when they scavenge of the carcasses. Hegdal et al (1986) “...Laboratory studies have repeatedly shown that 1080 theoretically poses hazards to non-target wildlife through both primary poisoning and secondary poisoning...”  

DOCUMENTED SECONDARY POISONING WITH 1080

Koenig & Reynolds (1987) indicate that certain birds will be poisoned by baits placed for rodents and that the birds then die on their nests and the carcasses not found. Marsh et al (1987) coyotes died of heigher dosages for prairie dogs, but not of the lower dosages. Notman (1989) found insectivores are killed when they feed on insects feed as non-target animals, on baits that are laid for possums and rodents. Further references to invertebrates and the socondary danger to inectivores from Spurr (1991), Spurr & Drew (1999), Spurr & Berben (2002),Tahori (1966) & Twigg (1990).

One of the symptoms of 1080 poisoning is severe vomiting and this is seen in most animals. The vomitis contain 1080 to the extent that is a threat to non-target animals. Some drugs to try and prevent the vomiting has been tried but without success (O’Brien et al 1986,  Cai et al 1997, Chi et al 1996, Eason et al 1994, Fry et al 1986, Gammie 1980, Green 1992, McIlroy 1983, McIlroy & Gifford 1992, Morgan 1990, O’Brien 1988, O,Brien et al 1988 & Rathmore 1985).

In the experiment by Schitoskey (1993) kit foxes died from kangaroo rats poisoned with 0.74mg 1080 while surviving rats poisoned with 3 times the LD for foxes – much more than the fox would have eaten on its own.

Powlsland et al (1998, 1999, 2000)  -  1080 control of possums. Rather rats reduced by 90% and robins by 54,5%. While 24 marked robins in control area all survive. All  five tomtits died plus 1 of 6 morepork. 79% of  tomtits dead,  Pureora 43% of  robins died with 1080 poison campaign.

Short et al (1997) used rat carcasses with 4.5mg 1080 to kill house cats in a nature reserve in Australia. All radio collard cats were killed and there was a 74% drop in cats during spotlight censusing.

Other symptoms: Ataria J.M. et al (2000) found extensive muscle necrosis in birds with 1080 poisoning and speculates that this might be the unique target organ in birds. This implies that even if birds do not die or show severe symptoms they might still be compromised to the extent that they may not survive in the long run. Cottral et al (1947) found enteritis, bleeding and fluid in the lungs of chicken. Fry et al (1986) found a high resistance in condors but warns that the effect of damage to the nervous system is unknown. Schwarte (1947) found that repeated sublethal dosing showed cumulative effects in chicken. Shlosberg & Egyed (1975) found the death of four kinds of geese and chukkar partridges could be attributed to 1080 corn bait for rats.

Barnett & Spencer (1949) already noted that some birds are killed with 1080 rodent baits, and feel that it is to dangerous for general use because of inconsistant results, especially after prebaiting.

Mazzanti L. (1965) found atrofication in rat testes after 1080 poisoning.  More evidence of damage to reproductive system in male animals from Steinberger & Sud (1970), Sullivan et al (1978), Sullivan et al (1979) & Twigg et al (1988).

Schwarte (1947) found that repeated sublethal dosing showed cumalative effects in chicken.

Dingo activities monitored after 1080 application: non-refined baits caused a decline in dingoes, but refined baits could not achieve the same. Fleming et al (1996) after even large scale control on dogs, numbers returned to pre-poisoning level within one year.

Variation in LD between groups, application and with temperature

Chenoweth (1949) reported large differences between species with 1080 poisoning and ascribe this to differences in the metabolism of the animals. Anonymous (1979) found LD₅₀ values significantly higher than pervious studies and ascribed this to factors like age, sex, physical condition, weather, stress, season, time of day and application of the poison.

Burns & Connolly (1992) demonstrated differences with temperature in magpies in the USA, but greater variation was found by Oliver & King (1983). They found LD50 at 12,2°C to be five times lower than at 24°C. Their findings indicate that extremes in temperature causes the animals to be much more vulnerable to 1080 poisoning. Fry et al (1989) indicated the same effect on condors while Hornshaw et al (1986) indicated the same for turkey vultures. They feel that the debilitating effects of sublethal 1080 poisoning would probably lead to the birds death under free living conditions and indicated differences between adult, young and pregnant animals. Misustova et al (1969) mice – 5mg/kg dosage killed 3% of mice at 23^oC but 47% at 17^oC. LD50 dropped from 21.1mg/kg (23^oC) to 5.16mg/kg (17^oC). Hudson et al (1972) different LDs for different ages in the same duck species.

This has huge implications for non-target deaths where poison is applied in colder parts of the country duringwintertime at night. It also makes terms like  “maximum dosage” and “clinical dosage” nonsensical with application under field conditions. The dosage for turkey vultures found to be temperature dependant and that debilitating symptoms of sub-lethal dosages would probably lead to the birds death under free roaming conditions. Evidence of the effects of temperature under natural conditions summerised by Veltman & Pinder (2001) as for control of possums with 1080.

Differences in 1080 LDs between young, older nd pregnant animals indicated by  (Hornshaw et al 1986). Hudson et al (1972) differences in LDs for ducks of same kind but different ages 

Martin & Twigg (2001) documented differences in sensitivity for the same species in populations comming from areas where plants containing 1080 occur as compared to the same species where those plants do not occur.

Martin et al (2002) states that laboratory tests should guide field tests, but it has to be interpreted carefully and that extrapolations usually are not valid.

O’Brien et al (1988) Found the same dosage of 1080 in corn bait to kill a considerable higher percentage of pigs than the same 1080 in pellet bait. The average LD₅₀ in corn was 4.11 mg/kg. The variation, however was 3.02-5.34mg/kg O’Brien (1988). The same author also indicate the LD₉₀ as 11,25mg/kg with variation between 8.05-21.69mg/kg. These large variations is a clear problem with 1080 that limits the application. O’Brien & Lukins (1988) showed that type of bait, sex, size of the pig, and locality influenced the intake of 1080 bait significantly. O’Conner et al (1999) found pregnant ewes to be much more sesitive than other sheep, even to small fragments of bait and O’Conner & Mathews (1999) showed that possums with no experience of poison baiting had no resisstance to baits, but that possums from areas where bait had previously been appled had a 60-80% of the population resisstance to taking the bait.

Steyn (1934) discusses the phenomonon of resistance to intake of poisonous plants like Dichpetalum. Oliver et al (1979) uses differnces in genetic resisstance to 1080 in relation to the distribution of 1080 containing plants to work out the original distriburion of herbivores. Twigg (1994) describes the relation between 1080 containing plants and the resisstance to 1080 in Australian animals.

LD₅₀ for cats found to be 0.28mg/kg with variation of 0.07-0.49 and LD₉₀ of 0.35mg/kg (0.14-0.56) (Eason & Frampton 1991). For successful control and little resistance to the method, the maximum dosage should be used (0.56). O’Brien (1988) found the average LD₅₀ in corn for pig to be 4.11 mg/kg. The variation was 3.02-5.34mg/kg. The LD₉₀ was 11,25mg/kg and variation 8.05-21.69mg/kg. O’Brien et al (1988) found 1080 in corn bait killed a significantly higher percentage of pigs than the same dosage in pellets. O’Brien & Lukins (1988) indicated that the kind of bait, sex and size of pigs and the locality al played a significant role in the intake of 1080 by pigs.

O’Conner et al (1999)- pregnant ewes are more sensitive to 1080 than other sheep, even small fragments of bait.

Oliver et al (1979) used differences in genetic resistance to 1080 of indigenous Australian animals in relation to 1080 containing plants, to work out geographical origins of those species.  

California quail – LD between 1-5mg/kg (Sayama & Brunetti 1952). For such a small bird any larger mammalian target animals’ bait would contain lathal amounts of 1080. Quial is closely related to our francolin. Here is another warning not to use the poison in our system.

The large variations found in 1080 dosages and variations due to temperature etc. clearly has huge implications in its application. It negates claims of applying it to baits in “maximum” and “clinical” dosages.

  CHANGES IN LD₅₀ FOR 1080 WITH TEMPERATURE IN MICE (Oliver & King 1983)

Same trend found for marmots and possums as well.

 CHANGES IN LD₅₀ FOR 1080 WITH TEMPERATURE IN MICE (Misustova et al 1969)

DIFFERENCES BETWEEN LD₅₀ EN LD₉₀ FOR 1080, IN PIGS AND CATS

Alternatives. Eason et al (1998), Eason C.T. (1991) examples of the search for alternative toxins and/or control methods for animal damage. (Eason 1992, Fedwick et al 1998, Mead et al 1991, Menon et al 2001 ) all mention Gliftor – the active principle is 1,3-difluoro-2-propanol. Some of the symptoms is similar to 1080, but there is an antidote, 4-methylpyrazole.

When a poison is evaluated to be released in an environment two baselines need to be established. The  “no observed adverse effects level” (NOAEL) and the “lowest observed effects level” (LOAEL). To do this, a whole range of possible non-traget animal lethal dosages need to be known, including invertebrates, herbivores, predators, birds, and reptiles.  

When poisons are evaluated to be released in the environment two baselines must be established: “no observed adverse effects level” (NOAEL) and “lowest observed effects level” (LOAEL). To do this LD values for all the animals and other organisms that might be effected is essential. Included is insects, insectivores, herbivores, predators, birds, reptiles etc.

Fleming et al (1996) records the quick recovery even after large scale control of wild feral dogs in Australia – numbers are back to before control level within a year after the operation.  

Time frames for 1080. Burns et al (1996) coyotes showed symptoms by 3hours and 23 minutes after poisoning and died after 5 hours. Eason et al 1994 rabbit died after 1hour, mouse 2 hours, goat 56 hours & sheep 11 hours. McIlroy (1986) states that 1080 shows lots of variation and that LDs cannot be predicted from related species. Of the 171 species that he has data the variation in time to produce symptoms was between 0.1 hour and 7 days. Time till death was 0.1 hour to 21 days. O’Conner et al (2000) found it took about 11.5 hours application of 1080 for a possum to die with an 8 hour period of vomiting and other symptoms.

From this information it is clear that 1080 is an undesirable poison to be released in our environment, and it is recommended that this project is not supported.