Oral Contraceptives - Ornitrol & Ovocontrol P

OvoControl P Pellets

OvoControl P Pellets

Oral birth control is not commonly used for the control of birds and previous attempts to find an effective and humane oral contraceptive for the control of feral pigeons have been unsuccessful. Research is ongoing, however, to produce an oral contraceptive drug that can be fed to pigeons and other problem birds in an effort to reduce flock size humanely and in a cost-effective manner. Other methods of birth control that are commonly used to control pigeon flock size include the removal and replacement of eggs (from artificial breeding facilities) and, to a lesser extent, ‘egg oiling’. Egg oiling is an extremely effective method of bird control which involves immersing newly-laid eggs in paraffin BP to block the pores of the egg, denying oxygen to the undeveloped foetus. Egg oiling and egg removal/replacement are both tried and tested methods of birth control that are considered to be highly effective in the control of pigeons and other birds alike. The use of ‘egg oiling’ as a method of control is discussed, in detail, in a dedicated product/service review entitled ‘Egg oiling’. Schemes involving egg removal/egg replacement from artificial breeding facilities are discussed in the 'Artificial breeding facilities' product review.

At present there are no oral contraceptives available in the UK that are licensed for use with pigeons or any other birds. The Department of the Environment, Food and Rural Affairs (DEFRA) has confirmed that although it has commissioned research into contraceptives for animals, it has not been in a position to commission research into contraceptives designed to be used for birds. This is because all species of birds are protected in the UK whereas the same cannot be said of animals and their lack of legal protection allows trials of this nature to be carried out.

Oral contraceptives for birds are far from common and those that have made it into the commercial marketplace have not been popular nor sold well. The best known avian oral contraceptive is a drug called Ornitrol that was developed for use as a bird and animal contraceptive on the back of its development as a cholesterol inhibitor in humans. The active ingredient diazacon (20,25 diazacholesterol) is a cholesterol mimic that inhibits cholesterol production and blocks steroid hormone formation. The reason that the drug was first considered for bird control was based on the fact that as eggs contain cholesterol, diazacon may lower cholesterol at the same time as inhibiting reproduction. More importantly, diazacholesterol 20,25 may have the ability to block the production of hormones (estrogen, testosterone and progesterone), all necessary for reproduction. Tests were carried out using sparrows and pigeons and it was found that diazacholesterol 20,25 was effective in reducing reproduction in both species. As a result the product was registered as a means of controlling pigeon populations under the trade name of Ornitrol.

Ornitrol was designed to be used in the same way that narcotic baits such as Avitrol are used to kill pigeons, by feeding non-treated grain on the chosen site for 7-10 days and then substituting the treated grain for grain treated with Ornitrol. This treatment was sufficient to make female pigeons sterile for up to 6 months. The process is then repeated every 6 months indefinitely. Ornitrol administered to pigeons acts in the same way as a human birth control pill, if the drug is not consumed every 6 months female pigeons become fertile once more and continue to breed unhampered.

Ornitrol is now no longer produced but its development as a reproductive control has led to the current research and development of drugs such as OvoControl G and P, relatively new birth control drugs designed for use with Canada geese and feral pigeons respectively. Ornitrol was discontinued due to concerns about the long-term use of the drug and the fact that in the form it was produced it was easily and quickly consumed by non-target species. For use on birds like pigeons that breed all year round, Ornitrol would need to be used continually throughout the year and it was found that the drug caused muscle tremors in pigeons when used over long periods. Not only this, but the drug was also extremely expensive to provide on this basis.

OvoControl P is a drug produced by an American company called Innolytics that is designed to control the “hatchability of eggs”, according to the manufacturer. The active ingredient of the contraceptive is nicarbazin, a drug originally used to control enteric disease in chickens. OvoControl works by interfering with the vitelline layer of the egg, separating the egg white from the yolk. The vitelline layer is a membrane that is vital for the development of an egg and without it the egg will not hatch.

Unlike Ornitrol, OvoControl P is fed to pigeons from day 1 but during the acclimatisation process (normally lasting between 5 and 14 days) OvoControl P is fed at a reduced level of 1 ounce (28 grammes) per 30 birds. As pigeons become acclimatised to feeding on the site OvoControl P can then be increased up to a maximum of 1 ounce (28 grammes) per 5 birds. The main criteria for the use of OvoControl P is a site where pigeons can be encouraged to feed on a daily basis, ideally at the same time each day and where there are no non-target species present. The manufacturer suggests that OvoControl P should be fed in the early hours of the morning and ideally on flat rooftops or, if rooftops are not available, on flat paved areas that are consistent with the restrictions imposed on the use and distribution of the drug. Wherever possible OvoControl P should be fed to pigeons close to their roosts or daytime perching places.

The following chart outlines dosage per pigeon with the basic calculation being: estimated pigeon population x 0.2 ounces (5.5 grams) of OvoControl P = amount of OvoControl P to be fed daily.

  • 2 ounces (56 grammes) of bait = 10 pigeons
  • 8 ounces (224 grammes) of bait = 40 pigeons
  • 1 pound (0.4 kilogramme) of bait = 80 pigeons
  • 5 pounds (2.2 kilogrammes) of bait = 400 pigeons
  • 10 pounds (4.4 kilogrammes) of bait = 800 pigeons
  • 30 pounds (13.6 kilogrammes) of bait = 2,400 pigeons
  • 2 cups of bait = 14 ounces (0.3 kilogrammes) = 70 pigeons
  • 1 gal of bait = 112 ounces (3.1 kilogrammes) = 560 pigeons

Mechanical Distributor for OvoControl P

Mechanical Distributor
for OvoControl P

The manufacturer suggests that OvoControl P can be fed to pigeons using a variety of methods. Options include the use of various sized and shaped containers containing the drug in order to accommodate all pigeons feeding on the site, including dominant cock birds and submissive/juvenile birds. Containers must be perforated to allow drainage. This method is only recommended on sites where the flock consists of less than 50 birds. Other methods include hand feeding (broadcast distribution) where the drug is distributed over an area not more than 20 feet radius (6 metre radius) and mechanical feeding, a method used for pigeon flocks of more than 50 birds. The broadcast limit for mechanical feeders must be set to a radius of no more than 20 feet (6 metres). Mechanical feeders should only be used on flat roof areas or flat paved areas that have restricted public access.

The recommended use of mechanical feeders suggests that OvoControl P can be used without the need for a human presence but this is not the case. Clearly a human presence is required to identify non-target species birds, to assess flock size prior to distributing OvoControl P, to remove OvoControl P in wet conditions and to ensure that children and pets do not come into contact with the drug. The suggested use of mechanical feeders, outlined on the OvoControl P website, is misleading and may result in some users simply ignoring the operational requirements of OvoControl P and distributing the drug indiscriminately.

There are a number of restrictions involved with the use of OvoControl P which include:

  • OvoControl P must be used throughout the entire breeding period – in pigeons this is 365 days a year and OvoControl must be distributed every day
  • The human applicator must visit the site early in the morning to distribute OvoControl P
  • The human applicator must thoroughly assess pigeon activity on the site prior to distributing OvoControl P and undertake a pigeon head count each day
  • The human applicator must reduce/increase the volume of OvoControl P fed each day according to the results of the head count to ensure optimum coverage for the whole flock
  • The human applicator must ensure that children and pets do not come into contact with OvoControl P
  • The human applicator must remain on site for up to one hour to ensure that all the bait is eaten and to ensure that non-target species do not attempt to exploit the bait
  • The human applicator must ensure that no non-target species are feeding on site during the distribution process and whilst the bait is being consumed by pigeons or the applicator may be committing an offence. In the USA it is an offence to feed treated bait to protected, threatened and endangered birds
  • Daily observations for non-target species birds must be carried out throughout the 5-14 day acclimatisation period and once a week thereafter
  • OvoControl P must not be used in rain and neither should the drug be used within 20 feet of any body of water including ponds, rivers and lakes – when distributed on rooftops or paved areas in wet conditions the area in which OvoControl P is to be distributed must be dry and ideally beneath some type of canopy
  • OvoControl P can only be used in urban applications and on flat roof areas or paved areas where public access is restricted
  • Health and safety must be assessed and health and safety restrictions include: wearing protective eyewear (as OvoControl causes moderate eye irritation), washing all contaminated clothing before re-use, washing thoroughly after handling OvoControl P and before eating, drinking or smoking. Gloves, long-sleeved shirt and long trousers must be worn at all times when handling or distributing OvoControl P

The manufacturer confirms that OvoControl P will render all birds that take the bait sterile, including protected species, but claims that OvoControl P is manufactured and provided in a format that will only be palatable to pigeons. The manufacturer provides a very long list of restrictions for use, however, suggesting that exploitation by non-target species is a real concern and yet no formal training is required for human applicators. The most significant concerns raised in respect of all orally fed contraceptive drugs are their impact on non-target species. Although the manufacturer suggests that that there is little likelihood of exploitation by non-target species, as a result of the size and shape of the bait, there is still an admission that the drug can be ingested by protected birds. The manufacturer suggests that a bird the size of a songbird or sparrow would not be interested in OvoControl P, but there is no advice or comment made in respect of larger birds exploiting the bait. The only mechanism available to stop non-target species exploiting the bait is the human applicator and the ability of that person to identify non-target species and to scare them from the site. Identification and the scaring of non-target species is also dependent on the human applicator remaining on-site, in all weather conditions, for the requisite 1 hour period following distribution. The only positive aspect of OvoControl P over drugs like Ornitrol is the fact that secondary toxicity cannot take place. According to the manufacturer, non-target effects can only result from direct ingestion of OvoControl P.

Health and safety guidance provided by the manufacturer also suggests that OvoControl P can cause “moderate eye irritation” to the human applicator. If the human applicator is required to wear protective eyewear as a result of concerns over safety, what affect will OvoControl have on the target species? It must be assumed that if OvoControl can cause moderate irritation to the human eye the same must apply to the avian eye, bringing health and safety of the target species into question. No mention is made of this fairly obvious welfare concern on the Innolytics website . Animal protection laws in the USA are far less comprehensive than equivalent legislation in the UK and the criteria required to attract a licence for a new drug in the USA may be less challenging than criteria necessary for a similar application in the UK. If OvoControl P can cause irritation in the avian eye there is clearly the potential, in extreme cases, for sight to be compromised with potentially lethal consequences.

The most obvious problem associated with the use of OvoControl P to control pigeon populations is the cost of the control, not only in terms of the cost of the drug itself but, more importantly, the cost in human time. For an individual to be expected to attend a rooftop site every day, 365 days a year and in all weathers, to spend upwards of an hour assessing pigeon activity, distributing bait and then watching for non-target species is a big ask for any property owner. The early hours of the morning are considered to be anti-social hours and therefore premium rates would have to be paid to employees undertaking the required tasks and protective clothing would also need to be provided. Not only this, but contaminated clothing must be washed prior to re-use and showering facilities may need to be provided on site. There is a great deal of responsibility placed on the individual/s carrying out the daily distribution and assessment works, not only to carry out a pigeon head count but also to ensure that non-target species do not exploit the bait and that no children and pets access the distribution area. If rain starts to fall it must be assumed that the human applicator must also be available to sweep up all the OvoControl P pellets before they become contaminated with water.

Any option to control pigeon flock size humanely and effectively must be viewed as a positive development and although trials suggest that OvoControl P can be effective in reducing pigeon flock size, the cost of the control and the question of welfare is inevitably brought into question. Following in the footsteps of Ornitrol, a poorly performing and extremely expensive contraceptive drug, it was incumbent on the manufacturer of OvoControl P to provide an option that outperformed Ornitrol in every department. To an extent Innolytics has achieved this by providing a drug that has few known side effects and which, they claim, is unlikely to be exploited by non-target species. If the drug is as effective as the manufacturer claims and assuming that the drug is unlikely to be exploited by non-target species, will the sheer cost of human interaction render it too expensive to use? Based on the information supplied by the manufacturer the answer to that question has to be a resounding “yes”. Pest control budgets are notoriously low with most property owners budgeting only a few hundred pounds for all their pest control needs (including budgets for rodent control) so it seems highly unlikely that any company or individual will be prepared to put aside what must be considered to be a huge annual sum in order to use OvoControl P.

Although OvoControl P appears to have clear advantages as a means of reducing the breeding potential of the feral pigeon, the product offers little in the way of relief for the property owner experiencing entrenched pigeon-related problems. The manufacturer confirms that OvoControl P should be used as part of an overall control system rather than as a stand-alone control, but this begs the question - why would a property owner choose to use OvoControl P as well as conventional control options? The cost of using OvoControl P for one year would almost certainly allow most property owners to comprehensively protect their entire property with an industry standard anti-perching product. Once a property is protected with a product like the anti-roosting spike, the property owner would have anything from 10-30 years of relief without the need to spend more money. If the same property owner used OvoControl and anti-perching products to protect their property the cost would not only be extreme in the first year (with the cost of spikes and OvoControl P) but the property owner would have to continue spending large sums every year for the continued use of OvoControl P.

For a city council or a government body that has responsibility for area-wide pigeon control, the use of OvoControl P may be considered as an option in an effort to reduce the size of urban pigeon flocks. For the individual or the commercial property owner, however, the product must be considered to be prohibitively expensive to use, offering far less value than conventional anti-perching and exclusion products. It is possible that council or government bodies could undertake area-wide trials, offering grants to property owners to trial the use of OvoControl P on their sites or properties, but it is hard to see any application for the product for the average property or site.

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DEFRA’s view:

As there are no avian oral contraceptive drugs available in the UK at present, DEFRA does not discuss this control option on its website. A spokesperson for DEFRA did confirm, however, that should a product like OvoControl P be made available in the UK, all the science involved with the drug as well as details of the preferred delivery mechanisms would be required in order to make a decision as to whether that drug was suitable to be licenced for use in the UK.

The Health and safety Executive (HSE) confirmed that any employer using a birth control product on their site must carry out an in-depth risk assessment confirming that the product is safe to use and also confirming that the use of the product on-site conforms to Section 2 of the Health and Safety at Work Act. The HSE also confirmed that the manufacturer of the product has a duty to divulge any and all information about the product via a detailed data sheet. Any drug used to induce sterility in a bird would be listed as a product that is potentially hazardous to human health and as such would be listed as such under the Control of Substances Hazardous to Health Act.

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Price range:

The cost of OvoControl P is $4.88 per lb. In real terms this equates to approximately $6 a day to treat 100 pigeons Mechanical feeders are available for automatic distribution of OvoControl P:

  • Durable Baked on Green Scatter Feeder $500.00
  • 22 gauge Galvanised Finish Feeder $450.00
  • Optional Green or Galvanised Solar Panel $75.00

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User reviews:

To date we have been unable to find any user reviews for oral contraceptives but we will update this section as and when user reviews are made available to us. If you are able to provide a user review for oral contraceptives please contact the Pigeon Control Resource Centre.

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Comments from the Manufacturer/Distributor:

The following is taken from the Innolytics website:

“Innolytics, LLC has developed an innovative and humane technology to help control the population growth of pest avian species. The technology, developed in collaboration with the USDA/APHIS National Wildlife Research Center (NWRC), essentially represents oral contraception for birds. There is no comparable technology on the market in the USA today. The product is called OvoControl.

Originally developed to help manage the burgeoning resident Canada goose population in the Northwest, Mideast and Northeastern areas of the United States, the US Environmental Protection Agency (“EPA”) recently registered the product for use in pigeons.

Pigeons, the ubiquitous bird that populates virtually all cities, towns and industrial sites are typically managed with exclusion techniques, poisoning or trapping. While the exclusion devices will keep birds away from a specific building or location, the underlying bird population continues to grow. The use of OvoControl complements exclusion techniques – nets, spikes and electrified strips – and provides an alternative to poisoning or trapping birds.

OvoControl for pigeons is ideal for use at large scale sites and facilities, areas where some birds can be tolerated, but where a significant reduction in the population is desired. Potential sites include urban areas, schools, airports, power plants and refineries. Large scale field studies at urban sites in Italy demonstrate a population decline of nearly 50% in just two years.

The core technology for OvoControl centers on the proven ability to significantly decrease the hatchability of eggs by feeding treated bait to birds during the reproductive season. The effect is fully reversible and care has been taken to develop a feeding system which will limit exposure to non-target species. The USDA conducted extensive research on this technology and continues to evaluate further applications in other pest species.

The EPA granted the first registration for egg hatch control for resident Canada geese in 2005 and subsequently registered the product for pigeons in 2007. Ducks and other development projects are underway for a range of other bird species.

Innolytics’ OvoControl technology enjoys the full support of the leading animal welfare and conservation organizations in the US and abroad.”

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Editorial comments:

The use of oral contraceptives for bird control has been debated internationally for decades with early research in Europe drawing few conclusions about their effectiveness or whether chemosterilants should be used at all. Swiss trials found that it was impossible to isolate feral flocks in order to assess whether contraceptives could be used to reduce breeding. Because pigeons are highly mobile, using multiple feeding sites each day, the same birds could not be relied upon to visit test sites each and every day, particularly at the precise time that treated grain was being offered. Pigeons from specific feeding flocks were also found to integrate with other feeding flocks on an irregular basis, rendering any data collected corrupt. Laboratory experiments can be undertaken to assess the effectiveness of contraceptives, but laboratory environments do not, in any way, mimic the pigeon’s natural habitat.

The only oral contraceptive available that is designed specifically for use with pigeons is OvoControl P with its sister product OvoControl G, used for the control of Canada geese. Both products have been passed for use in the USA by the US Environmental Protection Agency (EPA), but standards adopted by EPA are unlikely to be considered acceptable in the UK and some other European countries. Trials undertaken by the manufacturer of OvoControl P in Italy have apparently provided some quite astonishing results with reductions of up to 50% in under two years, but no detailed information is available about these trials on the Innolytics website. As Innolytics suggest that OvoControl P should be used as part of a comprehensive control regime it is quite possible that culling was used as an additional control to compliment the use of OvoControl P. This may account for the unusually large reduction in flock size in such a relatively short period. It should also be noted that many US companies trial their products in Italy and although there is no obvious reason why this should be the case, it is possible that Italy has relaxed animal protection laws as does the USA.

Other methods of breeding control do achieve extraordinary results, such as the use of artificial breeding facilities where eggs are removed and replaced with dummy eggs on a weekly basis. This control, pioneered by the UK-based Pigeon Control Advisory Service (PiCAS International), is now used extensively across Europe and has been found to reduce flock size dramatically and within short time frames. The egg removal/replacement method of control is not labour intensive (5 minutes a week to remove and replace eggs), costs virtually nothing and stops all breeding talking place within the breeding facility. OvoControl P, relative to this control option, is extremely expensive, is not guaranteed to be effective and offers the property owner on whose building the problem exists, no relief whatsoever. Pigeons will quickly learn to use artificial breeding facilities, even if their existing roosts are left unprotected and once established within lofts the birds will breed openly, irrespective of whether their eggs are interfered with or not.

OvoControl P is a good idea but fatally flawed in terms of its operational costs and the need to continue to offer the control indefinitely. OvoControl must be provided every day, 365 days a year, no exceptions. Most property owners that experience problems with pigeons do not have pigeons roosting overnight and breeding on their property, they simply have daytime perching problems where pigeons are using their property for the purposes of exploiting a food source. For these property owners to use OvoControl P as well as installing anti-perching products does not make sense. OvoControl P is designed to reduce flock size by birth control, a long-term goal, whereas anti-perching products will provide any property owner with instant and comprehensive relief, assuming that the product has been installed as per manufacturers’ recommendations. For local authorities to use oral contraceptives in order to reduce flock size in an effort to provide property owners with some long-term relief (and spend less on purchasing deterrents) makes perfect sense and is a control option that would justify the use of public money to provide. To expect individuals and property owners to employ controls of this nature is simply pushing the envelope a little too far.

Although the manufacturer of OvoControl P suggests that there is little if no chance of non-target species taking the bait, there is no doubt that if this were the case the product would be recommended for much wider use. OvoControl P has been designed in such a way that it is difficult for smaller birds to exploit, but not impossible. There is also the issue of larger birds taking the bait. Whether or not non-target species are able or inclined to take the bait is critically important to the success of any type of contraceptive and until such a time as a product is designed that is species-specific and that cannot be exploited by non-target species, this control option will inevitably have its critics.

The issue of health and safety, not only for the human applicator of the product but also for the target species, is another issue that needs further research and investigation. A product that can cause “moderate irritation” to human eyes will almost certainly have the same effect on avian eyes. Although it must be borne in mind that the USA, where this product is approved for use, has far more relaxed animal protection laws than the UK, there is no doubt that this issue of potential suffering will be a cause for concern in the UK and many European countries. It is unlikely that OvoControl P will be introduced into the UK in the foreseeable future and if the product was introduced in its present format it is unlikely to be approved for use by DEFRA or the HSE.

Also commonly known as:

Ornitrol, OvoControl, OvoControl P, ovoControl G, the pigeon pill, pigeon contraceptive

Relevance to pigeon control:

Oral birth control is used as a method of pigeon control

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