|
|
|
BIRD BIOLOGY AND DISEASES |
|
|
|
|
|
|
|
DISEASES CAUSED BY BIRDS |
|
|
|
INTRODUCTION
Disease potential which exists when birds such as pigeons are permitted to roost in areas frequented by humans. For example, pigeons roosting and nesting on roofs, around air conditioning systems, in steeples etc.
Apart from the disease hazard, wet bird droppings are slippery and can lead to people slipping and falling onto solid surfaces such as sidewalks. Bird roosts are frequently infested with flies as well as several species of parasites such as bird mites, ticks etc., which bite humans, & can readily cause infection. Bird roosts are also smelly, the presence of accumulated bird droppings can block gutters and drains and the acidity in bird droppings causes permanent damage to metal surfaces, painted surfaces etc. Quite often the cost of repair and replacement of damaged surfaces exceeds the cost of exclusion.
The white material you see in droppings is uric acid which is a very powerful acid. It will eat through steel, the final finish on automotive paint etc. and cause permanent damage. In addition, there are yeasts which live in bird feces and as these yeasts live they also excrete acids. So wherever you have bird feces you have the on-going generation of powerful acids and their corrosive effects.
There are over 40 known virus and 60 diseases directly associated with birds and their droppings. These diseases vary in seriousness from minor stomach ailments to fatal diseases such as histoplasmosis, which is the one disease which is now most common.
Histoplasmosis is a fungus which is found in the soil, particularly soil with a high nitrogen content and it is enriched by the droppings of birds and bats. It thrives in warm temperatures and in moist conditions especially in areas such as bird roosts, caves infested with bats, school yards, chicken coops, areas where there is rotten or decaying wood etc. It is contracted when the soil from an infected area is disturbed and tiny spores are inhaled. These spores enter the lungs and can then be transported around the body.
Birds can carry histoplasmosis fungus on their legs, feet, wings etc. but they are not infected with histoplasmosis, most likely because of their high body temperature. However bats do carry and do excrete histoplasmosis. Apart from humans, animals such as dogs, cats, rats, skunks, foxes etc. also are susceptible to this disease.
It is estimated that in n America alone, 50 million people have been infected with this fungus, approximately 500,000 test positive each year and we have about 800 deaths.
It usually appears as mild, flu-like symptoms, chest pain, dry cough etc. A chest X-Ray will show a very distinctive pattern like “snowballs”.
Dust and dirt containing histoplasmosis spores can be carried over a long distance and hence can affect a number of workers on an infected site.
Once airborne, these spores can be carried for quite long distances by the wind. It was such an activity which caused the three largest known outbreaks of Histoplasmosis on record and all occurred in Indianapolis.
1978; 120,000 people infected and 15 died.
1980; similar to 1978
1988(50% of the cases were AIDS sufferers)
In 1978 the American Journal of epidemiology reported that workers were shoveling excessive bird droppings from the roof of a courthouse to the ground for removal. The dust from this procedure was picked up by the window air conditioners and re-distributed throughout the entire building. Over 50% of the occupants contracted Histoplasmosis and one person had only been in the building for 10 minutes.
Several cases of Cryptococcocal meningitis have been reported where workers exposed to bird droppings have developed a chronic inflammation of the brain tissue. A window cleaner in California lost 50% of his lung capacity because he came into regular contact with bird droppings on window ledges.
Water sprays and other dust suppression methods should be used when handling dirt/droppings in infected areas.
The only known product to kill these spores is a 3% solution of formaldehyde however workers in potentially infected areas should take necessary precautions. Wear a respirator with a hepa filter and certainly wet droppings down before clean up and removal.
There are two chemicals available through Hot Foot America which can significantly improve the on-site hygiene, odor control and clean up. The first, Steriliz-It (manufacturers name is ENACT) is an EPA registered sterilizing agent which will kill bacteria and virus on contact. However it will not kill spores. Sterliz-It should be used every time clean up of bird feces is required and the droppings should be wet all the way through (like wet coffee grounds) before any attempt is made to sweep and bag for disposal. Steriliz-It contains not only a powerful germicidal agent but also a 3% concentration of detergent and a true odor neutralizer. This will kill the smell of bird droppings as well as its sanitizing effect.
In cases where accumulated bird droppings have blocked gutters, downspouts etc., “Digest-It” should be used. This is a mixture of 3 enzymes which actually digest the fatty acids present in feces. This causes the feces to break down to aid in clearing accumulated excretions. It also contains an odor neutralizer like Steriliz-It.
 |
|
|
|
|
|
|
|
BIRD BIOLOGY
|
|
|
|
PIGEONS
The domestic or City pigeon (Columbia Livia) has evolved from the Rock Dove of Europe and Asia and was introduced into the USA as a domestic bird. Today, pigeons are the most widely dispersed of all animal species and in their early beginnings they nested in caves, holes and rocks in overhanging sections of cliff faces etc. today they are quite comfortable nesting in eaves, under air conditioners etc. which are quiet, dark areas protected from the sight of predators. They also nest openly on ledges, adjacent to dormers on residences etc.
Pigeons are typically monogamous, having only one partner for life, however if separated for any reason such as death then the remaining partner will re-mate within a matter of days. The nest site is usually chosen by the male who then typically brings the nesting material to the female. It is the female which then constructs the nest by thatching around her body. Flat, smooth surfaces near an abundant source of water are preferred for nesting and roosting.
The male bird is sexually mature at 3-4 months and the female at 6 months. 1-2 creamy-white eggs are laid 8-12 days after mating and these are incubated for approximately 18 days. Traditionally the male incubates the eggs in the morning and the female in late afternoon and evening. Babies fly at 5 weeks and the life span of a city pigeon ranges from 3-15 years depending on food sources, climate etc.
One pigeon pair usually raises 10 young birds annually. Although primarily grain and seed-eaters, pigeons are adapted to eating insects, garbage, spilled grains, food left out by diners, restaurants and people who desire to feed them on a regular basis.
Control measures recommended by Hot Foot include Hot Foot Gel, spikes, 2 inch exclusion netting and Electrak electric shock.
STARLINGS (STURNUS VULGARIS)
The European Starling was first introduced to the USA in 1890. 60 birds were brought to New York and today there are estimated to be in excess of 130 million across North America. The wings of the Starling are triangular in shape when stretched out in full flight and their flight path is direct and fast, not dropping and rising like many other birds.
Starlings like to nest in recessed areas however they are quite comfortable nesting on the outer surfaces of major city buildings, ornate columns, steel towers of power companies and Oil Refineries etc. They are a migratory bird and as cold weather approaches (in Fall) then they commence flocking in large numbers. Their diet also switches from insects and fruits to grains, seeds, food in garbage etc.
The typical behavior of Starlings is to ever increasing numbers as they return to their evening roost. When roosting, their droppings contaminate animal feed, such as at cattle feed lots, animal drinking water etc. and they make a considerable mess on sidewalks etc. directly under their roosts. Considerable noise is heard from their calling during early roosting prior to nesting.
Starlings are aggressive nesters; they are known to out compete other native birds for nesting areas and in the process destroy eggs, nests, and even kill nestlings and adults in the process. The female lays 4-7 eggs per brood and these hatch after approximately 11-13 days of incubation. Young birds leave the nest after 3 weeks. 2 Broods per season is not uncommon.
A flock of 2,000 birds can consume between 1 and 2 tons of grain in one month.
Control measures recommended by Hot Foot America include Hot Foot Gel, 1-1/8” exclusion netting, Electrak electric shock. Do not use spikes as these are not effective against Starlings.
SPARROWS (PASSER DOMESTICUS)
The English sparrow was introduced into the USA in the mid 1800’s and it is a member of the Weaver Finch family. They lay 3-7 eggs per brood but most usually 4-5 are encountered. Typically have 3 broods per year. Eggs are laid in any month of the year although most commonly between March-August.
Mortality is quite high during the first year and the majority of birds travel within an area of just over a mile from their nesting spot while young birds are being raised.
As with pigeons, it is usually the male which chooses the nesting site and this is usually in a recessed area protected from predators and other larger birds. Sparrows are aggressive nesters and will drive other native birds out of a selected nesting place. They will kill bluebirds and Swallows while nesting in order to take over the nests and are very aggressive in this regard.
Sparrows are not scared of a close proximity to humans and grassy nesting material can frequently be seen protruding from behind signs, lettering on buildings, in narrow gaps in loading docks etc. Although the Weaver Finch family shows good workmanship in building their nests, sparrow nests are bulky and seem to be built quite roughly.
Frequently they will invade supermarkets, warehouses, factories etc. and will peck out insulation to find and form a nest. Considerable damage results and in many cases their nesting material near light fittings creates a fire hazard.
Damage is caused during feeding by the birds pecking seeds, buds and flowers, vegetables, fruits etc.
Some of the problems they pass to humans include Newcastle Disease, salmonellosis, transmittable gastroenteritis, tuberculosis, etc.
Control measures include Hot Foot America gel, exclusion netting and Electrak electric shock.
|
|
|
|
|
|
|
|
|
TRANSMISSION OF DISEASES FROM BIRDS TO HUMANS |
|
|
|
|
|
|
|
SALMONELLOSIS |
|
|
|
Salmonella live in the intestines of birds and other animals and is transmitted to humans by ingesting food containing this bacteria. Food can also be contaminated by passing the bacteria from our hands which have touched a surface containing this bacteria.
40,000 cases of infection from the salmonella bacteria are reported each year in the USA and 1,000 deaths per annum.
People develop fever, abdominal cramps, diarrhea etc. usually lasting from 4-7 days. Severe cases require hospitalization.
Avoidance: remove birds from buildings especially if they are nesting and dropping faeces on or around air conditioning systems. Wash hands thoroughly if you touch any surface where bird droppings are present.
For more data: www.cdc.gov/od/oc/media/fact/salmonel.htm |
|
|
|
|
|
|
|
ARBOVIRAL ENCEPHALITIDES |
|
|
|
These are viruses which survive through the transmission from host to host by blood suckers such as mosquitoes, ticks etc. They cause encephalitis in humans. Most occur in the period June-September but it is much more extensive in the warmer climate States.
Symptoms include fever, headache, malaise, etc. Some deaths do occur. There is no commercially available vaccine for this virus.
One strain (EEC) occurs in natural cycles involving birds. Grain eating birds such as sparrows, pigeons etc. are thought to play a role in the transmission of the virus (W.E.E.) to mosquitoes then to humans. Mortality rate is approximately 3%.
For more information www.cdc.gov/ncidod/dvbird/arbor/arbdet.htm |
|
|
|
|
|
|
|
ST. LOUIS ENCEPHALITIS |
|
|
|
People develop flu-like symptoms, fever, headache, lethargy etc. Severe cases cause seizures, double-vision, paralysis and death. As many as 30% of elderly people infected with SLE die.
No vaccine is available; No antibiotics are effective; No cure.
This virus occurs naturally in birds however it does not affect them. It is spread from bird to humans by blood sucking mosquitoes type “CULEX” which are very common in the USA.
Prevention is best achieved by removing roosting and nesting birds from buildings where people live and work. Culex mosquitoes are most active between 1 hour before sunset to one hour after sunrise. They breed in fresh water and are prevalent after rain.
For more information www.vicioso.com/health/disease/encephalitis/sle.htm |
|
|
|
|
|
|
|
WEST NILE VIRUS |
|
|
|
Since 1999 this virus has been found in over 80 species of birds, including 60 free ranging species from 20 States. As the virus spreads to more locations in Gulf Coast States, the threat of the virus spreading to Midwestern and Western states becomes greater.
Birds found infected include the Rock Dove (Pigeon).
West Nile Viral infections are rapidly increasing in intensity and distribution in the USA. The southward migration of birds is of particular concern as they will pass through infected States and move the virus to other more Southern States along the gulf Coast. Infected dead birds have been found in 9 new states.
4 human cases have occurred in Florida and 1 death in Georgia. This is in addition to 4 human cases in New York City area, and one in New Jersey. In 2000 there were 21 human cases with 2 deaths and in 1999 there were 62 human cases with 7 deaths.
To protect the health of people, roosting and nesting birds should be removed from properties where people work and live, especially in the Eastern States at the current point in time. Precautions against mosquito bites should also be taken.
For more information www.usgs.gov/public/press/public_affairs/press_releases/pr1109m.html. |
|
|
|
|
|
|
|
HISTOPLASMOSIS |
|
|
|
Histoplasmosis is a fungus which is found in the soil, particularly soil with a high nitrogen content and it is enriched by the droppings of birds and bats. It thrives in warm temperatures and in moist conditions especially in areas such as bird roosts, caves infested with bats, school yards, chicken coops, areas where there is rotten or decaying wood etc. It is contracted when the soil from an infected area is disturbed and tiny spores are inhaled. These spores enter the lungs and can then be transported around the body.
Birds can carry histoplasmosis fungus on their legs, feet, wings etc. but they are not infected with histoplasmosis, most likely because of their high body temperature. However bats do carry and do excrete histoplasmosis. Apart from humans, animals such as dogs, cats, rats, skunks, foxes etc. also are susceptible to this disease.
It is estimated that in n America alone, 50 million people have been infected with this fungus, approximately 500,000 test positive each year and we have about 800 deaths.
It usually appears as mild, flu-like symptoms, chest pain, dry cough etc.
Dust and dirt containing histoplasmosis spores can be carried over a long distance and hence can affect a number of workers on an infected site.
The three largest known outbreaks of Histoplasmosis on record are:
1978; 120,000 people infected and 15 died.
1980; similar to 1978
1988(50% of the cases were AIDS sufferers)
In 1978 the American Journal of epidemiology reported that workers were shoveling excessive bird droppings from the roof of a courthouse to the ground for removal. The dust from this procedure was picked up by the window air conditioners and re-distributed throughout the entire building. Over 50% of the occupants contracted Histoplasmosis and one person had only been in the building for 10 minutes.
Several cases of Cryptococcocal meningitis have been reported where workers exposed to bird droppings have developed a chronic inflammation of the brain tissue. A window cleaner in California lost 50% of his lung capacity because he came into regular contact with bird droppings on window ledges.
People are strongly advised to remove birds from roosting and nesting on buildings especially if they are near air handling systems.
|
|
|
|
|
|
|
|
|
ELECTRIC SHOCK FOR BIRD EXCLUSION |
|
|
|
|
|
|
|
PERFORMANCE DATA |
|
|
|
The use of extremely low direct current/high voltage systems for animal repelling and training is not new. Systems for cattle, Deer, etc. have been around for many years as have smaller products to stop pets such as dogs and cats from loafing on sofas etc. Even smaller systems have been used (and are still used today) to train dogs not to bark or to keep them within a boundary of a property without the need for fences. However, systems for bird control have only been on the market for a relatively small number of years and as such most suppliers have based their development on existing systems.
A truly unique and patented product range is the Electrack system from Hot Foot America. This product possesses all the features which one needs for an effective installation on exterior and interior building surfaces.
• It is able to bend and flex in both the vertical (over curved window tops) and horizontal (around curved balconies and ledges etc.) plane.
• It is so low in Profile that one installed it is virtually invisible from the ground.
• Rolls of 50ft and 100ft length make installations fast, low cost and capable of being installed using adhesives. No holes need to be drilled into the application surface.
• It will not stretch or sag.
Power supply is provided from either a 110 volt plug-in power box (which must be protected from the weather) or a battery which is charged using a solar panel. Several options of battery power are available. Hot Foot have found that for its tracks of up to 600ft in length, one 4 volt battery/solar charger is sufficient whereas for longer installations (up to 1 mile) a 12 volt unit is more desirable.
Power supplies can be remotely mounted from the actual track installation if necessary, however this necessitates that well insulated lead-out-wires be run from the power box to the track.
|
|
|
|
|
|
|
|
PITFALLS TO AVOID |
|
|
|
One of the biggest factors causing electric shock systems to fail to repel birds from a roosting surface is inadequate power to the track. A fully powered shock box should deliver approximately 9000 volts and if this falls below 4800 volts then birds can withstand the shock delivered.
Birds are capable of learned behavior and if the power delivered through the repelling track is too low, they learn to stand behind it and not repelled fro the ledge. Once this happens it is almost impossible to modify the installation so that the birds will leave.
Low voltage can be caused by several factors:
1- Applicators use ordinary 110 volt power cable to run from the power box to the track. Since most power boxes put out nearly 9,000 volts then the insulation of the 110 volt cable is inadequate and leakage occurs from the charged wire to the earthed wire. Only use insulated cable supplied by Companies such as Hot Foot and ensure it has an insulation resistance of at least 9KV.
2 - Poor connections joining one track to another. If these are not giving good transfer of current along the installation then power will be lost.
3 - Some tracks require corner pieces or joining wires to make corners (not the Hot Foot Electrack) and these contribute to power losses.
4 - Debris on the tracks.
5 - Corrosion of the conducting wires. Always choose a product which has stainless steel or some other non-corrosive current carrying wire.
6 - Low input voltage to the power boxes.
7 - A faulty power box.
|
|
|
|
|
|
|
|
TRICKS OF THE TRADE |
 |
|
|
THE LEADING EDGE
It is well known to Companies which are regularly involved in bird control that pest birds always prefer the leading edge of ledges, parapet walls etc. This is attributed to their desire to make a hasty retreat if danger approaches (Hawks) by simply stepping off the ledge and allowing gravity to speed the airflow over their wings. If birds are forced to the rear of a ledge then the only way of escape is upwards and this means the bird has to overcome gravity to gain air speed and maneuverability.
So, clearly the first and most important place to install a repelling system, in this case electric shock, is on the leading edge of the ledge. This is also the most visible portion from the ground looking up so low profile products are most desirable.
When a bird is coming in to land, it does not fly backwards, so it will land and then turn around to face the way it came in. It is in this critical area that you must install your shock system.
THE ACTIVE WIRE
Electric shock systems most frequently have two wires (early systems had three). One wire carries the current from the active terminal of the power box and the other wire is earthed (from the earth terminal of the power box). The birds foot or feet have to make contact with either the active wire and
1 - The earthed wire, or
2 - A good earth
in order for it to receive the shock. Hot Foot America has found that the most effective installations are those where the active wire in the track is the one at the outer most portion of the ledge.
BIRDS' FEET ARE NOT GOOD CONDUCTORS
The foot of the bird does not carry the same nerves as we have in our finger tips. So, what we think is a powerful shock when we touch a track system is not what the bird experiences. We have found that voltages of 3,000-4000 make humans jump yet birds have been seen to stand on track with this voltage and not move. This should be remembered when checking the line voltage in your shock system.
Fit and Test; Fit and Test.
This is the golden rule when installing hundreds, even thousands, of Electrack on a building. Good connections are essential and if you do not identify a poor connection at the time of installation then it is near impossible to find when the job is done. So, follow these step by step instructions for a fail safe job.
1 - Fully charge the battery/solar power box by placing in daylight for two days prior to application. For the USA it should face south.
2 - Mount the power box.
3 - Run lead-out wire from the power box to the place where the first track is to be fitted. You must use lead-out wire that has a minimum 9,000-volt insulation.
4 - When the first section of track has been fitted, attach the lead-out wire and turn the power on. Check the voltage by testing at the power box. You should have approximately 8500.Tests should be carried out using a digital voltage test meter such as those sold by Hot Foot.
5 - If power is low, check connections and look for any short circuits.
6 - Turn power off then fit the second track to the first track. Check voltage as per step 4.
7 - Continue to install track and repeat the procedure of fit-test-fit-test etc. This way, any short circuits or poor connections will be located immediately.
8 - If you are leaving the site overnight, or at any time when birds can land, make sure you connect the work completed to power. Bird droppings are conductive and if allowed to sit on the track can cause a short circuit when the power is turned on.
For more information on Electrack systems, contact your local Hot Foot Representative or Hot Foot directly at (415) 789-5135 or fax (415) 789-0564.
|
|
|
