Report on 

Bird Strike Hazards Associated with the Proposed North 

Shore Marine Transfer Station, Queens, New York.

Submitted by:

Ronald L. Merritt

DeTect Inc.
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I. Introduction. In preparing this report I reviewed a number of documents and reports that address the 

potential for the proposed North Shore Marine Transfer Station (MTS) to increase bird strike risk at the nearby 

LaGuardia Airport in Queens, New York. Included in these documents was a report titled “Preliminary 

Assessment and Recommendations Regarding Potential Bird Hazards to Aviation from the Proposed North 

Shore Marine Transfer Station, Queens, New York,” dated May 14, 2010, various maps of the region, FAA bird 

strike data and several other expert reports and analyses. Additionally I participated in a risk management 

workshop held in Phoenix, AZ, on July 14, 2010, to discuss additional risk considerations and implications to 

internationally recognized standards and methods of risk management.

II. Review of the Report: The FAA/USDA report (the report) “Evaluation of the north shore marine 

transfer station and its compatibility with respect to bird strikes and safe air operations at LaGuardia Airport 

(draft)” dated April 2010 is the result of an extremely short assessment of the proposed facility. The hurried 

time line for this effort resulted in an incomplete study, unconventional risk assessment methodologies and 

conclusions that are not substantiated by the report itself. 

1. The study upon which the report relies was conducted due to legitimate concerns that the proposed site 

would pose a significant hazard to safe aviation. This concern is based upon decades of experience 

with birds being attracted to municipal solid waste facilities, including transfer stations. This attraction 

and the subsequent bird strike hazards associated with the attraction led to the development of separation 

criteria and study requirements outlined in FAA Advisory Circular 150/5200-33B.

2. The study period was inadequate. The report states that, “Standardized bird surveys were conducted by 

professional wildlife biologists during February and March of 2010 at the proposed MTS site to gain insight 

into bird activity at or near the proposed building site” (page 13). A standard wildlife hazard assessment for 

airports requires that daily and seasonal movements be determined. Further examination of the report reveals 

a very compressed time-line for this study which began on 30 Nov 2009 and resulted in a draft report 110

days later on March 19, 2010. Without a full seasonal study, it is unclear if these wintering populations 

represent the worst case scenario or if summer populations may increase the density of gulls using the area. 

Reference was made in the report to other long term studies conducted at the airport, but no seasonal data 

were presented to indicate which months had peak activity. 
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3. The study range was limited. A standard wildlife hazard assessment for an airport generally requires 

investigation of bird attractions out to a range of 5 nautical miles from the airport. This is based on the 

general knowledge that gulls and other potentially hazardous species may travel over 10 miles to forage or 

loaf in a preferred area. In the report, the background number of birds was determined from repeated surveys

within a 0.25 mile radius from the proposed MTS site. 

4. Background numbers of hazardous birds. The report identifies three potentially hazardous species of birds, 

gulls (includes all species in the area such as herring gulls and ring-billed gulls), pigeons, and European 

starlings. From those surveys it was estimated that number of gulls in that limited area over 100 per hour

and that less than 1% were actually observed directly on the proposed MTS site. 

5. Risk analysis is unconventional. The risk analysis procedure included in the report uses unconventional 

methods of depicting operational risk assessments. Generally, operational risk is a matrix between the 

probability of occurrence and the severity of outcome, generally divided into 5 categories each. The 

report uses only three categories of hazardous bird activity for each of three alternative scenarios 1. no 

facility present (current condition), 2. proposed facility, and 3. proposed facility with construction 

modifications and wildlife management. The subsequent risk categories, however, are based only upon 

opinion as to what levels of hazardous bird activities would be expected at the site. Yet the study agrees 

that construction of the MTS at the proposed site would increases bird strike risk. The report states, 

“Overall, the highest risk posed to safe aircraft operations by birds would likely occur if a MTS was 

constructed and operated at the proposed site with no consideration of wildlife issues. This level of risk 

would be associated with increased bird movements (primarily gulls) flying to and from the MTS, in 

particular if these movements occurred within the flight paths of aircraft approaching or departing from 

LaGuardia Airport”(page 22). How or why the proposed mitigation measures (building modifications and 

control programs) are able to reduce risk from High to Low is unexplained.

6. Conclusions are unsubstantiated. The report concludes that, “By incorporating modifications to the 

building design, implementing operational procedures, and developing and conducting an integrated wildlife 

hazard management program, the risk of bird strikes could be greatly reduced when compared to the present 

situation (that is, no MTS facility present and no mitigation of wildlife hazards at the proposed North Shore 

MTS site). However it is not clear how this change in risk category was derived. If there are a high number 

of birds in the approach and departure corridor near the proposed MTS site, the airport should already be 
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taking aggressive measures to reduce the risk. How adding a new food source directly at the end of the 

runway and then implementing a routine integrated bird control plan would reduce risk below background 

levels is not explained nor demonstrated.

III. Risk Assessment. After reviewing all available documents, reports, and maps, I conducted an initial risk 

assessment of the proposed MTS. This assessment includes risk identification, risk analysis, and risk treatment 

options.

1. Risk Identification. One of the first components of the risk management process is to identify sources 

of risk, areas of impacts, events, and their causes and their potential consequences. In the case of the 

MTS there are two main components, the MTS facility (and its operations), and the species of birds that 

would be attracted to the facility.

- The species of birds attracted to the facility would include gulls (ring-billed gull and herring gulls would 

be most common, but others may also investigate), European starlings, and rock dove (common pigeon). 

These birds pose a hazard to aviation due to their body mass and or flocking behaviors. There appears 

to be no disagreement among biologists that these are the most species of greatest concern as other 

hazardous species common in the area such as waterfowl (ducks and geese) are not typically associated 

with municipal waste disposal facilities. Gull species are highly adapted to exploit an available food 

source within minutes. This is part of a well known optimum foraging strategy evolved in these birds 

and is easily demonstrated by simply finding an area with a moderate number of gulls present. On July 

30, 2010, I drove to a beach area near my home. At approximately 10:30 CDT I took a bag of potato 

chips out to the beach. For thirty minutes I observed laughing gulls flying overhead and loafing along 

the beach. Over the 30 minute period I observed approximately 25 gulls either standing along the beach 

or flying past in a field of view that was approximately 400 meters. Often there were no gulls to been 

seen in the observation area (figure 1). I opened the bag of chips and simply tossed it into the air. A 

laughing gull came from behind me and before the chip was taken several birds had already flown in 

(figure 2). I opened the bag and spread the remainder of the bag on the beach and within 60 seconds had 

over 100 gulls attempting to get to the chips and the bag (figure 3). It only takes minutes for an 
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Figure 1. Panama City Beach with few gulls

Figure 2. The first chip is down

 Figure 3. Within 60 seconds of the bag of chips being placed on the beach
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available food source to be recognized and exploited by a species highly evolved with this foraging 

strategy and experience in feeding in and around waste disposal areas and vehicles.

- The MTS facility attracts these hazardous bird species. Municipal solid waste facilities including 

transfer stations have the potential to attract large populations of potentially hazardous species of birds 

as the waste stream generally contains a large amount of food. Gulls and other species can quickly 

exploit an available food source within minutes of it becoming available. In the case of the proposed 

MTS food could become available at several points in the disposal/transfer process. Each of these 

points has the potential for industrial “failure mode” to occur which would result in this food source 

being temporarily available. 

- First inbound vehicles moving towards the MTS may periodically fail to be completely covered or 

closed. Waste may also leak from these vehicles. Generally a transfer station operation plan will 

include some level of litter patrol activities to police the roads in the vicinity of the MTS. Gulls are 

quickly attracted to spilling garbage and are accustomed to feeding in and around these areas. 

Additionally these trucks often emit odors that birds will detect and seek to exploit. Another potential 

source of industrial failure would be the breakdown of a full short haul trash truck near the station that 

may sit for hours waiting removal. Such a vehicle may also have exposed debris attached to the external 

portions of the vehicle that would attract gulls to scavenge around it. 

- Outbound vehicles may also have residual debris attached to the truck. While most standards of 

operations require cleaning the wheels and other external components, these wash systems also 

breakdown periodically and trucks may leave the facility with “food” attached.

- Transfer station activities. The transfer station itself has several functions where industrial failure may 

result in large quantities of food becoming available to birds. Doors failing to properly open and close 

may result in temporary access to the tipping floors. Other mechanical failures or personnel delays 

result in vehicles sitting outdoors for extended periods of time, delivery schedules being delayed, trucks 

backing up into holding areas. Compacting equipment, loaders, containers, all have moving parts that 

will break and or fail over a period of time and will result in momentary availability of food. When 

these malfunctions occur, it will only take a few minutes for gulls to find the available food and exploit 
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it. It is unlikely that a trained bird control specialist will always be able to identify the accidental 

availability of food prior to birds finding it. The subsequent dispersal activities will move birds away 

from the site, but only after the birds have arrived at the food source (moved through the critical 

airspace). Following dispersal, the birds will leave the facility and will again move through the critical 

airspace.

- Inbound and outbound Barges. Gulls often follow barges along rivers. Prop wash often stirs up 

invertebrates and other food sources. Garbage barges, even with containers, may have residual debris 

and leakage which attract birds – Residual debris. Inadvertent failure to close doors or door failures 

occur which further invites opportunities for gulls to feed.

2. Risk analysis. Risk analysis includes an estimation of the probability of occurrence of a risk event 

combined with the severity of the outcome should such and even occur. ISO 31000 standards include a 

simple risk matrix (figure 4 below) to assist in organizing these components.

Figure 4. Risk assessment matrix

- Likelihood of occurrence. The report suggests that the proposed MTS would periodically attract 

hazardous bird species to the site. This is supported by the already high strike history with gull species 

R I S K M A T R I X Definitions

Probability (P) Severity (S)

A Very High (VH)

Likely to occur often (to 

be expected)

I Very High (VH)

Death / system loss / severe environmental 

damage / severe financial loss ($10M)

B High (H)

Several times in the 

system’s life cycle

II High (H)

Irrecoverable severe injury / irrecoverable illness / 

major system damage / major environmental 

damage / major financial loss ($5M)

C Medium / Moderate (M)

Once in the system’s 

life cycle

III Medium / Moderate (M)

Irrecoverable light injury / irrecoverable illness / 

relevant system damage / relevant environmental 

damage / relevant financial loss ($1M)

D Low (L)

Unlikely but may 

possibly occur

IV Low (L)

Recoverable light injury / recoverable illness / 

relevant system damage / relevant environmental 

damage / relevant financial loss ($0.25M)

E Very Low (VL)

Practically impossible

(not to be expected)

V Very Low (VL)

Will not result in injury / illness / irrelevant system 

damage / irrelevant environmental damage / 

irrelevant financial loss ($0.075M)

Red: Unacceptable => Must be reduced Yellow: Reduce if feasible, proceed with care Green: Good to go for the time being, keep monitoring
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reported at LaGuardia (55% of all identified strikes were with gull species from 2004-2008). More 

importantly the report identifies La Guardia ranking second highest in reported gulls strikes in the FAA 

Eastern Region with 8.0 strikes per 100,000 movements. The report also states, “Additionally, long-term 

monitoring data collected at LaGuardia Airport (2004−2009), in addition to other studies of birds within the 

New York City area, clearly show that bird activity and abundance within these environments is dynamic 

and likely influenced by several environmental factors, such as weather patterns, tidal cycles and other 

seasonal influences ....”. It is abundantly clear that gulls are not only common in the area, but have 

behaviors that influence their distribution throughout the year that may result in numbers sufficiently 

high enough around the airport to result in bird strike events. The likelihood of a strike would have to 

be rated as high and possibly very high even under current conditions (i.e. without the MTS). The 

addition of the MTS, by consensus of the blue ribbon panelists who wrote the report will increase the 

attraction of the area to gulls. The reasonable conclusion from that position is that the likelihood of a 

gull strike after the construction of the MTS is very high.

- Severity of outcome. Damage to aircraft is a function of aircraft speed and the mass of the bird species 

struck. Ring-billed gulls and herring gulls may weigh up to 2.5 to 3 pounds. Additionally these birds 

commonly move in flocks which dramatically increase the probability of a strike as well as the potential 

for a multiple strike. The severity of outcome of hitting multiple birds with the mass of ring-billed and 

herring gulls would also be rated high to very high.

- Using this standard risk format, the probability of a serious strike would be Very High (A) and the 

severity of outcome would be Very High (I). Clearly the risk matrix would result in an unacceptable 

risk assessment.

3. Risk Treatment Options. Risk treatment involves selecting one or more options for modifying risks 

and implementing those options. In the case of the MTS there are two major treatment options, 

modification to the building and daily operations to minimize perching locations, and feeding 

opportunities and active control or harassment of birds that attempt to feed at the site.
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- Physical – construction to limit perching/roosting: reduce pigeon and starlings, but these birds will 

easily establish perching and roosting/nesting areas in nearby buildings – close by food will continue to 

increase activity in the safety zone.

- Active – active harassment and depredation will only occur on-site and only after birds have passed 

through the airspace. Dispersal will move birds away from the site, but may put them back through the 

airspace and perhaps to the airfield to take refuge. Airport will have to step up gull patrols, and even if 

local birds begin to understand the threat of depredation, migrant birds will still recognize the barges, the 

short haul trucks, and the odors of the MTS.

3. Residual Risk. The risk that remains after treatment options or mitigation have been in place is critical 

to this process. It is this risk that will drive implementation of additional mitigation and oversight or 

change the direction of the overall program. Mitigation of risk must include both the positive and 

negative impacts of the mitigation process. At the proposed MTS risk mitigation is proposed in two 

ways.

- Physical – limiting access through design will have a limited impact as pigeons and starlings will easily 

find roosting and nesting locations in the nearby facilities. Gulls are already plentiful in the area and 

need not linger at the site but merely flyby occasionally to exploit opportunities. Physical constraints 

(that result from revised design) are obviously not 100% effective as it has been suggested in the report 

that active management would be required for an effective program. Therefore sufficient residual risk 

remains after the implementation of design and operational modifications.

- Active- Active control has residual risk components as it is only implemented once increased bird 

activity is identified at the MTS. By the time increased bird activity is observed, birds may have already 

passed through the traffic pattern. Following dispersal these birds will leave the area for some period of 

time. During their departure they are likely to fly through the traffic pattern and may take refuge on 

airport property. So, while active control reduces the number of birds feeding on waste at the MTS it 

also has the negative effect of having to wait until birds arrive on site (pass through the airspace) and 

drives them back into the airspace upon dispersal where they may seek refuge in a nearby open field or 

river (possibly the airport). Further, dispersal activities would have to be carefully coordinated with air 
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traffic control officials at La Guardia to insure birds were not dispersed into the path of arriving or 

departing aircraft. Further, active control mitigation relies heavily on human factors. Bird control staff 

must be specially training to recognize and coordinate bird dispersal efforts. Keeping trained and 

motivated staff is difficult when the risk events occur at low frequency on a daily basis. 

IV. Summary. There is complete agreement among the biologists involved in the assessment of the proposed 

MTS that this facility has the potential to increase hazardous bird activity at the site and in the local area around 

the site. The disagreement is in how effective mitigation efforts might be over the life-cycle of the MTS 

facility. Industrial accidents and failures are not as rare as once thought and conventional risk management 

practices based upon normal distributions of risk probabilities have been shown to be poor predictors of 

catastrophic events. It is highly likely that over the life of the MTS mistakes will be made and accidents will 

happen. The unfortunate consequence of one of these mishaps would be a rapid response of gulls to the site to 

exploit food resources while posing a significant threat to aviation safety. The potential for this rapid response 

is underscored by survey data recorded from the area and strike reports at LaGuardia which clearly indicates a 

robust population of gulls nearby. Mitigation can only take place at the facility after birds have been attracted 

to the site, and eventuality that is so likely that the experts highly recommend a full time bird control staff be 

present along with extensive monitoring and oversight. Once at the site, a carefully coordinated dispersal 

procedure would be required to remove the birds from the MTS facility while avoiding inbound and outbound 

aircraft. The construction of the MTS poses a real threat to aviation safety at LaGuardia and all efforts should 

be made to find a more suitable location. If this facility can be safely built and operated at this location, then 

separation criteria are no longer meaningful.