The Ability of Avian Radars to Track Near Miss Bird Strike Events: A Missing Informational Link

The management of problem wildlife within the airfield environment is a difficult job and today’s biologists require as much information as possible. Bird censuses and actual strike events provide a good picture, but there is a valuable data set out there that has been overlooked, until now. Recent advances in commercially available, digital avian tracking radars have for the first time enabled biologists to track and evaluate near-miss events to increase the safety margin for our pilots and crew. As a part of the Department of Defense, Environmental Securities Technology Certification Program (ESTCP) Project: Integration and Validation of Avian Radars, tens of thousands of hours of bird tracks have been recorded. During the evaluation of many of these tracks, it was discovered that the radar software is capable of tracking and reporting near- miss events between birds and aircraft. This capability has motivated a study to characterize near-miss events and their importance for BASH management. This presentation will discuss the importance of near-miss information and how it can be used to enhance aviation safety. The definition of a near-miss event will be discussed, along with how this type of information can be used as a part of a facility bird strike management program. A review of some archived data sets will illustrate the potential for deriving risk assessments from near-miss information

Population trends of resident and migratory Canada geese in relation to strikes with civil aircraft

Canada geese (Branta canadensis) are of particular concern to aviation in the USA because of their large size, flocking behavior, attraction to airports for grazing, and, for the resident population, year-round presence in urban environments. We documented trends in resident and migrant Canada goose populations in North America from 1970 to 2012, and for 1990 to 2012 examined these trends in relation to trends in reported civil aircraft collisions (strikes) with Canada geese. The overall Canada goose population increased 4.5 fold from 1.26 million in 1970 to 5.69 million in 2012. Most of this overall increase was due to a 15.6-fold increase in the population of resident geese (from 0.25 to 3.85 million), especially during the 1990s when the population increased at a mean annual rate of 12.7%. From 2000 to 2012, the resident population has stabilized, fluctuating between 3.36 and 3.85 million birds. The migrant population has remained relatively stable since 1990, with the population in 2012 estimated at 1.84 million. Resident geese comprised 68% of the total Canada goose population in 2012 compared to 41% in 1990 and 20% in 1970. From 1990 to 2012, 1,403 Canada goose strikes with civil aircraft were reported in the USA, of which 704 (50%) caused damage. The strike rate and damaging strike rate for all geese and for resident geese only (strikes in May to September) increased in parallel with the increase in the total Canada goose population (resident and migratory combined) and resident population, respectively, from 1990 to 1999. From 1999 to 2012, the strike rate and especially the damage strike rate exhibited a downward trend, especially for strikes involving resident geese during May to September. We hypothesize that this decline is due to Canada goose management programs implemented at many airports and in other urban areas

Wildlife at Airports

Collisions between aircraft and wildlife (wildlife strikes) are common occurrences across the developed world. Wildlife strikes are not only numerous, but also costly. Estimates suggest that wildlife strikes cost the civil aviation industry in the U.S. up to $625 million annually, and nearly 500 people have been killed in wildlife strikes worldwide. Most wildlife strikes occur in the airport environment: 72 percent of all strikes occur when the aircraft is ≤500 ft (152 m) above ground level, and 41 percent of strikes occur when the aircraft is on the ground during landing or takeoff. Thus, management efforts to reduce wildlife hazards are focused at the airport. There are many techniques used to reduce wildlife hazards at airports, and these usually work best when used in an integrative fashion. Here, we discuss the available data on wildlife strikes with aircraft, summarize legal considerations, explain why wildlife are attracted to airports and how to identify important wildlife attractants, describe commonly-used tools and techniques for reducing wildlife hazards at airports, and explain how airports can enlist the help of professional wildlife biologists to manage wildlife hazards. Effective management of wildlife to reduce strikes, like all types of wildlife damage management, is based on principles from wildlife ecology, physiology, and behavior. Airport biologists should consider how these disciplines interact in the airport context, particularly with an understanding of regulatory guidance, non-wildlife related airport safety priorities, and strike data. This “marriage” of wildlife ecology with aspects of airport operations will aid in discerning how and why animals respond to various mitigation methods (at both the individual and population levels), why and under what conditions some management tools and techniques work better than others, and allow airport biologists to more intelligently direct management efforts

Modeling the cost of bird strikes to US civil aircraft

The objective of our analysis is to develop a model of damage costs that arise from collisions between aircraft and birds, based on data drawn from the Federal Aviation Administration National Wildlife Strike Database (NWSD). We develop a two-part model, composed of two separate statistical models, that accounts for the effects of aircraft mass category, engine type, component of the aircraft struck, and the size and number of birds struck. Our results indicate the size of bird, number of birds, and engine ingestions are the largest determinants of strike-related costs. More generally, our result is a model that provides a better understanding of the determinants of damage costs and that can be used to interpolate the substantial amount of missing data on damage costs that currently exists within the NWSD. A more complete accounting of damage costs will allow a better understanding of how damage costs vary geographically and temporally and, thus, enable more efficient allocation of management resources across airports and seasons

Estimating Interspecific Economic Risk of Bird Strikes With Aircraft

The International Civil Aviation Organization promotes prioritization of wildlife management on airports, among other safety issues, by emphasizing the risk of wildlife–aircraft collisions (strikes). In its basic form, strike risk comprises a frequency component (i.e., how often strikes occur) and a severity component reflecting the cost of the incident. However, there is no widely accepted formula for estimating strike risk. Our goal was to develop a probabilistic risk metric that is adaptable for airports to use. Our specific objectives were to 1) update species-specific, relative hazard scores (i.e., the likelihood of aircraft damage or effect on flight when strikes occur) using recent U.S. Federal Aviation Administration (FAA) wildlife strike data (2010–2015); 2) develop 4 a priori risk models, reflecting species-specific strike data and updated relative hazard scores; 3) test these models against independent data (monetary costs associated with strikes); and 4) apply our best model to strike data from 4 large, FAA-certificated airports to illustrate its application at the local level. Our best-fitting risk model included an independent variable that was an interaction of quadratic transformed relative hazard score and number of wildlife strikes (r2=0.74). Top species in terms of estimated risk nationally were red-tailed hawk (Buteo jamaicensis), Canada goose (Branta canadensis), turkey vulture (Cathartes aura), rock pigeon (Columba livia), and mourning dove (Zenaida macroura). We found substantial overlap among the top 5 riskiest species locally across 3 of 4 airports considered, illustrating the degree of site specific differences that affect risk. Strike risk is dynamic; therefore, future work on risk estimation should allow for model adjustment to reflect ongoing wildlife management actions at airports that could influence future strike risk. Published 2018. This article is a U.S. Government work and is in the public domain in the USA

THE USE OF RADAR TO AUGMENT VISUAL OBSERVATIONS IN WILDLIFE HAZARD ASSESMENTS

Assessing wildlife hazards to aviation in the airport environment is typically initiated by conducting a Wildlife Hazard Assessment (WHA). Ecological relationships between wildlife populations and habitat are usually discerned through observations during the course of one annual cycle. Although proximate hazards, on the airport, are well defined during the WHA process, off-airport features also can attract wildlife. Wildlife species can transit airport property traveling to and from habitat attractants. During a WHA, common wildlife sampling techniques are employed to determine species, their approximate numbers, and through association an index of potentially attractive habitat. Continuous observations could provide a more complete picture but would require greater sampling effort. Radar is a tool that has demonstrated efficacy to automatically monitor wildlife at greater distances than can be achieved through traditional techniques. Modern systems also have the ability to record a variety of spatial and temporal variables simultaneously and processed data streams can be further analyzed. In association with GIS software, these data can be queried to provide hazard and risk mapping on the airfield and in the approach/departure corridors, as well as the air traffic pattern. The use of radar in combination with traditional wildlife observation techniques could significantly increase the amount of information available for analyses during a WHA. At MCAS Cherry Point we used radar observations to document winter waterfowl movements at night (including migration departures) as well as diurnal bird movements. These movements included incursions into the approach/departure corridors and the initial location of the waterfowl presenting the hazard. Although radar has its benefits, such as detecting wildlife at night and greater distances than can be accomplished visually, it also has its shortcomings. These include reduced sensitivity during heavy precipitation (e.g., X- and K-band radars) and the inability to identify the species of the birds detected

DISPOSAL OF BIO-SOLIDS AT AIRPORTS: INCREASED WILDLIFE HAZARDS TO AVIATION OR NOT?

Airports often times employ different land uses on their airfields to generate or save funds. The application of bio-solids is one such use. Questions concerning this practice and its compatibility with safe aircraft operations arise; however, little information exists concerning this issue. FAA regulations and technical guidance do not currently prohibit this practice on airfields. Marine Corps Air Station Cherry Point, located in North Carolina, has applied treated bio-solids to portions of the airfield over the past 14 years; this program is anticipated to continue into the future. During 2003–2005, we conducted a study to compare plant community dynamics and wildlife use of grassland habitats related to bio-solids application. Airfield plant communities have been significantly altered by long-term bio-solids application. Grasslands where bio-solids were applied were dominated by tall fescue and bahiagrass, whereas plant species diversity was higher in control plots. Overall, bird use of plots appeared to be species-specific and was accented by seasonal differences. During winter months, observations of European starlings, eastern meadowlarks and other flocking birds increased in bio-solid plots relative to control plots. A total of 5 small mammals were captured over 4,000 trap-nights, indicating small mammal populations were similar between grassland areas. Patterns of white-tailed deer use of bio-solid and control plots were spurious; areas of higher deer use were most likely related to other habitat features (e.g., travel corridors). The bio-solids application program does not appear to have created a long-term wildlife attractant. Short-term and seasonal wildlife hazards that might occur can be mitigated through a proactive BASH management program

COLLISIONS BETWEEN EAGLES AND AIRCRAFT: AN INCREASING PROBLEM IN THE AIRPORT ENVIRONMENT

Most known fatalities for both Bald Eagles (Haliaeetus leucocephalus) and Golden Eagles (Aquila chrysaetos) are associated with humans (e.g., collisions with vehicles and artificial structures). Notably, the risk of collisions between eagles and aircraft is an increasing problem at civil airports and military airfields. Of the 234 eagle collisions with civil and military aircraft reported to the Federal Aviation Administration, the U.S. Air Force, and the U.S. Navy during 1990–2013, 52% caused damage to the aircraft. During this 23-yr time period, Bald Eagle–aircraft collisions increased by 2200% and Golden Eagle–aircraft collisions increased by 400%. Eagle–aircraft collisions occur primarily during daylight hours (88%) and typically within the vicinity of the airfield itself; 82.6% of the Bald Eagle–aircraft collisions and 81.0% of Golden Eagle strikes occurred when the aircraft was at or below 305 m aboveground level. Although collision with aircraft is a very minor source of mortality for Golden Eagles, increasing and expanding Bald Eagle populations will likely result in more eagle–aircraft collisions. Currently, there are few mitigation tools and techniques available to reduce eagle–aircraft collisions. Development and evaluation of effective, publically acceptable methods of reducing eagle–human conflicts represent important areas for future research

The National Wildlife Strike Database: A Scientific Foundation to Enhance Aviation Safety

The U.S. Federal Aviation Administration\u27s (FAA) National Wildlife Strike Database (NWSD) documents reports of civil aircraft collisions with wildlife in USA. The NWSD has been managed by the Wildlife Services Program of the U.S. Department of Agriculture through an interagency agreement since its inception. Although the NWSD includes about 170,000 reports of civil aircraft collisions with wildlife (97% birds) from 1990-2015 (14,000 in 2015), the overriding focus has been the quality control of data entered for over 90 variables ranging from species and numbers of wildlife struck, location and time of day, phase and height of flight, aircraft type, components struck and damaged, effect of strike on flight, and associated costs. This attention to detail allows the NWSD to be used in multiple ways to document the nature of the problem temporally and spatially for individual airports and nationwide. The NWSD is used by individual airports and FAA Airport Certification Inspectors to help objectively evaluate and improve Wildlife Hazard Management Plans by examining adverse-effect strike rates (number/100,000 aircraft movements) and the species causing those damaging strikes. The NWSD provides supportive evidence and guidance to state and federal agencies for issuing permits for wetland mitigation and removal of wildlife at airports. Nationally, the NWSD provides a science-based foundation for FAA regulations and Advisory Circulars related to wildlife management at airports and airworthiness standards for engines and aircraft components. In addition, the NWSD provides unique opportunities for basic research on topics such as bird migration (height and location of strikes) and bird behavior in relation to aircraft lighting. For example, recent research has shown that birds are more likely to strike the left side of aircraft where red navigation lights are located. The NWSD is a living document, continuously refined with new and revised strike events to enable improvements to aviation safety in an environmentally responsible, science-based manner