Determining the risks associated with scavenging raptors to the biosecurity of broiler farms on Delmarva.

Final Report for ONE14-215

Project Type: Partnership
Funds awarded in 2014: $11,307.00
Projected End Date: 12/31/2016
Region: Northeast
State: Delaware
Project Leader:
Dr. Brigid McCrea
Delaware State University Cooperative Extension
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Project Information

Summary:

The goal of this study was to determine which scavenging raptor species visit farms, which type of vulture is seen most often, the time of day at which vultures were most often seen, and what other species visit the composters.   The scavenging raptor most often seen on the farm was the Turkey Vulture and they were most often seen in the morning hours of sunrise to 9 am.  Farmers reported seeing vultures on their manure structures most often.  Feral cats were quite commonly seen at the composters as well.  Farmer scouting data was analyzed and presented to both farmers and at a national poultry science conference.  Information from the study was used to add to the curriculum at New Grower Workshops.  One such workshop was attended and data was collected on the farmer’s understanding of the laws surrounding wild birds (including scavenging raptors).  While the farmers grew to understand the laws concerning the shooting of wild birds, they were still very uncomfortable around aggressive birds that did not retreat upon approach and as inclined to shoot them as before.

Based on the results of this research, the Natural Resources and Conservation Departments in both Delaware and Maryland are considering allowing farmers to put screened lids onto composters to deter vultures and other birds of prey from scavenging from composters.  Outreach was accomplished at multiple farmer meetings in Delaware and at a national poultry conference.

Introduction:

For many years, here on Delmarva, broiler chicken farmers have seen an increase in the number of scavenging raptors (Turkey and Black Vultures) that visit their composters. Composters are used to compost the broiler mortality during grow-out rather than using incineration (causes air pollution), burying (due to high water table), or using a rendering service.   The composting systems used by the majority of growers include both bay and channel type.   These compost management systems have proven to be an excellent sustainable system of handling the mortality associated with broiler production.  Many producers have suggested the shooting of the raptors and hanging of dead raptors as a deterrent.  Producers have no wish to bring a lawsuit upon themselves and so require education regarding the Migratory Bird Treaty Act of 1918. 

Project Objectives:

Scouting Study:

We will train 10 broiler producers to scout, identify and count vultures at the composters for 5 minutes three times a week. This scouting will take place from June 2014 to March 2015. We will provide producers with a journal into which they will place their data and recordings. The journal will contain a raptor ID sheet to assist producers in making accurate identifications. Also, general weather observations will be included in the journal.

            The scouting skills will be taught to the producers by the extension agents involved in the project. Using the outreach methods currently in place on Delmarva, producers will be asked if they are interested in participating in the study. The farmers will send in their scouting data to the researchers on a monthly basis. The data will be input by a student and analyzed by the extension poultry specialists.

            When the extension poultry specialist visits with the producers on their respective farms, they will assess the quality of the composter prior to teaching scouting skills. Using a temperature probe as well as accepted visual assessment techniques, the compost management will be rated. The ratings will be either good, average, or poor. Once the scouting period is finished, the composter on each farm will be assessed using the same techniques in order to determine if there has been any improvement. It is expected that farmers, by spending more time near the composting area, will improve their composter management, if needed. In addition to the data collected from scouting, we will, at the end of the study in 2015, ask farmers to complete a post-experiment form to provide constructive criticisms and suggestions about how the project could have been done better, and to indicate what went well.  

 Curriculum Change:

The curriculum will be added to the already well-established waste management and compost management programs presented by both the Maryland and Delaware extension poultry specialists. Broiler producers are required to obtain continuing education credits to maintain their nutrient management certification. The new curriculum will include information on bird ecology and also the laws regarding migratory bird species. The data obtained from the scouting and game cameras will be presented at grower meetings throughout Delmarva.

Cooperators

Click linked name(s) to expand
  • Mary Lou Brown
  • Bill Brown
  • Paul Chesnik
  • Dr. Jon Moyle
  • Jenny Rhodes
  • Kimber and Kimberly Ward

Research

Materials and methods:

Trial 1-Scouting Study: We trained broiler producers to scout, identify and count vultures at the composters for 15 minutes weekly.  We provided producers with a journal into which they will place their data and recordings.  The journal contained a raptor ID sheet to assist producers in making accurate identifications.  Also, general weather observations were included in the journal.  

            The scouting skills were taught to the producers by the extension agents involved in the project.  Using the outreach methods currently in place on Delmarva, producers were asked if they are interested in participating in the study.  Farmers were selected to participate in the scouting study and were trained by the extension poultry specialists.  The farmers sent in their scouting data to the researchers on a monthly basis.  The data was input by a student and analyzed by the extension poultry specialists.

Trial 2-Game Cameras:

We placed game cameras on the farms of participating producers, focusing the cameras on the composter. The game cameras were set so that they take a photo every 5 minutes and they were also motion activated.   The SD cards on the cameras were replaced weekly.  The birds from the game cameras were identified and counted by a student and the data was analyzed by the extension poultry specialists.  Data with regard to season, temperature, and composter management was correlated to the number and species of raptors present. 

 

Curriculum Change:

The curriculum was added to the already compost management programs presented by both the Maryland and Delaware extension poultry specialists. The new curriculum included information on bird ecology and also the laws regarding migratory bird species.  Pre- and post-tests were used to determine the effectiveness of the teaching the new curriculum.  The data obtained from the scouting and game cameras continues to be presented at grower meetings throughout Delmarva.

Research results and discussion:

There were a total of 318 viewing days for the game camera data.  Overall, Turkey Vultures were seen more often (59% of days; n=187) than Black Vultures (14% of days; n=44). This was confirmed by both game camera and farmer scouting data. 

28% of the game camera days (n=89 days) yielded unrecognizable vulture species, while 21% (n= 66) of the days yielded no vulture sightings.

Vultures were seen in their largest numbers in the morning hours of sunrise to 9 am followed by the afternoon hours of 2 to 5 pm.

Farmer scouting indicated that vultures were most often seen atop the manure structure (27.7%).

The most common mammalian specie to visit the compost pile was the feline.  Almost 1/3 of the game camera days identified cats whereas farmers often note only occasionally seeing cats on the farm.  Other species seen include hawks, eagles, deer, raccoons, fox, and domestic dogs. 

All farmers had composter quality and temperature of good and it remained good until the end of the trial.  It did not appear that the quality of the compost affected the numbers of vultures seen on the farms.

Four broiler producers completed scouting on their properties. Most indicated that scouting more often than once a week was too much for them to do and therefore did not scout more often than that.  A student was hired to input survey data. Regularly scheduled meetings for the summer and fall of 2015 were cancelled pre-emptively in anticipation of an outbreak of Avian Influenza on the east coast of the United States.

 

Research conclusions:

At the meeting in Denton, MD in December farmers were given a pre- and a post-test to determine knowledge gained with regard to vultures on broiler farms. Based on the responses below, it appears that the majority of attendees had seen vultures on broiler farms and have heard other farmers talking about seeing vultures on broiler farms.

The results are as follows for two question on the PRE-TEST:

Have you ever seen vultures on a broiler farm? (Multiple Choice)

 

Responses

 

Percent

Count

Yes

83.87%

26

No

16.13%

5

Totals

100%

31

Have you ever heard other farmers talk about seeing vultures on a broiler farm? (Multiple Choice)

 

Responses

 

Percent

Count

Yes

82.76%

24

No

17.24%

5

Totals

100%

29

 

 

 

 

The results are as follows for two specific question on the PRE-TEST and POST-TEST, which was given before and after the presentation on vulture ecology and laws regarding wild birds:

 

What are you permitted to do to remove vultures from your farm? (Multiple Choice)

 

Pre-Test

 

Post-Test

 

Percent

Count

 

Percent

Count

Shooting

17.86%

5

 

19.23%

5

Trapping

10.71%

3

 

3.85%

1

Live capture

0%

0

 

0%

0

Poisoning

0%

0

 

0%

0

Egg Addling

0%

0

 

3.85%

1

All of the above

3.57%

1

 

3.85%

1

None of the above

67.86%

19

 

69.23%

18

Totals

100%

28

 

100%

26

 

What laws govern the rights of wild birds? (Multiple Choice)

 

Pre-Test

 

Post-Test

 

Percent

Count

 

Percent

Count

The fish and wildlife service

76.92%

20

 

3.23%

1

The migratory bird treaty act of 1918

19.23%

5

 

90.32%

28

The passenger pigeon council

0%

0

 

3.23%

1

The ornithological act of 1950

3.85%

1

 

3.23%

1

Totals

100%

26

 

100%

31

These results indicate that the number of people who were willing to shoot vultures do not appear to be swayed by the information provided by the programming, however all appear to have a much better understanding of the laws that govern the rights of wild birds. Based on conversations with farmers after the meeting, they really do not like the birds if they do not fly away from the composters when the farmers pull up in their tractors or vehicles.  Birds that hiss, behave aggressively toward farmers, and remain at the composters are the main reasons stated by farmers as to why farmers feel uncomfortable around the birds.  As explained in the curriculum, it is illegal for farmers to shoot the birds, even if they are made uncomfortable by the presence of the vultures.

Based on the results of this research, the Natural Resources and Conservation Departments in both Delaware and Maryland are considering allowing farmers to put screened lids onto composters to deter vultures and other birds of prey from scavenging from composters.

Participation Summary

Education & Outreach Activities and Participation Summary

Participation Summary

Education/outreach description:

The results were presented at 2 professional meetings.  An abstract for a poster on vultures at Delmarva composters has been accepted for presentation at the International Poultry Scientific Forum to be held in Atlanta, GA on January 26-27, 2015.  A similar abstract, but on the topic of farmer scouting, was accepted for a poster at the Poultry Science Association Conference in Louisville, KY on July 27-30, 2016.

One newly created broiler field day, held on October 31, 2014, was attended by 250 broiler farmers and both Drs. McCrea and Moyle, as well as Mr. Brown and the student, were in attendance to answer questions about the project.  A poster about the project was on display at the field day and the results to date were discussed with broiler farmers.

On January 16, 2015, Dr. Moyle and the student presented the preliminary data from the project to 150 farmers at the 2015 Delaware AgWeek Commercial Poultry Session. This was an all-day event aimed at providing information to growers on topics both timely and pertinent to their operations.

The data obtained from the scouting and game cameras were presented at a New Grower meetings meeting for 30 people in December 2015 in Denton, MD.  This is also the first meeting where the study results were added to the curriculum.   The results continue to be shared at ongoing grower committee meetings on Delmarva.  The curriculum change is shared with all new and incoming producers.

 

Project Outcomes

Project outcomes:

N/A

Farmer Adoption

N/A

Assessment of Project Approach and Areas of Further Study:

Areas needing additional study

It was made clear by our game cameras that additional species visit the composters, mainly at night.  Cats were most often identified.  These land-based scavengers easily roam from farm to farm in certain areas of Delmarva, due to the close proximity of farms to one another.  This is a biosecurity risk that has yet to be addressed.  During an outbreak event, the potential for a scavenger to track a disease to another farm is potentially high.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.