Cities As Interfaces of Zoonotic Hazard Emergence: Development of the New York City Tick and Wildlife Urban Surveillance System

We investigate how urbanization and wildlife drive tick-borne hazards to understand pathogen transmission dynamics and public health risk. This protocol will fill a gap in our understanding of the role of wildlife in tick-borne diseases. Both of these fields have very specific standardized methodologies, which have not been so far connected in such a way that we can understand how wildlife communities impact tickborne diseases in urban areas.

After selecting the urban wildlife and tick surveillance sites, organize all the required equipment and ensure that there are enough wildlife cameras, memory cards, locks, and lock boxes available for each deployment. Prepare enough fresh batteries, ensuring that each wildlife camera has a complete set of new batteries installed. Most wildlife cameras require six to eight AA batteries.

For each upcoming wildlife camera deployment, confirm that all data from the previous season have been downloaded from the memory cards and properly saved. Create a label that includes a brief project description and contact information such as a permanent project email address. Print the label and attach it securely to the top of each wildlife camera lockbox using clear packing tape.

Label each wildlife camera with a unique camera ID number. Then label an SD card with the same camera id, ideally associating it with the site name. Set the correct date and time on each wildlife camera trap.

Adjust the settings on each wildlife camera to use multi-shot mode with three photos, a 30 second delay between captures, a 24 hour operating period, and a minimum image resolution of 16 megapixels. During the site visit, select trees within 50 meters of the randomly generated point that are suitable for wildlife camera placement. After selecting a suitable tree for camera placement, remove any large grass blades, leaves, or objects that could obstruct the camera's field of view and interfere with its sensors which have a detection distance of up to 80 feet.

This reduces false triggers caused by wind movement. Place the wildlife camera at knee height approximately 50 centimeters in a location that is hidden from trails, angle the camera away from areas of human traffic, such as trails or walkways to minimize human detections. Avoid placing the camera facing directly east or west to prevent sun glare.

Then check that the wildlife camera is aligned parallel to the ground. Deploy wildlife cameras at each selected location for at least 28 days, ensuring that deployments occur during January, April, July, and October to capture seasonal variation in wildlife habitat use and occupancy. Prepare all the required materials for the tick drag procedure.

While wearing disposable laboratory gloves such as latex or nitro gloves, fill two to three vials per plant transect with a minimum of 500 microliters of either 85%ethanol or RNA DNA shield. Next, print enough data sheets to correspond to each planned transect. Place all tick collection materials including forceps, permanent markers, prepared vials, clear plastic tape for collecting abundant larvae, and a writing utensil for note taking into a fanny pack for field use.

Prepare one fanny pack per field data collector. Estimate each field data collector's step length by having them walk a 10 meter transect three times, and then calculate the average step length. For personal safety During tick collection, prepare light colored long sleeved clothing such as white coveralls to improve the visibility of ticks on personnel.

At least 24 hours before field tick collection, treat clothing and shoes with insecticide products containing 0.5%permethrin and let them dry. Before arriving at the field site, tuck pants into socks to prevent tick entry. Allocate 30 minutes to one hour to complete each 100 meter transect, adjusting the time as needed based on tick density.

Record the details including the time of day and weather conditions such as temperature, wind, and relative humidity using a weather meter. Note the latitude and longitude coordinates at the start of the transect using a phone or GPS device with at least 10 meter accuracy. Next, spread a one by one meter white corduroy or flannel drag cloth across the ground, ensuring that it is completely unfolded and maximally in contact with the forest floor or lawn.

Slowly walk a distance of 10 meters while dragging the cloth behind, then stop to inspect the cloth for ticks. Examine the cloth carefully for ticks by placing it under a light, scanning systematically from left to right and top to bottom and watching for any movement. Use forceps to collect all visible ticks and place them into 1.5 Milliliter vials pre-filled with 85%ethanol or RNA DNA shield.

Use a separate vial for each 100 meter transect and label it with a unique transect number. If abundant larvae are found on the cloth, collect them using clear packing tape. At every 10 meter interval along the transect record the number of ticks collected on the data sheet.

Record the dominant vegetation type in each 10 meter segment such as leaf litter, unmaintained herbaceous vegetation, or maintained grass. Finally, at the end of the 100 meter transect, inspect both sides of the drag cloth again for ticks and record the end time and GPS coordinates before moving to the next transect. Identify and record the species and life stage of all collected ticks following taxonomical keys for common ticks.

The Urbanization Gradient Transect was designed to span three counties from New York City through Long Island in New York. All wildlife camera and tick collection sites were placed in public parks, golf courses, cemeteries, nature preserves, and public gardens. Across the urbanization gradient, the selected wildlife camera sites captured the mean and spread of impervious surface cover, housing density, and tree canopy cover within a two kilometer radius.

Tree canopy cover within 100 meters of wildlife cameras showed variation within each transect segment indicating similar local habitat quality across the transect. Field data collection over two sampling years resulted in 4, 928 Wildlife camera trapping days and captured 3, 421 nymphal Blacklegged ticks, 575 nymphal Lonestar ticks, and 329 nymphal Longhorned ticks. Wildlife cameras recorded 34 unique species, including 16 mammals and 16 birds with seven meso mammals consistently observed across sites.

Functional connectivity was the strongest predictor of white-tailed deer occupancy probability, showing a steep increase in predicted occupancy above a threshold value. Higher white-tailed deer occupancy significantly predicted a higher abundance of nymphal Blacklegged ticks. This protocol allows researchers to simultaneously study tick-borne hazards and wildlife host dynamics across an urbanization gradient.

A key challenge to consider with our protocol is the large effort required to maintain the transect and the dependence on partner engagement. After establishment of the transect, additional factors such as social or abiotic could be evaluated to assess the influence on tick-borne hazards and wildlife.