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Annual Mammalian Predator Surveys Completed for Bobwhite Quail Restoration Initiative

Based on years of research conducted by Quail Restoration Initiative project collaborator Tall Timbers Research Station (Tall Timbers), “both avian and mammalian predator populations have increased across the bobwhite’s territory at the same time that bobwhite populations have declined. However, the increase of mammalian predators appears to be greatest” (Palmer, 2000). This group of species, often called mesomammalian predators or meso-predators (i.e., medium-size carnivores) are known to be significant predators of bobwhite quail and their nests (Stoddard 1931, Rollins and Carroll 2001). These meso-predators include: red and gray fox, coyotes, raccoon, opossum, skunks, as well as feral/free-ranging cats. These species also are considered generalists, with a broad diet and habitat requirements (Palmer, 2000).

One of the ways to collect mammal predator abundance data is to perform scent station surveys. These surveys utilize a fatty acid scented bait tablet which attracts mammals to an area where their paw tracks can be identified and recorded. These tablets do not pose a hazard to the animal and are obtained from the United States Department of Agriculture - Animal and Plant Health Inspection Service.

In 2015 as part of the Quail Restoration Initiative, NJ Audubon performed two rounds of mammalian predator abundance surveys utilizing scent stations. These surveys will be conducted on an annual basis for each year of the study.  The goal of these surveys is to establish a baseline for mammalian predator abundance for comparison against future surveys at the study site and for comparison to other study sites. This data will be important for evaluating if meso-predators are a possible limiting factor to re-establishing Northern Bobwhite at the project site.

Utilizing the methodology developed by Tall Timbers, New Jersey Audubon distributed a series of random scent stations across the project site at least 500-yards apart along linear travel lanes such as unimproved roads and fire Researcher Evan Yunker collecting predator data from Scent station(PARKE)breaks. Stations were placed in accessible areas, clear of vegetation, on alternate sides of the lanes within about 5-yards of the lane edge. At each scent station a 1-meter diameter circle was cleared of vegetation to expose the ground surface, which for the subject property was sand. The sand within the circle was broken up to make it loose and then smoothed with an application of animal grade light mineral oil in order to improve animal track impression. One fatty acid tablet (FAS) was then placed in the center of each station and left overnight. The following morning each station was surveyed for tracks. If the station was visited by an animal, the tracks were identified and recorded by the researcher and the sand was made smooth and the FAS tablet replaced if needed. Each survey (one performed during the nesting season in June and one performed in the fall in October) was done for a period of five continuous days. Once all data (track identification) were collected and compiled a calculation was run to determine a percentage value of mammal visitations to the station. This index score provides insight into the mammalian predator community on the property and may provide some guidance as to relating mammalian predator context to bobwhite demographics.

Results of the Predator Abundance Surveys at the Pine Island Cranberry Burlington County, NJ Pinelands Site

Survey Period

Total Amount of mammal visitations at stations

Predator Index Score

Fox (spp)

Eastern Coyote

Raccoon

Virginia Opossum

Striped Skunk

Weasel (spp)

June 2015

35

26.9%

12

13

1

0

6

3

October 2015

37

28.4%

15

5

5

4

2

6

tracks in scent station (PARKE)No other mammalian predator tracks or evidence were encountered during the survey periods, including feral/ free range cats or dogs, bobcat, black bear or mink. For both surveys period, NJA surveyed 26 scent stations at Pine Island for 5 straight days –no rain nights. NOTE: Tall Timber’s research was developed on areas with good to excellent habitat over most of the property. Therefore, other indications of bobwhite population growth should be considered along with this protocol.

According to Tall Timbers’ research: If visitation rates are below 10%, data suggests predation is not a limiting factor on the property. If visitation rates are between 10 and 20%, then depending on habitat, predation may be limiting in some years. However, predation is probably not providing enough pressure on the population to stop the bobwhite population from expanding. If visitation rates greatly exceed 20%, Tall Timbers’ research suggests the bobwhite population may be limited by predation.

Based on the results of the first year of mammalian predator abundance surveying at the Pine Island Cranberry Project site, mammalian predator visitation did not greatly exceed the 20% threshold therefore it is most likely that mammalian predation is not a large concern at the current time at the Pine Island site as far as having a significant impact on the bobwhite population from expanding. Additionally, no evidence of feral/free range cats were detected during survey both survey periods, nor have any, or evidence thereof, ever been observed on the Pine Island site during all telemetry field work conducted throughout the year. This is significant when comparing results from other predator surveys conducted by NJDFW at four separate Wildlife Management Areas (WMA) in Cumberland County designated as Quail Focal Regions. Results from those MWA surveys indicated that feral/free-ranging cats made up approximately 14.81% of the total visitations for the survey periods. According to the NJ Northern Bobwhite Action Plan (NJDFW, 2011), “domestic cats caused 10.1% of total bobwhite mortality in NJ.”

For comparison to the Pine Island surveys, below are the 2015 mammalian predator survey results conducted by NJDFW utilizing the same methodology at the four separate Wildlife Management Areas (WMA) in Cumberland County, NJ.

Results of the Predator Abundance Surveys at NJDFW Cumberland County MWAs

WMA Focal Area Number

Survey Period

Total Amount of mammal visitations at stations

Predator Index Score

Fox (Spp)

Eastern Coyote

Raccoon

Virginia Opossum

Striped Skunk

Feral / Free Ranging Cat

1 Dix WMA

June 2015

28

70%

7

1

7

3

5

5

1 Dix WMA

October 2015

22

55%

3

1

5

7

4

2

2 New Sweden, Nantuxent, Fortescue, Egg Island WMA

June 2015

17

34%

1

0

9

3

1

3

2 New Sweden, Nantuxent, Fortescue, Egg Island WMA

October 2015

24

60%

7

2

8

2

2

3

3 Buckshutem WMA

June 2015

7

17.5%

0

0

0

3

1

2

3 Buckshutem WMA

October 2015

12

30%

1

1

2

6

0

2

4 Millville WMA

June 2015

11

22%

2

3

2

2

2

0

4 Millville WMA

October 2015

15 37.5% 1 1 3 5 2 3

No other mammalian predator tracks or evidence were encountered during the survey periods, including weasel, bobcat, black bear or mink. All Cumberland County WMA Surveys were conducted by NJDFW staff. Surveys stations and surveys days varied per WMA. For June surveys: Area #1 had 10 stations surveyed for 4 days, Area #2 had 10 stations surveyed for 5 days, Area #3 had 10 stations surveyed for 4 days and Area #4 had 10 stations surveyed for 5 days. For the October surveys, Area #1 had 10 stations surveyed for 4 days, Area #2 had 10 stations surveyed for 4 days, Area #3 had 12 stations surveyed for 4 days and Area #4 had 10 stations surveyed for 4 days. NOTE: Tall Timber’s research was developed on areas with good to excellent habitat over most of the property. Therefore, other indications of bobwhite population growth should be considered along with this protocol.

It should be understood that this technique is still considered experimental and data obtained from it should be used as a general guide only for relating mammalian predator context to bobwhite demographics. It does not include avian or reptilian predator abundance or impacts.

Additionally, many other factors such as weather, land use and land cover type, including but not limited to: proximity to row crop (grain) or livestock agriculture, hardwood lowlands and development, can influence the results. Furthermore birds like Northern Bobwhite quail often experience “boom or bust” reproductive cycles based on the impacts of weather and habitat conditions. These cycles are tied to the availability of suitable habitat for survival, nesting, hatch success, among other factors, and are believed to directly connect to the disturbance of habitat that a particular site might experience. At the Pine Island project site disturbance largely means the frequency of fire, although other disturbance mechanisms (such as forestry practices) are utilized to mimic the role of fire in an ecosystem.

bobcat with cardinal DWGNRA (Parke)It is important to recognize that predator-prey relationships are one of the most complex and essential interactions in ecological communities. In the context of the Bobwhite Quail Restoration Initiative for NJ maintaining an ecologically functioning predator community is very important and therefore mammalian predator abundance is only one of several factors to assess for Northern Bobwhite population recovery. Regardless of predation impacts, it is the absence of suitable, connected, high quality habitat that still remains the most significant obstacle to overcome so Bobwhites can meet all their life needs while avoiding predators and surviving periods of severe winter weather (NJDFW, Aug 2011).

 

To find out how you can help support the Bobwhite Quail Restoration Initiative to bring back this iconic species of NJ’s natural heritage please see bobwhite.njaudubon.org

 

 

All photos by John Parke

 

References:

Brennan, L. A. 1999. Northern bobwhite Colinus virginianus. In The birds of North America, no. 397, ed. A. Poole, and F. Gill. Philadelphia, Pennsylvania: The Birds of North America, Inc

New Jersey Division of Fish and Wildlife 2011, NEW JERSEY NORTHERN BOBWHITE ACTION PLAN (Revised Aug 2011) - A Report to the New Jersey Fish and Game Council on the status of and management recommendations for northern bobwhite (Colinus virginianus) in New Jersey

Palmer, W. 2000, Measuring the Predator Context on Your Land to Manage Predation of Bobwhites. Tall Timbers Research Station

Rollins, D., and J. P. Carroll. 2001. Impacts of predation on northern bobwhite and scaled quail. Wildlife Society Bulletin. 29:39–51

Sloan, J. 2015, NJDFW, Mammalian Predator Survey Results – Bobwhite Quail Focal Areas –Cumberland County, NJ

NJ Audubon Has Great Success with Conservation Practices in NJ Highlands

The New Jersey Highlands provides approximately 770 million gallons of potable water daily. Over five million people rely on the Highlands for their Highlands_NJ_short_WebtQual_Page_1drinking water. Also the Highlands Region contains rich agricultural lands and rare natural communities that support many mammals and birds, including 19 breeding bird species of conservation concern, six federally listed threatened and endangered species, and harbors regional strongholds for rare reptiles and amphibians.

Through funding support from the William Penn Foundation and the National Fish and Wildlife Foundation as part of the Delaware River Watershed Initiative, below are just some of the highlights of New Jersey Audubon Stewardship Department’s work in 2015 in the Highlands Region.

Highlands Region Delaware River Watershed Initiative – New Jersey Audubon

1. Acres with Agricultural Best Management Practices (BMPs) implemented (i.e. cover crops):  433

2. Acres of wetlands restored: 25

3. Acres of upland restoration (grassland): 75

4. Acres of forest enrolled into Forest Stewardship Planning: 76

5. Miles of riparian area restored:  4.34

6. Sites receiving phytoremediation native plantings:  3

7. Number of 12’-16’ native trees planted: 380

8. Installation of native willow stakes:  6,500

9. Wildlife boxes (blue bird & wood duck nest boxes and bat roosting) installed: 53

Below are “Before” and “After” restoration photos for the conservation work done in 2015 and some species that will benefit.

Slide3020

Slide2P2280008

Slide6Male Bobolink MC(Parke)

Photos by John Parke