Ox Cart Lane, Lower Wells
Description: Ox Cart Lane is located on the WebhannetRiver, just inside WellsBeach in southern Maine. This site is in the Lower Wells Division of Rachel Carson National Wildlife Refuge. It consists of 60,973 sq meters of tidal creek located at the end of Ox Cart Lane. In this area approximately 90% of the muddy WebhannetRiver bottom is exposed at low tide. Human disturbance at this site is relatively low and the area is protected for wildlife by Rachel Carson NWR. Access to refuge sites, including all saltmarsh, is restricted and advance permission with refuge personnel is required.
Kate O’Brien, wildlife biologist for Rachel Carson NWR, has provided shorebird survey data from Ox Cart Lane. The most common species from 2004 peak survey count data are: SEPL (250), LEYE (15), GRYE (40), WILL (15), SESA (208), LESA (75) and PEEP (250).
Access: To reach this site, take Mile Road heading east off Route 9. The intersection of Route 9 and Mile Road is less than a mile north of the village of Charles Chase Corner. Coming down Mile Road, you will see the Ox Cart Motel on the left. Follow Ox Cart Laneuntil it becomes a dirt road. Stop where the dirt road ends and park. Walk to the top of the rise where there is an old foundation and survey to the north. Then survey the area from the vantage point of the muddy ramp on the left. Walking further down the dirt road takes one to the marsh edge and the south point of the survey area.
Visibility on the mudflats is good, but in the saltmarsh, it is reduced due to light conditions and vegetation height. According to Kate O’Brien, surveyors would do well to begin with the north section first and then count from the southern point, looking north/northeast.
Survey Method: Ground surveys should be conducted within two hours of low tide by driving to the end of Ox Cart Lane. Park your car and walk to the top of the hill with the old foundation. After the northern section is surveyed, walk down the dirt road surveying birds in the southern section of the river bottom and marsh. Use caution so as not to flush birds. Surveys of this area should take less than one hour. A spotting scope is a must.
Selection Bias:The larger marsh at this site is partly obscured by tall grasses and birds foraging along the margins may not be visible from points along the road.
Measurement error: This can be a problem when viewing and counting distant birds, such as yellowlegs, which are visible at greater distances than small “peeps.” A pilot study is needed to establish how measurement error varies among species at this site.
Measurement bias: Future management and/or restoration of the marsh involving vegetation removal could result in bias over time. To determine the extent of such bias, changes in vegetation from year to year should be documented. Additionally, the vantage points for counting shorebirds may have to be adjusted between surveys if viewing conditions change in response to vegetation growth.
Pilot Studies: Low detection rates may result from visibility problems; detection rates should be calculated to adjust surveys accordingly.
Local Contacts:Kate O’Brien, Wildlife Biologist, Rachel Carson National Wildlife Refuge (207) 646-9226