The following was taken from the 2008-09 Annual Habitat Work Plan, Rhode Island National Wildlife Refuge Complex. For an explanation of the larger context for the following management actions, click on this link to the national Strategic Habitat Conservation/Landscape Conservation Cooperatives.
2008 Management Actions
Refuge beaches, above the high tide line, were closed to the public in early April following the guidelines in the 1996 Piping Plover Atlantic Coast Population Revised Recovery Plan. In addition, habitat on local beaches was symbolically fenced to protect nesting birds, as per the cooperative agreement with the RI Department of Environmental Management (DEM), and Memoranda of Understanding (MOUs) for these sites. All beaches were walked 2-3 times per week to locate nesting piping plovers and then monitored daily during incubation and chick rearing to document reproductive success of each pair.
At all of the beaches that successfully fledged at least one chick, the fledging rate exceeded 50%. Trustom Pond had the highest chick survival rate at 88%, followed by Quonochontaug at 79%, and East Beach in Watch Hill at 69%.
Least Tern nesting sites were surveyed two to three times per week starting in April. Active sites were roped off with symbolic fencing to prevent disturbance from vehicles and pedestrians. Nests and chicks were monitored at least two to three times per week until all chicks fledged. Nests were identified from a distance by counting incubating adults.
Average least tern productivity on USFWS monitored sites from 1995 to 2008 was 0.34 chicks fledged per pair. Least Tern productivity has been variable from year to year ranging from a 0.63 in 1995 and 2001 to a 0.03 in 1996 and a 0.04 in 2000. Productivity for 2008 was 0.34 overall, with the highest productivity (0.9) documented at Trustom Pond NWR.
Phragmites removal at Ninigret NWR and at Cards Pond of Trustom Pond NWR
Treatment of approximately 20 acres of salt marsh habitat at Ninigret NWR was initiated in fall of 2006 to reduce the density of common reed (Phragmites australis) in the marsh. We documented a dramatic decline in the number of live stems per plot between the pre-treatment monitoring (pre) and the initial herbicide and mulch treatments at Cards Pond and Ninigret NWR, see chart below.
Number of Common reed live stems recorded in 60 plots prior to and after herbicide and mulch treatments at Ninigret NWR and Cards Pond (adjacent to Trustom Pond NWR).
American Black Duck Monitoring:
Winter waterfowl surveys are conducted in salt marsh habitats at Ninigret, Trustom Pond, Sachuest Point and the John H Chafee refuges. Although surveys have been conducted for over 10 years at three of the refuges, JHC surveys were first conducted in 2004. Surveys are initiated in November of each year and continue bi-weekly through February.
The average number of American Black Ducks (ABDU) observed per survey from 1998 through 2008 on four NWRs in RI.
Response of the Resources of Concern
- Christmas bird counts were conducted in grassland habitats at Sachuest Point, Trustom Pond and Ninigret by volunteer birders. All of the sites continue to provide valuable habitat for a wide diversity of species throughout the winter months, including short-eared owl, northern harrier, and eastern meadowlark.
- Woodcock surveys have been conducted intermittently over the last 15 years at Ninigret and Trustom. There are two survey routes at Trustom for a total of 12 points and one route at Ninigret consisting of 9 points. We have data for 1993-1995, 2006 and 2008 (see chart below).
Average number of American woodcock detected per point during spring calling surveys at Trustom Pond and Ninigret NWRs during the last five years.
- On July 12, 2008 we participated in the annual butterfly count organized by the National Audubon Society. We surveyed the Ninigret salt pond and headquarters units and volunteers surveyed Trustom Pond fields and along Moonstone Beach Rd and beach. Notable finds include the variegated fritillary at Ninigret and Baltimore checkerspots at Sachuest.
- During August 2008 we participated in a Regional effort to inventory bee species on National Wildlife Refuges in Region 5. Following the standardized protocols, we placed four transects in open areas at both Trustom and Ninigret for a total of 8 transects. Each transect consisted of 15 total bowls, with five each of three colors. The bowls are left out for 24 hours and then collected and shipped to Patuxent for identification.
- During the Trustom Pond NWR Shorebirds Surveys, which include beach face and pond shore habitats, the most frequently detected species include the piping plover (PIPL), spotted sandpiper (SPSA), semipalmated sandpiper (SESA) and least sandpiper (LESA). The highest number of species occurred on October 1 with a total of 204 individuals. Ninety five of those were sanderlings and 61 were semipalmated plovers.
Trustom Pond Ecology Project:
Resources of Concern:
- A complete inventory and mapping effort was initiated this year (2008) through CCS funding and a contract with the Rhode Island Natural History Survey (RINHS). The focus was on mapping the distribution and abundance of Submerged Aquatic Vegetation (SAV) in Trustom Pond and comparing that to data from 1985 and 1995.
- The RINHS inventoried the shoreline as part of the Trustom Pond Ecology project and discovered four new plant species, three of which are species of concern in Rhode Island. The species of concern include mudwort (Limosella australis), seabeach sandwort (Honckenya peploides) and monk bishop’s weed (Ptilimnium capillaceum). The fourth species discovered is sea purslane (Sesuvium portulacastrum), which is considered rare, but does not appear to have listing status.
- In conjunction with the New England Wild Flower Society, the shoreline at Trustom was also surveyed for rare plants historically documented there including whorled milkwort (polygala verticillata var. ambigua) and sea pink (Sabatia stellaris). Sabatia has not been observed since 2000 when one small, blooming plant was observed. The polygala has also not been observed in over ten years. The grass pink (Calopogon tuberosa) that was re-discovered in 2006 following the burn in the peninsula field has not been documented since that time.
On Trustom Pond we initiated fish sampling in 2007 to compare the fish community to what was documented during 1985. Minnow traps were deployed along the pond shore at 36 randomly selected locations, with 9 traps stationary for 9 consecutive days and 27 additional traps locations sampled for three days. Traps were run during September and again in October following the breaching of the pond in 2007 and during September in 2008. A total of 15 species were detected overall, with the most common species being pumpkinseed during all trap days. Mummichog and four spine stickleback were only detected in 2007, while white perch (Morone americana) of this age class were only detected in 2008 (Figure 19).
Figure 19. Total number of fish captured, by species, during shoreline minnow trapping at Trustom Pond NWR 2007-2008.
In addition to the minnow trapping we also collaborated with the University of Rhode Island vertebrate biology class to conduct seining along the shoreline in 2007 and 2008. Additional species detected during these surveys include Atlantic silverside (Menidia menidia), sheepshead minnow (Cyprinodon variegatus), rainwater killifish (Lucania parva) and Northern pipefish (Sygnathus fuscus). Additionally, during mid-pond minnow trapping this year we detected a total of 342 individuals of 10 species, including one sea lamprey (Petromyzon marinus). Although the species composition has changed since 1985, we detected more species during our sampling (15 vs. 12). Species detected in 1985 that were not detected in 2007-08 were Mullet (Mugil curema), and unidentified species of herring and flounder. Those detected in 2007-08 but not in 1985 include freshwater species like largemouth and smallmouth bass (Micropteris sp.), pumpkinseed and bluegill sunfish (Lepomis sp), 4 spine stickleback (Apeltes quadracus ) and rainwater killifish that had never been documented in the pond.
Also as part of the TP Ecology project, a brief survey for benthic invertebrates was conducted during the summer. The results of this survey are being incorporated into a summary report that we will receive from the RINHS.
- Secretive marsh bird surveys have been conducted at Trustom since 2006. A total of six points are surveyed 4 times between March 15 and June 15 each year. We detected least bittern, sora, Virginia rail, and king rail during 2006-08.
- Waterfowl surveys were completed a minimum of twice per month between November and February. Most common species included the Canada goose, mallard, gadwall, greater scaup, and mute swan. The maximum number of individuals occurred on January 15 with a total of 1766 waterfowl observed (Figure 20). The pond continues to support as many as 20 waterfowl species during the migration and wintering months (Figure 20).
Figure 20. Total numbers and species richness of waterfowl species detected at Trustom Pond NWR during winter 2007-08.
Mute Swan Control:
Mute swan egg addling was conducted in the spring, and a round up was completed during the summer this year. A total of 5 nests with 30 eggs were addled on May 2, 2008. Four of the nests were on Trustom and one was at Cards Pond. The Cards Pond nest had 9 eggs, and one of the Trustom nests had 8 eggs. On July 30 a total of 43 adult swans were removed from Trustom Pond, swabbed for Avian Influenza and euthanized. This was coordinated through the RI DEM with assistance from CT DEP staff.
FY 2009 Management Strategy Prescription
- Continue to work with partners to complete the installation of the water control structure at Mud Pond which will restore the hydrology of this pond to benefit Fowlers toad and other species. We currently have a design for the structure and money obligated for the installation. We are waiting for an easement with the Town of South Kingstown who owns the road, and then we will be able to proceed.
- Continue controlling MUSW nests and adults through coordination and cooperation with the RI DEM Division of Fish and Wildlife.
- Waterfowl surveys will continue, and we will initiate additional behavioral observations to identify any significant differences in time allocation between Trustom Pond, Mud Pond and Cards Pond. This will be evaluated as part of the Trustom Pond Ecology project.
- Continue to work with the RINHS to evaluate the ecology of TP and work with partners to develop a long term management strategy that will address invasive species and improving habitat for species of management concern.
- We will continue to work with the New England Wildflower Society in the monitoring of rare plant species at Trustom on a rotational schedule. This year we are surveying the following plant populations along Trustom’s shoreline: mudwort (Limosella australis), whorled milkwort (Polygala verticillata var. ambigua) and sea pink (Sabatia stellaris).
Habitat Management (general maintenance):
Trustom Pond NWR
Current area managed for grasslands consists of 142 acres that have been on a three year rotation during the past 5 years such that each field has now received at least one treatment during this time period. During 2008:
- Field 1 was scheduled for a prescribed burn (15 acres) to maintain dominance by warm season grasses and reduce the build up of thatch. The burn was accomplished on approximately 12 acres on April 30 between 8-11pm. The west and center portions of the field burned well (12 acres), and the eastern portion was mowed the following week (3 acres).
- Fields 10 (goose field) and 13 were mowed (22 acres total) and the Meyers easement that was co-operatively planted in WSG was mowed in the fall (25 acres).
Rare plant population monitoring and management:
Trustom Pond NWR
- We introduced a population of sandplain gerardia (Agalinis acuta) in the western portion of field one on November 28, 2007. We monitored this population in September 2008 and counted a total of 102 plants. Many of the plants were already senescing, so we suspect the population was larger and we missed the optimum window for conducting the count. None the less, the introduction of seed was successful. The plot is comprised of mostly little bluestem, with goldenrod and Indian grass also present in the site. During the burn this area of the field was avoided and received only a mow treatment.
- In conjunction with the New England Wild Flower Society (NEWFS) the refuge was surveyed in the summer for hyssop-leaved hedge nettle (Stachys hyssopifolia, State Threatened). We counted approximately 500 Stachys plants in a 40m2 area located in the northern portion of field one. This area has been roped off and the population seems to be increasing.
- We continue to work closely with the NEWFS, and this year attended the NE Plant Conservation Planning group meeting, to monitor rare plant populations on the refuge on a rotational basis and input the findings into the online database maintained by NEWFS.
- A complete survey of the Trustom pond shore was conducted during the summer as part of the TP Ecology project. Several state listed plants were identified and mapped.
Invasive Plant Management
Trustom Pond NWR:
- Black swallowwort was hand pulled for two weeks before it could set seed, then cut as it began to go to seed, and when checked late in the season had leafed out again, so an herbicide was applied to the re-growth (2% Garlon). The largest patch was in the center of Field 1, although it was also detected along the farm field loop in the SW and NE.
- The area that was hydro-axed during January 2007, was treated with herbicide (stumps of invasives only) during that winter and then during the growing season of 2007 a foliar spray was applied (non-native invasive only) by contractors (Vegetation Control Services - VCS). During FY08, VCS returned to cut and treat vines, applying 3.25 gallons of mix on Dec. 5 and Feb. 28. The area is full of grasses and wildflowers, but has not had as much regeneration of native shrubs as I had hoped. We did not have the staff necessary to follow up with any treatments in the summer of 2008, although there are still some invasive species in the site. It will be important that the site is monitored annually and it remains a priority to prevent invasion of this site until it has filled in with native shrubs.