Washington College

In 1999 the Chester River Field Research Center (CRFRC) was established to address the myriad issues involved with the establishment of ecological conservation practices and wildlife habitat restoration on land adjacent to commercial agriculture.

At that time, little scientific information was available about the ability of USDA conservation programs such as CRP and CREP to improve water quality or their value as wildlife habitat. We were interested in the interface between intensive modern commercial agriculture and an effort to restore and conserve wildlife habitat and surrounding waterways.

The owner had for many years supported experiments in ecologically friendly agriculture and enthusiastically supported the vision of melding the aforementioned goals on land directly adjacent to the commercial row crop farming part of Chino Farms. The aim was to test if modern farming methods would make it hard to successfully reestablish wildlife habitat next to areas that were exposed to agricultural chemicals and practices. Also, would the newly established habitat harbor insects or other organisms that would be detrimental to the farmer’s crops?

Initially, CRFRC had four goals:

• Build a first-rate field research station that facilitates long- and short-term, basic, academic field investigations in ecology and conservation biology,
• Test through rigorous landscape-scale experiments for the restoration and management of wildlife habitats, especially for endangered grassland species of plants, birds, and insects (butterflies), on lands that have been heavily impacted,
• Formulate protocols for land managers in federal and state governmental agencies, conservation NGOs, and interested private land-owners, and
• Erect a training platform for environmental education, including hands-on programs for school children K-12, undergraduate and graduate students, senior citizens, community leaders, and people interested in the natural sciences.

In 2001, 99% of Chino’s property was protected into perpetuity when 2000 acres were placed under Conservation Easements and 3000 acres were consigned to Rural Legacy with the State of Maryland. Another milestone was the designation of the entire property as an Important Bird Area (IBA) by Maryland-DC Audubon in November of 2006. IBAs are recognized as being essential habitat for birds of concern.

The landscape-scale CRFRC experiment in native grassland restoration of recently retired croplands began in 1999. Special priority was given to the restoration of the mid-Atlantic coastal grasslands that once dominated the eastern Atlantic seaboard in pre-colonial times but are now a virtually extinct habitat. After two centuries of tobacco cultivation, intensive grazing on exotic pasture grasses, extensive peach and cherry orchards, and forty years of row-crop rotation in corn, wheat, barley, and soybeans since WWII, 228 acres of relatively unproductive sandy, acid soils were placed under 15-year, renewable contracts with the Conservation Reserve Program (CRP) of the US Department of Agriculture and Conservation Reserve Enhancement Program (CREP) with the State of Maryland. Twelve replicated fields of 23+ acres (see map below) were planted in eight species of native warm-season grasses and two cold-season grasses in five seed-mixture treatments in April 1999.

Management protocols (herbicide, mowing, and fire) were designed so that several structures of grasslands (short, tall, mixed) might be maintained. We monitored the establishment and maturation of the grasslands, and measured the rates of colonization of new plant species (i.e. increases in the species diversity), changes in the relative abundances by percent cover, and rates of vegetative growth and reproductive performance of the principal prairie grasses. The matched colors on the map below depict the replicate experimental CRFRC fields.

Colonization of the restored grasslands by obligate grassland birds started within one month of planting - Horned Larks, Killdeer, and Grasshopper Sparrows appeared in April 1999 and immediately established territories, engaged in courtship, and nested successfully. Other rare grassland birds, including Vesper Sparrow, Northern Bobwhite, and Dickcissel also colonized the Grasslands within the first two years, albeit in smaller numbers. Dickcissels have returned (as adults and young from previous years, thereby establishing new site fidelity records for the species in Maryland) every year. In 2004 and 2005 Sedge Wrens appeared and established late summer territories. These results encourage the adage that "Give them the habitat, and they will come!"

Because of the Grasshopper Sparrows (GRSP) abundance, we directed our ornithological research effort toward them, to use them as bio-indicators of the differences, if any, in the value of the alternative prairie types we installed and managed. Our mist-netting techniques proved satisfactory - we have banded 865 adult and 1898 hatch-year (HY) GRSP on the CRFRC Grasslands in ten years, and another 200 in other nearby habitats. All adults have been captured (often multiple times each breeding season), and color-banded for easy field identification and observation. The breeding population is 70-80 pairs each summer (see 2008 territory map below); an additional 10-20 males are caught each year that do not set up territories. We infer that males have higher annual survival than do females, generating these excess males. In contrast to reports of birds in the Mid-West our territorial male GRSPs exhibit remarkable site fidelity, predictably returning to the same acreage as held previous years. Our oldest male (oldest known GRSP on record in North America) was at least 8 years 10 months old in 2008 and has returned faithfully to the same territorial site for eight years! Management (e.g. prescribed fires every three years) and other changes in vegetation do provoke small shifts in the location of territories.

Our breeding adult and HY GRSP have returned to the CRFRC Grasslands at exceptionally high rates. Population structure seems to have stabilized since 2002 with over 45% of the adults returning to the grasslands from previous years. We have confirmed a minimum average (since 2000) of 57% of adult males (a high of 81% in 2003), 32% of adult females, and 11% (a high of 18% in 2004) of marked HYs returning to the grasslands each year. The actual number of returning GRSPs is doubtless much higher than our records show - many of the unbanded new breeders are probably our hatch-years (HYs) that were not caught the previous years. We estimate we catch about half of the annual production of the 360-400 nestlings from an estimated 120 successful nests on the grasslands each summer. In addition, we have seen several banded (USGS only) males on neighboring properties that we are confident are our HYs that have returned to the region but dispersed from the grasslands.