Black rails are experiencing dramatic population declines along the Atlantic Coast.
But luckily, the coastal plain of South Carolina has emerged as one of their last strongholds. In their 2018 Species Status Assessment, the U.S. Fish & Wildlife Service (USFWS) concluded that without help, the subspecies found in our state is likely to face extinction in as few as 50 years. SCDNR staff recognized the urgency of the situation. But before they could help black rails in South Carolina, they needed to figure out what help the birds needed.
Historically, the Eastern black rail was reported as far north as Massachusetts and as far west as New Mexico. But in some areas of the country, their disappearance initially went undetected because the species is so difficult to survey. Black rails are among the smallest rails in the world. Binoculars are useless when looking for black rails. They so rarely emerge from the dense grasses where they spend most of their lives scurrying along the ground.
In 2013, when SCDNR biologist Christy Hand learned the species needed immediate attention, she says she was shocked by how little was known about a bird that lived so close by.
Using specialized surveying techniques that are commonly used to study the species, Hand and other biologists determined where in South Carolina black rails were living — but unlike the rest of the region, South Carolina’s biologists did not stop there. Because they lacked the information they needed to help the species or the tools to gather that information, SCDNR staff experimented with new tools. Dr. Elizabeth Znidersic, a colleague in Australia, had used motion-activated cameras to study two Australian rail species. After she shared this technique with SCDNR, Hand successfully adapted it to the study of black rails. She found it to be even more valuable than she had anticipated.
Prior to Hand’s research, black rail chicks had never been seen in South Carolina — and had never been photographed in the wild. The timing of nesting, chick rearing, and even how long it takes for chicks to grow into adults was unknown. To help the rails survive and reproduce, biologists needed this basic information – and Hand and her crew were able to gather it using the cameras.
“We’ve learned that black rails have a long breeding season in South Carolina – spanning from April into September.”
When conditions are favorable throughout the season, pairs can successfully raise more than one brood of chicks,” Hand said. This discovery is some of the most hopeful news from her work. It means black rails have the capacity to recover if we provide optimal conditions.
There was another key aspect of black rail biology that Hand felt deserved more attention: molting. Like ducks, adult black rails suddenly lose all the flight feathers on their wings and tails at the end of the breeding season. The timing and duration of this molt was a mystery prior to SCDNR’s work on black rails. Adult rails lose their flight feathers after they finish raising their final brood of chicks. For about three weeks, they are unable to fly as their new feathers are growing. Hand’s work determined the timing of flightless molt ranges from mid-August through mid-October — which coincides with the peak of hurricane season!
While black rails are caring for their eggs and chicks, and while they are unable to fly due to molt, they are particularly vulnerable to sudden flooding caused by high tides, storms or wetland management.
Even adult black rails only stand about four inches tall and must climb into vegetation or swim when water rises over a couple of inches. Due to their tiny size, black rails live in the very highest areas of salt marshes and wet meadows. As tidal marsh habitat is lost to increasingly frequent flooding, black rails are becoming more reliant on managed impoundments. As Hand learns more about their habitat requirements and management needs, SCDNR Wildlife Management Area biologists and technicians are paying extra attention to impounded wetlands where black rails nest. Impoundments with the relatively dry grassy expanses that black rails require are rare — but very valuable to the rails when managed compatibly.
In collaboration with the USFWS Coastal Program, SCDNR is improving impounded wetland infrastructure and removing invasive trees from a few of the wetlands where black rails were found during surveys. The impoundment enhancements will allow SCDNR to keep water levels ideal for breeding. The invasive tree removal will provide grassy habitat at the edges of wetlands. This provides the rails with a safe place to go when flooding occurs in their usual habitat.
“We still have a lot to learn about this understudied species,” Christy Hand said. “But using motion-activated cameras has provided a window into the relationship between water level management and reproductive success.”
SCDNR staff are already applying what Hand has learned to help protect black rails on state-managed lands. To ensure the populations black rails, biologists and land managers must find innovative solutions to meet conservation needs.
Please note: All photographs and videos of black rails were collected using motion-activated cameras. This is in part with SCDNR’s research project (SCDNR Permit BB-20-06), for conservation and protection of the species. Every precaution is taken to minimize disturbance to these birds and their fragile habitat during research.
Article by E. Weeks, http://sccoastalresources.com/home/2020/9/28/behind-ghost-bird-key-discoveries-about-the-elusive-black-rail?utm_content=&utm_medium=email&utm_name=&utm_source=govdelivery&utm_term=.