Some nest and winter here, but are they part of our wildlife community?
By Joe Kosack, Wildlife Conservation Education Specialist, Pennsylvania Game Commission
PYMATUNING, Pa., Oct. 25, 2011 /PRNewswire-USNewswire/ -- What in Sam Hill are sandhill cranes doing in Pennsylvania?
They don't have much history here; their status was more of a just-passing-through or accidental visitor than anything else. Heck, they don't even have relatives in Pennsylvania. But their growing presence here ensures that those folks who refer to most wading birds as "cranes" will start to be right some of the time!
"Sandhill cranes, until relatively recently, weren't part of the state's breeding bird community," explained Dan Brauning, Pennsylvania Game Commission Wildlife Diversity Division chief. "In fact, it's sort of amazing they're anywhere in North America today given the bird's troubled past."
A majority of the sandhill crane's global population historically has nested throughout Canada. East of the Mississippi River, they predominantly inhabited the Great Lakes in substantial numbers through the 1800s. But they encountered hard times when increased unregulated hunting pressure and habitat loss limited their productivity. By the start of World War II, it was believed there were only several thousand remaining in North America. Since then, heightened management attention and the bird's increasing and advantageous use of agricultural areas have helped the sandhill regain its standing in the United States. Today, it is the most abundant crane species in the world, and is expanding its range into Pennsylvania and other states.
In 1888, when B.H. Warren, who eventually became the Game Commission's first executive director, penned his Birds of Pennsylvania, he referred to the "green-legged, little brown and large white cranes," referring to the names people gave green herons, American egrets and, possibly, bitterns. There was no mention of sandhills.
George M. Sutton, who wrote his Birds of Pennsylvania in 1928, only mentioned the "crane" or "sandhill crane" as erroneous identifications of the great blue heron.
By the time W.E. Clyde Todd wrote the Birds of Western Pennsylvania in 1940, sandhill cranes were mentioned to have occurred in southwestern Pennsylvania during migration. But the bird was referred to as "very large wading bird," which it can be, but mostly is not.
Given the sandhill crane's previous identity problems and existence issues, and its historic nonresident status, it's no wonder most Pennsylvanians really don't know a lot about them. But the birds do have a mysterious side to them according to the International Crane Foundation. Headquartered in Baraboo, Wisconsin, the organization works toward a future where all crane species are secure and where people cooperate to protect and restore wild crane populations and their ecosystems.
"We've been following sandhill cranes for 20 years and we're still learning things," noted Matt Hayes, a Foundation sandhill crane researcher. In June, Hayes, accompanied by Andy Gossens, from the International Crane Foundation, and Hoa Nguyen, from the University of Wisconsin at Madison, came to Pennsylvania as part of a multistate research project to collect information on and genetic samples from the newest additions to Pennsylvania's limited, but established, sandhill nesting population.
Directed by Game Commission staff with assistance from local birders, Hayes focused mostly on possible nesting sites in northwestern counties and another site in Bradford County. Finding sandhill chicks – sometimes referred to as colts – in the lush, emergent vegetation of the lowlands in which they prefer to nest was equivalent to sifting through sand for a contact lens in sweltering, humid conditions while serving reluctantly as a lunch wagon for the insect world.
"In Pennsylvania, the Foundation's mission mirrors the work of the Game Commission, which is why our organizations immediately recognized the need to partner," Brauning said. "Matt Hayes found plenty of interest among and assistance from local birders and agency field personnel who helped him and his team to nests that were always hard to find. Cooperation was vital to the success of this ambitious fieldwork."
"Nests are so hard to find," Hayes explained, "even with a helicopter and plenty of help. The birds paint themselves with mud and when it dries they blend in so well. We try to time our searches to take chicks when they're five to six weeks old, which is when they're easier to handle and can be banded."
The Game Commission and the Foundation are interested in learning more about what sandhill cranes are doing in Pennsylvania and charting their range expansion. Their remarkable resurgence follows a horrific population tailspin they seemed unlikely to escape.
"The Great Lakes population went through a historic bottleneck in the 1930s," Hayes explained. "We don't know what their previous numbers were, but we do know they were reduced to about 300, including 25 to 30 breeding pairs in and around Wisconsin, Minnesota and Michigan. Today, they are 50,000 cranes strong in the Great Lakes; 650,000 globally."
Sandhills currently can be found from Siberia to Cuba. It is believed the migratory Great Lakes sandhill crane population, which nests from Minnesota south and east to Ohio, is spurring the expansion into Pennsylvania, and as far east as New York, Massachusetts and Maine. So these birds, which have inhabited the continent longer than any other extant bird species, now seem to find the Mid-Atlantic States and New England attractive.
But why? Why is the bird's nesting frontier Pennsylvania and not also Virginia or Maryland? Is it latitude? Climate? Habitat? Surely, they have areas that resemble Pennsylvania's countryside mix of wetlands, farmlands and fallow fields south of the Mason-Dixon Line. Hayes is quick to point out that cranes can be wanderers and bewildering.
"That's why we're interested in their dispersal and movements; how this growing population is expanded its geographic range," Hayes said. "Sorting it out will help us try to better understand the overall population ecology of the sandhill crane. We suspect the main part of the Pennsylvania population is probably from the Great Lakes, but we want to try and understand more about it."
Brauning noted that sandhill cranes seemed to have been sizing up Pennsylvania as potential nesting territory since the early 1990s.
"Then, in 1993, a pair was observed in Lawrence County doing courtship behavior," Brauning said. "The birds suddenly disappeared for a few months in the summer. The next time they were seen, they had a juvenile crane. We were quite surprised!"
Since that 1993 breeding confirmation, sandhills are believed to have been recurring nesters in the state's northwestern and northeastern counties.
"A number of sandhill cranes have been observed over the past 10 years, summering in the northwest – Butler to Crawford counties – and in Bradford and Sullivan counties," Brauning explained. "At times, young were observed, but the state's first confirmed sandhill crane nest was found only in 2009. A nest that was uncovered this spring by Land Management Group Supervisor Jerry Bish and Northwest Region Land Management Supervisor Jim Donatelli in the Pymatuning region yielded two, two-day-old chicks during this fieldwork."
Sandhills nest on the ground; nest materials are usually comprised of whatever vegetation is dominant in the wetland area they chose. The female lays two eggs normally and they hatch in about a month. The young will fledge, or begin to fly, in about 70 days.
"The chicks have a pretty long period of vulnerability where they're susceptible to predation," Hayes said. "But once the chicks get to six to seven weeks of age, they tend to do a much better job of defending themselves, especially when their parents are around."
Haynes noted that family ties among cranes are pretty strong, especially when it comes to encounters with predators.
"We were watching a flock of 20 birds hanging out in a field in August and all of a sudden their heads went up," Hayes explained. "They all started looking around and then circled up like musk oxen do and all the chicks went in the middle. The adults were on the outside with their bills pointing out. A coyote suddenly appeared and ran through the field. After it passed, they broke apart and returned to foraging."
The sandhill crane, despite its limited population in Pennsylvania, is not a state endangered or threatened species.
"Because sandhills are expanding their range into Pennsylvania, and were not a historic nesting bird here, at this time it seems inappropriate to list them," Brauning said. "That listing process is designed to protect species in decline. We're glad sandhills have become a member of the state's breeding bird community, but their overall population gains make it clear they're not a species of special conservation need."
Sandhills have established themselves firmly in Pennsylvania. Their known nesting presence is growing and they've been wintering in increasing numbers in western counties – Butler, Crawford, Mercer and Lawrence – for almost 20 years. Some also are wintering in eastern Pennsylvania, particularly Lebanon and Lancaster counties. Sandhills seem to be finding the tranquility and that modicum of privacy they – both breeders and non-breeders – prefer in several areas of the state.
"Sandhill cranes are a very watchable wildlife resource, "Brauning said. "There are seasonal chances to see them at the Pymatuning and Middle Creek wildlife management areas, but the best place to watch sandhills in the state is at Pennsy Swamp on State Game Land 284 in Mercer County."
If you observe what appear to be nesting sandhill cranes, or adult cranes in summer with juveniles, the Game Commission would like to hear from you. Send an email titled Sandhill Crane Observation to firstname.lastname@example.org. Include details on the potential nesting or sighting location and contact information.
Adult sandhill cranes are 12-15 pounds in size and have a distinct red skin patch on their forehead and crown. Males are slightly larger. In flight, its wingspan is about seven feet. The mostly grayish bird stands at about the same height as a great blue heron (roughly 40 inches) and may be seen foraging for everything from worms and insects to mice and waste grains in agricultural settings. The sandhill's piercing call also is a dead giveaway to its presence and takes a backseat only to its dancing grace when assessing the bird's charms after encounters with it.
Sandhill cranes, like all wildlife, are dependent on habitat and a peaceful coexistence with humans to ensure their future. But for now, they have plenty of elbow room in Pennsylvania and their limited numbers aren't a threat to anyone. That's why they're here; they fit in. And, they're one fine addition!
NOTE: High-definition, broadcast-quality b-roll video to accompany this news release can be downloaded from Youtube.com (http://www.youtube.com/watch?v=2-MNuktVx_A). Also, photographs to accompany this news release are available from the Game Commission's website (www.pgc.state.pa.us) by clicking on "Resources," then choosing "News Releases" and then selecting "Release #121-11."
Note to Editors: If you would like to receive Game Commission news releases via e-mail, please send a note with your name, address, telephone number and the name of the organization you represent to: PGCNews@pa.gov
SOURCE Pennsylvania Game Commission