IBO's Curlew Crew Blog
|
Rose-colored stories from the field are often emphasized; for curlews this includes freshly hatched chicks, incredible migrations, and general goofiness like males hurling dirt clods at their competition. But like any wild animal, curlews face many day-to-day perils and don’t always come out on top. While we hope to write about plenty of rosy moments, sharing the gritty stories in tandem with happy ones presents a more unfiltered view of curlew ecology. It’s a view we don’t want to shy away from. |
A Tough Season for Frank and Bethine
Frank and Bethine's nest, with the original nest cup and crushed egg on the right, and the "auxillary" nest cup on the left.
Normally, male and female curlews divide duties to maintain round-the-clock incubation for about 28 days. Night shift goes to the male, and daytime is left to the female. Breaks from the nest are rare, with quick incubation switches as the only consistent interruptions. There is variation, but that’s the typical curlew nesting schedule.
Here was Bethine though, off the nest at midday, and agitated. I was in the area doing a nest visit the first time I saw her do this. Our typical vantage points for monitoring nests are hundreds of meters away from the actual nest; we always try to minimize our presence. The failed nest I checked while she called sits about 250 meters from hers, so chalked it up to me being too close. Looking through the scope later, I found her back on the nest and thought maybe all was well. When she did the same thing the next day, my curiosity wouldn’t let it pass a second time. At the nest, only 3 of originally 4 eggs remained. One smashed egg lay flattened site up in the nest cup and the other two rested about a foot over, outside of the cup. Based on the curlew-sized circle of pressed down cheatgrass centered on those two eggs, the pair hadn’t given up on incubating, despite evident drama. The crushed egg presented a risk of luring predators. It also contained valuable DNA information, which would likely disappear quickly during the week remaining before hatch date in this predator-laden environment. After some thought and a quick phone call, I ended up collecting it for DNA sampling.
Heather and I returned again on the projected hatch date. As if the scene couldn’t get any more confusing, we were met with new drama and clues. One egg was still in the nest cup. A long crack ran along the underside of the egg. Ripe and sulfuric-smelling, the crack must have been from a while before. Bethine flapped around and called nearby, but hadn’t been on the nest. While I walked back to the car to get some Ziploc bags, Heather watched a weary-looking Frank fly in. He wasn’t defensive like Bethine, and when he landed, limped heavily before perching on a ground squirrel mound. Frank stayed puffed up (often a sign of stress) and dozed off and on the rest of the time we were at the nest. We searched the area around the nest and Heather found the saddest thing yet: a newly hatched, but dead curlew chick less than 10 meters from the nest. A predator had torn off one of its feet, bruised the same leg, and probably squeezed it a bit, too.
A mystery. But, from what we could piece together a cow maybe clipped a couple of the eggs while walking over the nest. Cattle graze the area, and would be one of the few animals not too interested in eating a clutch of curlew eggs. We guessed the only uncracked egg hatched, but the new chick may have been grabbed by a raptor before making it more than a few meters from the nest. Frank could have received his injuries then, fighting off the raptor, which then dropped the chick.
While Frank and Bethine experienced a particularly rough breeding season, their failed nesting attempt is more the norm than an unusual occurrence. Of the 27 nests we found at the ACEC, only 6 successfully hatched at least one chick. What follows for a chick that does hatch? Flightlessness on open prairies until long adult feathers grow in, a migration hundreds of miles long, and surviving long enough to reach maturity and breed. What we learn about the complete annual cycle of curlews will help us delve into and mitigate issues where we can.
Here was Bethine though, off the nest at midday, and agitated. I was in the area doing a nest visit the first time I saw her do this. Our typical vantage points for monitoring nests are hundreds of meters away from the actual nest; we always try to minimize our presence. The failed nest I checked while she called sits about 250 meters from hers, so chalked it up to me being too close. Looking through the scope later, I found her back on the nest and thought maybe all was well. When she did the same thing the next day, my curiosity wouldn’t let it pass a second time. At the nest, only 3 of originally 4 eggs remained. One smashed egg lay flattened site up in the nest cup and the other two rested about a foot over, outside of the cup. Based on the curlew-sized circle of pressed down cheatgrass centered on those two eggs, the pair hadn’t given up on incubating, despite evident drama. The crushed egg presented a risk of luring predators. It also contained valuable DNA information, which would likely disappear quickly during the week remaining before hatch date in this predator-laden environment. After some thought and a quick phone call, I ended up collecting it for DNA sampling.
Heather and I returned again on the projected hatch date. As if the scene couldn’t get any more confusing, we were met with new drama and clues. One egg was still in the nest cup. A long crack ran along the underside of the egg. Ripe and sulfuric-smelling, the crack must have been from a while before. Bethine flapped around and called nearby, but hadn’t been on the nest. While I walked back to the car to get some Ziploc bags, Heather watched a weary-looking Frank fly in. He wasn’t defensive like Bethine, and when he landed, limped heavily before perching on a ground squirrel mound. Frank stayed puffed up (often a sign of stress) and dozed off and on the rest of the time we were at the nest. We searched the area around the nest and Heather found the saddest thing yet: a newly hatched, but dead curlew chick less than 10 meters from the nest. A predator had torn off one of its feet, bruised the same leg, and probably squeezed it a bit, too.
A mystery. But, from what we could piece together a cow maybe clipped a couple of the eggs while walking over the nest. Cattle graze the area, and would be one of the few animals not too interested in eating a clutch of curlew eggs. We guessed the only uncracked egg hatched, but the new chick may have been grabbed by a raptor before making it more than a few meters from the nest. Frank could have received his injuries then, fighting off the raptor, which then dropped the chick.
While Frank and Bethine experienced a particularly rough breeding season, their failed nesting attempt is more the norm than an unusual occurrence. Of the 27 nests we found at the ACEC, only 6 successfully hatched at least one chick. What follows for a chick that does hatch? Flightlessness on open prairies until long adult feathers grow in, a migration hundreds of miles long, and surviving long enough to reach maturity and breed. What we learn about the complete annual cycle of curlews will help us delve into and mitigate issues where we can.
Curlew in flight at the intersection of development and a breeding area. Photo by Stephanie Coates.
|
Curlews live a harsh reality, where nests often fail due to predators. The other eggs from this nest were cached nearby, suggesting a coyote or badger might return later to finish their meal. Photo by Stephanie Coates.
|
About Frank the Curlew
Frank is one of 15 satellite-tagged curlews from IBO's curlew tracking project. He was captured in late spring of 2014 near Boise, Idaho in the Long-billed Curlew Habitat Area of Critical Environmental Concern (ACEC). Since then, Frank traveled to his wintering grounds near the Salton Sea after breeding in 2014. In the spring of 2015 he returned to his previous territory, bred with the same female as the previous season, and after a tumultuous breeding season, again made the journey back to the Salton Sea where he will spend nearly 9 months until the next spring. Frank's mate, Bethine, is also equipped with a satellite transmitter backpack and was captured around the same time as Frank, allowing us to track them as a pair.
Frank and Bethine's namesakes are Frank and Bethine Church, key figures in Idaho for their contribution to the conservation of wild lands. Frank Church's efforts as a senator and wilderness advocate led to the creation of the second largest wilderness area in the lower 48 states, the River of No Return Wilderness. In 1984, four years after its designation as a wilderness area, Frank Church's name was appended to the official title. Jagged mountain ranges, forested slopes, and the Salmon River cutting through deep canyons, still define the landscape of the Frank Church- River of No Return Wilderness today. Though Frank the Curlew prefers grasslands to rugged mountains, preserving habitat is a key component of wildlife conservation.
Frank and Bethine's namesakes are Frank and Bethine Church, key figures in Idaho for their contribution to the conservation of wild lands. Frank Church's efforts as a senator and wilderness advocate led to the creation of the second largest wilderness area in the lower 48 states, the River of No Return Wilderness. In 1984, four years after its designation as a wilderness area, Frank Church's name was appended to the official title. Jagged mountain ranges, forested slopes, and the Salmon River cutting through deep canyons, still define the landscape of the Frank Church- River of No Return Wilderness today. Though Frank the Curlew prefers grasslands to rugged mountains, preserving habitat is a key component of wildlife conservation.
A Long-billed Curlew near Boise, ID, nearly ready for transmitter attachment. We place an alpha flag (green with white letters) on the upper leg, and a USGS-issued aluminum band on the lower leg. Photo by Stephanie Coates.
|
Frank spent much of the winter near the borders of Mexico, California, and Arizona (see above map). His mate from the 2014 season, Bethine, spent the winter farther north in California's Central Valley.
Male curlews typically arrive back at the breeding grounds before females in order to establish a territory. They have "high site fidelity" which means they tend to return to the same place, year after year. Females curlews can be a little more fickle, often switching to new territories and mates based on the success or failure of their previous nest. If her eggs were gobbled up by a coyote, she probably won't take her chances there again. |
Frank getting equipped with a satellite transmitter during the 2014 breeding season. Photo by Liz Urban.
|
One year later, Frank and Bethine are paired again. Looking to collect some genetic samples as well as check the fit and possible wear from the transmitter, we re-captured both (several days apart). May 2015. Photo by Stephanie Coates.
|
