Osprey nest watchers photograph fierce defensive attack on heron

Osprey nest watchers photograph fierce defensive attack on heron

By Rex Graham

Four dedicated Michigan birders said the ecstasy of watching a pair of Ospreys on Aug. 1 turned into agony as they witnessed one of the raptor’s ferocious attacks on a Great Blue Heron.

Maxine Biwer, a wildlife rehabilitator at the Howell Conference and Nature Center in Howell, MI, later said a quick response by the birders, a local canoe rental employee, and an ambulance-like drive to the nature center unquestionably saved the life of the slashed, soaked and shocked heron.

“He was soaking wet with a three-inch gash on his neck and puncture wound in his beak,” said Biwer, a veterinarian. “He was in shock. It took a couple hours for him to stop shaking. He later starting standing up and after that day he started eating minnows.”

Osprey nest, BirdsNews,com

This hapless heron must not have known that the perch he landed on was the nest of a notoriously aggressive female Osprey. (Photo: Jane Purslow Tina Gartley, Lou Waldock, Walter Chavers)

The heron’s ill-fated flight intersected with efforts by volunteer birders and the Michigan Department of Natural Resources to reintroduce Ospreys into southern Michigan. Unfortunately for the heron that afternoon, it was flying toward a man-made Osprey nesting platform provided and installed by the Michigan Department of Natural Resources.

The four birders, who call themselves the Osprey Paparazzi, were watching the action around the nesting platform as the avian drama unfolded.

“The heron came from behind us. The female Osprey was already harassing it,” said Jane Purslow, one of the Osprey Paparazzi birders who lives in Milford, Mich. “We have all photographed fights and we all knew something was going to happen.”

The female Osprey is one of the most aggressive defenders of her nest ever seen by Purslow and her three birding friends, Tina Gartley, Lou Waldock and Walter Chavers. The female has raised three chicks per breeding season on that nesting platform every year since 2004. She has paired with three males during that time and lost only one chick.

Starting in 1998, the Michigan Department of Natural Resources (MDNR) established a goal of re-introducing 30 breeding pairs of Ospreys in southern Michigan by 2020. They moved a few male Ospreys from northern Michigan to the Kensington Metropark in Livingston and Oakland Counties. By 2013, there were 50 breeding pairs of Ospreys in the area.

The female Osprey Kensington Metropark is the favorite of the Osprey Paparazzi and Osprey biologists. “She has been a marvelous mother, and one reason is because she is extremely dedicated to raising her young,” said Barb Jensen, a coordinator at Osprey Watch of Southeast Michigan, a group that supports the Osprey Reintroduction Program run by the MDNR. Jensen fitted a satellite transmitter several weeks ago on one of the female Osprey’s three chicks, a male dubbed Independence. The transmitter, which was purchased with grant funds provided by American Tower Corporation, was attached to the male Osprey so Jensen and other researchers can track its movements.

The first two chicks fledged about July 28, and were located in a cove of the Huron River. However, the male outfitted with the satellite transmitter disappeared from the nest the following morning. Jensen and the Osprey Paparazzi birders were fearful that the fledgling may have died.

Osprey reintroduction in Michigan, BirdsNews.com

Barb Jensen, a coordinator at Osprey Watch of Southeast Michigan, has dedicated much of her professional and personal life to the highly successful reintroduction of Ospreys into southern Michigan. (Photo: Jane Purslow Tina Gartley, Lou Waldock, Walter Chavers)

“Nobody saw it all day on Wednesday [July 31] and on Thursday [Aug. 1] morning nobody saw it,” Jensen said. “I had watched the two siblings after they fledged to see where they went, so I decided to search in that area.”

Jensen, Julie Oakes, a MDNR  wildlife biologist, and Brian Washburn, a research biologist at the National Wildlife Research Center, U.S. Department of Agriculture, kayaked to the isolated cove where the two other Osprey fledglings had begun roosting and heard the familiar chirping of Ospreys.

“I looked up and Independence flew over,” Jensen said. “I could see the transmitter antenna between his wings. I called Jane Purslow and I said, ‘He’s fine,’ and I heard a roar of approval from the shoreline.”

Jensen expects the fledglings to drop by the nest for an occasional gift of fish from their parents, but the youngsters rapidly learn how to fend for themselves. The wayward heron must not have known that the perch he landed on was an Osprey nest. In full defensive mode, the super-protective Osprey swooped toward the intruder.

“The heron opened its beak in a defensive posture, but the Osprey flew past and grabbed it from the back of the head and pulled it off the nest and flipped it,” Purslow said. “After the heron fell into the water the Osprey continued coming at it. The soaked heron flapped its wings and got half way to shore and looked like it was a going down. That’s when we made a phone call.”

Kensington Metropark staff took the call and contacted Heavner Canoe & Kayak Rentals in Milford. The company’s Nick Rudofski used a vehicle to tow a canoe on a trailer to the site of the bird battle. He and Waldock paddled toward the exhausted bird.

By the time Rudofski and Waldock retrieved the heron and paddled to shore, Purslow had already called the Howell Conference and Nature Center. Biwer, the center’s wildlife rehabilitator, prepared for the incoming patient.

“We take in about 2,300 animals a year, and half are birds,” Biwer said “This heron’s wounds healed quite nicely.”

Linda Brandt, a Howell Conference and Nature Center volunteer, released the heron on Aug. 9 near Wildwing Lake at Kensington Metropark. It’s possible the rehabilitated heron will avoid Ospreys and their nests for a long time.

“We see heron encounters with Ospreys,” Jensen said. “However, this mother took it to another level.” Jensen said the Ospreys she watches vary in temperament from being aggressive toward Great Blue Herons, to accepting them.

Osprey attack of Great Blue Heron, birdsnews.com

This female Osprey is one of the most aggressive nest defenders seen by a Michigan group of Osprey nest watchers. (Photo: Jane Purslow Tina Gartley, Lou Waldock, Walter Chavers)

“Bald Eagles will try to steal fish from Ospreys, and some Ospreys will take fish from other Ospreys, so there is thievery going on, and the more you watch birds, the more you see individual behaviors.”

Osprey Paparazzi, BirdsNews.com

These four dedicated birders in the Milford, Mich.-area call themselves the Osprey Paparazzi. From left, Lou Waldock, Tina Gartley, Jane Purslow and Walter Chavers. The Osprey nest is in the background.

 

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