guest blog

Out in the Field

By Katie Harrington, Research Associate and Former Conservation Science Trainee
Hawk Mountain Sanctuary

I have just returned to Hawk Mountain from a two-month field effort conducting behavioral and dietary studies of Striated Caracaras, or Johnny Rooks, as the locals call them, in the Falkland Islands. Set off from the coast of South America in the South Atlantic, in a back eddy of the circumpolar current, the Falklands embody the sense of expedition, expanse, and natural beauty that would make any graduate student –especially me– weak in the knees.

Being my third visit to Saunders Island, human population of 4, I had a sense of what to expect: gales and squalls, immense starry skies, long summer days, and thousands of birds. I stayed in a cottage at the Farm Settlement and shared the company of my hosts, the Pole-Evans family, at their farmhouse in the late evenings. During the days, I would figuratively saddle up on an ATV, part the sheep, brake for hens, and set off on the undulating dirt track toward the Neck 10 miles to the northwest, where I’d spend the day with roughly 100, mostly juvenile, Johnny Rooks.

It’s an amazing study population that Dr. Keith Bildstein began banding in 2006. Over 80 percent of the individuals I observed I could call by the name on their leg band, Z26, K27, G22, etc., which allowed me not only to observe population-level patterns, but also to learn more about different individuals’ behavior over space and time, that is, who hangs out where and with whom, for how long, and doing what.

Rooks raking shoulder to shoulder in the kelp wrack that has washed up on the beach.

Rooks raking shoulder to shoulder in the kelp wrack that has washed up on the beach.

For my graduate work at Moss Landing Marine Labs in Monterey Bay, California, I am investigating the role the Rooks play in energy flow in their marine environment. It’s well known that Johnny Rooks associate with seabird colonies, but it’s less understood the extent to which they depend on invertebrates, both terrestrial and marine, as a nutritional resource. You might not think a raptor, formerly persecuted for slaying sheep and frequently labeled a penguin-killer, would spend hours each day silently and determinedly raking for larvae in accumulated kelp wrack. I certainly didn’t, but they do! It’s this behavior I set out to learn more about.

Layered in merino wool, I’d sit for hours, recording three different layers of resolution, from macro to micro: (1) total time an individual Rook spent foraging within the kelp wrack, (2) proportion of time spent actively digging and ingesting invertebrates versus a catalogue of other behaviors within a 4-min period, and (3) ingestion rates within a 30-sec period. Combined, these layers will help me better understand kelp raking as a foraging strategy, and the implications of changing social or climatic conditions.

X36 Yellow hours after receiving a tail mounted accelerometer. If all goes according to plan, we'll find out exactly how he spent the next twenty-four hours after we download the data!

X36 Yellow hours after receiving a tail mounted accelerometer. If all goes according to plan, we'll find out exactly how he spent the next twenty-four hours after we download the data!

A second goal of mine was to deploy and retrieve accelerometers that I had built before leaving San Francisco.  Having learned to wire, solder, and program the archival Arduino microloggers, I had my fingers crossed that I wouldn’t lose them forever. Rooks are wily and persistent, especially when it comes to disarming and destroying miniature gadgets, so I wasn’t entirely sure my plan would work. Luckily, by using two layers of heat shrink and Tesa tape and then tail mounting the units, it did! Keith warned me going into this, saying that it’s easy to trap Rooks, but it’s harder to retrap the one that's wearing your unit. Although, with a single snare and cubed mutton, we fortunately “lassoed” all six of our “accelerometered”  birds! What a rodeo! I’ll now be able to plug these data into visualization software, and by syncing the movement records with behavioral observations I conducted while the birds wore the units, I’ll be able to extract activity signatures and quantify total time spent doing each activity for a twenty-four hour period. I’m deeply indebted to banded Rooks  X36, P25, V26, Z26, M26 and K27. Thank you young Rooks!

For many of my days, I’d sit still and observe, doing my best to blend in with the environment. Frequently, when I would put down my binoculars I’d find a Gentoo Penguin peering closely at me, within arm’s reach, or a pair of King Penguins slowly waddling past me toward the water. Or I’d be closely watching one Rook raking while another, often a recently fledged one or a juvenile, would sidle up beside me to stare at me, head turning upside down for a better look, or to play with my thermos. On many days there would be a Sea Lion hunting and preying upon Gentoos 100m offshore, grabbing and slapping the penguin’s body back and forth on the water. Southern Giant Petrels would get the first go at the remaining carcass, but once it washed ashore it became a hierarchical battle between them, the Rooks, and the local Turkey Vultures. Southern Crested Caracaras steered clear with Petrels around. Not to say they didn’t hold weight at the Neck though, as whenever they flew over, the gulls, oystercatchers and Rooks all would flush in alarm.

Recently fledged K28 after kickboxing a ball of dried basket kelp. 

Recently fledged K28 after kickboxing a ball of dried basket kelp. 

While the Rooks spent most of their days at the Neck foraging or digesting, the four recently fledged Rooks that arrived midsummer introduced me to another side of the species. I’d watch and try not to laugh as they ran toward inanimate, inedible objects and kickboxed them, grabbing on and stumbling over themselves while they held on their “toys.” They’d lie there on their side, partially flapping, partially kicking, and doing what I could only call playing with the objects. Energetic and clumsy, they seemed to be learning to navigate their world. I could certainly relate to their seeming enthusiasm.

Working with the Rooks has been an incredible opportunity to contribute information on a little-studied species, engage with the amazing South Atlantic ecosystem, and build relationships with local residents who have been so generous in supporting our work. Keith and I will return to the islands in July to present our findings at a “Farmer’s Week” get-together in Stanley, the capital of the islands, before continuing to Saunders Island to rejoin the Rooks. Until then, I’m sure they’ll be raking away, running under fences, and continuing to perplex and delight, and, perhaps, frustrate all who encounter them.  

Annual Raptor Care & Wellness

By Susan Pello, VMD, MS
Small & Exotic Animal Veterinarian

Hawk Mountain Sanctuary currently has 4 education ambassadors. Each bird is carefully monitored and cared for by the education staff as well as trained volunteers at Hawk Mountain. Our avian education ambassadors are trained to work with the staff to educate the public, and they represent their wild counterparts as they travel near and far. However, every bird requires daily care and yearly examinations. I enjoy travelling out to Hawk Mountain every spring to see the birds. At times, the birds will travel out to me for any issues concerning to the raptor care staff.

So, how do wild raptors become education ambassadors? Due to injury, amputation, blindness or imprinting, raptors that come into a rehabilitation facility are determined to be unfit for release and in turn become captive raptors for education. The federal government mandates specific guidelines and criteria which must be met prior to releasing a bird of prey back into the wild.  In raptors 6 weeks or younger, we worry about imprinting on humans. If this occurs the animal becomes non-releasable. We see imprinting commonly in baby cranes, vultures and other avian species.

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A captive raptor requires yearly exams and wellness blood work just as our companion animals. Raptors are considered wild animals, even in captivity and their care is much different from that of a dog. Birds hide illness and therefore require a physical exam and blood work yearly.  The day to day care, includes monitoring their appetite, weight and activity. When a bird is transferred to a facility, an initial physical exam, x-rays and blood work are performed. During physical examination, I will evaluate the eyes, mouth, ears, listen to the heart and respiratory system and perform a full orthopedic examination. Feather and skin condition is also evaluated.

When housed in a captive setting, especially birds with orthopedic limitations or previous fractures, raptors are prone to feather damage and foot injuries. Together with the raptor care team, I will review options to help improve feather quality, foot care and cage enrichment. At Hawk Mountain Sanctuary, a physical examination is performed, blood is drawn and xrays are recommended. It is also recommended that all captive raptors be vaccinated for West Nile Virus (WNV).  The WNV vaccine is administered once a year prior to mosquito season. This is the only recommended vaccination.

At the time of intake, all of the birds are DNA sexed and this is because our female birds require higher levels of calcium and monitoring for egg laying behavior. The birds can produce an unfertilized egg, without a male present. Currently, all of the education birds at Hawk Mountain are female, except the newest member, a red-morph eastern screech owl.

The red-morph eastern screech owl was recently adopted by Hawk Mountain for education purposes. He has a right wing injury that limits his flight, therefore he has been determined unfit for release into the wild. He received his intake examination in January 2017.  The small owl was found to be dehydrated with multiple broken tail feathers and contracture to his right wing. Despite his severe right wing damage, he is still able to fly a little. During his examination we administered his WNV vaccination and took some blood to evaluate him for any illness.

During my visit, I also had the luxury of examining my favorite great-horned owl. GHOW is at least a 17 year old female who recently started laying eggs. She also has developed some abnormal wear to her beak and receives occasional coping (beak shaping).  

I look forward to my spring visit this year when I will have the opportunity to vaccinate and examine the entire flock of avian ambassadors at Hawk Mountain.