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Posts Tagged ‘hooded vulture’

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By Katie Harrington, Hawk Mountain Graduate Student and Former Conservation Science Trainee

10 May 2017

This March I watched three Johnny Rooks feeding in the beached kelp wrack adjacent to a falling tide, with an endless symphonic bray of gentoo penguins in the background. Early afternoon seemed to be the rooks’ final push, as it were, to fill their tanks before tucking in for a late afternoon nap.

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A fresh bird with a fresh band; welcome to the world K28 Yellow.

While the adult and two juveniles raked with resolve, another rook, band K28 Yellow, walked to within three feet of me. Unlike times before though, it wasn’t staring at me. K28 Yellow, whose plumage betrayed it’s youth–a fledgling, perhaps having only left the nest just six weeks prior– approached a piece of dried “basket kelp” tucked between driftwood and beach cabbage. Without hesitation, K28 “kick-boxed” the kelp and, clinging to the fibrous ball, fell and rolled onto its back. I watched, trying not to laugh, as it pecked at, clawed, and rolled around with the basket for five minutes, doing what I could only call playing.  The raptor, a close relative of the Peregrine and other falcons, reminded me of a puppy consumed with its chew toy.

While extensively studied in mammals, there are far fewer recognized examples of avian play, particularly in raptors. Among birds it is best documented in corvids (e.g. crows and ravens) and parrots.  Raptor examples include object manipulation by a captive-raised goshawk, an observation of a wild marsh hawk playing with its horned lark prey, and aerial acrobatics of bald and imperial eagles.

It’s worth pausing here in light of the genetic revelations of the past decade that place caracaras and falcons next to parrots in the tree of life, rather than alongside hawks and eagles. In fact, when reading about the kea, a parrot found only on New Zealand, you could almost replace their species name with “Johnny Rook” and have it read seamlessly. They, like rooks, are highly social, bold, curious, opportunistic foragers that feed on insects just as readily as seabirds and carcasses. And they play, extensively, with other keas and with inanimate objects. These qualities, along with their approachability, make both them and the Rooks the perfect candidates for studying play in the wild.

This occasion of watching a rook play wasn’t an anomaly. Over the two months I spent on Saunders Island this past austral summer (Feb-March), I watched multiple solitary and social play events across all ages of rooks. One time, another recently fledged bird and an adult played with a sheet of plastic stuck in the sand dunes, again rolling onto their backs as they kicked and pulled. For others, old carcasses, long picked clean became ceremonial tug-of war tools. Given the intensity of local fishing, there were also plenty of cast lines that washed ashore, frayed, half buried, just begging to be played with.

Are the birds learning about their environment, building social bonds, or honing  predatory or stress responses? At this point, we don’t know. Fortunately, our long-term banding project allows us to track this behavior in specific individuals, creating an unprecedented opportunity to understand the adaptive significance of this behavior in a raptor in the wild. And let’s be honest, what’s more endearing than watching a predator kick its talons up and play?

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By Keith L. Bildstein, Ph.D., Sarkis Acopian Director of Conservation Science
Hawk Mountain Sanctuary

12 December 2016

We typically characterize vultures as gluttonous creatures, obligate scavenging birds of prey that engage in rough-and tumble feeding frenzies at large ungulate and pachyderm carcasses in the company of dozens of other “all consuming” vultures, scarfing up enough meat to last for several days.  And indeed, vultures sometimes eat so much food that they remain grounded for an hour or more after feeding for partial digestion to take place, before they are light enough to take off.  Having watched these birds feed for many years, I can tell you that all of this is true.  But watching vultures at so-called “vulture restaurants,” where humans routinely provide food, sheds light on an aspect of vulture feeding that goes largely unrecognized by the general public.

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The vulture restaurant at the Hoedspruit Endangered Species Centre in northeastern South Africa after dinner is served. Note the Marabou Storks in the foreground and the ling-necked African White-backed Vultures in the background. Hoodies are nowhere to be seen in the initial scrum.

In fact, some vultures are “finicky” as well as “voracious,” feeders; especially at vulture restaurants where daily meals are typical.  The world’s first vulture restaurant, in the Drakensburg Mountains of South Africa opened in the 1960s to help supplement the diets of local Bearded Vultures.  Today, vultures restaurants (bird feeders for vultures, if you will) are used to provide “clean,” lead-free meat to recently released California Condors in the American West.  Many of the restaurants are associated with ecotourism, serving a useful purpose in bringing vultures and people together.  One such restaurant at the Hoedspruit Endangered Species Centre near Kruger National Park in northeastern South Africa has been feeding wild vultures and other scavenging birds for more than 30 years.  The restaurant works well at attracting handfuls of Pied Crows and Black Kites, dozens of Marabou Storks and Hooded Vultures, and hundreds of African White-backed Vultures, the latter two of which are now Critically Endangered.

Earlier this month, University of KwaZulu-Natal post-doctoral student and Hawk Mountain research associate, Dr. Lindy Thompson, and I spent four days at the Centre near Hoedspruit trying to catch Hooded Vultures.  During that time we learned a lot about the finicky feeding behavior of the birds.  Our goal was simple enough: catch as many as three of the Hooded Vultures visiting the restaurant, and fit them with satellite-tracking devices that would allow us to monitor the movement ecology of the species, including information on how dependent individuals were on vulture restaurants in the region versus how much time they spent in the nearby Kruger National Park feeding on native wildlife, and how they interacted with other species in the region.

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Dr. Lindy Thompson, releasing “Don King” after his capture in February. Note his downy top-knot and relatively thin bill.

We already had caught and fitted 10 Hooded Vultures with tracking devices in South Africa, and two of our previously tagged birds actually showed up at the restaurant during our four days of observation, even though neither has been tagged there.  One of the two, Don King, had been caught at a private nature reserve 45 miles north of the Hoedspruit restaurant in February of 2016.  Don looked healthy enough, although he had lost his downy top-knot that led to its name.  The second tagged bird, Mopane, had been caught in Kruger National Park about 60 miles northeast of the restaurant in August of 2014.   It, too, looked quite healthy.

The two marked birds were joined by about 30 unmarked individuals that visited the restaurant daily.  Unfortunately we were unable to capture any of them.  We did snare several of the far larger African White-backed Vultures that clearly dominated the smaller “hoodies” at the restaurant’s offerings.   Hooded Vultures, it turns out, are finicky feeders when feeding in the company of White-backed Vultures, pecking at and gleaning only tiny scraps of meat with their small, thin bills, after the meat had been torn apart by the larger white backs during feeding frenzies.  By the time the hoodies got close enough to our traps, the snares we had set already had been pulled closed by the white-backs, making capturing the former all-but-impossible.

Lindy Thompson and Andre Botha of the South African Endangered Wildlife Trust will try to capture the hoodies at other feeding sites that attract fewer white backs.   Older elephant carcasses work well for this purpose, as they often continue to be visited by the more fastidious hoodies for several days after larger vultures, hyenas, and jackals have stripped most of the flesh from carcass.

The finicky feeding behavior of hoodies is well known among those of us that study the birds.  It appears that hoodies have instituted their own specialized feeding niche, one that involves “cleaning up” after the larger and less finicky species.  Although this makes hoodies a bit more difficult to capture, it is somewhat endearing as well.  As I see it, a vulture that cleans up after other vultures can’t help but be appreciated.

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Ariel view of Dakar, Senegal, a city of 3.5 million people and no traffic lights

By Keith L. Bildstein, Ph.D., Sarkis Acopian Director of Conservation Science
Hawk Mountain Sanctuary

11 November 2016

I began my studies of the world Critically Endangered Hooded Vulture in The Gambia in September of 2013, when colleagues and I placed four tracking devices on individuals in the exurbs of Banjul, the capital of that country.  Almost immediately thereafter, I thought about investigating their populations in Senegal as well.  Senegal, the western most mainland country in Africa is a much larger nation that completely encircles The Gambia–except for the latter’s small Atlantic coastline– and is an ecological  transition zone between the humid tropics farther south, and the Saharan desert of Mauritania to the north.

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The country-side along our survey routes

This year’s meeting of the Pan African Ornithological Congress in Senegal’s capital, Dakar, gave me the perfect excuse to follow up on this.  After attending the Congress and the important Second Pan African Vulture Summit associated with it, my colleagues and I tried to capture several “hoodies” in hopes of placing satellite tracking devices on them.  We also conducted three roadside surveys of vultures to learn more about the distribution of Hoodies and other vultures in the country.

Two mornings of trapping attempts at the Dakar Zoo produced no captures, and our attention on Sunday, the 23rd of October turned to leaving Dakar and traveling north to the small city of Louga, where three of us, Drs. Lindy Thompson, Rien Van Wijk, and I, planned to meet with a group of other European and African vulture biologists who also planned to survey vultures populations.

All went quite smoothly until we reached the town of Thies, Senegal, where our low-cost rental car overheated, forcing us wait on the curb for 6 hours for a replacement, which arrived only after darkness fell.  Driving at night in Africa is never easy–livestock, pedestrians, aggressive drivers, and potholes, see to that–and it was past midnight when we reached Louga, long after our colleagues had gone to bed.

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A Hooded Vulture perched near a nesting of Ruppell’s Vultures

A breakfast meeting the next day resulted in a decision to head southwest to the village of Dars, and then southeast on to the city of Mbaké, slightly more than 200 kilometers away, while surveying vultures en route.  Our colleagues would survey other routes.  We saw 169 vultures along the way, including 17 hoodies, 47 Ruppell’s Vultures, 71 White-backed Vultures and 34 Gyps vultures that we could not identify to species.  The route took us through open habitats not unlike those we survey in South Africa, except for the fact that all of the ungulates we saw on the way were domestic livestock (i.e., sheep, goats and cattle), rather than wild antelopes and other native mammals.  We spent the night in a small, and somewhat questionable, hotel on the outskirts of Mbaké, where a small red light over our beds confirmed our suspicions concerning the facility’s hourly rates of stay.

The next day involved following a meandering survey route to the city of Kaolack, which our travel guide referred to as the “armpit of Senegal. ”  Unfortunately, Kaolack turned out to be aptly named.  Our approach to the city included skirting the edge of a primary sewage treatment facility, which quickly cleared our nasal passages of the dust they had accumulated over the course of the day.  Our hotel and the opposite side of town proved to be something of an oasis, even if the highlight of its view-shed was an enormous

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A Hooded Vulture perched at the gate to our hotel’s parking lot in Dakar, Senegal

mountain of salt excavated from the adjacent hypersaline estuary. The day’s route included good looks at 46 Hooded Vultures, together with lesser numbers of Ruppell’s, White-backed, and Lappet-faced Vultures, along with several impressive multi-thousand bird flocks of White Storks.  Our third and final survey route, which took us back to Dakar, produced an additional 69 Hooded Vultures, a number of which were sighted in Dakar itself, together with smaller numbers of African White-backed and Ruppell’s vultures.  Although we were not sure of what to expect, the numbers of hoodies, in particular, were more that I imagined, albeit much less than 10% the density of those we had seen on similar surveys in The Gambia in 2013 and 2015, in more moist wooded habitats, about a hundred kilometers farther south.

Although we collected our data in a traditional fashion using our odometer to indicate the locations of all birds we sighted, we later entered our counts into the newly developed African Raptor Databank (ARDB).  The brain child of my good friend Dr. Rob Davies, the ARDB aims to ascertain the conservation status of raptors and their habitats across Africa, and to help build the local expertise needed to monitor these species in the future and implement a sound strategy for their effective safeguarding.

The ARDB will be completed in two phases. The first involves building a database over a period of five years (2013 – 2018). The second involves distribution modelling of each species in relation to the availability of its habitat and production of a conservation atlas for African raptors, online and hard copy. The project which received initial support from Hawk Mountain Sanctuary, is managed by habitat INFO, and is currently co-funded by The Peregrine Fund.

Given our initial experiences in Senegal, I plan to return early next year to conduct additional road surveys, as well as trap and affix tracking devices to two or more hoodies.

Importantly participants at the Second Pan African Vulture Summit I attended agreed to foster additional roadside surveys of African Vultures, the majority of which, including Hooded Vultures, are globally threatened or endangered.  Hawk Mountain plans to help in this effort every way possible, so that we can better assess vulture abundances and distributions, and, in so doing, formulate practical and effective conservation action plans.

Stay tuned as we continue to do so.

For information on how you can help, contact me at bildstein@hawkmtn.org.

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Hawk Mountain collaborator Kerri Wolter holding a tagged nestling Hooded Vulture in Olifants River Private Game Reserve, October 2013

By Keith L. Bildstein, Ph.D., Sarkis Acopian Director of Conservation Science
and Lindy Thompson, Ph.D., Hawk Mountain Research Associate
Hawk Mountain Sanctuary

10 November 2016

Yes, I admit it. We name our satellite-tracked vultures.

Some of our colleagues disagree with this, arguing that naming one’s study animals “personalizes” them in ways that make our observations less scientific.  But primatologist Jane Goodall and Nobel Prize laureate Konrad Lorenz named their study animals, and I have never doubted the scientific rigor of their work.  Naming animals as individuals makes their individual behavior easier to remember.  With more than 75 vultures tracked by satellite so far, numbers or alpha-numeric codes simply do not work as well, as names help to separate and categorize the birds in question and keep the stories of their movements in mind.

“Homebody,” a South African Hooded Vulture, is a case in point.

As a nestling, Homebody was fitted with a GSM satellite tracking device by Walter Neser and Kerri Wolter at the Olifants River Private Game Reserve in northeastern South Africa just west of Kruger National Park on the 19th of October, 2013.  Unfortunately, the unit never worked, and we decided to try to re-trap and refit Homebody with a new unit in the summer of 2014.  Trapping a vulture once is relatively easy.  We have caught hundreds of them.  Trapping the same bird twice, however, is a different matter entirely.  In 2004 we caught and placed data loggers in the body cavities of six Turkey Vultures to record their heart rates and core body temperatures.  The following year the birds needed to be recaptured and their data loggers removed to retrieve the accumulated data.  It took then graduate student and now Dr. Jamie Mandel, hundreds of hours during much of the next spring and summer to recapture four of the birds.  The other two were never recaptured.

 

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Hawk Mountain trainee Nobuhle Mabhikwa holding the retagged Homebody in the Olifants River Private Game Reserve in June 2014

We had allotted a week of field time to recapture Homebody to replace its malfunctioning unit with a working one.  Three days unsuccessfully attempting to do so had us at wits end.  Hooded Vultures defer to larger African White-backed Vultures at carcasses, and Homebody, even though present at our trapping site, hardly ever got close to the carcass, let alone the snares that we had set around it.  But then something happened that one only dreams about.  We were late getting to our trap the fourth day of field work, and lo-and-behold Homebody and several other Hoodies were already at the site picking up small pieces of the bait that remained from the previous day.  Disappointed by their early arrival we drove our Land Rover toward the birds, flushing all of them into the air.  Miraculously, Homebody, after taking off to escape our approach, flew into a thorn bush and became entangled on one of the lower branches, which had slid between its body and the backpack harness we had used to attach the tracking device.  Within seconds we ran to the bush and hand-grabbed Homebody, disentangled it, and brought it back to base camp.  We then removed the malfunctioning unit and placed a new, fully functional unit on it.  Within 45 minutes of its miraculous recapture, we were celebrating our “lucky day” over a couple of beers.  A once-in-a-million event allowed us finally to satellite track the young vulture that had been tagged eight months earlier.

 

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Tracking device recovered from Homebody in October 2016

This alone makes for a great story.  But Homebody’s epic journey does not end there.  Last week–and more than two years later–we received an email from Colin Rowles, game warden at the Klaserie Private Nature Reserve.   Colin said a staff member on fence patrol had found Homebody dead at an impala carcass. When Colin went to collect the transmitter, he found that a Martial Eagle had consumed most of the Hooded Vulture.  Jackal tracks at the carcass lead him to believe that a jackal had killed Homebody.   We hope to place Homebody’s unit, which is still working, on another Hooded Vulture as early as this December.

 

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Homebody’s movements 2014-2016

Even though the story ended tragically for Homebody, we have placed similar units on other Hoodies, both in The Gambia and Ethiopia, as well as in South Africa.  Although several of these birds have died, most are still alive and transmitting important information.  The data we are now gathering will allow us to offer advice on how best to protect these birds, as well on the factors that most threaten them.  Costs associated in doing this are not inconsequential.  Homebody’s unit cost four thousand US dollars and download information from the unit cost us close to 600 dollars per year.  The information, however, is “priceless.”  Understanding the ecological neighborhoods of Critically Endangered Hooded Vultures is key to protecting them.

To learn more about our work with Hooded Vultures and other species of scavenging raptors, or want to support our field efforts financially, contact me at Bildstein@hawkmtn.org.

My next blog will describe our recent field work in Senegal, where Hooded Vultures remain very much in evidence.

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