The scent of research

I have utilized many of my senses during my research of Ferruginous Hawks: vision to identify the hawks as they appear from tiny pinpoints in the sky or perch cryptically on dirt mounds, sound to identify incoming adults as they scream their piteous cries as we approach their nests for monitoring, touch when grasping the hawk legs with enough power to restrain, but not enough to crush fragile bones (I also often experienced touch when the hawks touched me with their talons that sunk deep into the flesh of my hands).

During my first day banding chicks, I was immediately impressed by the smell of the Ferruginous Hawks and their nest. And I cannot say that I was smitten. It was putrid, with equal parts decay, ripe feces and an underlying oiliness. “That’s the smell of rotting ground squirrel guts mixed with excrement” my advisor informed me. I mentally retched.

My mantra during thatMelynda_1 first day Melynda_2was breathe through my mouth and let my fascination with the species over ride my protesting senses. Over the course of my field work, the Ferruginous Hawk aroma changed, or at least my perception of it did. As I worked with the nestlings (banding them and marking their downy heads and legs with color) and then the fledglings (when the chicks are as big as adults, with a few bristles of down sticking up through contour feathers, giving the impression of gawky teenagers with bad bedhead), I noticed I started appreciating the scent of these large prairie hawks. Their scent changed to a musky odour that was clean, earthy and sharp. I started to take pleasure in the redolent

Unwittingly, I became expert at detecting this scent, and once when opening a technicians field truck, I exclaimed in surprise “There’s been a Ferruginous Hawk in here!” The field tech assured me that she wasn’t hiding baby Ferruginous Hawks, but had retrieved a chick that had been accidentally force fledged (when a nestling decides to bail from the nest before it can fly ade  ptly). She had Melynda_3returned the chick to the nest and the gloves that she had been wearing were in the truck. I inhaled deeply.

Our sense of smell is a powerful evoker of memories and conjurer of emotions.   To me, the thought of Ferruginous Hawk scent will always be linked with expansive prairies, endless driving of questionable range roads in relentless search of radio-telemetered hawks, and the elation of watching young Ferruginous Hawks, who have survived the risky period post-fledging period, finding their coordination and soaring strongly, yet effortlessly, on thermals as they prepare to begin their first migration south.

Written by Melynda Johnson

Wild Weather

Photo: Janet Ng.

Photo: Janet Ng.

Spring snow storms, tornado warnings, hail storms, and thunder storms are all part of field work. While we can take cover in our houses and trucks, Ferruginous Hawks are left out in the storm to fend for themselves.

It can get pretty rough out there. In fact, Ferruginous Hawk nests can actually blow right out of the tree, usually killing the eggs or young. Our nest monitoring program has found that 20% of nest failures are due to nests blow-outs and climate change scientists are worried that this will happen more often when storms become more frequent and more severe.

 

World’s Biggest Ferruginous Hawk Nest

FEHA nest sculpture in Leader, SK.  Photo: Janet Ng

FEHA nest sculpture in Leader, SK. Photo: Janet Ng

Some of our field work takes up to far flung places in Alberta and Saskatchewan.  Leader, Saskatchewan has several claims-to-fame including nine Larger Than Life sculptures that are scattered through town.

Our favourite, of course, is the 15 foot Ferruginous Hawk nest that resides on main street.

FYI, they frown upon climbing into the nest.

Burrowing Owl family in Leader, SK.  Photo: Janet Ng

Burrowing Owl family in Leader, SK. Photo: Janet Ng

Finding Old Friends

A returning banded male Ferruginous Hawk with his mate.  Photo: Janet Ng.

A returning banded male Ferruginous Hawk with his mate. Photo: Janet Ng.

Each bird we handle, we add two small pieces of jewellery. Both are thin metal bands that wrap loosely around their lower leg. One is a plain silver-coloured leg band that has a unique serial number engraved on it. The second leg band is coloured with a unique combination of large letters and numbers that can be seen from a distance or through a spotting scope. The National Banding Office keeps track of the band numbers and colour combos.

I encountered this pair of Ferruginous Hawks during our spring reoccupancy surveys. They were hanging out on a distribution line, in a territory that was occupied two years ago. Looking through a spotting scope, it looked like the male (the smaller hawk on the left) was wearing a leg band, but he was too far to read the band through my spotting scope. Instead, I took a photo using a telephoto lens and then zoomed in to read the band. Black 7 over S!

Resighting a band on a live bird is a rare event. Imagine writing your name on a ball and throwing it back into a huge ball pit at a play park. Now go find it. You could spend a very long time looking for it and it’s possible that you never see it again.

But finding a banded bird again can provide valuable information. If you banded it as a youngster, you will have age, where it was born, and the where it lives now. Sometimes birds are found during migration, providing important information about their migratory timing and pathway.

Male Black 7 over S was banded as an adult in 2012. He was captured in order to attach a short term satellite transmitter that was designed to fall off naturally. We collected data from the transmitter for several weeks during the breeding season, until the battery quit as planned.

A different male Ferruginous Hawk, but a nice looking bird wearing one of our satellite transmitters.  Photo: Janet Ng.

A different male Ferruginous Hawk, but a nice looking bird wearing one of our satellite transmitters (see the dark spot on his back). Photo: Janet Ng.

Resighting this male is interesting in several ways. 1) He has returned to his original home range with a potential mate. We’ll keep an eye on him this summer to see if he nests. 2) He is no longer wearing his backpack transmitter, which makes us feel good that he doesn’t have to carry his transmitter anymore.

Our project has banded nestlings for specific research objectives too.   Each year, we wait to see if any bird can be re-sighted by our group, other biologists, and citizen scientists.

Here is a young female Ferruginous Hawk sporting her new bands.On the left leg (her right leg) is the field-readable colour band and the silver band with serial number is on the right leg. Photo: Janet Ng.

Here is a young female Ferruginous Hawk sporting her new bands.On the left leg (her right leg) is the field-readable colour band and the silver band with serial number is on the right leg. Photo: Janet Ng.

Keep checking back for posts about our satellite tracking, juvenile life after leaving the nest, and banding.

Birds of a Different Colour: Ferruginous Hawk colour morphs on the Canadian Prairies

The Raptor Ecology and Conservation Team (REACT) is in the midst of the “trapping stage” of our 2014 field season. We trap adult male Ferruginous Hawks and attach solar powered GPS Satellite Transmitters which broadcast, to us via satellite, minute-by-minute hawk locations.

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An adult male modelling his new transmitter. Photo Credit: Jesse Watson.

As of June 19th, Jesse Watson and his crew members have capturedand attached transmitters to 6 adult males in the interest of quantifying home range sizes, priority foraging and perching locations, and migratory pathways. Telemetry data will also be used to define critical habitat under the watch of Species at Risk Biologist, Dr. Troy Wellicome.

These data are enormously powerful and we are very fortunate to have a dataset with such a wealth of information from which we can derive a wide variety of complex and fascinating research questions.

Our trapping efforts have also yielded another interesting outcome. We have captured 2 Ferruginous Hawk “Dark Morphs”, a plumage color morph that deviates strongly from the typical Ferruginous Hawk morph (see above). Rather than the characteristic “ferruginous” rusty coloration and white belly, these birds exhibit dark plumages with minimal rusty reds mixed in (see below). The Dark Morph is said to make up only ~ 5 – 10 % of the population, so we consider ourselves lucky see these birds up close and personal.bdc2 bdc3

 

Contrasting dark morph (left) and light morph (right) Ferruginous Hawk captures in June 2014. Photo Credits to Adam Moltzahn.

Counting Beaks and Butts

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Baby Ferruginous Hawks look up at our Tree Peeper camera. Photo: Janet Ng.

Our Raptor Ecology and Conservation Team (REACT) is running North America’s largest Ferruginous Hawk nest monitoring program.  In order to study Ferruginous Hawk ecology and potential cumulative effects, we check on hawk nests once a week to compare nest success across the Canadian Prairies.

We use an extendable painter’s pole with a camera mounted on the top to peer into nests.  We call them our “Tree Peepers”, trademark pending.  This method is effective and fast, thereby reducing disturbance to the nest. Check out the video below to see how’s it done.

 

We check on nests until the young fledge (i.e. naturally leave the nest) or until the nest is done.  If the nest didn’t fledge any young, we record reasons for failure.  Was it predated?  What kind of animal was the predator?  If the nest was successful, then we record the number of young fledged, when they left the nest, and other similar data.

All the data goes into our huge database (cue computer noises) and is readied for our analyses.

Nice view, guys!  Photo: Janet Ng

Nice view, guys! Photo: Janet Ng

What Happened to “The Early Bird Gets the Worm?”

Our Ferruginous Hawk crew had been installing tiny digital cameras near hawk nests to record how much food is delivered by the parents, hawk behaviour at the nest, and even prowling predators.

Not every minute is action though, as this sleepy FEHA is obviously not a morning bird.

 

Click on the photo to download a video of a sleeping Ferruginous Hawk.

Guess its a good thing FEHAs are raptors, not worm-eaters!

 

Forget the Robin, returning Ferruginous Hawks are the true harbingers of spring

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Each spring, Ferruginous Hawks return to the Canadian Prairies from their wintering grounds and our research team is ready to greet them. These provincially endangered and federally threatened Hawks return from the United States and Mexico in mid-March, when they form pairs and build their nests.

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“Everything went South for Ferruginous Hawks” Southward migration paths for 11 Ferruginous Hawks monitored using GPS satellite telemetry in 2012 and 2013.

Ferruginous Hawks generally return to the same territory and nest as the previous year, but this isn’t always the case. Some nests are used for 10+ years and others are abandoned after only one year. Understanding what influences their habitat selection between years could be crucial for their habitat conservation.

Our team heads out first thing in the spring to tour southern Alberta and Saskatchewan. We check on historical Ferruginous Hawk nests and seeing who has returned home. Encountering a spring snow storm is pretty typical for our early spring field work, but it’s nothing that North America’s largest Hawk can’t handle.

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A FEHA nest in a spring snow storm. That nest looks pretty cozy to me.

Sometimes Hawks choose to nest in a new spot because they had a lousy run the previous year. Our study has found that Hawks that had a successful nest the previous year are more likely to come back and use the same nest. Hawks that didn’t fledge any young were more likely to change nests the next year. This means that, like many bird species, Ferruginous Hawks will hedge their bets. If they did well last year, they’ll try the same thing again. Last year was terrible? They’ll try something new and hope for the best.P1P4

A female Ferruginous Hawk sits in the nest prepared for another breeding season. You get pretty good at identifying Hawks from just their foreheads, which are sometimes the only thing visible through a spotting scope 300 m away.

Other factors can also influence re-occupancy of nest. Winter storms can knock nests out of trees and other species will even steal a Ferruginous Hawk’s old nest. We’ve encountered Great Horned Owls, Red-tailed Hawks, Swainson’s Hawks, Common Ravens, and Canada Geese in old Hawk nests.

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A female Great-horned owl incubates her eggs in a nest which was occupied by Ferruginous Hawks in previous years.

Our team’s research will be ongoing throughout the summer of 2014 with the ultimate goal of improving Ferruginous Hawk conservation and management strategies. But, in the meantime, we are happy to already confirm nearly 200 “Ferrug” nesting attempts this breeding season!

Stay tuned for more updates,

Cameron Nordell, Jesse Watson, and Janet Ng

Our research group is the Raptor Ecology and Conservation Team (REACT) in Dr. Erin Bayne’s lab, partnered with Dr. Troy Wellicome with Environment Canada.