Image for An extraordinary Picture Essay: The nesting Peregrine Falcons ...

Female feeding a noisy miner to three fluffy chicks suggesting third hatched at night

Prepare to be amazed. These shots, taken in a remote Tasmanian location, document the hatching and early life of arguably the world’s fastest animal, The Peregrine Falcon ... They are simply an astonishing record of the nurturing and early life of this spectacular and handsome creature of The Wild ...

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Peregrine in flight at Table Cape, by Bert Quant

BACKGROUND

The peregrine falcon Falco peregrinus is famous for many reasons, including it being:

• arguably the world’s fastest animal
• spectacular (and handsome) appearance in flight and at rest
• one of the most widespread and successful birds being found naturally on all continents except Antarctica and all large islands except New Zealand.
• specially adapted for catching flying birds
• used by people for falconry
• heavily impacted by some pesticides (there have been consequent efforts most famously in the USA, to recover it from such
• heavily impacted by persecution because of its predation on game birds (in the northern hemisphere) and domestic pigeons (many countries including Australia, in particular Tasmania)
• one of the most observed, researched, photographed and written about wild birds.

Depending on whether you are a ‘splitter’ or ‘lumper’, 16 -25 races/subspecies of peregrines appear worldwide. Those breeding in very high latitudes of the northern Hemisphere (such as Alaska) tend to be large and migratory while those in low latitudes tend to be sedentary, sometimes sharing habitat with northern birds visiting on migration. Those of moderate latitudes, places such as most of Australia including Tasmania, the UK, The Falkland Islands (aka Las Malvinas) etc also tend to be sedentary. Australia has just one race/subspecies, F.p. macropus (meaning ‘big foot’) and it has been here for many thousands of years – carbon dating of mummified remains of long dead peregrines at an old nest site in Tasmania show it was used at least 19,600 years ago – the oldest known nest of a bird.

Peregrines catch prey with their feet and most prey is killed by breaking/crushing their neck with their very powerful beak. Relatively small prey is dealt with on the wing while large prey may be hit a very heavy glancing blow knocking it to the ground and is then dealt with there. Australian peregrines are of moderate size (in Tasmania, when breeding, adult females weigh about 900g and adult males about 550g – yes, females are larger, this reversed sexual dimorphism being usual in birds or prey). It is thought that their unusually large feet and powerful beak are adaptations for catching parrots over forest - prey that must be quickly dispatched because it can be dangerous and places the falcons cannot afford to drop their prey (nowadays the peregrines have adapted to more open habitat and somewhat different prey including introduced birds). Typical of a non-migratory peregrine, ours have very solid bodies and relatively short wings giving a high wing loading and potentially exceptionally high speeds. Peregrines from North America are typically larger (for taking large game birds) with relatively longer wings (for migration) but relatively smaller feet and beaks (their natural prey is not so dangerous).

Peregrines typically take what prey of suitable size is most available although individual specialisation certainly occurs. ‘Suitable size’ is generally from 10-50% of their own weight and ‘available’ is not necessarily abundance since peregrines cannot hunt in dense vegetation where some birds are very common (but rarely caught). In Tasmania, prey depends on where the peregrine lives and can range from seabirds such as prions, shearwaters and gulls on the coast to cuckoos, parrots, miners, wattlebirds etc in forest to a diet increasingly based on starlings, lapwings (plovers) and galahs in farmland. Domestic and feral pigeons are taken but availability varies immensely over time and place. Essentially, diet reflects local availability of suitable prey in that rare prey is usually rarely taken unless it is very vulnerable physically (ie it stands out from the crowd) or behaviourally (it does bizarrely dangerous things). Racing pigeons, escaped aviary birds and newly arrived ‘novel’ prey fit these criteria and already 3 rainbow lorikeets have been recorded as prey in Tasmania. Escaped budgies too, often don’t last long, the blue one I saw flying low across the Derwent, chirping loudly being a case in point. Members of pairs may hunt cooperatively.  The main defence of prey is combativeness (although suitably sized, cockatoos are dangerous prey), flocks and homogeneity of appearance and behaviour, familiarity with local landscapes, alertness, and experience (knowing when to hide or escape).

Just as ‘every shark is not a great white’, every raptor is not a wedge-tailed eagle nor peregrine falcon. Tasmania is a great place for peregrines but far from the best. Our nesting population recovered from ravages of organochlorine pesticides in the 1960s,  70s and into the 80s and persecution from the 1930s , through legal protection (of the falcons) in the early 1970s to now, with perhaps 120 breeding pairs which translates from a seasonal high of about 700 individuals to a seasonal low of about 600. Our population has been relatively stable for some years now. Most are clustered in river valleys and along suitable coastline and on inshore islands and where close (say less then 4km apart) pairs tend to be evenly distributed since they are highly territorial. Nests are fiercely defended even against people.

Although on mainland Australia some peregrines nest in old eagle nests or even hollow trees essentially the species nests on cliffs on ledges and in potholes. All confirmed nests in Tasmania have been on cliffs. A site sheltered from heavy rain or high chill-factors is preferred and just a scrape is made to lay eggs. Clutch size varies from 2-4. Eggs are layed every second day and incubation proper starts with completion of the clutch, lasting for about 32 days. Most eggs hatch and males fledge at about 40 days old if left to their own devices, and females about 43 days. After fledging, juveniles are dependent on their parents for 4-8 weeks, gradually dispersing. Females disperse further than males. Not all nests are used every year but those of the highest quality are permanently occupied. Post dependence mortality is naturally high (about 50% in the first year) but this decreases with experience gained. Males become mature at 3 years old and females at 2 and they can then expect to live for another 4-8 more years.

THE WI-FI NEST

The cliff pothole nest site that is the subject of this remote, wi-fi camera has a typical clutch of 3, just as typically completed on the 16th September and hatched 18-19th October. The adults are not leg ringed or otherwise marked - that phase of our research ended many years ago so all I can say is they are at least 2 years old for the female and 3 for the male. They seem unusually attentive, especially so the (smaller) male who tries to brood more often than usual, although already the chicks are getting too large for him. 

So far the male has been doing virtually all the hunting while she stands guard and prey has been nearly exclusively starlings with a few rosellas (both eastern and green), a noisy miner and a skylark, a typical mix for this nest in the past and this rural habitat. Once the chicks are about 3 weeks old they are large enough to defend themselves against nest raids by ravens and conserve heat so they can be left alone for longer. They also naturally demand more food and the female will start hunting then. Larger prey such as masked lapwings and galahs may consequently appear. Typically, food is provided every few hours of daylight – mostly it is fresh caught but sometimes it is leftovers or food cached nearby.

This educational project has been set up to avoid the necessity for approval from an Animal Ethics Committee by using a static, remote camera without manipulation of the birds. The very high fidelity, persistence and resilience peregrines show to low levels of disturbance is also a key asset of the project, taken advantage of through my extensive experience with this species and the generosity, expertise and experience of Simon Plowright of Natureworld.

The nest is on private property and permission for access is very limited. It is a nest well known to locals and has been the subject of past persecution so I judge no or very little increased security risk from this project. The species is wholly protected by law and I and others monitor the site. We also have other cameras secretly installed nearby to help us monitor security.

Although technical issues have prevented us putting this ‘episode’ directly onto the web, Tas Times is a means to offer the opportunity to see this exciting and informative imagery and I have made a live video feed available to my local state primary school.

OCTOBER 17:

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Adult female incubating

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Female trying to roll eggs during hatching

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Eggs and just-hatched wet chick after female left to take food from male

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Adult male incubation shift arrival

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Male tries to cover newly-hatched chick and eggshells plus two eggs while female eats

OCTOBER 18:

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Female snoozing with nibbled eggshell in front

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Female regards two fluffy chicks and egg indicating second hatched did so at night

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Male tries to brood chicks and egg

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He tries again

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Female looking under male trying to force changeover

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Male leaving

OCTOBER 19:

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Female scraping in nest material to rim

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Female feeding a noisy miner to three fluffy chicks suggesting third hatched at night

OCTOBER 20:

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Female settling to brood

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Female brooding

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Female feeding three chicks a starling

OCTOBER 21:

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Female preening

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Female scratching

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Male partially brooding

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Female, left-hand side, organising a feed for the chicks

OCTOBER 22:

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Female struggles to get comfortable brooding

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Female gives up

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Female more comfortable

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Well-fed chicks

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Late brood change with male taking an evening flight as the female prepares to take over

OCTOBER 23:

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Female brooding

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Male alights while female off feeding

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Female arrives with partially-eaten green rosella

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Female feeds rosella to chicks

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Female brings starling

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Female feeding starling to chicks

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Male, right-hand side, and female attending chicks

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Female brings a late feed to chicks

TT will regularly update readers with the latest of Nick Mooney’s remote images ...

• Leo Schofield, in Comments: These images are quite extraordinary. I have a grandson who’s a budding David Attenborough to whom I’ve just despatched them. He will be enthralled as I was.

• Don Knowler, in Comments: I hate to use the over-worked word, icon, but I can’t think of any other to describe the place of the majestic peregrine in the Tasmanian environment.