of the diet
Most peregrines feed almost exclusively on birds, and in many parts of the
world pigeons and doves are their favourite prey. However, peregrines
actually hunt a wide variety of birds. At the Toronto and Etobicoke nests,
17 species of prey have been identified to date, including such surprises
as American woodcock, Baltimore oriole, and eastern meadowlark. This list
pales in comparison though to the 47 species which Reginaís peregrines
have dined on over the past decade.
In wild settings, the peregrineís diet is
even more diverse. A six-year study in southern Scotland recorded more
than 3500 prey of 74 species. Nearly half of the individuals were rock
doves (i.e. pigeons), and overall the 15 most common species comprised 91%
of all prey. However, the range of prey was remarkable - birds as small as
the 6-gram goldcrest were taken, as well as male black grouse weighing
almost 1.2 kg! An even wider variety of species have been documented as
prey in California, where the list of birds hunted by peregrines now
exceeds 160 species, from as small as the yellow warbler and red-breasted
nuthatch to quite large birds such as western grebe, pelagic cormorant,
and black-crowned night heron.
The classic hunting method of the peregrine
is the high speed stoop in which it kills prey by striking it in mid-air.
Clearly this technique is not always suitable. With large prey such as a
goose or pheasant, a peregrine may grab hold and ride the larger bird to
the ground. This sometimes involves the two birds tumbling through the air
together in seemingly reckless fashion. In coastal areas, peregrines have
been seen chasing land birds offshore to tire them out, and on occasion
even plucking them from the surface if they drop into the water.
just for fledglings
For a bird the size of a peregrine, insects donít make much of a meal.
However, fledglings are often observed testing their hunting skills on
large insects such as dragonflies and butterflies; perfect practice for
the skills needed to catch aerobatic birds.
at climatic extremes
In temperate regions, peregrines kill the
occasional vole, squirrel, or rabbit, but mammals rarely exceed 1% of
their prey. The situation is quite different in the arctic, where lemmings
and ground squirrels are hunted regularly and may account for as much as
half of the diet Interestingly, at least some tropical populations rely
heavily on mammals too. In Fiji, a study of the peregrines nesting within
the rain forest fed predominantly on flying fox fruit bats. In North
America, juvenile peregrines have been seen hunting migrating bats on
Fish, amphibians, and
reptiles: a balanced diet?
Though peregrines arenít adapted for
fishing, the occasional individual has tried it all the same. Reports
exist in the literature of a brown trout in a Scottish peregrine nest, and
a salmonid fish being delivered to an Idaho eyrie by an adult. Some
observers have been fortunate enough to see peregrines capturing fish from
rivers, or in one case even from the sea off Tasmania! Surprisingly, the
occasional amphibian or reptile graces the peregrineís menu too. A study
in Spain found one lizard and an unidentifiable frog among prey remains,
and in Fiji a large gecko was discovered at a nest. Thus, while we may
think of peregrines being primarily bird-hunters, the reality is that they
are opportunists who can adapt their hunting techniques according to the
prey which is available.
(supplemented by observations from CPF records)
Barnes & Garwood.
1995. Peregrine falcon takes a fish in Idaho. Journal of Raptor Research
Bradley & Oliphant. 1991. The diet of peregrine falcons in
Rankin Inlet, NWT: an unusually high proportion of mammalian prey. Condor
Byre. 1990. A group of young peregrine falcons prey on migrating
bats. Wilson Bulletin 102: 728-730.
George. 1979. Snow goose taken by peregrine falcon. Raptor Research
Heredia et al. 1988. Status, ecology, and conservation of the
peregrine falcon in Spain. In: Cade et al (eds): Peregrine falcon
populations: their management and recovery, pp. 219-226. Boise, Idaho: The
Horne & Short. 1989. Peregrine falcon takes black-bellied
plover from sea off Kenya. Journal of Raptor Research 23: 181-182.
Mearns. 1983. The diet of the peregrine in south Scotland during
the breeding season. Bird Study 30: 81-90.
Parker. 1978. Peregrine quartering ground like harrier. British
Birds 71: 37.
Santa Cruz Predatory Bird Research Group. 2001. Peregrine prey
Triffo. 2000. The hunting behavior and prey selection of urbanized
peregrine falcons. http://falcon.unibase.com/triffo/preylst6.htm.
Weir. 1979. Brown trout among food remains in a peregrineís nest.
Bird Study 26: 200.
Wendt et al. 1991. Juvenile urban-hacked peregrine falcons hunt at
night. Journal of Raptor Research 25: 94-95.
White et al. 1988. A study of peregrines in the Fiji Islands, South
Pacific Ocean. In: Cade et al (eds): Peregrine falcon populations: their
management and recovery, pp. 275-287. Boise, Idaho: The Peregrine Fund.