Polihierax semitorquatus

Geographic Range

Polihierax semitorquatus , the African pygmy falcon, is native to two separate regions of Africa: northeastern Africa including Sudan, Somalia, Ethiopia, Uganda, and Tanzania; and southwestern Africa including Namibia, Botswana, Angola, and Cape Province. This species is generally non-migratory. Polihierax semitorquatas shares its geographic range with the range of social weavers, Philetairus socius , in southern Africa, and white-headed buffalo weavers, Dinemellia dinemelli , in northern Africa.

• Biogeographic Regions
• ethiopian ethiopian
  • native native

Habitat

African pygmy falcons inhabit dry, arid climates with sparse vegetation. These areas may receive as little as 100 mm/year of precipitation, or up to 600 mm/year (Brown, et. al, 1982). With the exception of a few non-breeding members, African pygmy falcons almost exclusively inhabit areas where social weavers ( Philetairus socius , in the SW portion of its range) or white-headed buffalo weavers ( Dinemellia dinemelli , in the NE portion of its range) reside.

• Habitat Regions
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• desert or dune desert or dune
• savanna or grassland savanna or grassland
• scrub forest scrub forest

Physical Description

African pygmy falcons have a white face, breast, and abdomen. Female members have darker, chestnut colored backs, where males have grey backs. White spots decorate the back of the neck and the tail feathers. Polihierax semitorquatas has brown eyes and light orange legs. The base of the beak is an orange color, and the beak itself is grey. When hatched, African pygmy falcons are white in color and their eyes are shut. The eyes will normally open in two or three days. Young have paler feet than their adult counterparts, with a reddish-brown back and neck. The breast, face, and abdomen of juveniles is white. Members of the species will mature in approximately one year.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• female more colorful

Reproduction

African pygmy falcons rely on the social weavers ( Philetairus socius ) in the northeast part of their range and white-headed buffalo weavers ( Dinemellia dinemelli ) in the southwestern part of their range for nesting. Occasionally northeastern birds will occupy the nests of white-browed sparrow weavers ( Plocepasser mahali ) and glossy starlings ( Lamprotornis nitens ). Approximately one-quarter of all weaver nests in these areas are occupied by African pygmy falcons. Thus, this falcon is one of a few species of birds that are "obligate nest pirates" (also see South American troupials, Icterus icterus ).

More is known of Polihierax semitorquatus breeding habits in the southern portion of their range, but birds in both areas engage in a relatively quiet display that includes bobbing of the head, wagging of the tail, and calling. The female will squat down and raise her tail feathers to indicate that she is prepared to mate. Polihierax semitorquatus is usually seasonally monogamous, but is occasionally polyandrous, and it is not uncommon for two or more males to attend the same nest. This behavior may be influenced by limited availability of suitable nesting sites.

• Mating System
• monogamous monogamous
• polyandrous polyandrous
• cooperative breeder cooperative breeder

Polihierax semitorquatus usually will breed once per year, but will sometimes produce two broods in a favorable year. Eggs are normally laid about three weeks after copulation. The female lays from two to four eggs which are incubated for 27 to 31 days. Females begin incubating with the first egg laid, so hatching is asynchronous. Since the young do not hatch at the same time, they may be different sizes. The young will leave their nests from 27 to 40 days after hatching. Polihierax semitorquatus is considered sexually mature at one year of age.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
• oviparous oviparous

At the beginning of the breeding season, two or more parents choose a nesting chamber and reside there together. After the eggs are laid, the parents share incubation, with the female incubating most of the time and the male incubating while the female feeds. The male will also bring the female food while she is incubating. After hatching the female will tend to the young and the male will hunt for the family. After 21 days, when the chicks have grown feathers, the female will resume hunting. The birds leave the nest at around 27 to 40 days, but may remain with the parents for up to two months, and sporadically return to the nest. Both parents are very aggressive near their nest and their young do not usually fall victim to predators.

• Parental Investment
• altricial altricial
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • male
    • female
  • protecting
    • male
    • female
• pre-weaning/fledging
  • provisioning
    • male
    • female
  • protecting
    • male
    • female
• pre-independence
  • provisioning
    • male
    • female
  • protecting
    • male
    • female
• post-independence association with parents

Lifespan/Longevity

Little is known concerning the lifespan of African pygmy falcons, though it is likely similar to the six to eight (with a maximum of about twenty) year lifespan of other diurnal birds of prey.

Behavior

African pygmy falcons are social, relying on one or more partners for breeding and raising young. They prefer sparsely vegetated areas with a few trees for perching. Open areas are preferred for hunting. They are sedentary animals and will remain in one locale for most or all of their lives. These falcons usually hunt during the morning and evening, when it is cooler, and seek shelter from the midday heat. African pygmy falcons occasionally attack smaller birds in flight, but prefer to hunt small terrestrial animals. In flight these falcons flap their wings rapidly, with a sporadic distinctive downward thrust.

• Key Behaviors
• arboreal arboreal
• flies
• diurnal diurnal
• motile motile
• sedentary sedentary
• social social

Home Range

Home range sizes of African pygmy falcons are not reported.

Communication and Perception

The main communication between members of this species are the songs sung during mating, which are used to attract potential mates. Some bodily communication is seen during the courtship ritual, as the female indicates her availability by crouching and raising her tail feathers. The movements made by the male during courtship can also be perceived as a form of communication. African pygmy falcons have a very keen sense of sight, common to most diurnal birds of prey.

African pygmy falcons rarely call outside of the mating season. There have been a few different songs observed, including a "thin, squeaky 'tsip-tsip';'kiki- kik ' (last syllable accented), or 'twee-twee-twip' used by [the male] calling [the female] from the nest; a sharp ringing 'ki-ki-ki-ki-ki-ki-ki-ki' by young in threat; in copulation, purring 'kirrrrr-kirrrrr-kirrrrr'; negging chicks 'seee-seee-seee'" (Brown, et al., 1982). The calls are usually high in pitch and soft.

• Communication Channels
• visual visual
• acoustic acoustic

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

African pygymy falcons are carnivorous, with a diet consisting of mostly insects and lizards. Smaller birds and certain rodents are also sometimes preyed on. Occasionally these falcons will prey on weavers ( Ploceidae ) or their hatchlings when inhabiting their nests. It is believed that insects alone are insufficient for the dietary needs of young pygmy falcons. Lizards, rodents, and birds are crucial for the survival of the young. The falcon catches its prey by swooping quickly from the branch of a tree.

• Primary Diet
• carnivore carnivore
  • eats terrestrial vertebrates
  • insectivore insectivore

• Animal Foods
• birds
• mammals
• reptiles
• insects

Predation

Polihierax semitorquatus is rarely preyed on, as it is a fairly powerful predator itself. Occasionally immature African pygmy falcons will be attacked in their nests, but the aggression of the parents during breeding season normally prevents this.

Ecosystem Roles

Polihierax semitorquatus , due to its use of weaver nests ( Ploceidae ), can be considered parasitic or symbiotic, depending on the location. In the southwestern portion of their range, African pygymy falcons may protect social weavers from predators such as snakes, while gaining a safe area to raise young. White-headed buffalo weavers, in the northeastern part of their range, are more powerful than African pygymy falcons and receive no benefits from their presence. African pygymy falcons can be considered parasitic to white-headed buffalo weavers and considered a "nest pirate". African pygymy falcons are major predators of insects and lizards and are a danger to smaller birds and rodents.

• Ecosystem Impact
• parasite parasite

Economic Importance for Humans: Positive

Polihierax semitorquatus rarely intersects with humans due to the harsh climate that it lives in. The only real advantages to humans are ornithological study and birdwatching.

• Positive Impacts
• research and education

Economic Importance for Humans: Negative

There are no adverse effects of Polihierax semitorquatus on humans.

Conservation Status

African pygmy falcons are common birds within their range, they are not considered threatened. Man made structures have increased the number of potential nesting sites for these animals. It is possible, however, that urbanization could someday threaten Polihierax semitorquatus with habitat loss.

Additional Links

Encyclopedia of Life

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Daniel Davieau (author), University of Maryland, Baltimore County, Kevin Omland (editor, instructor), University of Maryland, Baltimore County.

References

Baicich, P., C. O Harrison. 2005. Raptors in Captivity: Guidelines for Care and Management . Minnesota: NWRA publications.

Berger, A. 1956. The Appendicular Mycology of the Pygmy Falcon (Polihierax semitorquatus). American Midlan Naturalist , Vol.55 No.2: 326-333. Accessed April 05, 2008 at http://links.jstor.org/sici?sici=0003-0031%28195604%2955%3A2%3C326%3ATAMOTP%3E2.0.CO%3B2-N .

Brown, L., E. Urban, K. Newman. 1982. The Birds of Africa: Volume One . United States: Academic Press.

Fergeson-Lees, J., D. Christie. 2001. Raptors of the World . massachusetts: Houghton Mifflin. Accessed April 12, 2008 at http://books.google.com/books?id=hlIztc05HTQC&dq=raptors+of+the+world&pg=PP1&ots=6wnxbN1GDD&sig=jCH6cBlb866UDYyu6voJ9pOcLkw&hl=en&prev=http://www.google.com/search?hl=en&q=raptors+of+the+world&sa=X&oi=print&ct=title&cad=one-book-with-thumbnail#PPA681,M1 .

Kemp, A., A. Vidhidharm. 1998. Breeding of the White-rumped Pygmy Falcon. Wilson Bulletin , 110(1): 71-76. Accessed April 15, 2008 at http://elibrary.unm.edu/sora/Wilson/v110n01/p0071-p0076.pdf .

Kruger, O., R. Liversidge, J. Lindstrom. 2002. Statistical modelling of the population dynamics of a raptor community in a semi-desert environment. Journal of Animal Ecology , Vol.71: 603-613. Accessed April 05, 2008 at http://www.blackwell-synergy.com/doi/pdf/10.1046/j.1365-2656.2002.00626.x?cookieSet=1 .

Nicholls, M., R. Clarke. 1991. Biology and Conservation of Small Falcons . University of Kent: University of Kent press.

Sibley, C., B. Monroe Jr.. 1990. Distribution and Taxonomy of Birds of the World . New Haven, London: Yale University Press.

Spotiswoode, C., E. Herrmann, O. E Rasa, C. Sapsford. 2004. Co-operative breeding in the pygmy falcon Polihierax semitorquatas. Ostrich , 75/4: 322-324. Accessed April 05, 2008 at http://www.zoo.cam.ac.uk/zoostaff/bbe/Spottiswoode/Papers/Ostrich-Spottiswoode_et_al_2004.pdf .

del Hoyo, J., A. Elliot, J. Sargatal. 1994. Handbook of the Birds of the World . Barcelona: Lynx Edicons.