No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Piracy as an important foraging method of aplomado falcons in southern Texas and northern Mexico
Abstract
Piracy (kleptoparasitism) accounted for 14% of observed foraging attempts on vertebrates (n = 125) by Aplomado Falcons (Falco femoralis) in southern Texas and northern Mexico, and was over twice as successful as hunting (82% versus 37%). Aplomado Falcons pirated prey cooperatively as well as individually. Eight bird species were targeted for piracy, six of which were as large or larger than the falcons. The majority of prey items stolen were mammals.
... En algunos casos, nidos activos de ambas aves se encuentran ubicados a muy corta distancia. Al parecer, no existiría otra rapaz de hábitos solitarios y tan territorial como F. femoralis (Hector, 1981;Brown et al., 2003) que tenga este tipo de asociación reproductiva con otra ave de presa de hábitos gregarios. Como contracara de esta tolerancia interespecífica, que en algunos casos parecería ser extrema (nidos activos de ambas especies a menos de cinco metros de distancia) (De Lucca et al., 2013), se han descripto intensos encuentros agonísticos entre estas aves (De Lucca y Saggese, 1996) e incluso se ha señalado al chimango como ítem de la dieta de F. femoralis (De la Peña y Salvador, 2010). ...
... En las rapaces este fenómeno ha sido descripto ya sea cleptoparasitando a otros taxones de aves (Zuberogoitia et al., 2002) u a otras aves de presa (Jorde y Lingle, 1988;Danko, 2012), incluso, de la misma especie (Negro et al., 1992). Respecto de los falcónidos que nos ocupan, tanto F. femoralis como M. chimango piratean comida a otras rapaces (Brown et al., 2003;De Lucca, 2016) pero, al parecer, no habría registros de robo de comida entre ambas especies, más allá de dos menciones por parte del autor en un artículo previo (De Lucca et al., 2013), una de estas correspondientes al caso que aquí se presenta y la segunda, el pirateo por parte de un chimango, de un sitio de almacenamiento de comida. ...
... Luego de unos minutos de alimentación, el halcón pudo trasladar parte de la paloma a un poste de proporcionalmente grande (Lefebvre et al., 1997, Nicolakakis y Lefebvre, 2000 podría implicar un desafío mayor. Piratear a un halcón plomizo resulta meritorio, ya que esta rapaz en sí, más poderosa y agresiva que el chimango, ha sido además descripta como muy eficiente a la hora de emplear esta estrategia de obtención de comida en perjuicio de otras aves y especialmente de otras rapaces, incluso, de similar o mayor tamaño (Brown et al., 2003) por lo que sería esperable que contara con estrategias para evitar ser víctima de un accionar que tiene muy perfeccionado. Sin embargo, es oportuno señalar que existen registros de especies capaces de cleptoparasitar a otras de mayor poderío (Ratcliffe, 1993;Estrada-Devesa et al., 1997). ...
UN HALCÓN PLOMIZO (Falco femoralis) CONSUMIENDO UNA PALOMA ATROPELLADA (Columba sp.) ES CLEPTOPARASITADO POR CHIMANGOS (Milvago chimango). Aplomado Falcon (Falco femoralis) kleptoparasited by Chimango Caracaras (Milvago chimango) while consuming a run over Pigeon (Columba sp.).
... columbarius), Northern Harriers (Circus cyaneus), herons, kingfishers, and possibly a Laughing Gull (Larus atricilla) ({{{Hector 1988}biblio}bib045}, {{{Clark et al. 1989}biblio}bib015}, {{{Perez 1995}biblio}bib090}, Brown, et al. 2003, and McElroy 2008. Seventeen observations of breeding and nonbreeding Aplomado Falcons pirating prey from a variety of species in coastal Texas, including Merlins (Falco columbarius), Peregrine Falcons (Falco peregrinus), Chihuahuan Ravens (Corvus cryptoleucus), and other Aplomado Falcons (Brown et al. 2003). In south-central Chile, Raimilla et al. (2015) observed cartwheeling flight when an immature aplomado attempted to take a prey item from a White-tailed Kite. ...
... obs). Brown, et al. (2003) remarked on the low incidence of mammalian prey in diets of aplomados in Mexico and s. Texas and suggested that mammalian prey may have been pirated from other raptors like White-tailed Kites (see Kleptoparasitism above). ...
... Pairs team up to drive Crested Caracaras (Caracara plancus), other raptors, and flocks of Brown Jays from vicinities of eggs, young, and perhaps also cache sites (see Predation, below). Also takes prey carcasses from other birds (see Food habits: diet, above; and Brown et al. 2003). Sometimes interacts aggressively with Bat Falcons (D. Whitacre, G. Falxa, D. Ukrain, H. Flanders pers. ...
... Some recent anecdotal descriptions of predation on crayfish (Combarus diogenes; Clark et al. 1989), Spotted Tinamous (Nothura maculosa; Silveira et al. 1997), and lizards (Liolaemus lineomaculatus; Trejo et al. 2003) have also been published. Piracy also has been documented as an important foraging method for obtaining mammal prey from other raptors (Brown et al. 2003). However, seasonal differences in diet have not been described. ...
... Perches identified as those of Cinereous Harriers and American Kestrels were located away from (1.0– 1.5 km) known Aplomado Falcon pluck sites. In addition, Aplomado Falcons are aggressive towards other raptors (Hector 2000, Brown et al. 2003). Avian prey were identified mainly on the basis of feathers , using two complementary methods: microscopic analysis of feather structures such as nodes and barbules (Reyes 1992), and a comparison of feather coloration patterns with voucher specimens deposited in the Zoology Department of the Universidad Austral of Chile at Valdivia. ...
... Our data suggests that Aplomado Falcons in Tricauco could respond opportunistically to the availability of rodents that varies seasonally. It is possible that some rodent prey were taken by pirating from other raptors, as documented for Aplomado Falcons in southern Texas and northern Mexico (Brown et al. 2003), but we did not witness piracy in Tricauco. ...
... Множество информация за редки наблюдения на специфични поведения при царския орел и грабливите птици като цяло са посочени в множество публикации, които бяха ползвани: Dixon (1933), D'Andira (1967, Altmann (1974), Lafontaine (1976), Ali & Ripley (1978), Bildstein (1978), Brockmann & Barnard (1979), Dick & Fenton (1979), Gerrard et al. (1980), Harmata (1982), Iankov (1983), Mearns & Newton (1984), Ortega & Berkoff (1987), Blumstein (1990), Naoroji (1990), Temeles & Wellicome (1992), Simmons & Mendelsohn (1993), Janossy et al. (1993), Mrlik & Pavelka (1996), Roche (1996), Corso & Forsman (1997), Petrovicz (1998), Halley & Gjershaug (1998), Crane & Nellist (1999), Heintzelman (2001), Arroyo & Garcia (2002), Morgan et al. (2003), Pandolfi (1996), Clemons (1990), Margalida & Bertran (2003), Brown et al. (2003), Penteriani & Ferrer (2004), Kitowski (2005), Bosch et al. (2007), Danko (2007) и др. ...
... Значително по-високата успеваемост в набавянето на плячка чрез клептопаразитизъм е установена и при други видове грабливи птици. При Falco femoralis в южен Тексас и северно Мексико, клептопаразитизмът е повече от два пъти по-успешен в сравнение с ловуването (82% спрямо 37% успеваемост), (Brown et al. 2003). ...
A study on the seasonal dynamic, ecology and behavior of non-breeding Eastern Imperial Eagles in, at the time, the most important settlement area for the species in Bulgaria. Observations on pair formation among immatures and the behavior of temporary pairs. Kleptoparasitism as an important foraging strategy for the species. Interspecific relationships with other raptors.
... Aplomado Falcons also steal food from large birds including: Little Blue Heron (Egretta caerulea), White-tailed Kite (Elanus leucurus), Northern Harrier (Circus hudsonius), Peregrine Falcon (F. peregrinus) and Chihuahuan Raven (Corvus cryptoleucus; Hector 1985, Clark et al. 1989, Brown et al. 2003. ...
... The intent of interspecific agonistic behaviors can be difficult to determine because Aplomado Falcon pairs often mob avian intruders using many of the same behaviors directed at avian prey, sometimes driving the intruder to the ground (Hector 1986, Keddy-Hector et al. 2020. Similarly, pairs stealing food commonly chase and alternately strike their victim (Brown et al. 2003). Aplomado Falcons chase and attack large birds and potential predators for multiple reasons. ...
The Aplomado Falcon (Falco femoralis) is one of the few social raptors. Breeding pairs live together year-round and cooperate to hunt birds, steal prey from other birds, and defend their nests, young, cached food, and territories against predators. This mid-sized falcon can be boldly aggressive, sometimes hunting birds as large as or larger than itself or stealing prey from them. We report on a trio of Aplomado Falcons attacking and capturing a Swallow-tailed Kite (Elanoides forficatus), a raptor larger than its aggressors, in Emas National Park, Brazil. After strikes and attempted strikes by each falcon, one falcon eventually brought the kite down to the ground. The other two falcons descended to this site within seconds. Borges could not see what happened on the ground, but he was certain that no birds flew from the site for the 15 minutes that he observed afterward. Borges surmised that the falcons probably killed the kite and shared the carcass. We discuss possible motives for the attack, whether these falcons might have cooperated, and sociality in this species. (Video available as Supplemental Material.)
... Kleptoparasitism is a refined form of parasitism in which the parasite steals resources from conspecifics or other species. This behavior has been witnessed within and between many wildlife groups, including insects (e.g., ants [Formicidae]), many fishes (Teleostei), crocodilians (Alligatoridae), raptors (Falconidae and Accipitridae), squirrels (Sciuridae), carnivorous mammals (e.g., hyena [Hyaenidae]), and others (Heredia and Clark 1984, Watt et al. 1995, Jorde and Lingle 1988, Brown et al. 2003, Iyenger 2008. ...
Kangaroo rats are reported to have a mutualistic relationship with harvester ants through facilitation of burrow establishment, creation, and persistence. The relationship can, however, become more complex. We report observations of the giant kangaroo rat (Dipodomys ingens), a state and federally listed endangered species, repeatedly kleptoparasitizing harvester ants from a nearby nest in the Carrizo Plain, California. Though the relationship between kangaroo rats and harvester ants has been studied extensively and is believed to be mutualistic, under certain conditions this relationship can follow an alternate path of parasitism.
... Mohan (2004) observed 757 hunting flights by White-tailed Kites resulting in 195 captures; of the 757 it was victimized during <1% (no further details, including the kleptoparasitizing species, were reported). However, two species of raptors, the Aplomado Falcon (Falco femoralis) and Chimango Caracara (Milvago chimango), and one corvid, the American Crow (Corvus brachyrhynchos), have been reported to kleptoparasitze the White-tailed Kite (Dixon et al. 1957, Heredia and Clark 1984, Brown et al. 2003, Baladrón and Pretelli 2013. The rarity of the White-tailed Kite being a target of kleptoparasitism and our observation of the Peregrine Falcon's failing in its attempt suggest that the kite is tenacious in defending captured prey, rendering it a relatively unprofitable, seldom targeted host for potential kleptoparasites. ...
Grebes typically build floating nests that are attached to vegetation and very rarely construct nests on non-floating structures. On 29 August 2017, a pair of Least Grebes (Tachybaptus dominicus) was photographed nesting on top of a non-floating concrete structure on a sewage pond at Roatán, Honduras. This observation demonstrates that Least Grebes may nest on artificial ponds lacking sufficient vegetation for constructing and anchoring a floating nest provided that a suitable flat and hard surface is available just above the water's surface.
... Mohan (2004) observed 757 hunting flights by White-tailed Kites resulting in 195 captures; of the 757 it was victimized during <1% (no further details, including the kleptoparasitizing species, were reported). However, two species of raptors, the Aplomado Falcon (Falco femoralis) and Chimango Caracara (Milvago chimango), and one corvid, the American Crow (Corvus brachyrhynchos), have been reported to kleptoparasitze the White-tailed Kite (Dixon et al. 1957, Heredia and Clark 1984, Brown et al. 2003, Baladrón and Pretelli 2013. The rarity of the White-tailed Kite being a target of kleptoparasitism and our observation of the Peregrine Falcon's failing in its attempt suggest that the kite is tenacious in defending captured prey, rendering it a relatively unprofitable, seldom targeted host for potential kleptoparasites. ...
... Kleptoparasitism, also known as piracy or robbing, is a foraging tactic used to acquire food opportunistically from conspecifics and other species. This increases food intake while reducing the food search effort and may enable the acquisition of items not normally available through self foraging (Brown et al., 2003;Ridley and Child, 2009). Kleptoparasitism seems to be more widespread in bird species that feed on mobile prey such as insects, small vertebrates, and fish (Brockmann and Barnard, 1979, Llambías et al., 2001, Shealer et al., 2005 or on food items that are difficult to obtain and otherwise beyond the reach of the parasitic species (Barnard, 1984). ...
We describe seven instances of kleptoparasitism by the Inca dove (Columbina inca) on the red harvester ant (Pogonomyrmex barbatus) in eastern Mexico, the first documented case in the order Columbiformes and the first for ants of the genus Pogonomyrmex. Doves visited the periphery of the ants' nest entrance and fed on waste material expelled by ants from inside the nest. Doves also took seeds of the grasses Dactyloctenium aegyptium, Digitaria ciliaris, and the shrub Sida directly from Pogonomyrmex workers. During a 5-day period, we estimated that nearly 20% of the seeds harvested by ants and carried toward the nest were taken by the doves. Inca doves can be defined as facultative kleptoparasites.
... They also prey upon small mammals and shellfish occasionally (Lawrence 1874, Bendire 1892, Bailey 1928, Ligon 1961, Clark et al. 1989, Brown et al. 2004 ). Aplomados are resourceful foragers, being in the minority of falcons that successfully use kleptoparasitism (Cade 1982, Clark et al. 1989, Brown et al. 2003). Additionally, several researchers report aplomados snatching frantic prey from the edge of wildland fires (Brooks 1933, Oberholser 1974, Brown et al. 2004). ...
The northern Aplomado Falcon (Falco femoralis septentrionalis) inhabited the inland and coastal grasslands of Texas, New Mexico, and Arizona until about 1930, when records of aplomados in the United States decreased. In 1986, the species was classified as endangered under the Endangered Species Act. Among other recovery efforts, 102 birds were released from 2006 through 2011, in its former range in New Mexico at the Armendaris Ranch in the south-central portion of the state. To promote their survival, an extended supplemental feeding program was conducted. From 2006 through 2008, supplemental food was provided daily, whereas from 2009 through 2011 food was provided every other day. Providing food once daily corresponded with an increase in the known survival of the aplomados, where known survival was obtained from the recorded observations of falcons at feedings, and the establishment of nearby nesting pairs. Unfortunately, this increase in known short-term survival and reproduction did not seem to lead to long-term survival or retention. This may be attributable to a lack of available prey throughout the Chihuahuan Desert as a result of ongoing drought, significant brush encroachment caused by historic overgrazing by cattle, the eradication of prairie dogs, and decreased summer and increased winter precipitation, as well as a possible increase in predation influenced by brush encroachment and the fact that the Armendaris Ranch sits at the northernmost edge of the aplomados' historical range. If the reintroduction on the Armendaris Ranch, and other areas with similar levels of prey, is to continue, our research supports the incorporation of an extended daily supplemental feeding program and efforts to improve access to prey, possibly by removing brush and restoring grasslands.
... The northern aplomado falcon, whose range centers in Latin America, was extirpated from the United States by the 1950s (Keddy- Hector, 2000). This medium-sized (females, 406.7 g, n = 6; males, 260.5 g, n = 8), savanna-dwelling falcon specializes in hunting avian prey, often cooperatively (Hector, 1981;Brown et al., 2003). Breeding pairs are highly territorial and reside on territories year-round (Jenny et al., 2004 ...
The northern aplomado falcon (Falco femoralis septentrionalis) has been the subject of a large-scale reintroduction effort conducted by The Peregrine Fund since 1993. Intensive monitoring during 2002–2004 revealed approximately 38 breeding pairs and numerous non-territorial individuals in two study areas centered on Matagorda Island National Wildlife Refuge (NWR) and Laguna Atascosa NWR. Continued releases (“hacking”) of captive-bred young after pair establishment and successful wild breeding provided an opportunity to compare survival and recruitment histories of wild-reared and hacked falcons hatched during 2001–2003. We used Program MARK to rank multi-state models of apparent survival and recruitment rates with Akaike’s Information Criterion scores, corrected for small samples. The top model candidate, with almost 3.5 times more support than the next best model, detected differences due to falcon origin (wild or captivity): although breeder survival was independent of origin, juvenile hacked falcons survived and recruited at lower rates than wild-reared falcons. Given the high density of territorial adult falcons in the study areas, the difference in apparent survival may reflect greater dispersal by hacked falcons, increased tolerance of wild falcons in territory margins due to prior socialization, or other factors effecting higher intrinsic fitness of wild falcons. However, natal dispersal did not differ between the two groups, strengthening the hypothesis of a difference in true survival. Disproportionately greater recruitment of wild falcons into the breeding population again suggests their higher intrinsic fitness. These findings show how close monitoring of population vital rates can efficiently guide adaptive management of recovering populations.
Observations of a Peregrine Falcon repeatedly stealing prey items from White-tailed Kites.
I describe here breeding season diets of Aplomado Falcons (Falco femoralis) at 18 sites in Veracruz, Campeche, and Chiapas, Mexico, based on 256 animals in prey remains and 234 prey that I detected while watching the falcons' feeding behavior. Birds comprised 94% of individuals in prey remains, but only 35% of prey that I saw being taken. Although the remainder and majority of the prey that I saw being taken were insects, 97% of prey biomass in this sample was birds. Common prey were moths, beetles, doves, cuckoos, and grackles. Prey animals ranged in weight from less than 1 g to over 500 g. Avian prey that I saw being taken averaged 67 g. In at least one case, prey size may have influenced prey selection within species since the falcons preferentially took female Great-tailed Grackles (Quiscalus mexicanus), which are smaller than males. The swiftness of Aplomado Falcons in flight, coupled with their agility on foot and tendency to hunt cooperatively, may account for their broad prey preferences. They do not, however, capture swifts and swallows. The high proportion of birds in the diet may explain the falcon's heavy contamination with residues of DDT.
Territorial female northern harriers, Circus cyaneus, often evicted species of intruding raptors larger than themselves from their territories, but never species smaller than themselves. Contrary to the hypothesis that aggressive responses serve primarily to reduce exploitative competition, responses by harriers to larger raptor species seldom occurred during hunts by these intruders. Howerer, harriers responded frequently to larger raptor species when these species intruded while harriers were actively hunting, supporting the hypothesis that aggressive responses serve primarily to reduce interference competition in the form of kleptoparasitism of harriers' prey by larger raptor species. The lack of defence by harriers against smaller intruding raptor species apparently resulted from harriers' abilities to kleptoparasitize these intruders. Hence, whether or not a territorial harrier responded aggressively to an intruding raptor species depended on the size of the harrier relative to the size of the intruder, which in turn influenced its ability to kleptoparasitize or to be kleptoparasitized.
Aplomado falcons (Falco femoralis) formerly bred in Texas, New Mexico, and Arizona. Nesting in the U.S. was last documented in 1952. In 1986, aplomado falcons were listed as endangered and efforts to reestablish them in their former range were begun by releasing captive-reared individuals in southern Texas. From 1993-94, 38 hatch-year falcons were released on Laguna Atascosa National Wildlife Refuge. Two to 3 wk after release, 28 falcons were recaptured for attachment of tail-mounted radio-transmitters. We report on survival, movements, and habitat use of these birds. In 1993 and 1994, four and five mortalities occurred within 2 and 4 wk of release, respectively. From 2-6 mo post-release, 11 male and three female radio-tagged aplomado falcons used a home range of about 739 km2 (range = 36-281 km2). Most movements did not extend beyond 10 km from the refuge boundary, but a monitored male dispersed 136 km north when 70 d old. Average linear distance of daily movements was 34 ± 5 (SD) km. After falcons had been released 75 d, they consistently used specific areas to forage and roost. Woody plant density averaged 2.6 plants/ha on forage areas and 3.6 plants/ha at roost sites. Ground surface area was 60% vegetated in foraging areas and 46% vegetated at roost sites.
Aplomado falcons (Falco femoralis) often hunt in pairs when chasing birds; 29% of 349 hunts observed in eastern Mexico involved mated pairs of falcons simultaneously chasing the same prey animal; and 66% of 100 hunts of birds were tandem pursuits. Although true cooperative hunting is uncommon in birds of prey, hunts by pairs of Aplomado falcons consistently showed signs of cooperative behavior such as use of a simple coordinative signal, and some division of labor between participating individuals. Pairs were more than twice as successful as solo falcons hunting birds (44% vs. 19%), however, there was no evidence that cooperative hunting increased the range of feasible prey sizes. The frequent use of cooperative foraging in this and similar species may relate to necessities of efficient nest defense, and food and nest procurement in savannas inhabited by a diversity of nest-site predators.
Kleptoparasitism refers to the interspecific stealing of already procured food, but this paper shows that intraspecific food-stealing is effectively the same behaviour. A comprehensive review of the literature shows that certain orders of birds contain a disproportionate number of kleptoparasitic species. Birds in these orders occupy a limited range of ecological niches and are most commonly either predatory or dietary opportunists. Kleptoparasitism is particularly associated with certain ecological conditions, such as the availability of hosts feeding on large, visible food items and periods of food shortage. Birds show a wide range of socially parasitic feeding interactions of which kleptoparasitism is one extreme. The parasitic pattern of food-stealing is likely to involve frequency-dependent selection and may be an example of an evolutionarily stable strategy.
Falco fusco-coerulescens septentrionalis Todd: Aplomado Falcon
- A C Bent
Bent, A. C. 1938. Falco fusco-coerulescens septentrionalis Todd: Aplomado Falcon. Pp. 96–99 in Life histories of North American birds of prey, part 2 (A. C. Bent, Ed.). U. S. Natl. Mus. Bull 170. 1-482.
A contribution to the ornithology of the Orinoco region
- G K Cherrie
Cherrie, G. K. 1916. A contribution to the ornithology of the Orinoco region. Mus. Brooklyn Inst. Arts Sci., Sci. Bull 2: 133-374.
The habitat, diet, and foraging behavior of the Aplomado Falcon, Falco femoralis (Temminck). M.Sc. thesis, Oklahoma Coop
- D P Hector
Hector, D. P. 1981. The habitat, diet, and foraging behavior of the Aplomado Falcon, Falco femoralis (Temminck). M.Sc. thesis, Oklahoma Coop. Wildlife Research Unit, Oklahoma State Univ., Stillwater.
The Northern Aplomado Falcon: biology, restoration, and hacking procedures
- B D Mutch
- J P Jenny
- W R Heinrich
- C E Sandfort
Mutch, B. D., J. P. Jenny, W. R. Heinrich, and C. E. Sandfort. 2000. The Northern Aplomado Falcon: biology, restoration, and hacking procedures. The Peregrine Fund, Inc., Boise, Idaho.
The birds of the Republic of Pan-ama, part 1
- A Wetmore
WETMORE, A. 1965. The birds of the Republic of Pan-ama, part 1. Smithson. Misc. Collect. 150:1–48.
Body weights of 686 species of North American birds. Monograph 1. Western Bird Banding Association, Cave Creek The habitat, diet, and foraging behavior of the Aplomado Falcon, Falco femor-alis (Temminck). M.Sc. thesis, Oklahoma Coop The diet of the Aplomado Falcon (Falco femoralis) in eastern Mexico
- J B Dunning
- Jr Arizona
- D P Hector
DUNNING, J. B., JR. 1984. Body weights of 686 species of North American birds. Monograph 1. Western Bird Banding Association, Cave Creek, Arizona. HECTOR, D. P. 1981. The habitat, diet, and foraging behavior of the Aplomado Falcon, Falco femor-alis (Temminck). M.Sc. thesis, Oklahoma Coop. Wildlife Research Unit, Oklahoma State Univ., Stillwater. HECTOR, D. P. 1985. The diet of the Aplomado Falcon (Falco femoralis) in eastern Mexico. Condor 87: 336–342.
The falcons of the world A contribution to the ornithology of the Orinoco region
- T J Cade
- G K Cherrie
CADE, T. J. 1982. The falcons of the world. Cornell Univ. Press, Ithaca, New York. CHERRIE, G. K. 1916. A contribution to the ornithology of the Orinoco region. Mus. Brooklyn Inst. Arts Sci., Sci. Bull. 2:133–374.
The Northern Aplomado Falcon: biology, restoration, and hacking procedures. The Peregrine Fund The importance of open habitat to the occurrence of kleptoparasitism
- B D Mutch
- J P Jenny
- W R Heinrich
- C E And
- Sandfort
- D R Paulson
MUTCH, B. D., J. P. JENNY, W. R. HEINRICH, AND C. E. SANDFORT. 2000. The Northern Aplomado Falcon: biology, restoration, and hacking procedures. The Peregrine Fund, Inc., Boise, Idaho. PAULSON, D. R. 1985. The importance of open habitat to the occurrence of kleptoparasitism. Auk 102: 637–639.
Red-headed Falcon pirates prey from Montagu's Harrier
- W S And
- N J Schmitt
CLARK, W. S. AND N. J. SCHMITT. 1993. Red-headed Falcon pirates prey from Montagu's Harrier. J. Field Ornithol. 64:244–245.
Aplomado Falcon steals prey from Little Blue Heron
- P H Bloom
- L W And
- Oliphant
CLARK, W. S., P. H. BLOOM, AND L. W. OLIPHANT. 1990. Aplomado Falcon steals prey from Little Blue Heron. J. Field Ornithol. 60:380–381.
Aplomado Falcon steals prey from Little Blue Heron
- W S Clark
- P H Bloom
- L W Oliphant
Red-headed Falcon pirates prey from Montagu's Harrier
- W S Clark
- N J Schmitt