Female Falcons Research Articles

Parental Roles of Nesting Prairie Falcons in Relation to Reversed Sexual Dimorphism

Abstract In Prairie Falcons (Falco mexicanus), females are considerably larger than males, as in most diurnal birds of prey. This phenomenon, known as reversed sexual dimorphism (RSD), is usually associated with asymmetry in parental care: the smaller male provides most of the food during the nesting season, whereas the larger female incubates the eggs, and broods and protects the young. To evaluate this relationship in Prairie Falcons, we quantitatively assessed parental roles of 52 pairs of Prairie Falcons nesting in southwestern Idaho, over a 4-yr period (1984–1987). We collected behavioral observations for each pair, from the establishment of a nesting territory until young were 30–35 d old (fledging age), for a total of 613 observation days (9089 hr). We found that male and female falcons shared some tasks, although not necessarily equally, including incubation, provisioning prey and nest defense. Females accounted for two-thirds of the diurnal incubation responsibility and males for one-third. Males and females made comparable efforts in food provisioning; similarly, nest defense, here defined as aggressive interactions with (potential) nest predators, did not differ between the sexes. Other behaviors, such as brooding, hunting, and nest attendance were performed more by one sex than the other. Brooding was carried out primarily by females, and they showed consistently higher nest attendance compared to males. Males hunted significantly more than females and delivered most prey items to the nest site. Overall, sex roles exhibited by nesting Prairie Falcons in our study largely agreed with predictions based on RSD.

Natal Dispersal of Aplomado Falcons in Chihuahua, Mexico

The persistence of a species throughout its geographic range requires dispersal among its populations. The study of dispersal is particularly relevant for species whose geographic range has contracted, such as the endangered Northern Aplomado Falcon (Falco femoralis septentrionalis). We used Argos 5-g PTT-100 satellite transmitters to determine the movements of two wild Chihuahuan Desert Aplomado Falcons (one female and one male) from fledging to breeding (male), or transmitter failure (female), at 1062 d and 439 d of age, respectively. Both falcons dispersed from their natal territories 2–3 mo after fledging. These falcons then wandered between activity centers near historic breeding territories and some territories recently converted to farmlands. These two falcons also explored areas outside known breeding areas via some long-distance movements to areas of potential breeding habitat being converted to farmland. In 2 yr, movements of the male covered 7412 km2. This falcon nested unsuccessfully with an unbanded female in a vacant breeding territory 15 km from his natal site. His nesting attempt the following year yielded two fledglings. While a breeding bird, the male falcon had a home range of 200 km2. For 17 mo, the female falcon wandered through an area of 12,136 km2. The farthest distance she traveled from her nest site prior to transmitter failure was 154 km.

Home Range of an Adult Female Peregrine Falcon (Falco peregrinus) during the Breeding and Non-breeding Seasons in Kentucky, USA

The peregrine falcon (Falco peregrinus) is a Species of Greatest Conservation Need in Kentucky's State Wildlife Action Plan. The Kentucky Department of Fish and Wildlife Resources has monitored Kentucky's peregrine falcon population since 1997. However, research on the movements, habitat use, and breeding and non-breeding home range of Kentucky's nesting peregrine falcons is lacking. In this study, we used a solar-powered platform transmitter terminal (PTT) with global positioning system (GPS) and Argos capabilities to monitor the movements of a single adult, breeding female, peregrine falcon from 7 June 2015 to 4 May 2018. We found that the female falcon spent the majority of her time in close proximity to the nest site throughout the breeding and non-breeding season. Seasonal home range varied significantly with the largest home range size estimated during the post-fledging period, followed by the non-breeding season, and the smallest home range occurring during the pre-fledge period of the breeding season. We suspect that the increase in home range size observed during the post-fledging period can be attributed to parental care and post-fledge dependency of young.

Natal Dispersal of Aplomado Falcons in Chihuahua, Mexico

The persistence of a species throughout its geographic range requires dispersal among its populations. The study of dispersal is particularly relevant for species whose geographic range has contracted, such as the endangered Northern Aplomado Falcon (Falco femoralis septentrionalis). We used Argos 5-g PTT-100 satellite transmitters to determine the movements of two wild Chihuahuan Desert Aplomado Falcons (one female and one male) from fledging to breeding (male), or transmitter failure (female), at 1062 d and 439 d of age, respectively. Both falcons dispersed from their natal territories 2–3 mo after fledging. These falcons then wandered between activity centers near historic breeding territories and some territories recently converted to farmlands. These two falcons also explored areas outside known breeding areas via some long-distance movements to areas of potential breeding habitat being converted to farmland. In 2 yr, movements of the male covered 7412 km2. This falcon nested unsuccessfully with an unbanded female in a vacant breeding territory 15 km from his natal site. His nesting attempt the following year yielded two fledglings. While a breeding bird, the male falcon had a home range of 200 km2. For 17 mo, the female falcon wandered through an area of 12,136 km2. The farthest distance she traveled from her nest site prior to transmitter failure was 154 km.

Extreme territorial aggression by urban Peregrine Falcons toward Common Buzzards in South-West England

Abstract Peregrine Falcons (Falco peregrinus) breeding on a city centre church in Exeter, in the south-west of England, have been studied in detail since first occupation in 1997. During this period, changes in both male and female falcons have been recorded. Following the arrival of a new female Peregrine in 2009, a dramatic change in behaviour towards Common Buzzards (Buteo buteo) on passage over the city was noted. Buzzards flying over Exeter are attacked by the falcons, especially so when in proximity to the church. We have attempted to document these attacks through our own observations, with additional information from local residents and wildlife organisations. Further records have come from veterinary surgeries and wildlife rehabilitators regarding injured buzzards found in the city. This paper documents the extreme levels of territorial aggression as demonstrated by the pair of Peregrines during cooperative attacks on Buzzards. We reveal this unique interspecific behaviour by summarising the number, frequency, timing and outcome of attacks undertaken over an eight-year period. We describe and illustrate the strategy employed by the Peregrines during a typical attack, plus consider implications on breeding productivity and the future scenarios should one of the current pair be replaced.

Rapid Nestling Mortality in Arctic Peregrine Falcons due to the Biting Effects of Black Flies

This note describes nestling mortality in Arctic Peregrine Falcons (Falco peregrinus tundrius) due to the biting effects of blood-feeding black flies (Diptera: Simuliidae). At a nest site near Rankin Inlet, Nunavut, Canada (62˚49′ N, 92˚05′ W), a brood of four nestlings died on 20 July 2013 from the direct effects of severe bites attributed to black flies. Within three hours of the onset of blood-feeding, black flies had caused widespread, uniformly distributed hemorrhagic coalescent lesions over the head and body of all nestlings. Approximately seven hours after the first flies appeared, the female falcon removed the carcasses of the dead nestlings from the nest. Nestlings at eight additional sites also suffered the effects of biting black flies in 2013, resulting in the deaths of 13 of 35 nestlings. A less pronounced outbreak also occurred in 2012 and resulted in the deaths of seven nestlings at four sites. No nestling mortality due to black flies has been documented in any other year from 1982 through 2015. To our knowledge, these observations document the northernmost lethal attack by ornithophilic black flies in North America.

Humoral Response of Hybrid Falcons Inoculated With Inactivated Paramyxovirus-1 Vaccine

Paramyxovirus serotype 1 (PMV-1), the etiologic agent of Newcastle disease, is an important cause of morbidity in falcons in the Middle East. To determine whether a commercial, oil-based, inactivated poultry vaccine produces humoral response in falcons, we vaccinated 38 young, unvaccinated gyr-peregrine hybrid falcons (Falco rusticolis X Falco peregrinus) and monitored antibody response for a 45-day period after vaccination. To determine whether immunity is vertically transmitted, we additionally tested the yolks of 15 unfertile eggs of falcons vaccinated 5 months previously. All testing was done by commercial enzyme-linked immunosorbent assay for PMV-1 antibody designed for use in poultry. In the vaccinated falcons, serum antibody levels to avian PMV-1 increased by day 14 after vaccination, and titers continued to increase until day 45 when the study ended. Five percent of birds failed to seroconvert. Adult female falcons vaccinated with inactivated vaccine produced eggs with high antibody levels. The inactivated vaccine caused no detectable adverse affects in the gyr-peregrine hybrids.

Urinalysis as a Noninvasive Health Screening Procedure in Falconidae

Clinical signs of renal disorders in animals, including raptors, are not specific. Furthermore, serum or plasma biochemical parameters change only when 70% of kidney function is lost. In this study, reference values of urine variables were established in clinically healthy falcons. Urine samples were collected from 78 mature (> 1 year) and immature (6-12 months) male and female falcons belonging to 5 species. Droppings were assessed visually for urate color and consistency and color of the liquid urine. The liquid urine was collected by aspiration into a syringe and centrifuged, and the supernatant analyzed by commercial dipstick and by a wet chemistry analysis for alkaline phosphatase, gamma glutamyl transferase, glucose, chloride, and total protein concentrations. Sex, age, and species did not affect results of biochemical urine values (P > .05). Urine biochemical values did not differ significantly between fasted and fed birds. Total protein levels in urine samples decreased after 24-hour storage at 4 degrees C. Reference ranges for clinically normal birds are reported.

Le rituel de la fête du 5 Paophi

According to festival calendars of temple of Dendera, Hathor emerges on 5 Paophi as lady of menat, sovereign of horns and takes on form of a female falcon. Other sources call this day the day of bringing t?-plants. The texts of crypts of temple of Dendera enable us to reconstruct an offering ritual dedicated to Hathor. The same group of scenes can be found in House of Menat inside temple. On both occasions, Hathor appears as female falcon. Moreover, this ritual can be located on walls of temple of Edfu where it is combined with scenes referring to three other mayor festivals of Hathor (New Year, Epiphi and 20 Thot) that are described by ritual texts in pronaos of Dendera.

Falcon Adenovirus Infection in Breeding Taita Falcons (Falco Fasciinucha)

Four female and 3 male Taita falcons (Falco fasciinucha) out of a breeding colony of 14 Taita falcons (7 pairs) died during the breeding season after showing lethargy and anorexia for 1 to 2 days. All animals were submitted for necropsy. Gross lesions in the female falcons were characterized by anemia secondary to marked hemorrhage into the ovary and oviduct, serofibrinous effusion into the cardioabdominal cavity and serosal petechiae. In addition, marked necrotizing splenitis and pulmonary hemorrhage were present. Histologically, the female falcons had mild necrotizing hepatitis with numerous intranuclear inclusion bodies and necrotizing splenitis with rare inclusion bodies. There were no gross lesions in the male falcons, and the histological lesions were characterized by urate deposition and rare intranuclear inclusion bodies in the renal tubular epithelial cells. Adenoviral particles were found by electron microscopy in the cloacal contents of the female Taita falcons but not in the male falcons. DNA in situ hybridization revealed widespread aviadenoviral nucleic acid within the nuclei of hepatocytes, renal tubular epithelial cells, and adrenal cells in the female falcons but no aviadenoviral nucleic acid in 1 male falcon and only a low quantity of adenoviral nucleic acid in the liver and kidney of another male Taita falcon. PCR amplified aviadenoviral DNA in the liver and intestine of all Taita falcons. The amplicons were sequenced, and the virus was identified as falcon adenovirus. The deaths of the female and male birds were attributed to the aviadenovirus infection.

Use of sex-linked minisatellite fragments to investigate genetic differentiation and migration of North American populations of the peregrine falcon (Falco peregrinus).

The M13 repeat detects different levels of genetic variation in falcons. First, this minisatellite probe reveals typically highly variant restriction fragments that show no apparent unequal distribution between the sexes. Secondly, the M13 repeat detects sets of fragments that are only present in DNAs from female falcons. The level of polymorphism displayed by the sex-linked fragments is greatly reduced relative to most autosomal minisatellites. In addition, the size of these fragments (in kilobase pairs) is species-specific among Mauritius kestrels (Falco punctatus) and peregrines (Falco peregrinus). Variation observed at one o of the sex-linked fragments in peregrines has proven to be useful in distinguishing a subset of the tundrius subspecies of this endangered raptor. This correlation has enabled a genetic test to be used to examine the representation of tundrius peregrines during mass migration.

Studies on the blood sugar and rest reduction in falcon

1. The normal blood sugar of falcon was determined and found to have an almost unconstant value. It ranges between 198 and 257 mg per 100 c.cs blood in male and female falcons. 2. Starvation for 24 and 48 hours has no effect on the blood sugar level. 3. Sex and seasons are with no effect on the blood sugar of falcon. 4. After feeding the blood sugar of falcon begins to rise two hours after feeding. The rise continues till reaches its maximum 16 hours after feeding. The blood sugar level then begins to fall gradually and reached the normal level 22 hours after feeding. 5. The rest reduction determined after 24 and 48 hours starvation is the same and it amounts 18 mg per 100 c.cs blood.