Crotophaga Ani Research Articles

Competition and waste in the communally breeding smooth-billed ani: effects of group size on egg-laying behaviour

We investigated the effects of group size on egg-laying behaviour in the communally breeding, joint-nesting smooth-billed ani, Crotophaga ani. We tested the predictions of the competitive female egg-investment hypothesis, which states that females in plurally breeding, joint-nesting systems respond to increased group size and egg-laying competition by trying to skew the contents of the final incubated clutch of eggs in their own favour by tossing and/or burying competitors' eggs and by producing more of their own eggs. Results supported the predictions of the hypothesis as both the number of eggs produced per capita and the number of eggs lost per capita increased with increasing group size. Egg tossing and burial behaviours were almost entirely restricted to multifemale groups and 56% of the 829 eggs laid in communal nests were lost to either egg tossing or burial. As a consequence of this egg-laying competition, the number of eggs incubated per capita decreased with increasing group size. Large groups laid more eggs and took more time to synchronize laying than smaller groups. Finally, we found that chicks hatched late within a communal clutch were more likely than earlier hatching chicks to die during the first 5 days of life. We conclude that communal life in anis generates competition and egg production waste that reduces short-term per capita reproductive benefits. Long-term data are needed to clarify individual benefits associated with communal breeding in this species.

Validated cleaner: the cuculid bird Crotophaga ani picks ticks and pecks at sores of capybaras in southeastern Brazil

Information on the role of smooth-billed anis (Crotophaga ani) as tick-pickers on mammals remains controversial. I record here these birds removing ticks and pecking at wounds of capybaras (Hydrochoerus hydrochaeris) in a small reserve at Campinas, São Paulo, southeastern Brazil. The birds inspected the mammals’ skin, both in places with and without hair. The hair was parted with bill movements, and ticks were removed by vigorous pulling. The birds also pecked at open or healing sores, from which they extracted small portions of blood clots and dead tissue. The capybaras appeared oblivious to the birds’ activity. Even in the case that the cleaning behaviour is restricted to some bird individuals and populations, or places and periods, this record validates the notion that smooth-billed anis removes ticks from herbivorous mammals.

Do group size and laying order influence maternal deposition of testosterone in smooth-billed ani eggs?

The avian egg contains maternal hormones that affect behavior, growth, morphology, and offspring survival. Evidence to date suggests that patterns of yolk androgen deposition could provide females with a means to manipulate sibling competition and, thereby, increase their fitness. We examined yolk testosterone (T) concentrations in eggs of the smooth-billed ani ( Crotophaga ani) to understand patterns of androgen deposition in eggs of this plural-breeding joint-nesting cooperatively breeding species. We tested the hatching asynchrony adjustment hypothesis, which states that increases in yolk androgen levels over the laying sequence function to mitigate the disadvantage of being a later-hatched chick in species without adaptive brood reduction. We also investigated the effect of group size on yolk T deposition to test the hypothesis that females in multi-female groups could give a competitive edge to their own chicks by depositing higher T levels in their eggs. Predictions of the hatching asynchrony adjustment hypothesis were supported in both single- and multi-female groups as yolk testosterone levels increased from early- to late-laid eggs. This suggests that ani females can influence nestling competition and chick survival by within-clutch differential T allocation. Unexpectedly, we did not observe an effect of group size on yolk T deposition. Yolk testosterone concentrations may not be a mere reflection of a female's hormonal status as female plasma circulating levels of T did not vary in the same direction as yolk T levels. Results of this study therefore support the idea that females may adaptively manipulate chick behavior through hormonal deposition in eggs.

Phylogeny of cooperatively breeding cuckoos (Cuculidae, Crotophaginae) based on mitochondrial gene sequences

The Crotophaginae is a subfamily of New World cuckoos comprising the monotypic genus Guira and three ani species ( Crotophaga). All exhibit a rare form of cooperative breeding known as plural female joint-nesting, whereby two or more females lay eggs in a single nest. I reconstructed the phylogeny of Crotophaginae using the mitochondrial genes cytochrome oxidase I, II, and III, ATPase 6 and 8, and cytochrome b. The subfamily was monophyletic, implying a single origin of cooperative breeding in New World cuckoos. Crotophaga was also monophyletic with Guira as its sister taxon. Within Crotophaga, the smooth-billed ( C. ani) and groove-billed ( C. sulcirostris) anis formed the internal clade with the greater ani ( C. major) basal to this pair. This phylogeny is consistent with differences in reproductive patterns and social organization exhibited by crotophagine cuckoos, and will serve as a framework for future study of the evolution of cooperative breeding in this subfamily.

The characterization of microsatellite loci in the communally breeding smooth‐billed ani (Crotophaga ani)

AbstractMicrosatellite DNA sequences were isolated and characterized from a Puerto Rican population of communally nesting smooth‐billed anis for use in a parentage/kinship study. Lambda Zap Express (Stratagene) was used to construct a library of 350 000 independent recombinant phage and screened with TG and AAT probes. In total, 85 positive clones (73 TG and 12 AAT) were isolated. Primer pairs were designed for 17 sequences and five polymorphic loci were found (three TG and two AAT). The five loci were characterized with between four and nine alleles and heterozygosity values ranged from 0.538 to 0.840. The combined total parental exclusionary power (with neither parent known) of the five loci was 0.8869.

Smooth-billed ani ( Crotophaga ani ) predation on butterflies in Mato Grosso, Brazil: risk decreases with increased group size

Although most insects are vulnerable to predation by a variety of predators, including birds, there are few direct observational studies in the wild of avian predation on adult butterflies. We examined the predatory behavior of smooth-billed anis (Crotophaga ani) on butterflies, and the spacing behavior of the butterflies which were concentrated on a mineral-rich beach on the Cristalino River, in Mato Grosso, Brazil. We studied eight of the most regularly occurring butterfly species which came each morning to engage in "puddling." Most species of butterfly were closely associated with conspecifics, although nearest-neighbor distance varied among species. The pierids – "yellows" (Aphrissa statira, Phoebis trite), "oranges" (Phoebis argante), and sometimes "whites" (Daptoneura leucadia) – formed very dense groups (or clusters) of up to 1,000 individuals occasionally joined by a few kite swallowtails (Eurytides spp.). Most other butterfly species formed small groups (e.g., daggerwings, Marpesia spp.) or were dispersed individually and non-clumped over the beach (e.g., dingy purplewing, Eunica monima). Anis foraged using two strategies: rapid frontal attack on dense groups of butterflies (yellows, oranges, whites), and a stealthy approach to solitary butterflies (mainly purplewings) or those in small groups. For yellows, the most common butterfly caught by anis, the capture rate reached over 6 per 15 min per ani, and about 8% of those captured managed to escape. Capture rates were much lower for the other species. Time of day, age of the ani (adult or young-of-the-year), and total number of each butterfly species present accounted for variation in the number of each species captured by anis. The number of butterflies captured per 15 min increased as the number of butterflies present increased, but reached a threshold beyond which the capture rate did not increase. The capture rate per individual butterfly (individual risk) decreased with group size up to a group of 40 individuals and remained low with further increases. Thus a butterfly in a group of 100 was no less likely to be eaten than one in a group of 40. For individual ani forays into dense groups of pierids, an individual ani was unable to catch more than 16, regardless of group size. These data confirm the dilution effect of group size for butterflies; each individual yellow or orange was less at risk from ani predation when in a group.

The price of eggs: increased investment in egg production reduces the offspring rearing capacity of parents

Understanding the selective pressures shaping the number of offspring per breeding event is a key area in the study of life-history strategies. However, in species with parental care, costs incurred in offspring production, rather than rearing, have been largely ignored in both theoretical and empirical studies until relatively recently. Furthermore, the few experimental studies that have manipulated production costs have not yet teased apart effects that operate via the parental phenotype from effects on the quality of the resulting young. To examine whether increased egg production influences parental brood rearing capacity independently of effects operating via egg quality, we experimentally increased egg production in gulls and then examined their capacity to rear a control clutch. We found that the capacity of parents to rear the control brood was substantially reduced solely as a consequence of having themselves produced one extra egg. The paradox that, in many species, parents apparently aim for fewer young per breeding event than the experimentally and theoretically demonstrated optimum, has partly arisen from the failure to take into account the constraints imposed by production costs.

The Trematode Fauna of an Amazonian Antbird Community

Parasites have been used as a tool to study the phylogeny of avian hosts (e.g. Baer and Mayr 1957). Differences between the parasite faunas of two host species could reflect differences in genetic susceptibility to the parasites or could be the result of differences in host feeding habits, habitat preferences, or behaviors. While studying habitat partitioning among 38 antbird species in eastern Ecuador, we collected the birds' trematode parasites. We were particularly interested to learn what ecological and taxonomic conclusions might be drawn from the trematode distributions among the hosts. Methods and Materials.-Antbirds were collected from September 1975 through November 1976 in a relatively undisturbed moist tropical forest (sensu Holdridge 1967) in the vicinity of Limoncocha, a village in the Provincia Napo in east-central Ecuador (0?24'S, 76?37'W; 300 m elevation). Specimens of antbirds that served as hosts are housed at the Louisiana State University Museum of Zoology, Baton Rouge, and at the Universidad Catolica, Quito. Hosts were examined for parasites as soon as possible after being killed (never more than 8 h after death). We examined the digestive tract and associated organs, lungs, air sacs, body cavity, kidneys and associated ducts, and the female reproductive tract. Differences in parasite populations from different hosts were evaluated using a one-way analysis of variance (ANOVA). Results. -Thirty-eight species of antbirds have been reported from Limoncocha, Ecuador (Table 1). We examined 358 specimens of 35 antbird species for parasites. Of these, 123 individuals of 27 species contained trematodes. Eleven trematode species were extracted from the antbirds. The occurrence of these parasites ranged from rare (of incidental distribution and in small numbers), to intermediate (in scattered hosts and with larger numbers of individuals per host), and to common (widely distributed among hosts and found in large numbers). A list of parasites, hosts, incidence of infections, and infection sites is provided in Table 2. Two trematode species were rare among the antbirds. Two immature specimens of Echinostomatidae were found in the kidneys of one Myrmeciza hyperythra host, and one gravid specimen of an undetermined species of Brachylaimidae was retrieved from one Formicarius analis. Six parasites were intermediate in occurrence. Lubens lubens was found in Gymnopithys, Thamnomanes, and Phlegopsis hosts. The measurements of these specimens greatly overlapped. Hylophylax gall bladders contained a much smaller Lubens, which possibly could be a distinct species, but probably is a size variant of L. lubens, since L. lubens is a variable species (Travassos 1944; see Table 3). Although formerly unreported from Formicariidae, L. lubens is known from a wide variety of birds (Travassos et al. 1969). Neodiplostomum ellipticum was found in moderate numbers in two individuals of Percnostola leucaspis. These trematode specimens fit the description for N. ellipticum given by Travassos et al. (1969). Neodiplostomum ellipticum is known from Brazil, Venezuela, and Jamaica from anis (Crotophaga ani and C. major) and the Squirrel Cuckoo (Piaya cayana), all of which occur at Limoncocha (Travassos et al. 1969, Yamaguti 1958). The Neodiplostomum specimens from Myrmeciza (Table 4) were consistently much larger than N. ellipticum or any other Brazilian Neodiplostomum described by Travassos et al. (1969), with the exception of N. tamarini, a parasite of primates. However, N. tamarini has the posterior testis with a median lobe, a characteristic absent in the Myrmeciza trematode specimens. For these reasons, we believe the Neodiplostomum specimens found in Myrmeciza represent an undescribed species. Brachylecithum rarum was found in the livers of Formicarius and Chamaeza hosts. Our material from Formicarius is similar to that figured in Travassos et al. (1969) and in Denton and Byrd (1951). Although the eggs in our sample appear to be relatively small, the measurements for all other features overlap those reported in the literature for Brachylecithum rarum (Table 5). These parasites were easily fragmented. We have no whole specimens from Chamaeza; the measurements of these fragmented worms suggest they are not statistically different from Brachylecithum in Formicarius. The parasite is known from Brazil, where it has been recovered from bile capillaries of various members of the order Passeriformes (Travassos et al. 1969), and from North America, where it has been found in Rufous-sided Towhees (Pipilo erythrophthalmus; Denton and Byrd 1951). An unidentified species of Leucochloridium occurred in Hylophylax, Myrmeciza, Myrmoborus, and Myrmotherula. Although similar in shape to L. parcum from Brazil, our material is larger bodied, with a smaller acetabulum and oral sucker, and much smaller eggs (Table 6). Despite small sample sizes from different hosts, there is little variation among the specimens. We suspect that these specimens represent an undescribed species of Leucochloridium.

Helping is costly to young birds in cooperatively breeding white-winged choughs

Cooperative breeding among birds is at its most extreme in white-winged choughs ( Corcorax melanorhamphos ). Choughs have never been observed to breed successfully without helpers, and reproductive success increases linearly across all group sizes (maximum = 16). Further, helpers contribute to every aspect of reproduction, including nest building and incubation. Here we show that the contribution of young helpers (one year old and less) to incubation depends on the group in which they live. In small groups (3-5 birds), young helpers contribute as much to incubation as older birds, but in large groups they contribute little. In large groups, help increases sharply with age. Old birds contribute equally, regardless of group size. Although choughs generally do not lose body mass over incubation, young helpers lose mass in proportion to the amount of incubation they perform, independent of any effect of group size. This provides evidence that helpers in cooperatively breeding birds suffer costs from providing help additional to the costs incurred from remaining philopatric. It also demonstrates that the needs of the group influence whether young birds provide help.

Commensal feeding associations between Yellow Wagtails Motacilla flava and cattle

Commensal ‘beating’ associations in which one party exploits prey disturbed by the other seem to be fairly common in terrestrial habitats (e.g. Dean and MacDonald 1981). Most such commensal relations appear to be opportunistic phenomena, rather than regularly occurring associations with possible fitness effects for the commensal, but few of them have been studied in detail. Exceptions are a few apparently very regular associations, for example those between birds and army ants (e.g. Willis 1966, Willis & Oniki 1978), between anis Crotophaga spp and cattle (Rand 1953, Smith 1971) and, especially, between Cattle Egrets Bubulcus ibis and large herbivorous mammals (for references, see Kushlan 1978). In the latter two cases, clear advantages in the form of higher food intake rates have been demonstrated for individuals foraging commensally (Rand 1953, Heatwole 1965, Smith 1971, Dinsmore 1973, Grubb 1976, Burger & Gochfeld 1982).

The distribution and abundance of the smooth-billed ani Crotophaga ani (L.) in the Galapagos Islands, Ecuador

The smooth-billed ani Crotophaga ani (L.) was apparently brought to Santa Cruz Island, Galapagos from mainland Ecuador by farmers hoping to alleviate tick problems on their cattle. Anis first appeared in the early 1960s but were not reported again until the late 1970s. After heavy rainfall during the 1982–1983 El Nino event, the ani population increased rapidly to an estimated 800 birds on Santa Cruz and the birds invaded other islands. Anis were known to be breeding only on Santa Cruz and probably Isabela during our census in 1986; however, other islands have been invaded recently and several of these are likely to provide suitable habitat. We estimated 4800 anis in the farm zone of Santa Cruz, where the population density was greatest. On Isabela we estimated there were approximately 100 birds, primarily in the farm zone. Principal food items in the diet were grasshoppers (Orthoptera), caterpillars (Lepidoptera) and spiders (Araneae). Their diet overlaps with native bird species. Potential threats to the Galapagos ecosystem include competition with the native bird fauna, seed dispersal of introduced plants and introduction of avian diseases. We recommend that the ani be eliminated from the Galapagos Islands.

Nocturnal Hypothermia and Oxygen Consumption in Manakins

-Red-capped Manakins (Pipra mentalis) and Golden-collared Manakins (Manacus vitellinus), two species of small, frugivorous, tropical passerines, showed facultative hypothermia and reduced oxygen consumption at night. The lowest body temperature measured in M. vitellinus (30.5”C, when the ambient temperature was 19.5”C) represents a reduction of more than 40% in the difference between body temperature and ambient temperature. Under these circumstances, a reduction of more than 40% in the rate of oxygen consumption would also occur during the period of regulated hypothermia. Even moderate hypothermia at ambient temperatures typical of the lowland tropics substantially reduces the energy expenditure of a resting bird. Hypothermia (lowered body temperature) has been regarded as an adaptive response by an organism to varying combinations of environmental and internal conditions that cause energy shortages either on a daily or a seasonal basis. Such factors include (1) small size because of the high mass-specific metabolism associated with it and the inability of small organisms to carry large energy reserves either as fat or in the gut, (2) insectivory or nectarivory and associated extreme fluctuations in the availability of food and/or rapid passage of food through the gut, (3) low ambient temperature (T& and (4) types of inclement weather that prohibit foraging and/or increase heat loss (see Bartholomew 1972, Hainsworth and Wolf 1978). Degrees of hypothermia have been documented in at least eight avian orders. In the Caprimulgiformes and in the Apodiformes (Trochilidae), body temperature (TJ may drop below 20°C and sometimes approach ambient temperature (even T,‘s as low as 7°C). More moderate nightly drops in T, to between 20 and 30°C have been reported in the Coliiformes, Columbiformes, Apodiformes (Apodidae), and Passeriformes (Nectarinidae). Diurnal cycles in normothermic T, are well known, however, and it is not yet possible to distinguish clearly between these cycles and the varying degrees of nocturnal hypothermia (T,,‘s as low as 30°C) reported in Cuculiformes, Falconiformes, Strigiformes, and the passerine families Nectariniidae, Hirundinidae, Paridae, Ploceidae, and Fringtlhdae. (See Dawson and Hudson [1970], Calder and King [1974], Chaplin [1976], and Biebach [1977].) In lowland tropical environments, ambient air temperatures rarely drop more than 15-20°C below the T, of normothermic birds. Since the rate of heat production in endotherms is proportional to the difference between T, and T,, a decrease of 8-10°C in regulated T, would decrease this difference by half and would yield an energy savings of about 50% during the period of hypothermia. Such fluctuations in T, have been reported in the Smooth-billed Ani (Crotophaga anz] in Panama (Warren 1960) and several Brazilian hummingbirds (Morrison 1962). We document here similar low nocturnal T,‘s in two species of small, tropical passerines, the Red-capped Manakin (Pipra mentalis) and the Golden-collared Manakin (Manacus vitellinus). These birds are common in the understory of second-growth forests in Panama and are almost entirely frugivorous. Because food passes through their gut very rapidly (in about 18 min), their feeding bouts are brief but frequent throughout the day (Worthington, in press). Thus, manakins are vulnerable to daily and seasonal food shortages (Foster 1977; Worthington, in press). Vleck and Vleck (1979) suggested that manakins may reduce their resting metabolic rate to ameliorate the effects of such energy shortages. Our study was undertaken to examine this possibility, and our data demonstrating hypothermia and associated low metabolic rates support their suggestion. MATERIALS AND METHODS Birds were mist-netted on Barro Colorado Island, Panama (9”N, SO’W). Three individuals (1 s and 1 P P. mentalis, 1 P M. vitellinus) were maintained in captivity for at least one week before we measured their rates of oxygen consumption (VoJ. On some occasions an individual was fasted from noon until

The Dwarf Cuckoo in Venezuela

The Dwarf Cuckoo (Coccyzus pumilus) is a poorly known species; the only detailed observations of its breeding biology were made near Cali, Colombia by Ralph (Condor 77:60-72, 1975). Meyer de Schauensee (The species of birds of South America with their distribution, Livingston Publishing Co., Narberth, Pa., 1966) reported it as found in parts of Colombia and Venezuela in tropical and occasionally subtropical zones. Phelps and Phelps (Lista de las aves de Venezuela con su distribucion, Tomo 2, Parte 1, Bol. Soc. Venez. Ciencias Nat., 19, No. 90, 1958) described it as very locally distributed in Venezuela. I made the following observations on Fundo Pecuario Masaguaral, a cattle ranch in the state of Gu~irico, central Venezuela. This ranch is in the Venezuelan Ilanos, an extensive low-altitude grassland with scattered trees and occasional gallery forests. The habitat is designated as dry tropical woods by Ewel and Madriz (Zonas de vida de Venezuela, Ministerio de Agricultura y Cria, Republica de Venezuela, 1968). The llanos have a highly seasonal hydrology; rains from May through October flood the ground in places to a depth of over 50 cm; the other six months of the year are extremely dry. On the morning of 19 July 1973, I observed a Dwarf Cuckoo perched in some dense thorny bushes surrounding the base of an isolated palm tree in an area where the seasonal water was more than 30 cm deep. While preening, the cuckoo occasionally uttered a five to six note rattling churr. This call resembles a portion of the vocal duet of the White-bearded Flycatcher (Myiozetetes inornata), a permanent resident of the area. Another cuckoo answered briefly from the far side of the bushes. Ralph interpreted this call as a pair contact. The preening bird made another sound at about 11-sec intervals, a low single click which was accompanied each time by a shake of its body. Probably this is the same vocalization characterized by Ralph as cluck or tok. Later I found a nest in the same bushes, but on the side facing an open marsh. It was placed in a horizontal crotch of thorny branches at a height of 2 m. The nest was about 18 cm in diameter and constructed of small sticks so loosely put together that sky could be seen through it. A young cuckoo crouched on the supporting branch beside the nest. The juvenile cuckoo had a pale gray head and nape, and light brown back, wings and tail. Below, it was dirty white, entirely lacking the orange rufous throat and upper breast of the adult. The eye ring, which is red in the adult, was dull yellow. When the young bird heard the low clicks of an adult it became excited, gaped, then flew or glided down into the foliage. An adult cuckoo guarded the nest area, sometimes with vigor. A Smooth-billed Ani (Crotophaga ani) flew into the bushes and was immediately attacked and driven away. At another time a Gray-capped Cuckoo (Coccyzus lansbergi) landed in the bushes, but it left in haste after only a few seconds. On the other hand, a pair of preening Scaled Doves (Scardafella squammata) was tolerated in the nest bush and a pair of Pied Water-Tyrants (Fluvicola pica) nesting 4 m away was unmolested. About half an hour after I found the juvenile, an adult cuckoo, which proved to be male, flew into the bush with a large moth in his bill. The moth was buff-colored with a thick furry body about 3 cm long. The cuckoo called and was answered, then a second adult cuckoo met it on a small horizontal branch. The pair perched side by side and engaged in an active tug-of-war, each alternately pulling the moth. The male jerked the moth free and then both birds flew to a higher perch. While the moth struggled, the male cuckoo mounted the female, who grasped the insect's body as they copulated. When they separated, the male was still holding the moth, but the female pulled it away from him and tried to eat it. The moth freed itself and dropped down into thick foliage where the female cuckoo followed

Predatory Behavior of Smooth-Billed Ani

Predatory Behavior of Smooth-Billed Ani

The Relationship of Grazing Cattle to Foraging Rates in Anis

MANY species of birds regularly forage on organisms that have been flushed by a source other than the birds themselves. This source may be nonliving; Stevenson and Meitzen (1946) report White-tailed Hawks (Buteo albicaudatus) coming from as far as 10 miles to follow grass fires in Texas. Similarly, raptors often follow trains to feed on animals they flush; see, for example, Kenyon's (1942) work on Pigeon Hawks (Falco columbarius). More commonly, the source is living. A large complex of neotropical birds depends for their food upon arthropods flushed by swarms of army ants (Willis, 1967, 1968). Certain old world hornbills, drongos, and leafbirds follow troops of monkeys to obtain the insects they disturb (Chapin, 1939; Stott, 1947). Many of these feeding associations involve large ungulates. The Brown-headed Cowbird (Molothrus ater) originally fed in close association with bison; in modern times this association has shifted to cattle. Many species of herons also feed with cattle; probably the best known of these is the Cattle Egret (Bubulcus ibis). Finally two tropical American cuckoos, the Groove-billed Ani (Crotophaga sulcirostris) and the Smooth-billed Ani (Crotophaga ani), regularly forage with domestic cattle wherever cattle have been introduced into their normal range. Heatwole (1965) showed that Cattle Egrets in Puerto Rico are benefited in both time and energy by their association with cattle. Rand (1953) showed that the association between Groove-billed Anis and cattle in El Salvador was correlated with a greater feeding rate by the anis at any time of year, but the benefit was greater in the dry season than in the wet season. Very little other work has been done to determine the amount of benefit the foraging birds gain by this practice. The present study was conducted from this point of view on both species of ani in Costa Rica during the wet season of 1969. Each species of ani was watched both foraging with cattle and foraging alone to determine whether or not these birds derive any measurable benefit from their association with cattle. The foraging habits of the two ani species, as described in detail by Bent (1940), are remarkably similar: both regularly forage in small groups of 6 to 10 birds; both are ground feeders; and both are primarily insectivorous, grasshoppers and other orthopterans making up large proportions of the diet of each. Anis of both species, when foraging with grazing cattle, stay very close to the head or front legs of the

Another Nest of the Smooth-Billed Ani, Crotophaga ani, in Florida

Another Nest of the Smooth-Billed Ani, Crotophaga ani, in Florida

Additional Recent Observations on the Smooth-Billed Ani in Florida

Additional Recent Observations on the Smooth-Billed Ani in Florida

Smooth-Billed Ani in Florida

Smooth-Billed Ani in Florida

The Edibility of Birds: Illustrated by Five Years' Experiments and Observations (1941–1946) on the Food Preferences of the Hornet, Cat and Man;and considered with Special Reference to the Theories of Adaptive Coloration

The Edibility of Birds: Illustrated by Five Years' Experiments and Observations (1941–1946) on the Food Preferences of the Hornet, Cat and Man;and considered with Special Reference to the Theories of Adaptive Coloration

Immature Smooth-Billed Ani in Florida in 1897

Immature Smooth-Billed Ani in Florida in 1897