White-crowned Pigeons Research Articles

Sustainability assessment of Plain Pigeons and White-crowned Pigeons illegally hunted in Puerto Rico

ABSTRACT The Puerto Rican Plain Pigeon (Patagioenas inornata wetmorei) and the White-crowned Pigeon (P. leucocephala) are hunted illegally in Puerto Rico, despite being protected. Data are lacking to estimate how many are hunted illegally each year. For this reason, we used abundance estimates derived from distance sampling surveys conducted in 1986–2014 to (1) fit a Bayesian state-space model, (2) estimate posterior distributions for population and harvest management parameters (e.g., growth rate, carrying capacity, and maximum sustainable harvest rate), and (3) predict abundance in 2025 as a function of potential illegal hunting in 2015–2024. For the Plain Pigeon and White-crowned Pigeon, respectively, the intrinsic rate of population growth was 0.351 (95% credible interval = 0.086–0.737) and 0.352 (0.094–0.699), population carrying capacity was 55,840 (29,649–96,505) and 73,692 (47,225–98,434) individuals, maximum sustainable harvest rate was 0.176 (0.043–0.369 and 0.047–0.349), and predicted abundance...

Abundance and Distribution of Mangrove Landbirds in Florida

Abstract Florida's mangroves provide habitat for an eclectic mix of bird species, including five taxa rarely found elsewhere in North America. Little is known of the natural history of any of these birds, which poses an obstacle to effective conservation. To help fill some of the basic gaps in our understanding of this avifauna, we conducted extensive surveys in Florida's mangroves during 2008–2011, with the goals of quantifying distribution and estimating breeding-season abundance of mangrove landbirds. We detected 80 species in the mangroves during the breeding season; most were species in Passeriformes (n = 29), but other important taxa included Ciconiiformes (n = 13) and Charadriiformes (n = 12). We focused our analysis on the 18 landbird species (including members of Falconiformes, Columbiformes, Cuculiformes, Piciformes, and Passeriformes) that had >90 detections and that were detected at >5% of the survey points. The landbird avifauna of Florida's mangroves is lower in both species richness and total number of individuals than other vegetation types of southern Florida. The breeding assemblage of mangrove landbirds was dominated numerically by four species that accounted for 58% of all detections of landbirds (this same group accounted for 52% of detections of all species encountered): red-bellied woodpecker Melanerpes carolinus, northern cardinal Cardinalis cardinalis, Florida prairie warbler Setophaga discolor paludicola, and white-eyed vireo Vireo griseus. Only Florida prairie warbler is restricted to mangroves; the other three species are common throughout much of eastern North America. Each of these species was also widely distributed in the mangroves. Of the other species unique to the mangroves of Florida, black-whiskered vireo Vireo altiloquus was widespread but was less abundant than Florida prairie warbler. White-crowned pigeon Patagioenas leucocephala, gray kingbird Tyrannus dominicensis, and Cuban yellow warbler Setophaga petechia gundlachi were detected only in the Florida Keys and on the islands of Florida Bay, but were found in high densities where present. Mangrove cuckoo Coccyzus minor was found throughout the mangroves but occurred at very low density and at only a small percentage of survey points. Overall, mangrove landbirds reflect the biogeographic condition common throughout southern Florida, in which largely temperate faunas coexist with largely tropical floras. The predominance of temperate species in Florida's mangroves has produced an avifauna apparently more species-rich than that found in the mangroves of West Indian islands, which include additional tropical species but no species of temperate origin.

Sonnet For The White-Crowned Pigeon

Sonnet For The White-Crowned Pigeon

Conservation Implications of the Current Breeding Distribution and Abundance of the White-crowned PigeonPatagioenas leucocephalaat St. Croix, US Virgin Islands

Road and non-roadside surveys of breeding White-crowned Pigeons Patagioenas leucocephala were conducted on St. Croix from April through September 2002 and 2003. Confirmed or probable breeding birds were discovered at 15 sites, including all four cays off St. Croix, and two sites in the interior (21–25 m asl) where this species had not bred previously. An estimated 160–175 pairs nested each year, although numbers were low (1–10 pairs per site) except at two sites. Larger numbers occurred at Ruth Island and Great Pond (55–95 pairs each), and birds have increased at the latter site. Crude breeding densities at all sites ranged from 0.2 to 23.5 pairs/ha, with the highest densities both years (> 1 pair/ha) restricted to the three largest tidally influenced wetlands, the three smallest cays, and the Buccaneer Hotel. White-crowned Pigeons nested in two habitats: (a) low in manglars (islets of one or more red mangroves Rhizophora mangle without solid land) over standing water in mangrove wetlands, and (b) higher over ground in a variety of nest-sites in littoral woodland, especially on cays. Roadside point-transect surveys throughout St. Croix during May of 2004 and 2005 confirmed that most White-crowned Pigeons occur in the general vicinity of confirmed breeding sites, despite their ability to fly long distances. Protection of vulnerable breeding sites such as Ruth Island where squabs are still poached, restoration of manglars as sheltered nest-sites in several tidally influenced wetlands, and expansion of foraging areas in littoral woodland near breeding sites should be conservation priorities for the White-crowned Pigeon on St. Croix. Their current breeding status suggests this species should be downlisted from territorially endangered to threatened in the United States Virgin Islands.

EXPLOITATION OF A SEASONAL RESOURCE BY NONBREEDING PLAIN AND WHITE-CROWNED PIGEONS: IMPLICATIONS FOR CONSERVATION OF TROPICAL DRY FORESTS

Columbids often exhibit irregular movement patterns in response to fruit abundance. We tested whether the abundance of nonbreeding Plain (Columba inornata) and White-crowned (C. leucocephala) pigeons was correlated with Thrinax parviflora fruit production in a dry forest in southeastern Jamaica. Monthly, from November to March, we counted the number of pigeons leaving the forest to roost in an adjacent mangrove swamp. Within two days of each roost count, we also counted all fruits on ten T. parviflora trees in the forest. Columbid and fruit counts showed similar patterns of temporal abundance, with increases from November to January and decreases from January to March. Peak (January) counts of White-crowned Pigeon, Plain Pigeon, and unidentified columbids were 129, 77, and 151, respectively. The peak Plain Pigeon count was approximately three times greater than the highest counts previously recorded for Jamaica. These data indicate that the Portland Ridge dry forest may provide a critical resource for the Plain Pigeon, perhaps at a time when fruit abundance is low on other parts of the island. Given the globally significant number of Plain Pigeons that use this site, protection from further development should be a priority.

Rainfall, Fruiting Phenology, and the Nesting Season of White-Crowned Pigeons in the Upper Florida Keys

AbstractWhite-crowned Pigeons (Columba leucocephala) varied their timing of breeding and nesting intensity in response to variation in production of the four most important fruit species in their breeding-season diet in the upper Florida Keys. From 1988 through 1990, we monitored fruit production year-round in five habitats in which pigeons foraged and monitored all pigeon nests along two transects on Middle Butternut Key. Annually, pigeon breeding was positively correlated with summer rains and with the peak in overall fruit production. However, within the breeding season, only the availability of Metopium toxiferum was positively correlated with rainfall and the number of new clutches initiated. Both the timing and magnitude of breeding varied annually. In 1988, when Metopium was more available, more pigeons nested, the nesting season started earlier and lasted longer, and a large peak in nesting occurred when Metopium fruit ripened. During 1989 and 1990, when the relative availability of Metopium was lower, fewer pigeons nested, the nesting season was shorter, and the seasonal peak in nesting associated with Metopium fruit was reduced or absent. Nesting patterns did not appear to vary with changes in the relative availability of other fruits. White-crowned Pigeons appear to prefer Metopium fruits to other species. Because pigeons do not supplement nestling diets with arthropods, but augment their diets with protein-rich crop milk, they may depend on lipid-rich fruits such as Metopium to provide the energy for breeding and crop-milk production. Metopium fruit production may be influenced by rainfall and climatic conditions, both of which may vary spatially within the range of White-crowned Pigeons in Florida. Evidence that pigeons shift foraging sites when Metopium availability varies emphasizes the need to preserve large tracts of seasonal deciduous forest in the Keys and to protect Metopium trees in suburban areas where they are removed because they cause contact dermatitis in humans.

Rainfall, Fruiting Phenology, and the Nesting Season of White-Crowned Pigeons in the Upper Florida Keys

Rainfall, Fruiting Phenology, and the Nesting Season of White-Crowned Pigeons in the Upper Florida Keys

RAINFALL, FRUITING PHENOLOGY, AND THE NESTING SEASON OF WHITE-CROWNED PIGEONS IN THE UPPER FLORIDA KEYS

Abstract White-crowned Pigeons (Columba leucocephala) varied their timing of breeding and nesting intensity in response to variation in production of the four most important fruit species in their breeding-season diet in the upper Florida Keys. From 1988 through 1990, we monitored fruit production year-round in five habitats in which pigeons foraged and monitored all pigeon nests along two transects on Middle Butternut Key. Annually, pigeon breeding was positively correlated with summer rains and with the peak in overall fruit production. However, within the breeding season, only the availability of Metopium toxiferum was positively correlated with rainfall and the number of new clutches initiated. Both the timing and magnitude of breeding varied annually. In 1988, when Metopium was more available, more pigeons nested, the nesting season started earlier and lasted longer, and a large peak in nesting occurred when Metopium fruit ripened. During 1989 and 1990, when the relative availability of Metopium was ...

Temporal Patterns in Diet of Nestling White-Crowned Pigeons: Implications for Conservation of Frugivorous Columbids

The timing and production of crop milk are important to the reproductive tactics of granivorous columbids, but little is known about crop-milk production in frugivorous columbids. We examined the diet of nestling White-crowned Pigeons (Columba leucocephala) and the relative contributions of crop milk and fruit during different stages of nestling development. The diet was dominated by five species of plants: Metopium toxiferum (poisonwood), Guapira discolor (blolly), Ficus citrifolia (shortleaf fig), F. aurea (strangler fig), and Erithalis fruticosa (black torch). Fruit of F. aurea and F. citrifolia dominated the diet during May and June. Fruit of M. toxiferum, which began to ripen in early July, dominated the diet through September. Guapira discolor was found in the diet throughout the nesting season and, overall, ranked as the second-most-important food. Erithalis fruticosa was found in small amounts in samples collected throughout the season. Crop milk remained an important component of the diet throughout the nestling period. As nestlings grew, fruit was added to the diet. At ages 0 to 2 days, the diet was entirely crop milk. The proportion of the diet composed of fruit increased from 10% on day 3 to 65% at day 15. These data suggest that the reproductive tactics of frugivorous pigeons may differ from those of granivorous pigeons. We speculate that frugivorous columbids may continue to supplement the diet of nestlings and fledglings with crop milk. Although this behavior may enhance growth rates and survival of individual young, it also may lengthen the interclutch interval. These findings emphasize the conservation importance of protecting large feeding areas to maintain populations of threatened and endangered frugivorous pigeons.

Postfledging Dispersal of White‐crowned Pigeons: Implications for Conservation of Deciduous Seasonal Forests in the Florida Keys

From 1988 to 1991, we studied the postfledging dispersal of 31 radio‐tagged White‐crowned Pigeons (Columba leucocephala) from three natal keys in Florida Bay. Immature birds dispersed from the natal keys at 26–45 days after batching, and most young dispersed more than 20 km during the first 10 days postdispersal. Dispersing birds flew either north to the Florida mainland or east to northeast to the mainline Florida Keys. On the mainland, immature birds fed nearly exclusively within Everglades National Park or an adjacent state wildlife management area. On the mainline keys, White‐crowned Pigeons selectively used 5.01–20 ha forest fragments (p < 0.10) during the first 72 hours postdispersal. After this period, dispersing birds showed no preference among fragment size classes but used deciduous seasonal forests more frequently than suburban habitat(p < 0.10). The spatial pattern of dispersal on the mainline keys suggests that, during the first 72 hours postdispersal. White‐crowned Pigeons are not able to reach northern Key Largo, where 69% of the deciduous seasonal forests are protected in state or federal ownership. Protection of large forest fragments, especially on southern Key Largo, should be a priority for maintaining populations of White‐crowned Pigeons. These forests provide a series of “stepping stones” that enable dispersing immature White‐crowned Pigeons to fly to more distant areas where habitat availability is less restricted. This species is threatened in Florida and may play an important role in maintaining plant species diversity in the seasonal deciduous forests of south Florida by dispersing seeds of at least 37 species of trees and shrubs. Protection of sufficient habitat to allow successful postfledging dispersal of this important seed disperser will also protect the ecosystem’s biodiversity.

Estimating White-Crowned Pigeon Population Size from Flight-Line Counts

The white-crowned pigeon (Columba leucocephala) is a threatened species in Florida, yet there are no population estimates nor are there methodologies available for estimating population size. During the 1991 nesting season, we developed a nondisruptive technique for estimating the nesting population of white-crowned pigeons in the upper Florida keys. Using radio telemetry and automatic cameras, we determined that breeding males returned to nesting keys later in the morning than do nonbreeding birds (P = 0.001). We studied the relationship between number of incoming birds and number of nests on 14 keys by conducting total nest counts and flight-line counts during 0810-1130 (mean arrival time for breeding males ±2 SD)

Distribution and Relative Abundance Patterns of Columbids in Puerto Rico

From July 1986 to January 1989 standardized call and sight counts were conducted to examine the distribution and relative abundance patterns of Plain Pigeons (Columba inornata), White-crowned Pigeons (C. leucocephala), Scaly-naped Pigeons (C. squamosa), Zenaida Doves (Zenaida aurita), White-winged Doves (Z. asiatica), Mourning Doves (Z. macroura), Common Ground-Doves (Columbina passerina), Ruddy Quail-Doves (Geotrygon montana), Key West Quail-Doves (G. chrysia), and Bridled Quail-Doves (G. mystacea) during the different seasons of the year in the dry, moist and wet zones of Puerto Rico. The relative abundance of all columbids peaked during the spring-summer period (March-August) in the life zones. The relative abundance of Zenaida Doves and Common Ground-Doves peaked during the spring-summer, but a second noticeable peak occurred during the fall (September-November) in the dry zone. The seasonal patterns of relative abundance were detectable at local as well as at regional scales of sampling, regardless of the observer involved and the counting technique applied. The detected patterns are not considered to be either the result of sampling error or of statistical artifacts. The seasonal patterns of relative abundance in the three major life zones probably represent the most general and repeatable aspect of the population dynamics of columbids in the island. Two components of the environment of columbids are considered of principal importance in determining their seasonal relative abundance in the life zones: (1) rainfall in the dry zone, and (2) fruiting phenology of key tree species in the moist and wet zones.

The White-Crowned Pigeon in Puerto Rico: Status, Distribution, and Movements

White-crowned pigeons (Columba leucocephala) were studied in Puerto Rico and offshore islands from December 1973 through September 1975. Additional observations were made from October 1975 to November 1976. White-crowned pigeons in Puerto Rico in the past century have declined to a few remnant populations. The decline resulted from destruction of habitat and over-shooting. In 1974 and 1975 an estimated 4,000 pigeons were located with largest breeding concentrations along the north and east coasts. Small populations occurred on Vieques (estimated 400 birds) and Culebra (estimated 300 birds) islands, while Mona Island had the largest population (estimated 6,000 birds) in Puerto Rican territory. J. WILDL. MANAGE. 43(2):402-413 The white-crowned pigeon is widely distributed throughout the Caribbean. It is found from southern Florida and the Florida Keys to the Bahamas, Greater Antilles, east and south to Antigua in the Lesser Antilles, and on the islands off the Caribbean coast of Central America from Yucatan to northwestern Panama (Bond 1956). The species has been reduced in numbers throughout much of its range, primarily due to habitat destruction and hunting, including squabbing. The white-crowned pigeon was formerly common in Puerto Rico (Taylor 1864, Gundlach 1878, Bowdish 1902) but has suffered a substantial decline. In 1911-12 Wetmore (1916a) found them in only a few localities as did Struthers (1927) in 1922. By 1931, Danforth considered the white-crown rare in Puerto Rico. Recently, however, McCandless (1958) and Leopold (1963) listed it as a fairly common, though local, resident in Puerto Rico. Despite growing international concern for the white-crowned pigeon, little has been reported on its biology. My purpose here is to present data on its past and present distribution, abundance, and movements in Puerto Rico. The U.S. Navy allowed me to conduct research on the Roosevelt Roads Naval Station, for which I am grateful. M. Hickman, U.S. Navy Ecology Coordinator, was particularly helpful in the field and in acquiring permits to work on the Station. L. Casasus, J. Gracia, J. Taapken, E. Litovich, and the late H. O'Neill assisted with interviewing and censusing. H. Raffaele generously allowed me to examine his field notes and showed me the Dorado Beach Hotel site. C. Braun, N. Snyder, and F. Wadsworth reviewed early drafts of this paper. My wife, Beth, has been involved in all phases of the work for which I am most grateful. This research was supported by Pittman-Robertson Federal Aid to Wildlife Restoration Projects W-8-17, 18, and 19.

Serotypes in Saccharomyces telluris: their relation to source of isolation.

Three serotypes have been characterized with three reference strains of Saccharomyces telluris and designated as A, B, and C. One reference strain of Torpulopsis bovina, the imperfect form of S. telluris, belonged to serotype B. Strains (141) of S. telluris isolated from four columbid species were serotyped. All 98 strains of this yeast isolated from Columba livia (feral pigeon) belonged to serotype B. Three other columbid species, C. leucocephala (white-crowned pigeon), C. fasciata (band-tailed pigeon), and Zenaidura macroura (mourning dove) harbored strains of serotype C only. Serotype A was not isolated from any of the avian species.

THE WHITE-CROWNED PIGEON A FRUIT-EATING PIGEON AS A HOST FOR Trichomonas gallinae

Trichomoniasis resulting from infection by Trichomonas gallinae was observed in 12 laboratory reared white-crowned pigeons (Columba leucocephala). A field survey of nestlings in the Florida Keys revealed a prevalence of 88% T. gallinae carriers but no evidence of trichomoniasis could be found among the wild birds.

Nesting Activities of the Red-Footed Booby in British Honduras

FROM 14 February to 9 May 1958 I conducted an intensive investigation of the breeding activities of the Red-footed Booby (Sula sula sula Linnaeus) on Half Moon Cay, 80 km east of Belize, British Honduras. The detailed results of the study appear in my thesis for the degree of Master of Science (Verner, thesis submitted 1959). Half Moon Cay (Figure 1) is a tiny coral island, 1.16 km in length, supporting mainly coconut palms (Cocos nucifera). The floor of the narrow eastern half of the cay has been cleared, and the palms there are planted in rows. On the western portion, exclusive of the booby colony, the palms are distributed naturally, the floor beneath being covered with lush, mat-forming herbs. Within the booby colony very few palms are present; instead, eight species of broadleaf trees form a nearly continuous overhead canopy from about six to 15 meters above the ground. The number of booby nests in each species of tree fairly well indicated the relative abundance of each species (Table 1). The floor of the colony is composed of coral stones, which permit potential humus to percolate away with the rains. As a result, there is little in the way of an herbaceous understory. The only undomesticated mammal on the cay is Rattus rattus. Ninetyeight species of birds were recorded during the course of the study. At least 77 of these were migratory forms, and, of these, only 17 were recorded regularly enough to indicate that they winter on or near the island. Two species, the Red-footed Booby and the Magnificent Frigate-bird (Fregata magnificens), were nesting at the time of the study; and probably both the White-crowned Pigeon (Columba leucocephala) and the Groove-billed Ani (Crotophaga sulcirostris) nested there later in the year. A number of small lizards and two larger ones, the False Iguana (Ctenosaura similis) and the Iguana (Iguarna iguana), were abundant. Nothing was observed to substantiate the many reports that these larger lizards harm nests, eggs, and young of the Red-footed Booby. The climate at Half Moon Cay is generally mild, although the high humidity makes even slight temperature differences more noticeable. Temperatures were recorded three times daily-morning, noon, and night-between 20 March and 7 May and the range was from 23?C (730F) to 320C (900F). With the exception of the early morning average of 26?C (790F) in March, all three daily averages for March,

Land Snails as Food of White-Crowned Pigeon

Land Snails as Food of White-Crowned Pigeon

The Physiology of the Formation of "Pigeon's Milk"

The Physiology of the Formation of "Pigeon's Milk"

“The Dispersion of Seeds and Plants”

IN support of the views expressed in Mr. D. Morris's interesting article on the above subject (NATURE, March 15, p. 466), I beg to be allowed to state the following facts. In the Island of Porto Rico, the Panicum barbinode, called there “malojilla,” has been cultivated for many years in the low humid lands, and it is a current opinion among farmers that it is reproduced by means of the animals feeding on it. Some fruit-bearing trees and shrubs, which are a favourite food for the wild Columba leucocephala and Columba corensis—among them the Solanum stramonifolium, the Bucida Buceras, the wild coffee, Coffea occidentalis, the palm-tree, Oredoxa regia—appear in some mountains and regions where they were formerly unknown, and there is no doubt that they have sprung from fruits and seeds transported by these pigeons. The Anona muricata (soursop), the Anona reticulata (custard apple), the Carica papaya (papaw tree), whose hard seeds are sometimes uninjured by the processes of mastication and digestion, are also believed to be planted accidentally by birds, and sometimes by hogs, horses, and other Mammalia. They grow all about in pastures where these animals are fed. The statement made about the orange-tree in Jamaica also holds good for Porto Rico. Very few orange-trees were planted in the interior of the country, and the tree is now wild in all that zone by the agency of birds in great part. There is no doubt, as Mr. Morris says, that birds and cattle have been the means of distributing plants all over the island.