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Geology topics

J. W. Wiley

Publications and source records attributed to J. W. Wiley.

At least 19 recordsLinked to original sources
USGS2010

Population size of Cuban Parrots Amazona leucocephala and Sandhill Cranes Grus canadensis and community involvement in their conservation in northern Isla de la Juventud, Cuba

The Cuban Sandhill Crane Grus canadensis nesiotes and Cuban Parrot Amazona leucocephala palmarum are considered endangered species in Cuba and the Isla de la Juventud (formerly Isla de Pinos). Coincident with a public education campaign, a population survey for these species was conducted in the northern part of the Isla de la Juventud on 17 December 1995, from o6hoo to 10hoo. Residents from throughout the island participated, manning 98 stations, with 1–4 observers per station. Parrots were observed at 60 (61.2%) of the stations with a total of 1320, maximum (without correction for duplicate observations), and 1100, minimum (corrected), individuals counted. Sandhill cranes were sighted at 38 (38.8%) of the stations, with a total of 115 individuals. Cranes and parrots co-occurred at 20 (20.4%) of the stations.

Isla de la Juventud↗
USGS2009

The reintroduction of the Andean condor into Colombia, South America: 1989-1991

From 1989 to 1991,22 captive-reared Andean condors Vultur gryphus were released into three protected areas in the Andes of Colombia, South America. The goals of this reintroduction programme were to re-establish populations of these birds in protected habitat where the species had been extirpated, and to train local biologists in the conservation techniques necessary to recover their native condor. All birds were hatched, reared and released according to the protocols established by the US Fish and Wildlife Service and the California Department of Fish and Game for the California condor Gymnogyps californianus. At the time of release, the birds ranged in age from 11 to 26 months. Each bird was fitted with individually numbered wing tags and wing-mounted radio transmitters. Of the 22 released animals, 19 currently survive – a substantial increase to the wild population in Colombia, which had been estimated by Colombian biologists to number only 20 individuals.

Oryx↗
USGS2008

Egg rejection behavior in a population exposed to parasitism: Village Weavers on Hispaniola

In contrast to African Village Weavers (Ploceus cucullatus) that are parasitized by Diederik Cuckoos (Chrysococcyx caprius), introduced weavers on Hispaniola existed without parasitism for at least 2 centuries until the arrival of the Shiny Cowbird (Molothrus bonariensis) in the 1970s. Cruz and Wiley (1989) found that Hispaniolan weavers had a lower rejection rate of foreign eggs than African populations. Subsequently, Robert and Sorci (1999) and Lahti (2005, 2006) found that acceptance of dissimilar eggs is not characteristic of the species throughout its Hispaniolan range. In 1999-2002, we studied egg rejection in Hispaniolan weavers on a broad regional scale. Rejection increased as experimental eggs became increasingly different from the host eggs. Rejection rates for mimetic eggs, different color eggs, different-spotting eggs, and cowbird eggs was 23.2%, 33.3%, 61.5%, and 85.3%, respectively, with higher rejection of cowbird eggs in areas where cowbirds were observed. Although rejection is likely to have a genetic component, the differences could be due to phenotypic plasticity. Plasticity in egg rejection may be expected, given the potential cost of rejection and the spatiotemporal distribution of cowbirds. Thus, egg rejection has not necessarily decreased in Hispaniolan weavers, but it may act in a plastic manner, increasing where cowbirds are present. ?? The Author 2008. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved.

Behavioral Ecology↗
USGS2007

Effects of experimental egg composition on rejection by Village Weavers (Ploceus cucullatus)

We experimentally parasitized nests of the Village Weaver (Ploceus cucullatus) in Hispaniola using real and artificial eggs made from wood and modeling clay. Artificial eggs were similar in size and shape to real weaver eggs and were coated with acrylic paint and glazed. Real eggs were actual weaver eggs taken from Village Weaver nests. Experimental parasitic eggs (1) mimicked natural weaver eggs, (2) differed in color only, (3) differed in spotting only, or (4) mimicked Shiny Cowbird (Molothrus bonariensis) egg color and spotting pattern. Parasitized nests were checked after 2-6 days. Real eggs were ejected from weaver nests with increasing frequency as they became less similar to the eggs in the nest with cowbirds eggs having the highest rejection (81%). However, for artificial egg types there were no significant within-composition differences in patterns of rejection. Clay eggs were usually ejected from the nests, whereas nests containing wood eggs often ended empty, or with only the artificial egg remaining in the nest. These patterns may reflect the differential ability of weavers to recognize and remove foreign eggs of different compositions from their nests. Researchers undertaking egg-rejection experiments should use real eggs either in addition or in place of artificial eggs to assess the cost of rejection and the coevolutionary relationships between parasite and host.

Wilson Journal of Ornithology↗
USGS2005

Taxonomic status and biology of the Cuban blackhawk, Buteogallus anthracinus gundlachii (AVES: Accipitridae)

We reevaluate the taxonomic status of the Cuban population of the Common Black-Hawk (Buteogallus anthracinus) based on our examination of additional specimens, nests, eggs, and voice data. Buteogallus a. gundlachii is smaller than mainland populations of anthracinus and differs from mainland birds in plumage coloration and pattern. The common (alarm) call of gundlachii is a series of three or four notes, differing from that of mainland anthracinus, whose call consists of 9-24 notes. In the Isla de Pinos, Cuba, we observed gundlachii eating two species of land crabs (71.4%), centipedes (7.1%), lizards (10.7%), mammals (7.1%), and a bird (3.6%). We consider Buteogallus gundlachii Cabanis 1854 (1855), the Cuban Black-Hawk, to be a full species, endemic to Cuba, Isla de Pinos, and many of the cays of the Cuban Archipelago. ?? 2005 The Raptor Research Foundation, Inc.

Journal of Raptor Research↗
USGS2003

Histories of Puerto Rican parrot nests in the Caribbean National Forest/Luquillo Experimental Forest, 1973-2000

This publication summarizes the histories of all known Puerto Rican parrot nests in the Caribbean National Forest/Luquillo Experimental Forest from 1973 through 2000. Included for each nest, when known, are the identifies of the pair, clutch size, known fertile and infertile eggs, number of eggs that hatched, number of chicks that survived, sources of mortality, fostering (source, destination. or both), number of young fledged from the pair and from the nest, and percentage of days the nest was guarded. This information is useful for detecting and assessing potential changes in reproductive output and nest threats and is fundamental for understanding some of the demographic and genetic factors influencing the wild parrot population.

Report↗
USGS2003

Habitat association, size, stomach contents, and reproductive condition of Puerto Rican boas (Epicrates inornatus)

The Puerto Rican boa occurs in a variety of habitats, including wet montane forest, lowland wet forest, mangrove forest, wet limestone karst, and offshore cays, and from sea level to 480 m. Mean SVL of 49 encountered boas (live and road-killed) was 136.9 ?? 35.1 (range = 38.8-205 cm), with a mean mass of 952.1 ?? 349.0 g (n = 47; range = 140-1662 g). Prey in digestive tracts (n = 29) included remains of black rats, house mice, three species of anoles, bats, common ground-doves, domestic fowl chicks, and invertebrates. Females were in reproductive condition in late April through mid-August and had an average brood size of 21.8 ?? 6.0 (n = 9, range = 13-30 ).

Caribbean Journal of Science↗
USGS2002

Limitations of captive breeding in endangered species recovery

The use of captive breeding in species recovery has grown enormously in recent years, but without a concurrent growth in appreciation of its limitations. Problems with (1) establishing self-sufficient captive populations, (2) poor success in reintroductions, (3) high costs, (4) domestication, (5) preemption of other recovery techniques, (6) disease outbreaks, and (7) maintaining administrative continuity have all been significant. The technique has often been invoked prematurely and should not normally be employed before a careful field evaluation of costs and benefits of all conservation alternatives has been accomplished and a determination made that captive breeding is essential for species survival. Merely demonstrating that a species’ population is declining or has fallen below what may be a minimum viable size does not constitute enough analysis to justify captive breeding as a recovery measure. Captive breeding should be viewed as a last resort in species recovery and not a prophylactic or long-term solution because of the inexorable genetic and phenotypic changes that occur in captive environments. Captive breeding can play a crucial role in recovery of some species for which effective alternatives are unavailable in the short term. However, it should not displace habitat and ecosystem protection nor should it be invoked in the absence of comprehensive efforts to maintain or restore populations in wild habitats. Zoological institutions with captive breeding programs should operate under carefully defined conditions of disease prevention and genetic/behavioral management. More important, these institutions should help preserve biodiversity through their capacities for public education, professional training, research, and support of in situ conservation efforts.

Conservation Biology↗
USGS2002

Nest poaching in Neotropical parrots

Although the poaching of nestlings for the pet trade is thought to contribute to the decline of many species of parrots, its effects have been poorly demonstrated. We calculated rates of mortality due to nest poaching in 23 studies of Neotropical parrots, representing 4024 nesting attempts in 21 species and 14 countries. We also examined how poaching rates vary with geographic region, presence of active protection programs, conservation status and economic value of a species, and passage of the U.S. Wild Bird Conservation Act. The average poaching rate across all studies was 30% of all nests observed. Thirteen studies reported poaching rates of ≥20%, and four reported rates openface> 70%. Only six studies documented no nest poaching. Of these, four were conducted on islands in the Caribbean region, which had significantly lower poaching rates than the mainland Neotropics. The other two studies that showed no poaching were conducted on the two species with the lowest economic value in our sample ( U.S. retail price). In four studies that allowed direct comparison between poaching at sites with active nest protection versus that at unprotected sites, poaching rates were significantly lower at protected sites, suggesting that active protection efforts can be effective in reducing nest poaching. In those studies conducted both before and after the passage of the U.S. Wild Bird Conservation Act, poaching rates were found to be significantly lower following its enactment than in the period before. This result supports the hypothesis that the legal and illegal parrot trades are positively related, rather than inversely related as has been suggested by avicultural interests. Overall, our study indicates that poaching of parrot nestlings for economic gain is a widespread and biologically significant source of nest mortality in Neotropical parrots.

Conservation Biology↗
USGS1998

Breeding-season food habits of burrowing owls (Athene cunicularia) in southwestern Dominican Republic

Diet data from 20 Burrowing Owl (Athene cunicularia) nests were collected in southwestern Dominican Republic in 1976, 1982, and 1996. Invertebrates (53.3%) comprised the most numerous prey items (N = 396) delivered to nests by adult owls, but vertebrates (46.7%) were much better represented than in other studies of Burrowing Owl diet. Among vertebrates, birds (28.3% of all items) and reptiles (14.9%) were most important, whereas mammals (1.0%) and amphibians (2.5%) were less commonly delivered to nests. Vertebrates, however, comprised more than twice (69.2%) of the total biomass as invertebrates (30.8%), with birds (50.4%) and reptiles (12.8%) the most important of the vertebrate prey classes. A positive relationship was observed between bird species abundance and number of individuals taken as prey by Burrowing Owls.

Journal of Raptor Research↗
USGS1993

Natural range expansion and local extirpation of an exotic psittacine--an unsuccessful colonization attempt

The Brown-throated Parakeet Aratinga pertinax is native to Panama, northern South America, and the islands off the northern coast of Venezuela. It is widely believed that the parakeet was introduced to St. Thomas, Virgin Islands, from Curacao before the mid-19th century, although no records exist as to when and how this may have occurred. The parakeet was not recorded from Vieques or Culebra islands or mainland Puerto Rico before 1975. However, in that year A. pertinax underwent an apparent natural range expansion from St. Thomas into each of these sites. The 5 birds in the eastern Puerto Rico population made 5 breeding attempts and fledged 11 young since their discovery in April1975. That population grew to a maximum size of 10 birds in June 1979. However there was only 1 bird left by July 1980, and the population no longer existed at the beginning of what would have been the 1982 breeding season. The populations on Culebra and Vieques islands were apparently extirpated by 1976. Losses in the eastern Puerto Rico population were low during the first four years of colonization, when reproduction was adequate and the mortality was low. However, between 1978 and the time of population disappearance in 1982, the expected extirpation was 0.999. Habitat use, general behavior, breeding biology, competitors and predators of the colonizing population in eastern Puerto Rico are described. Biogeographic, evolutionary, and conservation implications of these observations are discussed.

Ornitologia Neotropical↗
USGS1991

Conservation of the yellow-shouldered blackbird Agelaius xanthomus, an endagered West Indian species

The yellow-shouldered blackbird Agelaius xanthomus , endemic to Puerto Rico and Mona Island, is endangered, mainly because of brood parasitism by the shiny cowbird Molothrus bonariensis , which reached Puerto Rico at least 30 years ago. The yellow-shouldered blackbird populations have since declined, about 770–1200 remaining (470–900 on Mona Island) by 1982–1986 compared to a population of about 2400 in 1975. Nearly all nests of blackbirds in most of its habitats are parasitized by cowbirds. This significantly reduces nesting success, but blackbirds have evolved no defenses against brood parasitism. Removal of cowbirds from the yellow-shouldered blackbird nesting grounds, modeled after similar programmes for the brown-headed cowbird Molothrus ater on Kirtland's warbler Dendroica kirtlandii nesting areas, significantly increased blackbird production. Blackbirds readily accept nest boxes, and breeding populations can be established in otherwise unusable sites and can be concentrated in mangrove habitats, were they are more easily protected by cowbird removal. Furthermore, yellow-shouldered blackbird pairs using cavities, including nest boxes, fledged more young per nest than pairs using open nests.

Boquerón Commonwealth Forest, Roosevelt Roads Nava↗
USGS1991

Ecology and behavior of the zenaida dove

Data are summarized from a 10 year study of the Zenaida Dove (Zenaida aurita) in Puerto Rico and its offshore islands. The dove displays sexual size dimorphism, with males generally larger than females: Most activities (feeding, courtship, fighting) occurred in mornings and afternoons, whereas loafing and maintenance activities were more prevalent at mid-day. I recorded 77 plant species used as food by Zenaida Doves in Puerto Rico. Major food species uncluded Scleria lithosperma, Argemone mexicana, Croton rigidus, Phyllanthus amarus, Cordia angustifolia, Zanthoxylum martinicense, Euphorbia heterophylla, and several species of legumes. Zenaida Doves have two major vocalizations: the 'Coo', or Advertisement Call, given in assertive and sexual contexts, and the Nest Call, primarily used at or near the nest. Doves nested in a wide variety of habitats, including forest edge, mangrove forest, dry scrub, and mixed agriculture-urban areas. Nests were generally placed in trees, but doves nested on the ground where certain terrestrial predators were absent. Nests were found in all months of the year, although a breeding peak occurred from March through Mayor July. Doves replaced clutches when nests were destroyed, and recycled up to four times in a season. Males selected nest sites and initiated building. Eggs (2) were laid on alternate days, beginning about two days after the nest was completed. Incubation and nestling stages averaged 13.9 :t 0.5 [SE] and 14.3 :t 0.6 days. The male attended the nest from mid-morning (X = 08:59 hr) through mid-afternoon (x = 16:53), then the female took over incubation and brooding duties for the night. Nests were continuously covered from the laying of the first egg through day seven of the nestling stage. Thereafter, adult attendance dropped steadily until day 14, when they carne to the nest only for chick feedings. Chicks (days 0-15) showed a mean daily weight gain of 18.3% and attained a fledging weight of about 120g (81% of adult weight). The mean daily growth (culmen, tarsometatarsus, ulna) was 6.8% (range = 4.0-9.8% daily). Dove productivity varied among and within study areas over the 10 years. Mean number of chicks hatched per nest that held eggs ranged from 0.3 to 1.6 for 3 study areas. Mean number fledged per nest ranged from 0.3 to 1.4. Productivity was lowest in the dry southwestern Puerto Rico study area (Susua and Guanica forests; x = 0.7 chicks fledged per nest) and was highest for the lower montane mixed agriculture/urban area (Cidra; 1.2). Populations nesting in scrub and mangrove forests (Roosevelt Roads Naval Station) fledged an average of 0.9 chicks/nest. Nest success followed a similar geographic pattern: southwestern Puerto Rico -40.9% of nests with eggs were successful, Cidra -62.6%, and Roosevelt Roads -52.0%. The most important sources of dove egg and chick loss were Pearly-eyed Thrashers (Margarops fuscatus -49% of losses) and roof rats (Rattus rattus -16%).

Ornitologia Neotropical↗