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At least 163 records · Page 9Linked to original sources

The haunting raptor: Yellowstone’s golden eagles

For many who live in North America, when picturing an eagle, the image of a large magnificent bird with a distinct white head and tail comes to mind. Rightfully, the bald eagle has garnered much attention as a national symbol of the United States (US), nearly brought to extinction from widespread organochlorine pesticide use (e.g., DDT, dichloro- diphenyl- trichloroethane; Anderson 1972, Baril et al. 2015). Previously listed at the federal level as an endangered species downlisted in 1985 and removed from the list in 2007, the bald eagle has been studied extensively across its range, including 38 years of monitoring in Yellowstone National Park (Yellowstone; YNP). However, a second eagle species, equally magnificent and widely distributed throughout Earth’s northern hemisphere, also resides in YNP but has been relatively neglected in terms of scientific study. Unlike the bald eagle, the golden eagle does not have such conspicuous characteristics - instead it is dark brown throughout with brilliant golden feathers on the back of its head and neck, and subtle gray barring in the tail (Fig. 11.1). The golden eagle is, however, an iconic apex predator tied to human culture through spiritual beliefs, reverence, and, like many other predators, persecution as a result of misunderstanding.

Book chapter

Sea‐level rise, habitat loss, and potential extirpation of a salt marsh specialist bird in urbanized landscapes

Sea‐level rise (SLR) impacts on intertidal habitat depend on coastal topology, accretion, and constraints from surrounding development. Such habitat changes might affect species like Belding's savannah sparrows ( Passerculus sandwichensis beldingi ; BSSP), which live in high‐elevation salt marsh in the Southern California Bight. To predict how BSSP habitat might change under various SLR scenarios, we first constructed a suitability model by matching bird observations with elevation. We then mapped current BSSP breeding and foraging habitat at six estuarine sites by applying the elevation‐suitability model to digital elevation models. To estimate changes in digital elevation models under different SLR scenarios, we used a site‐specific, one‐dimensional elevation model (wetland accretion rate model of ecosystem resilience). We then applied our elevation‐suitability model to the projected digital elevation models. The resulting maps suggest that suitable breeding and foraging habitat could decline as increased inundation converts middle‐ and high‐elevation suitable habitat to mudflat and subtidal zones. As a result, the highest SLR scenario predicted that no suitable breeding or foraging habitat would remain at any site by 2100 and 2110. Removing development constraints to facilitate landward migration of high salt marsh, or redistributing dredge spoils to replace submerged habitat, might create future high salt marsh habitat, thereby reducing extirpation risk for BSSP in southern California.

Ecology and Evolution

Variation in maternal effects and embryonic development rates among passerine species

Embryonic development rates are reflected by the length of incubation period in birds, and these vary substantially among species within and among geographical regions. The incubation periods are consistently shorter in North America (Arizona study site) than in tropical (Venezuela) and subtropical (Argentina) South America based on the study of 83 passerine species in 17 clades. Parents, mothers in particular, may influence incubation periods and resulting offspring quality through proximate pathways, while variation in maternal strategies among species can result from selection by adult and offspring mortality. Parents of long-lived species, as is common in the tropics and subtropics, may be under selection to minimize costs to themselves during incubation. Indeed, time spent incubating is often lower in the tropical and subtropical species than the related north temperate species, causing cooler average egg temperatures in the southern regions. Decreased egg temperatures result in longer incubation periods and reflect a cost imposed on offspring by parents because energy cost to the embryo and risk of offspring predation are both increased. Mothers may adjust egg size and constituents as a means to partially offset such costs. For example, reduced androgen concentrations in egg yolks may slow development rates, but may enhance offspring quality through physiological trade-offs that may be particularly beneficial in longer-lived species, as in the tropics and subtropics. We provide initial data to show that yolks of tropical birds contain substantially lower concentrations of growth-promoting androgens than north temperate relatives. Thus, maternal (and parental) effects on embryonic development rates may include contrasting and complementary proximate influences on offspring quality and deserve further field study among species. ?? 2007 The Royal Society.

Philosophical Transactions of the Royal Society B:

Avian community responses to juniper woodland structure and thinning treatments on the Colorado Plateau

Federal land managers are increasingly implementing fuels-reduction treatments throughout the western United States with objectives of ecological restoration and fire hazard reduction in pinyon-juniper (Pinus spp.-Juniperus spp.) woodlands. The pinyon-juniper woodland ecosystem complex is highly variable across the western landscape, as is bird community composition. We investigated relations between breeding birds and vegetation characteristics in modified pinyon-juniper woodlands at three sites (BLM, USFS, NPS) on the Colorado Plateau. During the breeding seasons of 2005 and 2006, we surveyed birds and measured vegetation in 74 study plots. These plots were each 3.1 hectares (ha; 7.6 acres), located across the range of natural variation, with 41 control sites and 33 plots in areas previously thinned by hand-cutting or chaining. We found that relations of avian pinyon-juniper specialists and priority species to vegetation characteristics were generally in agreement with the findings of previous studies and known nesting and feeding habits of those birds. Relatively high density of pinyon pines was important to species richness and abundance in 6 of 14 species. Abundance of all species was related to treatment method, and we found no difference in bird communities at chaining and hand-cut sites. We also studied responses of breeding birds to mechanical reduction of pinyon-juniper woodlands scattered across sagebrush steppe in 11 control and 9 treatment plots at Grand Staircase-Escalante National Monument, Utah, in 2005 and 2006. We surveyed birds in 3.1-ha (7.6-acre) plots during the breeding season before and following treatment. Thinning in April 2006 removed a mean of 92 percent (standard error = 6.4 percent) of the live trees from treatment plots. Two of 14 species, Gray Vireo (Vireo vicinior) and Brown-headed Cowbird (Molothrus ater), were not detected after thinning. Shrub-nesting birds, including sagebrush specialist Brewer's Sparrow (Spizella breweri), increased in relative abundance in treatment areas compared to controls. However, some species may exhibit a time lag in response, and further changes in community composition and abundance could result. Our findings lend support to the concept that multiple small-scale fuels-reduction treatments, applied over the landscape, may provide the variety of successional stages needed to support a full assemblage of avian species in pinyon-juniper woodlands on the Colorado Plateau. Limiting scale and increasing precision of fuels-reduction projects in pinyon-juniper vegetation communities may maximize the benefits of management to both the pinyon-juniper and sagebrush steppe avian communities. We conclude that small-scale fuels-reduction treatments can benefit many bird species while reducing fire risk and restoring an ecological balance.

Open-File Report

The epidemiology of avian pox and interaction with avian malaria in Hawaiian forest birds

Despite the purported role of avian pox ( Avipoxvirus spp.) in the decline of endemic Hawaiian birds, few studies have been conducted on the dynamics of this disease, its impact on free‐living avian populations, or its interactions with avian malaria ( Plasmodium relictum ). We conducted four longitudinal studies of 3–7 yr in length and used generalized linear models to evaluate cross‐sectional prevalence of active pox infection and individuals with healed deformities that had recovered from pox. Our goal was to understand how species, season, elevation, malaria infection, and other biological characteristics influenced pox infection in ʻApapane, Hawaiʻi ʻAmakihi, ʻIʻiwi, and Japanese White‐eye across low‐, mid‐, and high‐elevation forests on the island of Hawaiʻi. We also used multi‐state capture‐recapture (longitudinal) models to estimate pox infection rates, recovery rates, and potential pox‐related mortality. Pox infection rates were typically highest in low‐elevation forests, followed by mid‐elevation forests, and lowest in high‐elevation forests. We also found seasonal changes in pox prevalence throughout the annual cycle; typically increasing from spring through summer, peaking in fall, and declining in winter. These seasonal changes occurred in low‐ and mid‐elevation forests, but not in high elevations where pox infection was low. Seasonal and elevation patterns of pox infection are like those for avian malaria, strongly implicating mosquito vectors, rather than other biting arthropods or contact transmission, as the primary source of transmitting both diseases. Most native Hawaiian birds recovered from pox infection within 6 months; frequently without permanent lesions. Contrary to our expectations, we found no direct evidence that pox is a substantial mortality factor in any of the three native bird species we studied. Birds with chronic malaria infection were more likely to have both active pox infection and healed pox lesions suggesting a synergistic interaction that may influence the evolution of pox virulence. Because pox infection can be assessed visually, and birds have a high recovery rate, this disease may be a sensitive indicator of the seasonal and annual risk of transmission of malaria in Hawaiʻi.

Ecological Monographs

Chlamydiosis

Chlamydiosis refers to an infection with organisms of the genus Chlamydia sp., which are bacteria that live within animal cells. Chlamydia psittaci is the species generally associated with this disease in birds. The severity of the disease differs by the strain of C. psittaci and the susceptibility of different species of birds. As a result, chlamydiosis may range from an inapparent infection to a severe disease with high mortality. The organism is excreted in the feces and nasal discharges of infected birds and can remain infective for several months. Infection commonly occurs from inhaling the bacteria in airborne particles from feces or respiratory exudates. Because of the organism’s resistance to drying, infected bird feces at roosts are especially hazardous.

Information and Technology Report

Biological diversity of created forested wetlands in comparison to reference forested wetlands in the Bay watershed

Amphibians, reptiles, birds, and mammals were surveyed at six created forested wetlands in central Maryland and at six adjacent reference forested wetlands during 1993-1996 to determine comparative biological diversity of these habitats. Amphibians and reptiles were caught in pitfall and funnel traps associated with 15.4m (50 ft) drift fences. Birds were surveyed with a complete count while walking through each area. Mammals were surveyed by capture in live traps. More species and total individuals of amphibians were caught on the reference wetlands than on the created wetlands. The red-backed salamander (Plethodon cinereus), the four-toed salamander (Hemidactylium scutatum), the eastern spadefoot (Scaphiopus holbrooki), and the wood frog (Rana sylvatica) were captured on the reference wetlands, but not on the created sites. The wood frog was captured at all reference sites and may represent the best amphibian species to characterize a forested wetland. Reptiles were not caught in sufficient numbers to warrant comparisons. Ninety-two bird species were recorded on created sites and 55 bird species on the reference sites. Bird species on the created sites represented those typically found in nonforested habitats. Mammal species were similar on both sites, but overall the reference sites had three times the number caught on created sites. The meadow vole (Microtus pennsylvanicus) was the dominant species captured on created sites, and the white-footed mouse (Peromyscus leucopus) was the dominant species on reference sites, with little habitat overlap for these two species. Although species richness and total number of animals were high for created forested wetlands, these survey results show major differences from species expected for a forested wetland. The created forested wetlands appear to provide good habitat for wildlife, but are probably not providing the full functions and values of the forested wetlands that they were constructed to replace.

Book chapter

Desert fires fueled by native annual forbs: effects of fire on communities of plants and birds in the lower Sonoran Desert of Arizona

In 2005, fire ignited by humans swept from Yuma Proving Grounds into Kofa National Wildlife Refuge, Arizona, burning ca. 9,255 ha of Wilderness Area. Fuels were predominantly the native forb Plantago ovata . Large fires at low elevations were rare in the 19th and 20th centuries, and fires fueled by native vegetation are undocumented in the southwestern deserts. We estimated the area damaged by fire using Moderate Resolution Imaging Spectroradiometer and Normalized Difference Vegetation Index, which are more accurate and reduce subjectivity of aerial surveys of perimeters of fires. Assemblages of upland and xeroriparian plants lost 91 and 81% of live cover, respectively, in fires. The trees Olneya tesota and Cercidium had high amounts of top-kill. King Valley was an important xeroriparian corridor for birds. Species richness of birds decreased significantly following the fire. Numbers of breeding birds were lower in burned areas of King Valley 3 years post-fire, compared to numbers in nearby but unburned Alamo Wash. Although birds function within a large geographic scale, the extent of this burn still influenced the relative abundance of local species of breeding birds. This suggests that breeding birds respond to conditions of localized burns and slow recovery of vegetation contributes to continued lower numbers of birds in the burned sites in King Valley.

Arizona

Direct fitness benefits and kinship of social foraging groups in an Old World tropical babbler

Molecular studies have revealed that social groups composed mainly of nonrelatives may be widespread in group-living vertebrates, but the benefits favoring such sociality are not well understood. In the Old World, birds often form conspecific foraging groups that are maintained year-round and offspring usually disperse to other social groups. We tested the hypothesis that nonbreeding group members are largely unrelated and gain direct fitness benefits through breeding opportunities (males) and brood parasitism (females) in the tropical gray-throated babbler, Stachyris nigriceps , in Malaysian Borneo. Babblers foraged in social groups containing one or more breeding pairs (median = 8 group members of equal sex ratio), but group members rarely assisted with breeding (9% of 67 breeding pairs had a third helper; exhibiting facultative cooperative breeding). Although 20% of 266 group member dyads were first-order relatives of one or both members of the breeding pairs, 80% were unrelated. Male group members gained direct fitness benefits through extrapair and extra-group paternity (25% of 73 offspring), which was independent of their relatedness to the breeding pair and increased with decreasing group size. In contrast, females did not gain direct fitness benefits through brood parasitism. The low levels of relatedness and helping in social groups suggest that most group members do not gain indirect fitness benefits by helping to raise unrelated offspring. These findings highlight the importance of examining benefits of sociality for unrelated individuals that largely do not help and broaden the direct fitness benefits of group foraging beyond assumed survival benefits.

Behavioral Ecology

Comparison of breeding bird and vegetation communities in primary and secondary forests of Great Smoky Mountains National Park

We compared breeding bird communities and vegetation characteristics at paired point locations in primary (undisturbed) and mature secondary forest (70-100 years old) sites in Great Smoky Mountains National Park, USA to understand how sites logged prior to creation of the park compare to undisturbed sites following 70 years of protection from human disturbance. We found that bird and vegetation communities are currently similar, but retain some differences in species composition. Rank abundance curves for primary and secondary forest bird communities showed very similar patterns of species dominance. Species composition was also similar on the two sites which shared 24 of the 25 most frequently recorded species. Nonetheless, comparisons of density estimates derived from distance sampling showed three bird species were more abundant on primary forest sites and that one bird species was significantly more abundant on secondary forest sites. Notably, comparisons based on raw counts (unadjusted for potential differences in detectability) produced somewhat different results. Analyses of vegetation samples for the paired sites also showed relative similarity, but with some differences between primary and secondary forests. Primary forest sites had more large trees (trees greater than 50 cm diameter at breast height) and late successional species. Primary forest sites had a denser tall shrub layer while secondary forest sites had a denser canopy layer. Nonetheless, tree species richness, basal area of live trees and number of standing snags did not differ between primary and secondary forest sites. Results indicate that breeding bird communities on sites within the park that were logged commercially 70 years ago are currently quite similar to bird communities on sites with no history of human disturbance. Similarities between the bird communities on previously disturbed and undisturbed sites in Great Smoky Mountains National Park may exceed those on more fragmented landscapes because large patches of primary forest, adjacent to commercially logged sites, remained in the park when it was established in 1935. These patches of primary forest may have served as source areas for commercially logged sites.

North Carolina, Tennessee

Ecotoxicological damage from zinc smelting at Palmerton, Pennsylvania

The two zinc smelters at Palmerton, PA emitted huge amounts of contaminants ( 260,000 t of Zn, 3,300 t of Cd, 6,800 t of Pb) to the air and severely damaged the forest on Blue Mountain. The high Zn concentrations in soil killed tree seedlings by inhibiting root elongation. The result was a forest with too few young trees. When natural stresses such as fire challenged the forest, the forest failed to regenerate, and the exposed soil eroded down the steep slopes. Tree species that could sprout were favored over those that developed from seeds. As a result of high zinc concentrations, the lichen and moss communities were depauperate for at least 20 km along Blue Mountain. The denuded areas are in the process of being reclaimed with the addition of a mixture of fly ash and sewage sludge, which is seeded with grasses tolerant to the harsh conditions. In preliminary experiments, the fly ash and sewage sludge mixture was stable, despite the steepness of the slopes of the reclaimed sites on Blue Mountain. Zinc emissions reduced the decomposition rate of plant material on Blue Mountain. The partially decomposed litter, in particular, accumulated on the surface of the mineral soil. The populations of both microorganisms and arthropods were greatly reduced in soils near the smelters. Samples of litter collected from sites spanning 30 km were toxic to woodlice, and Zn was shown to be the toxic factor. A white-tailed deer examined had a very high renal Zn concentration and an articular lesion in one of its hind legs that closely resembled the lesions reported in Zn-poisoned horses. Zinc concentrations were regulated in wildlife tissues and were not reliable indicators of exposure, except in extreme cases. Two songbirds, a shrew, and several rabbits contained Pb concentrations that were suggested to be toxic. Shrews and ground-feeding songbirds accumulated relatively high concentrations of Pb. Exposure to Pb seemed to be related to the amount of soil that an animal ingests. Some white-tailed deer and cottontails had renal Cd concentrations near 600 ppm w.w., which is associated with renal damage in other mammals. The accumulation of Cd was greatest in wildlife that lived longest. The destruction of the habitat for wildlife on Blue Mountain decreased wildlife populations. Populations of insectivorous birds, however, were depressed well beyond the area of obvious damage to the forest. Forest-floor salamanders were completely absent from study sites spanning 18 km along Blue Mountain. Actual reductions in wildlife populations were much greater than would have been predicted from habitat suitability models alone.

Book chapter

Field evaluation of lead effects on Canada geese and mallards in the Coeur d'Alene River Basin, Idaho

Hatch year (HY) mallards ( Anas platyrhynchos ) in the Coeur d'Alene (CDA) River Basin had higher concentrations of lead in their blood than HY Western Canada geese ( Branta canadensis moffitti ) (geometric means 0.98 versus 0.28 μg/g, wet weight). The pattern for adults of both species was similar, although geometric means (1.77 versus 0.41 μg/g) were higher than in HY birds. HY mallards captured in the CDA River Basin in 1987 contained significantly lower lead concentrations in their blood than in 1994–95 (0.36 versus 0.98 μg/g); however, some very young mallards were sampled in 1987, and concentrations in adults were not significantly different in 1987, 1994, or 1995 (1.52, 2.07, 1.55 μg/g, respectively). Both species in the CDA River Basin in 1994–95 showed significantly reduced red blood cell delta-aminolevulinic acid dehydratase (ALAD) activity compared to the reference areas: Canada geese (HY −65.4 to −86.0%, adults −82.3%), and mallards (HY −90.7 to −95.5%, adults −94.1%). Canada goose goslings were divided into size classes, and the two smaller classes from the CDA River Basin had significantly elevated free erythrocyte protoporphyrin (protoporphyrin) levels compared to the reference area (15.2× and 6.9×). HY and adult mallards both had significantly elevated protoporphyrin (5.9× and 7.5×). Recognizing that interspecific differences exist in response and sensitivity to lead, it appears (at least for hemoglobin and hematocrit) that Canada geese were more sensitive to lead than mallards, i.e ., adverse hematologic effects occur at lower blood lead concentrations. Only Canada geese from the CDA River Basin, in spite of lower blood lead concentrations, had significantly reduced mean hemoglobin and hematocrit values. No euthanized Canada geese (all HYs) from CDA River Basin were classified as clinically lead poisoned, but 38 Canada geese found dead in the CDA River Basin during a concurrent study succumbed to lead poisoning between 1992 and 1997. Only 6 (15.8%) of these 38 contained ingested lead shot, which contrasts greatly with the 75–94% incidence of ingested lead shot when mortality was due to lead shot ingestion. Lead from other contaminated sources ( i.e ., sediments and vegetation) in the CDA River Basin was strongly implicated in most Canada goose deaths. Based on the 31 live mallards and Canada geese collected in the CDA River Basin, which were representative of the live populations blood sampled only, the prevalence of subclinical and clinical lead poisoning (as determined by liver lead concentrations, excluding birds with ingested lead shot) was higher in mallards: subclinical (4 of 8, 50% HYs and 6 of 11, 55% adults); clinical (0% HYs and 4 of 11, 36% adults), with less data available for Canada geese (only 1 of 9, 11% HYs marginally subclinical). The clinically lead-poisoned mallards had extremely high concentrations of lead in blood (2.69–8.82 μg/g) and liver (6.39–17.89 μg/g). Eight mallards found dead in the CDA River Basin during a concurrent study were diagnosed as lead poisoned, and only one (12.5%) contained ingested lead shot, which again strongly implicates other lead sources. The finding of dead lead poisoned Canada geese together with the high percentage of live mallards classified as subclinically or clinically lead poisoned, in combination with the low incidence of ingested lead shot causes us concern for both of these species, which live in association with lead-contaminated sediment in the CDA River Basin.

Idaho

Effects of oral doses of fluoride on nestling European starlings

Nestling European starlings ( Sturnus vulgaris ), raised and fed by free-living adults, were given daily oral doses of either distilled water, 193 mg sodium as Na 2 CO 3 per kg of body weight (sodium control group), or 6, 10, 13, 17, 23, 30, 40, 80, 160 mg of the fluoride ion as NaF in distilled water per kg of body weight (mg/kg). Dosing began when nestlings were 24–48 hr old and continued for 16 days. The 24-hr LD 50 of fluoride for day-old starlings was 50 mg/kg. The 16-day LD 50 was 17 mg/kg. The sodium control group did not differ from the water control group with respect to any of the measured variables. Growth rates were significantly reduced in the 13 and 17 mg of fluoride/kg groups; weights of birds given higher dose levels were omitted from growth comparisons because of high, fluoride-induced mortality. Although prefledging weights for the 10, 13, and 17 mg of fluoride/kg groups averaged 3.6 to 8.6% less than controls at 17 days, this difference was not significant. Feather and bone growth of the fluoride and control groups were not different, except for keel length measured at 17 days of age which averaged less in the fluoride groups. Liver and spleen weights were not affected by fluoride treatments. No histological damage related to fluoride treatments was found in liver, spleen, or kidney. The logarithm of bone fluoride and magnesium concentration increased with the logarithm of increasing fluoride treatment levels and were significantly correlated with each other. Fluoride treatments had no effect on percent calcium or phosphorus in bone or plasma alkaline phosphatase activity. Oral doses of fluoride appear to be more toxic than equivalent dietary levels. Most birds probably acquire fluoride through their diet. Therefore, the results of the study may overstimate the potential effects of fluorides on songbirds living in fluoride-contaminated environments.

Archives of Environmental Contamination and Toxico

DENSITY: software for analysing capture-recapture data from passive detector arrays

A general computer-intensive method is described for fitting spatial detection functions to capture-recapture data from arrays of passive detectors such as live traps and mist nets. The method is used to estimate the population density of 10 species of breeding birds sampled by mist-netting in deciduous forest at Patuxent Research Refuge, Laurel, Maryland, U.S.A., from 1961 to 1972. Total density (9.9 ? 0.6 ha-1 mean ? SE) appeared to decline over time (slope -0.41 ? 0.15 ha-1y-1). The mean precision of annual estimates for all 10 species pooled was acceptable (CV(D) = 14%). Spatial analysis of closed-population capture-recapture data highlighted deficiencies in non-spatial methodologies. For example, effective trapping area cannot be assumed constant when detection probability is variable. Simulation may be used to evaluate alternative designs for mist net arrays where density estimation is a study goal.

Animal Biodiversity and Conservation

Low prevalence of avian influenza virus in shorebirds on the Pacific coast of North America

The emergence of highly pathogenic avian influenza (HPAI) H5N1 has elevated concerns about wild birds as virus hosts; however, little is known about the ecological and epidemiological factors of transmission by shorebirds. Here we summarize results for 2,773 shorebirds that were live-trapped on the Pacific coast of the United States during 2006-2007 and tested for avian influenza virus using real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and virus isolation. As was the case throughout North America, HPAI H5N1 was not detected in shorebirds during this interval. Contrary to other wild bird groups, most notably waterfowl, the prevalence of even low pathogenicity virus among shorebirds in our study areas in California, Washington, and Alaska was extremely low (0.5%). Virus was detected by RT-PCR from four different species, including, Dunlin (Calidris alpina; N = 3), Western Sandpiper (C. mauri; N = 8), Long-billed Dowitcher (Limnodromus scolopaceus; N = 1), and American Avocet (Recurvirostra americana; N = 1), with the detections in the latter three constituting the first published records for these birds. Based on studies in the eastern United States, we expected, but did not detect (H 1 = 1.6, P = 0.21) elevated avian influenza prevalence among shorebirds during spring migration. Diagnostic tests, which were designed to evaluate testing and sampling methods, indicated poor functioning of traditional virus isolation methods and no improvement in detection likelihood by collecting oropharyngeal swabs in addition to cloacal swab samples for low pathogenicity viruses (Z 1 = 0.7, P = 0.48).

Waterbirds

Effects of field applications of heptachlor on bobwhite quail and other wild animals

A study of the effects of field applications of heptachlor on bobwhite quail ( Colinus uirginianus ) and other animals was conducted on three similar areas, two in Decatur County, Georgia, and one in Escambia County, Alabama, from February, 1958, to March, 1962. Heptachlor in granules was applied by aircraft on the Georgia areas for eradication of the imported fire ant ( Solenopsis saevissima ). Applications were directed by personnel of the U. S. Department of Agriculture, Plant Pest Control Division. The Alabama area remained untreated. Transects where whistling cocks were counted were superimposed on areas where coveys were counted. Size of areas varied from 14,000 to 20,000 acres. Each area had six transects, totaling 11,000 acres. Whistling cock bobwhites and coveys averaged 28 and 20 per 1,000 acres, respectively, the year before treatment on a Georgia area, and cocks and coveys averaged 25 per 1,000 acres for the duration of the study on the untreated Alabama area. Where portions of an area were treated at 2 pounds of heptachlor per acre, whistling cocks and coveys were reduced significantly, with a greater reduction where a greater amount of land was treated on the area or its transects. A decline of cocks and coveys also followed 1/2-pound applications (approaching statistical significance for coveys). Three years after treatment, cock and covey numbers were below those recorded before treatment. Whistling cocks and coveys also declined on adjoining land which remained untreated (significant for cocks, approaching significance for coveys). This decline was attributed to movements of bobwhites from untreated land to repopulate treated land. There is evidence that some loss occurred in bobwhites after they moved from untreated to treated land; the decrease in each instance was ascribed to the application of heptachlor. Songbirds were listed on the two Georgia areas. The first summer, eight more species and 458 more individuals of permanent resident birds were listed on the untreated area than on the treated area. After half of the originally untreated area was treated with heptachlor at 2 pounds per acre the following winter, the number of resident birds declined 37 percent. Some species of summer resident birds could not be found on treated land after heptachlor was applied. A small plot of 4 acres was intensively searched for dead and dying animals, and observations were made on living animals. Forty-seven days after treatment, no live animals were seen or heard on the plot, and a total of 38 dead animals had been found. Soils were sampled twice after treatment, and residues had declined in the second lot of samples. Twice animals also were obtained for analysis, and residues declined in the second group. Numbers of birds increased in the same period.

Alabama, Georgia

Organochlorine residues in eggs of loggerhead and green sea turtles nesting at Merritt Island, Florida--July and August, 1976

Eggs from nine clutches of loggerhead turtles (Caretta caretta) and two clutches of green turtles (Chelonia mydas) were collected as they were laid on Merritt Island, Florida. Eggs were incubated, frozen, and analyzed for organochlorines. Levels of DDE and PCB, the major contaminants, averaged less than 0.08 ppm in loggerhead eggs and were even lower in green turtle eggs. These concentrations are far below levels thought to be potentially harmful. Loggerhead eggs were frozen after 43-52 days incubation; both DDE and PCB declined significantly during this interval. Authors estimate that DDE averaged about 0.2 ppm in loggerhead eggs when they were laid. DDE levels in eggs of both turtle species were less than levels in eggs of crocodiles (Crocodylus acutus) from Everglades National Park and in eggs of 13 species of aquatic birds nesting on Merritt Island. The remarkably low residues in the turtle eggs probably indicate that, when not nesting, the turtles live and feed in areas remote from Florida.

Pesticides Monitoring Journal

Palila Restoration: Lessons from Long-term Research

BACKGROUND The palila (Loxioides bailleui) is a member of the Hawaiian honeycreeper family of birds (Drepanidinae), which is renowned for the profusion of species - many with bizarre bills and specialized feeding habits - that radiated from a single ancestral type. Most of the 57 or so honeycreeper species are extinct, and the palila is endangered because of its high degree of dependence on the mamane tree (Sophora chrysophylla) (Figure 1) and its restricted distribution on the upper slopes of Mauna Kea (Figure 2). Three decades of research have revealed many important facts about palila, providing the foundation and impetus for conservation programs in the wild and captivity. Additionally, an ambitious public conservation campaign arose due to the land-use conflicts on Mauna Kea. Here we summarize progress in palila conservation biology and outline steps that might overcome the remaining major challenges to its recovery. We also highlight lessons learned from palila research that may help the recovery of other Hawaiian forest birds. Palila and two closely-related species on the tiny islands of Nihoa and Laysan are the last of the seed-eating honeycreeper species in the Hawaiian Islands. About a quarter of the honeycreeper species known from living and fossil specimens had finch-like bills suited mainly for eating seeds and fruits. Because of their dietary specialization, palila are vulnerable to changes in forest size and quality, as was also likely the case for extinct species of seed specialists. Palila and many other forest bird species were once distributed in dry, lowland forests. Fossil records indicate that palila also occurred in the lowlands of O`ahu and Kaua`i until human settlement of those islands. However, because lowland habitats have been highly modified by humans and because mamane occurs today primarily at high elevation, palila are the only native bird species found exclusively in dry, subalpine habitat (2000?2850 m). Similar to other feeding specialists, palila lay few eggs, raise few young each year, and take a relatively long time to complete the nesting cycle. Low rates of reproduction result in low rates of population growth and low potential for recovery from disturbances. Long-term studies of palila offer important insights into the conservation biology of all Hawaiian forest bird species, particularly feeding specialists like the palila. Palila face many challenges common to both generalist and specialist Hawaiian honeycreeper species. Habitat loss and degradation, as well as introduced avian diseases, have reduced their numbers and limited their distribution to a very small portion of their historic range. Introduced mammals prey on palila, while alien insects reduce caterpillars that are particularly important in the diet of nestlings. Securing legal protection and funding for palila restoration has been challenging. Understanding how the palila has avoided extinction can help managers plan its recovery, and better design recovery plans for species with different feeding strategies in other habitats.

Fact Sheet