Search

Supplementary food resources (e.g., subsidies) associated with agriculture can benefit wildlife species, increasing predictability and availability of food. Avian scavengers including raptors often utilize subsidies associated with both recreational hunting and pest shooting on agricultural lands. However, these subsidies can contain lead (Pb) fragments if they are culled with Pb-based ammunition, potentially leading to Pb poisoning and physiological impairment in wildlife. Nesting Golden Eagles (Aquila chrysaetos) commonly forage in agricultural lands during the breeding season, and therefore, both adults and their nestlings are susceptible to Pb exposure from scavenging shot wildlife. We assessed drivers of Pb exposure in 258 nestling Golden Eagles (401 total blood samples), along with physiological and growth responses, in agricultural lands across four western states in the United States. We also evaluated the birds’ Pb stable isotope signatures to inform exposure sources. Twenty-six percent of Golden Eagle nestlings contained Pb concentrations associated with subclinical poisoning for sensitive species (0.03–0.2 lg/g ww), 4% had Pb concentrations that exceeded subclinical poisoning benchmarks (0.2–0.5 lg/g ww), and <1% exceeded either concentrations associated with clinical poisoning (0.5–1.0 lg/g ww) and or those deemed to cause severe clinical poisoning (>1.0 lg/g ww). Lead concentrations were highest in nestlings with close proximity to fields that potentially provided subsidies and declined exponentially as distance to subsidies increased. However, close proximity to agriculture, and presumably subsidies, positively influenced nestling growth rates. Across the range of Pb exposure, nestlings experienced a 67% reduction in delta-aminolevulinic acid dehydratase (d-ALAD) activity, suggesting nestlings may have been anemic or experiencing cellular damage. Isotopic ratios of 206Pb/207Pb increased non-linearly with increasing blood Pb in Golden Eagle nestlings, and 45% of the birds were consistent with those of ammunition. However, above 0.10 lg/g ww, the proportion associated with ammunition increased to 89% of the nestlings. An improved understanding of how these positive (growth) and negative (physiology) effects associated with proximity to subsidies interact would be beneficial to managers when considering management scenarios and potentially evaluating any measures taken to reduce Pb exposure across the landscape. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Field Ornithology is the property of Resilience Alliance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Contaminant exposure of tree swallows, Tachycineta bicolor, nesting in 27 Areas of Concern (AOCs) in the Great Lakes basin was assessed from 2010 to 2014 to assist managers and regulators in their assessments of Great Lakes AOCs. Contaminant concentrations in nestlings from AOCs were compared with those in nestlings from nearby non-AOC sites. Polychlorinated biphenyl (PCB) and polybrominated diphenyl ether concentrations in tree swallow nestling carcasses at 30% and 33% of AOCs, respectively, were below the mean concentration for non-AOCs. Polycyclic aromatic hydrocarbon (PAH) concentrations in nestling stomach contents and perfluorinated compound concentrations in nestling plasma at 67% and 64% of AOCs, respectively, were below the mean concentration for non-AOCs. Concentrations of PCBs in nestling carcasses were elevated at some AOCs but modest compared with highly PCB-contaminated sites where reproductive effects have been documented. Concentrations of PAHs in diet were sufficiently elevated at some AOCs to elicit a measurable physiological response. Among AOCs, concentrations of the perfluorinated compound perfluorooctane sulfonate in plasma were the highest on the River Raisin (MI, USA; geometric mean 330 ng/mL) but well below an estimated toxicity reference value (1700 ng/mL). Both PAH and PCB concentrations in nestling stomach contents and PCBs in carcasses were significantly correlated with concentrations in sediment previously reported, thereby reinforcing the utility of tree swallows to assess bioavailability of sediment contamination. Environ Toxicol Chem 2017;36:735-748. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America. [ABSTRACT FROM AUTHOR]

Relationships between foraging habitat and reproductive success provide compelling evidence of the contribution of specific vegetative features to foraging habitat quality, a potentially limiting factor for many animal populations. For example, foraging habitat quality likely will gain importance in the recovery of the threatened red-cockaded woodpecker Picoides borealis (RCW) in the USA as immediate nesting constraints are mitigated. Several researchers have characterized resource selection by foraging RCWs, but emerging research linking reproductive success (e.g. clutch size, nestling and fledgling production, and group size) and foraging habitat features has yet to be synthesized. Therefore, we reviewed peer-refereed scientific literature and technical resources (e.g. books, symposia proceedings, and technical reports) that examined RCW foraging ecology, foraging habitat, or demography to evaluate evidence for effects of the key foraging habitat features described in the species' recovery plan on group reproductive success. Fitness-based habitat models suggest foraging habitat with low to intermediate pine Pinus spp. densities, presence of large and old pines, minimal midstory development, and herbaceous groundcover support more productive RCW groups. However, the relationships between some foraging habitat features and RCW reproductive success are not well supported by empirical data. In addition, few regression models account for > 30% of variation in reproductive success, and unstandardized multiple and simple linear regression coefficient estimates typically range from -0.100 to 0.100, suggesting ancillary variables and perhaps indirect mechanisms influence reproductive success. These findings suggest additional research is needed to address uncertainty in relationships between foraging habitat features and RCW reproductive success and in the mechanisms underlying those relationships. [ABSTRACT FROM AUTHOR]

Mercury (Hg) is a ubiquitous environmental contaminant that is transferred trophically through aquatic and terrestrial food webs. To better understand the routes of Hg uptake in organisms that rely on both aquatic and terrestrial food resources, we analyzed feather and down samples from nestling wading birds of varying trophic positions in both inland and coastal colonies. We used stable nitrogen and carbon isotope analyses to evaluate trophic positions of individual species (δN) and differences in foraging habitat use (δC). Inland, aquatic species had higher trophic status than the single terrestrial species examined, and the expected positive relationship between δN and Hg content of feathers was observed. However, the same was not true for all species from coastal colonies. Feathers from species that primarily consumed saltwater prey were relatively high in δN value and low in Hg content, which is opposite of the trend expected due to Hg biomagnification in food chains. In contrast, coastal species foraging in freshwater or a combination of freshwater and saltwater habitats displayed greater Hg contents in feathers. The apparent differential use of the two aquatic systems (freshwater and saltwater) in coastal environments by wading bird species results in variations in δN values and Hg contents in nestling feathers not found in species associated with only freshwater systems. [ABSTRACT FROM AUTHOR]

Concentrations of polychlorinated dibenzofurans (PCDFs) and other dioxin-like compounds in soils and sediments of the Tittabawassee River and associated floodplains downstream of Midland, Michigan, USA, are greater than upstream sites. As a result of these concentrations, which are some of the greatest ever reported, a site-specific exposure assessment of belted kingfisher breeding in the assessment area was conducted. To reduce the uncertainty associated with predicting exposure from abiotic matrices, concentrations of residues were quantified in site-specific prey items and in eggs and nestlings of belted kingfisher. Dietary exposure, expressed as the potential average daily dose, based on site-specific concentrations of PCDFs, polychlorinated dibenzo- p-dioxins (PCDDs), and 2,3,7,8-tetrachlorodibenzo- p-dioxin equivalents (TEQWHO-Avian) in prey items was consistently greater along the Tittabawassee River than in associated reference areas and further downstream sites in the Saginaw River. Concentrations of PCDD/DFs in eggs and nestlings of belted kingfisher varied among sampling areas, being greater in both eggs and nestlings nesting along the Tittabawassee River compared to those of belted kingfisher from upstream reference areas. Geometric mean concentrations of PCDD/DFs were 130 and 200 ng/kg wet weight in eggs and nestlings of belted kingfisher, respectively. These concentrations are the equivalent of 84 and 95 ng TEQWHO-Avian/kg. Site-specific biomagnification factors for select PCDD/DF congeners ranged from <1.0 to 1.8 in belted kingfisher. Environ. Toxicol. Chem. 2012; 31: 1158-1168. © 2012 SETAC [ABSTRACT FROM AUTHOR]

Red-headed woodpecker ( Melanerpes erythrocephalus) populations have declined in the United States and Canada over the past 40 years. However, few demographic studies have been published on the species and none have addressed adult survival. During 2006-2007, we estimated survival probabilities of 80 radio-tagged red-headed woodpeckers during the breeding season in mature loblolly pine ( Pinus taeda) forests in South Carolina. We used known-fate models in Program MARK to estimate survival within and between years and to evaluate the effects of foliar cover (number of available cover patches), snag density treatment (high density vs. low density), and sex and age of woodpeckers. Weekly survival probabilities followed a quadratic time trend, being lowest during mid-summer, which coincided with the late nestling and fledgling period. Avian predation, particularly by Cooper's ( Accipiter cooperii) and sharp-shinned hawks ( A. striatus), accounted for 85% of all mortalities. Our best-supported model estimated an 18-week breeding season survival probability of 0.72 (95% CI = 0.54-0.85) and indicated that the number of cover patches interacted with sex of woodpeckers to affect survival; females with few available cover patches had a lower probability of survival than either males or females with more cover patches. At the median number of cover patches available ( n = 6), breeding season survival of females was 0.82 (95% CI = 0.54-0.94) and of males was 0.60 (95% CI = 0.42-0.76). The number of cover patches available to woodpeckers appeared in all 3 of our top models predicting weekly survival, providing further evidence that woodpecker survival was positively associated with availability of cover. Woodpecker survival was not associated with snag density. Our results suggest that protection of ≥0.7 cover patches per ha during vegetation control activities in mature pine forests will benefit survival of this Partners In Flight Watch List species. © 2011 The Wildlife Society. [ABSTRACT FROM AUTHOR]

The article discusses a study on the development of a general Bayesian modeling framework appropriate for estimating survival of both bird nests and their young. During the two-year study period, survival data of Common Goldeneyes ducklings located in central Alaska and in the Missouri Coteau region of North Dakota have been collected and analyzed. Goodness-of-fit of the fixed-effects models has been measured using a version of the Bayesian predictive value that evaluated the fit of empirical survival curve and the fit of predicted survival curve.

Numerous factors, including nest predation and brood parasitism, may limit populations of neotropical migratory birds. However, nest predation and brood parasitism are not constant, and temporal, biological, habitat, and landscape factors can affect the likelihood of these events. Understanding these patterns is important for species of conservation concern for which managers seek to provide quality habitat. One such species, the Swainson's warbler (Limnothlypis swainsonii), is a neotropical migrant that breeds primarily in bottomland hardwood forests of the southeastern United States. Little is known of factors influencing reproductive success of this rare, yet locally abundant, species. From 2004 through 2007, we examined factors influencing reproductive success of Swainson's warblers at 2 sites in eastern Arkansas, USA, St. Francis National Forest and White River National Wildlife Refuge. We used 2-stage modeling to assess the relationship between 1) temporal and biological, and 2) habitat and landscape factors and brood parasitism, nest survival, and fledgling production. Brood parasitism was greater in this population (36%) than reported elsewhere ( ≤10%), but decreased throughout the breeding season. Nest survival was comparable to or lower than in other populations of this species and increased throughout the breeding season. The probability of brood parasitism was greater near forest edges. Although nests of Swainson's warblers were often associated with giant cane (Arundinaria gigantea), nest survival had a weak negative association with cane density. For nests that were successful, the best predictor of number of Swainson's warblers fledged was brood-parasitism status: nonparasitized nests fledged 2.75 young, whereas parasitized nests fledged 0.60 Swainson's warblers. Our findings suggest that managing and restoring relatively high-elevation bottomland forests that are located far from agricultural edges should increase Swainson's warbler productivity. [ABSTRACT FROM AUTHOR]

The article discusses a study on the biotic and abiotic factors that govern the nestling-period length in Seiurus aurocapilla, also known as Ovenbird, found in the U.S. The day of fledging was determined by visiting the nests in the morning after the nesting cycle. Also included are the influence of food availability on the nestling-period length, the greatest variation in nestling period, and the role of parental behavior and quality within the framework in the length of the nestling period.

Ectoparasitism of nesting birds is known to impact reproduction for many species including cavity-nesting swallows and ground-nesting colonial seabirds. Little information is available from wading birds (e.g., herons, egrets, ibises). We documented skin-eating dermestid beetle abundance in 261 wading-bird nests in seven heronries located in northeastern US estuaries during 1991 2000. Beetles were collected after fledglings were no longer using the nest. We examined all twigs and debris for larval and adult beetles, and excavated holes in twigs to count pupating insects. In addition, nest size was evaluated. Dermestes nidum (dermestid beetle) larvae were prominent members of nest faunal communities in all estuaries. We detected no evidence that beetle abundance correlated with wading-bird species, nest reuse, nest substrate species, or nest-collection date. Regression analysis and partial correlation analysis identified nest size, colony, and year as factors showing a significant relationship with beetle abundance after accounting for all known factors. [ABSTRACT FROM AUTHOR]

The article presents a study, which has used band recovery data for evaluating distances between locations of recovery for 154 nestling Florida Bald Eagles while discussing the understanding natal dispersal implications and the philopatry among the species. It has been observed that female and younger birds in particular, had longer distances for recovery among the 21 mature eagles of known banding and sex. The study suggests that the records being examined show higher level of philopatry as well as short distances for natal dispersal specifically in male Bald Eagles.

We collected diet data at 12 Ferruginous Hawk (Buteo regalis) and 14 Swainson's Hawk (B. swainsoni) nests in a short-grass prairie and agricultural community in the panhandle area of northwest Texas and southwest Oklahoma, and in northeastern New Mexico during the 2003-2004 breeding seasons. We documented 959 Ferruginous Hawk and 1.058 Swainson's Hawk prey deliveries during --5,618 hrs of video monitoring. Ferruginous Hawks delivered 10.0 ± 0.7 (x̄ ± SE) prey species per nest and typically larger prey. Swainson's Hawks delivered 13.4 ± 1.1 prey species per nest and typically smaller prey. There was a dietary overlap (Simplified Morisita Index [CH]) of 0.31 in prey species delivery frequency and 0.56 in prey species' biomass. Ferruginous Hawks made 4.6 deliveries/day at 480 g/delivery whereas Swainson's Hawks delivered smaller prey items (147 g/delivery) but more frequently (7.0 deliveries/day). Deliveries/day and mass/day increased with increasing brood sizes of both species, but deliveries/day/nestling and mass/day/nestling decreased. Provisioning rates did not vary significantly over the nestling period. These data represent the most accurate diet quantification to date for Ferruginous and Swainson's hawks. Ferruginous Hawks used a larger array of prey types than shown in other studies based on indirect diet analysis methods. The low interspecific diet overlap suggests that prey is partitioned, which may facilitate the well-documented sympatric distribution of the two species. [ABSTRACT FROM AUTHOR]

Many studies investigating edge effects on forest-nesting birds have focused on nest success. Fewer have examined edge effects on other components of fitness. Nestling growth rates have been positively correlated with food availability, which may differ at edges compared to the forest interior. However, previous work has not examined growth as a function of distance to edge and edge type. We investigated whether edge type, distance to edge, hatching date, brood size, brood parasitism, year, and site influenced growth rates of wings, tarsi, and mass of nestling Wood Thrushes (Hylocichla mustelina) using regression tree analyses. Simultaneously, we examined edge effects on daily nest survival. We conducted our study in southwestern Michigan in 2002 and 2003. We located 175 nests and measured nestlings from 61 nests. Contrary to expectations, tarsal and mass growth rates were more rapid near edges than in the forest interior and tarsal growth rates were more rapid near gradual edge types than near abrupt edge types. Wing chord growth rates were more rapid in the forest interior than at edges. Mass and tarsal growth rates were more rapid later in the breeding season, when brood sizes were smaller. We found no effect of edge type or distance to edge on nest survival. The influence of edge on nestling growth rate but not nest survival suggests nestling growth rates may indicate edge-interior and edge type differences in habitat quality, even when high regional fragmentation levels overwhelm potential edge-interior differences in nest survival. [ABSTRACT FROM AUTHOR]

The article presents a study on the reproductive success of savannah sparrow and bobolinks, grassland songbirds, in a dynamic management landscape in the U.S. The study, which was conducted with four grassland treatments, has differed among treatments and between species regarding both the number of fledglings per female per year and nest success. The study has suggested a 65-day interval between cuts might provide enough time for both species to successfully fledge young for fields first cut in May.

We analyzed the body condition of nestling Burrowing Owls (Athene cunicularia) at Buffalo Gap National Grassland during the summers of 1999 and 2000. In 1999, which had a wet spring, body condition was negatively related to brood size and distance from nest to colony edge. There was no relationship between body condition and brood size during 2000, which had normal precipitation. In 2000, nestlings of early arriving pairs were in better body condition than those that arrived later The variance in body condition within a brood was not related to brood size. [ABSTRACT FROM AUTHOR]

We studied bird density and nesting success on utility rights-of-way (ROW) managed primarily by selective herbicide application in New York, Massachusetts and Maine. For comparison, we also estimated bird density in ROW managed by cutting in New Hampshire and New York and in shrublands managed by fire in the Finger Lakes National Forest (FLNF), New York. On herbicide-managed ROW, we detected a mean of 14.3 individuals and 12.2 species per point count, including many species of early-succession habitat that are declining throughout northeastern United States. Nesting success in forested landscapes of New York, Maine, and Massachusetts was 55% on the ROW, 69% in forests within 20 m of the ROW, and 63% in forests more than 20 m from the ROW. Brown-headed cowbirds (Molothrus ater) parasitized 5.3% of the nests and reduced host recruitment by even less. This suggests that ROW in forested areas support high production of shrubland birds and do not exert a measurably harmful effect on forest-nesting birds. Selective herbicide application on ROW sustained shrubland vegetation and supported high densities and high nesting success. Mechanical cutting lowered the structural diversity of vegetation the following spring and was associated with fewer individual birds and species. Cool burns in early spring produced a high structural diversity of herbs, shrubs and trees and supported a high density of birds and bird species. Long-term maintenance of shrublands by burning will require supplemental cutting to remove saplings. As reforestation continues to reduce shrubland habitat, probably below pre-colonial levels, active management for early-succession habitat will be necessary to sustain current population levels of numerous species. [Copyright &y& Elsevier]

Summary 1. Development plasticity is a common evolutionary and phenotypic response to poor growth condition, in particular in organisms with determinate growth such as most birds and mammals. Because various body structures can contribute differently to overall fitness, natural selection will adjust the degree of plasticity of each structure to its proportionate contribution to fitness at a given life stage. 2. Two non-mutually exclusive mechanisms can account for plasticity in the growth of offspring to compensate for the effect of parasites. First, if parasite infestation levels fluctuate over the nestling period, parasitized young may show reduced growth until peak parasite infestation, and accelerated growth once the conditions improve (the accelerated growth hypothesis). Secondly, if the period of tissue maturation is not fixed in time, hosts may grow slower than parasite-free hosts but for a longer period of time (the delayed maturation hypothesis). 3. To test whether hosts compensate for the effects of parasites on their development, the load of the blood-sucking louse-fly Crataerina melbae Rondani in the nests of Alpine swifts, Apus melba Linnaeus, was increased or decreased experimentally. Parasite prevalence was 100% in both treatments, but intensity (no. of parasites per nestling) was significantly lower for deparasitized nestlings. In both treatments, parasite intensity increased up to halfway through the rearing period (i.e. 30 days of age) and decreased afterwards. 4. In line with the accelerated growth hypothesis, wings of parasitized nestlings grew at a lower rate than those of deparasitized ones before the peak of parasite infestation, but at a greater rate after the peak. Louse-flies had no significant effect on the growth of body mass. In agreement with the delayed-maturation hypothesis, wings of parasitized nestlings grew for 3 additional days and were of similar size at fledging as in deparasitized birds. 5. In summary, the present study shows in a wild bird population that nestling hosts can compensate for the effect of parasitism on their phenotype. It emphasizes the need to take the dynamics of parasite populations into account in studies of host–parasite relationships, and to investigate the effect of parasites on host development over the entire growing period rather than only at fledging, as employed traditionally. [ABSTRACT FROM AUTHOR]

Presents a study that recorded temperatures of the nest cup and air just outside the nest box throughout the development of tree swallow or Tachycineta bicolor chicks in east-central Minnesota. Manipulation of the brood size; Effect of the number of chicks on the nest's thermal environment; Independence of the temperature of the nest cup from the air outside the nest box.

Presents a study which monitored the nesting biology of color-banded populations of the Louisiana Waterthrush or seiurus motacilla across Pennsylvania from 1996-2001. Review of related literature on bird polgyny; Study area and methods; Results of the study.

Studies Ovenbirds in forest fragments in a suburban landscape in eastern Massachusetts to determine effects of cowbird parasitism on Ovenbird reproductive success. Percentage of nests found to be parasitized by cowbirds; Comparison of fates of parasitized and unparasitized nests; Average number of fledglings from successful nests in small and large forests.

Presents a study that identified changes in nesting populations for several species of colonial waterbirds in Jamaica Bay Wildlife Refuge (JBWR) in New York and on Long Island, New York from 1974 to 1998 to provide a basis for wildlife management decisions in JBWR and also at nearby John F. Kennedy International Airport in New York City. Absence of stability in the population; List of birds that increased their population in JBWR; Disappearance of cattle egrets from the refuge.

Presents information on a study which documented effects of brown-headed cowbird parasitism on chipping sparrows in southwest Colorado. Methods; Chipping sparrow growth in nests with and without a brown-headed cowbird nestling; Number of chipping sparrow clutches initiated and number of nests that were parasitized by brown-headed cowbirds during one-week periods.

Focuses on a study which measured field metabolic rate (FMR) of nestling bald eagles in northern Wisconsin. Use of doubly-labeled water in measuring nestling energy expenditure to determine energy requirements of nestlings; Combined data from Lake Superior and inland nestlings for stepwise multiple regression; FMR as a function of nestling age for inland and Lake Superior nestlings.

Discusses the response of the authors on the argument that they failed to demonstrate in their study a difference in productivity between pairs of Cooper's hawks in urban and exurban areas in Arizona. Response on the criticism that the authors did not provide information on nest density on the Exurban Study Area (ESA); Why the comparative reproductive data from the ESA would not be necessary to define the Tucson Study Area as a sink.

Presents information on bigamous male Northern Cardinals in Dayton, Ohio. Description of the bird; Nestling periods of the females; Paternal care.

Discusses the chronology of microbial colonization of nestling Tree Swallows (Tachycineta bicolor) in Michigan. Effects of microbes on fledgling condition; Time course characterization of microbial colonization of the cloacae of nestling Tree Swallows; Relationship between cloacal microbes and fledgling condition; Similarity of nest mates assemblages of cloacal microbes.

Examines survival and reproduction of female eastern wild turkeys in south-central New York during 1990-1993. Sensitivity analysis to determine the relative importance of demographic paramaters; Seasonal survival rates for different seasons; Annual variation in nest success, hen success and hatching rates.

Measures feeding rates of nestlings by the dichromatic Northern Cardinal in Dayton, Ohio. Rates of male feeding patterns; Measurement as rate per brood and nestling; Correlation of male feeding efforts; Methods for providing of food; Demonstration of male significant parental effort.

Presents a study where a number of fledging Wood Thrushes were monitored to investigate movement and habitat use during the postfledging period. Definition of fledging; How the structure and composition of vegetation was characterised; Methodology used to conduct study; Results of study.

I observed a male Brown-headed Cowbird (Molothrus ater) attack and kill a nestling of an unidentified passerine in a grassland field in Day County, South Dakota, in June 2000. The killing or removal of nestlings by female cowbirds has been reported by others, but this behavior has not been documented previously in male cowbirds. [ABSTRACT FROM AUTHOR]

Presents a study which examined the incidence of trichomoniasis in nestling and fledging Cooper's Hawks in Arizona. Study area and methods; Results of the study.

Black-throated Blue Warblers (Dendroica caerulescens) are subject to nest predation by a variety of avian and mammalian species. I present evidence that slugs (Gastropoda; Mollusca) can also function as nest predators. On two occasions, slugs were observed feeding on 6-7 day-old nestling Black-throated Blue Warblers at Hubbard Brook Experimental Forest. New Hampshire, USA. This is apparently the first report documenting that slugs can function as avian nest predators. [ABSTRACT FROM AUTHOR]

The article presents information on research papers related to grasslands. The paper "Grazing and Wildlife," by S. Clubine, published in the "Native Warm-Season Grass Newsletter," discusses the problems grazing cattle cause for grassland nesting birds. The greatest concern is nest trampling, especially in densely stocked paddocks grazed in rapid rotations. The paper "Application of the Fire-grazing Interaction to Restore a Shifting Mosaic on Tallgrass Prairie," by S.D. Fuhlendorf and D.M. Engle, published in the "Journal of Applied Ecology," compares ecologically based rangeland management with traditional management to see if either could produce a shifting mosaic of vegetation characteristic of pre-Columbian tallgrass prairie. The paper "American Prairie Overlooked No More," by S. Kinzer, published in the June 2004 issue of the journal "New York Times," highlights the Midewin National Tallgrass Prairie, the first federally designated prairie preserve in the United States. The paper "Dominance Not Richness Determines Invisibility of Tallgrass Prairie," by M.D. Smith, J.C. Wilcox, Theresa Kelly and Alan K. Knapp, published in the journal "Oikos," examines the effects of species richness and dominance on invasion by yellow sweet clover, an exotic legume, in a tallgrass prairie in Kansas.

Comments on the study regarding the breeding ecology of Cooper's hawks in urban and exurban areas of Tucson, Arizona. Analysis on the comparative nestling-fledgling mortality in the urban Tucson Study area (TSA); Calculation of the nest success rates at the time the broods were counted and banded; Mortality induced by trichomoniasis among urban fledglings in Tucson; Information which the authors of the study failed to provide.

The article focuses on the analysis of the behavior of the bird, goldfinches in the U.S. It has been recognized that goldfinches remain in the nation for the whole year round. It can also be noticed that it can be readily seen in summer, but in winter, they are not so brightly arrayed. They are usually the last bird to build its nest, postponing homebuilding until the fourth of July due to climate conditions.

The article focuses on the analysis of bird migration in the U.S. It is claimed that birds migrated in the country during summer from the South because it is safer for them to build their nests in the woods and fields than it is in the South. Birds then go South at the approach of winter to obtain food, and return to the North with the retreat of winter.