Geology Reports⌕ Search

Geology topics

D.G. McAuley

Publications and source records attributed to D.G. McAuley.

At least 19 recordsLinked to original sources
USGS2007

A multivariate assessment of changes in wetland habitat for waterbirds at Moosehorn National Wildlife Refuge, Maine, USA

We assessed changes in vegetative structure of 49 impoundments at Moosehorn National Wildlife Refuge (MNWR), Maine, USA, between the periods 1984-1985 to 2002 with a multivariate, adaptive approach that may be useful in a variety of wetland and other habitat management situations. We used Mahalanobis Distance (MD) analysis to classify the refuge?s wetlands as poor or good waterbird habitat based on five variables: percent emergent vegetation, percent shrub, percent open water, relative richness of vegetative types, and an interspersion juxtaposition index that measures adjacency of vegetation patches. Mahalanobis Distance is a multivariate statistic that examines whether a particular data point is an outlier or a member of a data cluster while accounting for correlations among inputs. For each wetland, we used MD analysis to quantify a distance from a reference condition defined a priori by habitat conditions measured in MNWR wetlands used by waterbirds. Twenty-five wetlands declined in quality between the two periods, whereas 23 wetlands improved. We identified specific wetland characteristics that may be modified to improve habitat conditions for waterbirds. The MD analysis seems ideal for instituting an adaptive wetland management approach because metrics can be easily added or removed, ranges of target habitat conditions can be defined by field-collected data, and the analysis can identify priorities for single or multiple management objectives.

Wetlands↗
USGS2006

Macroinvertebrate abundance, water chemistry, and wetland characteristics affect use of wetlands by avian species in Maine

Our objective was to determine use by avian species (e.g., piscivores, marsh birds, waterfowl, selected passerines) of 29 wetlands in areas with low (<200 μeq l −1 ) acid-neutralizing capacity (ANC) in southeastern Maine. We documented bird, pair, and brood use during 1982–1984 and in 1982 we sampled 10 wetlands with a sweep net to collect invertebrates. We related mean numbers of invertebrates per wetland to water chemistry, basin characteristics, and avian use of different wetland types. Shallow, beaver ( Castor canadensis )-created wetlands with the highest phosphorus levels and abundant and varied macrophyte assemblages supported greater densities of macroinvertebrates and numbers of duck broods (88.3% of all broods) in contrast to deep, glacial type wetlands with sparse vegetation and lower invertebrate densities that supported fewer broods (11.7%). Low pH may have affected some acid-intolerant invertebrate taxa (i.e., Ephemeroptera), but high mean numbers of Insecta per wetland were recorded from wetlands with a pH of 5.51. Other Classes and Orders of invertebrates were more abundant on wetlands with pH > 5.51. All years combined use of wetlands by broods was greater on wetlands with pH ≤ 5.51 (77.4%) in contract to wetlands with pH > 5.51 that supported 21.8% of the broods. High mean brood density was associated with mean number of Insecta per wetland. For lentic wetlands created by beaver, those habitats contained vegetative structure and nutrients necessary to provide cover to support invertebrate populations that are prey of omnivore and insectivore species. The fishless status of a few wetlands may have affected use by some waterfowl species and obligate piscivores.

Hydrobiologia↗
USGS2006

Macroinvertebrate abundance, water chemistry, and wetland characteristics affect use of wetlands by avian species in Maine

Our objective was to determine use by avian species (e.g., piscivores, marsh birds, waterfowl, selected passerines) of 29 wetlands in areas with low (<200 ueq 1-1) acid-neutralizing capacity (ANC) in southeastern Maine. We documented bird, pair, and brood use during 1982?1984 and in 1982 we sampled 10 wetlands with a sweep net to collect invertebrates. We related mean numbers of invertebrates per wetland to water chemistry, basin characteristics, and avian use of different wetland types. Shallow, beaver (Castor canadensis)-created wetlands with the highest phosphorus levels and abundant and varied macrophyte assemblages supported greater densities of macroinvertebrates and numbers of duck broods (88.3% of all broods) in contrast to deep, glacial type wetlands with sparse vegetation and lower invertebrate densities that supported fewer broods (11.7%). Low pH may have affected some acid-intolerant invertebrate taxa (i.e., Ephemeroptera), but high mean numbers of Insecta per wetland were recorded from wetlands with a pH of 5.51. Other Classes and Orders of invertebrates were more abundant on wetlands with pH > 5.51. All years combined use of wetlands by broods was greater on wetlands with pH < 5.51 (77.4%) in contrast to wetlands with pH > 5.51 that supported 21.8% of the broods. High mean brood density was associated with mean number of Insecta per wetland. For lentic wetlands created by beaver, those habitats contained vegetative structure and nutrients necessary to provide cover to support invertebrate populations that are prey of omnivore and insectivore species. The fishless status of a few wetlands may have affected use by some waterfowl species and obligate piscivores.

Conference Paper↗
USGS2005

Phylogeography of the American woodcock ( Scolopax minor ): Are management units based on band recovery data reflected in genetically based management units?

Information on population connectivity throughout the annual cycle has become more crucial, because populations of many migratory birds are in decline. One such species is the American Woodcock ( Scolopax minor ), which inhabits early-successional forests in eastern North America. Although band recoveries have proved useful for dividing populations of this game bird species into an Eastern Region and Central Region for management purposes, these data do not provide enough detail to determine the breeding population of origin of birds recovered on stopover and wintering areas. To obtain more fine-scale data, we undertook a phylogeographic study of American Woodcock populations throughout their primary breeding range in the eastern United States and Canada using mitochondrial DNA (mtDNA) sequences from the hypervariable control region I (CRI) and ND6 gene. Despite high haplotype diversity, nucleotide diversity was low and there was no phylogeographic structure among American Woodcock populations across the species range, with birds from many states and provinces in both management regions sharing identical haplotypes. Results suggest recent or ongoing gene flow among populations, with asymmetric movement of birds between migration flyways. As has been demonstrated for several other avian species in North America, American Woodcock appear to have undergone a rapid population expansion following the late Pleistocene glacial retreat. Thus, a combination of historical demographic factors and recent or ongoing gene flow mask any population structure based on mtDNA that might accrue from philopatry to breeding areas observed in studies of marked birds.

The Auk↗
USGS2004

Extraordinary size and survival of American black duck, Anas rubripes, broods

Two female American black duck, Anas rubripes, were initially observed during June 1982 with 20 Class Ib or 18-22 Class Ia-b ducklings in two wetlands in Hancock County, Cherryfield, Maine. Fifteen of 20 ducklings (75%) in one brood and 16 of 18-22 ducklings (72-89%) in the other brood survived to fledge. These large broods probably resulted from post-hatch brood amalgamation.

Maine↗
USGS2004

Dynamic use of wetlands by black ducks and mallards: Evidence against competitive exclusion

The decline of the American black duck ( Anas rubripes ) has been attributed to competition from mallards ( A. platyrhynchos ) that led to exclusive use of fertile wetlands by mallards. Data from annual breeding waterfowl surveys provide instantaneous, single observations of breeding pairs, which are used to estimate breeding population size and evaluate the condition of habitat. Data from these surveys have been used to document habitat use by black ducks and mallards. We used quiet-observation surveys from elevated platforms to study sympatric black ducks and mallards in northern Maine during the breeding season. Our objectives were to document occupancy of wetlands by breeding black ducks and mallards throughout the day during prenesting and early nesting periods to determine whether 1) wetlands were occupied by only a single species, 2) pairs of the same species occupied wetlands throughout the period, and 3) single observations of short duration adequately determine numbers and species using a wetland. We observed ducks at 5-minute intervals from elevated platforms on wetland margins to determine numbers and species of indicated pairs using each wetland over time. We visited 80% of the wetlands ≥2 times, with mean total time per wetland averaging 267 minutes. For each wetland we determined the most frequently observed grouping of black ducks and mallards from all combinations recorded during all intervals (e.g., 1 black duck [BO] pair during 9 intervals; 2 mallard [MA] pairs and 1 BO pair during 22 intervals; 0 pairs during 3 intervals). A single pair, a lone male, or no ducks were recorded during 34% of the 5-minute intervals. For wetlands with >2 hours of observations ( n =65 ), all but 2 were used by ≥2 different combinations of ducks. On most wetlands, the most frequent grouping was observed during <40% of the intervals. To simulate aerial surveys, we randomly selected 1 5-minute interval for each wetland. On average, the number of indicated pairs recorded during random 5-minute intervals was less than half of the total black duck pairs (2.0 vs. 4.4, P = 0.009 ), total mallard pairs (1.1 vs. 2.6, P= 0.0001), and pairs of both species combined (3.2 vs. 7.0, P= 0.0001) determined for each wetland based on total observations. On wetlands used by both species, random counts detected one or both species 49% of the time. Although 53 of the 65 wetlands observed ≥2 hours were used by both species, random visits detected both species on only 27 wetlands. Our data do not support assertions that the mallard has caused the decline of black ducks through interspecific competition for habitat, or that wetlands are occupied continuously by single pairs that aggressively exclude conspecifics. Our data indicated that single, short-duration visits with disturbance to wetlands are unreliable and inappropriate to document seasonal use of wetlands by breeding black ducks and mallards.

Maine↗
USGS2000

Survival of American black ducks radiomarked in Quebec, Nova Scotia, and Vermont

We monitored survival of 397 radiomarked juvenile American black ducks (Anas rubripes) distributed among Les Escoumins ( n = 75) and Kamouraska, Quebec ( n = 84), Amherst Point, Nova Scotia ( n = 89), and a site on the Vermont-Quebec border ( n = 149) during autumn 1990 and 1991. Eighty-six percent (215 of 250) of all confirmed mortalities during the study was from hunting; 72% of marked ducks were shot and retrieved and 14% were shot and unretrieved. We tested for differences in survival in relation to sex, body mass, year (1990-91, 1991-92), and among the 4 locations for each of 2 monitoring periods (early, EMP; late, LMP). With data from the EMP for Vermont-Quebec in 1990 and 1991, Les Escoumins in 1990, and Amherst Point in 1991, survival of hatching-year (HY) males and females did not differ ( P = 0.357). For sexes combined for the EMP, survival of ducks was greater in 1991 than 1990 ( P = 0.086), and differed among locations ( P = 0.013). Survival (years combined) was greater at Amherst Point than at Kamouraska ( P = 0.003) and Vermont-Quebec ( P = 0.002) during the EMP. The highest survival rate at Amherst Point (0.545 ± 0.056 [SE]) was associated with the latest date (8 Oct) of season opening; the lowest survival rate (0.395 ± 0.043) was at the Vermont-Quebec border, where hunter numbers and activity were greatest. For the LMP, no interaction between years and locations was detected ( P = 0.942), and no differences in survival existed between years ( P = 0.102) and among locations ( P = 0.349). No association was detected between body mass at capture and survival of combined males and females during the EMP ( P = 0.572) or during the LMP ( P = 0.965). When we censored hunting losses for combined years for each period, EMP or LMP, all survival estimates exceeded 0.800 (0.809-0.965). These data emphasize need for an improved harvest strategy for American black ducks in North America to allow for increases in breeding populations to achieve population goals.

Nova Scotia, Quebec, Vermont↗
USGS2000

Survival of female American Woodcock breeding in Maine

During 1986-1989, 89 female American woodcock (Scolopax minor) included in this study were radio-marked and survival estimated for the period 1 Aprii-15 June. Eleven woodcock died: five (45%) were killed by mammals, two (18%) by unknown predators, and one (9%) by a raptor; two (18%) died from entanglement in the transmitter harness; and 1 (9%) collided with a vehicle. Survival varied among years from 0.700 (1986) to 0.900 (1989) with a 4-year mean (95% CI) of 0.826. Survival did not differ between age classes (P = 0.900), or among years (P > 0.14), except for higher (P = 0.025) survival (0.875) in 1987 than in 1988 (0.735). A composite survival estimate--based on telemetry studies for the breeding, post-breeding, and winter periods-- was 0.363 for immatures and 0.474 for adults. Mean weights were not different between second year and after second year age classes (P = 0.167), but weight was related to woodcock capture date (P = 0.001). Survival for female woodcock was not related to mean snow depth or to mean, minimum temperature in winter or spring. Habitat use was different between females that died and those that lived, but sample size was small.

Book chapter↗
USGS2000

Assessing habitat selection in Spring by male American Woodcock in Maine with a geographic information system

Geographic information system (GIS) technology was used to identify habitats available to and used by male American woodcock (Scolopax minor) equipped with radio transmitters--54 in 1987, 51 in 1988, 46 in 1989 at Moosehorn National Wildlife Refuge, Maine. Woodcock were monitored from time of capture (25 March-15 April) to 15 June each year. To determine habitat selection by male woodcock, the following habitat characteristics were measured: land cover, age and stocking density of the forest overstory, soil drainage and texture, aspect, and percent slope. Habitat selection was examined as affected by the covariates weather and age-class of woodcock, and among years for diurnal and crepuscular periods of the breeding period. Multivariate techniques that compare use and availability of habitats were not available, so a statistical model was developed to rate importance of multiple habitat characteristics selected by woodcock. The most critical period for woodcock in terms of survival was from arrival to: mid-April. Second-year and after-second-year woodcock did not select different (P > 0.05) habitat types, but they did select different types among years and within breeding intervals (P < 0.05). In years when weather was moderate, woodcock selected young, dense stands of speckled alder (Alnus rugosa) and hardwoods, interspersed with forest openings. Suitable habitat can be maintained by creating an uneven-aged forest managed in even-aged blocks composed of several hardwood species. Managers can now quantify suitable woodcock habitat in a GIS and plan large-scale forest-harvesting strategies using data on several habitat characteristics (e.g., land cover, stand age, stocking density, soil drainage and texture, and aspect).

Book chapter↗
USGS2000

Single paternity of clutches in American Woodcock

Based on behavioral observations, the mating system of American Woodcock has been variously described as monogamous, a dispersed lek, or resource defense polygyny. Males perform elaborate mating displays that attract females to their display sites where copulations occur. We used microsatellite markers, developed for Ruffs (Philomachus pugnax), to assess paternity in American Woodcock. In 3 yr, we collected blood samples from 21 females and broods and 90 males. We found no evidence of multiple paternity within broods; paternity in all broods could be explained by 1 father. For 8 broods, we were able to infer probable fathers from males we sampled in the field. All 8 broods were found close to the singing site of the male or males that matched as possible fathers. Two males may have fathered 2 broods each, suggesting that polygyny may be a component of the woodcock mating system.

Book chapter↗
USGS1998

Outcome of aggressive interactions between American black ducks and mallards during the breeding season

American black duck (Anas rubripes) numbers have declined during the past several decades, while mallards (A. platyrhynchos) have expanded their range eastward. Competitive exclusion of black ducks from wetlands by mallards has been proposed as a principal cause of the decline. We studied a sympatric population of black ducks and mallards in Maine during the early breeding season to document behavior and interactions. We observed 832 aggressive interactions; most (72%) were interspecific. When a choice was available, both species interacted more often with conspecifics than with the other species (P < 0.028). On wetlands occupied simultaneously by both species, numbers of intraspecific interactions initiated by each species were similar (P = 0.470). The proportions of won (initiator displaces recipient of attack), lost (initiator displaced), and "no change" outcomes of these interactions were different (P < 0.001). When black ducks initiated interactions with mallards, black ducks did not lose any interactions and displaced mallards 87.2% of the time; no change occurred during 12.8% of the interactions. When mallards initiated interactions with black ducks, mallards displaced black ducks 63.3% of the time but were displaced by black ducks 15.0% of the time; no change occurred during 21.7% of the interactions. Displacement from wetlands was rare (38 of 229 interspecific interactions) and was equal between species.

Journal of Wildlife Management↗
USGS1998

Brood sizes of sympatric American black ducks and mallards in Maine

The long-term decline of the American black duck (Anas rubripes) population has been attributed to lower productivity of black ducks that might have been excluded from fertile agricultural wetlands by mallards (Anas platyrhynchos). We monitored broods on 53 wetlands in 1993 and on 58 wetlands in 1994 to determine mean brood sizes of black ducks and mallards in forested and agricultural landscapes. Study wetlands were moderately to highly fertile. We monitored 94 black duck broods each year and 46 (1993) and 52 (1994) mallard broods until they reached Class IIc-III (near fledging). No differences existed (P = 0.71) in mean brood size between black ducks (1993: 3.95 ± 0.23; 1994: 4.59 ± 0.24) and mallards (1993: 3.96 ± 0.35; 1994: 5.00 ± 0.43) either year. Brood size for species, however, was different between years (P = 0.014) and among wetland sites (P = 0.001). Mean sizes of broods were larger (P < 0.05) on 2 large impoundment complexes (Lake Josephine and Lake Christina) compared with brood sizes on other wetlands in forested or agricultural landscapes. No differences (P ≥ 0.41) existed between mean Class IIc-III brood sizes of black ducks and mallards, whether species were alone or together on wetlands. Our data document that mallard productivity is similar to that of black ducks where they breed sympatrically in Maine.

Journal of Wildlife Management↗
USGS1997

Survival and fates of staging juvenile, female mallards in the Vermont / Quebec border region

We alternately marked 80 juvenile, female mallards (Anas platyrhynchos), half with transmitters and bands and half with only bands in 1990 and 1991. Survival of radio-marked ducks was monitored daily and then summarized weekly for the periods 31 August - 6 December, 1990 (weeks 5-18) and 11 September - 6 December, 1991) (weeks 6-18). The pattern of survival throughout the staging period did not differ (P = 0.785) between 1990 and 1991. Survival at the end of the staging period (week 18) was low in both years (0.379 in 1990; 0.282 in 1991; and 0.337 for a combined estimate). Only 2.5% (1990) and 7.5% (1991) of the bands of the banded-only sample were recovered. Fates of the ducks were associated with hunter opportunity and are evaluated as related to body mass, flock size and duck behavior as determined from hunter questionnaires.

Book chapter↗
USGS1997

Characteristics of some black duck nest sites in Maine

A standard method for characterizing nest sites and concealment (visibility of orange decoy and percent overhead cover measured by densiometer) was used to obtain characteristics of 36 nest sites of black ducks in Maine, 1978-89. Nest locations were represented by cutover areas (10), islands (6), bogmat (5), emergent meadow (5), emergent wetland (3), stream floodplain (3), hardwood forest (1), conifer forest (1), mixed forest (1) and ephemeral pond (1). Within these locations nests were found in shrub clumps (1), under conifers (6), on hummocks (6), on ericaceous mats (4), under a clump of hardwood trees (4), under woody slash (3), on an emergent herbaceous clump (1), on a boulder (1) and on a muskrat house (1). After excluding 7 nests disturbed by investigators, 22 (76%) of the 29 remaining nests were successful nests. Nests in upland cuts were especially successful (9 of 9) and success was 75 - 100% at most locations, but both nests along stream floodplain were abandoned because of human disturbance. Unsuccessful nests were usually closer to ponds (2.5 times) or streams (6.6 times) and often at land water interfaces, i.e., islands and bogmat. Nests under conifers (5 of 6) and woody slash (3 of 3) usually were successful. The combination of low nesting density and isolation of nests in upland cutover areas (successful nests averaged nearly 3 times farther from roads) seem to influence black duck nest success.

Book chapter↗