Search USGSSearch

Geology topics

Daniel G. McAuley

Publications and source records attributed to Daniel G. McAuley.

12 recordsLinked to original sources

Anatidae brood records in Maine during studies of Anas rubripes (American black duck), 1977–94

This report describes a compilation of brood observations for Anatidae species breeding in Maine during an 18-year period (1977–94) that were made by the U.S. Geological Survey’s Patuxent Wildlife Research Center while it was operated by the U.S. Fish and Wildlife Service. During four focused studies, variables affecting the declining Anas rubripes (Brewster, 1902) (American black duck, hereafter black duck) population were assessed. Broods were observed on seven geographical study sites within four study areas located in three of Maine’s five biophysical regions. For combined studies, 168 wetlands were monitored for broods. The 1,907 recorded broods were distributed among study areas: 185 in Dixmont, 241 in Cherryfield and Beddington, 411 in Moosehorn, Baring Unit and Edmunds Unit, and 849 in Aroostook County, Agricultural and Forested sites. Additionally, 221 broods were recorded in the 117-hectare Downing Bog wetland at the Cherryfield site during annual evening visits made between 1985 and 1991. Twelve Anatidae species, mostly black duck (676), Aix sponsa (Linnaeus, 1758) (wood duck; 265), Aythya collaris (Donovan, 1809) (ring-necked duck; 246), and Lophodytes cucullatus (Linnaeus, 1758) (hooded merganser; 163) were observed. Only 139 broods of Anas platyrhynchos (Linnaeus, 1758) (mallard) were found; all but 9 broods were at the Aroostook County, Agricultural site. Branta canadensis (Linnaeus, 1758) (Canada goose) broods were found at the Aroostook County, Agricultural site (58) and Moosehorn, Baring Unit (97). For the combined studies, 468 of 676 (69.2 percent) of black duck broods reached fledging age (Class IIc-III), whereas 93 of 139 (66.9 percent) of mallard broods reached fledging age. Black ducks used predominantly palustrine, emergent wetland; palustrine, forested wetland; and palustrine, scrub-shrub wetland. Of the 134 mallard broods observed at the Agricultural and Forested sites in Aroostook County, 130 (97.0 percent) were observed at the Agricultural site and 93 (71.5 percent) of them were recorded on two palustrine and two lacustrine, unconsolidated bottom class wetlands. Mean size of black duck, wood duck, and ring-necked duck broods in this report were similar to those reported from historic Maine data.

Maine

A full annual cycle modeling framework for American black ducks

American black ducks ( Anas rubripes ) are a harvested, international migratory waterfowl species in eastern North America. Despite an extended period of restrictive harvest regulations, the black duck population is still below the population goal identified in the North American Waterfowl Management Plan (NAWMP). It has been hypothesized that density-dependent factors restrict population growth in the black duck population and that habitat management (increases, improvements, etc.) may be a key component of growing black duck populations and reaching the prescribed NAWMP population goal. Using banding data from 1951 to 2011 and breeding population survey data from 1990 to 2014, we developed a full annual cycle population model for the American black duck. This model uses the seven management units as set by the Black Duck Joint Venture, allows movement into and out of each unit during each season, and models survival and fecundity for each region separately. We compare model population trajectories with observed population data and abundance estimates from the breeding season counts to show the accuracy of this full annual cycle model. With this model, we then show how to simulate the effects of habitat management on the continental black duck population.

Natural Resource Modeling

Survival of female mallards along the Vermont-Quebec border region

Understanding effects of location and timing of harvest seasons on mortality of ducks and geese from hunting is important in forming regulations that sustain viable waterfowl populations throughout their range. During 1990 and 1991 we alternately marked 80 hatching year (HY), female mallards along the Vermont–Quebec border; half with radio-transmitters and bands and half with only aluminum leg bands. We monitored radio-marked ducks daily and recorded survival status weekly for 15 weeks from August until December each year. Mallard mortalities began 25 September when the hunting season opened in the Province of Quebec, Canada. Overall survival of mallards at week 10 did not differ between years (0.51 in 1990 vs. 0.43 in 1991) or differ from that of HY American black ducks (0.44 females, 0.42 males) based on proportional hazard analysis in a Bayesian framework. The mortality rates for mallards from hunting (0.47) and causes unrelated to hunting (0.06) were similar between years and to those rates for HY black ducks at that same site. Hunter harvest accounted for most of the mortality recorded during this study and illegal feeding (i.e., baiting) at sites just before and during the hunting season was observed. Females with lower body condition index had greater mortality rates; a 1-standard-deviation increase in condition index would reduce mortality hazard by about 29%. Management options that may increase mallard survival in the area include lowering daily bag limit in Quebec and suspending split hunting seasons in Vermont that increase harvest, delaying opening date of hunting in Quebec to allow for increased body condition before hunting season opens, and improving enforcement of baiting restrictions.

Quebec, Vermont

The role of pH in structuring communities of Maine wetland macrophytes and chironomid larvae (Diptera)

Aquatic vascular plants, or macrophytes, are an important habitat component for many wetland organisms, and larvae of chironomid midges are ubiquitous components of wetland fauna. Many chironomids are primary consumers of algae and detritus and form an essential energetic link between allochthonous and autochthonous primary production and higher trophic levels, while others are predators and feed on smaller invertebrates. Live macrophytes serve mostly as habitat, whereas plant detritus serves as both habitat and as a food source. Assemblages of macrophytes and chrinomid larvae were surveyed in ten Maine wetlands, five with low pH (<5.0) and five with high pH (>5.5), and explained in terms of physical and chemical habitat variables. Macrophyte richness was significantly greater, and richness of chironomid larvae was lower, in low pH wetlands. There was no difference in chironomid abundance related to pH. However, community structure was related to pH, suggesting that competitive dominance of a few taxa was responsible for lower richness in low pH wetlands, whereas competition was weaker in high pH wetlands, making coexistence of more chironomid taxa possible. An examination of individual chironomid taxa by stepwise multiple regression showed that distribution of most taxa was controlled by water chemistry variables and macrophyte habit (i.e., floating, submergent).

Maine

Effects of hunting on survival of American woodcock in the Northeast

Numbers of American woodcock ( Scolopax minor ) males counted on the annual singing ground survey (SGS) have declined over the last 35 years at an average rate of 2.3% per year in the Eastern Region and 1.8% per year in the Central Region. Although hunting was not thought to be a cause of these declines, mortality caused by hunters can be controlled. Furthermore, there has been no research on effects of hunting mortality on woodcock populations at local and regional levels on the breeding grounds. We used radiotelemetry to determine survival rates and causes of mortality for 913 woodcock captured during fall 1997–2000 on 7 areas in Maine, New Hampshire, Pennsylvania, and Vermont, USA. Three of 7 sites were closed to hunting. For all sites and all years combined, 176 woodcock died, and 130 were censored, of which 39 were censored mortalities. Predation was the major ( n = 134, 76%) cause of mortality. Mammals accounted for 56% of the predation, raptors accounted for 25%, and 19% was attributed to unknown predators. On hunted sites, 36% of the total mortality ( n = 102) was caused by hunting, 63% by predation, and 1 bird starved. Kaplan-Meier survival curves did not differ between hunted and non-hunted sites among years ( P = 0.46). Overall, point estimates of survival did not differ ( P = 0.217) between hunted (SR = 0.636, SE = 0.04) and nonhunted sites (SR = 0.661, SE = 0.08). We modeled hazard rates from hunting and natural mortality events using program MARK. Akaike's Information Criterion supported using a model with common constant hazards from both hunting and natural causes for groups of sites. Groupings of sites for hazard rates from natural causes were not influenced by whether a site was hunted or not. Models detected no effects of woodcock age and sex ( P = 0.52) on survival. Proportional hazards models comparing hunted and nonhunted sites found no effects of age and sex ( P = 0.45), interactions of age, sex, capture weight, and bill length ( P ≥ 0.269). Our data suggest that current hunting regulations are not causing lower survival of woodcock.

Maine, New Hampshire, Pennsylvania, Vermont

Habitat characteristics of American woodcock nest sites on a managed area in Maine

We measured characteristics of habitat near 89 nests of American woodcock ( Scolopax minor ) and 100 randomly selected points on Moosehorn National Wildlife Refuge, Calais, Maine, an area managed for woodcock. At nest sites, basal area was lower ( P < 0.001), densities of deciduous saplings were greater ( P < 0.001), densities of coniferous saplings were lower ( P = 0.001), densities of shrub stems were greater ( P = 0.002), and height of trees was shorter ( P = 0.001) than at random sites. Nest sites were closer to openings ( P < 0.001) than were random sites. Nests were in 15 cover types. The aspen ( Populus spp.), tamarack ( Larix laricina ), and alder ( Alnus rugosa ) types were used as nest sites more often than expected in relation to habitat types available at random sites ( P < 0.001). Fifty-eight percent ( n = 89) of nests were in stands of aspen, 11% in alder or tamarack, and 10% in mature second-growth gray birch ( Betula populifolia ) and red maple ( Acer rubrum ). Forty-four percent (n = 89) of the nests were in clearcuts <10 years old. Habitat characteristics around sites of first nests were not different among years ( P > 0.05) or between sites of successful nests and nests destroyed by predators, although the large variances of the variables reduced our power to detect differences. Habitat around sites of renests differed from sites of first nests. Sites around first nests had lower basal area of dead trees ( P = 0.05) and higher stem densities of aspen ( P = 0.03) and cherry saplings ( P = 0.001), and viburnum ( P = 0.05), while renest sites had taller trees ( P = 0.02). The change from nest sites in areas dominated by alders and tree-size gray birch used in 1977-80 to sites dominated by sapling trees, especially aspen, used during 1987-90 suggests that woodcock in the expanding population at the refuge are selecting nest sites created by habitat management since 1979.

Maine

Survival of postfledging female American black ducks

We equipped 106 hatching-year (HY), female, black ducks ( Anas rubripes ) with transmitters during 1985-87 and monitored survival from late August to mid-December on a lightly hunted area on the Maine-New Brunswick border. The 1985-87 estimate of survival (hunting losses included) was 0.593, and when losses from hunting were censored it was 0.694. Survival in August-September was 0.987; by 31 October survival declined to 0.885, and by 30 November it was 0.718. Most nonhunting mortality was caused by predators (21/41, 53.2%); there were 14 deaths (34.1%) from mammals or unknown predators and 7 (17.1%) from raptors. Hunting caused 13 (31. 7%) deaths. Ducks with lowest mass had the lowest survival. The estimate of survival for postfledging female black ducks, when multiplied with interval survival rates for hunting, winter, and breeding periods, produced an annual survival estimate of 0.262, about 12% lower than that (0.38) based on analysis of banding data.

Maine

Habitat use by postfledging American black ducks in Maine and New Brunswick

We examined habitat use by 112 postfledging American black ducks ( Anas rubripes ) in eastern Maine and southwestern New Brunswick from September through early December of 1985, 1986, and 1987. Ducks were captured on Moosehorn National Wildlife Refuge (NWR), Maine. Palustrine Emergent Wetland was the most preferred habitat type. Riverine habitats were avoided in September, but were used more than, or in proportion to, their availability in November as ice formed on lentic habitats. Black ducks used a greater variety of habitat types during the day than at night, when ducks used mostly large (>30 ha) Emergent Wetland marshes. Managed impoundments of Moosehorn NWR were the most used wetlands (66% of all diurnal, 90% of all nocturnal locations). For black duck management, we propose maintaining large (30-50 ha) marshes containing dense emergent vegetation that are located near a complex of diverse wetland types.

Maine

Survival of juvenile ring-necked ducks on wetlands of different pH

Brood and duckling survival of ring-necked ducks ( Aythya collaris ) was examined in relation to wetland water chemistry in eastcentral Maine during 1983-85. Daily survival rates (DSR) of broods and ducklings were determined for 381 ducklings from 64 broods by counts of each brood at 6-10-day intervals during broodrearing. Twelve of 64 females lost entire broods. Only 176 of 381 (46%) ducklings survived to fledge. Brood survival for the 45-day rearing period was 0.7731; duckling survival was 0.3707. Young ducklings ( ≤ 24 days) survived at a lower rate (0.9750/day) than older ( ≥ 25 days) ducklings (0.9818/day) ( P = 0.002). Survival rates of broods and ducklings did not differ among wetlands of high and low alkalinities. Brood survival did not differ among wetlands of different pH, but DSR of ducklings was lower (0.9763/day) on low-pH (<6.0) wetlands than on high-pH ( ≥ 6.1) wetlands (0.9816/day) ( P = 0.049). Class IIb-III (25-45 days old) ducklings from the lowest-pH wetlands(<5.5) had the lowest DSR (0.9752) while Class IIb-III ducklings from the highest-pH wetlands (>6.5) had the highest DSR (0.9856) ( P = 0.009).

Maine

Foods of juvenile ring-necked ducks: Relationship to wetland pH

Foods of 37 juvenile ring-necked ducks ( Aythya collaris ) from 16 different wetlands were examined in eastcentral Maine in 1983-85. Invertebrates made up 70% aggregate dry weight (100% occurrence) of the foods of Class Ia-IIa ( ≤ 24 days old) ducklings and 32% (86% occurrence) of Class IIb-III ( ≥ 25 days old) ducklings. These percentages may be as high as 85% for Ia-IIa ducklings and 47% for IIb-III ducklings after adjusting for insect sclerites. Ducklings ate invertebrates from 44 taxa and seeds or fibers from 23 plant taxa. Freshwater sponges (Porifera) were the most important invertebrate and constituted 23% of the foods of all ducklings. Seeds of pondweeds ( Potamogeton spp.) were the most important plant foods. Diets of ducklings from high-pH ( ≥ 6.1) wetlands were more diverse (t = 2.54, P = 0.021) than those from low-pH (<6.1) wetlands and consisted of 33 invertebrate taxa. Only 17 taxa occurred in ducklings from low-pH ponds. Class Ia-IIa ducklings from high-pH wetlands ate more invertebrates (77%) than ducklings from lower-pH wetlands (61%), although the difference was not significant (P = 0.21). Sponges made up the largest percentage of the diets and occurred in similar amounts in high- (34%) and low- (31.5%) pH wetlands.

Maine

Woodcock singing-ground counts and habitat changes in the northeastern United States

Aerial photography from the late 1960's and the late 1970's was used to study habitat changes along 78 American woodcock ( Scolopax minor ) singing-ground routes in 9 northeastern states. The most noticeable changes were declines in the amount of abandoned field, cropland, shrubland, and field/pasture. The amount of land in the urban/industrial type increased 33.4% from the late 1960's to the late 1970's. We examined relationships between the woodcock call-count index and habitat variables using multiple-regression techniques. The abundance of calling male woodcock was positively correlated with the amount of abandoned field and alder ( Alnus sp.) and negatively correlated with the amount of urban/industrial type. However, only the change in the urban/industrial type was significantly (P < 0.05) related to the change in the call-count index. Urban/industrial area increased, whereas the call-count index declined on average in our sample of routes by 1.4 birds/route (40.5%).

Connecticut, Maine, Maryland, Massachusetts, New H