Comunities and ecosystems represent aggregates of lower-level orders of
organization - generally, individual species, and populations of those
species. There is considerable research in the Department, primarily
concerned with analysis and understanding of the dynamics of populations,
and how these dynamics might vary within and among species. The following
is an incomplete, but representative list of several 'population' studies
currently under investigation in the department (you should
also
consult web pages
people
associated with research in this
area):
swan project | Atlantic Flyway Tundra Swan Project - Tundra Swans are a long-lived species with relatively low annual recruitment. Since swans breed in remote areas, little is known about their breeding ecology and distribution. In addition, the species is hunted in North Carolina, Virginia, North Dakota, South Dakota, and Montana. Harvest management would be more effective if more was known about their vital rates, migratory patterns, and distribution. Objectives of this study include: to determine the breeding range and migration stopover locations of the Eastern Population (EP) of Tundra Swans, as well as patterns of movement between these areas; to determine fidelity and possible sub-population affiliations of Tundra Swans to Atlantic Flyway wintering locations within years and between subsequent years; to increase precision of survival rate estimates for EP swans; and to determine extent and nature of winter movements of Tundra Swans in relation to habitat use and human disturbance. What makes this project unique is it’s scale and size: hundreds of birds have been marked over most of their Eastern wintering areas, providing a fairly representative sample of the Eastern Population. | | | 
Population response to removal of introduced species | Declines in native fish populations have been associated with the establishment of introduced smallmouth bass (Micropterus dolomieu) populations in the northeastern U.S. Introductions of non-native smallmouth bass have limited the abundance and diversity of native soft-rayed fishes, altered the trophic status of lake trout, and reduced brook trout biomass in Adirondack lakes and other northern waters. This study is designed to demonstrate whether the impact of a widely introduced, non-native fish predator (smallmouth bass) can be reversed in Little Moose Lake, a 200 hectare Adirondack lake. Historical accounts have indicated, and recent research projects have confirmed, that the introduction of smallmouth bass in Little Moose Lake, New York, has had adverse effects on the native fish community, including brook trout, lake trout, pumpkinseed, creek chubs, and common shiners. In the spring of 2000 through the fall of 2001, a total of 19,529 smallmouth bass were removed from Little Moose Lake, predominately by boat electrofishing. Pre-removal population estimates indicate that at least 90% of the adult smallmouth bass population has been removed. Abundance indices (CPUE) of native littoral prey fish and crayfish species have increased following the reduction of the smallmouth bass population. Predation risk, measured by tethered creek chubs, has significantly declined for native littoral prey fishes. Growth and condition of the remaining smallmouth bass have improved, likely a result of lowered intraspecific competition. We expect improved growth and increased abundance of native char and prey species due to reduced predation and interspecific competition by smallmouth bass. | | | 
NY Cooperative Fish
& Wildlife Research Unit | The NY Cooperative Fish & Wildlife Research Unit is one of 30such units established for the purpose of enhancing the management ofthis nation's renewable resources. This we accomplish by: - developing a problem solving research program
- enhancing theeducational and employment opportunities of resource professionals anddegree candidates
- effectively interacting with managementpersonnel, and information and education transfer specialists.
The New York Unit pays particular attention to the resource problems andissues of the Northeastern States with New York as its focal point.With a staff of 3 professionals and a base at Cornell University in theDepartment of Natural Resources we work cooperatively within adepartment structure, but with the option to transcend organizationallines when the need arises. Our efforts are directed not only atmaintaining productive programs in our own areas of interest, but alsoin seeking funds for and coordinating the planning of other research andmanagement faculty/staff at the University and within the N.Y.S.D.E.C.and USFWS Northeast Regional Office. In accomplishing this we are aidedby a select, high quality group of graduate students and researchaffiliates who understand science, people, and the need to grow andproduce in their specialty. | | | 
Snow goose
grazing dynamics | Snow goose grazing dynamics - Snow Geese are a colonially nesting species, with extremely strong natal philopatry amongst females, with strong tradition in their use of nesting and feeding areas. Such breeding and foraging patterns reflects, to a significant degree, a strongly synergistic relationship between herbivorous geese and their principal salt-marsh food plants. Under moderate grazing pressure, there is a positive feedback between grazing intensity and fecal nitrogen deposition and both net above-ground primary production and nitrogen content of food plants. In general, grazing pressure over the course of the breeding season reduces both above-ground forage and the capacity of vegetation to show compensatory growth following grazing. However, the size of the LPB population has nearly doubled in the last 15 years, and high-intensity grazing and early-season grubbing by increased numbers of geese has significantly reduced the annual standing crop of food available at LPB since the beginning of the study. This has had significant long-term negative impacts on both the plants, and the geese. This rapid deterioration of conditions over a comparatively short time span, and the seasonal variation in food supply, creates a behavioral conflict: at the one extreme, birds can remain philopatric to specific nesting or feeding areas, regardless of predictable or unpredictable changes in environmental conditions. | | | 
Harvest of
structured
populations | Optimal harvest of structured populations - Population dynamics are in simplest terms governed by the balance between realized fecundity and recruitment, and mortality (or permanent emigration). For harvested species, this poses the potentially complex problem of determining the harvest practice which, by some criterion, is determined to be "optimal". Optimality decisions are generally derived with reference to the conditions under which population growth is maintained at some sustained equilibrium, either naturally, or through the harvest itself. The calculation of the optimal harvest conditions are often complex, especially where harvesting is variable with respect to time. Many analyses of optimal harvesting assume no age-structure, and continuous time. However, for many populations, this assumption of no age- or stage-structure, and continuous time, is clearly unrealistic. Failure to account for this can contribute significantly to sources of uncertainty, which affects our ability to successfully manage the resource. Preliminary analysis indicates failing to adequately account for structure in the harvested population can lead to unpredictable results in some cases. This result also has significant implications for biodiversity and management of resources, since it allows a flexible framework to assess the relative importance of individuals of a particular age or stage, and in a particular location, to a complex structured system. This is increasingly important in assessing viability of populations in fragmented landscapes. | | | 
Deer control
by sterilization | Control of urban deer by sterilization - The problem of effective control of species regarded by various criteria as overabundant is of increasing concern to managers. Culling and sterilization are generally thought to be to methods of direct management control for nuisance species. Culling (permanent removal of some number of individuals from the population) is clearly the most direct approach to population control. However, it is often unpopular and difficult to implement in many situations. In such cases, non-lethal fertility control has been considered as a more tractable alternative. The impacts of such fertility controls can vary from permanent (which is analogous to demographic death), to transient (where the effects of the contraception are less than the life-time of the treated individual animal). We will be comparing the relative efficacy of both culling and sterilization approaches to population control, using a combination of population models, and field trials. In collaboration with the Cayuga Heights Deer Project, we propose to implement an adaptive management plan to explore the relative utility of sterilization as a control method for overabundant wildlife, using a suburban deer herd as a model system. While clearly the general problem of over-abundance will require a variety of different approaches, the particular problems of control of deer in urban and suburban areas are somewhat specific. | | | 
finch disease dynamics | There is growing evidence that disease can strongly influence the dynamics of a host population and may actually limit population growth under some circumstances. Researchers in DNR are studying an emerging pathogen (Mycoplasma galiscepticum) in a novel host (house finch) as a model system for exploring disease dynamics in wild populations. Their long-term goal is to develop a comprehensive and quantitative model that successfully predicts these patterns at different temporal and spatial scales. To accomplish this we will be using data from (i) intensive capture, mark, recapture study to assess the dynamics of MG in the wild (ii) controlled aviary experiments to study transmission dynamics, immunological effects, and behavior and (iii) monitoring of MG prevalence and house finch abundance across the continent through the House Finch Disease Survey. | | |
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