Physical Sciences and Mathematics Commons^™

Collateral Damage From Agricultural Netting To Open-Country Bird Populations In Thailand, Rongrong Angkaew, Philip D. Round, Dusit Ngoprasert, Larkin A. Powell

School of Natural Resources: Faculty Publications

Nets are used across a wide variety of food production landscapes to control avian pests typically resulting in deaths of entangled birds. However, the impact of nets on bird populations is a human–wildlife conflict that remains mostly unquantified. Here, we examined the scale of netting in the central plains of Thailand, a region dominated by ricefields, among which aquaculture ponds are increasingly interspersed. Nets/exclusion types, number of individual birds and species caught were recorded on 1312 road-survey transects (2-km length × 0.4-km width). We also interviewed 104 local farmers. The transect sampling took place in late- September 2020, and from …

Scaup Depredation On Arkansas Baitfish And Sportfish Aquaculture, Stephen A. Clements, Brian S. Dorr, J. Brian Davis, Luke A. Roy, Carole R. Engle, Katie C. Hanson-Dorr, Anita M. Kelly

USDA Wildlife Services: Staff Publications

Lesser scaup (Aythya affinis) and greater scaup (A. marila), hereafter scaup, consume a variety of aquatic invertebrates, plants, and occasionally small fish. Scaup have foraged on commercial aquaculture farms in the southern United States for decades. However, the types, abundance, and rate of fish exploitation by scaup on baitfish and sportfish farms are not well documented. Thus, information is needed to understand how fish and other foods influence scaup use of aquatic resources, and any potential economic effects of depredation of fish. From November–March in winters 2016–2017 and 2017–2018, we conducted 1,458 pond surveys to estimate …

Distribution And Abundance Of Scaup Using Baitfish And Sportfish Farms In Eastern Arkansas, Stephen A. Clements, Brian S. Dorr, Brian Davis, Luke A. Roy, Carole R. Engle, Katie C. Hanson-Dorr, Anita M. Kelly

USDA Wildlife Services: Staff Publications

Arkansas' bait- and sportfish facilities are commonly used by various piscivorous bird species, including lesser scaup (Aythya affinis) and greater scaup (A. marila) that consume substantial quantities of fish. To mediate this predation, farmers implement extensive bird harassment programs that create additional costs to fish loss, thus research investigating the distribution and abundance of scaup is needed to help farmers allocate their bird harassment efforts more efficiently. In winters 2016–2017 and 2017–2018 we conducted 1,368 pond surveys to investigate pond use by scaup on farms during birds' regular wintering period (i.e., November–March). We used intrinsic and …

Scaup Depredation On Arkansas Baitfish And Sportfish Aquaculture, Stephen A. Clements, Brian S. Dorr, J. Brian Davis, Luke A. Roy, Carole R. Engle, Katie C. Hanson-Dorr, Anita M. Kelly

USDA Wildlife Services: Staff Publications

Lesser scaup (Aythya affinis) and greater scaup (A. marila), hereafter scaup, consume a variety of aquatic invertebrates, plants, and occasionally small fish. Scaup have foraged on commercial aquaculture farms in the southern United States for decades. However, the types, abundance, and rate of fish exploitation by scaup on baitfish and sportfish farms are not well documented. Thus, information is needed to understand how fish and other foods influence scaup use of aquatic resources, and any potential economic effects of depredation of fish. From November–March in winters 2016–2017 and 2017–2018, we conducted 1,458 pond surveys to estimate …

Food Habits Of Wintering Double-Crested Cormorants In The Mississippi Delta, Terrel W. Christie, Brian S. Dorr, J. Brian Davis, Luke A. Roy, Carole R. Engle, Katie Hanson-Dorr, Anita M. Kelly

USDA Wildlife Services: Staff Publications

Given its ubiquity, it is not surprising that agriculture, including fin fish aquaculture, contributes to food webs worldwide and is used by numerous wildlife for foraging and meeting other needs. Double-crested Cormorants (Phalacrocorax auritus) impact United States commercial aquaculture and are considered the primary avian predator in catfish (Ictalurus spp.) aquaculture facilities in the Mississippi Delta. Recent changes in aquaculture practices, regulatory policies, and decreased overall hectares in production prompted this study that assessed cormorant consumption of catfish in relation to their night roosts through surveys and diet analysis. Cormorants were collected from night roosts from October …

Piscivorous Bird Use Of Aquaculture And Natural Water Bodies In Mississippi, Paul C. Burr, Jimmy I. Avery, Garrett M. Street, Bronson K. Strickland, Brian S. Dorr

USDA Wildlife Services: Staff Publications

Double crested cormorants (Phalacrocorax auritus) and great egrets (Ardea alba) have an extensive history of human wildlife conflict with the aquaculture industry of western Mississippi, USA, due to

their depredation of cultured catfish (Ictalurus spp.). Although aquaculture is abundant, western Mississippi also contains naturally occurring water bodies that offer alternative forage opportunities to these species. How cormorants or egrets distribute themselves among these 2 foraging options is unknown, but it has been generally assumed each species uses aquaculture disproportionately more because of the high density of available prey. To test this assumption, we surveyed these …

Historic And Contemporary Use Of Catfish Aquaculture By Piscivorous Birds In The Mississippi Delta, Paul C. Burr, Jimmy L. Avery, Garrett M. Street, Bronson K. Strickland, Brian S. Dorr

USDA Wildlife Services: Staff Publications

Piscivorous birds are the primary source of catfish (Ictalurus spp.) depredation at aquaculture facilities in northwestern Mississippi. Of particular concern is the Double-crested Cormorant (Phalacrocorax auritus), which can cost aquaculture producers millions of dollars annually through the depredation of cultured fish. Historical research conducted in the early 2000s estimated cormorant use of aquaculture ponds in the region, but aquaculture area has decreased by more than 70% since those estimates were made. With less aquaculture available, we predicted cormorant densities on aquaculture would be greater today than historically. Applying a similar methodology as in historical studies, we used …

Estimating Waterbird Abundance On Catfish Aquaculture Ponds Using An Unmanned Aerial System, Paul C. Burr, Sathishkumar Samiappan, Lee A. Hathcock, Robert J. Moorhead, Brian S. Dorr

USDA Wildlife Services: Staff Publications

In this study, we examined the use of an unmanned aerial system (UAS) to monitor fish-eating birds on catfish (Ictalurus spp.) aquaculture facilities in Mississippi, USA. We tested 2 automated computer algorithms to identify bird species using mosaicked imagery taken from a UAS platform. One algorithm identified birds based on color alone (color segmentation), and the other algorithm used shape recognition (template matching), and the results of each algorithm were compared directly to manual counts of the same imagery. We captured digital imagery of great egrets (Ardea alba), great blue herons (A. herodias), and doublecrested cormorants (Phalacrocorax auritus) on aquaculture …

Using Unmanned Aerial Vehicles For Bird Harassment On Fish Ponds, Ciera A. Rhoades, Peter J. Allen, D. Tommy King

USDA Wildlife Services: Staff Publications

The effects of aquaculture decline on piscivorous birds in the Mississippi Delta concern catfish farmers, with possible increases in fish loss and disease transmission. Piscivorous birds quickly habituate to most current methods of harassment (loud noises and visual disturbances) leading to increased depredation and disease. Our study was designed to test the efficacy of using unmanned aerial vehicles (UAVs) to effectively control piscivorous birds at fish farms. We hypothesized that a UAV would be more efficient at reducing the number of fish-eating birds on fish ponds than current forms of harassment. We conducted pre-treatment bird surveys, harassment observations, and post-treatment …

Increased Abundance And First Breeding Record Of The Neotropic Cormorant (Phalacrocorax Brasilianus) On The Alluvial Plain Of Mississippi, Katie C. Hanson, Travis L. Devault, Stephen J. Dinsmore

USDA Wildlife Services: Staff Publications

Phalacrocorax brasilianus (Neotropic Cormorant) has been observed with increasing frequency in the alluvial plain (Delta region) of Mississippi. In the past 6 years, 22 individuals have been observed in 20 separate sightings during spring and summer. These sightings have occurred at breeding colonies of other colonial waterbirds and commercial aquaculture facilities of Ictalurus punctatus (Channel Catfish). Two sexually mature Neotropic Cormorants have been collected at a colonial waterbird breeding colony near the Mississippi River in the western Delta region among flocks of Phalacrocorax auritus (Double-crested Cormorants). Twice during the summer of 2008, confirmed nesting of Neotropic Cormorants were documented in …

Evaluation Of Aerial Cluster Sampling Of Double-Crested Cormorants On Aquaculture Ponds In Mississippi, Brian S. Dorr, Loren W. Burger Jr., Scott C. Barras

USDA Wildlife Services: Staff Publications

Concern over increasing numbers of double-crested cormorants (Phalacrocorax auritus) and their impacts on channel catfish (Ictalurus punctatus) aquaculture has resulted in increased need for quantitative information to develop and evaluate depredation management efforts. We evaluated aerial surveys in a stratified cluster sampling (SCS) design to estimate and monitor abundance of cormorants on catfish aquaculture ponds in the Yazoo River Basin of Mississippi, USA (hereafter Yazoo Basin). Twice monthly abundance estimates and coefficient of variation during winter averaged 8,128 (n = 29, SE = 1,233) and 33% (n = 29, SE = 0.02), respectively. Counts of cormorants …

Comparison Of Sampling Strategies To Estimate Abundance Of Double-Crested Cormorants In Western Mississippi, Aaron T, Pearse, Brian S. Dorr, Stephen J. Dinsmore, Richard M. Kaminski

USDA Wildlife Services: Staff Publications

We compared 2 sampling strategies designed to estimate abundance of double-crested cormorants (Phalacrocorax auritus, hereafter cormorants) on aquaculture ponds in western Mississippi. Cormorants are a major predator of cultured channel catfish (lctalurus punctatus) in this region; thus, estimating cormorant abundance is needed to better determine their economic impact We independently designed a species-specific survey (i.e., cluster sampling) and a general survey (i.e., transect sampling) based on robust probability sampling theory to estimate abundance of this target population. During winters 2002-2003 and 2003-2004, we conducted 8 pairs of surveys and compared estimates of cormorant abundance and associated …

Comparison Of Sampling Strategies To Estimate Abundance Of Double-Crested Cormorants In Western Mississippi, Aaron T. Pearse, Brian S. Dorr, Stephen J. Dinsmore, Richard M. Kaminski

Human–Wildlife Interactions

We compared 2 sampling strategies designed to estimate abundance of double-crested cormorants (Phalacrocorax auritus, hereafter cormorants) on aquaculture ponds in western Mississippi. Cormorants are a major predator of cultured channel catfish (Ictalurus punctatus) in this region; thus, estimating cormorant abundance is needed to better determine their economic impact. We independently designed a species-specific survey (i.e., cluster sampling) and a general survey (i.e., transect sampling) based on robust probability sampling theory to estimate abundance of this target population. During winters 2002–2003 and 2003–2004, we conducted 8 pairs of surveys and compared estimates of cormorant abundance and associated …

Interactions Between The American White Pelican And Aquaculture In The Southeastern United States: An Overview, D. Tommy King

USDA Wildlife Services: Staff Publications

The eastern metapopulation of the American White Pelican ( Pelecanus erythrorhynchos ) breeds mainly in the Northern Great Plains, migrates through the Great Plains and along the Mississippi River and winters in the lower Mississippi River Valley and along the Gulf of Mexico. The production of farm-raised Channel Catfish ( Ictalurus punctatus ) in the southeastern United States has increased dramatically in the last 25 years. In 1990, U.S. Department of Agriculture Wildlife Services offices in Arkansas, Louisiana and Mississippi began receiving complaints concerning the foraging of pelicans in commercial Channel Catfish ponds. Because of the relatively shallow depth and …

The Role Of Research In Expanded Regional Management Of Double-Crested Cormorants, Scott C. Barras, Mark E. Tobin

USDA Wildlife Services: Staff Publications

The number of double-crested cormorants (Phalacrocorax auritus) breeding in the Great Lakes states and provinces has increased during recent decades. Their abundance and foraging habits have thrust this species into conflict with the aquaculture industry and fisheries interests. The U. S. Fish and Wildlife Service proposed a change in the management of double-crested cormorants recently to alleviate these conflicts, especially with aquaculture, natural resources, and federal fish hatcheries. Research activities should be an integral component of these expanded efforts to manage cormorants, including further investigations on cormorant impacts to the aquaculture industry and evaluations of the added benefits …

Low Mitochondrial Dna Variation In Double-Crested Cormorants In Eastern North America, Juliann L. Waits, Michael L. Avery, Mark E. Tobin, Paul L. Leberg

USDA Wildlife Services: Staff Publications

Double-crested Cormorant (Phalacrocorax auritus) numbers are increasing throughout eastern North America. We compared variation for five portions of mtDNA to determine if genetic differences existed among portions of the breeding range that would need to be considered when formulating management programs. Sequences for four mtDNA regions were identical across sample locations; frequencies of two haplotypes of the mitochondrial Control Region were similar across sampling locations. There is no evidence of restricted gene flow among breeding areas, or between subspecies with different migratory patterns.

Low Mitochondrial Dna Variation In Double-Crested Cormorants In Eastern North America, Juliann L. Waits, Michael L. Avery, Mark E. Tobin, Paul L. Leberg

USDA Wildlife Services: Staff Publications

Double-crested Cormorant (Phohoiornx audus) numbers are increasing throughout eastern North America. We compared variation for five portions of mtDNA to determine if genetic differences existed among portions of the breeding range that would need to be considered when formulating management programs. Sequences for four mtDNA regions were identical across sample locations: frequencies of two haplotpes of the mitochondria1 Control Region were similar across sampling locations. There is no evidence of restricted gene flow among breeding areas, or between subspecies with different migratory patterns.

Wading Bird Management And Research On North American Aquaculture Facilities, Brian Dorr, Jimmy D. Taylor Ii

USDA Wildlife Services: Staff Publications

Aquaculture in North America varies geographically with respect to species cultured, annual production, size, complexity, and spatial arrangement of facilities. Species assemblages of predacious birds using aquaculture facilities also vary with many of these industry characteristics. Wading birds are highly adaptable, relatively ubiquitous throughout the aquaculture industry, and often associated with fish depredation problems at aquaculture facilities. Suitability of information regarding the impacts of wading birds to aquaculture varies dramatically by depredating species and industry sector. Great blue herons (Ardea herodias) cause considerable depredation losses on trout aquaculture in the Northeast, and current research suggests that little blue …

Double-Crested Cormorant Impacts To Commercial And Natural Resources, Jimmy D. Taylor Ii, Brian S. Dorr

USDA Wildlife Services: Staff Publications

The North American population of double-crested cormorants (Phalacrocorax auritus) has increased at an annual rate of 6.8% since 1966, with regional growth exceeding 20%/year since 1990 in Ontario and states bordering the Great Lakes. Population numbers, though operating under biological carrying capacity, have exceeded acceptance capacity with several wildlife stakeholder groups throughout Canada and the United States. Stakeholder concerns predominantly focus around social, ecological, and economic values associated with habitat destruction, changes in recreational fisheries, and loss of production at aquaculture facilities. We describe perceptible impacts to these commercial and natural resources, and discuss current research and management …

Effect Of Roost Harassment On Cormorant Movements And Roosting In The Delta Region Of Mississippi, Mark E. Tobin, D. Tommy King, Brian S. Dorr, Scott J. Werner, David S. Reinhold

USDA Wildlife Services: Staff Publications

Double-crested Cormorant (Phalacrocorax auritus) predation on Channel Catfish (Ictalurus punctatus) at commercial farms has been estimated to cost the Mississippi aquaculture industry approximately $5 million annually to replace consumed fingerlings. In 1997, catfish producers assumed responsibility for the dispersal of cormorants in night roosts in the eastern (interior) delta region of Mississippi, where catfish farms are concentrated. We documented movements of 50 cormorants marked with radio transmitters in the delta region from January through March 1997. We obtained 161 post-capture day locations and 176 post-capture night roost locations. Cormorants that were harassed at their night roost …

Great Egret Preference For Catfish Size Classes, Scott J. Werner, Mark E. Tobin, Paul B. Fioranelli

USDA Wildlife Services: Staff Publications

Several species of fish-eating birds are commonly observed near aquaculture facilities in the southern United States. An understanding of the relationships between these birds and specific commodities is needed to interpret and manage bird impacts to aquacultural production. We conducted two foraging experiments to evaluate the preference o f Great Egrets (Ardea alba) for three specific size classes of Channel Catfish (Zctalurus punctatus). During six no-choice feeding trials, egrets consumed significantly more small (7.5-10 cm) fingerlings than medium (13- 18 cm) or large (23-23 cm) catfish. Egrets captured 19 large catfish, and ingested only two, even …

Daily Activity Budgets And Population Size Of American White Pelicans Wintering In South Louisiana And The Delta Region Of Mississippi, D. Tommy King, Scott J. Werner

USDA Wildlife Services: Staff Publications

Twenty-one American White Pelicans (Pelecanus erythrorhynchos) were captured and fitted with radio-transmitters in South Louisiana and the delta region o f Mississippi during the winter and early spring of 1994-1997. The pelicans were monitored to determine their daily activity budgets while using different habitats such as catfish ponds, crawfish ponds, rivers, lakes, and bayous. Pelicans foraging at catfish ponds spent about 4% of their day foraging and 96% loafing, while pelicans foraging in other habitats spent about 28% of their day foraging and 72% loafing. For an individual bird, the mean number of foraging sessions per day was …

Bada Bang, Bada Boom: Dispersal Of Fall Migrating Cormorants To Protect Sportfish On Oneida Lake, New York, Richard B. Chipman, Milo Richmond, Justin T. Gansowski, Ken J. Preusser, Douglas L. Stang, Jeremy Coleman, Dennis Slate

Wildlife Damage Management Conference Proceedings

The interior population of double-crested cormorants (Phalacrocorax auritus) continues to increase. As a result, conflicts between human interests and cormorants have intensified. The impacts of nesting, roosting, and migrating cormorants include predation at aquaculture facilities, interspecific competition with rare species including common terns {Sterna hirundo), and impacts to private property. In addition, heightened public and scientific debate regarding cormorant impacts on sportfish has accelerated the need for effective, socially acceptable methods for managing local conflicts. In 1998 and 1999, USDA, APHIS, Wildlife Services; the New York State Department of Environmental Conservation; and USGS, New York Fish and Wildlife Research Cooperative …

Double-Crested Cormorant Satellite Telemetry: Preliminary Insight, Scott J. Werner, D. Tommy King, David E. Wooten

Wildlife Damage Management Conference Proceedings

Migratory paths of North American waterbirds have traditionally been evaluated by relocating birds banded as nestlings. Although over 8,000 banded Double-crested Cormorants (Phalacrocorax auritus) have been recovered in North America since 1923, the movements of wintering and breeding cormorants remain poorly understood. We initiated a satellite telemetry study to determine the annual and regional distributions of 25 cormorants (in each of two study years) captured near primary aquaculture areas in Alabama, Arkansas, Louisiana, and Mississippi. Preliminary data suggest that cormorants generally remained near aquaculture facilities where they were captured, marked, and released. Two cormorants, however, emigrated from primary aquaculture areas …

Cormorant Depredation Losses And Their Prevention At Catfish Farms: Economic Considerations, James F. Glahn, Scott J. Werner, Terry Hanson, Carole R. Engle

Human Conflicts with Wildlife: 2002 Symposium

Although several piscivorous birds are involved in depredation conflicts with southern aquaculture, the double-crested cormorant causes some of the most widespread and significant problems to catfish, the dominant industry. Unlike other agriculture commodities, catfish losses due to predation cannot be directly measured, so we review several approaches taken to estimate these losses. Although these approaches are valid for predicting the costs of simply replacing these fish at the time of predation, they have been criticized because they failed to consider the functional relationships between predation and output parameters at harvest. Recent controlled experiments are reviewed that confirm previous estimates of …

Research And Management Of Bird Depredations At Catfish Farms, Mark E. Tobin

Proceedings of the Eighteenth Vertebrate Pest Conference (1998)

Depredations by fish-eating birds are a major constraint on production at commercial catfish facilities in the southeastern United States. A recent survey of catfish farmers estimated total losses due to direct predation by birds and costs associated with employing preventive measures at $17 million, or 4% of national sales. In 1988, the U.S. Department of Agriculture's (USDA) National Wildlife Research Center (NWRC) established a research station in Mississippi to develop more effective methods for reducing the impact of birds on southeastern aquaculture farms. This paper describes the impact of double-crested cormorants (Phalacrocorax auritus, DCCO) on the catfish industry, …

Development Of A Double-Crested Cormorant Damage Management Plan For The Southeastern United States, Keith J. Andrews, Pete Poulos, Charles (Bo) Sloan, Jerrold L. Belant, Paige G. Ross, Paul Debow

Eighth Eastern Wildlife Damage Management Conference (1997)

In response to needs within the aquaculture industry to alleviate increasing depredation by double-crested cormorants (Phalacrocorax auritus), the U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, in conjunction with Federal, State, and Canadian wildlife and fisheries agencies, the aquaculture industry, and other wildlife professionals, is developing the framework for a comprehensive cormorant damage management program that uses an integrated wildlife damage management approach. This cooperative effort will produce a meaningful, mutually beneficial program that will reduce the effects of cormorants on aquaculture and sport and commercial fisheries, improve understanding of cormorant biology, and avert …

Depredation Of Catfish By Double-Crested Cormorants At Aquaculture Facilities In Oklahoma, Robert L. Simmonds Jr., Alexander V. Zale, David M. Leslie Jr.

Great Plains Wildlife Damage Control Workshop Proceedings

Oklahoma has about 324 ha of surface water in catfish (Ictalurus spp.) production. The state also supports a large number of migrating and wintering piscivorous birds, particularly double-crested cormorants (Phalacrocorax auritus). To address concerns of aquaculture facility operators regarding loss of fish to cormorants, we asked 11 operators to conduct regular counts of piscivorous birds at each facility. These data were used to determine factors affecting cormorant density at facilities and to estimate amount of catfish lost to cormorant depredation. Cormorant density (birds/ha/day) was positively correlated with surface area of water in production at facilities <10 ha (r = …