Saturday, February 22, 2014

Submitted Comments - Draft Management Plan for Mute Swans

February 20, 2014
NYSDEC Bureau of Wildlife
Swan Management Plan
625 Broadway
Albany, NY 12233

The League of Humane Voters of New Jersey and the Animal Protection League of New Jersey oppose the Draft Management Plan for Mute Swans.

The alleged case against the Mute Swan is largely ideological and predicated on "potential," not proved, impacts.

The plan is speculative. Proffered justification for eliminating an enormously popular and largely inoffensive 
species within New York boundaries entails possible scenarios, inconclusive and/or out-of-context science, and exaggerated impacts on humans and air travel (“exhibited,” “potential”).

The Bureau of Wildlife’s singling out of the Mute Swan is extraordinarily selective. The degree of destruction and disturbance caused by shooting --an activity avidly supported by the few, “partnered” interests behind the Mute Swan Management Plan -- to waterfowl and habitat is demonstrably far greater and more pernicious than any caused by Mute Swans. Hunting is a “primary threat” to birds within the National Wildlife Refuge System and elsewhere. Categorized “destruction and disruption of refuge wildlife and habitat” includes: 
  1. Direct mortality: immediate, on-site death of an animal;
  2. Indirect mortality: eventual, premature death of an animal caused by an event or agent that predisposed the animal to death;
  3. Lowered productivity: reduced fecundity rate, nesting success, or reduced survival rate of young before dispersal from nest or birth site;
  4. Reduced use of refuge: wildlife not using the refuge as frequently or in the manner they normally would in the absence of visitor activity;
  5. Reduced use of preferred habitat on the refuge: wildlife use is relegated to less suitable habitat on the refuge due to visitor activity; and
  6. Aberrant behavior/stress: wildlife demonstrating unusual behavior or signs of stress that are likely to result in reduced reproductive or survival rates.
The agency is not forthcoming in acknowledging its desire to eliminate perceived competition with potential “game” birds, primarily the Trumpeter Swan. In the West, open seasons for Trumpeter were underway even as restocking programs were in progress. Under the rubric of conservation, the Bureau has instead fashioned a problem to suit a pre-determined, and final, solution.

The New York State Department of Environmental Conservation fact sheet for “shooting preserves,” defined as “[W]holly enclosed lands or an entire island where the release and taking of propagated domestic game birds by shooting is allowed from September 1April 15,” lists swans under “domestic game birds bred in captivity.”


Wildlife, including the Mute Swan, is a public trust. The crude elimination of an estimated 2,200 swans by beheading, shooting, gassing, and egg-addling for the purpose of providing more “game” species for a narrow interest group and Bureau clients – or to suit a disputed, ideological fashion of the moment -- violates that trust.


According to the Bureau of Wildlife:

Mute Swans are most numerous on Long Island and in the lower Hudson Valley, but have expanded their 
range in recent years, especially around Lake Ontario. Mute swans can cause a variety of problems, 
including exhibiting aggressive behavior towards people, destruction of submerged aquatic vegetation, displacement of native wildlife species, degradation of water quality and potential hazards to aviation.

This draft management plan supports actions by DEC to eliminate free-ranging mute swans from New York by 2025, while allowing responsible ownership of these birds in captivity. DEC recently proposed listing mute swan as a "prohibited species" under new Invasive Species regulations, which would prohibit the sale, importation, transport, or introduction of this species in New York.

Lack of Coherence; Unanswered Questions

Canadian naturalist, bird expert, artist and writer Barry Kent MacKay is well known and respected. His Nature Trail column was published weekly in the Toronto Star for a period of 25 years. His writings and articles have appeared in numerous publications such as Birds of the Wild; Defenders; BirdWatchers’ Digest; Seasons; Mainstream; and Animal Issues. MacKay’s fine art has graced the pages of many popular magazines such as City; Defenders; Bird Watchers Digest; Ontario Naturalist; Seasons; Mainstream; National Audubon; and journals such as The Living Bird and Ontario Birds and The Journal of Raptor Research. He was named the year’s artist for 2013 by Environment for the Americas’ International Migratory Bird Day, and the 2013 artist of the year by Bird Studies Canada. He is the Canadian representative for Born Free, USA.


Barry MacKay’s response to the New York Draft Management Plan for Mute Swans:

  • [The mute swan] is not native but neither is the Ring-necked Pheasant, Brown Trout or, in the Great Lakes, Coho and other salmon species, all of which the DEC is happy to have in spite of the ecological damage that the Salmonids create by directly competing with or eliminating native species; in fact New York taxpayers subsidize these fisheries. While governments claim to abide by the concept of “sustainable use”, they don’t practice it, and these Salmonids (salmon) are constantly replenished (as are other native and nonnative species) through mechanistic, anthropogenic means. Pheasants may be as well, and would also displace native wildlife species.
  • Furthermore, the evidence for the Trumpeter Swan being a nesting species in eastern North America is virtually non-existent…in fact it is non-existent, based on the most questionable interpretation of early records of “white birds” (which could be, depending on where the records occur, and probably were, Snow Geese, White Pelicans or egrets or, on the coast, Northern Gannets, but there is absolutely no empirical proof that they were Trumpeter Swans, and yet we are supposed to silently accept the introduction of Trumpeters into the Great Lakes States and Provinces although these birds are as large as the Mute Swan, also “displace” native species and degrade water quality just as much as do Mute Swans (or an equal biomass of any other waterfowl species…in fact diving ducks, loons, grebes etc. spend more time on the water than do swans). 
  • There is nothing the Mute Swan does…good, bad or indifferent…that is not done by the Trumpeter Swan, plus the latter is noisy, thus more likely to cause human-wildlife conflict. The unstated hope of DEC is that the Trumpeter Swan will become migratory and huntable. In historic times populations of Trumpeter Swans migrated from their breeding range in northwestern and perhaps central northern North America (we really don’t know for sure the limit of their breeding range) to the southern east US coast. Unfortunately Trumpeter Swans derived from the eastern breed and release programs have proved to be non-migratory, or at least as non-migratory as the Mutes (which can migrate to some degree but historically are not migratory in the sense that Trumpeter and Tundra Swans are). So really the fact is that one large swan that “displaces native wildlife species, degrades water quality, and is hazardous to aviation” is being replaced by another that does the exact same things (and if anything is even more aggressive, plus, as I say, noisy).
  • The question of native-ness is moot given that within our lifetime many Eurasian bird species have colonized North America without any direct human assistance, with many waterfowl species (even including closely related Whooper Swan…see: www.ravenidiot.com/docs/whoop_ynp_04.pdf for a discussion) and so there is no inherent reason why, in time, the Mute Swan might not also have colonized North America on its own (or re-colonized since Mute Swan progenitors were apparently found in North America, along with horses, elephants and camels, prior to the Pleistocene extinctions). It can be argued that virtually all fauna now found in NYS is non- native since at the maximum extent of the last ice age virtually all of the state was deeply covered with virtually uninhabitable ice (for map see http://www.iceagenow.com/Ice-Age_Maps.htm) and so there has been a dynamic recovery of biodiversity with formerly non-native species moving into the state that continues to this day, accelerated by climate change.
  • Most of the vegetation now found in areas inhabited by Mute Swans is itself non-native. Even if the Trumpeter was here historically, the habitat it would have encountered is long gone, along with several keystone species that went with it, such as the Passenger Pigeon, the eastern race of Elk, the eastern puma, the heath hen, wolf etc., but mostly including the somewhat contiguous forest cover. We have, effectively Europeanized New York State to the degree that it is, ecologically speaking, far more similar to the Eurasian nesting habitat of the Mute Swan than it is to the known and documented North American nesting habitat of the Trumpeter Swan.
  • Wildlife management agencies, Ducks Unlimited and the hunting industry depend on public ignorance. A question that Mute Swan detractors will not answer: What is it about Mallards, Northern Pintails, cattails, or any other species of fauna and flora found in North America that is so vulnerable to Mute Swans in North America, while the exact same species do just fine in undisputed Mute Swan habitat in Eurasia? Even where there are different species – say a Redshank in Eurasia vs. a Greater Yellowlegs in North America, or a Smew in Eurasia vs a Hooded Merganser in NYS, that makes the North American form so damned vulnerable? The ecosystems are converging, as I said, and so why would a Gadwall be vulnerable to Mute Swans in North America, and not in Europe?
  • The question is pivotal: The government agencies involved have the power to do as they please…they don’t have to answer the question, and the news media and legislators give them far too much leeway.
  • It’s true that Mute Swans create excrement in the water…everything that lives in or on or even near the water does…every muskrat, every otter, every pumpkinseed sunfish, every smallmouth bass, every loon, every kingfisher. The real question is the volume of excrement as a function of contributing biomass. Consider Chesapeake Bay. There we do, indeed, have a bird excrement problem. One species that does not weigh as much as any swan, but also which is in the region year round, is contributing a huge percentage of the avian excrement in the bay even when swans are largely absent…there are 568 million of these birds, and while they are on land, so not all of their excrement may reach the bay, they also outnumber all the waterfowl in the bay many times over. I speak, of course, of chickens (for example, see: http://www.bayactionplan.com/2011/03/big-poultry-clean-up/).
  • The argument is that the Mutes are “displacing” native waterfowl, so if the Mutes are removed (and suddenly all Trumpeters change their ways and somehow find a way not to displace native waterfowl…although how within the realm of physical reality they could do that I’ll leave to others explain) so if we remove the Mutes won’t the native waterfowl thereby not be replaced, and recover? So if, in a NYS pond where there used to be three pair of Mallards, the rest chased by the Mutes…you now have six pairs…won’t that mean a similar amount of excrement?
  • Mutes actually, and in contrast to what is implied if not said outright, don’t tend to chase ducks. They chase geese…Canada Geese, in fact, thus reducing the numbers of a species also being culled because there are “too many”. Might that not be something of a “good” think to these “managers”?
  • Now let’s look at submerged aquatic vegetation (SAV). While sitting on the water and up-tipping (the usual way of feeding… Mute Swans can dive but rarely do) a swan can reach further down to a deeper bottom than can other species, such as Canvasbacks, a type of duck noted for eating SAVs, and one that is a favourite of duck hunters. And they do so year round (Canvasbacks migrate north). So the reach is not really an issue, because the ducks dive regularly and can thus feed even deeper…much deeper…than can the swans, but they do migrate, thus giving the SAV a respite that the swans do not. But that is true of all swans including the Trumpeter Swans (and the native Tundra…it also does all these things but is highly migratory, nesting generally above the treeline in the far north…hence its name, “Tundra” Swan). I understand that the hope is that introduced Trumpeters will somehow become migratory) there are even efforts made to teach them to follow ultra-light aircraft!) but the reality is they tend not to migrate.
  • I would point out the vastly greater threats to SAV such as dredging, various toxic contaminations, agricultural run-off and siltation, climate change and so on, and I would point out that the Mute Swan is what animals always are…a convenient scapegoat whose death can replace the need to make real decision to address real problems. This cabal of waterfowl managers, industry and NGOs really fear that the Mute Swan is in the way of the Trumpeter.
  • I suspect that records will show that the Mute Swan, by virtue of being relatively non-migratory and not flying all that much, is less a hazard to aircraft than the species it “displaces”. It’s really hard to look at any of this empirically because the actual numbers are just so low as to defy a species-based statistical analysis. But even birds as small as the Common Starling have brought down aircraft, so what are we to do? Unless we kill off all flying birds the size of a starling or bigger (think of it…chickadees, emus, penguins and wrens would be safe, but all crows, Blue Jays, Great Blue Herons and Wood Ducks…and hundreds of other species, would have to be exterminated) we cannot make the skies totally safe from birds.
  • The natural progression of a wetland is toward dry land in a process called “succession”. You’ve probably seen the stages of it…first shallow open water, with SAVs, then emergent vegetation (roots below water, tops above) which as it decays and as it holds back silt, slowly fills in to eventually create dry land which is then colonized through more successional stages by shrubs, grasses, forbes and so on. Now then, anything that will slow this process tends to preserve wetlands longer, so the fact that, for example, our native Muskrat will create paths through emergent vegetation (cattails) assists ducks and other species. Swans do this. Some of that vegetation (purple loosestrife, and the Common Reed, or Phragmites) are of concern as it is non-native, but if you ask Mute detractors what the role of the Mute Swan is in mitigating loss of wetland due to these species, if any, since Mutes naturally occur where they do, and you receive blank stares.]


Unseemly Alliances; “Partners” Against Mute Swans

Federal and state wildlife regulatory agencies are partnered with the industries they regulate. The Association of Fish and Wildlife Agencies commingles regulators, trade associations, and manufacturers: Remington Arms, Inc.; Browning Arms, Inc.; Alliant Powder; Olin Corporation; Hodgedon Powder Com.; Blount, Inc.; Marlin Firearms Company; H&R 1871 Inc.; Sturm, Ruger & Co.; O.F. Mossberg & Sons, Inc.; SigArms Corporation; Taurus International Firearms; Weatherby, Inc.; Smith & Wesson; ATK Ammunition Systems; the Archery Trade Association; the Audubon Society (national, affiliates, or independent) and the Nature Conservancy. Seventy-nine percent of state wildlife managers are hunters.

Through AFWA’s “Teaming with Wildlife” (TWW) manufacturers and regulators are partnered with the Audubon Society (national and most state chapters or independents). These few interests slice up the pie, scratch each other’s backs, and benefit from the status quo. The trade-offs are generally at the expense of hunted animals, and, in this case, the splendid Mute. Conservation is a business; all manner of killing is now swept under its rubric.

The TWW National Steering Committee, dominated by shooting trade associations and interests, controls each state’s Wildlife Action Plan (WAP), or wildlife and land policies. State-level TWW affiliates generally include state Audubon societies and a host of TWW satellite organizations, grant brokers, and management consultants. State Audubon Societies may be affiliated with the national organization (chapters) or independent entities.

Perspective; Problems Caused by Commercial Hunting


The case against swans is speculative. By any objective barometer, the quality of the brief does not justify the casual annihilation of Mute Swans in New York.

What is proved: Scores of federal studies conducted on wildlife refuges identify hunting as a primary threat to waterfowl and other birds. Indirect effects are dispersement to poor feeding grounds, depletion of energy reserves for migration (in some cases leading to slow starvation), and disruption of breeding patterns and of family bonds.

The meager case against the Mute Swan does not remotely approach the aforementioned impacts. Yet the hunters’ bureau and its Audubon partners support shooting, and indict the Mute Swan for incalculably less “disruption.”


The indirect impacts of shooting are pernicious and long-term. National Wildlife Refuge System managers rate hunter-caused mortality and disruption the primary cause of “disturbance” to refuge wildlife. As noted by the U.S.

Fish and Wildlife Service:


Direct effects of hunting on waterfowl are death, crippling and disturbance. Bélanger and Bédard (1995) conclude that disturbance caused by waterfowl hunting can: 
  1. Modify the distribution and use of various habitats by birds (Owens 1977; White-Robinson 1982, Madsen 1985);
  2. Affect their activity budget and reduce their foraging time and consequently their ability to store fat reserves necessary both for migration and breeding (Raveling 1979; Thomas 1983); and
  3. Disrupt pair and family bonds and contribute to increased hunting mortality (Bartelt 1987).
Knight and Cole (1995) concluded that hunting alters behavior, population structure, and distribution patterns of wildlife. Hunting can also affect the diversity and number of birds using a site (Madsen 1995).

The U.S. Fish and Wildlife Service literature review, “Managing Visitor Use and Disturbance of Waterbirds,” lists hunters, boats, pedestrians, researchers, anglers, aircraft, and general recreational activities (listed in decreasing order of citations) as “important disturbance sources based on Dahlgren and Korschgen’s 1992 review of 211 waterfowl/human interaction publications (Dahlgren and Korschgen 1992 summarized by Morton 1995, Table 1).”


Northeastern managers report “lowered productivity, aberrant behavior, reduced use of preferred habitat, reduced use of refuge lands, and mortality to be consequences of human disturbance on their refuges (Purdy et al. 1987).”

Purdy et al. (1987) and Pomerantz (1988) categorized destruction and disruption of refuge wildlife and habitat as a direct result of hunting and other human uses: 
  • Direct mortality: immediate, on-site death of an animal;
  • Indirect mortality: eventual, premature death of an animal caused by an event or agent that predisposed the animal to death;
  • Lowered productivity: reduced fecundity rate, nesting success, or reduced survival rate of young before dispersal from nest or birth site;
  • Reduced use of refuge: wildlife not using the refuge as frequently or in the manner they normally would in the absence of visitor activity;
  • Reduced use of preferred habitat on the refuge: wildlife use is relegated to less suitable habitat on the refuge due to visitor activity; and
  • Aberrant behavior/stress: wildlife demonstrating unusual behavior or signs of stress that are likely to result in reduced reproductive or survival rates.
Citations for the most frequent sources of human disturbances of waterfowl in 211 journal articles (Morton 1995 adapted from Dahlgren and Korschgen 1992) rank hunting first, yet the activity is now a “priority public use” on refuge lands:

1) Hunting 71
2) Boating 66
3) Human activity (pedestrians) 58
4) Research/investigator 55
5) Fishing 55
6) Aircraft 47
7) Recreation: general & aquatic 43
8) Development 24
9) Noise 22
10) Roads/traffic 21

The federal literature review holds that “[I]nappropriately managed visitor use can lead to degraded habitat conditions or reduced wildlife use of refuges, as demonstrated by various studies cited in this document.”

National wildlife refuges in the Northeast report that twenty species, including shorebirds, waterfowl, Great Blue Herons, deer, Eastern Bluebirds, and Loggerhead Turtles were all negatively impacted by hunting and other human use of refuges. Managers characterized the impacts to be of “great importance 58.5% of the time, of moderate importance 22.1%, and of minor importance only 19.5%” Exploring on foot, driving on beaches, hunting and driving on roads, feeding and petting wildlife and other recreation were disruptive.

Schummer and Eddleman (2001) report that recreational disturbances (primarily hunting) of waterbirds at Tishomingo National Wildlife Refuge, Oklahoma, accounted for 87 percent of all disturbance while natural natural predation accounted for only ten percent.

Hunting and other human activities cause “two times greater” disruption than do natural predators. At Sacramento National Wildlife Refuge, Wolder (1993) found that “disturbances by humans caused both longer duration of alert and flight behavior in northern pintails than compared to disturbances caused by raptors or other animals. Bélanger and Bédard (1995) found that human related disturbances of greater snow geese were more frequent than natural or unidentified disturbances in both spring (72% vs. 28%) and fall (81% vs. 19%).”

With unknown but apparent frequency, hunters shoot into crows’ nests: 

“Hunters who shoot out nests of crows and black-billed magpies in May to reduce predation of these birds on waterfowl nests have an effect opposite that intended, for flocks of non-breeding crows entering the empty territories.”

According to the U.S. Fish and Wildlife Service literature review:

“The immediate response by wildlife to recreational activity is behavioral changes or death. The long-term effects on individuals are altered behavior, vigor, productivity, or death. The long-term effects on populations are altered abundance, distribution, or demographics; and the long-term effects on the communities are altered species composition and interactions. Burger (1995) describes the nesting and foraging patterns of Atlantic coastal waterbirds (herons and egrets, gulls, terns, and shorebirds) and human recreational activities, including fishing and clamming, waterfowl hunting, boating, swimming, sunbathing, picnicking, jogging and walking, photography, and bird-watching. Considerable temporal and spatial overlap of waterbird use and recreational activities existed (Burger 1995).”

Also:

Human disturbance (one cause alone or many types acting synergistically) may reduce the overall carrying capacity of a given staging area for waterfowl and other waterbirds (Pfister et al. 1992). Disturbances may affect an individual’s energy balance (Fredrickson and Drobney 1979), and in the long-term may affect an individual’s reproduction or survival (Knight and Cole 1995). However, long-term effects of human disturbance are difficult and expensive to study.

Acknowledging the gravity of the situation, the U.S. Fish and Wildlife Service proposed tinkering about the edges and opening more refuges to gunning.

Physiological Response to Hunting

Human predation can cause distinct physiological fight or flight or passive response in other animals present in the area, setting in motion a cascade effect: 

“Gabrielsen and Smith (1995) characterized the “active defense response” or “fight or flight response” by birds and mammals as a physiological response that includes increased heart rate and respiration, increased respiration depth, increased blood flow to skeletal muscle, brain, and heart, increased oxygen consumption, increased body temperature, elevation of blood sugar, increased metabolism, and reduced blood flow to the skin and digestive organs. Lowered body reserves have negative effects on the individuals concerned. When combined with other factors, such as a stressful winter, the animals could die or fail to reproduce. In such cases, populations would decline. The passive defense response involves profound physiological adjustments. Some of the major physiological adjustments for animals exhibiting the response include inhibition of activity, decreased blood flow to skeletal muscle, reduced blood flow to digestive system, reduced heart and respiratory rate, and a reduction of body temperature.”

Anderson (1995) held that “while all impacts on animals cannot be documented, it is clear that loss of body reserves has negative effects on the individuals concerned. When combined with other factors, such as a stressful winter, the animals could die or fail to reproduce. In such cases, populations would decline.”

Federal researchers acknowledge short-term negative impacts; address damaging long-term effects of curtailed feeding and reproduction, and acknowledge that much needs to be learned:

“Some instances are obvious and easy to observe, such as when shooting occurs on a hunt day and birds immediately stop feeding and disperse. In other cases vigilant observation and study may be required, such as interruption of a particular seasonal songbird species while feeding along a well-used trail that is open year-round.”

Displacement; Reduced Feeding

In response to open-water scull-boat hunting in California, brant left the bay and flew to the ocean where food was scarce. Other birds flee to feed on private lands and agricultural fields:

Thompson (1973) reported that waterfowl use was inversely related to human hunting, fishing, and boating; Thornburg (1973) described the local movements of migrating diving ducks as a morning flight at dawn from highly disturbed (hunter, fishing, and boating activity) sections of the refuge. During this time, 90 percent of waterfowl were located on 28 percent of the study area in areas with lower abundance of invertebrates, or food.

Disturbance limits access to food:

“Kahl 1991 suggested that reduced forage access may decrease survival of canvasbacks by causing birds to remain on a staging site longer and forage under suboptimal conditions, or by causing birds to migrate in shorter flights with more frequent stops (Korschgen et al. 1988, Serie and Sharp 1989). Kahl concluded that the frequency of disturbance (boating associated with hunting and fishing) and limited access to food resources documented in his study in Wisconsin suggested that human disturbance is an important management concern. ”

This displacement is directly related to reducing the birds’ vital intake of food.

Hunting Depletes Survivor Energy Reserves

The cumulative, taxing effect of displacement, subsistence feeding, and heightened, frenetic activity -- reduced intake, increased expenditure - caused by hunting is less immediately apparent, but no less real, than outright killing.

When hunting routinely forces migrating birds to forsake high quality feeding areas on refuges, an unknown
percentage cannot survive the winter and simply die. Others are too disabled to breed:

“Henry (1980) concluded that denying brants an undisturbed feeding place during the day could result in a loss of energy and lowered body weight when the birds need to prepare for northward migration and breeding. Hunting activity may increase movements and reduce time for foraging, thereby increasing energy use (Fredrickson and Drobney 1979). Disturbance due to hunting has reportedly reduced time spent in feeding and/or resting activities for several species of wintering or migrating waterfowl (Cronan 1957: lesser scaup; Paulus 1984a: gadwall; Thompson 1973, Thornburg 1973, Korschgen et al. 1985: canvasback; Morton et al. 1989a, Morton et al. 1989b: Black Duck; Bélanger and Bédard 1995).”

For example, a Mallard would need “three days of foraging to replenish fat reserves following an eight hour flight if caloric intake were high.” The researchers note:

“However, if caloric intake was less (only 390 kcal/day), as provided among poor quality habitat types, then the mallard would need eight days to replenish the same reserves. With additional flight time from disturbance, foraging time is correspondingly decreased and prolongs the time necessary to meet nutritional needs. This becomes increasingly important as weather conditions get colder, requiring greater food intake to maintain body condition and weight” (Bias et al. 1997 after Fredrickson and Reid 1988).”

At Chincoteague National Wildlife Refuge, Morton et al. (1989a) found that wintering Black Ducks experienced reduced energy intake while doubling energy expenditure by increasing the time spent in locomotion in response to disturbance. Black Ducks consumed 10.4 times more energy in flight than at rest, and 1.8 times more energy in alert behavior or swimming than at rest (Wooley and Owen 1978 as cited by Morton 1995). Morton et al. (1989a) suggested that human disturbance of wintering Black Ducks impaired their physiological condition, thereby reducing winter survival and/or nutrient reserves carried to the breeding grounds.

In Louisiana, Paulus (1984a) suggested that increased foraging time by Gadwalls was insufficient to counterbalance disturbance factors (primarily hunting), reduced forage quality, and adverse weather conditions. Paulus reported that time spent feeding increased from 44 percent in October to 77 percent in April and noted that Gadwalls spent significantly more time feeding during the night than during the day. Peak feeding activity during day and night usually occurred when daily temperatures were lowest and costs of thermoregulation were greatest.

Fishing results in reduced waterfowl breeding in some areas (Keith 1961, Barngrover 1974, Bouffard 1982).
Anderson (1995) stated that “during the waterfowl breeding season, anglers contributed to a serious decline in breeding waterfowl.”

Researchers in Germany recorded a 90 percent decrease in waterfowl breeding over ten years. The investigators found that a single fisherman “can prevent ducks from establishing territories or selecting nest sites when the area of open water is less than one hectare. Disturbance was less of a problem on larger bodies of water. Intensive angling reduced the number of waterfowl nests by 80 percent, and the remaining nests were found only in areas inaccessible to anglers” (Reichholf 1976).

The biologists observed that “breeding success is also much lower in areas with anglers because of clutch losses to crows (Corvus sp.) and black-billed magpies (Pica pica); the same is true for boating. Also the motor boat's bow wave tips over exposed nests.”

At Seney National Wildlife Refuge in Michigan, managers reported low waterfowl use of refuge wetland areas where fishing was allowed. When fishing was discontinued, “a marked increase in number of broods and adults was observed (Beard 1953).”

Entanglement in fishing line and trammel nets results in waterfowl fatalities (Thompson 1969) and “degradation of wildlife habitat (Liddle and Scorgie 1980).

Viewing and Hiking

Even seemingly innocuous, non-violent activities such as bird-watching (and competitive birding contests), hiking, and photography were impactful. Quick movement, location, noise, distance from an animal, the method of movement, predictability of movement, the number of people, the time of year, “can negatively impact wildlife by altering wildlife behavior, reproduction, distribution, and habitat (Purdy et al. 1987, Knight and Cole 1995)”:

“Nature viewing by its very definition has great potential to negatively affect wildlife. Avid wildlife viewers intentionally seek out rare or spectacular species. Some types of wildlife viewers have a reputation for striving for the most viewing opportunities in the least amount of time (e.g., bird listing). Because these activities may occur during sensitive times of the year (e.g., nesting), and because they often involve close approaches to wildlife for purposes of identification or photography, the potential for negative effects is large.”

More than mere hypocrisy, the litany of disruptions caused by shooting demonstrates the extent to which the New York DEC and Audubon brief against Mute Swans is out of bounds. The proposed draft is a political document that represents the worst of U.S. conservation arrangements and unseemly partnerships. The Mute Swan Management Plan should be shelved.

Sincerely,
Susan Russell
Wildlife Policy Director
Animal Protection League of New Jersey
League of Humane Voters of New Jersey


DeLong, A. K. 2002. Managing visitor use and disturbance of waterbirds — a literature review of impacts and mitigation measures — prepared for Stillwater National Wildlife Refuge. Appendix L (114 pp.) in Stillwater National Wildlife Refuge Complex final environmental impact statement for the comprehensive conservation plan and boundary revision (Vol. II). Dept. of the Interior, U.S. Fish and Wildlife Service, Region 1, Portland, OR.

Purdy, K. G., G. R. Goff, D. J. Decker, G. A. Pomerantz, and N. A. Connelly. 1987. A guide to managing human activity on National Wildlife Refuges. Human Dimensions Research Unit, Department of Natural Resources, Cornell University, Ithaca, New York/U.S. Department of Interior, Fish and Wildlife Service, Office of Information Transfer, 1025 Pennock Place, Suite 212, Fort Collins, Colo. 80524. 57 pp.

Reichholf, J. 1976. The influence of recreation activities on waterfowl. Pages 364-369 in M. Smart, ed. Proceedings of the international conference on conservation of wetlands and waterfowl, Heiligenhafen, Federal Republic of Germany, 2-6 December, 1974. International Waterfowl Research Bureau, Slimbridge (Glos), England.

No comments:

Post a Comment