The bald eagle has been making a remarkable comeback across North America since the use of DDT was banned in 1972. The pesticide was found to be passed up the food chain in increasing concentrations. The high levels found in bald eagles (being at the top of the food chain) disrupted the absorption of calcium and the females laid eggs with thin shells. This caused a serious decline in the rate of successful hatches. While their numbers have climbed, there are still less than 30 pairs that nest in this province.
A mature bald eagle is easy to identify. The pure white head and tail feathers (which occur during the fourth or fifth year) contrast starkly with the jet black wings and body. With a wingspan of up to 2.8 m (7.5 ft), the eagle is our largest bird of prey. Younger birds up to three and four years old lack the distinctive white head and tail, having a dark, mottled appearance. From a distance, bald eagles are easy to spot with their long, broad wings held almost horizontal as they glide.
Almost all eagle nests in this province are in large, old eastern white pines, generally near water and with good food sources. White pines can offer perfect places for eagles to build their large nests. The pines are often above the surrounding forest canopy and can be seen for long distances. Pines have large, flat branches and the soft wood leaves the top prone to breakage. This can leave a solid base to build upon. The nest gets added to each year and will be reused unless the pair is disturbed or the tree itself is damaged. The pine’s soft wood also means that tree tops containing the heavy nests can snap off in a bad storm, so it is important to think of having a succession of large trees that might be suitable for nests.
Though it has enormous size and grace, the bald eagle is more of an eating machine than a highly efficient predator. It lacks the maneuverability of a falcon and the silence of an owl and so must often make do with picking up leftovers. These include mostly fish (including dead ones), wounded ducks and road kill. In recent years eagles have become more plentiful and one reason is that they feed upon the waste from animal processing plants and farms that compost dead animals.
Over the past twenty years, bald eagle populations have been doing well in this province, though that is no reason to take their presence for granted. Many threats continue to create problems for these magnificent birds. Some of these include:
Lack of buffer zones – While it is illegal to kill an eagle, its habitat is another matter. Buffer zones are important for the protection of bald eagles, since birds can abandon nests if disturbed. The eggs are laid in April and take about five weeks to hatch. After that, it is another 10 weeks or more before the young eaglets can fly. Until then, they are relatively defenceless. If they are frightened from their nest, they will most likely die from the fall or starve on the ground. It only makes sense to have a relatively small buffer that prevents any cutting near the nest, and a wider buffer that prevents serious disturbance during the nesting season.
While there are no hard and fast rules as to what exact sizes these buffer zones should be, other jurisdictions have set up regulations and guidelines. Regulations in Ontario call for a 100 m (330 ft) “Primary Zone” buffer around the nest, restricting “all land use except actions necessary to protect or improve the nest site.” A “Secondary Zone” buffer extends for an additional 100 m from the nest, prohibiting “activities that result in significant changes in the landscape, such as clear-cutting, land clearing, road construction, pipeline development, hydro rights-of-way or major construction. Activities such as thinning tree stands or maintenance of existing improvements are permitted in the Secondary Zone, but not during the most critical and moderately critical periods. A “Tertiary Zone” extends 400 m (1/4 mile) but may extend up to 800 m (1/2 mile) if topography and vegetation permit a direct line of sight from the nest to potential activities at that distance. The configuration of this zone can be variable and it is the least restrictive area. On Prince Edward Island, we need to set some restrictions to protect nesting bald eagles and then carry out more research and monitoring to see if these buffers are doing the job.
Snares – Over the past few years, trappers have been increasing the number of snares set out for coyotes. Until 2003, these traps were often set out in the open, and it was quite common to catch scavengers such as bald eagles and even barred owls in these traps. The carcasses used for bait were placed in the woods and the access paths covered by snares. Eagles didn’t have sufficient room to land beside the bait. Instead they landed in adjacent open areas and walked into the snares. The heavy snare wire prevented the eagles from escaping. Some died in the snares, others were found and released, though there are no assurances that the releases were successful. In an effort to solve the problem, regulations now prohibit the setting of snares within 50 meters of bait. The exception is when placing bait in open fields. The regulation further requires that bait placed in the woods be covered so it is not visible to eagles, owls, ravens and other birds from the air. The problem is not supposed to occur if bait is placed in open fields. In those instances, eagles land beside the bait and do not encounter the snares. It will take time and serious monitoring to see if these regulations solve the problem. Are eagles still being caught in snares when the new rules are followed? Are all trappers following the regulations? These are the questions that need to be asked and hopefully strong monitoring and enforcement will give us the answers.
Illegal hunting – in November of 2003, a dead bald eagle was found in a tree near Mount Stewart, with its talons cut off. Despite the efforts of the provincial conservation officers and rewards offered by several groups, no charges have been laid. Unfortunately, this is not the first time an eagle has been shot in the province. The fine for a first offence in the province is only $400, so it is time to take action and create a more serious deterrent. What is the life of an eagle worth?
Pesticides – Fish kills have become an unfortunate, though relatively commonplace occurrence most summers on Prince Edward Island. The increase in potato acreage has led to pesticides getting into streams from neighbouring fields, resulting in poisoned fish floating upon our rivers and ponds. While the public focus has been on the dead fish, a sick bald eagle was found after a nearby river was poisoned. The eagle was later euthanized to end its suffering. Although no conclusive cause of the illness was ever found, the eagle had all the characteristics of being poisoned. Bald eagles eat a lot of dead fish – they are part of nature’s cleanup crew. Pesticides can also be transferred from a poisoned fish to a scavenging eagle. It does not seem far fetched to think that at the very least fish kills pose a threat to all who might see dead fish floating on a river as a fast food restaurant.
Absence of suitable nesting trees – Almost everyone in the province seems to be aware that we are cutting wood at unsustainable rates. Despite this recognition, there is continuing pressure on our forest resource. While the focus has primarily been on white spruce, other species, including large old white pine, continue to be targeted. Given the age of the trees that bald eagles use for nests, we may at some time in the future face a shortage of suitable nesting and roosting trees of the right age and location. There is very little protected forest land in the province. Some excellent examples of protection do exist, including a large area of white pine protected by the province in Brudenell, some of the Island Nature Trust’s Natural Areas, and the Macphail Homestead in Orwell (which combines protection with restoration). Many other areas need this type of protection and both landowners and the provincial government may need to look at growing nesting trees for 200 years in the future.
Shoreline development – Increased development along the shores of both the ocean and larger rivers is occuring across the province. Too often trees are cut down to improve “viewscapes”, which can create a loss of prime nesting habitat. The increased activities in these areas also leads to more human disturbances around nesting sites.
Some positive steps have been taken recently. The provincial government has been active in carrying out much needed research and educational programs on bald eagles, including excellent publications and an ambitious banding program. Government has also restricted the use of lead shot for hunting waterfowl (which helps protect both the waterfowl and eagles from lead poisoning). The Island Nature Trust has an Adopt an Eagle Program for elementary and junior high school students. For a donation of $100 the class, group or individual receives a 20-page booklet on the eagles of Prince Edward Island and a certificate with the adopter’s name on it plus the band number and nest location of their eagle. If it is a class, they will also be treated to a slide show on eagles and may also get a chance to see the young eagles they have adopted get banded.
One thing that landowners can do, given that most of our bald eagles nest on privately owned land, is to protect their own forest habitat, paying special attention to white pines. If you have them, let at least some of them get old and tall, and if you don’t have them, plant some. It may take a hundred years or more to get to usable size, but this is a case of people having to take the initiative for ensuring the long term survival of these birds. As well, the public can bring its concerns to local politicians about how to safeguard eagles and other raptors. This could be through establishing buffer zone legislation, eliminating pesticides in our waterways, or creating stronger penalties for infractions. We can all help in ensuring that these beautiful birds continue to be successful in our province.