Beavers construct their mud and stick homes or "lodges" out in ponds and marshes. If water levels fluctuate or they hear water flowing, they build dams to contain the water. Their diet mainly consists of the bark, twigs and shoots of trees such as hawthorne, crabapple, and birch here. although they sometimes eat blackberry and cattail in summer. To get their main construction materials and foods (trees), they cut them down with their sharp front teeth. Although you are unlikely to see beavers during the daytime, you can spot a dam next to the inner trail in the northeast corner , and all throughout the Sanctuary there are little rafts of cut trees, twigs and branches that are their feeding stations.

At the Sanctuary, we co-exist more or less peacefully with the beavers for most of the year, just wiring some of our favourite trees from being cut down and eaten. Somehow, though, by November, the relationship deteriorates, and some of the culverts critical to drainage during the rainy months end up looking like war zones. Trees start vanishing or are found lying across paths each morning, piles of twigs appear along waterways, and heaps of mud and sticks seem to grow by most culverts. These are not lodges, but are the "discarded weapons of war" or the twigs and mud put there by the beavers and raked away and put off to the side by us.

Beavers and staff end up using various strategies to win the war over water. We take rakes and shovels to clear the pipes and controls for low tide drainage. The beavers hear the sound of water flowing into pipes, and get to work the moment we are gone. They have the advantage, as they work at night when we are not watching. In the fall, they are also storing their winter food supplies, so they naturally have a lot of building materials. By morning, all of our efforts towards drainage have been stymied by barriers of mud, grass,and sticks built by energetic beavers overnight. We remove all of that so the beavers will have something to do the next night.

It is a good thing that winter cold temperatures put a temporary end to these disputes. When water freezes, and there is no rain, there is no need for drainage, and no sound of running water. Both Team Human and Team Beaver then can relax and not fight for a while.

Follow-up ideas: During your walk around, see if you can figure out where the beavers are most active, based on the clues above.

Although our Gift Shop sells small bags of bird seed mainly for ducks, you can also ask for the sunflower seeds for chickadees. Keep still with seeds in your hand, and hold your hand out when you are in the tree-lined trails and a tiny black and white bird might come to visit. When chickadees take a seed, they usually land nearby and peck off the outer shell of the sunflower seed before eating it, but sometimes they store the seed in the bark of a tree for later, and come back to you for more right away. They also eat small insects, spiders, berries, and seeds of the big trees. During cold weather, a chickadee might have to eat food that equals between 150 and 250 sunflower seeds a day to survive. Food is energy to keep warm.

Watch also for other small birds in the area, what they are eating, and whether they even seem interested in seed treats. You should not expect many bird species to be interested in feeding from your hand, as that is an unnatural behavior for wildlife. Most animals like to find their own food. We sell seeds for chickadees because they are mainly seed-eaters and are willing to come close to people. There are many other birds out there that do not get close to people or have non-seed diets, so we like to keep the habitat healthy, with waterways and diverse plants to provide an ongoing natural source of foods for all of those types of birds. Many wrens and woodpeckers, for example, are insectivores (eat insects), and American Robins and Cedar Waxwings are mainly fructivores (eat berries and other fruits). Hawks, eagles and owls are carnivores and want to catch other living animals such as birds or rodents.

Follow-up ideas: Set up a bird feeder at home; plant a bird-friendly habitat garden.

Try not to make too much noise or disturb birds so that they need to use up valuable energy reserves. It is an excellent time to walk quietly through the woods and to think about the concept of "cover" or the parts of the habitat that shelter birds from the rain, snow, cold and wind. Along the Douglas Firs of East Dyke, for example, the combination of dense branches thick with needles, and an understory of dense shrubs provides many discrete spaces for small birds to shelter, and dark quiet areas for owls to sleep during the day or "roost". Great Horned Owls, the Northern Saw-whet Owl (featured above), and Barred Owls all like to roost along this path during the day, and hunt all over the Sanctuary at night. Please do not try to wake them up or get too close to them, and do not touch or alter any of the roost sites.

At this time of year, exploring after a brief snowfall can also be very interesting, as the furry animals of the Sanctuary join with the birds in leaving tracks in the snow all along our trails. River Otter, Coyote, Beaver, Mink, Muskrat and Raccoon all seem to leave tracks after a snowfall, as well as the Eastern Gray Squirrel.

Follow-up Ideas: Work with your child's teacher to arrange for a program at OWL (Orphaned Wildlife Rehabilitation in Delta) to learn more about birds of prey, how they rescue and help birds, and how you can help; Investigate tracks in the snow in your own neighbourhood.

Every living thing needs water. Water is everywhere at this time of year, falling from the sky and moving past us in the form of ocean waves, river channels and ponds. When International Wetland Day happens every February 2nd, Vancouver people never seem very keen about the value of all of this water. However, Canada is one of 120 countries that signed on to the "Ramsar Convention" committing to preserving the globally signifiance wetlands within their own countries, and the Sanctuary lies within one of these "Ramsar sites".

Wetlands are the buffering habitat to keep water in the system. A wetland is a place where the "land is wet", literally, but where plants and animals are adapted to life in water and help keep water slowly moving through our ecosystem. At the Sanctuary, the main wetlands are marshes.The view from the tower overlooks the estuary marshes that are critical to the coastal fish and wildlife that live along BC's Coast. Along our pond edges, freshwater marsh plants such as Cattail provide endless nesting material, insects and nest cover for many small birds and waterfowl.

Follow-up ideas: During your walk, watch the beginnings of nesting season for the Marsh Wrens as they start to assemble their small ball-like nests out of the Cattail.; At the tower, look out over the Fraser Estuary; download our colouring sheet about International Wetland Day.

Birds have diverse ways to keep their nests safe. Some, like the Bald Eagles, place their large obvious stick nests high up in trees and out of reach of most predators. Crows and hawks make a smaller version of these stick nests but place them a little lower in the trees where the spring growth of leaves will disguise them.

Songbirds such as the Song Sparrow, Spotted Towhee, Cedar Waxwings, and Robins build even lower to the ground, but deep in the bushes and generally wait until the spring cover grows dense.

Many of the ducks and the Canada Geese are ground nesters and seek places near the water where there is some dead grassy material to pile up and form into a shallow mound to nest on and to blend in with the surrounding ground cover.

Speciallized nesters include the Barn Swallow, with its carefully crafted mud nest, the Marsh Wren and its closed in ball of Cattail leaves and seed head material, and the cavity nesting birds that use either holes in trees or the nest boxes we have installed.

Every year, our visitors harm nesting birds in their enthusiasm to see nests. A person too close to a nest draws attention to it, attracts the interest of predators, and may cause the parent bird to at least temporarily abandon care of the eggs. Please stay at least 2 m away from nests.

Any kind of bird feeding activity close to a nest also brings too much attention to it. The end result is that many nests get destroyed by other birds, predators such as racoons, mink, crows or gulls. Think of a nest as a maternity ward. No partying!

Visitors should all know that it is illegal to disturb nesting birds, and that they will be asked to leave if they stay too close to nests, cause parent birds to leave eggs exposed, interfere with the nest by adding bird seed, or try to touch eggs. Many nests have been abandonned or predated because people have not paid attention to the basic need of nesting birds to be left alone and unnoticed. Let the birds keep these nests as their little secret.

There are many other birds also nesting, so remember to keep on the trails to avoid trampling plants, nests and even young birds.

Birds have one or the other of two different styles of rearing their young safely to full-grown flying adult-sized birds. Geese, ducks, cranes, and most shorebirds raise "precocial" young that are all downy and active as soon as they hatch and are able to follow their parents and be feeding themselves within a few days of hatching. It is critical for these young to remain with at least one parent bird though, for as much as a month or two. Initially, they are downy but not waterproof, and the parent bird finds a safe place in the plant cover to keep them warm and safe overnight from predators by tucking them underneath her body. In their second month, they start to grow body feathers and are about half-grown, so this need lessens.

"Altricial" birds such as herons, eagles, woodpeckers, and songbirds such as chickadees have young that hatch blind and helpless and remain in the nest for many weeks being fed by the parent birds. As with the precocial birds, altricial chicks grow quickly, but in the nest, and start to get their body feathers and eventually their flight feathers.

The length of time from hatching to flying is quite variable between species. Larger birds such as duck, geese, herons, cranes, eagles, and owls all take about three months to grow to a fully-feathered flying adult size. Small songbirds, though, can get to that stage in just three weeks..

Within the warm stew of nutrients and small plants and animals in the water, these organisms quickly grow to a mature size in an elongated larval form, then undergo a transformation into our more familiar flying form of these animals. Looking for signs of these insects can be very interesting. Sometimes you can see larvae swimming in the shallows if the water is clear and hasn't been recently stirred up by ducks.

These insects have a hard exoskeleton, and in order to change shape or even size, they regularly "shed" this outer skin, and during metamorphosis, changes occur under the skin during pupation, and the new form emerges from inside the old skin.

Mosquito larve are not very noticable in the water, but just before they transform ino adult flying mosquitoes, they take the form of a comma shaped active pupa that does somersaults in the water. Eventually the pupa rests at the water surface, the outer skin splits to allow the emergence of an adult hungry mosquito.

Dragonfly and damselfly larvae or "nymphs" climb up onto the vegetation, just out of the water, and over a few days, they shed their old skin and fly off in their new form, leaving behind an exact but empty larvae-shaped exoskeleton still clinging to the reed. It is always very interesting in May and June to see all of the recently-transformed damselflies resting on the plants along the trails. When they first emerge from their old larvae-shaped skin, their wings are all foldened up, and it takes a day or so of circulation and resting with their wings straight fr them to stiffen into the transparent functionning wings.

Wildflowers that are most showy in July are the Peavine, Goldenrod, Purple Loosestrife, Tufted Vetch and clouds of Mayweed or False Camomile and Thistles. Thistles (Russian and Bull Thistles) are interesting and American Goldfinches love their dandelion-like seeds when the flowers have passed.

At this time of year, the Salmonberries and various wild cherries are finished, but Salal, Mountain Ash, Cascara, Twinberry, and Pacific Crabapple are all ripe, and birds such as Cedar Waxwings and Robins are particularly fond of these fruits. Himalayan Blackberries are ripe and abundant, but we ask people not to pick them as the hedges are managed to provide cover as well as food, and when we leave unpicked juicy berries on the canes, the dried up berry becomes a cluster of small seeds of value to many birds over the winter.

Parents should make sure children understand the idea of leaving these resources for the birds. Also make sure they do not even sample berries that are unfamiliar, such as Deadly Nightshade, Cascara, Twinberry, Honeysuckle, and a few other fruits that can cause medical issues one way or another. Marsh plants such as Cattail and Bulrush should not be picked either, as these are important building materials for next spring for birds such as the Marsh Wren.

What Grows Here, Stays Here.

One of the reasons we have posted the outer dyke paths as a Quiet Zone and No Feeding Zones is to encourage visitors to quietly watch the shorebirds and observe their natural and speciallized mud feeding.

Some of the more common larger shorebirds are the Greater and Lesser Yellowlegs (named for their bright yellow legs), and the Long-billed and Short-billed Dowitchers which are heavy-bodied and probe with their long bills straight down into the mud as they walk, giving them the nickname of sewing-machine birds. Watching all of these shorebirds roaming across the mud, it is hard to see what most of them are eating, as the "food" is often discovered, captured and eaten while their bills are still deep in the mud. Their long tongues extend the length of their bills, and they can taste the small clams, amphipods and worms buried there. Yellowlegs often move to swishing their bills through the shallow water to catch small fish such as the Three-spined Stickleback.

Birdwatchers often spend hours scrolling through big flocks of Yellowlegs and Dowitchers looking for other less common species such as Stilt Sandpipers, Ruffs, and Solitary Sandpipers.

The robin-sized birds running rapidly across the mud with large horizontal strips across their chests are Killdeer, named after their "kill-dee, kill-dee" call. In August, we also see small shorebirds floating and spinning on the surface of the water, picking off flies. These are Phalaropes.

The smaller shorebirds, often nicknamed "peeps", give short peeping calls in flight and can be either solitary or feeding in flocks of hundreds of birds. To identify them, observers need to note bill colour and shape, leg colour, markings on the tails and wings and things like eyestripes or eye-rings in addition to the overall body markings. Western, Least, Semi-palmated, Dunlin, Pectoral, Baird's, and Sharp-tailed Sandpipers are all seen in our ponds during migration. In addition to probing in the mud, many of the small sandpipers appear to be eating tiny items right at the surface of the mud. Scientists have concluded that the almost mucous layer of marine proteins, bacteria and slime that holds intertidal mud together at the surface is an important part of their diet during migration.

Think of how you might wear a warm sweater against your body, but a rain jacket over that in the Vancouver area, as it rains a lot, and wet sweaters are not very warm. Ducks have much the same strategy. Their downy fluffy feathers are thick against their skin and trap lots of warm air. The outer waterproof feathers shed the rain, keeping their "sweater" of down dry. To keep these outer featers waterproof, the birds preen and spread oily waxes from a special gland at the base of their tail called a Uropygial gland. When you hear about oil spills and birds in distress, it is because the heavy industrial oils have clogged their outer feathers, and their inner feathers are wet and cold as a result.

Prime feathers also help attract mates. As many ducks do not have strong pair bonds all year, they spend the late fall and winter doing all sorts of courtship displays to attract mates for the spring nesting season. No one likes a scruffy date!

For example, the Pacific Flyway is the general route taken from the Yukon Territories, Alaska and BC nesting areas, southwards through BC river valleys and funnelling down to the Pacific Coast to wintering areas down in the west coast States, Mexico, or even further south. Birds of the Central Flyway migrate between Canada's arctic down through the Prairie Provinces and into the southern USA to meet up with birds in the Missippi Flyway and Atlantic Flyway.

Major flyways like this are used by all the birds, not just waterfowl, as they are the routes most practical to follow when migrating for thousands of miles. The large scale routes usually have lots of suitable habitats to support many species of birds during their migration. Conservation of large tracts of suitable habitat by establishing parks or other wildlife areas along these major migration routes goes a long way to preserving species over the long term.