Common Loon Migration Update: February 25, 1999 Today's Report Includes: Loons on Their Wintering Grounds Salt of the Earth Challenge Question # 1 Start Watching for Loons How to Respond to Today's Challenge Question Loons on Their Wintering Grounds Right now many of the loons wintering in the ocean have lost the ability to fly. Are they sick? Nope. Injured? Nope. In big trouble? Nope! They're simply molting, growing a whole new set of flight feathers before their migration back to their breeding grounds. Wing feathers are so light and buoyant that they float. For loons to dive and chase fish underwater without popping back up like a cork, their wings are as small as possible. Eagles and hawk often fly about-hunting or migrating- while missing two or three wing feathers. If a loon were to try to fly while missing three wing feathers, the surface area of its wing would be too small to hold up its body! As it is, to get up and stay up, loons must beat their wings fast and steady, and virtually never soar or glide even for a moment! Loon in breeding plumage Photo: Woody Haage But feathers get worn out, frayed and weakened, and so loons grow new ones every year. These new feathers will carry them hundreds, or even thousands, of miles to their breeding grounds in a month or two, and then carry them back to the ocean again next fall. It takes a lot of energy and body resources to grow feathers. Loons grow a lot of large, stiff feathers all at once. They can become severely stressed if they are already weakened from some disease, for example. Or, if they have toxic chemicals stored in their body fat, when the fat is used for feather growth, these toxins can suddenly flood their system. Sometimes they even may die. A few times, there has been a large loon die-off in the ocean. When this tragic event happens, it's usually February, right when loons are molting and most vulnerable. Salt of the Earth Photo: Woody Haage A loon hatches and grows up in freshwater. Then it flies to the ocean where its diet changes suddenly to saltwater fish. When it rains, it can drink rainwater dribbling along its beak. While it's raining, it may also drink from the water's surface before the lighter freshwater gets completely mixed in with the salty ocean. If days pass without rain, the loon has no choice but to drink saltwater. If humans drink even just half a glass of saltwater, they throw up. This is actually to protect our bodies, because if our blood and tissues became too salty, we would die. The amount of salt in loon tissue is comparable to ours, even when they live in the ocean. Why don't they throw up when they must suddenly drink salt water? Which leads us to this week's Challenge Question # 1 How do loons adapt to salt water? Start Watching for Loons Report the first Loon you see this spring to Journey North! In many places, this is a good time to start watching for loons. First make sure you know what to look for. Swimming cormorants and mergansers look a LOT like loons, especially in poor light. Check out Journey North's Loon ID page, go out to open lakes to look and listen for these swimming birds, and report your sightings to Journey North! Meanwhile, watch for loon migration updates with information from loon biologist Lucy Vlietstra, reporting from Monterey Bay. How to Respond to Today's Challenge Question 1. Address an e-mail message to: jn-challenge-loon@learner.org 2. In the Subject Line of your message write: Challenge Question # 1 3. In the body of your message, answer the question. The Next Loon Migration Update Will be Posted on March 11, 1999 Copyright 1999 Journey North. All Rights Reserved. Please send all questions, comments, and suggestions to our feedback form