The best advice that can be given to anyone who desires to attract hummingbirds and orioles to their backyard is to keep their feeders filled with a fresh supply of nectar and free of dirt, mildew and ants.
As the temperatures rise, the chance that the nectar will sour increases. This is usually only a problem in the beginning of the season, until such time as the traffic to your feeders increases. Many people find themselves replenishing the nectar supply once a day, so that it is always fresh and inviting. But, if you have numerous feeders, you may find that one or more of your feeders last for days at a time.
The best rule of thumb is to change the nectar every 3-5 days. If the weather is hot, or your feeder is in direct sunlight, then it should be changed every 2 days. These flighty little dinner guests depend upon you for their sustenance. If they cannot find adequate flowers by which to nourish themselves, they depend heavily upon their human friends to supply them the nectar that maintains their health. Hummingbirds and Orioles will not normally feed from feeders that have fermented or have gone sour, but if they do, they can become very sick. The colorful and delightful display that these backyard visitors entertain us with is our reward for taking care of their nutritional needs.
