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Posts tagged “American Robin

White Baneberry Fruits Mature

8-15-13 white baneberry fruit 056All parts of the White Baneberry plant (as well as Red Baneberry) are highly toxic. The fruit, called “doll’s eyes” for obvious reasons, is the most poisonous part, known to cause respiratory paralysis and cardiac arrest in humans. It does not have this effect on all mammals, however. White-tailed deer are known to browse on baneberry, and small rodents such as mice, squirrels and voles feed on the fruit. Geometrid moth larvae (“inchworms”) burrow into the fruits and their seeds while they (the fruits) are still green. A wide variety of birds, including American Robins and Yellow-bellied Sapsuckers, eat the fruit, helping disperse the plants when they excrete the brown, wedge-shaped seeds (insert). Ruffed Grouse also eat the fruits, but the seeds are destroyed in the digestive process. Oddly enough, Native Americans used the juice of Red Baneberry to gargle with as well as to poison their arrows.

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Birds & Ticks

7-18-13  song sparrow with tick 252Several recent studies demonstrate that wild birds are actively transporting ticks and their associated diseases during migration. In addition, a number of bird species are able to contract Borrelia burgdorferi (the bacterial causal agent of Lyme Disease infection) and transmit it to uninfected ticks that parasitize the birds for a blood meal. Since ground-feeding species such as Northern Cardinals, Gray Catbirds, Song Sparrows (pictured) and American Robins spend a significant amount of time foraging for food at the optimal height for ticks, they are excellent hosts and have all demonstrated the ability to infect larval ticks with Borrelia burgdorferi upon their first blood meal. (Look carefully at the Song Sparrow’s neck and you will find a tick.)


Foraging Technique of American Robins

4-17-13 A. robin2 IMG_8800In the fall and winter, fruit makes up about 90% of an American robin’s diet. In the spring, only 10% of a robin’s diet consists of fruit; invertebrates make up the remaining 90%. (Summer is a fairly even mixture of both.) At this time of year, earthworms are a popular food item with robins. Watching a robin foraging for a worm can make you wonder whether the robin is using its ears or its eyes to locate the worm. It turns out that most worms are seen, not heard, by robins. Because the sound of worms burrowing in the soil is of low intensity, they usually cannot be heard by robins because of background noise. Using sight, not sound, the robin first aims one eye toward a spot on the ground in front of it, and after holding this position for a few seconds, rotates its head and draws a bead with its other eye on the same spot– an earthworm in its burrow. The robin then quickly thrusts its bill into the burrow in an attempt to get its next meal.


Staghorn Sumac to the Rescue

3-5-13 A. robin eating sumac IMG_4893They may not be sweet, plump and juicy, but the fruits of staghorn sumac play a crucial role in the lives of many birds that overwinter in New England. True, they’re not a preferred food for these birds, but because they persist through the winter, these fuzzy fruits are an important source of food in late winter and early spring, when very little else is available. Ruffed grouse and wild turkeys rely on sumac fruit as a source of food throughout the winter, and bluebirds, robins, cardinals, mockingbirds and starlings are frequent visitors to staghorn sumac shrubs this time of year.


Overwintering American Robins

While some American robins usually overwinter in northern New England, we have a larger number of them this winter than usual.  A lack of snow cover and an excellent crop of fruits and berries are contributing to this phenomenon. You often see them in flocks of a hundred or more, especially on south facing fields, and where there are fruit trees. Migration is a hazardous undertaking for birds, and in general they go only as far south as they need to in order to survive.  If there is an ample supply of food, and a lack of snow, robins are more likely to remain in northern New England during the winter, or stop here on their way south from Canada.