An online resource based on the award-winning nature guide

Brood

Chestnut-sided Warbler Sitting On Eggs

Different species of birds have different numbers of broods (sets of eggs/young).  Eastern Bluebirds can have up to four broods per breeding season, American Robins up to three and Eastern Phoebes often two.  Chestnut-sided Warblers typically only raise one family in a summer. If weather or predation destroys their first attempt, however, they will re-nest, which is just what the pictured female Chestnut-sided Warbler is doing.

By August, a majority of birds have raised their young, but there are birds that nest late in the season, some naturally (American Goldfinches) and some, such as this Chestnut-sided Warbler, by necessity.  Where birds nest, geographically, affects the number of broods they have. Birds nesting at higher latitudes tend to produce fewer broods per year.  Because it gets colder earlier than further south, there is less time to raise their young.  In warmer regions, birds often raise two or even three broods per year. (Thanks to Dean and Susan Greenberg for photo op.)

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Black Bears Seeking Protein

9-2 hornet nest torn by bear 083Although insects and animal matter make up less than 10% of the annual black bear diet, they are a crucial part of it. Black bears get most of their animal protein from ant brood, hornet larvae, tent caterpillars, march fly larvae, grubs (especially June beetle grubs), and snow fleas. Among the most preferred sources are bee and hornet larvae. Berries and other fruit don’t have a great amount of protein, but they do have some (blackberries = 2 grams of protein per cup). If the summer berry crops fail, insect brood is especially important, especially at this time of year, when bears are seeking protein, fats and carbohydrates, putting on as much as 30 pounds per week to sustain themselves through the coming months of hibernation.

When tearing apart a beehive, yellow jacket nest or bald-faced hornet nest (see photo), bears do get stung, particularly on their ears and faces (their fur is fairly impenetrable). Apparently the reward is worth the aggravation. After filling themselves with brood (and in some cases, honey) black bears shake vigorously in order to rid themselves of any insects that are caught in their fur.(Thanks to Alfred Balch for photo op.)

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate”
button.


Black-throated Blue Warblers Incubating Second Brood

8-1-14 -female black-throated blue warbler on nest 054Male and female Black-throated Blue Warblers differ strikingly in appearance, so much so that the two sexes were considered separate species by early naturalists, including John J. Audubon. While the male is a brilliant blue, the female is dull gray which makes her practically invisible when she’s on a nest.

Black-throated Blue Warblers have anywhere from one to three broods in a summer, the first usually in June, a second, if there is one, in July and rarely a third in late July or early August. The nest is usually within three feet of the ground, and is built out of thin strips of birch bark and bits of rotten wood bound together by cobwebs and saliva. Fibers, rootlets, needles and mammalian hair line the nest. Female Black-throated Blue Warblers are known for sitting tightly on a nest until a potential threat is very close, at which point they drop to the ground, and, similar to Killdeer, engage in a distraction display, feigning injury to their wing.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.