Operation Nest Mirror (click here)
Even for birds, things sometimes don’t go as planned. In fact, we’ve found that for Rose-Breasted Grosbeaks, life often doesn’t follow its intended course. None of the Grosbeak nests we’ve found have lasted until the chicks fledged, and many were “popped” (eaten) or abandoned before the eggs even had a chance to hatch. After six failures, but before we resigned ourselves to the apparent curse of the Pheucticus, we did a little research. Friesen, Cadman, and MacKay found that only 46% of the Rose-Breasted Grosbeak nests they kept tabs on made it to completion, i. e. 54% of their nests did not yield any fledglings (1999). Compared to our 0% success rate, 46% was looking pretty good. However, Dungay, Woods, and Nichols reported a success rate of only 32% (2001). Consultation of the Birds of North America account revealed that our Grosbeaks’ low success rate may also be a consequence of the fragmented nature of the available habitat. Despite their preference for fringe habitats, Rose-Breasted Grosbeaks also tend to have a lower nesting success rate in more fragmented habitats....
All About Birds:(click here)
Could be vulnerable to loss of habitat, but current numbers apparently stable.
Two males share the record for the oldest Rose-breasted Grosbeak. Both birds were at least 12 years, 11 months old when recaptured and released during bnding operations. One was banded in 1972 in Vermont and found in the same state in 1984. The other was banded in Maryland in 1976, and recaptured in 1987 in the same state.
Rose-breasted Grosbeaks breed in moist deciduous forests, deciduous-coniferous forests, thickets, and semiopen habitats across the northeastern United States, ranging into southeastern and central Canada. They gravitate toward second-growth woods, suburban areas, parks, gardens, and orchards, as well as shrubby forest edges next to streams, ponds, marshes, roads, or pastures. During migration, grosbeaks stop in a wide variety of habitats including primary and secondary forest, wet and dry forest, shrub thickets, pine woods, shrubby dune ridges, scrub, urban areas, and wetlands. They spend the winter in forests and semiopen habitats in Central and South America, often in middle elevations and highlands (up to about 11,000 feet in Colombia).
Males sing to establish territories and attract females. When a female approaches, the male rebuffs her for a day or two before accepting her as a mate. Once mated, Rose-breasted Grosbeaks appear to be monogamous. A breeding pair will tolerate migrant males in their territory if the intruder is silent. Otherwise, territorial males ward off male intruders by spreading their tails, flicking their wings, raising their crown feathers, and often chasing the intruder away. Males respond strongly to recordings of Rose-breasted Grosbeak songs and Black-headed Grosbeak songs, but they attack mounted specimens of their own species 5 times more often than they attack specimens of the other species. Females drive off other females that approach their mate. Both male and female Rose-breasted Grosbeaks share incubation, brooding, and feeding duties at the nest. Nest predators include Blue Jays and Common Grackles—which breeding grosbeaks will mob noisily and aggressively near the nest—along with red and gray squirrels. Adult grosbeaks are hunted by predators such as Cooper’s Hawks and Sharp-shinned Hawks. During migration and winter Rose-breasted Grosbeaks are found individually, in pairs, or in loose flocks, sometimes with other species.
Rose-breasted Grosbeaks are common forest birds but their populations experienced a slow decline from 1966 to 2015, resulting in a cumulative loss of about 35% during that time, according to the North American Breeding Bird Survey. Partners in Flight estimates a global breeding population of 4.1 million, with 46% spending some part of the year in the U.S., 21% in Mexico, and 54% breeding in Canada. The species rates an 11 out of 20 on the Continental Concern Score. Rose-breasted Grosbeak is not on the 2016 State of North America's Birds' Watch List. These birds nest in saplings, so their numbers could be dropping as forests start to mature over the eastern United States. Because they look and sound pretty, Rose-breasted Grosbeaks are commonly trapped for sale as cage birds in their wintering range, and this has an unknown impact on their population.
