Habitat
Henslow’s Sparrows breed in wet meadows, weedy pastures, and lowland prairie. As native habitats disappeared they also moved into cultivated hayfields. Historically, they bred in Atlantic coastal marshes. They now use reclaimed surfaces in the Ohio River basin and seem disposed to use large fields of tall, dense grass away from trees or other woody vegetation. Their winter habitat is similar, though they seem more tolerant of trees. They are frequently found in fire-maintained pine savannahs.
Back to topFood
Eats insects in summer, mostly grasshoppers, beetles, and caterpillars. In winter, forages on the ground for seeds including wiregrass, sedges, ragweed, smartweed, and some berries.
Back to topNesting
Nest Placement
Nests on or very near the ground, at the base of thick clumps of grass among thick litter.
Nest Description
The female builds the nest by loosely weaving dried grasses together, placing the cup loosely on grass clumps or leaf litter.
Nesting Facts
Clutch Size: | 3-4 eggs |
Number of Broods: | 2-3 broods |
Incubation Period: | 10-12 days |
Egg Description: | Glossy white, with speckles and blotches. |
Condition at Hatching: | Eyes closed, covered with brownish-gray down. |
Behavior
The Henslow’s Sparrow is extremely secretive in all seasons, spending most of its time on or near the ground foraging for insects and seeds. They are loosely colonial on the nesting territories, with nesting pairs keeping relatively close to one another but still maintaining nonoverlapping territories separated by an unoccupied and undefended buffer. Territorial males sing either from an exposed perch or hidden on the ground. Henslow’s Sparrow behavior on the wintering grounds is difficult to determine, as the species is extremely secretive and often silent.
Back to topConservation
Henslow’s Sparrow populations were stable or slightly declining between 1966 and 2015, according to the North American Breeding Bird Survey. However, Partners in Flight suggests a steeper decline in the species, and places it on their Yellow Watch List for species with declining populations. They estimate a global breeding population of 410,000 and rate the species a 14 out of 20 on the Continental Concern Score. Loss of breeding habitat is most likely the biggest threat to Henslow’s Sparrow populations. Fire suppression, conversion of pasture to agriculture, wetland drainage, and urbanization are all cited as reasons for this species’ declines. It is listed as an endangered species in Canada. Additionally, seven U.S. states have listed Henslow’s Sparrow as endangered, five have listed it as threatened, and four have listed it as a species of Special Concern. Grassland conservation efforts, specifically the federal Conservation Reserve Program, have been responsible for the reversal of some long-term declines among local populations of this species.
Back to topCredits
Herkert, James R., Peter D. Vickery and Donald E. Kroodsma. (2002). Henslow's Sparrow (Ammodramus henslowii), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.
Lutmerding, J. A. and A. S. Love. Longevity records of North American birds. Version 2015.2. Patuxent Wildlife Research Center, Bird Banding Laboratory 2015.
Partners in Flight (2017). Avian Conservation Assessment Database. 2017.
Sauer, J. R., D. K. Niven, J. E. Hines, D. J. Ziolkowski Jr., K. L. Pardieck, J. E. Fallon, and W. A. Link (2017). The North American Breeding Bird Survey, Results and Analysis 1966–2015. Version 2.07.2017. USGS Patuxent Wildlife Research Center, Laurel, MD, USA.
Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.