Ecology and behavior Yellow-bellied sapsucker

holes in dying white birch, jacques-cartier national park


feeding

the yellow-bellied sapsucker forages itself, although joins small groups in winter, , mixes flocks of insectivores in winter.

arthropods, tree sap, fruits, , nuts compose majority of yellow-bellied sapsucker s diet. takes bast , cambium trees. berries eaten, , in northern hemisphere spring, buds eaten. arthropod prey in form of lepidoptera, odonata, or both young , adults of beetles , ants. during nesting season, insects comprise half diet of adults. during late northern hemisphere summer , throughout same hemisphere s autumn, sap primary food of choice. cambium taken throughout year, although eaten during northern hemisphere winter , spring. fruit eaten during october february.

the chicks fed both sexes. primary food insects coated in tree sap before eaten chick. size of these insects varies age of chicks, younger chicks being fed smaller insects. chicks beg food through vocalizations can heard 100 metres (330 ft) away or more, stimulating adults catch more food. these vocalizations done hungriest chick, other joining in when parent @ nest. because of this, hungriest chick gets fed first. when chick leaves nest, relies on both insects parents , sap holes drill.

in breeding season, sapsucker prefers take sap trees betula papyrifera, acer rubrum, amelanchier, , populus grandidentata. other trees of genera populus, betula, , acer used, in addition deciduous trees of genera salix, carya, alnus , coniferous trees of genera pinus, picea, , abies. in northern hemisphere winter , spring, feeds on conifers, while in autumn, feeding on rough-barked trees common.

before feeding consistently on tree, sapsucker lays down exploratory bands near live branch. these bands laid down in horizontal rows. when finds tree photosynthesizing, lays down more holes feed, 0.5 centimetres (0.20 in) above primary bands. these form columns. each hole started oval elongated horizontally, drilled through bark , phloem layers outside of xylem. drilled further, sapsucker enlarging vertically, making yield more sap, few days. top holes in each column provides phloem sap, , sapsucker utilizes bast edges of holes drilled. in winter, when holes drilled on conifers, bast important food.

reproduction

yellow-bellied sapsuckers nest in large cavity excavated in live deciduous tree, choosing 1 has rotten heartwood; suitable tree may reused. prefers populus tremuloides trees have conks of fomes fomentarius var. populinus. other trees in genus populus , in genus betula popular choices. study in northern canada found yellow-bellied sapsucker nested in trees diameter @ breast height (dbh) ranging anywhere 22 79 centimetres (8.7 31.1 in), average dbh of 35 centimetres (14 in) nestling trees, compared average dbh in area of 41 centimetres (16 in). study in northeastern united states, however, concluded sapsucker has search image trees ideal attributes; 1 of these attributes having dbh of 20 25 centimetres (7.9 9.8 in). study concluded deviance search image can caused rarity of trees fulfill such criteria.

this bird monogamous, , nests in pairs, both sexes working make nest. excavation of cavity done male, excavation being done continuously 15 30 minutes @ time. excavation takes 15 28 days, although further hollowing out done both sexes after chicks hatch. cavity anywhere 2 20 metres (6.6 65.6 ft) above ground, although found between heights of 3 , 14 metres (9.8 , 45.9 ft). sapsucker territorial, territories having radius ranging 46 137 metres (150 450 ft) away nest. territories in less wooded areas larger in areas heavily wooded.

the male arrives on nesting grounds 1 week before female. sapsucker arrives in northern hemisphere spring, before heavy snowfall has stopped. actual breeding season april july.

this bird lays clutch of 4 7 eggs, clutches being larger birds in northern part of range. eggs white , spotless, measuring around 24 17 millimetres (0.94 0.67 in). both sexes incubate eggs during 10 13 day incubation period, male doing on night. sapsuckers restless quiet during time, , eggs left uncovered 16% of time during incubation period. weather not effect incubation, although on particularly hot days, parents incubate eggs less time. after 25 29 days, young leave nest first time, , become independent after 2 weeks.