Frugivory and habitat use by fruit-eating birds in a fragmented landscape of southeast Brazil

To investigate the movement of seeds transported by fruit-eating birds in an agricultural, fragmented landscape of the Atlantic forest of southeast Brazil, I asked which bird species are the main seed dispersers in such environment, and how they use the available habitats (small forest fragments, forest thickets, live fences, isolated trees, and active pastures) where they are most likely to drop the seeds they swallow the relative importance of fruit-eating birds as seed vectors was evaluated based on the number of fruit species eaten, the number of visits, and visitation rate to fruiting plants. Habitat use was accessed by recording the habitats where birds were seen or heard during walks conducted throughout the study area. Sixteen plant species were observed during 308.3 plant-hours. Forty-one bird species were observed eating fruits in a total of 830 visits to fruiting plants. Sayaca Tanagers (Thraupis sayaca) and Pale-breasted Thrushes (Turdus leucomelas) ate the greatest number of fruit species, were the most frequent plant visitors in terms of number and rate of visits, and had a broad range of habitat use. These two species and the Rusty-margined Guan (Penelope superciliaris), which is able to swallow large fruits with large seeds that smaller bird species cannot cat, likely have a great contribution to the movement of seeds throughout this highly degraded landscape.

Bird diversity and abundance in forest fragments and Eucalyptus plantations around an Atlantic forest reserve, Brazil

Little of Brazil's remaining Atlantic forest is protected, so it is important to assess how well the region's wildlife can persist in areas/habitats outside reserves. We studied bird diversity and abundance during 546 point counts in the Sooretama/Linhares reserve, 200 point counts in 31 forest fragments (10-150 h), and 50 point counts in < 30-year-old Eucalyptus plantations, within 7 km of the reserve. Only eight bird species were recorded in Eucalyptus, and this impoverishment, as compared to some Eucalyptus plantations elsewhere in Brazil may be a result of intensive clearance of understory vegetation. Species diversity in forest fragments was significantly lower than in the reserve. Twelve, mostly non-forest or edge species, were significantly commoner in the fragments, but nineteen species were frequent in the reserve but rare or absent in forest fragments. These included two Pyrrhura parakeets, a Brotogeris parakeet, a trogon Trogon, a jacamar Galbula, woodpeckers Piculus and Campephilus, Myrmotherula antwrens, and Hemithraupus and Tachyphonus tanagers. Bird species richness at points in forest fragments did not decline with fragment size, distance from the reserve, or forest quality. However, forest in fragments was more heavily degraded than forest within the reserve and poor forest quality may be the cause of declines in some species. Whilst protection of forest within reserves is a priority, management of forest fragments may aid conservation of some threatened species.

Birds at Eucalyptus and other flowers in Southern Brazil: A review

In southern Brazil, I recorded 14 species of hummingbirds, one woodpecker, three Psittacidae, four Tyrannidae, one mockingbird, and 31 tanagers and relatives at eucalyptus flowers. Others have registered 3 different hummingbirds, another parrotlet, four more tyrannids, a peppershrike, a thrush, and 5 tanagers and related birds, for a total of 69 species. However, commercial plantations rarely flower, so use is local or undependable. Understory Phaethorninae are not recorded at eucalyptus, rarely at other tall and hence multiflowered trees. Bromelias and other flowers are noted in various studies, which add 89 species of flower feeders, including 14 Psittacidae, 17 Trochilidae, and 37 tanagers and relatives. Isolated low flowers and epiphytes are mostly visited by hummingbirds (some by Coereba), but some tall trees (Chorisia) also. As two times as many tanager species visit flowers as hummingbirds, researchers will have to get up early and patiently study treetop and nonpatchy habitats. However, tree plantations can attract artificially, like feeders. Bunch-flowering extrafloral nectar (Mabea, Combretum) is preferred by wandering mixed-flock treetop or edge tanagers and relatives, which often crawl over bunched flowers like parrots or woodpeckers (or marsupials and other mammals) rather than hover at separate flowers like nonflocking Trochilidae or peck from nearby like Nectariniidae and Coereba. Clamberers and petal-pullers, even nectar robbers, can cause evolution of umbels and other bunched flowers, for the bird, mammal or insect receives pollen from nearby flowers. Psittacidae, saltators and others mostly eat flowers, but can pollinate if they touch nearby flowers. Multiflowered trees can also attract hawks, causing waves of tanagers, parrots and others that move on to pollinate trees via fear and nectarivory. Certain groups, notably thrushes and tyrannids, seem to use nectar little, the latter often catching insects.