Distribution
The red-whiskered-bulbul is native to India,
Nepal, Bangladesh, Burma, and also ranges from the Indo-Chinese subregion
to Hong Kong and the South China coast (Berger, 1972). It has been introduced
to Malay Peninsula, Singapore, Nicobar Islands, Mauritius, Australia, mainland
US and the Hawaiian Islands (Long, 1981). It is now very common on O'ahu (Hawai'i
Audubon Society, 1993) and just as common as the red-vented bulbul. The first
red-whiskered bulbul was observed in lower Makiki in the fall of 1965 and
later in the Nuuanu and Manoa valleys (Williams, 1983). These birds are said
to have become established due to an accidental release (Williams, 1983).
Lowell Dillingham noted that the Makiki birds were probably released from
an aviary when a koa branch fell and crashed on the roof of the bulbul cages
(Williams, 1983). In addition, there was another accidental release of bulbuls
from an aviary maintained at Diamond Head by John Petrous (Williams, 1983).
The initial observations of bulbuls were in rather scattered regions of the
island, this led to the theory that the birds were introduced in several places
at separate times (as supported by the above examples) (Williams, 1983). Subsequently,
this was supported by the observation that these bulbuls are sedentary and
rarely fly large distances (Williams, 1983). The initial observations were
made by John Kjargaard in 1968: at our home in lower Makiki Heights our first
sighting of a red-eared Bulbul was in the fall of 1965. At that time we saw
a pair flitting in and out of a mock orange hedge. In 1966 we saw a number
of birds, and in the fall of 1967 we counted as many as 24 at one time...We
have seen them mostly during the cooler months of the year (Kjargaard, 1968).
Closely coinciding observations were also made by Mary Roberts, "a cousin
on O'ahu Avenue has also seen them in his garden, and a friend on Coelho Way
reported frequent visits and feeding on the fruits of a date palm last year"
(Kjargaard, 1968). The Audubon Society's O'ahu Christmas count in 1968 noted
that "during the past few months, four red-whiskered Bulbuls (Pycnonotus
jocosus) have been frequent visitors to the McGuires yard high on Pacific
Heights...These are new to the Honolulu count and to Hawai'i. Although undoubtedly
escapees, or descendants of escapees, two seem to be immature, apparently
released successfully this year" (Hawai'i Audubon Society, 1968).
Description
The red-whiskered bulbul averages about 7 inches
in length (Hawai'i Audubon Society, 1993) and weighs about 23 to 42 grams
(Long, 1981). The bulbuls are naked at hatching, the lining of the mouth is
red and changes to yellow at the mid palate (Berger, 1981). Their eyes are
still closed at the age of three days (Berger, 1981). The birds are brownish
above and white below; the head is black with a pointed crest, and there is
a crimson patch behind the eyes from the whiskers (Berger, 1972). The `tail
coverts are red and the ends of the outer tail feathers are white (Berger,
1972). The males are distinctive with yellow underparts, and the females are
non-descript but resemble few other birds (Pratt, 1987). The immature birds
are like the adult but do not have the red ear patch (Hawai'i Audubon Society,
1993).
Food
The red-whiskered bulbul feeds on fruits and
insects. The nestlings are fed soft bodied insects and caterpillars and as
they get older, they eat berries and other fruits (Berger, 1981). The adults
have been seen eating date palm, papaya, mango, autograph tree, loquat, avocado,
octopus tree and mock orange (Berger, 1981). They are also known to eat flower
parts and nectar, ants and seedlings (Long, 1981).
Breeding
The breeding season is variable ranging from January to August and there are
two to three broods per season (Long, 1981). The nest is cup-like made of
fine twigs, rootlets, grass and is often found in trees, thatch walls or roofed
huts (Long, 1981). Ohashi and Ueoka (1977) describes that, "the outer
portion of the nest was constructed with large, coarse material. Leaves, tissue
paper, wax paper and cotton were used to form the base of the nest, while
grass runners and twigs were interwoven to form the sides". Each clutch
has about two to three eggs and are oval in shape. The eggs have a pinkish
background, are heavily freckled and mottled with reddish brown or purple
spots that are concentrated at the larger end of the egg (Berger, 1981). Tthe
incubating adult sat tight and appeared not to be disturbed despite close
observation and nest measuring" (Ohashi and Ueoka, 1977).
Movements
This bulbul is commonly kept as a cage bird
in South East Asia (Long, 1981). It is also seen on forest edges, secondary
growth, woodland areas, parklands, gardens and villages (Long, 1981). They
are gregarious and tend to fly in pairs or in flocks of 20 to 30 during the
winter (Long, 1981). These birds are known to be sedentary more so than the
red-vented bulbul (Long, 1981).
Red-whiskered Bulbul (Pycnonotus
jocosus).
This species is native to Burma, East Pakistan,
Thailand, South China, and the lowlands of eastern
India (Reilly 1968). In 1960, 5-10 red-whiskered bulbuls, originally from
Calcutta, India, escaped from captivity at the Miami Rare Bird Farm and established
themselves in a suburban area in the southern fringes of Miami, Florida (Owre
1973). They first nested in 1961, and by 1969-1970 the population had increased
to 250 (Carleton and Owre 1975). Carlton (1971) studied the species in the
Dade County environment. She estimated that during the first 10 years of the
bird's establishment in Dade County, the annual increment of the total population
was 30-40 percent. Because the red-whiskered bulbul's native habitat and southeastern
Florida have similar climates and because many of southeastern Florida's exotic
plants are also from India, the red-whiskered bulbul easily adapted to its
new environment (Stoll 1977). In Florida, the red-whiskered bulbul eats the
fruits of the Brazilian pepper tree (Schinus terebinthifolius), the fig tree
(Ficus spp.), and jasmine (Jasminum spp.) and the drupes and berries of 24
other small exotic plant species that proliferate in residential areas (Carleton
and Owre 1975). Many people have also purposely attracted these birds by putting
up feeding stations around homes.
Although exotics can become nuisances at any
time, the red-whiskered bulbul has not yet become a threat. Robertson and
Woolfenden (1992) reported that red-whiskered bulbul populations have spread
minimally and are barely surviving. Stoll (1977) believed that the red-whiskered
bulbul may be in competition with the mockingbird (Mimus polyglottos) because
the food habits of the two species are similar. If its populations grow substantially,
the red-whiskered bulbul may pose future problems to fruit growers. The only
real danger that now exists is the bulbul's diet of Brazilian pepper drupes.
The bird may become a major pathway by spreading the seed of the Brazilian
pepper in Florida. As the birds fly to new areas, viable seeds from droppings
germinate. The red-whiskered bulbul may also intensify the spread of this
noxious exotic (Stoll 1977).
Cattle Egret (Bubulcus ibis). Although the cattle egret is not typically classified as an aquatic species, it is a nonindigenous species with high visibility. This species belongs to a taxon that is known to peregrinate or migrate (Owre 1973). Because this species may have migrated to the New World and to Florida on its own, it may not be an exotic species. The cattle egret's pathway of introduction is unknown. However, its sudden appearance, increase in numbers, and range expansion soon after it was first observed are similar to those of other exotic species. W.E. Dilley first discovered the cattle egret in the United States near Clewiston, Hendry County, in summer 1941, and on 5 May 1953, G. Chandler and S.A. Grimes found nesting individuals of this species at King's Bar, Lake Okeechobee (Sprunt 1955). In summer, cattle egrets are now common throughout Florida except in the Keys; during winter, the abundance of these birds considerably declines (Robertson and Wolfenden 1992). Unlike most exotic birds, the cattle egret invaded Florida on its own (Owre 1973).
The cattle egret established itself because it can easily adapt its diet to the habitat. This species is most noted for its adaptability and non-competitiveness (Sprunt 1954). Cattle egrets are most typical on pastures where they follow cattle or plows and prey on flushed insects, including insects that are considered pest species and fill empty niches. Although the cattle egret nests in the same colonies and forages on the same grounds as the native herons (Family Ardeidae), its variable diet precludes serious competition with other heron species (Fogarty and Hetrick 1973). Because of its status as an adaptive, non-competitive species, the cattle egret was deliberately introduced to the Seychelles and to the Hawaiian Islands to control flies (Long 1989). However, the cattle egret preys on the eggs of ground-nesting birds in Africa and America (Cunningham 1965). Although the bird is considered a pest by many environmentalists, it consumes many insects and to our knowledge has not created major environmental problems.
Budgerigar (Melopsittacus undulatus). The budgerigar, commonly known as the budgie, is indigenous to interior Australia. Budgerigars are popular pets throughout the world but are established only in Florida (Forshaw 1973). This species nested in Pinellas County as early as in the 1950's (Robertson and Woolfenden 1992). It nests at Horseshoe Beach, Dixie County; in Hudson, Pasco County, south to Fort Myers, Lee County (Wenner and Hirth 1984); and in Naples, Collier County. Budgerigar may once have been established around Jacksonville, Duval County, but no further sightings have been made in this area (Robertson and Woolfenden 1992). At one time, a population of budgerigars in St. Petersburg was so large, it was a tourist attraction (Owre 1973). Many sightings were reported elsewhere in the peninsula, in the Keys, and in the panhandle of Florida (Robertson and Woolfenden 1992). Populations of budgerigars peaked at many thousands in the later 1970's and declined in the 1980's (Robertson and Woolfenden 1992). Although the population sizes and the number of locations declined, budgerigars may still be seen throughout southern Florida. They inhabit watercourses, sparsely timbered grasslands, dry scrublands, open plains, and residential areas of southern Florida, and Immelman (1968) believed that they are the most prolific Australian parrot of the United States.
