Cattle egrets are considered outliers in the heron
family (Ardeidae) because of their preference for drier land. They are best
known for their association with cows and other livestock, for which they are
named, and their bright golden plumes during breeding season.
Standing on average about 20 inches (50 cm) tall and
with a wingspan of about 36 inches (92 cm), cattle egrets are shorter and more
compact that most other heron species (Cornell Lab of Ornithology). Juveniles
are white with dark bills and legs; upon maturing, the bills turn yellow and
the legs a yellowish-grey. During the breeding season, adults sport bright
orange plumes on their heads, breasts, and backs, which distinguishes them from
other species and makes them quite easy to identify; the legs and bill may also
turn a bright red (Ivory, 2000). There is little sexual dimorphism, besides the
males being slightly larger and having slightly longer plumes than the females.
Herons as a family are characterized as wetland birds,
but the cattle egret seems to prefer drier upland areas or agricultural lands
for foraging. However, they breed and roost in established wetland colonies
with other species of herons and egrets.
The species originated in Africa, and scientists
speculate that they arrived in the Caribbean around the turn of the 20th
century. The first few individuals are believed to have flown from Africa to
South America early in the year when winds were favorable (Massa, Doyle, and
Callico Fortunato, 2014), and spread northward through the region from there
(Arendt, 1988). They are now widely distributed not only in the Caribbean, but
throughout the Americas (Cornell Lab of Ornithology).
The cattle egret keeps strange company (for a bird),
but this association makes sense when you consider their diet and resourceful
nature. Their diet is varied, consisting of insects and other invertebrates,
fish, frogs, and sometimes even smaller species of birds. They are much more
efficient when foraging alongside grazing livestock, which stir up their prey
from the vegetation and make them more accessible (Heatwole, 1965; Thompson,
Lanyon, and Thompson, 1982). They can also be seen standing on the backs of
their companions, picking off ticks and other pests, and thus, their
relationship is considered symbiotic.
Cattle egrets also forage next to farming equipment,
like tractors, and are suspected brood parasites, sometimes laying their eggs
in the nests of other herons (Greenspan, 2016). These adaptable, opportunistic
birds make the best of every situation.
The cattle egret is listed as “Least
Concern” by the IUCN, with an estimated population between 4 and 10
million individuals worldwide (BirdLife International). The species is still
expanding its range across the globe, but locally it faces two major threats.
Removal of mangroves and other wetlands reduces available breeding habitat, and
agricultural pesticides can bioaccumulate in their prey, contaminating their
food source. Education and pesticide control are needed to ensure these
striking, resourceful birds are around for future generations to admire.