The birds-of-paradise are members of the family Paradisaeidae of the order Passeriformes. The majority of species are found in eastern Indonesia, Papua New Guinea, and eastern Australia. The family has 42 species in 15 genera.[1] The members of this family are perhaps best known for the plumage of the males of the sexually dimorphic
species (the majority), in particular the highly elongated and
elaborate feathers extending from the beak, wings, tail or head. For the
most part they are confined to dense rainforest habitat. The diet of all species is dominated by fruit and to a lesser extent arthropods. The birds-of-paradise have a variety of breeding systems, ranging from monogamy to lek-type polygamy.
A number of species are threatened by hunting and habitat loss.
Taxonomy and systematics
For many years the birds-of-paradise were treated as being closely related to the bowerbirds. Today while both are treated as being part of the Australasian lineage Corvida,
the two are now thought to be only distantly related. The closest
evolutionary relatives of the birds-of-paradise are the crow and jay
family Corvidae, the monarch flycatchers Monarchidae and the Australian mudnesters Struthideidae.[2]
A 2009 study examining the mitochondrial DNA
of all species to examine the relationships within the family and to
its nearest relatives estimated that the family emerged 24 million years
ago, earlier than previous estimates. The study identified five clades within the family, and placed the split between the first clade, which contains the monogamous manucodes and paradise-crow, and all the other birds-of-paradise, to be 10 million years ago. The second clade includes the parotias and the King of Saxony bird-of-paradise. The third clade provisionally contains several genera, including Seleucidis, the Drepanornis sicklebills, Semioptera, Ptiloris and Lophorina, although some of these are questionable. The fourth clade includes the Epimachus sicklebills, Paradigalla and the astrapias. The final clade includes the Cicinnurus and the Paradisaea birds-of-paradise.[3]
The exact limits of the family have been the subject of revision as well. The three species of satinbird (the genera Cnemophilus and Loboparadisea)
were treated as a subfamily of the birds-of-paradise, Cnemophilinae. In
spite of differences in the mouth, foot morphology and nesting habits
they remained in the family until a 2000 study moved them to a separate
family closer to the berrypeckers and longbills (Melanocharitidae).[4] The same study found that the Macgregor's bird-of-paradise was actually a member of the large Australasian honeyeater
family. In addition to these three species, a number of systematically
enigmatic species and genera have been considered potential members of
this family. The two species in the genus Melampitta, also from New Guinea, have been linked with the birds-of-paradise,[5] but their relationships remain uncertain, more recently being linked with the Australian mudnesters.[2] The silktail of Fiji
has been linked with the birds-of-paradise many times since its
discovery, but never formally assigned to the family. Recent molecular
evidence now places the species with the fantails.[6]
Hybrid birds-of-paradise may occur when individuals of different
species, that look similar and have overlapping ranges, confuse each
other for their own species and crossbreed.
When Erwin Stresemann
realised that hybridisation among birds-of-paradise might be an
explanation as to why so many of the described species were so rare, he
examined many controversial specimens and, during the 1920s and 1930s,
published several papers on his hypothesis. Many of the species
described in the late 19th and early 20th centuries are now generally
considered to be hybrids, though some are still subject to dispute;
their status is not likely to be settled definitely without genetic
examination of museum specimens.
Birds-of-paradise are closely related to the corvids. Birds-of-paradise range in size from the king bird-of-paradise at 50 g (1.8 oz) and 15 cm (5.9 in) to the curl-crested manucode at 44 cm (17 in) and 430 g (15 oz). The male black sicklebill,
with its long tail, is the longest species at 110 cm (43 in). In most
species, the tails of the males are larger and longer than the female,
the differences ranging from slight to extreme. The wings are rounded
and in some species structurally modified on the males in order to make
sound. There is considerable variation in the family with regard to bill shape. Bills may be long and decurved, as in the sicklebills and riflebirds, or small and slim like the Astrapias.
As with body size bill size varies between the sexes, although species
where the females have larger bills than the male are more common,
particularly in the insect eating species.[2] Plumage
variation between the sexes is closely related to breeding system. The
manucodes and paradise-crow, which are socially monogamous, are sexually
monomorphic. So are the two species of Paradigalla, which are polygamous. All these species have generally black plumage with varying amounts of green and blue iridescence.[2]
The female plumage of the dimorphic species is typically drab to blend
in with their habitat, unlike the bright attractive colours found on the
males. Younger males of these species have female-like plumage, and
sexual maturity takes a long time, with the full adult plumage not being
obtained for up to seven years. This affords the younger males the
protection from predators of more subdued colours, and also reduces
hostility from adult males.[2]
Habitat and distribution
The centre of bird-of-paradise diversity is the large island of New Guinea; all but two genera are found in New Guinea. The two that are not are the monotypic genera Lycocorax and Semioptera, both of which are endemic to the Maluku Islands, to the west of New Guinea. Of the riflebirds in the genus Ptiloris, two are endemic to the coastal forests of eastern Australia,
one occurs in both Australia and New Guinea, and one is only found in
New Guinea. The only other genus to have a species outside New Guinea is
Phonygammus, one representative of which is found in the extreme north of Queensland.
The remaining species are restricted to New Guinea and some of the
surrounding islands. Many species have highly restricted ranges,
particularly a number of species with restricted habitat types such as
mid-montane forest (like the black sicklebill) or island endemics (like the Wilson's bird-of-paradise).[2]
The majority of birds-of-paradise live in tropical forests, including rainforest, swamps and moss forest,[2] nearly all of them solitary tree dwellers.[7] Several species have been recorded in coastal mangroves.[8] The southernmost species, the paradise riflebird of Australia, lives in sub-tropical and temperate wet forests. As a group the manucodes are the most plastic in their habitat requirements, with in particular the glossy-mantled manucode inhabiting both forest and open savanna woodland.[2]
Mid-montane habitats are the most commonly occupied habitat, with
thirty of the forty species occurring in the 1000–2000 m altitudinal
band.[8]
The diet of the birds-of-paradise is dominated by fruit and
arthropods, although small amounts of nectar and small vertebrates may
also be taken. The ratio of the two food types varies by species, with
fruit predominating in some species, and arthropods dominating the diet
in others. The ratio of the two will affect other aspects of the
behaviour of the species, for example frugivorous species tend to feed
in the forest canopy, whereas insectivores may feed lower down in the
middle storey. Frugivores are more social than the insectivores, which
are more solitary and territorial.[2]
Even the birds-of-paradise that are primarily insect eaters will
still take large amounts of fruit; and the family is overall an
important seed disperser for the forests of New Guinea, as they do not
digest the seeds. Species that feed on fruit will range widely searching
for fruit, and while they may join other fruit eating species at a
fruiting tree they will not associate with them otherwise and will not
stay with other species long. Fruit are eaten while perched and not from
the air, and birds-of-paradise are able to use their feet as tools to
manipulate and hold their food, allowing them to extract certain
capsular fruit. There is some niche differention in fruit choice by
species and any one species will only consume a limited number of fruit
types compared to the large choice available. For example, the trumpet manucode and crinkle-collared manucode will eat mostly figs, whereas the Lawes's parotia focuses mostly on berries and the greater lophorina and raggiana bird-of-paradise take mostly capsular fruit.[2]
Breeding
A male Victoria's riflebird displays and is inspected by a female.
Most species have elaborate mating rituals, with the Paradisaea species using a lek-type mating system. Others, such as the Cicinnurus and Parotia species, have highly ritualised mating dances. Males are polygamous in the sexually dimorphic species, but monogamous in at least some of the monomorphic species. Hybridisation
is frequent in these birds, suggesting the polygamous species of bird
of paradise are very closely related despite being in different genera.
Many hybrids have been described as new species, and doubt remains
regarding whether some forms, such as Rothschild's lobe-billed bird of paradise, are valid.[citation needed]
Birds-of-paradise build their nests from soft materials, such as
leaves, ferns, and vine tendrils, typically placed in a tree fork.[9] The typical number of eggs in each clutch
varies among the species and is not known for every species. For larger
species, it is almost always just one egg, but smaller species may
produce clutches of 2–3. eggs[10] Eggs hatch after 16–22 days, and the young leave the nest at between 16 and 30 days of age.[9]
Societies of New Guinea often use bird-of-paradise plumes in their dress and rituals, and the plumes were popular in Europe in past centuries as adornment for ladies' millinery. Hunting for plumes and habitat destruction have reduced some species to endangered status; habitat destruction due to deforestation is now the predominant threat.[2]
Best known are the members of the genus Paradisaea, including the type species, the greater bird-of-paradise, Paradisaea apoda.
This species was described from specimens brought back to Europe from
trading expeditions in the early sixteenth century. These specimens had
been prepared by native traders by removing their wings and feet so that
they could be used as decorations. This was not known to the explorers,
and in the absence of information many beliefs arose about them. They
were briefly thought to be the mythical phoenix.
The often footless and wingless condition of the skins led to the
belief that the birds never landed but were kept permanently aloft by
their plumes. The first Europeans to encounter their skins were the
voyagers in Ferdinand Magellan's circumnavigation of the Earth. Antonio Pigafetta
wrote that "The people told us that those birds came from the
terrestrial paradise, and they call them bolon diuata, that is to say,
'birds of God"."[11] This is the origin of both the name "bird of paradise" and the specific name apoda – without feet.[12] An alternate account by Maximilianus Transylvanus used the term Mamuco Diata, a variant of Manucodiata, which was used as a synonym for birds-of-paradise up to the 19th century.
Birdwatching
In
recent years the availability of pictures and videos about birds of
paradise in the internet has raised interest of birdwatchers around the
world. A lot of them fly to West Papua to watch various species of birds
of paradise from Wilson's Bird of Paradise (Diphyllodes respublica) and Red Bird of Paradise (Paradisaea rubra) in Raja Ampat to Lesser Birds of Paradise (Paradisaea minor), Magnificent Riflebird (Ptiloris magnificus), King Bird of Paradise (Cicinnurus regius), and Magnificent Bird of Paradise (Diphyllodes magnificus) in Susnguakti forest.
This activity significantly reduces the number of local villagers who are involved in the hunting of paradise birds.
Hunting
Hunting
of birds of paradise has occurred for a long time, possibly since the
beginning of human settlement. It is a peculiarity that among the most
frequently-hunted species, males start mating opportunistically even
before they grow their ornamental plumage. This may be an adaptation
maintaining population levels in the face of hunting pressures, which
have probably been present for hundreds of years.[citation needed]
The naturalist, explorer and author Alfred Russel Wallace spent six years in what was then called The Malay Archipelago
(published 1869), shooting, collecting and describing many specimens of
animals and birds including the great, king, twelve-wired, superb, red
and six-shafted birds of paradise.[13] Hunting to provide plumes for the millinery trade was extensive in the late 19th and early 20th century,[14]
but today the birds enjoy legal protection and hunting is only
permitted at a sustainable level to fulfill the ceremonial needs of the
local tribal population. In the case of Pteridophora plumes, scavenging from old bowerbird bowers is encouraged.
Other examples
The southern hemisphere constellation Apus represents a bird-of-paradise.
The Indonesian Army has a Military Area Command named after "Cenderawasih", the local name for the bird.
The plume from the bird of paradise was used in the Royal crown worn by the King of Nepal, before the establishment of a republic. Now, the crown is housed in Naraynhiti Palace
The white-tailed deer (Odocoileus virginianus), also known as the whitetail or Virginia deer, is a medium-sized deer native to the United States, Canada, Mexico, Central America, Ecuador, and South America as far south as Peru and Bolivia.[2] It has also been introduced to New Zealand, Cuba, Jamaica, Hispaniola, the Bahamas, the Lesser Antilles, and some countries in Europe, such as Finland, the Czech Republic, Romania and Serbia.[3][4] In the Americas, it is the most widely distributed wild ungulate.
In North America, the species is widely distributed east of the Rocky Mountains as well as in most of Mexico, aside from Lower California, and in southwestern Arizona. It is mostly replaced by the black-tailed or mule deer (Odocoileus hemionus) from that point west. However, it is found in mixed deciduousriparian corridors, river valley bottomlands, and lower foothills of the northern Rocky Mountain region from South Dakota west to eastern Washington and eastern Oregon and north to northeastern British Columbia and southern Yukon, including in the Montana Valley and Foothill grasslands.
The conversion of land adjacent to the Canadian Rockies into agriculture use and partial clear-cutting of coniferous trees
(resulting in widespread deciduous vegetation) has been favorable to
the white-tailed deer and has pushed its distribution to as far north as
Yukon. Populations of deer around the Great Lakes
have also expanded their range northwards, due to conversion of land to
agricultural uses favoring more deciduous vegetation, and local caribou and moose populations. The westernmost population of the species, known as the Columbian white-tailed deer, once was widespread in the mixed forests along the Willamette and Cowlitz River valleys of western Oregon and southwestern Washington,
but today its numbers have been considerably reduced, and it is
classified as near-threatened. This population is separated from other
white-tailed deer populations.
Male white-tailed deer (buck or stag)
Taxonomy
Fawn waving its white tail
Some taxonomists have attempted to separate white-tailed deer into a host of subspecies, based largely on morphological differences. Genetic studies,[clarification needed]
however, suggest fewer subspecies within the animal's range, as
compared to the 30 to 40 subspecies that some scientists described in
the last century. The Florida Key deer, O. v. clavium, and the Columbian white-tailed deer, O. v. leucurus, are both listed as endangered under the U.S. Endangered Species Act. In the United States, the Virginia white-tail, O. v. virginianus,
is among the most widespread subspecies. The white-tailed deer species
has tremendous genetic variation and is adaptable to several
environments. Several local deer populations, especially in the southern
states, are likely descended from white-tailed deer transplanted from
various localities east of the Continental Divide.
Some of these deer populations may have been from as far north as the
Great Lakes region to as far west as Texas, yet are also quite at home
in the Appalachian and Piedmont regions of the south. These deer, over time, have intermixed with the local indigenous deer (O. v. virginianus and/or O. v. macrourus) populations.
Central and South America have a complex number of white-tailed deer
subspecies that range from Guatemala to as far south as Peru. This list
of subspecies of deer is more exhaustive than the list of North American
subspecies, and the number of subspecies is also questionable. However,
the white-tailed deer populations in these areas are difficult to
study, due to overhunting in many parts and a lack of protection. Some
areas no longer carry deer, so assessing the genetic difference of these
animals is difficult.
Some subspecies names, ordered alphabetically:[5][6]
Female white-tailed deer (doe)
North America
O. v. acapulcensis – Acapulco white-tailed deer (southern Mexico)
O. v. borealis – northern white-tailed deer (the largest and darkest of the white-tailed deer)
O. v. carminis – Carmen Mountains white-tailed deer (Texas-Mexico border)
O. v. clavium – Key deer or Florida Keys white-tailed deer (the smallest North American subspecies, found in the lower Florida Keys; an example of insular dwarfism)
O. v. chiriquensis – Chiriqui white-tailed deer (Panama)
O. v. couesi – Coues' white-tailed deer, Arizona white-tailed deer, or fantail deer
O. v. dakotensis – Dakota
white-tailed deer or northern plains white-tailed deer (most northerly
distribution, rivals the northern white-tailed deer in size)
O. v. nemoralis – (Central America, round the Gulf of Mexico to Surinam in South America; further restricted from Honduras to Panama)
O. v. peruvianus – South American white-tailed deer or Andean white-tailed deer (most southerly distribution in Peru and possibly Bolivia)
O. v. tropicalis – Peru and Ecuador (possibly Colombia)
O. v. ustus – Ecuador (possibly southern Colombia and northern Peru)
Range map of subspecies
North America
Central and South America
White-tailed deer buck seen in Missoula, Montana
Description
Female with tail in alarm posture
The deer's coat is a reddish-brown in the spring and summer and turns
to a grey-brown throughout the fall and winter. The deer can be
recognized by the characteristic white underside to its tail. It raises
its tail when it is alarmed to warn the predator that it has been
detected.[8] A population of white-tailed deer in New York is entirely white (except for areas like their noses and toes)—not albino—in color. The former Seneca Army Depot in Romulus, New York, has the largest known concentration of white deer.
An indication of a deer age is the length of the snout and the color of
the coat, with older deer tending to have longer snouts and grayer
coats. Strong conservation efforts have allowed white deer to thrive
within the confines of the depot. White-tailed deer's horizontally slit
pupils allow for good night vision and color vision during the day.
Size and weight
Close up of female's head
The white-tailed deer is highly variable in size, generally following Bergmann's rule
that the average size is larger farther away from the Equator. North
American male deer (also known as a buck) usually weigh 68 to 136 kg
(150 to 300 lb),[9]
but mature bucks over 180 kg (400 lb) have been recorded in the
northernmost reaches of their native range, specifically, Minnesota and
Ontario. In 1926, Carl J. Lenander, Jr., took a white-tailed buck near
Tofte, MN, that weighed 183 kg (403 lb) after it was field-dressed
(internal organs and blood removed) and was estimated at 232 kg (511 lb)
when alive.[10]
The female (doe) in North America usually weighs from 40 to 90 kg (88
to 198 lb). White-tailed deer from the tropics and the Florida Keys are
markedly smaller-bodied than temperate populations, averaging 35 to
50 kg (77 to 110 lb), with an occasional adult female as small as 25 kg
(55 lb).[11] White-tailed deer from the Andes
are larger than other tropical deer of this species, and have thick,
slightly woolly looking fur. Length ranges from 95 to 220 cm (37 to
87 in), including a tail of 10 to 37 cm (3.9 to 14.6 in), and the
shoulder height is 53 to 120 cm (21 to 47 in).[12][13] Including all races, the average summer weight of adult males is 68 kg (150 lb) and is 45.3 kg (100 lb) in adult females.[14]
Deer have dichromatic (two-color) vision with blue and yellow primaries;[15] humans normally have trichromatic vision. Thus, deer poorly distinguish the oranges and reds that stand out so well to humans.[16]
This makes it very convenient to use deer-hunter orange as a safety
color on caps and clothing to avoid accidental shootings during hunting
seasons.
Antlers
Male white-tailed deer
Males regrow their antlers every year. About one in 10,000 females also has antlers, although this is usually associated with freemartinism.[17]
Bucks without branching antlers are often termed "spikehorn", "spiked
bucks", "spike bucks", or simply "spikes/spikers". The spikes can be
quite long or very short. Length and branching of antlers are determined
by nutrition, age, and genetics. Rack growth tends to be very important
from late spring until about a month before velvet sheds. Healthy deer
in some areas that are well-fed can have eight-point branching antlers
as yearlings (1.5 years old).[18]
The number of points, the length, or thickness of the antlers is a
general indication of age, but cannot be relied upon for positive aging.
Some say spiked-antler deer should be culled from the population to
produce larger branching antler genetics (antler size does not indicate
overall health), and some bucks' antlers never will be wall trophies.
Good antler-growth nutritional needs (calcium) and good genetics combine
to produce wall trophies in some of their range.[19]
Spiked bucks are different from "button bucks" or "nubbin' bucks", that
are male fawns and are generally about six to nine months of age during
their first winter. They have skin-covered nobs on their heads. They
can have bony protrusions up to a half inch in length, but that is very
rare, and they are not the same as spikes.
White-tailed bucks with antlers still in velvet, August 2011
Antlers begin to grow in late spring, covered with a highly
vascularised tissue known as velvet. Bucks either have a typical or
atypical antler arrangement. Typical antlers are symmetrical and the
points grow straight up off the main beam. Atypical antlers are
asymmetrical and the points may project at any angle from the main beam.
These descriptions are not the only limitations for typical and
atypical antler arrangement. The Boone and Crockett
or Pope and Young scoring systems also define relative degrees of
typicality and atypicality by procedures to measure what proportion of
the antlers is asymmetrical. Therefore, bucks with only slight asymmetry
are scored as "typical". A buck's inside spread can be from 3 to 25 in
(8–64 cm). Bucks shed their antlers when all females have been bred,
from late December to February.
Ecology
White-tailed deer are generalists and can adapt to a wide variety of habitats.[20] The largest deer occur in the temperate regions of Canada and United States. The northern white-tailed deer (O. v. borealis), Dakota white-tailed deer (O. v. dacotensis), and northwest white-tailed deer (O. v. ochrourus)
are some of the largest animals, with large antlers. The smallest deer
occur in the Florida Keys and in partially wooded lowlands in the neotropics.
Although most often thought of as forest animals depending on
relatively small openings and edges, white-tailed deer can equally adapt
themselves to life in more open prairie, savanna woodlands, and sage
communities as in the Southwestern United States and northern Mexico.
These savanna-adapted deer have relatively large antlers in proportion
to their body size and large tails. Also, a noticeable difference exists
in size between male and female deer of the savannas. The Texas
white-tailed deer (O. v. texanus), of the prairies and oak
savannas of Texas and parts of Mexico, are the largest savanna-adapted
deer in the Southwest, with impressive antlers that might rival deer
found in Canada and the northern United States. Populations of Arizona (O. v. couesi) and Carmen Mountains (O. v. carminis) white-tailed deer inhabit montane mixed oak and pine woodland communities.[21]
The Arizona and Carmen Mountains deer are smaller, but may also have
impressive antlers, considering their size. The white-tailed deer of the
Llanos region of Colombia and Venezuela (O. v. apurensis and O. v. gymnotis) have antler dimensions similar to the Arizona white-tailed deer.
White-tailed deer during late winter
In some western regions of the United States and Canada, the white-tailed deer range overlaps with those of the mule deer. White-tail incursions in the Trans-Pecos region of Texas have resulted in some hybrids. In the extreme north of the range, their habitat is also used by moose in some areas. White-tailed deer may occur in areas that are also exploited by elk
(wapiti) such as in mixed deciduous river valley bottomlands and
formerly in the mixed deciduous forest of eastern United States. In
places such as Glacier National Park in Montana and several national parks in the Columbian Mountains (Mount Revelstoke National Park) and Canadian Rocky Mountains, as well as in the Yukon Territory (Yoho National Park and Kootenay National Park), white-tailed deer are shy and more reclusive than the coexisting mule deer, elk, and moose.
Central American white-tailed deer prefer tropical and subtropical dry broadleaf forests, seasonal mixed deciduous forests, savanna, and adjacent wetland habitats over dense tropical and subtropical moist broadleaf forests.
South American subspecies of white-tailed deer live in two types of
environments. The first type, similar to the Central American deer,
consists of savannas, dry deciduous forests, and riparian corridors that
cover much of Venezuela and eastern Colombia.[22]
The other type is the higher elevation mountain grassland/mixed forest
ecozones in the Andes Mountains, from Venezuela to Peru. The Andean
white-tailed deer seem to retain gray coats due to the colder weather at
high altitudes, whereas the lowland savanna forms retain the reddish
brown coats. South American white-tailed deer, like those in Central
America, also generally avoid dense moist broadleaf forests.
Since the second half of the 19th century, white-tailed deer have been introduced to Europe.[23] A population in the Brdy area remains stable today.[24] In 1935, white-tailed deer were introduced to Finland. The introduction was successful, and the deer have recently begun spreading through northern Scandinavia and southern Karelia,
competing with, and sometimes displacing, native species. The current
population of some 30,000 deer originated from four animals provided by Finnish Americans from Minnesota.
Diet
White-tailed deer eat large amounts of food, commonly eating legumes and foraging on other plants, including shoots, leaves, cacti (in deserts), prairie forbs,[25] and grasses. They also eat acorns, fruit, and corn. Their special stomachs allow them to eat some things humans cannot, such as mushrooms and poison ivy.
Their diets vary by season according to availability of food sources.
They also eat hay, grass, white clover, and other foods they can find in
a farm yard. Though almost entirely herbivorous, white-tailed deer have
been known to opportunistically feed on nesting songbirds, field mice,
and birds trapped in mist nets, if the need arises.[26]
A grown deer can eat around 2,000 lb (910 kg) of vegetable matter
annually. A foraging area around 20 deer per square mile can start to
destroy the forest environment.[27]
The white-tailed deer is a ruminant,
which means it has a four-chambered stomach. Each chamber has a
different and specific function that allows the deer to eat a variety of
different foods, digesting it at a later time in a safe area of cover.
The stomach hosts a complex set of microbes that change as the deer's
diet changes through the seasons. If the microbes necessary for
digestion of a particular food (e.g., hay) are absent, it will not be
digested.[28]
Predators
Several natural predators of white-tailed deer occur. Wolves, cougars, American alligators, jaguars
(in the tropics), and humans are the most effective natural predators
of white-tailed deer. These predators frequently pick out easily caught
young or infirm deer (which is believed to improve the genetic stock of a
population), but can and do take healthy adults of any size. Bobcats, Canada lynx, bears, wolverines, and packs of coyotes
usually prey mainly on fawns. Bears may sometimes attack adult deer,
while lynxes, coyotes, and wolverines are most likely to take adult deer
when the ungulates are weakened by harsh winter weather.[12] Many scavengers rely on deer as carrion, including New World vultures, raptors, foxes, and corvids. Few wild predators can afford to be picky and any will readily consume deer as carrion. Records exist of American crows attempting to prey on white-tailed deer fawns by pecking around their face and eyes, though no accounts of success are given.[29] Occasionally, both golden and bald eagles may capture deer fawns with their talons.[30] In one case, a golden eagle was filmed in Illinois unsuccessfully trying to prey on a large mature white-tailed deer.[31]
White-tailed deer typically respond to the presence of potential
predators by breathing very heavily (also called blowing) and fleeing.
When they blow, the sound alerts other deer in the area. As they run,
the flash of their white tails warns other deer. This especially serves
to warn fawns when their mother is alarmed.[32] Most natural predators of white-tailed deer hunt by ambush, although canids may engage in an extended chase, hoping to exhaust the prey. Felids
typically try to suffocate the deer by biting the throat. Cougars and
jaguars will initially knock the deer off balance with their powerful
forelegs, whereas the smaller bobcats and lynxes will jump astride the
deer to deliver a killing bite. In the case of canids and wolverines,
the predators bite at the limbs and flanks, hobbling the deer, until
they can reach vital organs and kill it through loss of blood. Bears,
which usually target fawns, often simply knock down the prey and then
start eating it while it is still alive.[33][34]
Alligators snatch deer as they try to drink from or cross bodies of
water, grabbing them with their powerful jaws and dragging them into the
water to drown.[35]
Most primary natural predators of white-tailed deer have been basically extirpated in eastern North America, with a very small number of reintroduced red wolves, which are nearly extinct, around North Carolina and a small remnant population of Florida panthers, a subspecies of the cougar. Gray wolves,
the leading cause of deer mortality where they overlap, co-occur with
whitetails in northern Minnesota, Wisconsin, Michigan, and parts of
Canada.[32] This almost certainly plays a factor in the overpopulation issues with this species.[32]
Coyotes, widespread and with a rapidly expanding population, are often
the only major nonhuman predator of the species, besides an occasional domestic dog.[32] In some areas, American black bears are also significant predators.[33][34] In northcentral Pennsylvania, black bears were found to be nearly as common predators of fawns as coyotes.[36] Bobcats, still fairly widespread, usually only exploit deer as prey when smaller prey is scarce.[37]
Discussions have occurred regarding the possible reintroduction of gray
wolves and cougars to sections of the eastern United States, largely
because of the apparent controlling effect they have through deer
predation on local ecosystems, as has been illustrated in the
reintroduction of wolves to Yellowstone National Park and their controlling effect on previously overpopulated elk.[38]
However, due to the heavy urban development in much of the East and
fear for livestock and human lives, such ideas have ultimately been
rejected by local communities and/or by government services and have not
been carried through.[39][40][41]
In areas where they are heavily hunted by humans, deer run almost
immediately from people and are quite wary even where not heavily
hunted. In most areas where hunting may occur deer seem to develop an
acute sense of time and a fondness for metro parks and golf courses.
This rather odd occurrence is best noted in Michigan, where in the lower
peninsula around late August early September they begin to move out of
less developed areas in favor of living near human settlements.
The deer of Virginia can run faster than their predators and have been recorded at speeds of 75 km (47 mi) per hour;[42] this ranks them amongst the fastest of all cervids, alongside the Eurasian roe deer.
They can also jump 2.7 m (8.9 ft) high and up to 10 m (33 ft) in
length. When shot at, the white-tailed deer will run at high speeds with
its tail down. If frightened, the deer will hop in a zig-zag with its
tail straight up. If the deer feels extremely threatened, however, it
may charge the person or predator causing the threat, using its antlers
or, if none are present, its head to fight off the threat.
Forest alteration
In
certain parts of the eastern United States, high deer densities have
caused large reductions in plant biomass, including the density and
heights of certain forest wildflowers, tree seedlings, and shrubs.
Although they can be seen as a nuisance species, white tail deer also
play an important role in biodiversity.[43][44]
At the same time, increases in browse-tolerant grasses and sedges and
unpalatable ferns have often accompanied intensive deer herbivory.[45]
Changes to the structure of forest understories have, in turn, altered
the composition and abundance of forest bird communities in some areas.[46]
Deer activity has also been shown to increase herbaceous plant
diversity, particularly in disturbed areas, by reducing competitively
dominant plants;[47] and to increase the growth rates of important canopy trees, perhaps by increased nutrient inputs into the soil.[48]
In northeastern hardwood forests, high-density deer populations
affect plant succession, particularly following clear-cuts and patch
cuts. In succession without deer, annual herbs and woody plants are
followed by commercially valuable, shade-tolerant oak and maple. The
shade-tolerant trees prevent the invasion of less commercial cherry and
American beech, which are stronger nutrient competitors, but not as
shade tolerant. Although deer eat shade-tolerant plants and acorns, this
is not the only way deer can shift the balance in favor of nutrient
competitors. Deer consuming earlier-succession plants allows in enough
light for nutrient competitors to invade. Since slow-growing oaks need
several decades to develop root systems sufficient to compete with
faster-growing species, removal of the canopy prior to that point
amplifies the effect of deer on succession. High-density deer
populations possibly could browse eastern hemlock seedlings out of
existence in northern hardwood forests;[49]
however, this scenario seems unlikely, given that deer browsing is not
considered the critical factor preventing hemlock re-establishment at
large scales.[50]
Ecologists have also expressed concern over the facilitative
effect high deer populations have on invasions of exotic plant species.
In a study of eastern hemlock forests, browsing by white-tailed deer
caused populations of three exotic plants to rise faster than they do in
the areas which are absent of deer. Seedlings of the three invading
species rose exponentially with deer density, while the most common
native species fell exponentially with deer density, because deer were
preferentially eating the native species. The effects of deer on the
invasive and native plants were magnified in cases of canopy
disturbance.[51]
Methods for controlling deer populations
Several
methods have been developed in attempts to curb the population of
white-tailed deer, and these can be separated into lethal and nonlethal
strategies. Most common in the U.S is the use of extended hunting as
population control, as well as a way to provide natural meat for humans.[52]
In Maryland and many other states, a state agency sets regulations on
bag limits and hunting in the area depending on the deer population
levels assessed.[53]
Hunting seasons may fluctuate in duration, or restrictions may be set
to affect how many deer or what type of deer can be hunted in certain
regions. For the 2015–2016 white-tailed deer-hunting season, some areas
only allow for the hunting of antlerless white-tailed deer. These would
include young bucks and females, encouraging the culling of does which
would otherwise contribute to increasing populations via offspring
production.[52]
More refined than public hunting is a method referred to as sharpshooting by the Deer Task Force in the city of Bloomington, Indiana.
Sharpshooting can be an option when the area inhabited by the deer is
unfit for public hunting. This strategy may work in areas close to human
populations, since it is done by professional marksmen, and requires a
submitted plan of action to the city with details on the time and
location of the event, as well as number of deer to be culled.[54]
Another controversial method involves trapping the deer in a net
or other trap, and then administering a chemical euthanizing agent or
extermination by firearm. A main issue in questioning the humaneness of
this method is the stress that the deer endure while trapped and
awaiting extermination.[55]
Nonlethal methods include contraceptive injections, sterilization, and translocation of deer.[56]
While lethal methods have municipal support as being the most effective
in the short term, some opponents to this view suggest no significant
impacts of deer extermination on the populations occur.[57]
Opponents of contraceptive methods point out that fertility control
cannot provide meat and proves ineffective over time as populations in
open-field systems move about. Concerns are voiced that the
contraceptives have not been adequately researched for the effect they
could have on humans. Fertility control also does nothing to affect the
current population and the effects their grazing may be having on the
forest plant make-up.[58]
Translocation has been considered overly costly for the little
benefit it provides. Deer experience high stress and are at high risk of
dying in the process, putting into question its humaneness.[59] Another concern in using this method is the possible spread of chronic wasting disease found in the deer family and the lack of research on its effect on human populations.
Behavior
These bucks were pursuing a pair of does across the Loxahatchee River in Florida—the does lost them by entering a mangrove thicket too dense for the bucks' antlers.
Males compete for the opportunity of breeding females. Sparring among males determines a dominance hierarchy.[60]
Bucks attempt to copulate with as many females as possible, losing
physical condition, since they rarely eat or rest during the rut. The
general geographical trend is for the rut to be shorter in duration at
increased latitude. Many factors determine how intense the "rutting
season" will be; air temperature is a major one. Any time the
temperature rises above 40 °F (4 °C), the males do much less traveling
looking for females, else they will be subject to overheating or
dehydrating. Another factor for the strength in rutting activity is
competition. If numerous males are in a particular area, then they
compete more for the females. If fewer males or more females are
present, then the selection process will not need to be as competitive.
Females enter estrus, colloquially called the rut, in the autumn, normally in late October or early November, triggered mainly by the declining photoperiod. Sexual maturation of females depends on population density, as well as availability of food.[61]
Young females often flee from an area heavily populated with males.
Some does may be as young as six months when they reach sexual maturity,
but the average age of maturity is 18 months.[62] Copulation consists of a brief copulatory jump.[63][64]
Females give birth to one to three spotted young, known as fawns,
in mid- to late spring, generally in May or June. Fawns lose their
spots during the first summer and weigh from 44 to 77 lb (20 to 35 kg)
by the first winter. Male fawns tend to be slightly larger and heavier
than females. For the first four weeks, fawns are hidden in vegetation
by their mothers, who nurse them four to five times a day. This strategy
keeps scent levels low to avoid predators. After about a month, the
fawns[65]
are then able to follow their mothers on foraging trips. They are
usually weaned after 8–10 weeks, but cases have been seen where mothers
have continued to allow nursing long after the fawns have lost their
spots (for several months, or until the end of fall) as seen by
rehabilitators and other studies. Males leave their mothers after a year
and females leave after two.
Bucks are generally sexually mature at 1.5 years old and begin to breed even in populations stacked with older bucks.
White-tailed deer have many forms of communication involving sounds,
scent, body language, and marking. In addition to the aforementioned
blowing in the presence of danger, all white-tailed deer are capable of
producing audible noises unique to each animal. Fawns release a
high-pitched squeal, known as a bleat, to call out to their mothers.[66]
This bleat deepens as the fawn grows until it becomes the grunt of the
mature deer, a guttural sound that attracts the attention of any other
deer in the area. A doe makes maternal grunts when searching for her
bedded fawns.[66]
Bucks also grunt, at a pitch lower than that of the doe; this grunt
deepens as the buck matures. In addition to grunting, both does and
bucks also snort, a sound that often signals an imminent threat. Mature
bucks also produce a grunt-snort-wheeze pattern, unique to each animal,
that asserts its dominance, aggression, and hostility.[66]
Another way white-tailed deer communicate is through the use of their
white tail. When spooked, it will raise its tail to warn the other deer
in the immediate area.
Marking
White-tailed deer possess many glands that allow them to produce scents,
some of which are so potent they can be detected by the human nose.
Four major glands are the preorbital, forehead, tarsal, and metatarsal
glands. Secretions from the preorbital glands
(in front of the eye) were thought to be rubbed on tree branches, but
research suggests this is not so. Scent from the forehead or
sudoriferous glands (found on the head, between the antlers and eyes) is
used to deposit scent on branches that overhang "scrapes" (areas scraped by the deer's front hooves prior to rub-urination).
The tarsal glands are found on the upper inside of the hock (middle
joint) on each hind leg. Scent is deposited from these glands when deer
walk through and rub against vegetation. These scrapes are used by bucks
as a sort of "sign-post" by which bucks know which other bucks are in
the area, and to let does know a buck is regularly passing through the
area—for breeding purposes. The scent from the metatarsal glands, found
on the outside of each hind leg, between the ankle and hooves, may be
used as an alarm scent. The scent from the interdigital glands, which
are located between the hooves of each foot, emit a yellow waxy
substance with an offensive odor. Deer can be seen stomping their hooves
if they sense danger through sight, sound, or smell; this action leaves
an excessive amount of odor for the purpose of warning other deer of
possible danger.[67]
Throughout the year, deer rub-urinate,
a process during which a deer squats while urinating so urine will run
down the insides of the deer's legs, over the tarsal glands, and onto
the hair covering these glands. Bucks rub-urinate more frequently during
the breeding season.[68] Secretions from the tarsal gland mix with the urine and bacteria to produce a strong-smelling odor.[69]
During the breeding season, does release hormones and pheromones that
tell bucks a doe is in heat and able to breed. Bucks also rub trees and
shrubs with their antlers and heads during the breeding season, possibly
transferring scent from the forehead glands to the tree, leaving a
scent other deer can detect.[70]
Sign-post marking (scrapes and rubs) is a very obvious way white-tailed deer communicate.[70]
Although bucks do most of the marking, does visit these locations
often. To make a rub, a buck uses his antlers to strip the bark off
small-diameter trees, helping to mark his territory and polish his
antlers. To mark areas they regularly pass through, bucks make scrapes.
Often occurring in patterns known as scrape lines, scrapes are areas
where a buck has used his front hooves to expose bare earth. They often
rub-urinate into these scrapes, which are often found under twigs that
have been marked with scent from the forehead glands.[citation needed]
Human interactions
Rescued fawn being kept as a pet in a farm near Cumaral, Colombia
By the early 20th century, commercial exploitation and unregulated hunting had severely depressed deer populations in much of their range.[71] For example, by about 1930, the U.S. population was thought to number about 300,000.[72] After an outcry by hunters and other conservation ecologists,
commercial exploitation of deer became illegal and conservation
programs along with regulated hunting were introduced. In 2005,
estimates put the deer population in the United States at around 30
million.[73]
Conservation practices have proved so successful, in parts of their
range, the white-tailed deer populations currently far exceed their
cultural carrying capacity and the animal may be considered a nuisance.[74][75]
A reduction in natural predators (which normally cull young, sick, or
infirm specimens) has undoubtedly contributed to locally abundant
populations.
At high population densities, farmers can suffer economic damage by deer feeding on cash crops, especially in corn and orchards.
It has become nearly impossible to grow some crops in some areas unless
very burdensome deer-deterring measures are taken. Deer are excellent
fence-jumpers, and their fear of motion and sounds meant to scare them
away is soon dulled. Timber harvesting and forest clearance have
historically resulted in increased deer population densities,[76][77]
which in turn have slowed the rate of reforestation following logging
in some areas. High densities of deer can have severe impacts on native
plants and animals in parks and natural areas; however, deer browsing
can also promote plant and animal diversity in some areas.[78][79]
Deer can also cause substantial damage to landscape plants in suburban
areas, leading to limited hunting or trapping to relocate or sterilize
them. In parts of the Eastern US with high deer populations and
fragmented woodlands, deer often wander into suburban and urban habitats
that are less than ideal for the species.
Hunting
White-tailed deer have long been hunted as game, for pure sport and for their commodities.
Venison, or deer meat, is a very natural and nutritious form of animal
protein that can be obtained through responsible and regulated deer
hunting. In some areas where their populations are very high, they are
considered a pest, and hunting is used as a method to control it.
Many
keep white-tailed deer as pets. They are very smart, affectionate,
curious and playful. However, on multiple occasions, during mating
season, bucks kept as pets were very aggressive and resulted in severe
injuries in their owners. Some areas ban the keeping of white-tailed
deer in captivity, while others advocate the trapping and keeping of
wild deer as an alternative to hunting due to high populations.
However, this is illegal across many U.S. states, as it is considered
dangerous; a white-tailed deer's large antlers can impale and kill if
that is what the deer intends. Any deer found being held captive will be
killed by law enforcement officers in order to prevent the spread of
any diseases the deer may have obtained.[80]
Motor
vehicle collisions with deer are a serious problem in many parts of the
animal's range, especially at night and during rutting season, causing
injuries and fatalities among both deer and humans. Vehicular damage can
be substantial in some cases.[81] In the United States, such collisions increased from 200,000 in 1980 to 500,000 in 1991.[82]
By 2009, the insurance industry estimated 2.4 million deer–vehicle
collisions had occurred over the past two years, estimating damage cost
to be over 7 billion dollars and 300 human deaths. Despite the alarming
high rate of these accidents, the effect on deer density is still quite
low. Vehicle collisions of deer were monitored for two years in
Virginia, and the collective annual mortality did not surpass 20% of the
estimated deer population.[83]
Many techniques have been investigated to prevent road-side mortality. Fences or road under- or over- passes have been shown to decrease deer-vehicle collisions, but are expensive and difficult to implement on a large scale.[84][85] Roadside habitat modifications could also successfully decrease the number of collisions along roadways.[85]
An essential procedure in understanding factors resulting in accidents
is to quantify risks, which involves the driver's behavior in terms of safe speed
and ability to observe the deer. They suggest reducing speed limits
during the winter months when deer density is exceptionally high would
likely reduce deer-vehicle collisions, but this may be an impractical
solution.[84]
Diseases
Another
issue that exists with high deer density is the spreading of infectious
diseases. Increased deer populations lead to increased transmission of
tick-borne diseases, which pose a threat to human health, to livestock,
and to other deer. Deer are the primary host and vector for the adult
black-legged tick, which transmits the Lyme disease bacterium to humans.[86]
Lyme disease is the most common vector-borne disease in the country and
is found in twelve states in Eastern America. In 2009, it affected more
than 38,000 people. Furthermore, the incidence of Lyme disease seems to
reflect deer density in the eastern United States, which suggests a
strong correlation. White-tailed deer also serve as intermediate hosts
for many diseases that infect humans through ticks, such as Rocky Mountain spotted fever.[82][83]
Newer evidence suggests the white footed mouse is the most significant vector.[87][88]
Cultural significance
Odocoileus virginianus skull, part of an exhibition on the cultural artifacts of the Cora people of Western Mexico.
Climate change is affecting the white tailed deer by changing their migration patterns and increasing their population size.[89][90] This species of deer is restricted from moving northward due to cold harsh winters.[91][89][92][93]
Consequently, as climate change warms up the Earth, these deer are
allowed to migrate further north which will result in the populations of
the white-tailed deer increasing.[90][91][89] The predicted change in deer populations due to climate change were expected to increase by 40% between 1970 and 1980.[90] Between 1980 and 2000 in a study by Dawe and Boutin, presence of white-tailed deer in Alberta, Canada was driven primarily by changes in the climate.[90] Populations of white tailed deer have also moved anywhere from 50–250 km north of the eastern Alberta study site. Another study by Kennedy-Slaney, Bowman, Walpole, and Pond found that if our CO2 emissions remained the same, global warming resulting from the increased greenhouse gases in our atmosphere will allow white-tailed deer to survive further and further north by 2100.[91] This study also showed that an increase in deer populations will affect populations of other species.
However,
there are also negative effects resulting from climate change. The
species is vulnerable to diseases that are more prevalent in the summer.[89]
Insects carrying these diseases are usually killed during the first
snowfall. However, as time goes on, they will be able to live longer
than they used to meaning the deer are at higher risk of getting sick.
It is possible that this will increase the deers’ mortality rate from
disease.[94] Examples of these diseases are hemorrhagic disease (HD), epizootic hemorrhagic disease and bluetongue viruses, which are transmitted by biting midges.[91] The hotter summers, longer droughts, and more intense rains creates the perfect environment for the midges to thrive in.[95] Ticks also thrive in warmer weather heat results in faster development in all of their life stages.[95]
18 different species of tick infest white-tailed deer in the United
States alone. Ticks are parasitic to white-tailed deer transmit
diseases causing irritation, anemia, and infections.[95]
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