Giraffe SPECIES PROFILE - dpipwe
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
SPECIES PROFILE
Giraffe
Giraffa camelopardalis
Image: Herbert Bieser
May 2021
Author: H. Hesterman, BSc. MSc. PhD.
Table of Contents 1.0 Summary ................................................................................................................................ 1 1.1 Scientific Classification...................................................................................................... 2 1.2 Common Name .................................................................................................................. 2 1.3 Subspecies .......................................................................................................................... 2 1.4 Taxonomy........................................................................................................................... 3 2.0 Description ............................................................................................................................. 3 3.0 Conservation and Legal Status............................................................................................... 6 3.1 Legal Status ........................................................................................................................ 8 4.0 Life History ............................................................................................................................ 8 5.0 Habitat Requirements and Preferences ................................................................................ 10 6.0 Natural Geographic Range ................................................................................................... 11 7.0 Introduced Geographic Range ............................................................................................. 12 8.0 Potential Distribution in Tasmania ...................................................................................... 13 9.0 Diet and Feeding Behaviour ................................................................................................ 15 10.0 Social Behaviour and Groupings ......................................................................................... 16 11.0 Natural Predators and Disease ............................................................................................. 17 11.1 Predators ....................................................................................................................... 17 11.2 Disease .......................................................................................................................... 17 12.0 Threats to Human Safety ..................................................................................................... 18 12.1 Injury ............................................................................................................................ 18 12.2 Disease .......................................................................................................................... 18 13.0 History as a Pest ................................................................................................................... 19 14.0 Potential Impact in Tasmania............................................................................................... 19 15.0 Previous Risk Assessments .................................................................................................. 20 16.0 Risk Management ................................................................................................................ 20 17.0 References ............................................................................................................................ 21 This pest risk assessment was developed in accordance with Policy and Procedures for the Import, Movement and Keeping of Vertebrate Wildlife in Tasmania (DPIPWE 2011). These set out conditions and restrictions for importation of controlled animals pursuant to S32 of the Nature Conservation Act 2002. This document was prepared for DPIPWE use within the Department only.
1.0 Summary
Giraffe (Giraffa camelopardalis) are tropical megaherbivores endemic to Africa and are the world’s
tallest land mammal. They are specialised browsers adapted to feeding on tall woody plants and
forbs and inhabit the sub-Saharan grassland biome. The species’ wide natural distribution has
undergone a major decline over the last century, going extinct in seven previously reported
countries. Reduction and fragmentation of their former range is associated with anthropogenic
habitat loss and degradation throughout the continent. Ecological changes and conversion of land
are likely to continue with Africa having the fastest human population growth rate in the world.
In 2016 G. camelopardalis was categorised as Vulnerable by IUCN based on a continuing decrease
in collective numbers, which have nearly halved over the last 30 years. Main threats are cited as
habitat loss, civil unrest, poaching and ecological change. Populations are subject to different
pressures across their broad distribution and those remaining are fragmented and genetically
distinct, marking additional concerns for conservation. Decreases are most evident in east and
central regions where populations include the Critically Endangered Nubian (G.c. antiquorum) and
Kordofan (G.c. camelpardalis) subspecies. Approximately 70% of Giraffe live outside protected
areas including private land where they can be legally farmed. The species has been hunted for
centuries, but only recently has the trade in parts begun to be monitored, since the species’ was
listed on CITES in late 2019.
In situ conservation measures include effective habitat management in conjunction with community
engagement, using initiatives to protect and balance critical resources (land, water) between wildlife
and people via actions such as exclusion fencing. Translocations of Giraffe are commonplace and
used to support tourism and farming enterprises and bolster animal numbers in the wild. There are
no free-ranging populations outside of the species’ natural distribution and they are not listed as a
pest.
Giraffe are a natural curiosity and have been widely represented in captivity around the world for
centuries. In Australia, they have been present in zoos since the mid-1920s, and under the EPBC
Act 1999 the species is permitted for live import to the country for such purpose. There is no formal
risk assessment for G. camelopardalis in Australia.
As a key component of information to conduct a risk assessment for Tasmania, CLIMATCH
modelling was applied to compare climatic conditions throughout Australia with Giraffes’ natural
distribution in Africa over the last 1000 years. Results indicated environmental conditions would
be least favourable for this species in Tasmania because of the state’s cool temperate climate.
Giraffe have evolved to withstand extreme levels of heat and radiation in an arid environment which
makes them especially vulnerable to hypothermia, and mass deaths occur after cold and damp
weather episodes in the wild. It is highly unlikely escaped any animals that escaped in Tasmania
could establish free living populations because they would be rapidly detected and removed or
perish from environmental exposure. Based on their biology, behaviour and habits Giraffe are not
envisaged to impact on native species, environmental assets or primary industries, damage property
or infrastructure, nor represent a threat to humans.
Benefits of importing Giraffe to approved zoological facilities in Tasmania include tourism,
education, awareness raising and participating in conservation opportunities for this vulnerable
keystone species.
Page 1 of 26
Name and Taxonomy
1.1 Scientific Classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Giraffidae
Genus: Giraffa
Species: Giraffa camelopardalis; see notes below
1.2 Common Name
Giraffe
1.3 Subspecies
Giraffe nomenclature remains subject of an unresolved debate at time of this submission
(Bercovitch et al 2018; Fennessy et al 2018). The IUCN Giraffe and Okapi Specialist Group
currently lists one (1) species G. camelopardalis and nine (9) subspecies (Muller et al 2016, 2018)
pending a formal reassessment of taxonomy based on new genetic research. Traditionally alpha
taxonomy was based on morphological and geographical distinctions between populations, but this
new approach indicates four (4) distinct species and seven (7) subspecies (Fennessy et al 2017).
For a comparison of these two conventions, see Table 1.
For this Species Profile, the status quo convention will be maintained as per IUCN (Muller et al
2016), and reference made to other considerations where relevant.
Table 1: Comparison of currently accepted Giraffe Alpha Taxonomies
Page 2 of 26
1.4 Taxonomy
Giraffe are mammals of the Grand Order Ungulata, and as “even-toed” animals placed within the
Artiodactyla Order, represented by over 90% of extant hoofed mammals. The artiodactyls are
further categorised based on their digestive system, and Giraffe are placed akin to browsers such as
cattle, sheep and deer (Ruminantia). Within this group they are further divided to Infraorder Pecora,
being those that are characterised by cranial appendages. This group of ‘horn bearing ruminants’
are represented today by five Families, some of which e.g. Bovidae, is comprised of nearly 150
different species. By comparison, the Family Giraffidae contains only two living members – the
Giraffe and the Okapi (Okapia johnstoni), both endemic to Africa. These species shared a common
ancestor during the Oligocene (34–23million years ago) (Hassanin and Douzery, 2003) but occupy
a completely separate distribution and habitat, with Okapi being endemic to the dense, closed
forests of the Democratic Republic of Congo (Mallon et al 2015).
Based on their antler like appendages, (known as ossicones), Giraffe were assigned to the Genus
Cervus (Cervus camelopardalis, Linneus 1758) alongside members of the deer family until the
1970s but were reclassified soon after into their own Genus (Giraffa camelopardalis, Brisson 1762)
soon after because they do not shed their ‘horns’. Taxonomy thereafter was based on geographical
distribution of populations and morphological traits such as coat patterning (Figure 1) and numbers
of ossicones (reviewed in Schorrocks 2016). More recently, however as outlined in Section 2.1;
genetic analyses have revealed speciation and divergence (Fennesy et al 2017; Winter et al 2018),
prompting the need for a review of alpha taxonomy.
Giraffe populations were once widespread throughout the African continent and likely more
contiguous, than those present today which are confined to sub-Saharan Africa. Although not all
groups are geographically isolated from each other, gene flow research indicates hybridisation
events are rare in the wild (Winter et al 2018) despite occurring in captivity (EAZA 2004; AZA
2016). The extent of inter- or intra-specific hybridisation that naturally occurs among wild Giraffe
populations is uncertain. This has obvious ramifications for future conservation management of
Giraffe, as will future taxonomy agreement on the assessments of populations in different parts of
their range (see Section 4.0, Conservation).
2.0 Description
Giraffe are easily recognisable for their greatly elongated neck1 and legs and immense body size.
They are the world’s tallest mammal, with adults attaining up to 3.5m high at the shoulder and an
average total height of around 5.5m for males and 4.5m for females. This sexual dimorphism in
body size is also reflected in their bodyweight, with an average of around 800kg (703-950kg) for
females and ~1200kg (973-1395kg) for males (Betelsen 2015; Schorrocks 2016; SDZWA 2021).
Despite the Giraffe’s enormous body size, their distinctive patterning may help to camouflage them
against predators in their natural habitat. The pattern and colouration are particularly effective
camouflage for young, vulnerable calves which need to remain hidden for the first few weeks of
life (Schorrocks 2016; Fennesy et al 2020).
The Giraffe’s recognisable pelage is a mosaic of large gold, tan and red to dark brown coloured
blocks surrounded by lighter borders. Coat patches contain high level of sweat glands and dilation
1
There are seven vertebrae as for all other mammals, but these cervical structures are enlarged at up to 25cm long.
Page 3 of 26
of blood vessels underlying these darker spots may assist coping with the extreme heat and radiation
(Schorrocks 2016). For juveniles, the presence of larger, irregular, and more round spots is
associated with increased survival rates (Lee et al 2018), although the mechanism - reduced
predation or improved thermoregulation – has not been determined. Distinct differences are seen
in coat colouration and patterning between populations in different parts of Africa, and it has been
suggested that lighter coloured animals may be better adapted for hotter drier habitats (Kingdon
1989 cited in Schorrocks 2016).
The height of Giraffe enables them to feed on vegetation beyond the reach of most other herbivores.
Specialised features – such as greater articulation of the skull and their elongated prehensile, sticky
tongue increase browsing reach even further (Figure 2) (Schorrocks 2016). The skull of the giraffe
is elongated and contains teeth similar to other ruminants, characterised by loss of the upper incisors
and canines and molars adapted to grinding vegetation. Their teeth are specialised for browsing
and are low crowned (brachydont), unlike those of grazing ungulates whose teeth are evolved to
withstand abrasive silica components found in grasses (Clauss et al 2007).
Giraffe usually feed on tall trees or bushes and because their neck is too short to reach the ground
they need to splay their legs or kneel to access lower forage or water (Figure 2). When animals
are upright the heart elevates each column of blood to the brain over a distance of up to two metres.
Cardiovascular anatomy is similar to other ungulates but Giraffe have a specially adapted
circulatory system that allows them to regulate gravitational extremes in blood flow and pressure
resulting from their large and unusual body morphology (Bertelsen 2015; Schorrocks 2016).
Figure 1: An example of Giraffe subspecies classification based on distribution of populations and coat patterning,
with phylogenetic relationships shown at right (from Brown et al 2002 in Schorrocks 2016).
Page 4 of 26
The top of the head has distinct, horn like ossicones that end in a terminal knob (Figure 2). Up to
several pairs of ossicones may be present associated with different underlying parts of the skull2
but the parietal type is the only consistent form. These additional ossicones may form behind or in
front of the main pair and up to five pairs as well as the presence of lumpy outgrowths may be
present. Ossicones are covered in skin rather than the keratin sheath that defines a true horn; they
are also permanent, unlike the antlers of cervids which are shed each year. Ossicones are present
from birth, fuse with the skull by adulthood and continue to grow. In males these structures are
used as weapons in fighting and may be larger and appear more prominent with sparser covering
of hair (Furstenburg 2013; Schorrocks 2016; Fennesy et al 2020).
Giraffe locomote with a pacing gait common to camelids and some other long-legged animals.
When walking they swing both legs of one side forward at the same time. To stop the limbs
colliding at greater speeds they alternate front and rear limbs, moving the foreleg slightly back as
the hindlimb swings forward in a pace is more aptly termed a gallop. Impressively, they are
reported to attain speeds of up to 60km/hr and can maintain this velocity for five minutes or more.
At rest they fold their legs beneath them and keep the neck erect or tuck it back against their side,
but often sleep upright3 (Dagg 2014; Langman et al. 1982 in Schorrocks 2016).
Figure 2: Key identifying features of the Giraffe are its’ enormous size, elongated legs and neck and heavily
patterned coat. They must splay the forelegs wide (left) when feeding on low bushes or drinking because the length
2of the neck means their head cannot reach the ground. They have distinct horn type structures known as ossicones,
Ossicone number has also been used for identifying species found in different geographic locations (Schorrocks 2016)
3present from birth. Adaptions for feeding on tall vegetation include
Resting patterns are highly unusual - characterised by brief bouts of sleep during thethe
day ability
or night;to extend
and thoughtthe head
to be and necktovertically,
an adaptation antipredation
and a long,
(Tobler prehensile
& Schweirin 1996;sticky
Burger tongue (right).
et al 2020).
Image credits: Andreas Göllner (left), rjmcsorley (above)
Page 5 of 26
3.0 Conservation and Legal Status
Listed by the IUCN initially in 1996 as Lower Risk/Conservation Dependent, in 2016 G.
camelopardalis was reassessed and assigned to the Vulnerable category, based on a decrease
approaching 50% over the last three decades and continued decline in numbers (Muller et al 2016).
In late 2019, following pressure from non-government organisations concerned about the threat of
illegal hunting, Giraffe were finally listed on CITES (Appendix II) allowing for control and
monitoring of the ongoing trade in their parts. Passing of this legislation generated controversy
because key organisations i.e. IUCN and TRAFFIC did support the listing, citing a lack of evidence
that poaching is driving this international trade (Dunn et al 2021).
Giraffe have undergone a clear continent-wide decline throughout their endemic range of Africa.
Although distribution remains broad, significant range reduction and fragmentation has occurred
as a result of anthropogenic habitat loss or degradation (Section 4, Natural Distribution); and
potentially effects of disease and climate change (O’Conner et al 2019; Fennesy et al 2020). With
a broad distribution that spans more than 20 different countries in the sub-Saharan region,
populations are subject to varying pressures, but main threats are habitat loss, civil unrest, poaching
and ecological change (Muller et al 2016).
The latest population survey indicates around 70% of Giraffe live outside protected areas
(O’Connell et al 2019). Groups are found ranging in public and communal areas as well as private
lands, where they are allowed to be farmed. In South Africa they were recently reclassified as
livestock, creating concerns for future genetic preservation (Somers et al 2020). They are afforded
different levels of legal protection throughout their range but have been traditionally hunted for
centuries, with parts used for consumption, ornaments, and medicinal purposes and traded on a
local and international scale. A new study by Dunn et al (2021) confirms the impact of legal and
illegal hunting upon Giraffe differs markedly throughout their range and lends further merit to a
requirement for separate conservation assessment of populations.
Some Giraffe populations are considered to be stable or even increasing in number, while others
are in clear decline (Muller et al 2016; Fennesy et al 2018). The outcome of published assessments
at the species and subspecies level differ in terms of trends as well as proposed or determined
individual conservation status because of as yet unresolved taxonomy (refer Section 2.3). The
IUCN provides a general overview of the species which indicates decreasing numbers in Eastern
and Central Africa and increasing numbers in South and West Africa. At the subspecies level this
variance in population is upheld (G. c. antiquorum, G. c. camelopardalis, G. c. reticulata, G. c.
tippelskirchi decreasing; G. c. angolensis, G. c. giraffa, G. c. peralta, G. c. rothschildi increasing
and G. c. thornicrofti populations stable) with subspecies and their conservation assessments
summarised in Table 2, below.
Latest estimates indicate 97,500-11,000 Giraffe are left in the wild, and Southern and Masai Giraffe
populations (G.c. giraffa and G.c. tippelskirchi, respectively) account for nearly half of all
remaining animals (Muller et al 2018; GCF 2019). In sharp contrast, Nubian G.c. antiquorum and
Kordofan G.c. camelpardalis Giraffe number as few as 455 to 1400 mature individuals respectively
and are listed as “Critically Endangered”. The only subspecies not yet individually assessed - the
South African Giraffe (G.c. giraffa / G.g. giraffa) is also likely to qualify as “Critically Endangered”
based on declines exceeding 80% in the last 30 years (O’Connor et al 2019).
Page 6 of 26
Conservation measures for Giraffe vary by range country and region and are underpinned by
legislation and policies at a local and national scale. Actions taken include habitat management
and protection coupled with community engagement, and have led to some notable successes, for
example in South Africa (Muller et al 2016; Deacon & Tuchings 2018). Initiatives aim to help
protect and balance resources in the landscape and promote and support the economy e.g. through
use of effective fencing of areas. Successful programs have led to increase of Giraffe populations
in Niger where the first National Strategy was developed, with Kenya soon to implement its’ own
action plan for the species (Muller et al 2016).
Translocation of Giraffes between areas has been widely practiced within and between range
countries for many years to bolster populations and encourage enterprises such tourism and
farming; and in South Africa, ranchers have worked with officials to introduce their stock into
private and provincial game reserves (Deacon & Tuchings 2018). A lamentable lack of
documentation has led to a call for formal guidelines that will steer future translocation process
(Fennesy et al 2020). This is also considered necessary for improved animal welfare, action
planning, implementing, and measuring outcomes (Berkovitch and Deacon 2015; Muller et al 2016,
2018). It is hoped that such information on translocations and private trade will be widely shared
and contribute toward future monitoring and conservation efforts (Muller et al 2016, 2018).
Table 2: Giraffe current conservation status noting different taxonomic conventions currently applied to categorise
species and subspecies (O’Conner et al 2019).
In 2016, an African-wide Giraffe Conservation Strategic Framework was developed as a ‘roadmap’
to help guide management and activities at a national level and assist in their implementation. It
recognises knowledge gaps, identifies actions and priorities and emphasises the importance of
improved engagement / collaboration with stakeholders (Fennessy et al 2016). The Giraffe
Conservation Foundation (https://giraffeconservation.org/) is a key player in this progressive
strategy, involved in increasing awareness of the species, securing and protecting habitat, and
working with local communities. Their in-situ research support is complemented by international
partnerships with renowned institutes such as San Diego Zoo Wildlife Alliance (SDZWA). Giraffe
have been present in zoos worldwide for centuries, but exports from the wild are no longer
Page 7 of 26commonplace. Today populations are collectively managed with a goal to be self-sustaining, and
the animals act as ambassadors for awareness and preservation of free-ranging Giraffe and their
habitat (AZA 2006; EAZA 2014).
3.1 Legal Status
In Australia, Giraffe are permitted for live import under the Environment Protection and
Biodiversity (EPBC) Act 1999 (https://www.legislation.gov.au/Details/F2017C00434) but
restricted for non-commercial purpose, such as by an approved zoological facility. No imports are
permitted into Australia other than from New Zealand institutes (ZAA 2020).
4.0 Life History
In the wild, female Giraffe are sexually mature by 4-5years of age and typically produce their first
calf by 6-7 years old, and males breed by 10 years old (Bercovitch and Berry 2009; Schorrocks et
al 2016). Under captive care, both sexes can produce young as early as their third year, but there
may be a behavioural component for young males which tend only sire offspring in the absence of
older, dominant bulls. Adults continue to produce young for most of their life – females calve as
late as 24 years of age in the wild, and 27 years old in captivity (Burgess 2004; EAZA 2006;
Bercovitch and Berry 2009; Furstenberg 2013; AZA 2014).
Females give birth at any time throughout the year, an aseasonal pattern that is typical of tropical
ungulates. In wild populations peak mating occurs during the wet season resulting in a peak of
births during dry months, a timing correlated with rainfall, temperature, and food availability to
best benefit survival of offspring (Deacon et al 2015; Schorrocks 2016). Giraffe have a complex,
but loose social system (Section 11) and males usually roam between herds seeking mating
opportunities (Bond et al 2021). There are seasonal differences in association between the sexes
which has been suggested as another factor contributing to the temporal breeding pulse (Hart et al
2021).
Giraffe are known to be polygynous but there is little understood about mate choice or success in
this breeding strategy (Bercovitch & Deacon 2015). Bulls investigate all cows within a herd,
focussing on those entering oestrus. They nuzzle the cow’s rump to stimulate micturition then
sample chemicals in her urine by raising their head and upper lip in a classic flehmen response.
Males follow, guard and feed near females in oestrus, which lasts around two weeks (average 15
days). Bulls engage in more sparring together at this time, and a peak in fighting behaviour,
androgen levels and stress hormones occurs when cows are in their fertile window (Scheijen et al
2020). Females are usually only receptive for a single day and mounting and copulation by the
male lasts only a few seconds with no continued association between the pair thereafter (Seeber et
al 2012; Bertelsen 2015; Schorrocks 2016).
Embryonic growth is slow, and the gestation period lasts around 15 months (420-468 days)
(Bertelsen 2015). Giraffe nearly always produce a single calf, and while twins are occasionally
reported for the wild and captivity, cases tend to be associated with abortion, stillbirth, or dystocia
and both offspring rarely survive. Pregnant females leave the herd to give birth alone as they enter
late stage gestation (EAZA 2006; Deacon et al 2015; Schorrocks 2016; Scheijen et al 2020;
Furstenburg 2013). They calve from a standing position and the neonate falls to the ground but is
highly precocial - standing as soon as 5-20 minutes after birth and beginning to suckle and run
within an hour (Dagg 2014 in Fennessy et al 2020). The size of a newborn Giraffe is 1.5-1.8 metres
Page 8 of 26shoulder height, with a bodyweight of between 60 - 100 kilograms (Skinner and Hall 1975; Bertelsen 2015; Schorrocks 2016). The dam remains isolated from the herd for at least a week after giving birth, and their offspring spends most of its’ time lying concealed near cover such as long grass or bushes. Females leave their young calf alone for hours and only return to nurse it several times a day; however the mother remains nearby and vigilant, ready to defend her offspring from predators (reviewed in Lee et al 2017, Schorrocks 2016). By its’ second week the calf is more active and mother and young begin to associate with other females that have offspring of a similar age. A single female takes turn to guard young in this ‘calving pool’ while others to range and forage. Synchronisation of calving within herds may also serve to reduce offspring predation through either increased number of young present (satiation) or heightened vigilance of such groups (Schorrocks 2016). An unusual trait that has been observed in Giraffe, but only recently confirmed through hormonal profiling and monitoring (Deacon et al 2015), is the ability of females to conceive while they are nursing young calves. Lactation does not suppress ovulation, and several months after giving birth they come back into oestrus. Cows will cycle every two weeks until they become pregnant again, leading to a truncated interbirth interval of 19-22 months (Bercovitch and Berry 2009; Bercovitch & Deacon 2015). This adaptation most likely evolved as a result of life history features such as aseasonality, slow embryo development and rapid growth of offspring (Deacon et al 2015). By the time calves are several months of age they are already browsing and ruminating and by six months old are feeding with the other females and their offspring. Bodysize increases quickly and they double this within the first 12 months. Young are weaned between 9-12 months old but typically stay with their mothers for another six months, after which juvenile males may leave to join bachelor groups. Young females usually remain in the herd or join another group in the same area (Skinner and Hall 1975; Furstenburg 2013; Schorrocks 2016). Offspring survival is highest during the dry season4 but in general, Giraffe mortality is high in the wild for their first few years of life. Estimates are that less than half of calves reach 12 months old; however, nearly all young (>98%) survive after their second year. The reason for such a high mortality rate is uncertain with factors such as disease, nutritional stress and predation likely to play a role (Deacon et al 2015). Primary predators upon Giraffe of all ages are lions (Panthera leo); but include other carnivores such as leopards, African wild dogs and crocodiles (Toon & Toon 2004). Adults are also targeted by human hunters. Other causes of fatality in the species’ include disease, nutritional stress and are prone to heart attacks (Bertelsen 2015; Schorrocks 2016; Dunn et al 2020). Average longevity for Giraffe is relatively short at only around 15 years, but both sexes can reach 25 years or beyond (Schorrocks 2016). Data from zoo populations indicates around half of males die before the age of 10, and half of females do not reach 12 years old (EAZA 2006), but some individuals attain a much longer lifespan of
5.0 Habitat Requirements and Preferences
Giraffe habitat is characterised by the presence of their main food vegetation communities and
various woodland trees, typically within dry savannah areas of woodland, scrubland and open
grassland. In some regions these browsing animals can be found in semi-desert and desert habitat
e.g. Namibia, and less often in mesic forests and riverine areas. Giraffe avoid closed forests and
are absent from mountains and rainforests (Furstenburg 2013; Muller et al 2016; O’Conner et al
2019; SDZWA 2021).
A plentiful supply of food trees and shrubs are critical to sustain energy requirements of this
megaherbivore. Higher rainfall leads to greater plant productivity; therefore also influences Giraffe
home range size on a spatial and temporal scale throughout their distribution (Knüsel et al 2019).
Herds are often associated with tall vegetation, which may play a secondary role in camouflage
against predators (Schorrocks 2016); but females with young show a distinct preference for more
open habitats, perhaps because such landscapes improve visual detection of approaching predators
(reviewed in Fennessy et al 2020).
Sub-Saharan Africa is a vast area containing an array of landforms with localised variables resulting
in different climate zones (Eriksen et al. 2008), but the region is characterised by high annual
temperatures, and greater extremes from day to night than on an annual basis (Section 11). Giraffe
are especially adapted to this hot climate and able to withstand remarkable levels of heat and
radiation; although how they do so remains uncertain. They have non-functional sweat glands and
will seek shade in high ambient temperatures (34 - 37°C) but do not utilise water for cooling. It
has been proposed that a large frontal sinus space within their skull may assist evaporative heat
loss, but there is no evidence for this role. Current consensus is that Giraffe avoid overheating
through a combination of their unique body shape and unusual thermoregulation characteristics
(Schorrocks 2016; Mitchell et al 2017). Body temperature fluctuates with ambient temperature,
rising throughout the day and then cooling during the night. Normal body temperature is in the
range of 37.5 - 38.8°C but drops as low as 36.7°C in cold conditions and rises as high as 40°C on
hot days (Schorrocks 2016).
Adaptations to high levels of heat and radiation in an arid environment make Giraffe particularly
vulnerable to cold exposure. Although low environmental temperatures occur overnight within the
species’ natural habitat, these declines are brief and cool temperatures do not persist; this means
animals are able to balance energy reserves and requirements and guard against hypothermia
(Furstenburg 2013; Bertelsen 2015; Schorrocks 2016) (Section 8). In the wild, a high number of
Giraffe deaths are associated with sudden or prolonged cold or wet events; and acute mortality
syndrome (linked to hypothermia), is a well-documented cause of mortality in captivity (Clauss et
al 1999; AZA 2014; Bertelsen 2015).
Page 10 of 266.0 Natural Geographic Range
Giraffe are endemic to Africa and roamed throughout the entire continent until around 10,000 years
ago. They gradually became restricted to the sub-Saharan area after northern Africa became a
desert, with populations going extinct in the far east of Egypt 4000 years ago followed by
disappearance of the species in Morocco 1400 years BP. Figure 3a overlays a map of historic
distribution since the 18th Century with present occurrence and highlights the large scale
fragmentation of remnant populations. This herbivore is predominantly found within grassland
biomes (Section 6, above) (Figure 3b) and restrictions to natural movement within the landscape
include features such as rivers5 as well as barriers associated with human activity and settlements
e.g. fencing and border protection (Furstenburg 2013; Muller et al 2016; Schorrocks 2016).
The current distribution range combined for all Giraffe populations is reported by IUCN as around
1.8 million square kilometres (1,818,180km2 Muller et al 2016). This figure was recently revised
at 1,717,047 square kilometres based on a multidisciplinary approach of contemporary mapping
and review (O’Connor et al 2019).
Figure 3: a) past and present distribution of Giraffe (Giraffa sp.) including new data on the species’ geographic range
(O’Connor et al 2019); b) map of current biomes for the region https://www.slideshare.net/rluppo1982/africa-
geography-16659306.
Giraffe are still present in over 20 countries throughout their endemic range (Figure 4, over page),
but went extinct in seven countries in the last century alone. Habitat loss is cited as the common
causal factor of range reduction (Section 3, Conservation), driven by human land use activities such
5
Giraffe avoid entering water and are not known to swim (Schorrocks 2016)
Page 11 of 26as agriculture and infrastructure development which are predicted to continue to accelerate in line
with high human population growth in the region (Schorrocks 2016; Muller et al 2018; O’Connell
et al 2019). Range reduction is a particular cause for concern for populations in highly isolated
locations such as Masai Giraffe (G.(c). tippelskirchi) in East Africa where populations are
documented to have undergone a dramatic decline of around 50% over the last 30 years, making
them clear priority for conservation management.
Figure 4: Giraffe current distribution
demonstrating range countries. Dashed outline
indicates recognised IUCN range for each taxon
with cross‐hatched areas (from O’Connell et al
2019).
7.0 Introduced Geographic Range
No feral Giraffe populations are reported. Translocations are routinely practiced as part of
conservation management and include introduction and reintroduction within their known sub-
Saharan distribution. Giraffe have an extensive captive history, being held within private
collections, safari parks and zoos around the world for centuries; however, there have been no
escapes resulting in free living animals occurring outside this species’ natural range.
Page 12 of 268.0 Potential Distribution in Tasmania
CLIMATCH software v2 (Nov 2020; ABARES, Department of Agriculture, Water and the
Environment) was applied to map the historic and present known distribution of Giraffe, resulting
in a total assessment area of around 16,700,000 km2 (Figure 5). This source data was used to predict
potential range for the species within Australia (target area), comparing long-term rainfall and
temperature patterns between the two areas. Results of the analysis indicated environmental
conditions would be least favourable for the species in the cool temperate climate of Tasmania
(Figure 6), but CLIMATCH modelling is unlikely to accurately reflect suitable habitat for Giraffe
in the state, because of major limitations incurred by their unique biology and habits.
Figure 5: CLIMATCH plot of global distribution of Giraffe, G. camelopardalis, with red dots (weather stations)
indicating the species’ known historic and present range https://climatch.cp1.agriculture.gov.au/climatch.jsp
Figure 6. CLIMATCH modelling output of potential range for Giraffa sp. in Australia, and Tasmania (inset); colour
coding indicates match score from most (10) to least (0) climatic suitability
https://climatch.cp1.agriculture.gov.au/climatch.jsp
Page 13 of 26Giraffe are tropical megaherbivores. These specialised browsers require a massive dietary intake to meet their daily energy needs (Section 10, Diet and Feeding Behaviour) and are extremely vulnerable to cold, sustained low temperatures and damp conditions even within their natural environment (detailed in Section 6). The adaptations that enables them to survive extremely hot conditions would confer serious disadvantages for survival in a cool, temperate climate such as Tasmania. In terms of the species’ nutrition, Giraffe feed predominantly on woody plant parts and forbs and they show a distinct preference for native Acacia species (Kearney 2005; Schorrocks 2016). In Australia, this Genus represents the second most common forest type, and grows in arid areas6 where rainfall is
temporarily during translocation events (Fennessy et al 2020). The species’ lower tolerance
threshold is commonly cited as 10ºC, and indoors areas are recommended to be kept above 18ºC
(Clauss et al 1999; EAZA 2006; AZA 2014). Furstenburg (2013) notes Giraffe may counter low
overnight temperatures by moving upslope away from cold plains and waterways, but they seem to
lack sheltering behaviours; and in wild populations mass deaths are reported after cold, damp
weather events (Clauss et al 1999).
9.0 Diet and Feeding Behaviour
Giraffe are most active during daytime hours but also move, browse and ruminate throughout the
night, with peaks in feeding occurring in both morning and evening. Unlike smaller bodied
browsing ungulates, a large body size means they cannot be overly selective of feed plants due to
the volume required to maintain their energy needs, which is considerable at up to 2% of their
bodyweight, and need to feed for up to 16 hours per day. They feed on around 65 different plant
species - predominantly woody plants and forbs, and availabilities vary by location and season with
forage quality and quantity linked to spatial use of habitat and population dynamics including male
migration (Brown & Bolger 2020). Giraffe feeding activites are considered to play a key role in
ecosystem function, helping stimulate plant growth, pollination, and seed dispersal (O’Conner et al
2019).
Plant parts eaten are primarily leaves and stems, but also include fruits, flowers, bark, thorns, and
pods. Giraffe rarely feed on grasses and may only ingest them by accident when feeding on other
plants. The most common food plants selected are those of the Acacia Genus - particularly A.
vacheillia and A. senegalia which grow throughout Giraffes’ natural range. Acacia contains high
protein, water, and calcium7 content necessary to meet their specific nutritional needs; however,
because these plants are deciduous, in the dry season they shift to other plants e.g. Faidherbia,
Boscia, Grewia, and Kigelia spp. Other important food plants are Combretum, Balanites,
Commiphora, Detarium, Terminalia and Ziziphus spp. (Kearney 2005; Muller et al 2016; Fennessy
et al 2020).
Giraffe typically browse at height, on vegetation well above the reach of most other herbivores.
Males tend to browse at greater heights than females independent of their elevated reach. Feeding
in this manner results in a distinctive pruned strip in trees, around 4.5 - 5.5m from the ground.
Animals are able to tip their head back nearly vertically (as illustrated in Figure 2) and they use
their prehensile tongue to strip plant material off against their hard upper dental pad. Adaptations
to feeding on Acacia include a thick mucus layer and dense papillae on the tongue to protect the
mouth from thorns and the stomach specialised to withstand fatty acids and alkaloids present in
these plants. In typical ruminant manner, they swallow food with minimal chewing and partially
digested matter is regurgitated later as cud for rechewing. Giraffe are the only species that does
not rest while ruminating, probably born of necessity because of the continuous browsing necessary
to support their daily requirements (Schorrocks 2016).
Occasionally, Giraffe are observed eating soil, licking salt or chewing on bones. This behaviour is
associated with nutrient poor environments and attributed to the species’ high needs for calcium
and phosphorus7 (Schorrocks 2016; Fennessy et al 2020).
7
These minerals are thought to be necessary to support skeletal growth in this large species
Page 15 of 26Like many savannah animals, they rely on their food for the majority of their water intake. Giraffe
may supplement this by drinking from rivers or streams every few days (Furstenburg 2013;
Schorrocks 2016) but populations in some areas are completely water independent, obtaining all
needs from vegetation (Fennessy et al 2020). Giraffe are especially vulnerable to predators when
drinking because for their head to reach the ground they must splay their forelegs wide or kneel
(Figure 2). Drinking is an activity usually preceded with increased vigilant behaviour, and animals
often choose to drink at night to avoid predators and prevent interference from other species (Seeber
et al 2012; Schorrocks 2016).
10.0 Social Behaviour and Groupings
Giraffe social structure is still not well understood, despite numerous studies conducted over the
last few decades. Animals live in loose herds made up of a combination of age classes and sexes
and both group composition and size are fluid. They are still complex networks, and often termed
“fission-fusion” because individuals of both sexes move between groups. Associations seem to be
based on a range of factors from ages and sexes to individuals’ relatedness and familiarity. Bonding
is typically short term, but some animals may form longer associations with indications that this
may benefit lifetime fitness e.g. female groups (VanderWaal et al. 2014; Schorrocks 2016, Fennessy
et al 2020; Bond et al 2021).
Home range sizes are influenced by food and water availability, environmental variables such as
rainfall and temperature, and also the presence of conspecifics, other herbivores and predators
(Schorrocks 2016). Range sizes vary between individuals and sexes but females tend to have
smaller home ranges and are philopatric. Sexes and age classes share overlapping ranges and they
do not exhibit territorial behaviours. Published information on individual animals’ movements vary
widely (>10km2 to over 10,000km2), but ~100 km2 is considered an average range size (Fennessy
et al 2020).
Giraffe group size is influenced by season and resources, but herd size is typically small and usually
contain less than 10 animals. Mixed sex herds are significantly larger on average, with some groups
exceeding 100 individuals. Herd size and behaviour may be influenced by the presence of predators
but the effect of increased vigilance on size or composition of groups is uncertain (Cameron & du
Toit 2005; Schorrocks 2016).
Vision is most likely the primary cue based on this ungulate’s excellent eyesight, time animals
spend watching other group members, scanning and vigilant (Seeber et al 2012; Schorrocks 2016;
Kasozi & Montgomery 2018). Like most ungulates, Giraffe have high resolution vision but it is
thought that they also have exceptional long range distance and acuity. There is evidence they can
detect movement at a distance of two kilometres which may be important to allow individuals
within a group to maintain visual contact over considerable distances (Kasozi & Montgomery
2016).
There is no strong evidence of a hierarchy8, matriarch type arrangement or harem structure within
groups. Tactile social contact between herd members is not common, but animals will intentionally
bump bodies, rub their head and neck on each other, allogroom and nuzzle (Seeber et al 2012).
Males spar using their neck and ossicones during play or actual fights. Dominant posturing
8
Dominant males will displace subordinates for access to receptive females (Seeber et al 2012).
Page 16 of 26involves standing erect and lateral presentation with the head / neck held high, arched or parallel to
the ground. During fighting (termed “necking”) males stabilise themselves by spreading their legs
and leaning against each other with their headquarters, and then swing the head and neck toward
their opponent with substantial force. The ossicones are used to club each other and may break
completely off during sparring, but do not regrow. Males are capable of injuring and killing each
other; however, serious fights are rare (Seeber et al 2012; Furstenburg 2013; Schorrocks 2016;
Fennesy et al 2019).
Giraffe emit a limited repertoire of audible sounds (e.g. grunt, snort, hiss, bleat, bellow, hum9) but
usually only vocalise when distressed (Bercovitch & Deacon 2015; Kasozi & Montgomery 2018;
Volodina et al 2018). It is thought they may be capable of communicating using low frequency
infrasound, as documented for their close relative the Okapi and for African elephants; but this
ability is as yet unproven (Bercovitch and Deacon 2015; Schorrocks 2016; Fennessy et al 2020).
Okapi also scent mark using paste produced by specialised hoof glands, but these structures are not
present in Giraffe. Olfactory communication in this species seems to be limited to males’ sexual
investigation of females (Section 4), and bonding between the cow and her calf (Seeback et al 2012).
11.0 Natural Predators and Disease
11.1 Predators
Natural predators are large African carnivores such as lion, leopard (Panthera pardus), hyaena
(Crocuta crocuta), and Painted dog (Lycaon pictus), but crocodiles are also known to attack and
kill giraffe. Lions are considered to be the main predator of all age classes. Calves are particularly
vulnerable, and cows actively defend them by stomping upon attackers with the front legs or kicking
them with their hindlegs. Giraffe grow rapidly and by the time they are subadults they are capable
of escape or self-defence. Their body size enables them to able to seriously injure or kill potential
predators by stomping or kicking and males may defend themselves by butting with the neck, head
and use of horns (Schorrocks 2016; Fennesy et al 2019; GCF 2021). Wild Giraffe have been hunted
by humans for centuries, and this practice persists today (Section 4, Conservation).
In Tasmania there are no native or introduced carnivores large enough to present a threat to free-
roaming Giraffe. A possible exception would be young calves which could be vulnerable to attack
from domestic dogs, Canis familiaris.
11.2 Disease
Giraffe do not have any specific disorders but are susceptible to diseases seen in other wild
ungulates and domestic stock such as viruses (rabies Lyssavirus, Crimean-Congo haemorrhagic
fever Bunyaviridae), protozoans, bacteria (Leptospirosis, Johne’s Disease, Anthrax, Brucellosis)
fungal and parasitic infections such as hydatids (Magwedere et al 2012; Bertelsen 2015; Junker et
al 2015; Schorrocks 2016; Hlokwe et al 2019; Fennesy et al 2019; Aruho et al 2021; Hernkova et
al 2021). Spread of Rinderpest (Paramyxoviridae) from infected cattle to African wildlife in the
late 19th Century is thought to have played a role in reduction in the Giraffe’s former range, and this
epidemic continued to spread through the continent until the 1960s (Furstenburg 2013; Schorrocks
2016).
9
Humming has only been recorded at night in captivity and the purpose is unclear
Page 17 of 2612.0 Threats to Human Safety
12.1 Injury
Giraffe are usually non-aggressive, with even wild individuals described as “readily approachable
and tractable” (Fennessy et al 2020); this undoubtably has contributed to the ease at which they are
hunted by humans. As a large-bodied animal they are capable of inflicting serious injury or death
by kicking, stamping upon or striking a person with their head and neck region. In a confined
setting, unintentional harm can be caused by flailing legs or hooves of flighty individuals (EAZA
2006; Bertelsen 2015; Fennesy et al 2020), but attacks on people by Giraffes are rare in either the
wild or captivity. Such events have been associated with situations where animals were provoked,
cornered, or protecting offspringi.
12.2 Disease
Zoonotic diseases are predominantly driven by conversion of wildlife habitats to farming and
settlements, as well as increased contact between humans, native fauna and domestic animals. Well
prior to the current SARS-CoV-2 pandemic, the game meat and tourism sector in Africa was
highlighted as serious cause for concern (Magwedere et al 2012). Impact from zoonoses affecting
Giraffe is low but considered deserving of increased surveillance and monitoring in light of
frequency of translocations and the expansion of game farming and trade in the Sub-Saharan region
(Schorrock 2016; Muller et al 2020; Dunn et al 2021).
Herbivores serve as intermediate hosts for Toxoplasma gondii. Studies of free-ranging and captive
populations suggest that similar to cattle, Giraffe are relatively resistant (Junker et al 2015). This
parasite is common and distributed throughout the world. It is spread between intermediate and
definitive hosts (in Australia the former includes mammalian livestock and natives e.g. macropods,
wombats and dasyurids: WHA 2017), but requires felids as definitive hosts to complete its’ life
cycle. In Tasmania, feral cat populations and Toxoplasmosis occur throughout the state (Fancourt
& Jackson 2014); therefore, no additional threat would be incurred.
Most diseases reported for Giraffe are already reported in domestic animals, livestock, and wildlife
in Australia. Rabies, anthrax, rinderpest, and bovine tuberculosis reported in wild Giraffe are List
A notifiable exotic diseases under the Animal Health Act (1995), and not present in Tasmania. As
part of standard process for importation of wildlife to the state, animal/s being transferred in must
undergo veterinary examination and medical treatment and remain subject to routine control of
parasites and health reporting under DPIPWE’s wildlife exhibitor licence conditions. For
international imports, the premise and animal/s must also be certified to be free from disease by an
Official Veterinarian and undergo quarantine and testing prior to and after arrival in Australia.
Giraffe imports to Tasmania are not considered to represent any disease risk to humans.
Page 18 of 2613.0 History as a Pest
There are no established Giraffe populations in the wild outside of their natural distribution (Section
8, Introduced Geographic Range), and they are not listed as a pest. The species has a long history
of coexistence with humans including herders but are specialised browsers and do not compete with
livestock for food. Continued conversion of their natural habitat for agriculture and expansion of
cultivated areas coupled with drought conditions have led to some perceived problems. Conflict
between native herbivores and farmers in Africa predominantly involve elephant incursions to
human land use areas. There has been some growing negativity reported toward Giraffe because
of interference (trampling and feeding on crops) but people retain a fairly tolerant view toward
them, probably because these animals are not considered dangerous (LeRoy et al 2009).
A study of farms in Namibia found Giraffe play a minor role in damage (3.8%) or raiding (6.5%)
of cultivated fields, especially by comparison with other ungulates (e.g. elephant 30%;
warthog/wild pig 30%; zebra 14%). Crops targeted tend to be those with high protein content such
as maize (Zea mays), hyacinth beans (Lablab purpureus) and cowpeas (Vigna unguiculata) (Pitiglio
2009), but Giraffe occasionally enter villages to feed at granaries and on fruits from mango trees
(Mangifera indica) (LeRoy et al 2009).
Use of effective fencing is proven to be a reliable physical barrier to Giraffe. These animals are not
known to jump, but the length of their legs enables them to walk over fences up to 1.5m in height
(Furstenburg 2013). Taller fences are not usually breached (Le Roy et al 2009), but they may try
to clamber through them, lifting front legs over and dragging their hind legs behind which can result
in serious damage to the structure and the animal (Furstenburg 2013; Fennessy et al 2020).
14.0 Potential Impact in Tasmania
Giraffe are specialised browsers adapted to a hot tropical climate with a life history pattern
characterised by a slow rate of reproduction. They are long lived but have late onset to sexual
maturity and cannot reproduce each year because of an extensive period of gestation (Section 5,
Life History). Successful establishment of an introduced species in the wild requires populations
to become self-sustaining; meaning that free-ranging individuals need to locate and utilise key
resources to survive and reproduce. This includes access to suitable conditions, nutrition, viable
mates and appropriate conditions to rear offspring.
Within Tasmania, there would be negligible potential impact from free ranging Giraffe upon
environmental assets, primary industries, or through damage to property or infrastructure. This
species is unlikely to represent a nuisance or threat to people. As specialised browsers, they are
unlikely to have any impact on agricultural, amenity plants or vegetation communities and are not
envisaged to compete with native or introduced herbivores or other animals.
In consideration of the Giraffe’s gigantic size, their potential impact in the wild is a rather moot
issue because any escaped individuals would be readily detected and recaptured or removed. The
species’ extreme vulnerability to cold conditions means that even in the short-term, animals are
likely to perish from exposure in Tasmania’s cool temperate climate. The state is characterised by
mountains, rivers, dense bushland and farmlands which would highly restrict movement of Giraffe
through the landscape.
Page 19 of 2615.0 Previous Risk Assessments
With the proviso that there is no endorsed risk assessment for Giraffe in Australia, the Environment
and Invasives Committee state that they categorised them using a precautionary approach, listing
G. camelopardalis as an extreme threat by default (EIC 2018).
16.0 Risk Management
This Species Profile is provided to DPIPWE as supporting information for an application to import
Giraffe (G. camelopardalis) into Tasmania. Under the Department’s Policy on Importing (and
Keeping) Vertebrate Wildlife in Tasmania (July 2017), a Risk Assessment will be formally
conducted by their Natural and Cultural Heritage branch (NCH) following the Risk Assessment
Methodology for Importing Vertebrate Wildlife in Tasmania (DPIPWE 2017). This includes use
of the Bomford (2008) Modelling System to predict likelihood and impact of species establishment
in the wild.
The outcome of the Risk Assessment is that the species proposed for import is assigned to a threat
category (Low, Medium, Serious or Extreme). If import is to be permitted additional conditions
may be imposed - for example, limiting higher risk species to licence holders approved for keeping
serious threat species, or restricting import to a single sex or individuals that are unable to
reproduce. Under DPIPWE’s wildlife import policy, after a species is approved, importers must
meet additional requirements to mitigate risk of escape or establishment in the wild.
Requirements for approved importers include providing health certification and proof of permanent
identification (e.g. microchipping) of animals prior to their import, and submission of a Species
Management Plan for approval. The latter document must include details such as site security,
animal holdings, health and husbandry practices, standard operating procedures, and staff
experience. DPIPWE representatives also usually conduct an inspection of the site and enclosures
prior to issuing an import permit. The licenced facility is responsible for record keeping and routine
reporting to the Department and remains subject to audit at short notice.
In the decision-making process, identified risks will be weighed against the purpose and benefits of
the species being imported to the state such as research, education, support of conservation and
enterprise etc.
Page 20 of 26You can also read
