Content uploaded by Victoria Inman
Author content
All content in this area was uploaded by Victoria Inman on May 29, 2019
Content may be subject to copyright.
Afr J Ecol. 2019;00:1–3. wileyonlinelibrary.com/journal/aje
|
1
© 2019 John Wiley & Sons Ltd
Received:2November2018
|
Revised:5M ay2019
|
Accepted:8May2019
DOI : 10.1111/aje.1264 4
NOTE AND RECORD
Observations on the response of a pod of hippos to a dead
juvenile hippo (Hippopotamus amphibius, Linnaeus 1758)
Victoria L. Inman1 | Keith E. A. Leggett1,2
1CentreforEcosystemScience,SchoolofBiol ogical,Ear thandEnv ironme ntalSciences ,UNSWSydn ey,Sydney,NewSout hWales,Australia
2FowlersG apAridZoneRese archStation,SchoolofBiological,Ea rthan dEnvironmentalSciences,UNS WSydney,Sydney,NewSouthWales,Aust ralia
Correspondence
VictoriaL.Inman,CentreforEcosystemScien ce,Scho olofBiol ogical,Ear thandEnvironme ntalSciences ,UNSWSydney,Sydney,NSW2052,Au stralia.
Email:victoria.inman@outlook.com
1 | INTRODUCTION
Hipposaregregariousanimals,generallyoccurringaspodscompris-
ingfemalesandtheiryoung,adominantmaleandsubordinatemales
(Klingel,2013).The moststablerelationship in a podis between a
mother andher young(Klingel,2013). Withinapod, thedominant
malehasexclusivematingright sand hasbeenknowntocommitin-
fanticide,whichisthoughttoreducetheinterbirthingintervalofthe
female(Lewison,1998).Giventheirsizeandaggressivenature,adult
hippos have f ew natural pre dators; however, the sm aller juvenil es
aremorevulnerable(Klingel,2013).
Thereislittlepublishedliteratureonthebehaviourofhipposfol-
lowingthedeathofaconspecific.Theavailableliteraturefocuseson
rare occurrences of hippos consumingthe meat of a hippocarcass
(D orwa rd, 2015) .Re co r ds ofm amm als inter a c tin gwi thd ead con spe -
cificsinanepimeleticmanner(maintainingphysicalcontact,moving/
carrying,andprotectingcarcasses)areincreasing(e.g.Bearzi,Eddy,
Piwetz,Reg gente,&Cozzi,2017;Reggenteetal.,2016).Speciesdis-
playingthesebehavioursincludegiraffes(Bercovitch,2013;Strauss
&Muller,2013),elephant s(Douglas‐Hamilton,Bhalla,Wittemyer,&
Vollrath, 2006),nonhumanprimates (Cronin,Leeuwen,Mulenga,&
Bodame r,2011; Fashing et a l., 2011; Yang, Anders on, & Li, 2016),
andcetaceans (closerelativestohippos, Reggenteetal.,2016),and
reportscommonlyrelatetoafemaleinteractingwiththecarcassof
ajuvenile. There are photographs/videos showinghipposinteract-
ing with hi ppo carcas ses (Breen , 2010; Harris, 2014; Hipp o keeps
crocsfromdeadjuvenile,2008;Hippopotamus(Hippopotamusam-
phibius),2006;ViralHog,2016)anddefendingcarcassesfromother
animals (C saba, 2017; Harris, 2014; Hip po keeps crocs f rom dead
juvenile,20 08); providing anecdotal evidencethat hipposmayalso
displayepimeleticbehaviourtowardsdeadconspecifics.
This note do cuments det ailed obse rvations of a n adult female
hippoandpodinteractingwithadeadjuvenile(<6monthsold)hippo
withintheiraquatichabitatoverthecourseof11hr.
2 | METHODS
As part of a project investigating hippo behaviour, the observer
(Victoria Inman) regularly conducts fullday observations on hippo
pods.Theobservationsreportedhereoccurredfrom06:45to17:30
on 14 Septembe r 2018 at a hippo pool (17.82823°S, 25.02 928°E,
0.5 ha) in Chobe National Park, nor thern Botswana. The observa-
tionsweremadefromavehicleparkedapproximately50mfromthe
edgeofthepool,with the hipposbetween 50 and 160mfromthe
observerduringtheobservationperiod.Thebehaviour,movements
and time of in teractions were r ecorded as they occu rred; oppor-
tunisticimagesandvideoswerealsotaken.Binoculars(8×42,FOV
426ft)wereusedtoobser vethehipposwherenecessary.
3 | RESULTS AND DISCUSSION
The pool where the observations occurred was known to support
apod of 24–26hippos (4 and 7 September2018).At 6:45 a.m. on
14September2018,itwas observed that therewas only one adult
femaleinthepoolandajuvenilehippocarcass,forwhichthecause
ofdeath was unknown.Weconsider it likely that theadult female
wasthe mother of the deadjuvenile,asit was the only hippo that
hadremainedwiththecarcass.Additionally,shewasanadultfemale
andhadenlargedmammar yglandsconsistentwithalactatingfemale
(Laws&Clough,1966).Othermembersofthepodwereinthemain
channelapproximately110metresawayfromthepool.
From 6:45 to 12:30, t he female alterna ted between movi ng
aroundthepool,interactingwiththecarcass,attackingandchas-
ingcrocodilesfeedingonthecarc assandforshor tperiodsoftime
restingin the water.The interactionsinvolvedthehippo pushing
the carc ass around t he water with h er muzzle (F igure 1.), lif ting
thecarcassoutofthewaterwithherhead,andt akingthecarc ass
inhermouthandmovingaroundthepool,divingandsubmerging
2
|
INMAN ANd LEGGE TT
(Figure 2; V ideoS1). Several ti mes the femal e shook the ca rcass
quite forcefully.Twice, the female cameto theedge ofthe pool,
partiallymovedontolandanddisplayedaggressionbyyawningat
the vehicle. This behaviour was unexpected as these hippos are
habituated to vehicles. The aggressive behaviour of the hippo
towards th e crocodiles ( VideoS2) i s also uncommo n; hippos and
crocodiles generally share this pool without conflict (personal
observation).Further evidenceof uncommon behaviourwas the
amountofsmallbubblesthehippocreatedasitmovedunderwa-
ter. The majority of hippo communication occurs amphibiously
(Barklow, 2004), and some sounds produce bubble streams
(Maust‐mohl, Soltis,&Reiss,2018). Throughout the morning,the
adult female vocalised three times, which garnered a response
fromhipposinthemainchannel.
Ataround12:30,sevenhippos(2adultmales, 2adultfemales1
subadultand 2 juveniles)moved as a groupon land from the main
channel to t he pool where t he original fem ale was. Norma lly,t he
hipposmovefromthemainchanneltothepoolearlyinthemorning;
however, on this day th ey appeared to h ave delayed their ar rival.
Whilst t he original female c ontinued to intera ct with the carc ass
(Figure3;VideoS3),asfarastheobser vercouldtelltheotherhippos
didnot.
From12:30 to 13:30, the original female continued interacting
with the c arcass, eve ntually pu shing it to a shall ow sectio n of the
pool,sothatthecarcasswashalfsubmerged.Immediatelyafterthis,
ataround13:30,allthehippos,includingtheoriginalfemale,moved
asa grouprapidlybacktowards the main channel (stoppingonthe
sandbankadjacenttothechannel).
Between13:30and 14:30, the group ofhippos slowlyandindi-
viduallyorinpairs walkedback to thepool. Five additionalhippos
joined,makingatotalofthirteenhipposinthepool.Thismovement
backandforthbetweenthetwoareaswasuncommonandpossibly
duetothepresenceofthecarcass.
For the rema inder of the obser vation period (14:45–17:30), all
thirteen hippos stayed in the pool. Initially, the other hippos had
limited interaction with the carcass, butthis gradually increased as
thedayprogressed.This rangedfromtouching thecarcass,pushing
itaround the pool,andtaking the carcass intheir mouthsandmov-
ingwith it. At thistime, it was impossible to distinguish theoriginal
observedadult femalefromthe later arrivals and thisindividualbe-
haviourwaslost.
Cannibalism in hipposhasbeen recorded(Dorward, 2015) and,
whilst therewere numerous times when different hipposhad the
carcas s in their mouth s, it was unclear i f any consumption of t he
FIGURE 1 Photographofadultfemalehippopushingjuvenile
carcassthroughwaterwithhermuzzle
FIGURE 2 Photographofadultfemalehippomovingwith
juvenilecarcassinhermouth
FIGURE 3 Photographofadultfemalehippopushingjuvenile
carcasstothesurfaceofthewaterwithherbody.Noteadultmale
inbackground
|
3
INMAN AN d LEGGET T
carcass occurred. Invideos of hippos consuming meat, the hippos
movetheir mouthupanddownonthemeat inat ypical“chewing”
motionandlifttheirheaduptoswallow.Thisheadbackswallowing
motionhasbeenseennumeroustimesbytheobserverwhenhippos
eat aquat ic vegetation. N o hippo on this day w as observed to b e
doingthisaction; however,thepossibilit yof cannibalism cannotbe
disregarded.Uponconclusionoftheobservationperiod,thecarcass
wass ig nif ica ntl yd ama ge d ,w hic hc anp ro bab lyb ea t tr ibu ted to cr oc-
odilescavenging.
Thispaperprovidessupportforanothermammalspeciesexhib-
iting apparent epimeletic b ehaviours towards a dead consp ecific.
Theinteractionsthatoccurred,particularlytheadultfemaledefend-
ingthecarcass fromcrocodiles,lif ting the carcassoutofthewater
andmovingthecarcasstoashallowsectionofwaterbeforeleaving
it, are con sistent with other o bservation s in highly social ani mals
(King,2013).
ACKNOWLEDGEMENTS
We thank Elephants Without Borders for hosting this study and
theBotswanaMinistryofEnvironment,WildlifeandTourismforaf-
fordingusthe opportunitytoconductthisresearch.TheUniversity
ofNewSouth Walesand the AustralianGovernment are acknowl-
edgedfortheirsupportoftheproject.
DATA ACC ESSIB ILITY
Thedata(originalfieldnotes)thatsupportthefindingsofthisstudy
areavailablefromthecorrespondingauthoruponrequest.
ORCID
Victoria L. Inman https://orcid.org/0000‐0002‐5646‐7908
REFERENCES
Barklow,W.E.(2004).Amphibiouscommunicationwithsoundinhippos,
Hippopotamus amphibius. Animal Behaviour,68, 1125–1132.https://
doi.org/10.1016/j.anbehav.2003.10.034
Bearzi, G., Edd y, L., Piwet z, S., Reggente, M . A., & Cozzi, B. (2017).
Cetacean behavior toward t he dead and dying. Encyclopedia of
Animal Cognition and Behavior,1–30.
Bercovitch, F.B. (2013). Giraffecowreactiontothe death of hernew-
born calf. African Journal of Ecology, 51(2), 376–379. https://doi.
org /10.1111/aj e.12016
Breen,R. (2010).May 9.Hippo canabilism?(Okavango Delta, Botswana)
[Blogpost].Retrievedfromhttp://roarafrica.blogspot.com/2010/05/
hippo‐canabilism‐okavango‐delta.html
Cronin,K.A.,VanLeeuwen,E.J.,Mulenga,I.C.,&Bodamer,M.D.(2011).
Behavio ral respon se of a chimpanze e mother towar d her dead in-
fant. American Journal of Primatology, 73(5), 415–421. https://doi.
org/10.1002/ajp.20927
Csaba,X.(2017). September21.Hippo protects carcass from hungry hye-
nas [Video File].Retrieved from https://www.newsflare.com/video/
152993/animals/hippo‐protects‐carcass‐from‐hungry‐hyenas
Dorward,L .J. (2015). Newrecordofcannibalismin thecommon hippo,
Hippopotamus amphibius(Linnaeus,1758).African Journal of Ecolog y,
53,385–387.
Douglas‐Hamilton, I., Bhalla, S., Wittemyer, G., & Vollrath, F. (2006).
Behavio ural reac tions of eleph ants towards a d ying and dece ased
matriarch.Applied Animal Behaviour Science,100(1–2),87–102.https
://doi.org/10.1016/j.applanim.2006.04.014
Fashing, P. J., Nguyen, N., Barry, T. S., Goodale, C . B., Bur ke, R. J.,
Jones, S. C. Z., …Venkataraman, V.V.(2011).Death amonggeladas
(Theropithecus gelada):Abroader perspectiveon mummified infant s
andprimatethanatology.American Journal of Primatology,73(5),405–
409.https://doi.org/10.1002/ajp.20902
Harris,S.A.(2014).April7.Heartbreaking moment a mother hippo realises
her baby is dead. Express. Retrievedfrom https://www.express.co.
uk/news/nature/469120/Heartbreaking‐moment‐a‐mother‐hippo‐
realises‐her‐baby‐is‐dead
Hippo keeps crocs from dead juvenile(2008).Retrievedfromhttp://www.
wildlife‐pictures‐online.com/hipposighting.html
Hippopotamus (Hippopotamus amphibius).(2 006). Retrieve d from https
://www.arkive.org/hippopotamus/hippopotamus‐amphibius/im-
age‐G20273.html
King, B . (2013). When anim als mourn. Scientific American, 309,62–67.
https://doi.org/10.1038/scientificamerican0713‐62
Klingel, H. (2013). Hippopotamus amphibius common hippopotamus.
In J. Kingd on, & M. Hoff man (Eds.), Mammals of Africa: Volume VI:
Pigs, hippopotamuses, chevrotain, giraffes, deer and bovids(pp.68–77).
London,UK:BloomsburyPublishing.
Laws, R . M., & Clough, G.(1966).Observations on reproduction in the
hippopotamusHippopotamus amphibiusLinn.Comparative Biology of
Reproduction in Mammals,15,117–140.
Lewison,R.(1998).Infanticideinthehippopotamus:Evidenceforpolyg-
ynousungulates.Ethology Ecology & Evolution,10,277–286.https://
doi.org/10.10 80/0 8927014.1998 .9522857
Maust‐mohl,M.,Soltis,J.,&Reiss,D.(2018).Underwaterclicktrainpro-
duction by the hippopotamus (Hippopotamus amphibius) suggests
an echo‐r anging f unction. Behaviour, 155, 231–251. https://doi.
org/10.1163/1568539X‐00003484
Reggente , M., Alves, F., Nicol au, C., Freit as, L., Ca gnazzi, D., Ba ird, R.
W.,& Galli,P.(2016).Nur turantbehavior towarddead conspecific s
infree‐ranging mammals: Newrecordsfor odontocetes andagen-
eral review. Journal of Mammalogy, 97(5), 1428–1434. https://doi.
org/10.1093/jmammal/gyw089
Strauss ,M.K.,&Muller,Z.(2013).Giraf femothersinEastfricalingerfor
daysneartheremainsoftheirde adcalves.African Journal of Ecolog y,
51(3),506–509.
Viral Hog (2016) Januar y 13. Strange Hippo Behavior Part 1 [Video File].
R e t r i e v e d f r o m h t t p s : / / w w w . y o u t u b e . c o m / w a t c h ? v = U ‐ y v p 8 H q 1 e A
Yang, B., Anderson, J. R., & Li, B. G. (2016). Tending a dyingadult ina
wildmulti‐levelprimatesociety.Current Biology,26(10),R403–R404.
https://doi.org/10.1016/j.cub.2016.03.062
SUPPORTING INFORMATION
Additional supporting information may be found online in the
Suppor tingInformationsectionattheendofthearticle.
How to cite this a rticl e:InmanVL ,LeggettKEA.
Observationsontheresponseofapodofhippostoadead
juvenilehippo(Hippopotamus amphibius,Linnaeus1758).Afr J
Ecol. 2019;00:1–3. ht tp s://doi.o rg /10.1111/aje.1 26 44
