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RESEARCH COMMUNICATIONS
CURRENT SCIEN CE, VOL. 107, NO. 9 , 10 NOVEMBER 2 014 1595
*For correspondence. (e-mail: randeep04 @redi ffmail.com)
Strategy of female tigers to avoid
infanticide
Randeep Singh1 ,*, Parag Nigam1,
Qamar Qureshi1, Kalyanasundaram Sankar1,
Paul R. Krausman2 and
Surendra Prakash Goyal1
1Wildl ife Institu te of India, Post Box # 18 , D ehradun 24 8 001 , India
2Boone and C rockett Program in W ildli fe Con servation,
University of Mo ntana, Missoula, Montana 598 12, USA
In felids, mortality caused by dominant males can affect
life history characteristics, demography and repro-
ductive success. When a dominant male is removed,
an incoming male may kill offspring sired by the pre-
vious male to induce the resident female into oestrus.
We had the opportunity to observe the infanticide
avoidance responses of female tigers (Panthera tigris)
to incoming males in the core area of Ranthambhore
Tiger Reserve (RTR), Rajasthan, during 2008–2010.
In one case, following the disappearance of a domi-
nant male tiger (TM-12) from the established territory
of a female tiger (TF-13), the female tiger, accompa-
nied by two cubs, immediately moved approximately
20 km away into riverine areas outside the protected
area of RTR. In another case, a female (TF-04) died
from a battle with a male while defending her cubs.
These observations reveal the attempts of female
tigers to avoid infanticide. Observations and results
from behavioural decisions made by tigers are impor-
tant to understand the species and the factors that
facilitate their conservation.
Keywords: Camera trap, female tigers, infanticide avoid-
ance, Ranthambore Tiger Reserve.
IN carnivores, adult males play an important role in popu-
lation dynamics, reproduction and breeding success1 ,2.
Removal of adult territorial males can led to increased
immigration of new males, reduced survival of cubs and
reduced population growth3–7. In fanticide by imm igrating
males is a male reproductive strategy whereby new males
may kill the offspring sired by the dominant male to en-
able the mother to come into oestrus earlier (i.e. killing
for accelerated oestr ous cycle)8, 9. When females are faced
with these events they have behavioural options or counter
strategies to avoid infanticide, such as moving to an al-
ternative location outside th e new male’s territory or
staying to defend their cubs from attacks1 0–12. Moving to
an alternative location and avoiding the male could likely
lead to resettling in inferior habitat3, or enhance the
chances for injury and death if they have to repeatedly
defend their cubs from the males. These consequences on
the impacts of population dynamics have been rarely con-
sidered by biologists, partly due to the rare opportunities
to document this behaviour in the wild4,10.
Some records of females trying to avoid sexually
selected infanticide (i.e. when an immigrating male,
which is not the father of dependent cubs, may gain
increased mating success by killing the cubs) have been
documented for lions4 (Panthera leo), brown bears10
(Ursus arctos) and jaguars13 (Panthera onca), but similar
data for tigers (Panthera tigris) are limited to anacedontal
observations14 ,15. We report here the responses of two
female tigers to incoming immigrant males in order to
avoid infanticide.
The Ranthambhore Tiger Reserve (RTR; 2554N–
2612N and 7622E to 7639E) is situated in the semi-
arid part of western Rajasthan and is characterized by a
subtropical dr y climate with four distinct seasons: summer
(March–June), monsoon (July–August), post-monsoon
(September–October) and winter (November–February).
The study area has been described in detail by Singh
et al.16 .
The tiger population in RTR is composed of <30 ind i-
viduals in the past five years17,18. We monitored the tiger
population through camera traps (1 camera trap/km2) and
direct observations in 233 km2 of the core area in RTR
from April 2005 to June 2011 (refs 16, 19–22). We iden-
tified the distribution and home ranges of individual male
and female tigers and recorded population and reproduc-
tive parameters (i.e. inter-birth interval, dispersal, litter
size, age of first reproduction)16,1 9–22. Besides monitoring
individual tigers by camera trapping, we also used infor-
mation on tiger movements by intensive searching with
the Forest Department and direct sighting. If we found
tigers (inside or outside RTR) involved in conflicts with
humans, including killing livestock near human habita-
tions and attacking people, we photographed them
directly or with camera traps. We identified each tiger by
matching its stripe patterns with the tiger photo database
of RTR at the Wildlife Institute of India (WII),
Dehradun16. We marked the locations of tigers using a
handheld GPS device and plotted their locations in the
GIS domain using the ArcView 3.3 software package
(ESRI, Redlands, California, USA). We calculated the ae-
rial distance between the plotted locations. We observed
the behaviour of three tigers (one dominant male (TM-
12); one resident female (TF-13) and one incoming male
(TM-24)) during our study period. The home range of all
three tigers was calculated using the Home Range Exten-
sion in ArcView 3.3 to generate minimum convex pol y-
gons (MCPs)23 utilizing 100% of locations. We estimated
the home range of individuals that were encountered at
least three times at different locations during the study
period using the MCP method, because a minimum of
three points are needed to make a polygon. Additionally
the open, thorny, deciduous forest with scanty vegetation
and a good road network in RTR provide ideal
conditions for tiger sightings. We recorded additional
RESEARCH COMMUNICATIONS
CURRENT SCIEN CE, VOL. 107, NO. 9 , 10 NOVEMBER 2 014 1596
Figure 1. Distribution of thr ee tigers in Ra nthambhore Tiger Reserve, western I ndia, 200 8 to 2010 .
information about the behaviour (i.e. mating, scent spray-
ing, territorial marking, fight, prey hunting, rearing of
cubs) of male and female tigers.
In one case we observed that the female (TF-13) with
two cubs moved to a new area after the disappearance of
the dominant male tiger (TM-12). Before its disappear-
ance the male’s range covered the home range of the
female (Figure 1). In August 2008, female (TF-13) deli-
vered two cubs (M, F) and reared them until they dis-
persed. Subsequently, after 2 years, in August 2010, TF-
13 was photo-captured with two cubs (unknown sex). Be-
cause the male and female shared the same home range,
both litters were likely the progeny of the male TM-12.
After the emigration of male TM-12, the vacant home
range was acquired by another immigrant male (TM-24).
Evidence of this was confirmed by our regular monitor-
ing of tigers using camera traps (October 2010, adult
male TM-24 (> 3 years) was photo-trapped within the ter-
ritory of TF-13). This male tiger had been previously
physically captured approximately 4 km away in a subop-
timal habitat24. To possibly avoid infanticide, th e female
moved h er cubs to a new area approximately 20 km away
in riverine areas (Figure 1). Th e female (TF-13) and cubs
were confirmed by photographic evidence through cam-
era traps (December 2010) in the riverine area. Both the
female and the cubs were monitored continuously using
camera traps until the following monsoon (August 2011).
Our results highlight the response of a female tiger
with cubs (<6 month) to an immigrating male, including
avoidance of the new male. After the arrival of the new
male, the female left her established territory in which
she had successfully reared previous cubs. Similar female
strategies to avoid infanticide have been observed in sev-
eral species (felids, primates and captive rodents), thus
providing a mechanism whereby females may reduce
their losses to infanticide10. A few records of infanticide
have also been reported in tigers at the Kanha Tiger
Reserve, India (M. S. Panwar, unpublished) and Chitwan
National Park, Nepal1 4,15,25 . Sunquist26 also observed im-
migration of males after the death of a dominant male
tiger, which lead to fighting among them, and there was
no breeding for two years.
In another case we observed a female (TF-04) with
cubs vigorously attacking (2 April 2009) an intruding
male and successfully defending her cubs. The day after
the fight the female succumbed to injuries. The postmortem
report confirmed that the animal died due to deep canine
injuries in her skull and neck. This could be the immedi-
ate response of mothers against intruding males to pr e-
vent conspecifics from killing their offspring10,11 .
This study has recorded the response of a female tiger
to an immigrating male to likely avoid infanticide in a
semi-arid region in western India. This information
is important to better understand the behaviour of an
RESEARCH COMMUNICATIONS
CURRENT SCIEN CE, VOL. 107, NO. 9 , 10 NOVEMBER 2 014 1597
*For correspondence. (e-mail: dolenec@zg.biol.pmf. hr)
endangered species towards pr obable infanticide and
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ACKNOWLEDGEMENTS. We thank the D irector and Dea n, WII,
Dehra dun for thei r continuou s support. We also thank the Rajastha n
Forest Department and the pa rk offi cials and field staff at RTR for
permis sions and f or facilitating fi eld work. T his study was ma de possi -
ble by fina ncial and logi stic support from WII (Ministry of the Envi-
ronment and Forests, Government of India ).
Receiv ed 26 Ma y 201 4; revised a ccepted 2 4 Au gust 2014
Resource allocation within the
replacement clutch: do female
European starling (Sturnus vulgaris
Linneus) adjust their reproductive
strategy after a full clutch loss?
Ivna Kocijan1, Petra Dolenec2,
Zdravko Dolenec3,* and Andreja Radović4
1University o f Applied Health Studies, Mlinarska St. 38,
HR-10000 Zagreb, Cr oatia
2Department o f Pha rmacology, School of Medi cine,
University of Rijeka , Br a ć e Branchetta 20, HR-51000 , Rijeka, Croatia
3Department o f Zoology, Facu lty of Science, University of Zagr eb,
Rooseveltov trg 6, HR-10 000 Zagreb, Cr oatia
4Group for T errestria l Biodiversity, Divisio n of Biology,
Facu lty of Scien ce, Univer sity of Za greb, Maru lićev trg 20/II,
HR-10000 Zagreb, Croatia
An important factor in the evolution of reproductive
strategies in birds is the loss of a clutch or a brood.
Many avian species produce a replacement clutch fol-
lowing the loss of the first clutch, but additional
breeding effort carries physiological costs and can
also reduce female fitness. Thus, egg production in
replacement clutches is usually reduced. In contrast,
European starling mothers seem to invest equally in
their first and replacement clutches. This study inves-
tigated whether female starlings use differential allo-
cation of resources to offspring, rather than egg
production, to strategically balance investment and