DOI: 10.5061/dryad.qbzkh18qz
title: Successful conservation translocation: Population dynamics of tiger recovery in Panna Tiger Reserve, Central India

description: Tiger (Panthera tigris) is an indicator species of ecological health and
 conservation efforts. Due to excessive poaching, the tiger was locally
 extinct in Panna Tiger Reserve, central India. Subsequent successful
 reintroduction efforts have brought the species back from the verge of
 extinction and have demonstrated the success of conservation
 translocations in response to such critical situations. To understand the
 demographic characteristics of the tigers reintroduced to Panna Tiger
 Reserve, we used an ensemble approach of different sampling techniques and
 direct observations from a long-term data-set spanning more than 10 years.
 We evaluated different demographic indicators (population status, growth
 rate, mean litter size, inter-birth interval, and survival probability).
 Since reintroduction in 2009, 18 females have recruited 120 cubs from 45
 litters. This led to 59 individuals in 2021 with a growth rate of ~26%.
 The mean litter size was 2.66 (SE 0.1), and the inter-birth interval was
 19.16 months (SE 0.5). The high survival rate of the reintroduced
 population (0.82±0.2) helped to achieve the success of reintroduction. We
 observed non-constant mortality trajectories for both sexes (higher
 survival probabilities for females) with a moderately higher risk of death
 in younger (&lt;1 year) and older (&gt;10 years) individuals. Our
 results showed the effectiveness of translocation and conservation
 efforts. The recovered population can be used as a founder for
 augmentation in other recovering tiger populations. A long-term
 tiger-centric management plan should be implemented in the area adjacent
 to Panna Tiger Reserve to conserve and secure the habitat of the entire
 landscape for the long-term survival of the reintroduced population in a
 metapopulation framework.
description: <strong>Data Collection</strong>
 <strong><em>Radio
 telemetry</em></strong> A total of 25
 tigers (7 males and 18 females; Table S1) were radio-collared between
 March 2009 and June 2020 as a part of the long-term project entitled
 “Tiger Reintroduction and Recovery Programme in Panna Tiger Reserve,
 Madhya Pradesh.” Animals were captured and collared under the permission
 of the Madhya Pradesh Forest Department (MPFD Letter No./Exp./2009/1205
 dated 31/8/09) following the capture rule and regulation of the Wildlife
 Protection Act, 1972 Section 11 (1A). Animals were tracked and
 immobilized, using a ‘Hellabrunn mixture’ (125 mg xylazine + 100 mg
 ketamine/ml) (Hafner et al<em>.,</em> 1989) injected through a
 Tele-inject projector (Model 4V.31). The target individuals were
 chemically immobilized. The entire process took place under the
 supervision of a veterinarian. Tigers were fitted with Very High Frequency
 transmitters (15 individuals; Telonics® Inc) and VHF/ GPS/ UHF collars (10
 individuals; African Wildlife Tracking<sup>®</sup> Inc and
 Vetronic Aerospace<sup>®</sup>). All collared tigers were
 monitored very intensively with UHF and satellite tools. Staff and
 researchers jointly monitored VHF collared individuals and tracked the
 animals 24 hours per day, 7 days per week for the duration of the
 study. <strong><em>Camera
 trapping</em></strong> Grid-based
 systematic camera trap sampling was carried out from 2012-2016 in a
 4km<sup>2</sup> grid cell size; a more intensive effort took
 place from 2017-2021 with a 2km<sup>2</sup> grid cell size
 (Jhala et al., 2019). The entire PTR was sampled systematically by placing
 a pair of camera traps (531 locations) on either side of dirt roads,
 animal trails, or dry river beds to maximize the chances of capturing
 tigers on camera. Camera traps were active for at least 30 days during the
 winter season. In addition to the double-sided camera traps, a
 single-sided continuous camera trap monitoring system (CCMS) was adapted
 to monitor the movement of non-collared tigers throughout the year. We
 used a grid-based approach (same 2km<sup>2</sup> grid cell
 size) for CCMS to sample throughout PTR. Simultaneously, camera traps were
 also placed opportunistically at vantage points, kills, and nearby den
 sites. Cameras were checked every 5-7 days. Individually identifiable
 tiger pictures, including both flanks, were updated every year. Newly
 captured tiger images were compared manually by using their respective
 unique stripe patterns. The intensive use of
 radio-telemetry and camera trapping helped us to document the emigration
 of tigers from PTR. As there are no other source populations around PTR,
 we did not record any immigration events during 2009-2021. Routine
 patrolling with elephants, camera traps, and intensive radio-telemetry
 helped us to quantify the IBI, initial litter size and cub
 survival. <strong>Analytical
 methods</strong>
 <strong><em>Population status and growth
 rate</em></strong> All adult and sub-adult
 tigers were radio-collared during the initial days after reintroduction.
 With a growing tiger population, all individuals were not radio-tagged;
 therefore, the camera trap-based survey method was adapted to understand
 the movement of non-collared animals. To calculate the growth rate of
 tigers, we used the software Vortex version 10 (Lacy & Pollak,
 2014) with 100 iterations. Vortex is appropriate for modelling species
 with low fecundity and long life spans and is the most commonly used
 software in published reintroduction models (Armstrong & Reynolds,
 2012). The growth rate (r) of <em>r</em> &gt; 0 indicates
 the population grows, while <em>r</em> &lt; 0 indicates a
 population decline. Similarly, the annual multiplicative growth rate (λ)
 indicates a positive population growth if λ &gt; 1.0
 (N<sub>t+1</sub> &gt; N<sub>t</sub>), while λ
 &lt; 1.0 (N<sub>t+1</sub> &lt;
 N<sub>t</sub>) indicates a population decline.
 <strong><em>Litter size and inter-birth
 interval</em></strong> Tiger individuals
 were identified by their unique stripe patterns (McDougal, 1977; Karanth,
 1995) on their left and right flanks. Recording and documenting actual
 litter size at birth for any free-ranging elusive large carnivores is
 difficult; therefore, we determined the litter size of the tiger at the
 first sighting. Once the first sight or photo captured of the female with
 cubs was recorded, the approximate date of birth of the cubs was estimated
 by deducting two months from the first appearance (Smith et al., 1987).
 However, for collared females, the litter size or date of birth of cubs
 was confirmed by the direct sighting, using radio-telemetry tracking. The
 IBI was calculated when the same female produced second or consecutive
 successful litters. We assumed the cubs were dead, if not photo captured
 or found to be moving with mothers for more than six months. Usually,
 females conceive and give birth to another litter within 4-10 months after
 losing all cubs of the previous litter; such instances were discarded for
 IBI calculations (Singh et al., 2013). Since our monitoring was intensive,
 we had a high detection of tigers during the study period, except for when
 the individuals dispersed outside the PTR.
 <strong><em>Survivorship</em></strong> The detection non-detection matrix was prepared by compiling camera trap, CCMS, and radio-telemetry (to ensure whether the individual was within the PTR or not) data, and data were analyzed in the Capture-Mark-Recapture (CMR) framework (Table S1); since the detection probability of an animal within its home range was not involved in our study, imperfect detection was intentionally not addressed in our analysis. We used the Cormack-Jolly-Seber (CJS; Pledger et al., 2003) method to estimate the survival rate from one sampling period to the next; the survival rate is calculated as a proportion of animals alive at time <em>t<sub>i</sub></em> versus time <em>t<sub>i+1</sub></em>.<em><sub> </sub></em>Survival (<em>ϕ</em>) and recapture probability<em><sub> </sub></em>(<em>p</em>) depend on marked individuals' re-observation. Sex of each tiger, an intrinsic factor, and time (extrinsic factor) were included as covariates in the model of survival rate. As males and females have different life history traits, their survival probabilities might differ (Smith, 1993). Males show a lower survival probability than females in most mammalian species (Krebs, 1972). We modelled the survival probability using the ‘marked’ package (Laake et al., 2013) in R Core Team (2022). The Akaike Information Criterion (AIC) value was calculated for every model to determine the best fit model.
description: Successful conservation translocation: population dynamics of tiger
 recovery in Panna Tiger Reserve, Central India
 [https://doi.org/10.5061/dryad.qbzkh18qz](https://doi.org/10.5061/dryad.qbzkh18qz) Description of the data and file structure Details of individual animals, including birth year, death year, capture matrix, sex, and monitoring strategy. This dataset is a part of the long-term project entitled “Tiger Reintroduction and Recovery Programme in Panna Tiger Reserve, Madhya Pradesh.” We have submitted the raw data (tiger demography.csv). The column Animal ID: Represents the individuals Birth: Year of birth of the animal Death: Year of death of the animal (here, 0 represents that the animal is still alive) 2009-2021: Representing the year-wise study period. (Here, 0 represents that individual was undetected, while, 1 represents detection of the individual) Sex: Sex of the individual; M = Male, F = Female Data collection: Individual's data was collected through both invasive and non-invasive method. Data was collected through systematic camera trapping and radio-collar (to ensure whether the animal was present within the study area or not, please see the methodology section for further details). The dataset was prepared as recommended by Colchero and Clark, (2012). The code (R Studio) can be obtained from Colchero, Jones and Rebke, (2012). Colchero, F. and J.S. Clark (2012) **Bayesian inference on age-specific survival for censored and truncated data.** *Journal of Animal Ecology,* 81, 139-149. Colchero, F., O.R. Jones and M. Rebke (2012) **BaSTA: an R package for Bayesian estimation of age-specific survival from incomplete mark-recapture/recovery data with covariates.** *Methods in Ecology and Evolution*. 3: 466-470.