DOI: 10.5061/dryad.n5tb2rc43
title: Data from: Reproductive ecology of the critically endangered pancake tortoise (Malacochersus tornieri) in the wild

description: Reproduction of the pancake tortoise in the wild has remained poorly known
 over the decades. This study fills the knowledge gap by investigating the
 reproductive ecology of the species in its natural habitats in Kenya. Data
 were collected using the time-constrained search-and-seize method,
 group-level scan sampling, radio tracking, and camera-trapping. Our
 observations revealed a total of 19 mating events that occurred between
 December and April, predominantly during the rainy seasons. Mating
 duration averaged 15.2±2.4 minutes. Male-male aggression was observed
 during the mating season, with the dominant male keeping off all other
 males and mating with the resident females. Nest preparation events
 occurred between April and June. Nine nesting events were recorded, but in
 only five of them was an egg deposited. The nests were dug in loose soil,
 appeared almost circular, and measured 8.4±0.9 cm wide and 7.0±0.1 cm deep
 (n=7). The average clutch size was one egg. The eggs were white,
 hard-shelled, oval, and elongated measuring 4.4±0.4 cm long, 2.7±0.04 cm
 wide and weighed 17±0.6 g (n=3). Incubation period lasted 177± 5.7 days
 (n=2), and hatching coincided with the onset of the short rainy season in
 November, aligned with the availability of abundant food for the
 tortoises. The hatchlings were minimally wider than long, having an
 average straight carapace length of 4.5±0.6 cm, an average width of
 4.5±0.4 cm, and on average weighed 14.7±3.7g, (N=9). They remained near
 the nest site for 4-5 days before relocating to tiny rock crevices away
 from the adult tortoise crevices. Egg and hatchling predation was high,
 with four of the total of six eggs, observed after they were laid, being
 destroyed. Three juveniles, out of nine, were also eaten by predators.
 These findings contribute useful information for the formulation of
 effective conservation and management strategies for this critically
 endangered species.
description: <em>Study area. — </em>The study was carried out in
 Kitui County, Kenya, between February 2020 and November 2022. The areas
 surveyed occur within latitudes 00<sup>o</sup> -
 01<sup>o</sup> south and longitudes 038<sup>o
 </sup>- 039<sup>o</sup> east and at an elevation ranging
 from 510 -775 m above sea level. In this region, populations of pancake
 tortoise are distributed discontinuously in a north-south orientation
 following the Precambrian basement system that has characteristic
 exfoliating granitic rock outcrops and kopjes with suitable crevices
 (Malonza 2003, Spawls et al. 2018). Soils here are generally sandy. The
 vegetation type of the region is mainly
 <em>Acacia</em>-<em>Commiphora</em> bushland,
 dominated by <em>Commiphora</em>, <em>Acacia</em>,
 <em>Grewia</em>, and <em>Combretum</em> (Wood and
 Mackay1997). The area experiences two short-lived rainy seasons between
 October and December, and March and June. Rains are erratic, and thus this
 region experiences frequent droughts. Rivers and streams are seasonal and
 usually exist as dry sandy river beds. Human residents often practice
 subsistence cultivation and pastoralism.
 <em>Time-constrained search-and-seize method. —
 </em>Between February and July 2020, rock crevices inhabited by
 pancake tortoises were identified through the time-constrained search and
 seize method as described by Karns (1986) and Sutherland (1996). Whenever
 possible, the tortoises therein were extracted (using a hooked stick),
 counted, and their sexes determined. Females have short stumpy tails and
 males have a characteristic thicker and more elongated tails (Malonza
 2003). Using a Vernier callipers, the straight carapace length (SCL),
 width (over the broadest part of the tortoise), and height (Ht) for each
 tortoise accessed were measured. Tortoises were also weighed and scute
 rings counted (SRC) in order to estimate their age (Germano 1994, Lagarde
 et al. 2001). Counting of the growth annuli was done mainly on the front
 costal scutes, which were less abraded.  During this time, any observation
 of reproductive behaviour was recorded.
 <em>Group-Level Scan Sampling. — </em>From July 2020
 to December 2022, group-level scan sampling (Van Belle 2017) was used to
 study the behaviour of pancake tortoises occupying 12 rock crevices
 (stations) in the Wingemei area in Nuu. In total, 39 tortoises were
 initially present in the crevices, and each of these was marked with a
 unique number on the carapace using a nontoxic-paint pen to enable us
 distinguish between different individuals. Monitoring visits were
 conducted regularly to the stations both during the dry and wet seasons,
 and on each visit the number of tortoises present in or near each crevice
 was recorded. Any breeding behaviour of the tortoises observed during each
 visit (i.e. pre-copulatory aggression, courting, mating, digging of nest,
 egg laying, and hatching) was recorded. The crevices were visited on a
 rotational basis, usually between 08:00 h -18:00 h. Thrice night visits to
 the crevices (between 19:00 h - 23:30 h) were done to observe the tortoise
 behaviour during these times. On two occasions, nesting females were also
 observed from evening into the night (16:00 - 21:30 h), using
 spotlights. During the nesting period, when nest
 digging behaviour was observed, researchers maintained a safe distance
 [8.3±3.2 m (SD), dependent on the physical habitat configuration] from the
 tortoises to avoid distracting them. All the nests located had their
 depth, width, and distance from the adult tortoise rock crevice measured.
 The soils at the nest sites were dug out to know the soil type and
 compaction. The plants overshadowing each nesting site were identified,
 and an approximation of their vertical sunlight shielding done by laying
 crown cover grids (0.5 m x 0.5 m) at the base of the plants, then
 estimating the percentage of the total grid area receiving shadow when the
 sun was overhead. Whenever an egg was laid, date and
 time were recorded. The soil covering it was carefully removed, the depth
 measured, and the orientation of the egg in the nest noted. Taking care
 not to break or turn it, the egg was carefully handled, and its length and
 breadth were measured using Vernier callipers. Its mass was weighed using
 a Pesola® (100g) micro-line 20100 balance (www.ecotone.pl). The colour and
 shape of the eggs were also noted. Finally, the egg was gently restored to
 its original position and orientation, and the soil and leaf litter,
 respectively, returned to cover the nest. The nests were geo-referenced
 and monitored (through daily visits) throughout the incubation period.
 After hatching, the hatchling length, width, and height were measured
 using Vernier calliper and its mass weighed using the Pesola® micro-line
 20100 balance. Their colour, shape, and behaviour (e.g. where they hid,
 number of days they stayed at the nest site before finding a new crevice)
 were also recorded. <em>Radio tracking. —
 </em>To enable us to closely follow and monitor the behaviour of
 individual pancake tortoises, 14 adult tortoises selected at random from
 different crevices in Wingemi area were fitted with 9g R1-2B radio
 transmitters (Holohil Systems Ltd, Ontario, Canada) and their movement was
 tracked using FCC ID: GZ383TTRX1000S radio receiver. The transmitters were
 fitted on the front costal (pleural) scute using clear hardened epoxy
 resin with the transmitter tail positioned slightly facing sideways in
 females to avoid obstruction during mating following guidelines in
 Goodlett et al. (1998). The radio-tracking process involved us visiting
 the tortoise crevices and observing if the radio-tagged tortoises were
 present. If not, then we switched on the radio-receiver and tracked the
 tortoise to its exact location. It was now possible to observe what the
 tortoise was doing, for instance, foraging, mating, nesting or perhaps if
 it shifted to a new crevice. <em>Camera-trapping.
 — </em>Four E1C EREAGLE (7.45mm lens) camera traps were deployed
 close to four of the pancake tortoise inhabited rock crevices (selected at
 random) and set in continuous recording video mode to collect tortoise
 behaviour near the crevices (Agha et al. 2015). Cameras enabled us to
 collect data on the time when the pancake tortoises exited and returned to
 their crevices. In cases where there was mating within the detection
 field, the camera recordings helped us to understand the time/seasons and
 frequency of mating by the tortoises. Furthermore, the camera traps helped
 us to gather data on other behaviour of the tortoises (e.g., fighting) in
 a 24-hour cycle non-invasively. After the eggs were laid, two of the
 camera traps were transferred from the adult tortoise camera stations and
 placed near and overlooking two of the nests (in continuous recording
 video mode) to record any activity around the nests (especially by
 predators) and to maximize the chances of capturing the hatching events
 (date and time of hatching, weather during hatching, activity by the
 hatchling after hatching). One camera was set on a tree overhanging a nest
 on 16 May 2022, and another was supported using a wooden pole in a
 close-up view above the second nest on 3 June 2022.
 <strong><em>References:</em></strong> Agha, M., Augustine, B., Lovich, J. E., Delaney, D., Sinervo, B., Murphy, M. O., Ennen, J. R., Briggs, J. R., Cooper, R. and Price, S. J. 2015. Using motion-sensor camera technology to infer seasonal activity and thermal niche of the desert tortoise (<em>Gopherus agassizii</em>). – <em>J. Therm. Biol. </em><strong>49:</strong> 119–126. http://www.sciencedirect.com/science/article/pii/S0306456515000273# Germano, D. J. 1994. Growth and age at maturity of North-American tortoises in relation to regional climates. – <em>Can. J. Zool.</em> <strong>72</strong>: 918–931. Goodlett, T., Goodlett, G. and Hamilton, P. 1998. Review of Radio Transmitter Attachment Techniques for Turtle Research and Recommendations for Improvement. – <em>Herpetol. Rev.</em> <strong>50(26)</strong>: 9 Karns, D. R. 1986. Field herpetology: Methods for the study of Amphibians and Reptiles in Minnesota. James Ford Bell Museum of Natural History, University of Minnesota. –<em>Occasional paper</em> <strong>18</strong>: 1–88. Lagarde, F., Bonnet, X. Henen, B. T. Corbin, J., Nagy, K. A. and Naulleau, G. 2001. Sexual size dimorphism in steppe tortoises (<em>Testudo horsfieldi</em>): growth, maturity, and individual variation. – <em>Can.</em><em> J. Zool</em>. <strong>79</strong>: 1433–1441. Malonza, P. 2003. Ecology and distributions of the pancake tortoise, <em>Malacochersus tornieri </em>in Kenya. – <em>J. East Afr. Nat</em>. <strong>92</strong>: 81–96. Spawls, S., Howell, K., Hinkel, H. and Menegon M. 2018. <em>A field Guide to East African reptiles</em>. – Bloomsbury Publishing. Sutherland, W. J. (Ed). 1996. Ecological census techniques. A handbook<em>. </em>–<em> </em><em>Cambridge</em> <em>University Press</em>, Cambridge. Van Belle, S. 2017. Observational Methods. In: Bezanson, M., Mackinnon, K. C., Riley, E., Campbell, C. J., Nekaris, K., Estrada, A., DiFiore, A. F., Ross, S., Joes-Engel, L. E., Thierry, B., Sussman, R. W., Sanz, C., Loudon, J., Elton S. and Feuntes, A. (Eds.). – <em>The International Encyclopedia of Primatology</em>, Wiley and Sons. Inc.  https://doi.10.1002/9781119179313.wbprim0385. Wood, R. C. and MacKay, A. 1997. The distribution and status of pancake tortoises, <em>Malacochersus tornieri</em>, in Kenya. In: Van Abbema, J. (ed.) – <em>Proceedings: Conservation, Restoration, and Management of Tortoises and Turtles</em> pp. 314–321.
description: # Data from: Reproductive ecology of the critically endangered pancake
 tortoise (Malacochersus tornieri) in the wild
 [https://doi.org/10.5061/dryad.n5tb2rc43](https://doi.org/10.5061/dryad.n5tb2rc43) *A brief summary of dataset contents, contextualized in experimental procedures and results:* The dataset herein provided includes information on adult tortoise morphometric measurements; computation of chi-square test to compare between males and female representation in the sampled population;  mating events as recorded on camera traps and through group-level scan sampling; nest characteristics, eggs laid and their measurements; incubation period,  and calculation of  hatching success rate; morphometric measurements of pancake tortoise hatchlings, and activity-time schedule for pancake tortoises from mating through hatching in the study area in Kitui county – Kenya  ## Description of the data and file structure The datasets are provided on different excel sheets, but in a single excel file for ease of access. Each excel sheet has a title for the subject addressed, is well labeled, and easy to understand. They offer detailed data which supports the information presented in the main article on the reproductive ecology of the pancake tortoise.