Temporary Emigration Research Articles

Effects of nature-based tourism and environmental drivers on the demography of a small dolphin population

Many marine top predators are experiencing significant declines due to anthropogenic impacts, and therefore reliable monitoring is essential to understand their population dynamics. We used Pollock's robust design capture–recapture modelling to assess the influence of oceanographic variables, artisanal fisheries and human disturbance on several demographic parameters (abundance, temporary emigration and survival) of the Indo-Pacific bottlenose dolphin (Tursiops aduncus), using long-term data on marked individuals from East Africa. Photo-identification data was collected over 551 boat-based surveys between 2006 and 2009, with 137 individuals identified. Our best fitting model indicated that exposure to tourism (represented by the number of tourist boats) increased the probability of dolphins seasonally emigrating from the study area. The return rate of temporary emigrants was negatively linked to the seasonal sea surface temperature, probably associated with food availability. That model supported the existence of heterogeneity in annual local survival estimates, with transient dolphins showing a lower value than resident individuals (0.78 and 0.98, respectively). Furthermore, abundance estimates showed a small population size ranging from 19 individuals (95% CI: 11–33) to a maximum of 104 dolphins (95% CI: 78–139). This small population, together with their high site fidelity and coastal distribution, might be particularly vulnerable to human disturbances. This study highlights the influence of environmental and anthropogenic factors on dolphin demography and population dynamics and the need to integrate these drivers to provide robust evidences for conservation stakeholders in an adaptive management framework.

Sex-Specific Patterns in Abundance, Temporary Emigration and Survival of Indo-Pacific Bottlenose Dolphins (Tursiops aduncus) in Coastal and Estuarine Waters

Inherent difficulties in determining the sex of free-ranging sexually monomorphic species often prevents a sex-specific focus on estimating abundance, movement patterns and survival rates. This study provides insights into sex-specific population parameters of Indo-Pacific bottlenose dolphins (Tursiops aduncus). Systematic, boat-based photo-identification surveys (n = 417) were conducted year-round from 2007-2013 in coastal and estuarine waters off Bunbury, Western Australia. Pollock’s Robust Design was used to quantify population parameters for three datasets: i) adults and juveniles combined, ii) adult females and iii) adult males. For all datasets, abundance estimates varied seasonally, with general highs during summer and/or autumn, and lows during winter. Dolphins had seasonally structured temporary emigration rates with similar trends between sexes. The derived return rate (1-γ’) of temporary emigrants into the study area was highest from winter to spring, indicating that dolphins had a high probability of return into the study area during spring. We suggest that the return of dolphins into the study area and increase in abundance is influenced by the breeding season (summer/autumn). Prey availability is likely a main driver responsible for the movement of dolphins out of the study area during winter. Seasonal apparent survival rates were constant and high (0.98-0.99) for all datasets. High apparent survival rates suggest there is no permanent emigration from the study area. Our sex-specific modeling approach offers a comprehensive interpretation of the population dynamics of a top predator in a coastal and estuarine environment and acts as a model for future sex-based population studies on sexually monomorphic species.

Robust estimation of survival and contribution of captive‐bred Mallards Anas platyrhynchos to a wild population in a large‐scale release programme

The survival of captive‐bred individuals from release into the wild to their first breeding season is crucial to assess the success of reintroduction or translocation programmes, and to assess their potential impact of wild populations. However, assessing the survival of captive‐bred individuals following their release is often complicated by immediate dispersal once in the wild. Here, we apply Lindberg's robust design model, a method that incorporates emigration from the study site, to obtain true estimates of survival of captive‐bred Mallards Anas platyrhynchos, a common duck species released on a large scale in Europe since the 1970s. Overall survival rate from release in July until the onset of the next breeding season in April was low (0.18 ± 0.07 se) and equivalent to half the first‐year survival of local wild Mallards. Higher overall detectability and temporary emigration during the hunting period revealed movements in response to hunting pressure. Such low survival of released Mallards during their first year may help prevent large‐scale genetic mixing with the wild population. Nevertheless, by combining our results with regional waterfowl counts, we estimated that a minimum of 34% of the Mallards in the region were of captive origin at the onset of the breeding season. Although most released birds quickly die, restocking for hunting may be of sufficient magnitude to affect the wild population through genetic homogenization or loss of local adaptation. Robust design protocols allow for the estimation of true survival estimates by controlling for permanent and temporary emigration and may require only a moderate increase in fieldwork effort.

Estimating density of a rare and cryptic high-mountain Galliform species, the Buff-throated Partridge Tetraophasis szechenyii

Xu, Y., B. Wang, L. Dou, H. Yue, N. Yang, L. Yang, S. Liu, and J. Ran. 2016. Estimating density of a rare and cryptic high-mountain Galliform species, the Buff-throated Partridge Tetraophasis szechenyii. Avian Conservation and Ecology 11(1):10.http://dx.doi.org/10.5751/ACE-00853-110110

Experimental effects of early‐life corticosterone on the hypothalamic–pituitary–adrenal axis and pre‐migratory behaviour in a wild songbird

Summary Although laboratory studies have shown that chronic exposure to elevated glucocorticoids during development can have profound effects on the physiology and behaviour of animals, we still have a poor understanding of the proximate and ultimate consequences of early life stress on individuals in the wild. In an island population of Savannah sparrows (Passerculus sandwichensis), we examined multiple hypotheses to explain how elevated glucocorticoid exposure during the nestling period influenced both hypothalamic–pituitary–adrenal (HPA) axis function during the nestling period and the subsequent movement and survival of young after they fledged the nest. We exposed nestlings to exogenous corticosterone from 2 to 6 days of age and then measured both baseline and stress‐induced (30‐min restraint) plasma corticosterone levels prior to fledging (day 7). We then recaptured young throughout the pre‐migratory period and used mark–recapture analysis to estimate temporary emigration from the capture site (movement) and survival. Corticosterone‐treated nestlings had higher baseline corticosterone levels and lower stress reactivity than untreated individuals, and were more sensitive to inclement weather. Although there was no evidence that corticosterone treatments influenced survival, treated individuals had higher rates of temporary emigration outside of the study site than sham or controls. Our results provide support for the ceiling hypothesis, which suggests that individuals with chronic elevated glucocorticoids can lead to a dampened HPA axis response. We also provide support for the CORT‐activity hypothesis, which suggests that elevated glucocorticoids can increase activity levels, at least 1–2 months after leaving the nest. Our study highlights the importance of tracking individuals across multiple stages of the annual cycle to understand how early life events carry over to influence both physiology and behaviour.

Why High School Students Aspire to Emigrate: Evidence from Greece

This paper investigates why Greek high school students aspire to emigrate, in relation to their educational and socio-economic background. Through fieldwork research conducted at three specialist high schools in Thessaloniki, three main conclusions have been drawn. Firstly, potential emigrants are ambitious, with high educational and professional expectations and a clear migration plan. Secondly, they are middle and upper middle class and excel at school—in socio-economic and educational terms, they therefore constitute the most dynamic Greek youths. Thirdly, in a period of recession on a European level, the alarming fact is that student emigration can undermine recovery for a country in crisis such as Greece. That is, middle-class shrinkage caused by the recession can be aggravated by emigration, which in turn might cost the loss of developmental human resources for Greece and a deepening of the recession. This can further stimulate migration, resulting in a vicious circle between crisis and emigration. Furthermore, if potential emigrants do not return because temporary emigration for studies becomes permanent migration for work, the economic crisis is worsened, and Greece’s prospects for development are further undermined.

Are Private Reserves Effective for Jaguar Conservation?

We present the first study of density and apparent survival for a jaguar (Panthera onca) population in northern Mexico using 13 years of camera trap data from 2000 to 2012. We used the Barker robust design model which combines data from closed sampling periods and resight data between these periods to estimate apparent survival and abundance. We identified 467 jaguar pictures that corresponded to 48 jaguar individuals. We included camera type and field technician as covariates for detection probabilities. We used three covariates to evaluate the effect of reserve on jaguar apparent survival: i) private reserve creation ii) later reserve expansions, and iii) cattle ranches’ conservation activities. We found that the use of digital cameras in addition to film cameras increased detection probability by a factor of 6x compared with the use of only film cameras (p = 0.34 ± 0.05 and p = 0.05 ± 0.02 respectively) in the closed period and more than three times in the open period (R = 0.91 ± 0.08 and R = 0.30 ± 0.13 mixed and film cameras respectively). Our availability estimates showed no temporary emigration and a fidelity probability of 1. Despite an increase of apparent survival probability from 0.47 ± 0.15 to 0.56 ± 0.11 after 2007, no single covariate explained the change in these point estimates. Mean jaguar density was 1.87 ± 0.47 jaguars/100 km2. We found that 13 years of jaguar population monitoring with our sampling size were not enough for detecting changes in survival or density. Our results provide a baseline for studies evaluating the effectiveness of protected areas and the inclusion of ranch owners in jaguar conservation programs and long-term population viability.

An Evaluation of Streamflow Augmentation as a Short-Term Freshwater Mussel Conservation Strategy

Recurrent and prolonged droughts, coupled with increased water resource demand, threaten freshwater mussel populations through stream drying and water quality degradation. Augmentation of stream discharge was proposed as a short-term strategy to maintain adequate streamflows and water quality in reaches with important freshwater mussel populations during exceptionally low flow periods. We investigated the effects of water augmentation on seven freshwater mussel species in a small creek between 2011 and 2014. Using capture-mark-recapture methods, we monitored mussel populations in a control reach upstream of an augmentation outlet and two reaches immediately downstream of an augmentation outlet. Water quality measurements during our study indicated that augmentation improved water temperature and dissolved oxygen conditions during low flow periods. For all mussel species, apparent survival was positively related to minimum streamflows and declined precipitously as streamflows decreased. However, mean apparent survival between sampling occasions was high among all species but did not differ among treatment units, suggesting that flow augmentation rates in this study were insufficient for abating the effects of basin-wide reductions in streamflow. Temporary emigration differed among study reaches but did not support hypothesized relationships because it increased with stream stage and was highest in an augmented reach. This suggests that streamflows did not drop below thresholds, which invoked burrowing as a response to decreased streamflows. Streamflow augmentation may be a viable short-term mussel conservation strategy in small streams but will likely require higher augmentation volume capacity than evaluated during our study. Copyright © 2015 John Wiley & Sons, Ltd.

The impact of temporary migration for demographic perspective in Poland

The National Population Census 2011 showed that over 2 million of Polish citizens have been temporarily staying abroad for at least 3 months. The aim of analysis is to present an impact of temporary emigration on the present and future demographic situation of our country, especially the change in the population size and number of births, as well as the advancement of aging process in the coming years. The results of the census 2011 indicate that the population losses due to temporary emigration may exceed 10% in the age groups 25–29 and 30–34. The results for 2014–2050 based on the CSO modified forecast including temporary emigration and immigration show a relevant decrease in the number of population at the age of economic activity. The possible return of emigrants could counteract the depopulation of our country, but in the long run will be intensified by the aging of the population.

Abundance and demography of bottlenose dolphins inhabiting a subtropical estuary in the Southwestern Atlantic Ocean

We conducted a mark-recapture (MR) analysis from 8 years (2005–2012) of photo-identification data collected systematically to investigate demographic parameters of a community of bottlenose dolphins (Tursiops truncatus) inhabiting the Patos Lagoon Estuary and adjacent marine coast in southern Brazil. Under the most parsimonious model of Pollock’s robust design, which disregarded the effects of temporary emigration, the estimate of annual apparent survival was higher for adult females (0.97, 95% CI: 0.91–0.99) than for adult males (0.88, 95% CI: 0.75–0.94) and juveniles (0.83, 95% CI: 0.64–0.93), which may explain an observed bias in sex ratio (1 male:2 females) of known adult dolphins in this community. An increase in abundance of marked individuals was observed during the first 6 years of sampling when the number of new recruits surpassed mortality, followed by a remarkable decrease in the last 2 years when an inverse ratio of recruits/deaths occurred. Yearly changes in abundance (� � t) varied from −0.1 to 0.07. Total abundance estimates were highly precise (the highest coefficient of variation was 0.053) and did not exceed 88 individuals. Abundance estimates were similar to a previous MR study conducted in the same area almost a decade earlier, suggesting a relative stable dolphin community over the last 14 years. The apparent stability in abundance, however, should be viewed with caution since this community would need a substantial mortality of at least 10% before a decline in abundance is detected with a desirable statistical power of 90%.

Partitioning detectability components in populations subject to within-season temporary emigration using binomial mixture models.

Detectability of individual animals is highly variable and nearly always < 1; imperfect detection must be accounted for to reliably estimate population sizes and trends. Hierarchical models can simultaneously estimate abundance and effective detection probability, but there are several different mechanisms that cause variation in detectability. Neglecting temporary emigration can lead to biased population estimates because availability and conditional detection probability are confounded. In this study, we extend previous hierarchical binomial mixture models to account for multiple sources of variation in detectability. The state process of the hierarchical model describes ecological mechanisms that generate spatial and temporal patterns in abundance, while the observation model accounts for the imperfect nature of counting individuals due to temporary emigration and false absences. We illustrate our model’s potential advantages, including the allowance of temporary emigration between sampling periods, with a case study of southern red-backed salamanders Plethodon serratus. We fit our model and a standard binomial mixture model to counts of terrestrial salamanders surveyed at 40 sites during 3–5 surveys each spring and fall 2010–2012. Our models generated similar parameter estimates to standard binomial mixture models. Aspect was the best predictor of salamander abundance in our case study; abundance increased as aspect became more northeasterly. Increased time-since-rainfall strongly decreased salamander surface activity (i.e. availability for sampling), while higher amounts of woody cover objects and rocks increased conditional detection probability (i.e. probability of capture, given an animal is exposed to sampling). By explicitly accounting for both components of detectability, we increased congruence between our statistical modeling and our ecological understanding of the system. We stress the importance of choosing survey locations and protocols that maximize species availability and conditional detection probability to increase population parameter estimate reliability.

Brain drain, brain gain, and economic growth in China

We have used Chinese provincial data (1980–2005) to examine the effects of permanent and temporary emigration on human capital formation and economic growth in source regions. First, we find that permanent emigration is conducive to the improvement of both middle and high school enrollment. In contrast, while temporary emigration has a significantly positive effect on middle school enrollment it does not affect high school enrollment. Moreover, the different educational attainments of temporary emigrants have different effects on school enrollment. Specifically, the proportion of temporary emigrants with high school education positively affects middle school enrollment, while the proportion of temporary emigrants with middle school education negatively affects high school enrollment. Finally, we find that both permanent and temporary emigration has a detrimental effect on the economic growth of source regions.

Estimating abundance of unmarked animal populations: accounting for imperfect detection and other sources of zero inflation

SummaryInference and estimates of abundance are critical for quantifying population dynamics and impacts of environmental change. Yet imperfect detection and other phenomena that cause zero inflation can induce estimation error and obscure ecological patterns.Recent statistical advances provide an increasingly diverse array of analytical approaches for estimating population size to address these phenomena.We examine how detection error and zero inflation in count data inform the choice of analytical method for estimating population size of unmarked individuals that are not uniquely identified. We review two established (GLMs and distance sampling) and nine emerging methods that useN‐mixture models (Royle–Nichols model, and basic, zero inflated, temporary emigration, beta‐binomial, generalized open‐population, spatially explicit, single visit and multispecies) to estimate abundance of unmarked populations, focusing on their requirements and how each method accounts for imperfect detection and zero inflation.Eight of the emerging methods can account for both imperfect detection and additional variation in population size in the forms of non‐occupancy, temporary emigration, correlated detection and population dynamics.Methods differ in sampling design requirements (e.g. count vs. detection/non‐detection data, single vs. multiple visits, covariate data), and their suitability for a particular study will depend on the characteristics of the study species, scale and objectives of the study, and financial and logistical considerations.Most emerging methods were developed over the past decade, so their efficacy is still under study, and additional statistical advances are likely to occur.

Accounting for Recent Fertility Swings in Cuba

In 2006, Cuba's TFR had declined to 1.39, a level nearly comparable to those found in ultra‐low‐fertility but far richer European and Asian countries. Given the vast economic differences, Cuba's very low fertility was anomalous. Since 2006, and in tandem with what has occurred in many other low‐fertility countries, the Cuban TFR has increased. This article contends that the TFR increase largely was a response to improvements in the welfare of individual households—and thus, in their financial ability to have children. These improvements were the result of considerable permanent and temporary labor emigration, which together with US and Cuban policy changes, led to a surge in remittances and contributed to easing Cuba's perennial housing shortage.

Whooping crane demographic responses to winter drought focus conservation strategies

Focusing conservation strategies requires identifying the demographic parameters and environmental conditions affecting the growth of animal populations most. Therefore, we examined relationships between population demographics and winter drought (1950–2011) for endangered whooping cranes (Grus americana) wintering in Texas, USA. We modeled winter loss and its contribution to annual mortality as functions of winter drought, determined recruitment needed to maintain population growth after drought, and identified which demographic parameters underpin this population’s growth. Previous research assumed winter loss (i.e., birds missed in subsequent surveys) represented mortality. We show that loss includes temporary emigration to upland habitats, early migration, and incomplete detection. Despite this, we maintained this assumption to evaluate the relevance of winter mortality to population growth. We found that winter loss (β^=-0.308, SE=0.042) and its contribution to annual mortality (β^=-0.318, SE=0.047) increased with drought severity (Palmer hydrological drought index; PHDI). Given average recruitment (0.145, SD=0.090), this population increases 1.2% (95% CI=−2.9% to 4.2%) after extreme drought (PHDI=−4). No recruitment must occur for 3years with moderate to severe drought (PHDI<−2.5) to delay species’ recovery ≈7years. This scenario has not occurred since population monitoring began in 1938. Of the demographic parameters we examined, winter loss explained population growth least (14.4%; 95% CI=3.6–35.8%), and it was partially compensatory. Breeding–migratory mortality explained 42.2% (95% CI=19.1–61.5%) of population growth and recruitment 49.9% (95% CI=20.6–75.2%). Our results focus conservation on breeding and migratory periods, and deemphasize winter mortality and drought. On the wintering grounds, conservation of whooping cranes should emphasize maintaining coastal, upland, and interior habitats for this population.

Overlooking a potential hotspot at Great Barrier Island for the nationally endangered bottlenose dolphin of New Zealand

Conservation initiatives are typically constrained by economic circumstances, a fac- tor certainly true for marine mammal conservation in New Zealand. Most research in this field has been conducted following concerns over anthropogenic impacts on populations and has therefore been funded and/or driven by stakeholder interest. Bottlenose dolphins Tursiops truncatus are classified as 'Nationally Endangered' in New Zealand waters. Here, we present the first study on occurrence, site fidelity and abundance of this species off Great Barrier Island (GBI), a previously overlooked region within the home range of the North Island population. Dedicated boat-based photo-identification surveys were conducted monthly from 2011−2013, resulting in 1412 sighting records of 154 individuals. Dolphins were recorded during all months of the year, with a higher probability of encounter in deeper waters during summer and shallower waters during winter and spring. Group sizes (median = 35, mean = 36) were higher than previously reported for this popu- lation in other regions. Individual re-sighting patterns were variable; however, overall site fidelity was high (mean monthly sighting rate = 0.33). A Robust Design approach resulted in seasonal fluctuations in abundance and temporary emigration. Based on a super-population estimate, 171 dolphins (CI = 162−180) visited the area during 2011−2013. Our data suggest that GBI is a poten- tial hotspot for bottlenose dolphins of the North Island population rather than a corridor to reach other destinations. We highlight the need for researchers, managers and funding agencies to con- sider the entire range of a population when conducting or funding research.

Environmental correlates of temporary emigration for female Weddell seals and consequences for recruitment

In colonial‐breeding species, prebreeders often emigrate temporarily from natal reproductive colonies then subsequently return for one or more years before producing young. Variation in attendance–nonattendance patterns can have implications for subsequent recruitment. We used open robust‐design multistate models and 28 years of encounter data for prebreeding female Weddell seals (Leptonychotes weddellii [Lesson]) to evaluate hypotheses about (1) the relationships of temporary emigration (TE) probabilities to environmental and population size covariates and (2) motivations for attendance and consequences of nonattendance for subsequent probability of recruitment to the breeding population. TE probabilities were density dependent (βˆBPOP = 0.66, = 0.17; estimated effects [β] and standard errors of population size in the previous year) and increased when the fast‐ice edge was distant from the breeding colonies (βˆDIST = 0.75, = 0.04; estimated effects and standard errors of distance to the sea‐ice edge in the current year on TE probability in the current year) and were strongly age and state dependent. These results suggest that trade‐offs between potential benefits and costs of colony attendance vary annually and might influence motivation to attend colonies. Recruitment probabilities were greatest for seals that consistently attended colonies in two or more years (e.g., = 0.56, SD = 0.17) and lowest for seals that never or inconsistently attended prior to recruitment (e.g., = 0.32, SD = 0.15), where denotes the mean recruitment probability (over all years) for 10‐year‐old seals for the specified prebreeder state. In colonial‐breeding seabirds, repeated colony attendance increases subsequent probability of recruitment to the adult breeding population; our results suggest similar implications for a marine mammal and are consistent with the hypothesis that prebreeders were motivated to attend reproductive colonies to gain reproductive skills or perhaps to optimally synchronize estrus through close association with mature breeding females.

Apparent Survival of Woodpeckers and Nuthatches in Wisconsin

Few annual survival and capture-probability estimates exist for sittid and picid species common in North America. We used a mark—recapture study and robust design analysis in Program MARK to estimate annual survival rates based on a sample of 51 Sitta carolinensis (White-breasted Nuthatch), 12 Picoides pubescens (Downy Woodpecker), and 15 Picoides villosus (Hairy Woodpecker) wintering in central Wisconsin, 2006–2013. Apparent survival probability was similar between the two woodpecker species (Downy Woodpecker: p = 0.51, 95% CI = 0.34–0.68; Hairy Woodpecker: p = 0.52, 95% CI = 0.36– 0.68). Apparent annual survival modeled as constant across time was low for both sexes of White-breasted Nuthatch (0.25 [CI = 0.12–0.44] and 0.28 [CI = 0.14–0.49] for males and females, respectively), but there was some evidence for annual variation in survival. All three species showed evidence for a trap-happy response in which recapture probability was higher than original capture probability, but it was stronger in the White-breasted Nuthatches than the two woodpecker species. There is little evidence of temporary emigration for any of the woodpecker taxa we studied. Our results provide baseline demographic data for these species in Wisconsin and will be useful in planning future trapping studies.

Vigorous dynamics underlie a stable population of the endangered snow leopard Panthera uncia in Tost Mountains, South Gobi, Mongolia.

Population monitoring programmes and estimation of vital rates are key to understanding the mechanisms of population growth, decline or stability, and are important for effective conservation action. We report, for the first time, the population trends and vital rates of the endangered snow leopard based on camera trapping over four years in the Tost Mountains, South Gobi, Mongolia. We used robust design multi-season mark-recapture analysis to estimate the trends in abundance, sex ratio, survival probability and the probability of temporary emigration and immigration for adult and young snow leopards. The snow leopard population remained constant over most of the study period, with no apparent growth (λ = 1.08+−0.25). Comparison of model results with the “known population” of radio-collared snow leopards suggested high accuracy in our estimates. Although seemingly stable, vigorous underlying dynamics were evident in this population, with the adult sex ratio shifting from being male-biased to female-biased (1.67 to 0.38 males per female) during the study. Adult survival probability was 0.82 (SE+−0.08) and that of young was 0.83 (SE+−0.15) and 0.77 (SE +−0.2) respectively, before and after the age of 2 years. Young snow leopards showed a high probability of temporary emigration and immigration (0.6, SE +−0.19 and 0.68, SE +−0.32 before and after the age of 2 years) though not the adults (0.02 SE+−0.07). While the current female-bias in the population and the number of cubs born each year seemingly render the study population safe, the vigorous dynamics suggests that the situation can change quickly. The reduction in the proportion of male snow leopards may be indicative of continuing anthropogenic pressures. Our work reiterates the importance of monitoring both the abundance and population dynamics of species for effective conservation.

To catch or to sight? A comparison of demographic parameter estimates obtained from mark-recapture and mark-resight models

Accurate assessments of population parameters, such as survival and abundance, are critical for effective wildlife conservation. In order for wildlife managers to undertake long-term monitoring of populations, the data collection must be as cost-effective as possible. Two demographic modelling techniques commonly used are mark-recapture and mark-resight. Mark-resight can be used in conjunction with biotelemetry methods and offers a more cost effective alternative to the traditional mark-recapture models. However, there has been no empirical comparison of the demographic parameters obtained from the two modelling techniques. This study used photographs of natural markings to individually identify wobbegong sharks (Orectolobus maculatus) sighted during underwater surveys over a 2 year period, during eight distinct sampling periods, and analysed with Pollock’s robust design mark-recapture models. These estimates were then compared, using z tests, with Poisson-lognormal mark-resight models that used resightings of sharks previously tagged with telemetry transmitters, and the telemetry data to calculate the number of marked animals present in each sampling period. Sharks were categorised into four groups according to their sex and age-class (adult/juvenile). The results indicated that there was a high degree of transience in the population, with 62 % of sharks only being sighted in one sampling period. Based on normalized Akaike weights, there was no single ‘best’ model for either type of modelling technique and model averaging was used to determine the demographic estimates. Both models showed higher abundance of wobbegongs in the austral spring and summer seasons, however, the models produced statistically different results for five of the eight sampling periods. The mark-recapture model estimated apparent survival between 78 and 95 %, whereas the mark-resight models estimated it between 48 and 97 %. Crucially, there was no statistical difference between the survival estimates from corresponding sex/age-class. The temporary emigration parameters differed substantially between the model types. The mark-recapture model showed support for Markovian movement, whereas the mark-resight supported random emigration. The timing of the tagging events likely biased the abundance and temporary emigration parameters estimated by mark-resight models and must be taken into consideration when designing a mark-resight study. Despite this, this study shows that robust demographic estimates, that are comparable to labour intensive mark-recapture estimates, can still be obtained using mark-resight methods. Given the substantial increase in biotelemetry studies of medium and large sized vertebrates, mark-resight models may play an important future role in estimating demographic parameters.