Carcharias taurus is listed as Critically Endangered along the east coast of Australia and there is concern about their status globally. The use of traditional tag–recapture methods to monitor the east coast C. taurus population have been discontinued due to tag–biofouling and injuries that relate to tag attachment. In the current study, captive and wild C. taurus were used to assess whether spots present on their flanks were suitable natural tags for individual shark recognition. Photographic images of seven captive sharks taken at monthly intervals for 13 months and at three years after the start of the study indicated that their spot number, position and relative size did not change over this period. Similarly, eighty–nine wild sharks photographically re–identified at least 23 months after their initial identification (and in one case after 14 years) confirmed long–term spot–pattern retention. Photographic recaptures of individual C. taurus provided information about their temporal and spatial distribution and movement patterns along the Australian east coast in relation to maturity, sex and reproductive condition. A total of 930 sharks were photo–identified between 2004 and 2008 at 23 aggregation sites between Wolf Rock and Montague Island. Of these, 479 were females (271 mature, 208 immature) and 452 were males (288 mature, 60 sub–adults, 104 juveniles). The distribution of pregnant C. taurus was seasonally and temporally distinct from all other sharks. Visibly pregnant C. taurus were recorded at Wolf Rock (the most northern site) from February until October, although many sharks left during July. Pregnant C. taurus were also observed at North Moreton Island, Flat Rock and Fish Rock between June and November. Resting (mature, non–gravid) females and mature males were mostly observed at mid–southern sites from December to June, with northern counts increasing from June to November. The majority of immature sharks were recorded at mid–southern sites. Of 930 sharks identified between 2004 and 2008, 149 were identified at more than one site. On average, mature females moved 338 km (SD ± 465), mature males 340 km (SD ± 299), immature females 147 km (SD ± 98), sub–adult males 185 km (SD ± 216), and juvenile males 271 km (SD ± 237). The maximum rate of movement per day was 18.5 km for a mature female shark, 20.7 km for a mature male, 4.3 km for an immature female, 86 km for a sub–adult male and 4 km for a juvenile male. Mature males and mature non–pregnant females tended to move north from mid–winter and mate in late spring/early summer in warmer waters. From about mid–winter, pregnant females began to move from the warmer waters of their gestation areas to cooler southern waters to pup (probably from late spring to mid–summer). The movement patterns of immature sharks varied temporally, and were more limited spatially. Underwater censuses, photo–identification and acoustic tracking of individual C. taurus were used to investigate their reproductive periodicity, localised movements and behavioural segregation at Wolf Rock – the most northerly aggregation site on the east Australian seaboard. A biennial reproductive cycle was indicated for 18 of 28 females for which re–identifications spanned at least two mating and/or pregnancy events. Nine of the 28 sharks appeared to exhibit a triennial reproductive cycle. Male C. taurus were observed between July and January, but were absent between February and April. Scuba divers reported seeing some mating scars on individuals from mid–October, however fresh mating scars were predominately observed on photographs of individual C. taurus taken in November and December. Four acoustically–tagged mature female sharks remained within 500 m of the Wolf Rock aggregation site within a marine sanctuary zone for 78 – 90 % of the 11–15 day study period. A minimum population estimate of 930 individuals is provided from all sharks identified between 2004 and 2008. In addition, a Jolly–Seber (open model design) mark–recapture analysis on data obtained during four scheduled photo–identification surveys (conducted between July 2006 and February 2008 at 25 aggregation sites along the east coast of Australia) was used to estimate the size of this population. A maximum of 272 sharks (143 females and 129 males) were identified during any scheduled survey period. Model averaging across the highest rated JS models (Popan data formulation) resulted in an estimate of 756 males (95% CI = 590 – 922) and 1185 females (95% CI = 901 – 1469). The mark–recapture abundance estimate is considered preliminary and requires further model development to incorporate the heterogeneity in distribution and migration patterns within the C. taurus population. The occurrence of retained fishing gear and gear–related jaw injuries were quantified from the four scheduled photo–identification surveys along the east coast of Australia. A total of 673 sharks were identified with 119 occurrences of retained fishing gear or jaw injury recorded from 113 individual sharks. For sharks that were known by spot–patterns on both flanks, 29 % of females and 52 % of males were seen with retained fishing gear or a gear–related jaw injury. The largest numbers of identified sharks (222) during the surveys were seen at Fish Rock (off the New South Wales coast): 48 % of all sharks identified with retained fishing gear were first identified at this site. Fish Rock is a designated critical habitat for C. taurus, but most forms of line fishing, except fishing while anchored or moored with bait and/or wire trace line are permitted. Results from the surveys clearly demonstrated that C. taurus is susceptible to a large variety of fishing gear and fishing methods. Current protection measures for C. taurus appear insufficient at this site, particularly as large aggregations that include immature and mature sharks occur consistently throughout the year.

Developing appropriate management plans for species at risk requires information about their population structure and abundance. For most cetacean populations, few reliable population estimates are available and even fewer distributions have been mapped. Accurate abundance estimates can be determined from capture-recapture data if assumptions are met, however this can be difficult when the animal in question demonstrates both strong site fidelity and large-scale migrations, and different models can result in dramatically different results. I explored these issues by examining a 15-year dataset (1992-2006) of photo-identifications of humpback whales (Megaptera novaeangliae) in British Columbia (BC), Canada. I used multiple capture-recapture models to compare how the definition of population and variation in effort affected estimates of population size, and I explored means to correct for these biases. I also considered stock structure by examining individual breeding ground destinations, movement, and localized site-fidelity within BC. Across the six models considered, the BC humpback whale abundance in 2006 ranged between 1,428 and 3,856 individuals. The Lincoln-Petersen estimate (1,428-1,892) likely best described the number of humpback whales in BC during summer 2006. The effort-standardized Jolly-Seber model (1,970-2,331) is more representative of the larger population of humpback whales that uses or passes through BC over multiple years. Ultimately, selecting the best estimation model requires defining the ‘population’ of interest and accounting for spatial and temporal distribution of sampling effort. British Columbia provides feeding habitat and a potential migratory corridor for whales that breed in the northeastern Pacific Ocean. Forty-four percent of the 1,986 humpback whales considered were sighted in BC in more than one year. Identifications were highest from May to October, with a peak in September, but humpback whales were present in BC in all months of the year. Whales showed strong site fidelity with a median re-sighting distance of 75 km between years, and a maximum re-sighting distance that ranged from 0.41 km to 842 km. Matching rate within BC decreased as a function of north-south distance, though no clear north-south boundary could be established. Stock structure of humpback whales in British Columbia is complex and should be considered in managing this population.

Habitat degradation by humans has been the main reason for the decline in numbers of P. floridanus, the only mammal indigenous to the state of Florida, in the past century. The mouse inhabits what remains of scrub and sandhill associations, which are characterized by patches of sandy soils within a more mesic landscape. It has long been accepted that small populations are more prone to decline and extinction than are larger ones as a result of environmental fluctuations. I hypothesized that the demography of a population of P. floridanus would be affected by a restriction in numbers through habitat patch size in a deterministic way, even without any environmental effects. I also examined dispersal and looked for evidence of metapopulation dynamics. Mark-recapture data were collected from ten scrub fragments in Lake Wales Ridge State Forest, Polk County, FL, ranging in size from 0.5 to 170 ha. Program MARK was used to model survival, recruitment and population growth rate of P. floridanus as a function of habitat patch size and to evaluate temporary migration patterns. Recruitment was positively associated with patch size, but contrary to expectations survival and population growth were negatively associated with patch size. Results suggested that survival was negatively affected by ear tagging, although this effect was temporary. Evidence of migration was found, but would probably have been greater if trapping had been continued until after peak reproduction, when juveniles tend to disperse in search of resources. The degree of interbreeding among patches can only be determined with the help of genetic analyses. Microsatellites have become useful in analyses at the population level because of their high degree of variability. Future research including genetic analyses is recommended to evaluate the importance of gene flow among subgroups to demography and the viability of the study population.

The Jollyville Plateau Salamander (JPS), Eurycea tonkawae, is a species of salamander endemic to Texas, the United States. It is a candidate for protection under the Endangered Species Act. This report assesses the JPS population abundances at Lanier Spring, Long Hollow Creek at Wheless Spring, and Ribelin Spring in Austin using a mark-recapture method. The maximum likelihood estimation method was used to obtain the population size estimates under two models, the M₀ model and the M[subscript t] model. The M₀ model assumes that every animal has the same capture probability in the population for each sampling period while the M[subscript t] model allows capture probabilities to vary by time. Simulations were performed by using an MCMC algorithm based on the M₀ model. Between 2007 and 2009, the population size estimates for JPS (>16mm snout-vent length, (SVL)) at Lanier Spring varied between 86 and 554 under the M₀ model, between 80 and 549 under the M[subscript t] model, and between 76 and 564 using MCMC simulations. During 2007 monitoring periods, the population size estimates for JPS (>16mm SVL) at Ribelin Spring varied between 105 and 236 under the M₀ model, between 104 and 196 under the M[subscript t] model, and between 105 and 265 using MCMC simulations. During 2007 and 2008 monitoring periods, the population size estimates for JPS (>16mm SVL) at Wheless Spring varied between 368 and 1087 under the M₀ model, between 339 and 1075 under the M[subscript t] model, and between 411 and 1098 using MCMC simulations. Different estimation methods yielded consistent estimates. No clear population trends were detected due to the big fluctuations in estimates in this study. / text

Nicrophorus americanus is a federally endangered species whose range has decreased dramatically since the 1920s. It is a nocturnal species that is only active from May to September when temperatures reach at least 15.5°C for three nights in a row. It once ranged throughout North America, from Maine and the southern parts of Canada, west to South Dakota and south to Texas. The historic Texas population consists of four Texas specimens from the 1880s residing at the Philadelphia Academy of Science Invertebrate Collection. Since then, there were no confirmed specimens in Texas, until 2003 when a single individual was found in Lamar County, Texas. The population discovered in Lamar County has been on a steady decrease from 2005, 223 individuals captured, until 2008 only 8 individuals captured. Since 2008, no individuals have been captured in Texas, despite intense surveys. It is possible that the Texas population is a sink population with the Oklahoma population to its north, acting as the source. Genetic analysis of the Texas and Oklahoma populations would help to answer this question and analysis of the entire population may answer questions to why the species declined leaving only the peripheral populations. The specific habitat variables that caused the population to re-colonize and go extinct in Texas are unclear, but when determined could play a critical role in managing the population. / text

Developing appropriate management plans for species at risk requires information about their population structure and abundance. For most cetacean populations, few reliable population estimates are available and even fewer distributions have been mapped. Accurate abundance estimates can be determined from capture-recapture data if assumptions are met, however this can be difficult when the animal in question demonstrates both strong site fidelity and large-scale migrations, and different models can result in dramatically different results. I explored these issues by examining a 15-year dataset (1992-2006) of photo-identifications of humpback whales (Megaptera novaeangliae) in British Columbia (BC), Canada. I used multiple capture-recapture models to compare how the definition of population and variation in effort affected estimates of population size, and I explored means to correct for these biases. I also considered stock structure by examining individual breeding ground destinations, movement, and localized site-fidelity within BC. Across the six models considered, the BC humpback whale abundance in 2006 ranged between 1,428 and 3,856 individuals. The Lincoln-Petersen estimate (1,428-1,892) likely best described the number of humpback whales in BC during summer 2006. The effort-standardized Jolly-Seber model (1,970-2,331) is more representative of the larger population of humpback whales that uses or passes through BC over multiple years. Ultimately, selecting the best estimation model requires defining the ‘population’ of interest and accounting for spatial and temporal distribution of sampling effort. British Columbia provides feeding habitat and a potential migratory corridor for whales that breed in the northeastern Pacific Ocean. Forty-four percent of the 1,986 humpback whales considered were sighted in BC in more than one year. Identifications were highest from May to October, with a peak in September, but humpback whales were present in BC in all months of the year. Whales showed strong site fidelity with a median re-sighting distance of 75 km between years, and a maximum re-sighting distance that ranged from 0.41 km to 842 km. Matching rate within BC decreased as a function of north-south distance, though no clear north-south boundary could be established. Stock structure of humpback whales in British Columbia is complex and should be considered in managing this population.

This study looked at the efficacy of using woodland caribou fecal pellets as a source of DNA to identify sampled animals and estimate population demographics. Fecal pellet samples were collected using systematic surveys of woodland caribou ranges in Jasper National Park, Alberta and the North Interlake region, Manitoba. Collection of pellet samples took place when snow was present to allow for tracking and location of caribou cratering areas and to obtain good quality DNA. DNA was amplified at ten polymorphic loci and one sex-specific primer. To estimate population size (N ̂) and population growth rate (λ), mark-recapture models were used. Model assumptions were evaluated and tested by stratifying available samples based on herd and gender information. In using the Mh (jackknife) model, the population sizes for south Jasper National Park were estimated at 125 animals in 2006-2007 (95% CI: 114, 143), 91 animals in 2007-2008 (95% CI: 83, 105) and 134 animals in 2008-2009 (95% CI: 123, 152); comparable to the mark-resight population estimates calculated over the same sampling periods. Genetic diversity indices for the different herds in Jasper National Park presented a lower genetic diversity for the smaller Maligne and Brazeau herds when compared to the larger Tonquin and A La Peche herds. Use of population assignment tests on samples collected in Jasper National Park indicated considerable admixture between the different herds despite earlier telemetry work demonstrating strong herd fidelity. The North Interlake population was estimated at 134 animals (95% CI: 122,151) in 2006-2007 and 106 animals (95% CI: 97, 121) in 2007-2008. Using data collected between 2005 and 2008, population growth rate for North Interlake was estimated at 0.83 (90% confidence interval: 0.65, 1.02). As a λ below 1 indicates a declining population, continue monitoring of the North Interlake herd is highly recommended. This studied clearly showed that the sampling of fecal DNA is a reliable and noninvasive alternative to monitoring woodland caribou population sizes and trends in the boreal and mountain regions.

Several parasites that require two or more hosts to complete their life cycles are known to manipulate host behaviour, enhancing their transmission to the next host. The intertidal snail, Littorina sitkana, is host to a diverse assemblage of parasites dominated by trematodes. Trematodes often use snails as first intermediate host and vertebrates as definitive host. Trematode infections can affect host behaviours such as dispersal and foraging. I identified four sites in Barkley Sound that varied in trematode prevalence and species richness. I measured dispersal of snails at these sites and in the laboratory to assess effects of trematode infection on behaviour. I measured feeding rate under laboratory conditions. Trematode effects lowered snail grazing activity at three of the four sites studied, suggesting trematode infection lowers feeding rate of L. sitkana, potentially affecting algal composition of the intertidal zone. Infected male snails travelled longer distances in some sites but shorter distances in others. There was an almost significant effect of trematode infection on vertical displacement of L. sitkana in the field. I estimated survival rates on each site through intensive capture-mark-recapture experiments. There was differential survival among sites, but no negative correlation between survival estimates and trematode prevalence. / Graduate / 0718 / 0329 / 0472 / mayala@uvic.ca

This study looked at the efficacy of using woodland caribou fecal pellets as a source of DNA to identify sampled animals and estimate population demographics. Fecal pellet samples were collected using systematic surveys of woodland caribou ranges in Jasper National Park, Alberta and the North Interlake region, Manitoba. Collection of pellet samples took place when snow was present to allow for tracking and location of caribou cratering areas and to obtain good quality DNA. DNA was amplified at ten polymorphic loci and one sex-specific primer. To estimate population size (N ̂) and population growth rate (λ), mark-recapture models were used. Model assumptions were evaluated and tested by stratifying available samples based on herd and gender information. In using the Mh (jackknife) model, the population sizes for south Jasper National Park were estimated at 125 animals in 2006-2007 (95% CI: 114, 143), 91 animals in 2007-2008 (95% CI: 83, 105) and 134 animals in 2008-2009 (95% CI: 123, 152); comparable to the mark-resight population estimates calculated over the same sampling periods. Genetic diversity indices for the different herds in Jasper National Park presented a lower genetic diversity for the smaller Maligne and Brazeau herds when compared to the larger Tonquin and A La Peche herds. Use of population assignment tests on samples collected in Jasper National Park indicated considerable admixture between the different herds despite earlier telemetry work demonstrating strong herd fidelity. The North Interlake population was estimated at 134 animals (95% CI: 122,151) in 2006-2007 and 106 animals (95% CI: 97, 121) in 2007-2008. Using data collected between 2005 and 2008, population growth rate for North Interlake was estimated at 0.83 (90% confidence interval: 0.65, 1.02). As a λ below 1 indicates a declining population, continue monitoring of the North Interlake herd is highly recommended. This studied clearly showed that the sampling of fecal DNA is a reliable and noninvasive alternative to monitoring woodland caribou population sizes and trends in the boreal and mountain regions.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Estudos envolvendo estimativas de parâmetros populacionais de cetáceos baseados em dados de foto-identificação têm crescido ao longo dos anos, possibilitando estimar parâmetros como abundância, sobrevivência, probabilidade de captura e padrões de emigração. No Brasil, ainda são poucos os estudos com cetáceos que utilizam essa abordagem, contudo, eles estão aumentando, principalmente com a espécie Sotalia guianensis (van Bénéden, 1864), conhecida como boto-cinza. O objetivo desse trabalho foi estimar a sobrevivência, a probabilidade de captura, a emigração e a abundância da população de botos-cinza na Baía de Paraty (RJ; 2307S 4433W), utilizando modelos de marcação-recaptura baseados em dados de foto-identificação, entre os anos de 2005 e 2009. Os cruzeiros foram realizados entre agosto de 2005 e julho de 2009 com uma embarcação de 26 pés e motor de 200hp. As fotografias das nadadeiras dorsais foram tomadas com a utilização de uma câmera digital Canon 20D equipada com lente de zoom 100-400mm. Foram realizadas 60 saídas de campo na Baía de Paraty totalizando 172 horas de esforço no campo, sendo 72 horas de esforço fotográfico. Nas 42 saídas com observação de botos-cinza foram efetuadas 27.892 fotografias e, destas, 6.612 (23,7%) foram consideradas adequadas e utilizadas na identificação dos indivíduos de boto-cinza. Um total de 621 indivíduos foi catalogado com base em marcas permanentes na nadadeira dorsal. Os históricos individuais de captura foram analisados no programa MARK. A estimativa de sobrevivência variou de 0,82 ( 0,05) a 0,85 ( 0,05) e a probabilidade de captura variou de 0,16 ( 0,04) a 0,40 ( 0,06). O número de indivíduos marcados na população estimado pelo modelo de Jolly-Seber foi de N = 586 ( 114,66) (IC: 361-811). A proporção de animais marcados na população para o modelo de JS foi de 0,66 ( 0,03). A partir desse valor, foi possível obter uma abundância total de 884 indivíduos ( 176,8) (IC: 602-1296). A probabilidade de emigração temporária (γ``) e de permanecer fora da área (γ`) foi de 0,43 ( 0,07) e a probabilidade de captura/recaptura variou de 0,01 ( 0,01) a 0,42 ( 0,05). A probabilidade de permanência na área (1 - γ``), assim como a probabilidade de retorno da emigração temporária (1 - γ`) foi 0,57. Apesar dos movimentos significativos de indivíduos transientes, uma vez que a área amostrada é menor do que as áreas de vida que se tem estimadas para o boto-cinza, os dados indicam uma residência moderada dos botos-cinza. A abundância anual total variou de 325 para o ano de 2005 a 448 para o ano de 2009. A análise de poder determinou que seriam necessários nove anos de estudo para observar uma tendência de queda de 5% no tamanho da população. Os resultados reforçam que a Baía de Paraty abriga uma das maiores populações já estimadas para Sotalia guianensis.