Between 2010 and 2011, an arterial road was constructed within provincially significant wetlands in the South March Highlands (SMH) located in Ottawa, Ontario, Canada. The wetlands and adjacent upland areas were determined to be sensitive habitat for Blanding's Turtles (Emydoidea blandingii (Holbrook, 1838)) during the approval and permitting process, and a population study was required as part of the road construction project. The study consisted of a 4-year mark-recapture program and a movement study of radio-tagged adult turtles. General findings included the identification of 27 adult males and 55 females and a population estimate of 93 adults (95% Cl: 86-118). A 1:2.32 male to female sex bias was also found. Mean home-range size was 19.06 ha and tagged turtles moved, on average, more per observation in 2013 (191.40 m compared with 89.75 and 123.04 m in 2011 and 2012, respectively). Previously reported differences in movement patterns between males, females, and gravid females were not observed. The SMH Blanding's Turtle population should be closely monitored because urban development continues in the area, which may further reduce the population size. Understanding the biology of imperiled populations across species' ranges is necessary to promote conservation and adaptive wildlife management. Key words: POPAN formulation, home range, radiotelemetry, urban development, population estimate, freshwater turtles. En 2010-2011, une voie arterielle a ete construite dans des zones humides d'importance provinciale dans les hautes terres de South March (SMH), situees a Ottawa (Ontario, Canada). Durant le processus d'approbation et d'obtention de permis, il a ete etabli que ces zones humides et les hautes terres attenantes sont des habitats sensibles pour les tortues mouchetees (Emydoidea blandingii (Holbrook, 1838)), et une etude de la population a ete exigee dans le cadre du projet de construction routiere. L'etude consistait en une campagne de marquage-recapture de 4 ans et une etude des deplacements de tortues adultes munies de radio-emetteurs. Les constatations generales comprennent l'identification de 27 males adultes et 55 femelles et une estimation de la population a 93 adultes (IC a 95%: 86-118). Un rapport males-femelles de 1:2,32 a egalement ete observe. La taille moyenne du domaine vital etait de 19,06 ha et les tortues munies de radio-emetteurs se deplacaient en moyenne plus a chaque observation en 2013 (191,40 m, comparativement a 89,75 et 123,04 m, respectivement, en 2011 et 2012). Des differences deja signalees entre les habitudes de deplacement des males, des femelles et des femelles gravides n'ont pas ete observees. La population de tortues mouchetees des SMH devrait faire l'objet d'une surveillance etroite au fil du developpement urbain dans cette zone, qui pourrait reduire encore davantage la taille de la population. La comprehension de la biologie de populations en peril dans les aires de repartition des especes est necessaire a la promotion de la conservation et d'un amenagement faunique adaptatif. [Traduit par la Redaction] Mots-cles: formulation POPAN, domaine vital, radiotelemetrie, developpement urbain, estimation de population, tortues d'eau douce., Introduction Understanding the unique characteristics of different populations of endangered species aids in conservation and protection (Crandall et al. 2000), especially in support of adaptive management by stakeholders (Fontaine 2011) [...]