Population dynamics of an endangered forest bird using mark-recapture models based on DNA-tagging

BAÑUELOS MARÍA JOSÉ; BLANCO-FONTAO BEATRIZ; FAMELI ALBERTO; FERNÁNDEZ GIL ALBERTO; MIROL, PATRICIA MONICA; MORÁN- LUIS MARÍA; R RODRIGUEZ MUÑOZ; QUEVEDO MARIO

CONSERVATION GENETICS

SPRINGER

Lugar: Berlin; Año: 2019 vol. 20 p. 1251 - 1263

1566-0621

Populations of vertebrates are built of individuals of different sexes, age classes orstages, which often affect distinctly the population dynamics. Such Intrapopulationpartitioning of vital rates needs to be identified because conservation actions directedtowards an average population trait may not be adequate. Using DNA extracted fromfeces and feathers we combined DNA-tagging and capture-recapture analyses toevaluate sex-specific demographic parameters of an endangered population ofcapercaillie (Tetrao urogallus; Phasianidae). We built encounter histories for 120individuals between the mating seasons of 2009 and 2011, in a study area of about424 km². Minimum number of individuals per mating season ranged 56 to 67.Estimates of seasonal abundance ranged 76 to 115, translating into very lowpopulation densities < 0.50 birds·km². The superpopulation size was 149 individuals.The sex ratio of identified birds was unexpectedly skewed towards males. Singleseason estimates of population size yielded larger, more variable estimates thanmultiple season estimates. Apparent survival (φ), which likely included some yearlings,was much lower for females; between 2 and 15% lower than expected based on othercapercaillie populations. Male survival was similar to published values. Probability ofrecapture between mating seasons (p) ranged 0.62 to 0.70 and was similar for malesand females. The probability of entering the sampled population (β) was higher forfemales. Realized population growth rate (ʎ) was > 1 for both females and males.Male-biased sex ratios, much lower female survival, and faster turnover of femaleswere the salient demographic results of our study. Although laboratory-intensive, thecombination of DNA tagging based on shed tissues and the theoretical framework ofcapture-recapture models provided inferences on population dynamics that couldhardly be obtained by more intrusive methods.