TY  - JOUR
A1  - Milinkovitch, Michel C.
A1  - Kanitz, Ricardo
A1  - Tiedemann, Ralph
A1  - Tapia, Washington
A1  - Llerena, Fausto
A1  - Caccone, Adalgisa
A1  - Gibbs, James P.
A1  - Powell, Jeffrey R.
T1  - Recovery of a nearly extinct Galapagos tortoise despite minimal genetic variation
JF  - Evolutionary applications
N2  - A species of Galapagos tortoise endemic to Espanola Island was reduced to just 12 females and three males that have been bred in captivity since 1971 and have produced over 1700 offspring now repatriated to the island. Our molecular genetic analyses of juveniles repatriated to and surviving on the island indicate that none of the tortoises sampled in 1994 had hatched on the island versus 3% in 2004 and 24% in 2007, which demonstrates substantial and increasing reproduction in situ once again. This recovery occurred despite the parental population having an estimated effective population size <8 due to a combination of unequal reproductive success of the breeders and nonrandom mating in captivity. These results provide guidelines for adapting breeding regimes in the parental captive population and decreasing inbreeding in the repatriated population. Using simple morphological data scored on the sampled animals, we also show that a strongly heterogeneous distribution of tortoise sizes on Espanola Island observed today is due to a large variance in the number of animals included in yearly repatriation events performed in the last 40years. Our study reveals that, at least in the short run, some endangered species can recover dramatically despite a lack of genetic variation and irregular repatriation efforts.
KW  - captive populations
KW  - conservation biology
KW  - conservation genetics
Y1  - 2013
U6  - https://doi.org/10.1111/eva.12014
SN  - 1752-4571
VL  - 6
IS  - 2
SP  - 377
EP  - 383
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Pagel, Jörn
A1  - Anderson, Barbara J.
A1  - Cramer, Wolfgang
A1  - Fox, Richard
A1  - Jeltsch, Florian
A1  - Roy, David B.
A1  - Thomas, Chris D.
A1  - Schurr, Frank Martin
T1  - Quantifying range-wide variation in population trends from local abundance surveys and widespread opportunistic occurrence records
JF  - Methods in ecology and evolution : an official journal of the British Ecological Society
N2  - 2. We present a hierarchical model that integrates observations from multiple sources to estimate spatio-temporal abundance trends. The model links annual population densities on a spatial grid to both long-term count data and to opportunistic occurrence records from a citizen science programme. Specific observation models for both data types explicitly account for differences in data structure and quality.
 3. We test this novel method in a virtual study with simulated data and apply it to the estimation of abundance dynamics across the range of a butterfly species (Pyronia tithonus) in Great Britain between 1985 and 2004. The application to simulated and real data demonstrates how the hierarchical model structure accommodates various sources of uncertainty which occur at different stages of the link between observational data and the modelled abundance, thereby it accounts for these uncertainties in the inference of abundance variations.
 4. We show that by using hierarchical observation models that integrate different types of commonly available data sources, we can improve the estimates of variation in species abundances across space and time. This will improve our ability to detect regional trends and can also enhance the empirical basis for understanding range dynamics.
KW  - atlas data
KW  - Bayesian statistics
KW  - biogeography
KW  - butterflies
KW  - citizen science programme
KW  - conservation biology
KW  - count data
KW  - macroecology
KW  - state-space model
Y1  - 2014
U6  - https://doi.org/10.1111/2041-210X.12221
SN  - 2041-210X
SN  - 2041-2096
VL  - 5
IS  - 8
SP  - 751
EP  - 760
PB  - Wiley-Blackwell
CY  - Hoboken
ER  -