posted on 2021-03-11, 07:41authored byMattia Falaschi
<p>Measuring the abundance of organisms is essential to
provide information to ecology and biodiversity conservation. Hardly ever, the
probability of detecting an animal during a survey is near one. Overlooking
this observational process can lead to biased estimates of population size and
vital rates. In this study, through Bayesian modeling, I evaluated the effects
of temperature, precipitation, wind, humidity, and phenology in determining
changes in the detection probability of the common wall lizard, for which
studies on the factors determining detection probability are currently not
available. Additionally, I tested for two possible interactions: date-temperature
and date-humidity, in order to assess if the relationships of these variables
with detection probability vary through the sampling season. Detection
probability was highest earlier in the season (April) and between 24 and 28
degrees. Rainfall during the survey showed a negative effect on detection
probability. In contrast, cumulative precipitation in the 24 hours before the
survey showed a positive relationship, indicating that lizards are easier to
detect in surveys after rainy days. Furthermore, date and temperature showed a
positive interaction, indicating that the relationship between detectability
and temperature changed over the sampling season. Date and humidity showed a
negative interaction: late in the sampling season, detectability was higher
with lower humidity, however, this relationship was not found in the early
season. Future studies can consider multiple sites to evaluate the extent of
variation in the drivers of detection probability and to assess the factors
related to abundance.</p>