Bertalanffy-Pütter models for avian growth

Abstract

This paper explores the ratio of the mass in the inflection point over asymptotic mass for 81 nestlings of blue tits and great tits from an urban parkland in Warsaw, Poland (growth data from literature). We computed the ratios using the Bertalanffy-Pütter model, because this model was more flexible with respect to the ratios than the traditional models. For them, there were a-priori restrictions on the possible range of the ratios. (Further, as the Bertalanffy-Pütter model generalizes the traditional models, its fit to the data was necessarily better.) For six birds there was no inflection point (we set the ratio to 0), for 19 birds the ratio was between 0 and 0.368 (lowest ratio attainable for the Richards model), for 48 birds it was above 0.5 (fixed ratio of logistic growth), and for the remaining eight birds it was in between; the maximal observed ratio was 0.835. With these ratios we were able to detect small variations in avian growth due to slight differences in the environment: Our results indicate that blue tits grew more slowly (had a lower ratio) in the presence of light pollution and modified impervious substrate, a finding that would not have been possible had we used traditional growth curve analysis.

Effect of different substrates on growth and biochemical composition of the ornamental “red cherry” caridean shrimp, Neocaridina davidi (Atyidae)

“…davidi were compared among different substrates using sigmoid growth functions. These models have become popular in recent decades and have been successfully applied to other crustacean species (Aragón‐Noriega, 2017), ophiuroidea (Stratanenko & Denisenko, 2020), fish (Hart & Chute, 2009; Kielbassa et al, 2010; Wang & Ma, 2016), birds (Brunner et al, 2021; Svagelj et al, 2019), mammals (Thorley & Clutton‐Brock, 2019) and even in plants (Ukalska & Jastrzębowski, 2019). Here, it was found that N .…”

Parameter estimation of the Solow–Swan fundamental differential equation

“…For example, in a study of nestlings of blue tits from an urban park, each bird had its own optimal exponent (pair) that was unrelated to the metabolic exponents proposed by Bertalanffy and West. Rather, the model parameters were associated to small variations in the environment around each nest site ( Brunner et al., 2021 ), whence the exponents were no longer interpreted in terms of metabolism. Instead, they were related to the shape of the size-at-age data (specifically to the ratio of the size at fastest growth over adult size).…”