31 research outputs found
The importance of including phenology when modelling species ecological niche
Species distribution models have grown in complexity by incorporating fine-scale variables, including data on microclimate, physiology and species interactions. Recent studies have acknowledged the importance of the spatial scale by including higher resolution maps and more complex climatic variables. However, models rarely consider the consequences of including data related to time. Indeed, species phenology - and potential shifts in phenology due, for example, to climate change - is potentially one of the most neglected aspects of ecological modelling. We present a literature review of relevant phenological aspects at different temporal scales and across several taxa. Such elements should be considered to define better the environmental niche and project present, future and past distribution models. We considered the available studies on plants, insects, reptiles, birds and mammals to evaluate how they dealt with the phenology of the investigated species, as well as the phenology of other resources and interacting species, to infer present, past and future projections. Here we focus on four main phenological aspects that, if not considered, may easily bias any projection, namely: 1) phenology can be accompanied by a shift in distribution within the year (e.g. migratory species); 2) activity may be restricted to a portion of the year (e.g. most ectotherms from temperate climates); 3) survival and reproduction success may depend on the synchrony with other species phenology (e.g. plants-pollinators interactions); 4) changes in climatic conditions can lead to shifts in phenology (e.g. anticipated or delayed blooms or changes in migration timing). In this review, we show how neglecting such factors may quickly lead to project a biased distribution. Finally, we provide a guide on evaluating whether the case study may be affected by such factors and what actions may improve the models.RP was supported by the Basque Government Department of Education (POS_2020_1_0009). MS was supported by the Spanish Ministry of Research and Innovation (FJC2019-040170-I)
Stable or plastic body shape? Emys orbicularis hatchlings-juveniles growth patterns under different ecological conditions
To test if habitat could shape shell features of freshwater turtles starting from birth, we tested hatchlings of Emys orbicularis, randomly chosen from four clutches of the same locality, under two treatments, stagnant (pond habitat) vs lotic (river habitat) water regimes. Due to mortality at the beginning of the experiment, we finally considered only two clutches. Turtle shells were characterized initially at hatching and then after one year of treatment by means of traditional and geometric morphometrics, and phenotypic trajectories analyses were conducted on both types of data. Carapace growth was isometric both in proportion and shape, while plastron showed an allometric pattern: length increased more than width, while the contour showed an expansion at the rear and a compression of the front. The hydrodynamic conditions during growth did not seem to affect the phenotypic trajectories of the shell proportions or the plastron. On the contrary, a significant effect was found on the phenotypic trajectory of the carapace: the size component (but not the angle one) was positively influenced by the "lentic" treatment, suggesting a different growth rate between the two environmental conditions
Stable or plastic body shape? Emys orbicularis hatchlings-juveniles growth patterns under different ecological conditions.
To test if habitat could shape shell features of freshwater turtles starting from birth, we tested hatchlings of Emys orbicularis, randomly chosen from four clutches of the same locality, under two treatments, firm (pond habitat) vs running (river habitat) water regimes. Due to mortality at the beginning of the experiment, we finally considered only two clutches. Turtle shells were characterized at hatch and after one year of treatment by means of traditional and geometric morphometrics and phenotypic trajectories analysis were conducted on both types of data. Carapace growth was isometric both in proportion and shape, while plastron showed an allometric pattern: length increased more than width while the contour showed an expansion of the rear part and a compression of the front one. The hydrodynamic conditions during growth did not seem to affect the phenotypic trajectories of shell proportions nor those of plastron. On the contrary a significant effect was found on the phenotypic trajectory of carapace: the size component (but not the angle one) was positively influenced by the “pond” treatment, suggesting a different growth rate between the two environmental conditions. Hypotheses on possible ecological constraints derived from habitat conditions are presented and discussed
Photo-identification in amphibian studies: a test of I3S Pattern
Photo-identification is used for individual recognition of several animal species. It gives the possibility to take photos of large species from a distance or to avoid invasive marking techniques in small animals. For amphibians, the use of non-invasive marking methods is even more relevant in the light of their global decline. Here we use the photo-identification data from a population of Triturus carnifex to validate the photo-identification software I3S Pattern. This recently developed utility has never been applied to amphibians. The software proved to be efficient and accurate for individual recognition for this species. Contrarily to the previous releases of the I3S family, I3S Pattern is particularly suitable for amphibians characterized by a complex individual pattern of large blotches or irregular spots, which are not readily identified by eye
Reptiles under the sun: using lacertid lizards to study thermal and water ecology in ectotherms
The importance of including phenology when modelling species ecological niche
Species distribution models have grown in complexity by incorporating fine-scale variables, including data on microclimate, physiology and species interactions. Recent studies have acknowledged the importance of the spatial scale by includ-ing higher resolution maps and more complex climatic variables. However, models rarely consider the consequences of including data related to time. Indeed, species phenology – and potential shifts in phenology due, for example, to climate change – is potentially one of the most neglected aspects of ecological modelling. We pres Species distribution models have grown in complexity by incorporating fine-scale variables, including data on microclimate, physiology and species interactions. Recent studies have acknowledged the importance of the spatial scale by includ-ing higher resolution maps and more complex climatic variables. However, models rarely consider the consequences of including data related to time. Indeed, species phenology – and potential shifts in phenology due, for example, to climate change – is potentially one of the most neglected aspects of ecological modelling. We pres-ent a literature review of relevant phenological aspects at different temporal scales and across several taxa. Such elements should be considered to define better the environmental niche and project present, future and past distribution models. We considered the available studies on plants, insects, reptiles, birds and mammals to evaluate how they dealt with the phenology of the investigated species, as well as the phenology of other resources and interacting species, to infer present, past and future projections. Here we focus on four main phenological aspects that, if not considered, may easily bias any projection, namely: 1) phenology can be accompa-nied by a shift in distribution within the year (e.g. migratory species); 2) activity may be restricted to a portion of the year (e.g. most ectotherms from temperate climates); 3) survival and reproduction success may depend on the synchrony with other species phenology (e.g. plants–pollinators interactions); 4) changes in climatic conditions can lead to shifts in phenology (e.g. anticipated or delayed blooms or changes in migration timing). In this review, we show how neglecting such factors may quickly lead to project a biased distribution. Finally, we provide a guide on evaluating whether the case study may be affected by such factors and what actions may improve the models.RP was supported by the Basque Government Department of Education (POS_2020_1_0009). MS was supported by the Spanish Ministry of Research and Innovation (FJC2019-040170-I).Peer reviewe
Dehydration constrains thermoregulation and space use in lizards.
Climate change is negatively affecting many species. The increase in mean air temperature is often associated with shifts in distribution, changes in phenology, and local extinctions. Other factors that only partially correlate with air temperature, like water shortage, may also contribute to the negative consequences of climate change. Although the effect of temperature on lizards' ecophysiology is highly studied, many lizards are also at risks of increased water loss and dehydration, which are predicted to increase under climate change. Here we aimed for the first time to explore if lacertid lizards exposed to dehydration thermoregulate less precisely than hydrated lizards and if dehydrated lizards are less active, change the daily pattern of thermoregulation and balance water balance against thermoregulation. We exposed four lizard species with differences in the thermal preference to thermal gradients with or without a source of water. We measured preferred body temperatures, daily pattern of thermoregulation, and the use of space. Dehydration negatively affected thermoregulation in all investigated species. Dehydrated lizards reduced their preferred body temperature and showed a species-specific pattern of hourly change in thermal preference. Furthermore, they more frequently used the colder parts of the gradients and spent more time hidden. Lizards experiencing dehydration may suffer a reduction in survival and fitness because of poor thermoregulation. Similarly, they may spend more time hidden, waiting for more favourable weather conditions. Such inactivity may carry ecological costs especially in those regions that undergo either short or prolonged periods of droughts
Photo-identification in amphibian studies: A test of I3S Pattern
Photo-identification is used for individual recognition of several animal species. It gives the possibility to take photos of large species from a distance or to avoid invasive marking techniques in small animals. For amphibians , the use of non-invasive marking methods is even more relevant in the light of their global decline. Here we use the photo-identification data from a population of Triturus carnifex to validate the photo-identification software I 3 S Pattern. This recently developed utility has never been applied to amphibians. The software proved to be efficient and accurate for individual recognition for this species. Contrarily to the previous releases of the I 3 S family, I 3 S Pattern is particularly suitable for amphibians characterized by a complex individual pattern of large blotches or irregular spots, which are not readily identified by eye
Head shape variation in eastern and western Montpellier snakes
The Montpellier snake Malpolon monspessulanus is a wide-ranging species that inhabits Western and Eastern Europe, North Africa and Middle East. Four clades have been recognised as two species, M. insignitus and M. monspessulanus, each with two subspecies. Clades have been substantially identified on the basis of molecular data, pholidosis and colouration, while morphometric traits have been ignored. We compared head shape of 54 specimens belonging to three out of the four clades (M. insignitus insignitus, M. i. fuscus, and M. monspessulanus monspessulanus) by means of geometric morphometrics. We found a significant differentiation: the supraocular and frontal area showed the largest amount of variation, being respectively much thinner in M. i. insignitus, a bit less thin in M. i. fuscus and definitely wider in M. m. monspessulanus. Our findings are fully in agreement with the genetic studies and phylogeny explains more than 20% of the observed variation, supporting the taxonomic distinction inside the genus Malpolon. The functional and/or adaptive meaning of the observed differences is not clear, but it seems unlikely that it may be related to diet. Combining morphological data with phylogeography and environmental features, we formulated an explanatory hypothesis that allowed a precise and testable prediction
Un nuovo tipo di trappola per tritone punteggiato (Lissotriton vulgaris) e tritone crestato (Triturus carnifex)
Durante il periodo riproduttivo, gli anfibi si spostano verso i bacini in cui avverranno gli accoppiamenti. Nella maggior parte degli studi focalizzati sui tritoni è necessario catturare un numero variabile di individui, al fine di stimare la consistenza numerica della popolazione riproduttiva, la fenologia oppure raccogliere campioni biologici e dati biometrici. In tutti questi studi la cattura deve essere contemporaneamente efficiente e il meno invasiva possibile, compatibilmente con il tipo di sito riproduttivo. Metodi di campionamento largamente utilizzati prevedono l'uso di retini, bottiglie tagliate a formare piccole nasse, reti da pesca e nasse per gamberi.
Nell'ambito di un progetto volto alla valutazione demografica di una popolazione di tritone punteggiato e tritone crestato in uno stagno nel Parco Regionale delle Groane, abbiamo ideato e costruito una trappola appositamente concepita per il sito studiato. Si tratta di una nassa cilindrica con aperture a imbuto disposte a spirale lungo l'asse principale. La struttura è realizzata in rete da giardino cucita con fil di ferro. Il diametro delle maglie della rete è di circa 3 mm. La nassa può essere posizionata sia in verticale, sia in orizzontale, mantenendo sempre una porzione galleggiante, grazie al polistirolo inserito all'interno. Durante due mesi di campionamento sono stati catturati oltre quattrocento tritoni, molti dei quali ricatturati più volte. Nonostante l'alta naturalità del sito, nella trappola, oltre ai tritoni, sono state catturate solo alcune rane verdi, qualche girino di rana rossa e alcuni ditischi.
La nassa da noi ideata si presenta quindi come uno strumento economico, leggero, di facile costruzione, efficiente nel campionamento dei tritoni e, al contempo, selettivo nei confronti delle altre specie palustri. Inoltre, essendo uno strumento non invasivo, può essere usata anche in ambienti ad elevata naturalità, laddove la protezione dell'ecosistema palustre è di primaria importanza