Activity comparison of the common tern (Sterna hirundo) during nesting in freshwater and marine habitats

Crvenokljune čigre (Sterna hirundo) su morske ptice koje se kolonijalno gnijezde na morskim i slatkovodnim staništima. U inkubaciji i podizanju mladunaca sudjeluju oba roditelja. U svrhu istraživanja dinamike ponašanja na gnijezdima crvenokljunih čigri različitih staništa prikupljene su serije fotografija načinjene fotozamkama smještenim na tri kolonije: dvije slatkovodne i jednoj morskoj. Fotografije sa sedam gnijezda sortirane su temeljem stanja SJEDI, PORED i NEMA temeljenih na položaju ptice na gnijezdu. Izračunato je dnevno trajanje svakog stanja, trajanje stanja do promjene i ukupni broja promjena, a analiza je napravljena i za dijelove dana. Analiza je provedena u programskom jeziku R koristeći se neparametrijskim statističkim testovima. Utvrđena je značajnu razlika u vremenu provedenom na gnijezdu među gnijezdima unutar istog, ali i među različitim tipovima staništa. Ptice na gnijezdima slatkovodnih kolonija značajno su više vremena provodile inkubirajući, dok su ptice na morskim kolonijama značajno više vremena bile odsutne, što se povezuje s lakše dostupnim izvorima hrane na slatkovodnim staništima. Predacija, intraspecijsko antagonističko ponašanje, iskustvo jedinki u gniježđenju i meteorološki uvjeti mogući su dodatni utjecaji na vrijeme provedeno u inkubaciji.The common tern (Sterna hirundo), nests colonially on both marine and freshwater habitats with incubation and chick rearing being shared parental responsibilities. In order to research the dynamics of incubation behaviour in this species, series of camera trap photographs taken between May 2021 and May 2023 were collected from three different colonies, one of which was from a marine and the two from freshwater habitats. Photographs of seven nests were sorted into three states (incubating, near nest and not present) for which the state duration per day, the state duration until change and the number of state changes were calculated. The same calculations were repeated for different times of day. Nonparametric statistical tests were conducted using the R programming language. Incubation times differed significantly among nests from the same and different habitats. Individuals on freshwater colonies spent a significantly longer time incubating, while birds from the marine habitat spent a longer time away from nest, both of which can be related to more predictable prey availability at freshwater sites. Predation, conspecific antagonistic behaviour, breeding experience and meteorological conditions are additional factors affecting incubation activity for this species

The polychaete Hermodice carunculata (Pallas, 1776) in the Adriatic Sea

Vatreni crv, Hermodice carunculata (Pallas, 1776) je bentički predatorski mnogočetinaš koji obitava diljem Atlantskog oceana, uključujući i Mediteran. To je vrsta koja je u posljednje vrijeme uspostavila niz novih populacija uz obale Sredozemnog mora pa tako i u Jadranu. Informacije o ovoj vrsti često su manjkave i sporadične, no recentna istraživanja pokazuju jasan trend koloniziranja novih prostora koji, pod pritiskom globalnih promjena ekosustava, postaju sve topliji. Zasad ova vrsta još nije prešla u kategoriju invazivne vrste no definitivno ima potencijal da to postane u budućnosti. Ovaj rad, napravljen na temelju nedavno objavljenih istraživanja, daje sintezu recentnih prostorno-vremenskih promjena u populacijama H. carunculata uz objašnjenje specifičnih uvjeta koje ova vrsta susreće u novim okolišima i potencijalnoj prijetnji koju predstavlja.The bearded fireworm, Hermodice carunculata (Pallas, 1776) is a benthic polychaete predator native to the Atlantic including the waters of the Mediterranean. This species has recently successfully established new populations along the coasts of the Mediterranean as well as in the Adriatic. Information about the species is often scarce and sporadic, but recent studies show its clear tendency of colonising new areas which, under the pressure of global changes in ecosystems, becoming warmer. For time being, this species is not yet invasive but it definitely has the potential to become one in the future. This paper, based on recent studies covering this species, provides a synthesis of recent spatio-temporal changes in H. carunculata populations along with explanations of specific conditions the species is facing in new environments and potential threat it poses

Activity comparison of the common tern (Sterna hirundo) during nesting in freshwater and marine habitats

Crvenokljune čigre (Sterna hirundo) su morske ptice koje se kolonijalno gnijezde na morskim i slatkovodnim staništima. U inkubaciji i podizanju mladunaca sudjeluju oba roditelja. U svrhu istraživanja dinamike ponašanja na gnijezdima crvenokljunih čigri različitih staništa prikupljene su serije fotografija načinjene fotozamkama smještenim na tri kolonije: dvije slatkovodne i jednoj morskoj. Fotografije sa sedam gnijezda sortirane su temeljem stanja SJEDI, PORED i NEMA temeljenih na položaju ptice na gnijezdu. Izračunato je dnevno trajanje svakog stanja, trajanje stanja do promjene i ukupni broja promjena, a analiza je napravljena i za dijelove dana. Analiza je provedena u programskom jeziku R koristeći se neparametrijskim statističkim testovima. Utvrđena je značajnu razlika u vremenu provedenom na gnijezdu među gnijezdima unutar istog, ali i među različitim tipovima staništa. Ptice na gnijezdima slatkovodnih kolonija značajno su više vremena provodile inkubirajući, dok su ptice na morskim kolonijama značajno više vremena bile odsutne, što se povezuje s lakše dostupnim izvorima hrane na slatkovodnim staništima. Predacija, intraspecijsko antagonističko ponašanje, iskustvo jedinki u gniježđenju i meteorološki uvjeti mogući su dodatni utjecaji na vrijeme provedeno u inkubaciji.The common tern (Sterna hirundo), nests colonially on both marine and freshwater habitats with incubation and chick rearing being shared parental responsibilities. In order to research the dynamics of incubation behaviour in this species, series of camera trap photographs taken between May 2021 and May 2023 were collected from three different colonies, one of which was from a marine and the two from freshwater habitats. Photographs of seven nests were sorted into three states (incubating, near nest and not present) for which the state duration per day, the state duration until change and the number of state changes were calculated. The same calculations were repeated for different times of day. Nonparametric statistical tests were conducted using the R programming language. Incubation times differed significantly among nests from the same and different habitats. Individuals on freshwater colonies spent a significantly longer time incubating, while birds from the marine habitat spent a longer time away from nest, both of which can be related to more predictable prey availability at freshwater sites. Predation, conspecific antagonistic behaviour, breeding experience and meteorological conditions are additional factors affecting incubation activity for this species

The polychaete Hermodice carunculata (Pallas, 1776) in the Adriatic Sea

Vatreni crv, Hermodice carunculata (Pallas, 1776) je bentički predatorski mnogočetinaš koji obitava diljem Atlantskog oceana, uključujući i Mediteran. To je vrsta koja je u posljednje vrijeme uspostavila niz novih populacija uz obale Sredozemnog mora pa tako i u Jadranu. Informacije o ovoj vrsti često su manjkave i sporadične, no recentna istraživanja pokazuju jasan trend koloniziranja novih prostora koji, pod pritiskom globalnih promjena ekosustava, postaju sve topliji. Zasad ova vrsta još nije prešla u kategoriju invazivne vrste no definitivno ima potencijal da to postane u budućnosti. Ovaj rad, napravljen na temelju nedavno objavljenih istraživanja, daje sintezu recentnih prostorno-vremenskih promjena u populacijama H. carunculata uz objašnjenje specifičnih uvjeta koje ova vrsta susreće u novim okolišima i potencijalnoj prijetnji koju predstavlja.The bearded fireworm, Hermodice carunculata (Pallas, 1776) is a benthic polychaete predator native to the Atlantic including the waters of the Mediterranean. This species has recently successfully established new populations along the coasts of the Mediterranean as well as in the Adriatic. Information about the species is often scarce and sporadic, but recent studies show its clear tendency of colonising new areas which, under the pressure of global changes in ecosystems, becoming warmer. For time being, this species is not yet invasive but it definitely has the potential to become one in the future. This paper, based on recent studies covering this species, provides a synthesis of recent spatio-temporal changes in H. carunculata populations along with explanations of specific conditions the species is facing in new environments and potential threat it poses

Activity comparison of the common tern (Sterna hirundo) during nesting in freshwater and marine habitats

Crvenokljune čigre (Sterna hirundo) su morske ptice koje se kolonijalno gnijezde na morskim i slatkovodnim staništima. U inkubaciji i podizanju mladunaca sudjeluju oba roditelja. U svrhu istraživanja dinamike ponašanja na gnijezdima crvenokljunih čigri različitih staništa prikupljene su serije fotografija načinjene fotozamkama smještenim na tri kolonije: dvije slatkovodne i jednoj morskoj. Fotografije sa sedam gnijezda sortirane su temeljem stanja SJEDI, PORED i NEMA temeljenih na položaju ptice na gnijezdu. Izračunato je dnevno trajanje svakog stanja, trajanje stanja do promjene i ukupni broja promjena, a analiza je napravljena i za dijelove dana. Analiza je provedena u programskom jeziku R koristeći se neparametrijskim statističkim testovima. Utvrđena je značajnu razlika u vremenu provedenom na gnijezdu među gnijezdima unutar istog, ali i među različitim tipovima staništa. Ptice na gnijezdima slatkovodnih kolonija značajno su više vremena provodile inkubirajući, dok su ptice na morskim kolonijama značajno više vremena bile odsutne, što se povezuje s lakše dostupnim izvorima hrane na slatkovodnim staništima. Predacija, intraspecijsko antagonističko ponašanje, iskustvo jedinki u gniježđenju i meteorološki uvjeti mogući su dodatni utjecaji na vrijeme provedeno u inkubaciji.The common tern (Sterna hirundo), nests colonially on both marine and freshwater habitats with incubation and chick rearing being shared parental responsibilities. In order to research the dynamics of incubation behaviour in this species, series of camera trap photographs taken between May 2021 and May 2023 were collected from three different colonies, one of which was from a marine and the two from freshwater habitats. Photographs of seven nests were sorted into three states (incubating, near nest and not present) for which the state duration per day, the state duration until change and the number of state changes were calculated. The same calculations were repeated for different times of day. Nonparametric statistical tests were conducted using the R programming language. Incubation times differed significantly among nests from the same and different habitats. Individuals on freshwater colonies spent a significantly longer time incubating, while birds from the marine habitat spent a longer time away from nest, both of which can be related to more predictable prey availability at freshwater sites. Predation, conspecific antagonistic behaviour, breeding experience and meteorological conditions are additional factors affecting incubation activity for this species