Investigator disturbance reduces reproductive success in Short‐tailed Shearwaters Puffinus tenuirostris

Abstract

Research procedures can have a detrimental effect on the reproductive success of the study species. In this study, the frequency of investigator disturbance on Short‐tailed Shearwaters Puffinus tenuirostris was examined experimentally throughout the incubation period to assess whether disturbance influences hatching success, pre‐fledging chick survival and chick body size. Handling of incubating birds every day, every 3 days and once a week reduced hatching success by 100, 61 and 39%, respectively, compared with pairs that were not disturbed. Most failures resulted from egg abandonment by the parents, particularly during the early stage of incubation. Chick survival did not differ between treatment groups, but control chicks were significantly heavier and had larger bill depths and longer wings. The difference in chick body mass and size observed between the control and disturbed chicks might be due to physiological or behavioural mechanisms in adults or carry‐over effects from the incubation stage to the next life‐history stage. Reduced offspring quality has the potential to affect post‐fledging survival and recruitment. These findings are significant in broader terms because any investigator disturbance that reduces reproductive success, survival and offspring fitness could interfere with the accurate assessment of demographic parameters and exacerbate population declines.

The impact of researcher disturbance on nest predation rates: a meta‐analysis

“…However, it is possible that this reduction in nest predation will negatively affect nest predators. Moreover, research activities could negatively affect the focal species in other subtle ways, such as a change in breeding density or an increase in the level of stress that may result in lower fitness (Carey 2011). Therefore, managers should evaluate carefully their main conservation goals when granting research projects for the areas under their supervision.…”

Discriminating uniparental and biparental breeding strategies by monitoring nest temperature

“…assigning an incubation strategy, documenting recess activity or monitoring the nest survival) can be achieved by visiting the nest-site only once during incubation, the disturbance by observers and possible related biases can be reduced to a minimum. Indeed, frequent visits to nests may reduce nest attendance by parents and increase the risk of nest abandonment or nest predation (Ellison & Cleary 1978, Lenington 1979, Westmoreland & Best 1985, Major 1990, Gotmark 1992, Verboven et al 2001, Weidinger 2006, Carey 2011, but see also Ibañez-Alamo et al 2012). This concern is important in the Arctic where many nests are depredated by Arctic Foxes Vulpes lagopus (Reneerkens et al 2016), which have an excellent sense of smell (Kolenosky 1987, Lai et al 2015.…”

“…Furthermore, frequent visits to the nest necessarily induce some anthropogenic impacts and can hence bias other parameters under study. Indeed, previous studies showed that the presence of an observer might alter the behaviour of birds (Weidinger 2006, Carey 2011, can reduce nest attendance by parents (Verboven et al 2001), and increase the likelihood of nest abandonment (G€ otmark 1992) or nest predation (Major 1990). This is particularly the case for studies of species with little or no sexual dimorphism, requiring researchers to catch and mark individually at least one of the incubating adults to identify whether one or two adults are incubating a clutch.…”

To change or not to change experimenters: caveats for repeated behavioural and physiological measures in Montagu's harrier

“…Indeed, most of the time, the impact of investigators is seen from the disturbance effect point of view either on breeding success (Bolduc and Guillemette 2003, Blackmer et al 2004, Ibáñez-Álamo et al 2012, growth of chicks (Sandvik and Barrett 2001, O'Dwyer et al 2006, Carey 2009, 2011, or on behaviour and physiology (van Oers and Carere 2007) but rarely, to our knowledge, considering the identity of the people in charge of the experiment on wildlife fauna (see, however, Slobodchikoff et al 1991, Levey et al 2009, Marzluff et al 2010, Lee et al 2011, Davidson et al 2015. Indeed, most of the time, the impact of investigators is seen from the disturbance effect point of view either on breeding success (Bolduc and Guillemette 2003, Blackmer et al 2004, Ibáñez-Álamo et al 2012, growth of chicks (Sandvik and Barrett 2001, O'Dwyer et al 2006, Carey 2009, 2011, or on behaviour and physiology (van Oers and Carere 2007) but rarely, to our knowledge, considering the identity of the people in charge of the experiment on wildlife fauna (see, however, Slobodchikoff et al 1991, Levey et al 2009, Marzluff et al 2010, Lee et al 2011, Davidson et al 2015.…”