Search results for "NEST"

Conflicts between touristic recreational activities and breeding shearwaters: short-term effect of artificial light and sound on chick weight

2018

Human disturbances are increasingly becoming a conservation concern for many populations of colonial seabirds. Colonially reproducing species are particularly vulnerable to localised disturbances because detrimental elements can simultaneously affect the entire population. Studies of petrels and shearwaters have shown that light pollution, in particular, can be harmful for both fledglings and adults, but little is known of the way such anthropogenic elements affect the quality of parental care at the nest. Chick provisioning in petrels and shearwaters occurs exclusively at night and is also negatively correlated with the amount of moonlight. We tested the hypothesis that high-intensity ligh…

Deceiving predators: linking distraction behavior with nest survival in a ground-nesting bird

2016

The Function of Stones in Nest Building: The Case of Black Wheatear (Oenanthe Leucura) revisited

2016

Black Wheatears ( Oenanthe leucura) transport to breeding territories, including the nest, a large number of stones. Currently, there is negative evidence that stones serve for nest support, thermoregulation, weather protection or anti-predation, but in males, this behaviour appears to represent a form of post-mating display. This ‘sexual selection’ hypothesis, however, does not explain why females also carry stones, and why many stones are associated with the nest. We examined stone distribution and morphology in 277 abandoned nests of Black Wheatears from an arid area of southeastern Spain. Nests were built on the ground (14.4%), or in cracks (7.2%), cavities (54.6%) and ledges (23.8%) a…

Crocodile egg sounds signal hatching time.

2008

Summary Crocodilians are known to vocalize within the egg shortly before hatching [1,2]. Although a possible function of these calls — inducing hatching in siblings and stimulating the adult female to open the nest — has already been suggested, it has never been experimentally tested [1–5]. Here, we present the first experimental evidence that pre-hatching calls of Nile crocodile ( Crocodylus niloticus ) juveniles are informative acoustic signals which indeed target both siblings and mother.

Negative Effects of High Temperatures During Development on Immediate Post-Fledging Survival in Great TitsParus major

2016

We analyzed the effect of nest temperatures, fledging date, age at fledging, fledgling mass and size on postfledging survival of Great Tits Parus major in eastern Spain. We manipulated temperature during nestling development in 26 nests (average temperature was 39.8, 34.6 and 26.4 °C for heated, control and cooled nest-boxes, respectively), and used radio-telemetry to monitor the survival of 48 nestlings (16 heated, 18 cooled, 14 controls) during the first 15 days after fledging. Heated chicks were lighter than control and cooled chicks. Estimated survival of heated fledglings was lower than that of controls. Additionally, survival of control fledglings increased with size, but this relatio…

Breeding success of the Great Tit Parus major in relation to attributes of natural nest cavities in a primeval forest

2015

An overlap in attributes of nest cavities used by Great Tit Parus major across Eurasia suggests similar nest site preferences within the geographical range, although the drivers of these preferences are unclear. To determine whether preferred cavities provide conditions enhancing successful reproduction, we investigated the breeding performance of Great Tits in relation to tree cavity characteristics using data collected during 2008–2011 in primeval conditions (Białowieża National Park, Poland). Here, tree cavities are diverse and superabundant but nesting birds are at risk from a variety of predators. According to expectations, nest losses were high (60 % of Great Tit nests failed), mostly…

Nest Insulating Capacity during Incubation and after Fledging are Related

2016

Most birds build nests to hold eggs and nestlings. An important property of nests is their ability to keep eggs and nestlings at an optimum temperature. This is usually measured as the insulating capacity (IC); nests with a higher IC will keep their content warm for longer. The usual protocol to estimate IC involves collecting nests after fledging of the young. However, nest properties change throughout the nesting period, potentially affecting IC. Therefore, a relevant question is whether the nest IC, measured after fledging, actually reflects its IC during incubation and early nestling development, when it is most crucial. In April 2015, we collected 18 Great Tit ( Parus major) nests 3-4…

The role of partial incubation and egg repositioning within the clutch in hatching asynchrony and subsequent effects on breeding success

2019

The main mechanism to achieve hatching asynchrony (HA) for incubating birds is to start heating the eggs before clutch completion. This might be achieved through partial incubation and/or early incubation. Even in the absence of incubation behaviour during the laying phase, clutches still experience a certain degree of asynchrony. Recent studies have shown that eggs located in the centre of the nest receive more heat than peripheral ones during incubation. As eggs receiving more heat would develop faster, we hypothesized that HA should be shorter in nests where eggs were moved homogeneously along the centre–periphery space during incubation than in those nests where eggs repeatedly remained…

Cohabitation of tree holes by ants and breeding birds in a temperate deciduous forest

2015

A previously unknown association of ants with birds breeding in tree holes is described. Ants Lasius brunneus Latreille (Hymenoptera: Formicidae) were found in c. 15% of nests of Parus major L. and Poecile palustris L. (Paridae) breeding in tree holes in the primeval deciduous forest located in the Białowieża National Park (Poland). The ants preferably used holes located higher above the ground. As such holes are warmer than the unused holes or other nest sites, it is suggested that the ants cohabit holes utilized by the tits to gain thermal benefits.

First data on microflora of loggerhead sea turtle (Caretta caretta) nests from the coastlines of Sicily (Italy)

2020

ABSTRACT Caretta caretta is threatened by many dangers in the Mediterranean basin, but most are human-related. The purposes of this research were: (i) to investigate microflora in samples from six loggerhead sea turtle nests located on the Sicilian coast and (ii) to understand microbial diversity associated with nests, with particular attention to bacteria and fungi involved in failed hatchings. During the 2016 and 2018 summers, 456 eggs and seven dead hatchling from six nests were collected. We performed bacteriological and mycological analyses on 88 egg samples and seven dead hatchlings, allowing us to isolate: Fusarium spp. (80.6%), Aeromonas hydrophila (55.6%), Aspergillus spp. (27.2%) …