Nest-site Reuse Research Articles

Nest-Site Reuse by the White-Collared Swift Streptoprocne zonaris in Rocky Caves in South-Central Cuba

Nest-Site Reuse by the White-Collared Swift Streptoprocne zonaris in Rocky Caves in South-Central Cuba

Natural nest sites of the European Starling Sturnus vulgaris in a primeval temperate forest

ABSTRACT Capsule European Starlings Sturnus vulgaris nested mostly in natural holes with strong walls (in live trees), typically excavated by medium-sized woodpeckers (small entrances, deep cavities), and high above the ground. Co-occurrence of these safety-enhancing features suggests that predation avoidance has been the main force shaping patterns of Starling nest site selection. Aims To describe patterns of nest site use by Starlings in a primeval forest and to assess the adaptive value of nest site choice. Methods Observations were made of Starlings breeding in undisturbed conditions in a strictly protected part of the Białowieża National Park, Poland. Intensive searches were made for nests (n = 2039) in permanent observation plots during 46 breeding seasons (1975–2020), coupled with measurements of hole attributes and observations of fate and re-use of nest sites. Results Starlings bred along forest edges in holes located in several species of deciduous tree; tree species used differed among habitats and hole location differed across tree species. The birds bred mostly in holes excavated by woodpeckers (70.3%), in trunks (77.4%) of living trees (84.5%). The median girth at breast height of these trees amounted to approximately 170 cm and median height of holes above the ground was 13 m. Starlings used holes excavated by the medium-sized woodpeckers roughly in proportion to their availability in the forest (tree species, stature, height above the ground). About 39% of holes were re-used in the consecutive years, with some holes being used over several decades. Conclusion The features of Starling nest holes (strong walls, narrow entrances, deep cavities) probably constitute adaptations to the need to evade predators. Their body size allows them to nest in excavated holes without threat of their broods being destroyed by woodpeckers.

Conspecific brood parasitism in an upland-nesting bird: cues parasites use to select a nest

Among birds exhibiting conspecific brood parasitism (CBP), parasites demonstrate a variety of intriguing tactics for selecting a host nest, including preference for safe nests (i.e., avoiding nests depredated during the previous season). Brood parasites of birds that do not reuse nest sites, however, are limited to nest-site information available to them during the current breeding season. This study explores cues used by brood parasites in a population of red-breasted mergansers nesting in upland vegetation and sandy substrate that prohibits reuse of nest sites in consecutive years. Nest-site and host traits were measured for 33 parasitized and 23 non-parasitized nests. There was no association between CBP and nest-site traits potentially providing cues about nest safety from avian predators (concealment and density of nesting larids), likely due to very low rates of egg predation. Distance to shore for parasitized nests was slightly greater than for unparasitized nests. Parasites did not select nests in relation to host age, mass, date of nest initiation, or stage of nesting (laying or incubation). Artificial nests were used to simulate natural nests without a host and to assess whether host presence serves as a cue for parasites. The proportion of natural nests receiving ≥ 1 foreign egg (60% of 15 nests) was thrice that for artificial nests (21% of 14 nests). Some aspect of host presence may therefore be an important, but not necessary, cue for brood parasites targeting nests that are heavily concealed in uplands. Whenever brood parasitism is a well-developed component of reproduction, selection is expected to favor brood parasites that make use of environmental or social information allowing them to discriminate among host nests and maximize reproductive success. We assessed cues used by brood parasites in ground-nesting red-breasted mergansers for which conspecific brood parasitism (CBP) is common, and nests are well concealed in upland vegetation. Observations at parasitized and unparasitized nests revealed that nest-site safety and visibility from habitat edges are not central to laying decisions by parasites in this population. Brood parasites, however, were considerably more likely to lay their eggs in natural nests with a host than in artificial nests without a host, suggesting that some aspect of host presence is important in the nest-site selection process for parasites. The ability of brood parasites to discriminate among nests based on host presence is expected to affect parasite success because individuals can avoid nests in which their eggs are doomed to fail (e.g., abandoned nests).

Breeding biology of the Sayaca Tanager (Thraupis sayaca) in southeast Brazil

ABSTRACTThraupis is a genus of the American endemic Thraupidae (subfamily Thraupinae), comprising seven species that inhabit tropical forests to urban centres. The Sayaca Tanager (Thraupis sayaca) is a disturbance-tolerant species of high representativeness in plant-frugivore networks, but information on its breeding biology is scarce and often restricted to non-systematic surveys. We studied the breeding biology of the T. sayaca, following 39 active nests in a periurban area of southeast Brazil during two breeding seasons (2017/2018, 2018/2019). The breeding season ranged from early September to middle December, and the nests were placed in native and exotic plants and human buildings (nest height above ground: 3.35 ± 1.73 m, mean ± SD). Only females incubated and brooded, but both adults built the nests, fed the nestlings, and removed their faecal sacs. Clutch size was 2.86 ± 0.38 eggs and nest attentiveness was 71.2%. The incubation and nestling periods were, respectively, 13.4 and 17.4 days. Males and females did not differ on nestling provisioning and nest sanitation rates. Nestling provisioning (13.35 ± 6.25 trips/hour) increased with nestling age, while mean brooding time was 37.2% and decreased with nestling age. Apparent nest success was 38.7%, and nest survival according to the Mayfield method was 27.2%. Five nests (20.8%) were parasitised by the Shiny cowbird (Molothrus bonariensis), and we recorded five events of nest-site reuse. We concluded that the most remarkable breeding traits of T. sayaca in comparison with close-related tanagers are the use of anthropogenic nest sites, the higher clutch size and number of feeding trips, and the longer nestling period.

Nest-Site Selection In A High-Density Colony of Burrowing Owls

Although many Western Burrowing Owl (Athene cunicularia hypugaea) populations have been declining, a high-density population nests at the National Radio Transmission Facility (NRTF), Dixon, California. We compared density at NRTF to densities elsewhere, and nest-site use and reuse to available nest substrates. Breeding pairs numbered 24–44 per year, averaging 34 pairs on 83 ha, the fourth-highest on record. Occupancy of eight artificial nest sites installed in 2000 declined from six pairs in 2006 to one pair in 2007 and 2008, and none afterward. Nearest-neighbor distance among artificial nests averaged half the distance among nest sites in fossorial mammal burrows and concrete half-rounds covering aboveground power cables. Undisturbed clay soils supported pocket gophers (Thomomys bottae) but few ground squirrels (Spermophilus beecheyi), whereas disturbed soils supported both ground squirrels and Burrowing Owls. The presence of both ground squirrels and Burrowing Owls was associated with backfill soils over buried cable, cable covers, and areas where soils bordered impervious surfaces. Nest-site reuse was low, with only 12% of the sites occupied in all study years, 2006–2011. Most (78%) nest sites reused in a subsequent year involved nests in a different burrow or cable cover opening >1 m from the previous year's nest. We recommend research on whether concrete half-rounds might outperform buried utility boxes as artificial nests, especially in conjunction with efforts to conserve the fossorial mammals that naturally excavate burrows used by Burrowing Owls.

Re-Use of Nest Sites by Marbled Murrelets (Brachyramphus marmoratus) in British Columbia

Marbled Murrelets (Brachyramphus marmoratus) nest predominantly in the canopies of large old-growth conifers, and are listed as Threatened in Canada and 3 US states mainly as a consequence of reductions in this habitat due to logging. We assessed the re-use of nest sites (nest trees) by murrelets in British Columbia using 3 types of data: 1) evidence o fr eturn of adults to the same nest site; 2) evidence of multiple nests within the same tree; and 3) re-checking known nest trees in subsequent seasons for evidence of re-use. All 3 methods showed evidenc eo f re-use of nest trees in different years, but there were marked regional differences in the degree of re-use. Re-use of nest trees was most frequent in regions with extensive loss of nesting habitat due to logging (Southern Mainland Coast and East Vancouver Island), and rare in a less disturbed region (West Vancouver Island). Overall, 26 of 143 (18%) nest trees climbed showed evidence of multiple nesting in separate seasons. Management of nesting habitat should incorporate these results by providing greater protection of habitat in regions where habitat is sparse, and by minimizing predation risk where murrelets more frequently re-use nest sites. Since re-use of nest sites is infrequent, managers should aim to provide murrelets with multiple choices for nest sites, such as maintaining large tracts of old- growth forest with many large trees containing potential nest platforms.

Nesting Behavior of Gorilla gorilla diehli at Kagwene Mountain, Cameroon: Implications for Assessing Group Size and Density

We recorded nesting data at 569 fresh night nest sites, comprising 7032 individual nests, of Cross River gorillas inhabiting the Kagwene Mountain in western Cameroon. The mean night nest group size was 12.4. Overall, 55% of night nests were constructed on the ground and 45% in trees. Significantly more arboreal nests were constructed in the wet season (69%), vs. the dry season (19%). Day nest construction was common at Kagwene (n = 260 nest sites, mean nest group size = 5.98) and we encountered significantly more day nest sites in the wet season. Nest site reuse was also common (35%), though not related to season. Our results of nesting habits concur with those from other western gorilla studies, in which rainfall influences arboreal nesting. However, we encountered wet season arboreal nesting, day nest construction, and overall nest site reuse more frequently than reported for other sites. Our observations have considerable implications when estimating group size and density using traditional nest count data. The gorillas at Kagwene inhabit the highest altitudinal range of all Cross River gorilla subpopulations and rainfall is also high; therefore other subpopulations may demonstrate different nesting characteristics. However, one should consider our findings when attempting to estimate Cross River gorilla density at other localities through nest site data.

Nest-site Fidelity in American Alligators in a Louisiana Coastal Marsh

Little is known about nest-site fidelity in wild Alligator mississippiensis (American Alligator). As part of a long-term study on multiple paternity and mate fidelity that required capture and marking of nesting female alligators, we documented several instances of nest-site reuse by individual females. In one case, the female nested at the same site seven years after initial capture, demonstrating long-term nest-site fidelity. Another female used one nest site in 2000, 2002, and 2004. Herein, we provide data on minimum nesting intervals for recaptured alligators, including three cases of females nesting in two consecutive years. Despite tremendous habitat alteration and storm surge from Hurricane Rita in 2005 and a catastrophic drought precluding nesting in 2006, we found female alligators in 2007 at nests within 20 m and 170 m of their nest sites from seven years and three years, respectively, prior to those events.

Nest and nest-site reuse within and between breeding seasons by three neotropical flycatchers (Tyrannidae)

Nest and or nest site reuse within and between breeding seasons was reported by the Euler's Flycatcher (Lathrotriccus euleri), the Sepia-capped Flycatcher (Leptopogon amaurocephalus) and the Gray-hooded Flycatcher (Mionectes -rufiventris) in forest fragments from southeastern Brazil. Nest and or nest site reuse between some years was frequent within a single breeding season by the Sepia-capped Flycatcher. Nest reuse, however, was not related to nesting success in the previous breeding attempt. Nest turnover rates (movement to a new site between years) were low for L. amaurocephalus, intermediate for L. euleri and high for M. rufiventris.

Philopatry, Dispersal Patterns and Nest-site Reuse in Lesser Grey Shrikes (Lanius minor)

To nest in the same breeding area, territory or even nest-site in successive years may provide a possibility to look at mechanisms involved in breeding habitat selection and could also be an important tool for conservation, management and restoration attempts. In this study we examine site fidelity towards the breeding area as well as the nesting site in a dense and stable population of the Lesser Grey Shrike Lanius minor, a long-distance migrant and highly endangered passerine species, at its present northern border of its breeding range. Overall we recovered 48 out of 146 (32.8%) adults between 1996 and 2000. Recovery rate is significantly higher for males (31 of 77, 40.25%) than for females (17 of 69, 24.6%). Recovery rate of nestlings is much lower since only 51 of 790 (6.5%) were recovered and there is no significant sex difference. Furthermore, our results from 1989 to 2000 revealed that more than 30% (97/319) of the nests were built in the same nest tree in successive years and more than half (183/319 = 57.4%) of the nests in the same or neighboring trees (up to 20 m), but very seldom by the same individuals. The fact that nest reuse in successive years is almost exclusively done by different individuals suggests habitat copying and public information of individual birds. Due to optimal ecological breeding conditions other parameters like inbreeding avoidance or increased genetic variability could be important factors in nest-site selection strategies and consequently result in a “disperse over stay strategy”.

Low Frequency of Site Fidelity by Golden-Fronted Woodpeckers

Interest in site fidelity is rooted in its influence on population structure, including dispersal and recruitment (Shields, 1984). Familiarity with the local habitat is increased through fidelity, which in turn may enhance defendability and access to the best nesting, staging, and wintering sites. Factors proposed that might influence the degree of site tenacity include age, sex, local habitat and nest-site stability, and prior breeding experience (Shields, 1984). Ideally, statistical analysis of site fidelity should include data on mortality-survival rates and dispersal distance. For the golden-fronted woodpecker (Melanerpes aurifrons) these data are unavailable (Husak and Maxwell, 1998) so we discuss site faithfulness in this species relative to that documented for congeners. Fidelity has been documented among migratory and non-migratory birds (e.g., Freer, 1979; Greenwood, 1980; Shields, 1984; Blancher and Robertson, 1985; Rimmer and Darmstadt, 1996; Flint et al., 2000; Weggler, 2000), but few studies have focused on woodpeckers. In North America, nest-site fidelity has been documented in red-cockaded (Picoides borealis; Jackson, 1994), red-headed (Melanerpes erythrocephalus), and red-bellied (M. carolinus) woodpeckers (Ingold, 1991), and migratory northern flickers (Colaptes auratus), and yellow-bellied sapsuckers (Sphyrapicus varius; Lawrence, 1967). The only site fidelity data for golden-fronted woodpeckers prior to our research involved anecdotal observations of re-use of nest sites over

NESTING BIOLOGY OF TAPACULOS (RHINOCRYPTIDAE) IN FRAGMENTED SOUTH-TEMPERATE RAINFORESTS OF CHILE

Abstract We studied the effect of forest fragmentation on the nesting biology and reproductive success of three species of tapaculos (Rhinocryptidae) in relation to forest size, edge effects, and disturbance from livestock or logging over a 6-year period (1993–1999) in Chilean temperate rainforest. Overall, Mayfield nest success (n = 360) among the three species ranged from 64% to 85%, and predation accounted for 64% of nest losses. Considering all types of losses, nest mortality was similar in fragmented and unfragmented forest, but predation was higher in fragmented forest. Successful nest sites of the Chucao Tapaculo (Sclerochilus rubecula; the species with the largest sample size) were nearer forest edges, better concealed, closer to the ground, and had longer entrance tunnels, on average, than depredated nests. Reuse of nest sites by chucaos was more common in forest fragments with livestock or logging than in undisturbed forests, but reuse was independent of forest size. Success of second broods was...

Use of retained trees for nesting by birds in logged eucalypt forest in north-eastern Tasmania

In a previous study in eucalypt forest in north-eastern Tasmania four hollow-nesting bird species (striated pardalote Pardcilotus striatus, green rosella Platycercus caledonicus, laughing kookaburra Dacelo novaeguineae and yellow-tailed black cockatoo Calyptorynchus funereus) were recorded in 1989 using hollows in 29 trees, with re-use being documented in 1990 when an additional nest tree was discovered. The present study was undertaken in 1995/96 after logging of part of the area, and a wildfire. Several nest trees were destroyed during the logging. In the logged areas, or patches or strips surrounded by logged forest, 19% of trees were windthrown or had lost the limb containing the nest. Re-use of the tree hollows by birds was examined for the 22 remaining trees. Only striated pardalotes were recorded as re-using previous nest sites following logging; 24% of these nest sites were being re-used in 1995/96 compared with 74% in 1990. Reuse of nest sites in 1995/96 appeared to be influenced by location; three of the four nest trees located in retained strips, one of the seven in logged areas and none of the six nest sites in unlogged forest were re-used. Tree martins (a species not recorded nesting in the area before logging) and striated pardalotes were observed in the logged area nesting in trees which had not been recorded as nest sites before logging, and green rosellas were observed using a hollow in a tree within a streamside reserve within the logged area.