Nest Predation May Not Explain Poor Reproductive Success of Polygynously Mated Female Tengmalm's Owls

1994 ◽  
Vol 25 (2) ◽  
pp. 161 ◽  
Author(s):  
Erkki Korpimaki
Keyword(s):  
Reproductive Success ◽  
Nest Predation ◽  
Mated Female

scholarly journals The influence of subcolony-scale nesting habitat on the reproductive success of Adélie penguins

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Annie E. Schmidt ◽  
Grant Ballard ◽  
Amélie Lescroël ◽  
Katie M. Dugger ◽  
Dennis Jongsomjit ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Colony Size ◽  
Nest Predation ◽  
Size Variation ◽  
Area Ratio ◽  
Slope Aspect ◽  
Nesting Habitat ◽  
Terrain Attributes ◽  
Small Colony ◽  
Adélie Penguins

AbstractGroup-size variation is common in colonially breeding species, including seabirds, whose breeding colonies can vary in size by several orders of magnitude. Seabirds are some of the most threatened marine taxa and understanding the drivers of colony size variation is more important than ever. Reproductive success is an important demographic parameter that can impact colony size, and it varies in association with a number of factors, including nesting habitat quality. Within colonies, seabirds often aggregate into distinct groups or subcolonies that may vary in quality. We used data from two colonies of Adélie penguins 73 km apart on Ross Island, Antarctica, one large and one small to investigate (1) How subcolony habitat characteristics influence reproductive success and (2) How these relationships differ at a small (Cape Royds) and large (Cape Crozier) colony with different terrain characteristics. Subcolonies were characterized using terrain attributes (elevation, slope aspect, slope steepness, wind shelter, flow accumulation), as well group characteristics (area/size, perimeter-to-area ratio, and proximity to nest predators). Reproductive success was higher and less variable at the larger colony while subcolony characteristics explained more of the variance in reproductive success at the small colony. The most important variable influencing subcolony quality at both colonies was perimeter-to-area ratio, likely reflecting the importance of nest predation by south polar skuas along subcolony edges. The small colony contained a higher proportion of edge nests thus higher potential impact from skua nest predation. Stochastic environmental events may facilitate smaller colonies becoming “trapped” by nest predation: a rapid decline in the number of breeding individuals may increase the proportion of edge nests, leading to higher relative nest predation and hindering population recovery. Several terrain covariates were retained in the final models but which variables, the shapes of the relationships, and importance varied between colonies.

scholarly journals Nesting With The Wasp Ropalidia Cincta Increases Nest Success of Red-Cheeked Cordonbleu (Uraeginthus Bengalus) in Ghana

The Auk ◽  
2006 ◽  
Vol 123 (4) ◽  
pp. 1022-1037 ◽  
Author(s):  
Paul Beier ◽  
Agba Issahaku Tungbani
Keyword(s):  
Reproductive Success ◽  
Nest Predation ◽  
Northern Ghana ◽  
Social Hymenoptera ◽  
Tropical Regions ◽  
Nest Sites ◽  
Wasp Nests ◽  
Habitat Feature ◽  
Working Hypotheses ◽  
Rule Out

AbstractAssociations between birds and social Hymenoptera (ants, wasps, bees) are common in tropical regions and are usually assumed to be commensal relationships that benefit birds but neither help nor harm the arthropods. However, benefits to birds have been documented in only four such associations, and no previous research has rigorously investigated costs or benefits to associated hymenopterans. We followed the nesting cycles of an estrildid finch, the Red-cheeked Cordonbleu (Uraeginthus bengalus), and a common nesting associate, the wasp Ropalidia cincta, during 2002 and 2003 in northern Ghana to compare reproductive success of birds and wasps nesting in association with that of birds and wasps nesting separately. Red-cheeked Cordonbleus and wasps nested together in the same tree 3.7 × as often as expected if nesting decisions were made independently, with 74% of bird nests and 74% of wasp colonies occurring in associations. Bird nesting was initiated ≈33 days after founding of an associated wasp colony; bird nests and wasp colonies were, on average, 42 cm apart. In both years, Red-cheeked Cordonbleus in nesting associations with wasps were twice as likely to fledge young as birds nesting in trees without wasps. Reduced predation was apparently a major reason for increased fledging success: we documented four cases of nest predation on 122 Red-cheeked Cordonbleu nests associated with wasps, and 11 cases on 90 nests not associated with wasps. Association with birds did not affect the success of wasp colonies. Although our observational study cannot rule out the possibility that both species coincidentally shared a preference for a habitat feature in limited supply, suitable nest sites did not appear to be limiting (74% of potential nest trees had neither bird nor wasp nests). Reproductive success of Red-cheeked Cordonbleu populations in this region may be limited by the number of available wasp colonies. By designing our study to address four working hypotheses (commensalism, mutualism, parasitism, coincidence of habitat preference), we have provided strong evidence that this relationship is commensal.Augmentation du Succès de Nidification de Uraeginthus bengalus Nichant avec des Guêpes Ropalidia cincta au Ghana

The influence of microtines on polygyny, productivity, age, and provisioning of breeding Northern Harriers: a 5-year study

1986 ◽  
Vol 64 (11) ◽  
pp. 2447-2456 ◽  
Author(s):  
Robert Simmons ◽  
Phoebe Barnard ◽  
Bruce MacWhirter ◽  
Gay L. Hansen
Keyword(s):  
Reproductive Success ◽  
New Brunswick ◽  
Clutch Size ◽  
Nest Predation ◽  
Strong Relationship ◽  
Prey Abundance ◽  
Nest Defence ◽  
Young Females ◽  
Circus Cyaneus ◽  
The Difference

Breeding Northern Harriers, Circus cyaneus, and their principle prey, the vole Microtus pennsylvanicus, underwent synchronous fluctuations in New Brunswick between 1980 and 1984. Microtines were abundant in 1980 and 1983 and were significantly tracked by the number of nesting harriers (r = 0.90), the number of polygynous males (r = 0.89), the number of harem females (r = 0.90), and the mean clutch size (r = 0.94), but not the reproductive success of successful females (r = 0.72). Male nest defence likewise exhibited a strong relationship (r = 0.99, n = 3) with prey abundance, but nest predation did not. An unexpected association with prey abundance was the greater proportion of young females (≤ 2 years) breeding at vole lows; the reverse was true for yearling males. Young females that did breed at vole highs were significantly more productive than were old females breeding at highs. The difference arose principally through nest predation. Successful females also consistently reared significantly greater proportions of their hatchlings when voles were increasing than when they were decreasing. Our results suggest that New Brunswick harriers were affected by prey fluctuations in most aspects of their reproduction and population dynamics. Significant correlations between male food provisioning rates and clutch size and reproductive success over 3 years provide a proximate mechanism through which fecundity may vary annually. They may also provide a proximate pathway mediating for polygyny.

Reproductive Success and Nest Predation in the Superb Lyrebird, Menura superba

1980 ◽  
Vol 7 (2) ◽  
pp. 271 ◽  
Author(s):  
a Lill
Keyword(s):  
Reproductive Success ◽  
Breeding Success ◽  
Nest Predation ◽  
Ground Level ◽  
Recruitment Rate ◽  
Circumstantial Evidence ◽  
Above Ground Level ◽  
Breeding Female ◽  
Nest Sites ◽  
Native Birds

Breeding success and nest predation were analysed in two superb lyrebird populations studied over six years. Egg success was estimated at 11-20%, giving an annual recruitment rate of 0.1-0.2 fledglings per breeding female. Predation accounted for at least 79% of nesting mortality and the risk was greater during the nestling phase. Preferred nest sites were 0.6-1.8 m above ground level on earth banks and in trees but were most susceptible to predation. Circumstantial evidence implicated native birds and introduced mammals as the principal nest predators. The generality and evolutionary implications of these findings are discussed.

scholarly journals Reproductive Success of Wood Thrushes in Forest Fragments in Northern Indiana

The Auk ◽  
2000 ◽  
Vol 117 (1) ◽  
pp. 194-204 ◽  
Author(s):  
Peter T. Fauth
Keyword(s):  
Reproductive Success ◽  
Nest Predation ◽  
Forest Edge ◽  
Negative Influence ◽  
Forest Area ◽  
Forest Fragments ◽  
Regional Demography ◽  
Source Sink ◽  
Wood Thrushes ◽  
Seasonal Fecundity

AbstractI monitored 278 Wood Thrush (Hylocichla mustelina) nests in 14 forest fragments (range 7 to 500 ha) in northern Indiana to explore patterns of brood parasitism by Brown-headed Cowbirds (Molothrus ater), nest predation, and reproductive success. Density of thrushes was negatively related to area of forest fragments. Cowbirds were common throughout the landscape, but I found no relationship between their abundance and forest area. Overall, 90% of the thrush nests were parasitized by cowbirds (x̄ = 2.4 cowbird eggs per nest). The number of cowbird eggs per thrush nest was not related to forest area, abundance of host species, or distance to a forest edge but was positively related to thrush abundance. Nest predation rates averaged 58% and were lower than those reported in much of neighboring Illinois but also were unrelated to forest area and distance to a forest edge. The combination of cowbird parasitism and nest predation resulted in relatively low reproductive success (x̄ = 0.6 thrush fledglings per nesting attempt). I estimated that Wood Thrushes in northern Indiana made an average of three nesting attempts per breeding season (based on 17 color-marked females) and had relatively low seasonal fecundity (x̄ = 0.9 female fledglings per adult female per season). Nonetheless, considerable annual variation in seasonal fecundity suggested that some sites exceeded the source-sink threshold in some years. Regardless, the overall landscape appeared to be part of a regional sink for Wood Thrushes, although its negative influence on regional demography was not as severe as elsewhere in the midwestern United States. The poor demographic balance in much of the agriculturally dominated Midwest suggests that conservation efforts for Wood Thrushes and other Nearctic-Neotropical migrants should be directed at preserving and enhancing possible source habitats in regions where parasitism by cowbirds and nest predation are reduced.

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