Geology topics

Rose J. Swift

Publications and source records attributed to Rose J. Swift.

22 records · Page 2Linked to original sources

USGS2021

Impacts of extreme environmental disturbances on piping plover survival are partially moderated by migratory connectivity

Effective conservation for listed migratory species requires an understanding of how drivers of population decline vary spatially and temporally, as well as knowledge of range-wide connectivity between breeding and nonbreeding areas. Environmental conditions distant from breeding areas can have lasting effects on the demography of migratory species, yet these consequences are often the least understood. Our objectives were to 1) evaluate associations between survival and extreme environmental disturbances at nonbreeding areas, including hurricanes, harmful algal blooms, and oil spills, and 2) estimate migratory connectivity between breeding and nonbreeding areas of midcontinental piping plovers ( Charadrius melodus ). We used capture and resighting data from 5067 individuals collected between 2002 and 2019 from breeding areas across the midcontinent, and nonbreeding areas throughout the Gulf of Mexico and southern Atlantic coasts of North America. We developed a hidden Markov multistate model to estimate seasonal survival and account for unobservable geographic locations. Hurricanes and harmful algal blooms were negatively associated with nonbreeding season survival, but we did not detect a similarly negative relationship with oil spills. Our results indicated that individuals from separate breeding areas mixed across nonbreeding areas with low migratory connectivity. Mixing among individuals in the nonbreeding season may provide a buffering effect against impacts of extreme events on any one breeding region. Our results suggest that understanding migratory connectivity and linking seasonal threats to population dynamics can better inform conservation strategies for migratory shorebirds.

Biological Conservation↗

USGS2020

Asymmetric benefits of a heterospecific breeding association vary with habitat, conspecific abundance and breeding stage

Heterospecific breeding associations may benefit individuals by mitigating predation risk but may also create costs if they increase competition for resources or are more easily detectable by predators. Our understanding of the interactions among hetero‐ and conspecifics is often lacking in mixed species colonies. Here, we test how the presence of hetero‐ and conspecifics influence nest and chick survival for two listed (under the U.S. Endangered Species Act) migratory species breeding on the Missouri River, USA. We monitored 2507 piping plover Charadrius melodus nests and 3245 chicks as well as 1060 least tern Sternula antillarum nests and 1374 chicks on Lake Sakakawea, the Garrison River Reach and the Gavins Point Reach for varying years between 2007 and 2016. Piping plover nest and chick survival improved with the presence and abundance of least terns, but least terns only benefited from piping plover presence for certain study areas and breeding stages. Piping plover nest survival was also improved by the presence and abundance of conspecifics on the Garrison River Reach and was negatively influenced by conspecific presence on Lake Sakakawea. Least tern chick survival improved with the presence of other least terns only on the Gavins Point Reach. Ultimately, the heterospecific breeding association between plovers and terns is mutualistic but asymmetric and is moderated by habitat, abundance of conspecifics and breeding stage. Our results highlight that spatiotemporal variation in the interactions among individuals breeding in groups precludes simple generalizations and suggests that management focused on one species may restrict benefits to that focal species if nest site requirements for heterospecifics are not also included.

Nebraska, North Dakota, South Dakota↗

USGS2020

Low renesting propensity and reproductive success make renesting unproductive for the threatened Piping Plover (Charadrius melodus)

Upon reproductive failure, many bird species make a secondary attempt at nesting (hereafter, “renesting”). Renesting may be an effective strategy to maximize current and lifetime reproductive success, but individuals face uncertainty in the probability of success because reproductive attempts initiated later in the breeding season often have reduced nest, pre-fledging, and post-fledging brood survival. We evaluated renesting propensity, renesting intervals, and renest reproductive success of Piping Plovers ( Charadrius melodus ) by following 1,922 nests and 1,785 unique breeding adults from 2014 to 2016 in the Northern Great Plains of the United States. The apparent renesting rate for individuals was 25% for reproductive attempts that failed in the nest stage (egg laying and incubation) and only 1.2% for reproductive attempts when broods were lost. Renesting propensity declined if reproductive attempts failed during the brood-rearing stage, nests were depredated, reproductive failure occurred later in the breeding season, or individuals had previously renested that year. Additionally, plovers that nested on reservoirs were less likely to renest compared to other habitats. Renesting intervals declined when individuals had not already renested, were after-second-year adults without known prior breeding experience, and moved short distances between nest attempts. Renesting intervals also decreased if the attempt failed later in the season. Overall, reproductive success and daily nest survival were lower for renests than first nests throughout the breeding season. Furthermore, renests on reservoirs had reduced apparent reproductive success and daily nest survival unless the predicted amount of habitat on reservoirs increased within the breeding season. Our results provide important demographic measures for this threatened species and suggest that predation- and water-management strategies that maximize success of early nests would be more likely to increase productivity. Altogether, renesting appears to be an unproductive reproductive strategy to replace lost reproductive attempts for Piping Plovers breeding in the Northern Great Plains.

Montana, North Dakota, South Dakota↗

USGS2019

Demographic responses of least terns and piping plovers to the 2011 Missouri River flood—A large-scale case study

A catastrophic flood event on the Missouri River system in 2011 led to substantial changes in abundance and distribution of unvegetated sand habitat. This river system is a major component of the breeding range for interior Least terns ( Sternula antillarum ; “terns”) and piping plovers ( Charadrius melodus ; “plovers”), both of which are Federally listed ground-nesting birds that prefer open, unvegetated sand and gravel nesting substrates on sandbars and shorelines. The 2011 flood inundated essentially all tern and plover nesting habitat during 2011, but it had potential to generate post-flood habitat conditions that favored use by terns and plovers in subsequent years. We compared several tern and plover demographic parameters during the pre-flood and post-flood periods on the Garrison Reach and Lake Sakakawea, North Dakota, to determine how this event influenced these species (both species on the Garrison Reach, and plovers only on Lake Sakakawea). The principal parameters we measured (nest survival, chick survival, and breeding population) showed spatial and temporal variation typical of opportunistic species occupying highly variable habitats. There was little evidence that nest survival of least terns differed between pre- and post-flood. During 2012 when habitat was most abundant on the Garrison Reach and Lake Sakakawea, piping plover nest survival was higher than in any other year in the study, but returned to rates comparable to pre-flood years in 2013. Chick survival for terns on the Garrison Reach and plovers on Lake Sakakawea showed a similar pattern to plover nest survival, with the 2012 rate exceeding all other years of the study, and the remaining pre-flood and post-flood years being generally similar but slightly higher in post-flood years. However, plover chick survival on the Garrison Reach in 2012 was similar to pre-flood years, and increased annually thereafter to its highest rate in 2014. Although wide confidence intervals precluded firm conclusions about flood effects on breeding populations, the general pattern suggested lower populations of plovers but higher populations of least terns immediately after the flood. Despite near total absence of breeding habitat on either study area during the flood of 2011, populations of both species persisted after the flood due to their propensity to disperse and/or forgo breeding for at least a year. Tern and plover populations have similarly persisted and recovered after the flood, but their mechanisms for persistence likely differ. Data on tern dispersal is generally lacking, but they are thought to show little fidelity to their natal grounds, have a propensity to disperse potentially long distances, and routinely forgo breeding until their second year, thus a lost opportunity to breed in a given area may be easily overcome. Plovers exhibit stronger demographic ties to the general area in which they previously nested, yet they occupy much broader nesting habitat features than terns and exploit three major landforms in the Dakotas (free-flowing rivers, reservoir shorelines, and wetland shorelines). Consequently, dispersal to and from non-Missouri River habitats and potential to exploit non-traditional habitats likely sustained the Northern Great Plains population through the flood event. Terns and plovers normally occupy similar habitats on the Missouri River and both species experienced similar loss of a breeding season due to the flood. Persistence of these populations after the flood underscores the importance of understanding their unique demographic characteristics and the context within which the Missouri River operates.

North Dakota↗