Raptors in Temperate Grasslands: Ecology of Ferruginous Hawk, Golden Eagle, and Northern Harrier in the Northern Great Plains

Ferruginous hawks (Buteo regalis) are a grassland and shrubland obligate nesting raptor and prefer lightly grazed pasture or idle areas for nesting. Their population reportedly declines in number if more than 30% of an area is cultivated and they rarely nest in areas dominated by croplands. Golden eagles (Aquila chrysaetos) are long-lived raptors with high nest-site fidelity and relatively low reproductive success. Population trends of golden eagles in western United States are unclear although long-term monitoring of populations shows declines in occupancy and breeding performance. Northern harriers (Circus cyaneus) prefer relatively open grasslands and wetland areas of various natures. During the breeding season from 2013–2015, we investigated the influence of factors associated with the landscape on survival and nest-site selection of ferruginous hawks, golden eagles, and northern harriers in the northern Great Plains (north-central South Dakota, south-central North Dakota hereafter, Eastern Dakota [ED], and northwestern South Dakota hereafter, Western Dakota [WD]). Using ground and aerial surveys, we located and monitored active ferruginous hawk, golden eagle, and northern harrier nests (ferruginous hawk, n = 55; golden eagle. n = 35; northern harrier, n = 22). In ED, one pair of ferruginous hawk was found every 655 km2. In a more suitable subset of 4420 km2 in ED, we found one pair per 340 km2. In WD, we documented one breeding pair in 315 km2. In ED, all ferruginous hawk nests were in trees, and apparent nest success was 62% in 2013, 94% in 2014, and 87% in 2015. In WD, apparent nest success was 62% in 2013, 43% in 2014 and 94% in 2015. Overall, 101 ferruginous hawk chicks fledged in ED; 2.4 fledglings/successful nest, and 100 chicks fledged in WD; 2.6 fledglings/successful nest. In WD golden eagle pairs were documented with one nest every 1740.4 km2 for the duration of the study. Active nests of golden eagles were placed on two different substrates (i.e., steep cliff-side [n = 5] and trees [n = 30]) and apparent nest success was 62% in 2013, 94% in 2014, and 87% in 2015. Overall, 41 golden eagle chicks successfully fledged; 1.4 chicks/successful nest (SE = 0.09). Cottonwood (Populus deltoides) was the sole tree of choice for nesting golden eagles in WD (n = 30) followed by steep cliff-side (n = 5). No golden eagle nest was documented in ED. During breeding seasons in 2013 and 2014, one breeding pair of northern harrier was found every 370.6 km2. Most northern harrier nests were in seasonal or permanent wetlands with cordgrass (Spartina spp; n = 12), bulrush (Scirpus spp.; n = 6), cattail (Typha spp.; n = 3), and residual corn (Zea mays; n = 1). Apparent nest success was 25% in 2013, and 70% in 2014. During the 2013 breeding season, 3 of 12 active nests fledged 7 chicks (2.3 chicks/successful nest). During 2014, 7 of 10 active nests fledged 22 chicks (3.1 chicks/successful nest); overall, 29 (2.9 chicks/successful nest) nestlings fledged in our study area. We used Program MARK to evaluate the influence of land cover on nest success. The top-ranked nest survival model for ferruginous hawks in ED was SNull (wi= 0.87) suggesting that none of the landscape predictor variables had any effect on survival and survival probability was constant between years; it also may suggest low sample size and an inability to detect an effect. Probability of nest survival during the study period in ED was 0.69 (95% CI = 0.61–0.83). In WD, the top-ranked nest survival model for ferruginous hawks was SSubstrate suggesting nest substrate had most influence on nest survival in WD; the probability of ground nest survival during the study was 0.77 (95% CI = 0.64–0.83) and the probability of tree nest survival during the study was 0.43 (95% CI = 0.28–0.56). We used logistic regression analysis to evaluate the influence of landscape variables on nest site selection. In ED, percent grass and percent pasture/hay was the top-ranked model for predicting nest site selection of ferruginous hawks and indicated positive association of nest-site selection with grasslands and pasture. In WD, percent grass and development was the top-ranked model indicating positive influence of grasslands and development on nest-site selection. . Top-ranked nest survival model for golden eagle was SNull (wi = 0.91) suggesting that none of the predictor variables had any effect on survival and survival was constant between years. Probability of golden eagle nest survival during the study period was 0.76 (95% CI = 0.58–0.81). We used logistic regression analysis to evaluate the influence of landscape variables on nest-site selection of golden eagles. Development was the top-ranked model (wi = 0.72) for predicting nest site selection of golden eagles and indicated negative association of nest-site selection with development. The model containing grass, pasture, and development ranked second and was competitive indicating positive association of active nests with higher percentages of grass and negative association with increase in development. The top-ranked nest survival model was SYear (wi = 0.65) suggesting survival was different between the 2013 and 2014 breeding seasons. S%Grass+%Water+Year model wi =0.23: ≤4 ΔAICc away) also was competitive indicating positive relationship of nests with %grass and % water in the landscape. Estimated nest survival for northern harriers in 2013 was 0.21 (95% CI = 0.22–0.55), and in 2014 was 0.49 (95% CI = 0.32–0.61). We used logistic regression analysis to evaluate the influence of landscape variables on nest-site selection. Grass, pasture, and water ranked as the top model for northern harrier (wi = 0.87). Logistic odds-ratio estimates from the top-ranked model for northern harrier indicated the odds of nest-site selection were 1.48 (95% CI = 1.27–1.58) times greater for every percent increase in grasslands, and 1.2 (95% CI = 1.06–1.31) times greater for every percent increase in water; logistic odds ratio for percent pasture indicated no effect at the 900-m scale (1.06, 95% CI = 0.98–1.14). Our results indicate major decline of nesting ferruginous hawks in agriculture dominated regions of the northern Great Plains where land-use change has modified open grassland and pastures into row crop agriculture in the last four decades. Our study also demonstrate close association of grassland, pastures and wetlands with nest-site selection of ferruginous hawks, golden eagles and northern harriers, and avoidance of ground based disturbance by all three raptor species. Our findings indicate a need to manage pasture, wetlands, and grasslands in areas suitable for nesting of ferruginous hawks, golden eagles, and northern harriers and control increased fragmentation to support all grassland nesting raptors in the northern Great Plains

MILDSum: A Novel Benchmark Dataset for Multilingual Summarization of Indian Legal Case Judgments

Automatic summarization of legal case judgments is a practically important problem that has attracted substantial research efforts in many countries. In the context of the Indian judiciary, there is an additional complexity -- Indian legal case judgments are mostly written in complex English, but a significant portion of India's population lacks command of the English language. Hence, it is crucial to summarize the legal documents in Indian languages to ensure equitable access to justice. While prior research primarily focuses on summarizing legal case judgments in their source languages, this study presents a pioneering effort toward cross-lingual summarization of English legal documents into Hindi, the most frequently spoken Indian language. We construct the first high-quality legal corpus comprising of 3,122 case judgments from prominent Indian courts in English, along with their summaries in both English and Hindi, drafted by legal practitioners. We benchmark the performance of several diverse summarization approaches on our corpus and demonstrate the need for further research in cross-lingual summarization in the legal domain.Comment: Accepted at EMNLP 2023 (Main Conference

Buteo Nesting Ecology: Evaluating Nesting of Swainson’s Hawks in the Northern Great Plains

Swainson’s hawks (Buteo swainsoni) are long-distance migratory raptors that nest primarily in isolated trees located in areas of high grassland density. In recent years, anthropogenic conversion of grassland habitat has raised concerns about the status of the breeding population in the northern Great Plains. In 2013, we initiated a study to investigate the influence of extrinsic factors influencing Swainson’s hawk nesting ecology in north-central South Dakota and south-central North Dakota. Using ground and aerial surveys, we located and monitored nesting Swainson’s hawk pairs: 73 in 2013 and 120 in 2014. We documented 98 successful breeding attempts that fledged 163 chicks; 1.52 and 1.72 fledglings per successful nest in 2013 and 2014, respectively. We used Program MARK to evaluate the influence of land cover on nest survival. The top model, SDist2Farm+%Hay, indicated that nest survival (fledging at least one chick) decreased as nests were located farther from farm sites and as the percent of hay cover increased within 1200-m of the nest site (34.4%; 95% CI = 27.6%–42.3%). We used logistic regression analysis to evaluate the influence of landscape variables on nest-site selection; Swainson’s hawks selected for nest sites located closer to roads. We suggest that tree belts associated with farm sites, whether occupied or not, provide critical breeding sites for Swainson’s hawks. Additionally, poor breeding success may be related to the late migratory behavior of this species which requires them to occupy marginal habitat due to other raptors occupying the most suitable habitat prior to Swainson’s hawks arriving to the breeding grounds

Spatial Ecology and Survival of Swainson\u27s Hawks (Buteo swainsoni) in the Northern Great Plains

In recent years, anthropogenic conversion of grassland habitat has raised concerns about the status of breeding Swainson\u27s Hawks (Buteo swainsoni) in the northern Great Plains region of North America. During 2013–2014, we captured breeding Swainson\u27s Hawks in north-central South Dakota and south-central North Dakota to estimate home-range size, determine adult survival rates during the breeding season, and evaluate habitat selection. We captured, radio-tagged, and monitored 13 Swainson\u27s Hawks in 2013, and captured two additional Swainson\u27s Hawks in 2014. In 2014, seven of 13 individuals initially captured in 2013 returned to the same breeding territory for the 2014 breeding season. Average 95% MCP home-range size in 2013 was 205.4 ha (SD = 135.3 ha, n = 10) and 211.1 ha (SD = 208.8 ha, n = 9) in 2014, and size did not differ between years (t13 = 0.07, P = 0.95), averaging 208.3 ha (SD = 244.9 ha, n = 19 home ranges measured for 12 birds) for the 2 yr of the study. Mean core home-range size (50% MCP) was 78.2 ha (SD =105.9 ha, n = 10) in 2013 and 59.7 ha (SD = 80.7 ha, n = 9) in 2014; core home-range areas also did not differ between years (t17 = −0.46, P = 0.65). Swainson\u27s Hawks did not select habitats in proportion to their availability in 2013 (χ42 = 781.99, P \u3c 0.001) and 2014 (χ40 \u3e 999.99, P \u3c 0.001). In 2013, breeding Swainson\u27s Hawks selected against wetland and grassland habitats and selected for trees as foraging habitats. Similarly, Swainson\u27s Hawks selected against grassland habitats for foraging in 2014. We used known-fate analysis in Program MARK to estimate adult survival during the breeding season. The top-ranked model indicated survival was constant at 0.94 (95% CI = 0.68–0.99) during the breeding season and did not differ between years. Our results suggest that Swainson\u27s Hawks maintain a moderately high degree of breeding-site fidelity and have home ranges smaller than those documented elsewhere, and that their home-range size is influenced positively by the presence of grasslands and negatively by development

West Nile Virus and Ferruginous Hawks (Buteo Regalis) in the Northern Great Plains

Emerging infectious diseases (EID) present significant threats to the conservation of global biodiversity (Daszak et al. 2000). Evaluating impacts (spatial, temporal and demographic) of EIDs on sensitive and declining wildlife populations is challenging because quantitative information is usually dependent on estimates rather than counts (Wobeser 2007) and mortality rates are seldom quantified with conventional monitoring (Naugle et al. 2005)

Mate Replacement and Alloparental Care in Ferruginous Hawk (Buteo regalis)

Alloparental care (i.e., care for unrelated offspring) has been documented in various avian species (Maxson 1978, Smith et al. 1996, Te Ila et al. 1997, Lislevand et al. 2001, Literak and Mraz 2011). A male replacement mate that encounters existing broods has options, which include alloparental care or infanticide. Infanticide may be beneficial in some species (Rohwer 1986, Kermott et al. 1990), but in long-lived avian species, like the ferruginous hawk (Buteo regalis) that do not renest within a season, infanticide might be detrimental. Adoption and rearing success likely provide direct evidence of competence of replacement mates as potential parents for future seasons, a benefit that might outweigh the investment of time and effort associated with adoption and rearing (after Rohwer 1986). Anticipated mating opportunity at the cost of adoption (Gori et al. 1996, Rohwer et al. 1999) may explain step-parental benevolence and therefore, in such a scenario would enhance individual fitness through subsequent recruitment of related young

WEST NILE VIRUS AND FERRUGINOUS HAWKS (BUTEO REGALIS) IN THE NORTHERN GREAT PLAINS

Emerging infectious diseases (EID) present significant threats to the conservation of global biodiversity (Daszak et al. 2000). Evaluating impacts (spatial, temporal and demographic) of EIDs on sensitive and declining wildlife populations is challenging because quantitative information is usually dependent on estimates rather than counts (Wobeser 2007) and mortality rates are seldom quantified with conventional monitoring (Naugle et al. 2005). West Nile virus (WNv), a mosquito-borne Flavivirus (family Flaviviridae; Komar 2001), was discovered in northwest Uganda in 1937 (Smithburn et al. 1940). First encountered in the western hemisphere in New York in 1999 (Nash et al. 2001), WNv has become enzootic in all 48 contiguous states, and has been reported from 96% of counties to date (Centers for Disease Control and Prevention [CDC] 2013). West Nile virus has been detected in 65 species of mosquito in the United States (CDC 2012) and its ability to establish and persist across ecosystems and hosts is illustrated by its extensive distribution (CDC 2013). West Nile virus infection has been reported in 326 avian species (CDC 2013). Among a more scarcely occurring avian guild like the raptors, the CDC Arbornet Surveillance System (1999 to 2004) have documented infection in 36 species (Nemeth et al. 2006), approximately 70% of all raptor species occurring in North America

Mate Replacement and Alloparental Care in Ferruginous Hawk

Alloparental care (i.e., care for unrelated offspring) has been documented in various avian species (Maxson 1978, Smith et al. 1996, Tella et al. 1997, Lislevand et al. 2001, Literak and Mraz 2011). A male replacement mate that encounters existing broods has options, which include alloparental care or infanticide. Infanticide may be beneficial in some species (Rohwer 1986, Kermott et al. 1990), but in long-lived avian species, like the ferruginous hawk (Buteo regalis) that do not renest within a season, infanticide might be detrimental. Adoption and rearing success likely provide direct evidence of competence of replacement mates as potential parents for future seasons, a benefit that might outweigh the investment of time and effort associated with adoption and rearing (after Rohwer 1986). Anticipated mating opportunity at the cost of adoption (Gori et al. 1996, Rohwer et al. 1999) may explain step-parental benevolence and therefore, in such a scenario would enhance individual fitness through subsequent recruitment of related young

Are Land-use Changes Reflected in Diets of Mourning Doves (Zenaida macroura) in Eastern South Dakota

Food habits of the mourning dove (Zenaida macroura) have been extensively studied in the southern United States (McClure 1943, Korschgen 1958, Carpenter 1971) and consist primarily of vegetable matter throughout their range (Beckwith 1959). Diet studies in several states have indicated agricultural crops, specifically corn and wheat, were the most readily consumed plant seeds (Korshgen 1958, Carpenter 1971). Similarities observed in diets of doves were dependent on the agricultural crops available within the area. For example, in Missouri, some seasonal variability was documented suggesting doves forage based on food availability as much as by food preference (Korschgen 1958). However, in the agriculturally dominated landscape of east central South Dakota (SD), the two most important food items for doves were green (Setaria viridis) and yellow foxtail (S. glauca; Van’t Hul and Jenks 1992)