Linking landscape-scale conservation to regional and continental outcomes for a migratory species

Abstract

Land-use intensification on arable land is expanding and posing a threat to biodiversity and ecosystem services worldwide. We develop methods to link funding for avian breeding habitat conservation and management at landscape scales to equilibrium abundance of a migratory species at the continental scale. We apply this novel approach to a harvested bird valued by birders and hunters in north America, the northern pintail duck (Anas acuta), a species well below its population goal. Based on empirical observations from 2007-2016, habitat conservation investments for waterfowl cost $313 M and affected <2% of the pintail's primary breeding area in the Prairie Pothole Region of Canada. Realistic scenarios for harvest and habitat conservation costing an estimated $588 M (2016 USD) led to predicted pintail population sizes <3 M when assuming average parameter values. Accounting for parameter uncertainty, converting 70-100% of these croplands to idle grassland (cost: $35.7B-50B) is required to achieve the continental population goal of 4 M individuals under the current harvest policy. Using our work as a starting point, we propose continued development of modeling approaches that link conservation funding, habitat delivery, and population response to better integrate conservation efforts and harvest management of economically important migratory species. The expansion of intensive agriculture threatens the diversity of species 1-4 and ecosystem services 5 associated with arable landscapes. Growing demands for food, feed, fuel, and fiber have precipitated such land-use intensification in these and other landscapes worldwide 6,7. Substantial evidence shows that people benefit from high levels of biodiversity through many associated ecosystem services including food security, water quality, and recreation 8,9. Birds are valued by the general public and recreationists, including birders and hunters in the case of game species 10-12. Some grassland and farmland birds have undergone especially steep declines tied to intensifying agricultural practices 13. Many of these populations comprise individuals undertaking annual long-distance movements between breeding and wintering grounds often spanning multiple countries 14,15. International funds for conserving critical habitats at the landscape scale in North America are essential for maintaining these populations 16,17 and these resources vary over time 18. This conservation challenge begs the question of how shifts in funding and resultant changes in landscape composition might affect migratory birds. Important advances have been made in modeling impacts of habitat changes on migratory birds at regional and continental scales. Existing approaches have important limitations, however. Some lack landscape-level scenarios for habitat conservation 19-21 , while others focus on hypothetical species 22. Case studies most commonly lack predicted changes in species-specific abundance, predicting instead shifts in community-level metrics 23,24 or indices of habitat suitability 25-27. Spec...

Local population collapse of Ross's and lesser snow geese driven by failing recruitment and diminished philopatry

“…Quantifying mechanisms of population change in animals is essential for contextualizing observed population patterns (Williams et al 2002). Further, demographic results can inform the development of scenarios to guide management that targets proximate mechanisms to reduce highly abundant populations or increase vulnerable populations (Zhao et al 2019, 2020, Mattsson et al 2020). Most research with free‐ranging animal populations focuses on drivers of change in recruitment and survival.…”

Limited shifts in the distribution of migratory bird breeding habitat density in response to future changes in climate

“…The disproportionate importance of the PPR for a large number of species and the vulnerability of prairie-pothole wetlands to climate and land-use change has led to tens of millions of dollars being spent annually in the PPR to fund habitat-management programs aimed at the Accepted Article conservation of waterbird species (Mattsson et al 2020). Additionally, multiple wetland monitoring efforts have been sustained for over three decades and enabled the development of different modeling tools and approaches to assess how climate change could impact wetlands and waterbirds in the PPR (Johnson and Poiani 2016, McIntyre et al 2019, McKenna et al 2019.…”

Using ecosystem services to identify inequitable outcomes in migratory species conservation

“…Pintails migrate between their winter habitat in California and coastal areas of the Gulf of Mexico (the United States and Mexico) and their two major summer breeding grounds of (1) far northern Canada and Alaska and (2) the prairie potholes region (PPR) of the northern Great Plains of the United States and Canada (Clark et al., 2014). Pintail populations declined ∼50% to ∼3 million individuals in the mid‐20th century and, unlike other migratory waterfowl species, have failed to recover (Mattsson et al., 2012; Mattsson et al., 2020b; USFWS, 2018a).…”

“…At the same time that conservation payments are benefiting settler‐colonial agricultural operations for wetland habitat protection and restoration, the management effort by Indigenous groups is not being rewarded with conservation payments. If not curtailed further, the continued loss of prairie pothole habitat may continue to undermine the recovery of pintails and may also make the northern Canadian and Alaskan breeding regions more important as a “source” of pintails (Mattsson et al., 2020b), both for Indigenous communities and for regions in the United States and Mexico receiving spatial subsidies.…”