Colony Island Network Design and Implementation (CINDI): A Prioritization Tool to Rehabilitate Colony Islands Along the Texas Coast

Every four years the Texas General Land Office produces an updated Texas Coastal Resiliency Master Plan (CRMP) that includes a list of high priority (“Tier 1”) colonial waterbird nesting islands in need of rehabilitation. The basis for including an island in the Tier 1 list and for selecting which Tier 1 projects to implement, is based on expert opinion with little understanding of how an individual rehabilitated island contributes to the regional population of birds.  With 300 colony islands on the Texas coast, agencies do not have enough funds to intensively manage all of them. Nor do all islands have the same potential to increase regional waterbird populations.  Therefore, a data-driven prioritization tool that incorporates bio-geo-physical constraints on nesting, as well as economic considerations, is needed by third-party colony island advocates to prioritize colony island projects for inclusion in the Tier 1 category of the CRMP and for movement from the Tier-1 list to implementation.

The goal of CINDI is to co-produce and implement a prioritization tool that helps managers prioritize a network of colony islands where rehabilitation and management are cost effective and the potential for enhancing waterbird populations is high. To achieve this, natural resource managers must better understand how colony island traits, foraging habitat, and landscape characteristics influence waterbird breeding productivity. The association between colony traits and colony nesting success will be determined by measuring the number of chicks produced across a range of colony types for 5 focal bird species (Black Skimmer, Caspian Tern, Tricolored Heron, Reddish Egret, and Great Egret) using drones. Movement data from radio-tagged birds will be used to map foraging ranges and develop a model to estimate the probability of habitat. Existing monitoring data on small fish from the Texas Parks and Wildlife Department will be used as a measure of prey availability within species-specific foraging ranges. The prioritization tool will use a statistical programming algorithm to identify a set of colonies that maximizes colony persistence, nest survival, and access to foraging habitat with a high probability of use, while minimizing project costs. 

This project uses a co-production process to set conservation targets that define the conservation planning problem solved by the prioritization tool. The co-production process helps ensure that the maps have a high probability of being adopted by the natural resource managers who were involved in their development.

Natural Resource Managers involved include:

• Dr. David Newstead, Coastal Bend Bays & Estuaries Program
• Shelley Todd, National Park Service
• Alexis Baldera, Texas Audubon Society