My coauthors and I are pleased to announce the publication of our recent open-access paper describing a new multi-event mark-recapture model to estimate reproductive and survival rates for species that exhibit extended parental care (e.g., belugas, dolphins, manatees) and for which offspring age is uncertain. We also provide the first robust estimates of the reproductive and juvenile survival rates of the endangered beluga whale population that resides in Cook Inlet, Alaska, USA. Citation: Himes Boor, G. K., McGuire, T. L., Warlick, A. J., Taylor, R. L., Converse, S. J., McClung, J. R., and Stephens, A. D., 2022, Estimating reproductive and juvenile survival rates when offspring ages are uncertain: a novel multievent mark-resight model with beluga whale case study: Methods in Ecology and Evolution, https://besjournals.onlinelibrary.wiley.com/doi/abs/10.1111/2041-210X.14 [nam10.safelinks.protection.outlook.com]<https://urldefense.com/v3/__https:/nam10.safelinks.protection.outlook.com/?url=https*3A*2F*2Furldefense.com*2Fv3*2F__https*3A*2F*2Fnam10.safelinks.protection.outlook.com*2F*3Furl*3Dhttps*3A*2F*2Fbesjournals.onlinelibrary.wiley.com*2Fdoi*2Fabs*2F10.1111*2F2041-210X.14*26data*3D05*7C01*7Cgkhimesboor*40montana.edu*7C53f9d3540bd74c668ec508dac2ce08eb*7C324aa97a03a644fc91e43846fbced113*7C0*7C0*7C638036487418345970*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000*7C*7C*7C*26sdata*3DckbTeqv6ATOnlG3XqbC6k3sSDJ24xoEs6nbqIsAlFXs*3D*26reserved*3D0__*3BJSUlJSUlJSUlJSUlJSUlJSUlJSUlJSU!!N11eV2iwtfs!pHk6tV0lQkSBXGiNA4SMfZNCA2m5FTAvVkW6KZa0zyZLNo4edkx8D79l2zzumxznM-JzQ0Kile8VdrYS25BJxA*24&data=05*7C01*7Cgkhimesboor*40montana.edu*7C6f59ca3f793a4d40838d08dac39415d3*7C324aa97a03a644fc91e43846fbced113*7C0*7C0*7C638037338055725909*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000*7C*7C*7C&sdata=*2FqFvpB46He0MAtusEW3TJXqvzLcO1UVYSUyopOSlkO0*3D&reserved=0__;JSUlJSUlJSUlJSUqKioqKioqJSUqKioqKioqKioqKioqKiolJSolJSUlJSUlJSUlJSUlJSUlJSUlJSU!!K-Hz7m0Vt54!nm0D66jJzPczo3u5u6c6FLc3iATkLwVTAmvgZRdIJjLPQpheow5f8GNu-Z2jxujERab5NXQo2xyukALxeyK1LWg$>032 Abstract: 1. Understanding the survival and reproductive rates of a population is critical to determining its long-term dynamics and viability. Mark-resight models are often used to estimate these demographic rates, but estimation of survival and reproductive rates is challenging, especially for wide-ranging, patchily distributed, or cryptic species. In particular, existing mark-resight models cannot accommodate data from populations in which offspring remain with parents for multiple years, are not always detected, and cannot be aged with certainty. 2. Here we describe a Bayesian multievent mark-resight modelling framework that uses all available adult and adult-offspring sightings (including sightings with older offspring of uncertain age) to estimate reproductive rates and survival rates of adults and juveniles. We extend existing multievent mark-resight models that typically only incorporate adult breeding state uncertainty by additionally accounting for age uncertainty in unmarked offspring and uncertainty in the duration of the mother-offspring association. We describe our model in general terms and with a simple illustrative example, then apply it in a more complex empirical setting using thirteen years of photo-ID data from a critically endangered population of beluga whales (Delphinapterus leucas). We evaluated model performance using simulated data under a range of sample sizes, and adult and offspring detection rates. 3. Applying our model to the beluga data yielded precise estimates for all demographic rates of interest despite substantial uncertainty in calf ages, including non-breeder survival and reproductive rates lower than that estimated for other beluga populations. Simulations suggested our model yields asymptotically unbiased parameter estimates with good precision and low bias even with moderate sample sizes and detection rates. 4. This work represents an important new development in multievent mark-resight modeling, allowing estimation of reproductive and juvenile survival rates for populations with extended adult - offspring associations and uncertain offspring ages (e.g., some marine mammals, elephants, bears, great apes, bats, and birds). Our model facilitated estimation of robust demographic rates for an endangered beluga population that were previously inestimable (e.g., non-breeder and juvenile survival, reproductive rate) and that will yield new insights into this population's continued decline. ________________________ Gina K. Himes Boor, PhD (she/her/hers) Assistant Research Professor Ecology Department Montana State University AJMJ 221B 406-580-1368